THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA DAVIS Digitized by the Internet Archive in 2012 with funding from University of California, Davis Libraries http://www.archive.org/details/waterutilization02cali Use of Water in California Courtesy San Jose Chamber of Commerce STATE OF CALIFORNIA GOODWIN J. KNIGHT GOVERNOR PUBLICATION OF STATE WATER RESOURCES BOARD Bulletin No. 2 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Volume I TEXT June, 1955 LIBRARY UNIVERSITY OF CAUFOR!'"* DAVIS TABLE OF CONTENTS Page LETTER OF TRANSMITTAL, STATE WATER RESOURCES BOARD 13 ACKNOWLEDGMENT 14 ORGANIZATION, STATE WATER RESOURCES BOARD 15 ORGANIZATION, STATE DEPARTMENT OF PUBLIC WORKS, DIVISION OF WATER RESOURCES- 16 ORGANIZATIONAL CHANGES - 17 PREFACE— CURRENT STATUS OF WATER SUPPLY DEVELOPMENT AND REQUIREMENTS IN CALIFORNIA- 19 CHAPTER I. INTRODUCTION _ Need for Determination of Present Use of Water and of Ultimate Water Requirement Authority and Funds for Investigation- History of Water Development in California The California Water Problem- Previous Investigations Objective of State-wide Water Resources Investi- gation Scope of Bulletin General Considerations Relating to Water Utili- zation in California Water Supply Irrigation Urban Use of Water Hydroelectric Power Timber and Minerals Recreation and Fish and Wildlife Repulsion of Sea Water Flood Control Drainage Salt Balance •^ Water Quality Costs of Water Page 21 21 22 22 24 25 25 26 27 27 28 30 31 32 32 34 34 35 35 36 37 CHAPTER II. METHODS AND PROCE- DURES 39 Definitions 39 Geographical Subdivision of California-. 40 Classification of Water Service Areas 41 Maps 41 General Description of Method of Determining Water Requirements 42 Surveys of Present Water Service Areas 43 Irrigated Lands ._ 43 Urban and Suburban Areas 1 44 Metropolitan Areas 44 Unclassified Areas 44 Method of Forecasting Ultimate Water Service Areas 45 Irrigable and Irrigated Lands 45 Standards for Determination of Irrigability of Lands 45 Land Classification Survey Procedure— 46 Determination of Irrigable Lands That Will Ultimately Be Irrigated 47 Probable Ultimate Crop Pattern 47 Urban and Suburban Areas 48 Metropolitan Areas 48 Other Water Service Areas 48 Techniques for Determining Land Areas Determination of Unit Values of Water Use — Irrigation Water Use General Method Special Methods Urban and Suburban Water Use Use of Water in Metropolitan Areas Use of Water in Other Water Service Areas 49 49 49 50 51 53 53 54 Determination of Water Requirements 54 Present Requirements 55 Ultimate Requirements 55 Probable Ultimate Supplemental Water Require- ments 56 Determination of Probable Ultimate Water Re- quirement of Metropolitan Areas by Popula- tion-Saturation Method 57 CHAPTER III. NORTH COASTAL AREA 59 Present Water Service Areas 62 Irrigated Lands 62 Urban and Suburban Water Service Areas— 64 Unclassified Areas 64 Summary 65 Probable Ultimate Water Service Areas. 65 Irrigated Lands 65 Urban and Suburban Water Service Areas 66 Other Water Service Areas 66 Summary 67 (5) TABLE OF CONTENTS-Continued Page Unit Values of Water Use 68 Irrigation Water Use 68 Urban and Suburban Water Use 68 Use of Water in Other Water Service Areas 69 Consumptive Use of Water 70 Factors of Water Demand 70 Monthly Distribution of Water Demands 70 Irrigation Water Service Area Efficiency 71 Water Requirements 72 Requirements of a Nonconsumptive Nature 72 Fish and Wildlife 72 Hydroelectric Power 73 Flood Control 73 Timber and Timber By-products 74 Mining 75 Requirements of a Consumptive Nature 75 Supplemental Requirements 75 CHAPTER IV. SAN FRANCISCO BAY AREA 77 Present Water Service Areas 83 Irrigated Lands 83 Urban and Suburban Water Service Areas 85 Unclassified Areas 86 Summary 86 Probable Ultimate Water Service Areas 87 Tidelands and Submerged Lands Susceptible of Reclamation 87 Pattern of Ultimate Development 87 Irrigated Lands 88 Urban and Suburban Water Service Areas 88 Other Water Service Areas 90 Summary 90 Unit Values of Water Use 91 Irrigation Water Use 91 Urban and Suburban Water Use 91 Use of Water in Other Water Service Areas__ 93 Consumptive Use of Water 93 Factors of Water Demand 93 Losses in Urban Water Utility Systems__ 94 Distribution of Urban Water Demands— .__ 94 Irrigation Water Service Area Efficiency.- 95 Water Requirements 96 Requirements of a Nonconsumptive Nature 96 Flood Control 96 Pish and Wildlife^ 96 Repulsion of Salt-water Intrusion From Ground Water Basins 97 Salt Balance . 97 Requirements of a < 'onsumptive Nature 97 Supplemental Requirements 100 Safe yield of Local and Imported Water Supplies With Present Development 100 Allocation of Local and Imported Water Supplies . 101 Supplemental Water Requirements 101 Page CHAPTER V. CENTRAL COASTAL AREA 103 Present Water Service Areas 108 Irrigated Lands 109 Urban and Suburban Water Service Areas 109 Unclassified Areas 10!) Summary 111 Probable Ultimate Water Service Areas HI Irrigated Lands 111 Urban and Suburban Water Service Areas__ - 112 Other Water Service Areas 112 Summary 112 Unit Values of Water Use T . 112 Irrigation Water Use 112 Urban and Suburban Water Use 113 Use of Water in Other Water Service Areas 113 Consumptive Use of Water 115 Factors of Water Demand 115 Monthly Distribution of Water Demands - 116 Irrigation Water Service Area Efficiency 116 Water Requirements 117 Requirements of a Nonconsumptive Nature.. - 117 Fish and Wildlife 117 Flood Control IIS Subsurface Outflow From Ground Water Basins to Ocean 118 Requirements of a Consumptive Nature 118 Supplemental Requirements . 119 CHAPTER VI. SOUTH COASTAL AREA__ . 121 Present Water Service Areas 127 Irrigated Lands 127 Urban and Suburban Water Service Areas 129 Unclassified Areas 130 Summary 130 Probable Ultimate Water Service Areas . 131 Irrigated Lands 131 Urban and Suburban Water Service Areas __ 133 Other Water Service Areas 133 Summary 134 Unit Values of Water Use__ 134 Irrigation Water Use 135 Urban and Suburban Water Use 135 Use of Water in Other Water Service Areas 137 Consumptive Use of Water . 137 Factors of Water Demand . 138 Monthly Distribution of Water Demands.^ __ 138 Water Service Area Efficiency . 138 Water Requirements 139 Requirements of a Nonconsumptive Nature . 139 Fish and Wildlife . 140 Flood Control . 140 Subsurface Outflow From Ground Water Basins to Ocean 141 Salt Balance 444 (6) TABLE OF CONTENTS-Continued Page "Water Requirements — Continued Requirements of a Consumptive Nature 141 Supplemental Requirements 143 Safe Yield of Local Water Supplies With Present Development 143 Imported Water Supplies 143 Supplemental Water Requirements 144 CHAPTER VII. CENTRAL VALLEY AREA 145 Present Water Service Areas 153 Irrigated Lands 153 Urban and Suburban Water Service Areas 155 Unclassified Areas 155 Summary 159 Probable Ultimate AVater Service Areas 159 Irrigated Lands 159 Urban and Suburban Water Service Areas 160 Other Water Service Areas 161 Summary 161 Unit Values of Water Use 161 Irrigation Water Use 161 Urban and Suburban Water Use 163 Use of Water in Other Water Service Areas _ 163 Consumptive Use of Water 167 Factors of Water Demand 167 Monthly Distribution of Water Demands 167 Irrigation Water Service Area Efficiency 172 Water Requirements 172 Requirements of a Nonconsumptive Nature 172 Pish and Wildlife 172 Flood Control _ . 177 Navigation 180 Salinity Control 180 Hydroelectric Power 180 Requirements of a Consumptive Nature 181 Supplemental Requirements 183 CHAPTER VIII. LAHONTAN AREA__ _ 187 Present Water Service Areas 192 Irrigated Lands 192 Urban and Suburban Water Service Areas 192 Unclassified Areas 192 Summary 193 Probable Ultimate AVater Service Areas 194 Irrigated Lands 194 Urban and Suburban Water Service Areas 195 Other Water Service Areas 195 Summary 195 Unit Values of AVater Use 196 Irrigation AVater Use 196 Urban and Suburban AVater Use 196 Use of Water in Other Water Service Areas 197 Page Consumptive Use of AVater 198 Factors of AVater Demand 198 Monthly Distribution of AVater Demands 198 Irrigation Water Service Area Efficiency 199 Water Requirements 200 Requirements of a Nonconsumptive Nature 200 Fish and Wildlife 200 Hydroelectric Power 200 Mining 201 Timber 201 Requirements of a Consumptive Nature 201 Supplemental Requirements 202 CHAPTER IX. COLORADO DESERT AREA 203 Present Water Service Areas 208 Irrigated Lands 208 Urban and Suburban Water Service Areas 209 Unclassified Areas 209 Summary 211 Probable Ultimate Water Service Areas 211 Irrigated Lands 211 Urban and Suburban Water Service Areas 212 Other AVater Service Areas 213 Summary 213 Unit Values of Water Use 213 Irrigation Water Use 213 Urban and Suburban Water Service Areas 214 Other Water Service Areas 214 Consumptive Use of Water 215 Factors of Water Demand 215 Monthly Distribution of Water Demands 215 Irrigation Water Service Area Efficiency 216 Water Requirements 216 Requirements of a Nonconsumptive Nature 217 Flood Control 217 Fish and Wildlife 217 Alining _ 217 Hydroelectric Power 217 Requirements of a Consumptive Nature 217 Supplemental Requirements 218 CHAPTER X. SUMMARY 219 Present and Ultimate Water Service Areas 222 Irrigated Lands 222 Urban and Suburban Water Service Areas 222 Other Water Service Areas 223 Summary 223 Unit Values of Water Use 223 Consumptive Use of Applied Water 225 Water Requirements 225 Supplemental Water Requirements 226 Ultimate Export and Import of AVater 227 ( 7 ) TABLES Table No. Page 1 Standards for Classification of Lands as Irrigable — 46 2 Areas of Hydrographic Units, North Coastal Area — 59 3 Areas of Counties Within Boundaries of North Coastal Area 59 4 Population of Principal Urban Centers, North Coastal Area 60 5 Areas of Presently Irrigated Lands Within Hydro- graphic Units, North Coastal Area 64 6 Areas of Presently Irrigated Lands Within Counties, North Coastal Area 65 7 Summary of Present Water Service Areas Within Hydrographic Units, North Coastal Area 65 8 Summary of Present Water Service Areas Within Counties, North Coastal Area 66 9 Probable Ultimate Areas of Irrigated Lands Within Hydrographic Units, North Coastal Area 66 10 Probable Ultimate Areas of Irrigated Lands Within Counties, North Coastal Area 66 11 Probable Ultimate Pattern of Irrigated Crops, North Coastal Area 67 12 Other Water Service Areas Under Probable Ultimate Conditions, North Coastal Area 67 13 Summary of Probable Ultimate Water Service Areas, North Coastal Area 68 14 Estimated Mean Seasonal Unit Values of Consump- tive Use of Water on Irrigated Lands, North Coastal Area 68 15 Estimated Mean Seasonal Unit Values of Water De- livery in Urban and Suburban Areas, North Coastal Area 69 16 Estimated Mean Seasonal Consumptive Use of Water on Present Water Service Areas, North Coastal Area 70 17 Probable Mean Seasonal Consumptive Use of Water on Ultimate Water Service Areas, North Coastal Area 71 18 Distribution of Monthly Water Demands, North Coastal Area 71 19 Estimated Weighted Mean Irrigation Water Service Area Efficiency Within Hydrographic Units, North Coastal Area 72 20 Present Hydroelectric Power Development, North Coastal Area 73 21 Existing and Estimated Potential Hydroelectric Power Development, North Coastal Area 73 22 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water, North Coastal Area 74 23 Estimated Probable Ultimate Mean Seasonal Supple- mental Water Requirements, North Coastal Area 75 24 Areas of Hydrographic Units, San Francisco Bay Area 77 25 Areas of Counties Within Boundaries of San Fran- cisco Bay Area 77 26 Population of Principal Urban Centers, San Fran- cisco Bay Area 81 27 Areas of Presently Irrigated and Dry-farmed Lands Within Hydrographic Units, San Francisco Bay Area 83 28 Areas of Presently Irrigated and Dry-farmed Lands Within Counties, San Francisco Bay Area 85 29 Present Urban and Suburban Areas Within Hydro- graphic Units, San Francisco Bay Area 85 30 Present Urban and Suburban Areas Within Counties, San Francisco Bay Area 86 31 Summary of Present Water Service Areas Within Hydrographic Unils, San Francisco Bay Area 86 32 Summary of Present Water Service Areas Within Counties, San Francisco Bay Area 87 Table No. Page '.',?, Probable Ultimate Areas of Irrigated Lands Within Hydrographic Units, San Francisco Bay Area__ 34 Probable Ultimate Areas of Irrigated Lands Within Counties, San Francisco Bay Area 35 Patterns of Probable Ultimate Urban Development Within Hydrographic Units, San Francisco Bay Area 88 36 Probable Ultimate Urban and Suburban Areas Within Hydrographic Units, San Francisco Bay Area 89 37 Probable Ultimate Urban and Suburban Areas Within Counties, San Francisco Bay Area 89 38 Other Water Service Areas Under Probable Ultimate Conditions, San Francisco Bay Area 90 39 Summary of Probable Ultimate Water Service Areas, San Francisco Bay Area 90 40 Estimated Mean Seasonal Unit Values of Consump- tive Use of Water on Irrigated Lands. San Francisco Bay Area 91 41 Estimated Present and Probable Ultimate Mean Sea- sonal Unit Values of Water Delivery in Urban and Suburban Areas, San Francisco Bay Area 92 42 Estimated Mean Seasonal Consumptive Use of Water on Present Water Service Areas, San Francisco Bay Area 93 43 Probable Mean Seasonal Consumptive Use of Water on Ultimate Water Service Areas, San Francisco Bay Area 94 44 Distribution of Urban Water Deliveries by Land Use Classifications, San Francisco Bay Area 94 45 Average Distribution of Monthly Water Demands, San Francisco Bay Area 95 46 Estimated Weighted Mean Irrigation Water Service Area Efficiency Within Hydrographic Units, San Francisco Bay Area 95 47 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water, San Francisco Bay Area 99 48 Estimated Ultimate Mean Seasonal Water Require- ments as a Function of Type of Land Use, San Fran- cisco Bay Area 100 49 Estimated Ultimate Population, Per Capita Use of Water, and Urban Water Requirement, San Fran- cisco Bay Area 100 50 Estimated Presently Developed Safe Seasonal Yield of Local and Imported Water Supplies, San Fran- cisco Bay Area 101 51 Probable Ultimate Allocation of Presently Available Local and Imported Water Supplies. San Francisco Bay Area 101 52 Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Water Requirements, San Fran- cisco Bay Area 101 53 Areas of Hydrographic Units, Central Coastal Area 103 54 Areas of Counties Within Boundaries of Central Coastal Area 103 55 Population of Principal Urban Centers. Central Coastal Area 105 56 Areas of Presently Irrigated Lands Within Hydro- graphic Units, Central Coastal Area 110 57 Areas of Presently Irrigated Lands Within Counties, Central Coastal Area 110 58 Summary of Present Water Service Areas Within Hydrographic Units, Central Coastal Area 111 59 Summary of Present Water Service Areas Within Counties, Central Coastal Area 111 60 Probable Ultimate Areas of Irrigated Lands Within Hydrographic Units, Central Coastal Area 111 61 Probable Ultimate Areas of Irrigated Lands Within Counties, Central Coastal Area 111 (8) TABLES— Continued Table No. Page 62 Probable Ultimate Pattern of Irrigated Crops, Cen- tral Coastal Area 112 63 Other Water Service Areas Under Probable Ultimate Conditions, Central Coastal Area 113 64 Summary of Probable Ultimate Water Service Areas, Central Coastal Area 113 65 Estimated Mean Seasonal Unit Values of Consump- tive Use of Water on Irrigated Lands, Central Coastal Area 114 66 Estimated Mean Seasonal Unit Values of Water De- livery in Urban and Suburban Areas, Central Coastal Area 115 67 Estimated Mean Seasonal Consumptive Use of Water on Present Water Service Areas, Central Coastal Area 115 68 Probable Mean Seasonal Consumptive Use of Water on Ultimate Water Service Areas, Central Coastal Area 116 69 Distribution of Monthly Water Demands, Central Coastal Area 116 70 Estimated Weighted Mean Irrigation Water Service Ana Efficiency Within Hydrographic Units, Central Coastal Area 117 71 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water, Central Coastal Area 118 72 Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Water Requirements, Central Coastal Area 119 73 Areas of Hydrographic Units, South Coastal Area 121 74 Areas of Counties Within Boundaries of South Coastal Area 121 75 Population of Principal Urban Centers, South Coastal Area 123 76 Areas of Presently Irrigated Lands Within Hydro- graphic Units, South Coastal Area 129 77 Areas of Presently Irrigated Lands Within Counties, South Coastal Area 129 78 Present Urban and Suburban Areas AVithin Hydro- graphic Units, South Coastal Area 130 79 Present Urban and Suburban Areas Within Counties. South Coastal Area 130 80 Summary of Present Water Service Areas Within Hydrographic Units, South Coastal Area 130 81 Summary of Present Water Service Areas Within Counties, South Coastal Area 131 82 Probable Ultimate Areas of Irrigated Lands Within Hydrographic Units, South Coastal Area 131 83 Probable Ultimate Areas of Irrigated Lands Within Counties, South Coastal Area 131 84 Probable Ultimate Pattern of Irrigated Crops, South Coastal Area 133 85 Probable Ultimate Urban and Suburban Areas Within Hydrographic Units, South Coastal Area 134 86 Probable Ultimate Urban and Suburban Areas Within Counties, South Coastal Area 134 87 Other Water Service Areas Under Probable Ultimate Conditions, South Coastal Area 134 88 Summary of Probable Ultimate Water Service Areas, South Coastal Area 135 89 Estimated Mean Seasonal Unit Values of Consump- tive Use of Water on Irrigated Lands, South Coastal Area 135 90 Estimated Mean Seasonal Unit Values of Water De- livery and Consumptive Use of Water on Urban and Suburban Land Use Classifications, Los Angeles Hydrographic Unit 136 Table No. Page 91 Estimated Mean Seasonal Unit Values of Water De- livery to Urban and Suburban Land Use Classifica- tions, San Diego Hydrographic Unit 137 92 Estimated Weighted Mean Seasonal Unit Values of Water Delivery and Consumptive Use of Water on Gross Urban and Suburban Areas, South Coastal Area 137 93 Estimated Mean Seasonal Consumptive Use of Water on Present Water Service Areas, South Coastal Area 138 94 Probable Mean Seasonal Consumptive Use of Water on Ultimate Water Service Areas, South Coastal Area 138 95 Distribution of Monthly Water Demands, South Coastal Area 139 96 Estimated Weighted Mean Water Service Area Ef- ficiency Within Hydrographic Units, South Coastal Area 139 97 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water, South Coastal Area 142 98 Estimated Presently Developed Safe Seasonal Yield of Local Water Supplies, South Coastal Area 14."! 99 Estimated Present Seasonal Import, South Coastal Area 144 100 Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Water Requirements, South Coastal Area T 144 101 Areas of Hydrographic Units, Central Valley Area__ 147 102 Areas of Counties Within Boundaries of Central Val- ley Area 148 103 Population of Principal Urban Centers, Central Val- ley Area 149 104 Areas of Presently Irrigated Lands Within Hydro- graphic Units, Central Valley Area 156 105 Areas of Presently Irrigated Lands Within Counties, Central Valley Area - 159 106 Summary of Present Water Service Areas Within Hydrographic Units, Central Valley Area 160 107 Summary of Present Water Service Areas Within Counties, Central Valley Area 161 108 Probable Ultimate Areas of Irrigated Lands Within Hydrographic Units, Central Valley Area 162 109 Probable Ultimate Areas of Irrigated Lands Within Counties, Central Valley Area 163 110 Probable Ultimate Pattern of Irrigated Crops, Cen- tral Valley Area 164 111 Other Water Service Areas Under Probable Ultimate Conditions, Central Valley Area 166 112 Summary of Probable Ultimate Water Service Areas, Central Valley Area 168 113 Estimated Mean Seasonal Unit Values of Consump- tive Use of Water on Irrigated Lands, Central Val- ley Area 169 114 Estimated Mean Seasonal Unit Values of Water De- livery and Consumptive Use of Water in Urban and Suburban Areas, Central Valley Area 173 115 Estimated Mean Seasonal Consumptive Use of Water on Present Water Service Areas, Central Valley Area 174 116 Probable Mean Seasonal Consumptive Use of Water on Ultimate Water Service Areas, Central Valley Area 176 117 Distribution of Monthly Water Demands, Central Valley Area 178 118 Estimated Weighted Mean Irrigation Water Service Area Efficiency Within Hydrographic Units, Central Valley Area 179 (9) TABLES— Continued Table „ No. Pa e e 119 Present Hydroelectric Power Development, Central Valley Area 181 120 Existing and Estimated Potential Hydroelectric Power Development, Central Valley Area 181 121 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water in Hydrographic Units, Central Valley Area 182 122 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water in Major Basins, Cen- tral Valley Area 183 123 Seasonal Water Deliveries in San Joaquin River and Tulare Lake Basins Through Friant-Kern Canal 183 124 Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Water Requirements in Hydro- graphic Units, Central Valley Area 184 125 Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Water Requirements in Major Basins, Central Valley Area 185 126 Areas of Hydrographic Units, Lahontan Area 187 127 Areas of Counties Within Boundaries of Lahontan Area 187 128 Population of Principal Urban Centers, Lahontan Area 188 129 Areas of Presently Irrigated Lands Within Hydro- graphic Units, Lahontan Area 193 130 Areas of Presently Irrigated Lands Within Counties, Lahontan Area 193 131 Summary of Present Water Service Areas Within Hydrographic Units, Lahontan Area 194 132 Summary of Present Water Service Areas Within Counties, Lahontan Area 194 133 Probable Ultimate Areas of Irrigated Lands Within Hydrographic Units, Lahontan Area 194 134 Probable Ultimate Areas of Irrigated Lands Within Counties, Lahontan Area 194 135 Probable Ultimate Pattern of Irrigated Crops, La- hontan Area 195 136 Other Water Service Areas Under Probable Ultimate Conditions, Lahontan Area ' 196 137 Summary of Probable Ultimate Water Service Areas, Lahontan Area 196 138 Estimated Mean Seasonal Unit Values of Consump- tive Use of Water on Irrigated Lands, Lahontan Area 197 139 Estimated Mean Seasonal Unit Values of Water Delivery and Consumptive Use of Water on Urban and Suburban Areas, Lahontan Area 198 140 Estimated Mean Seasonal Consumptive Use of Water on Present Water Service Areas, Lahontan Area 198 141 Probable Mean Seasonal Consumptive Use of Water on Ultimate Water Service Areas, Lahontan Area 199 142 Distribution of Monthly Water Demands, Lahontan Area 199 143 Estimated Weighted Mean Irrigation Water Service Area Efficiency Within Hydrographic Units, La- hontan Area 200 144 Existing and Estimated Potential Hydroelectric Power Development, Lahontan Area 201 1 15 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water, Lahontan Area 201 146 Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Water Requirements, Lahontan Area 202 147 Areas of Hydrographic Units, Colorado Desert Area 203 148 Areas of Counties Within Boundaries of Colorado Deserl Area 203 Table No. Page 149 Population of Principal Urban Centers. Colorado Desert Area 205 150 Areas of Presently Irrigated Lands Within Hydro- graphic Units, Colorado Desert Area 209 151 Areas of Presently Irrigated Lands Within Counties, Colorado Desert Area 210 152 Summary of Present Water Service Areas Within Hydrographic Units, Colorado Desert Area - 211 153 Summary of Present Water Service Areas Within Counties, Colorado Desert Area 211 154 Probable Ultimate Areas of Irrigated Lands Within Hydrographic Units, Colorado Desert Area 212 155 Probable Ultimate Areas of Irrigated Lands Within Counties, Colorado Desert Area 212 156 Probable Ultimate Pattern of Irrigated Crops, Colo- rado Desert Area 212 157 Other Water Service Areas Under Probable Ultimate Conditions, Colorado Desert Area 213 158 Summary of Probable Ultimate Water Service Areas, Colorado Desert Area 213 159 Estimated Mean Seasonal Unit Values of Consump- tive Use of Water on Irrigated Lands, Colorado Desert Area 214 160 Estimated Mean Seasonal Unit Values of Water Delivery in Urban and Suburban Areas, Colorado Desert Area 214 161 Estimated Mean Seasonal Consumptive Use of Water on Present Water Service Areas, Colorado Desert Area 215 162 Probable Mean Seasonal Consumptive Use of Water on Ultimate Water Service Areas, Colorado Desert Area 215 163 Distribution of Monthly Water Demands, Colorado Desert Area 216 164 Estimated Weighted Mean Irrigation Water Service Area Efficiency Within Hydrographic Units, Colorado Desert Area 216 165 Estimated Mean Seasonal Requirements for Water on Present Water Service Areas, Colorado Desert Area 217 166 Probable Mean Seasonal Requirements for Water on Ultimate Water Service Areas, Colorado Desert Area 218 167 Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Water Requirements, Colorado Desert Area 218 168 Areas of Hydrographic Areas, State of California _ 219 169 Estimated Mean Seasonal Full Natural Runoff of Hydrographic Areas, State of California 220 170 Estimated Present and Probable Ultimate Population Within Hydrographic Areas, State of California 220 171 Areas of Presently Irrigated Lands Within Hydro- graphic Areas, State of California 222 172 Probable Ultimate Areas of Irrigated Lands Within Hydrographic Areas, State of California _ 223 173 Summary of Present Water Service Areas Within Hydrographic Areas, State of California 224 174 Summary of Probable Ultimate Water Service Areas Within Hydrographic Areas, State of California 224 175 Estimated Present Weighted Mean Seasonal Unit Values of Consumptive Use of Applied Water, State of California 225 176 Probable Ultimate Weighted Mean Seasonal Unit Values of Consumptive Use of Applied Water, State of California , 225 177 Estimated Mean Seasonal Consumptive Use of Ap- plied Water on Present Water Service Areas, State of California 225 ( 10) TABLES— Continued Table No. 178 179 Page Probable Mean Seasonal Consumptive Use of Applied Water on Ultimate Water Service Areas, State of California 225 Estimated Present and Probable Ultimate Mean Sea- sonal Requirements for Water, State of California— 220 Table No. 180 181 Page Estimated Present and Probable Ultimate Mean Sea- sonal Supplemental Requirements for Water, State of California 227 Summary of Estimated Ultimate Exports and Im- ports of Water in California 227 ILLUSTRATIONS Page Use of Water in California Frontispiece Fishing Fleet at Eureka 61 Sawmill in North Coastal Area 61 The Klamath River 63 Recreation in North Coastal Area 63 San Francisco 78 Santa Clara Valley Orchard 78 Urban Growth in San Francisco Bay Area 80 Urban Development in San Francisco S4 The Salinas Valley ___ _ 104 Harvesting Lettuce in Central Coastal Area 104 The Central Coast 107 Urban Growth in Los Angeles Metropolitan Area 122 Los Angeles Harbor 124 The Petroleum Industry in the South Coastal Area 124 Urban Development and Agriculture Near San Bernardino 128 Irrigated Lands in Ventura County 128 Urban Growth in San Diego Metropolitan Area 132 Page Mt. Shasta 146 Harvesting Celery in the Delta 150 Agriculture in Sacramento Valley 150 Harvesting Cotton Near Bakersfield 152 Vineyards in San Joaquin Valley 152 Urban Development in Central Valley Area . 154 Irrigation in the Delta 154 Navigation on Sacramento River 158 Hydroelectric Power Plant on the Feather River 158 Donner Summit 186 Lake Tahoe 186 Scene Near Susanville 190 The Sierra Nevada 190 Date Gardens Near Indio 204 Coachella Branch of All-American Canal 204 Diversion From Colorado River for Palo Verde Irrigation District 206 VOLUME II— TABLE OF CONTENTS APPENDIXES Page A. A Preliminary Projection of California Crop Patterns for Estimating Ultimate Water Requirements 231 B. Directory of Water Service Agencies in California 257 C. Description of Hydrographic Units 291 D. Sources and Dates of Land Use Survey Data _ 305 E. Sources of Land Classification Survey Data 307 P. Water Requirements for Fish and Wildlife in California 311 G. Hydroelectric Power Installations in California _ 325 H. Major Reservoirs of California 331 I. Water Quality Considerations Affecting Use of the Waters of Cali- fornia 339 (H) TABLE OF CONTENTS-Continued PLATES (Plates 1 to 15 at end of Volume II) Plate No. 1 Water Service Areas for The California Water Plan 2 Growth of Population and Cultivated and Irrigated Lands of California 3 Irrigation and Water Storage Districts 4 Valley Fill Areas 5 Electric Power Development, 1954 6 Timber Lands and Auriferous Gravel Deposits 7 Recreational Areas 8 Major Hydrographie Areas and Ilydrographic Units 9 Classification of Lands for Water Service From The California Water Plan 10 Present Land Use in San Francisco Bay Area 11 Present Land Use in Los Angeles and San Diego Metropolitan Areas 12 Principal Water Supply Agencies and Works of San Francisco Bay Area 13 Principal Water Supply Agencies and Works of Los Angeles and San Diego Metropolitan Areas 14 Imported Water Supplies of San Francisco Bay Area 15 Imported Water Supplies of Los Angeles and San Diego Metropolitan Areas l 12 ) LETTER OF TRANSMITTAL Goodwin J. Knight governor STATE OF CALIFORNIA STATE WATER RESOURCES BOARD PUBLIC WORKS BUILDING SACRAMENTO 5, CALIFORNIA CLAIR A. HILL, CHAIRMAN. REDDING R. V. MEIKLE, VICE CHAIRMAN. TURLOCK A. D. EDMONSTON, STATE ENGINEER SECRETARY June 30, 1955 A. FREW. King city C. A. GRIFFITH, AZUSA W P. RICH, MARYSV1LLE PENN ROWE, San Bernardino PHIL D. SWING. San Diego ADDRESS ALL COMMUNICATIONS TO THE SECRETARY Honorable Goodwin" J. Knight, Governor, and Members of the Legislature of the State of California Gentlemen : J have the honor to transmit herewith Bulletin No. 2 of the State Water Resources Board, entitled "Water Utilization and Requirements of Cali- fornia," authorization of which was initiated by Chapter 1541, Statutes of 1947. Under the provisions of the cited statute and subsequent budget acts, the Legislature directed the State Water Resources Board to make an investigation of the water resources of California and to formulate plans for the orderly development of such resources. Accordingly, the Board adopted a program of investigation and a budget at its regular meeting on September 5, 1947. Appro- priations required for continuance of the work have been made by the Legislature through the Fiscal Year 1955-56. The investigation is being conducted by the Division of Water Resources of the Department of Public Works, under the direction of the State Water Resources Board. Bulletin No. 2 presents results of a comprehensive analysis of present and probable ultimate use of water in California for irrigated agricultural, domestic, industrial, and other beneficial purposes. The bulletin contains estimates of the gross water requirements for all beneficial purposes, and of the amount of supplemental water required for satisfaction of present and probable ultimate needs throughout California. Very truly yours, {%^. ^ -rf-uS Clair A. Hn.i, Chairman (13 ) ACKNOWLEDGMENT Valuable assistance and data used in the investigation were contributed by agencies of the Federal Government and of the State of California, by cities, counties, public districts, and by private companies and individuals. This co- operation is gratefully acknowledged. Special mention is made of the helpful cooperation of the following : Bureau of Reclamation, United States Department of the Interior Forest Service, United States Department of Agriculture Fish and Wildlife Service, United States Department of the Interior Soil Conservation Service, United States Department of Agriculture Geological Survey, United States Department of the Interior Federal Power Commission California Department of Fish and Game California Public Utilities Commission University of California at Berkeley and at Davis East Bay Municipal Utility District Hetch Hetchy Water Supply, Power and Utilities Engineering Bureau, City of San Francisco Metropolitan Water District of Southern California Department of Water and Power, City of Los Angeles San Diego County Water Authority City of San Diego Pacific Gas and Electric Company Southern California Edison Company (14) ORGANIZATION STATE WATER RESOURCES BOARD CLAIR A. HILL, Chairman, Redding R. V. MEIKLE, Vice Chairman, Turlock A. FREW, King City W. PENN ROWE, San Bernardino C. A. GRIFFITH, Azusa PHIL D. SWING, San Diego W. P. RICH, Marysville A. D. EDMONSTON, State Engineer Secrefary and Engineer SAM R. LEEDOM, Administrative Assistant ( 15) ORGANIZATION STATE DEPARTMENT OF PUBLIC WORKS DIVISION OF WATER RESOURCES FRANK B. DURKEE Director of Public Works A. D. EDMONSTON State Engineer T. B. WADDELL Assistant State Engineer This bulletin was prepared under the direction of W. L BERRY, Principal Hydraulic Engineer by C. B. MEYER, Supervising Hydraulic Engineer and W. L. HORN, Supervising Hydraulic Engineer Assisted by H. A. HOWLETT Senior Hydraulic F. L. HOTES Senior Civil ERWIN DAMES Associate Hydraulic WILLIAM DURBROW Associate Hydraulic F. A. MAYNARD ... Associate Hydraulic F. NICOLAUS Associate Hydraulic T. PYLE Associate Hydraulic E. STEINER Associate Hydraulic W. COOK Assistant Hydraulic A. HOLT Assistant Hydraulic H. JAQUITH Assistant Hydraulic C. MACKEY ..Assistant Hydraulic D. MEIXNER, Jr ... Assistant Hydraulic J. PETERS Assistant Hydraulic E. RINEHART Assistant Hydraulic D. VAYDER Assistant Hydraulic J. G. WULFF Assistant Hydraulic Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Engineer Work in southern California was performed under the direction of MAX BOOKMAN Principal Hydraulic Engineer R. M. EDMONSTON Supervising Hydraulic Engineer Assisted by Supervising Hydraulic Engineer Senior Hydraulic Engineer Associate Hydraulic Engineer Hydraulic Engineer Assistant Hydraulic Engineer lunior Civil Engineer B. WILLETS I. BURNS M. CROOKER H. BORN ..Assistant O. POWELL R. SHIPPEY Geologic studies were performed under the direction of E. C. MARLIAVE Supervising Engineering Geologist Assisted by R. T. BEAN R. C. RICHTER Senior Engineering Geologist Senior Engineering Geologist Field and office activities in connection with land classification and crop distribution were under the supervision of J. W. SHANNON ...Land and Water Use Specialist Assisted by Associate Soil Technologist Photogrammetrist II Junior Civil Engineer R. N. HALEY H. E. ANDRUS R. R. STUART Sections of the report and the appendix dealing with water quality were prepared under the direction of HARVEY O. BANKS _ P. J. COFFEY Assistant State Engineer Supervising Hydraulic Engineer Assisted by W. R. SLATER Senior Hydraulic Engineer C. A. McCULLOUGH ...Senior Hydraulic Engineer J. H. LAWRENCE Associate Soil Technologist Maps and plates for the report were prepared under the supervision of Supervisor of Drafting Services J. L. JAMES Statistical and population studies were under the supervision of E. P. WARREN Associate Statistician Editing of the report was under the supervision of R. O. THOMAS Senior Hydraulic Engineer Legal HENRY HOLSINGER ... Principal Attorney Administrative T. R. MERRYWEATHER Administrative Officer ISABEL C. NESSLER Coordinator of Reports L. N. CASE Senior Stenographer-Clerk CONSULTANTS The appendix on California crop patterns was prepared by DR. DAVID WEEKS ... Professor of Agricultural Economics, University of California Studies of fish and wildlife problems were con- ducted in cooperation with the California Department of Fish and Game SETH GORDON ... Director R. M. PAUL .Water Projects Coordinator R. J. HALLOCK Senior Fisheries Biologist D. E. PELGEN — Associate Fisheries Biologist ( 1G ) ORGANIZATIONAL CHANGES At the time the investigation reported upon in this bulletin commenced, Royal Miller was Chairman of the State "Water Resources Board, and continued in that capacity until January 7, 1949, when he resigned as Chairman but con- tinued to serve as a member of the Board until January 15, 1953. Other members of the Board at the initiation of this study were H. J. Cozzens, B. A. Etcheverry, C. A. Griffith, R. V. Meikle, and Phil D. Swing. The remaining vacancy on the Board was filled by the appointment of Clair A. Hill on July 20, 1949. Mr. Griffith succeeded to the position of Chairman upon the resignation of Mr. Miller. W. P. Rich was appointed to the Board on October 25, 1953, to fill the vacancy resulting from Mr. Miller's retirement. Mr. Cozzens retired from the Board on January 1, 1954. The death of Mr. Etcheverry on October 26, 1954, removed from public life one of its outstanding engineers and citizens, and one whose wise counsel will be missed in the future. Arnold Frew was appointed to the Board on February 10, 1955, replacing Mr. Cozzens. Mr. Hill became Chairman on May 13, 1955, succeeding Mr. Griffith, who remained as a member of the Board. The vacancy left by the death of Mr. Etcheverry was filled by the appoint- ment of W. Penn Rowe on May 25, 1955. Edward Hyatt, former State Engineer and ex-officio Secretary and Engineer to the Board, retired from state service on January 31, 1950, and was succeeded by A. D. Edmonston. Mr. Hyatt died on June 17, 1954. Conduct of the State-wide Water Resources Investigation was under the direc- tion of P. H. Van Etten, Principal Hydraulic Engineer of the Division of Water Resources, from the initiation of studies for Bulletin No. 2 in 1948 until January 31, 1950, when he assumed the duties of Assistant State Engineer. T. R. Simpson, Principal Hydraulic Engineer, then assumed responsibility for direction of the investigation. Since Mr. Simpson's resignation from the Division of Water Resources on September 15, 1950, the investigation has been directed by W. L. Berry, Principal Hydraulic Engineer. ( 17 PREFACE CURRENT STATUS OF WATER SUPPLY DEVELOPMENT AND REQUIREMENTS IN CALIFORNIA Studies for the State-wide Water Resources In- vestigation to date indicate that California is faced with a substantial and rapidly increasing deficiency in developed water supplies as related to requirements for water. The urgency in this current problem is believed to be sufficient to warrant a statement in this respect prefatory to presentation of the material in this bulletin. Data set forth herein pertaining to so-called ' ' pres- ent" conditions of water utilization and requirement in California actually relate to the status of develop- ment as of about 1950. They are based largely upon field surveys conducted in 1949 and 1950, reports of cooperating agencies for 1950, and records of water supply and use as secured from operating utilities or as estimated by the Division of Water Resources for 1950 development. During the intervening years since 1950 the neces- sary office studies and analyses have been conducted and tli is bulletin prepared for publication. However, in this same period a very significant growth has oc- curred throughout California. Reliable estimates in- dicate that the population of the State has increased by about 18 per cent since 1950 to a present total of nearly 12,500,000, and that the net irrigated area has increased by about 13 per cent to some 7,750,000 acres. In 1950 the estimated mean seasonal deficiency in water supply development throughout the State amounted to nearly 2,700,000 acre-feet, While in most instances the lands representing this shortage were physically served with water, it was necessary to draw i n diminishing reserves, principally ground waters, in order to meet the deficiency. Such perennial over- draft has been increasing rapidly of recent years, and has resulted in accelerated lowering of ground water levels in many parts of the State. It is now evident that continuing overdrafts will not only drastically reduce the reserves in storage, but in many instances will irreparably damage the immensely valuable ground water reservoirs. Increased water requirements due to the growth of California since 1950 are estimated to aggregate about 3,200,000 acre-feet per season. However, since 1950, new water supplies have been made available through the Friant-Kern and Delta-Mendota Canals, and other recently constructed projects, in amounts which have partially offset the increased use. In some places the necessary additional water sup- plies could now be obtained by increasing imports within the potential capacity of existing works. As an examine, supplemental water now needed in the South Coastal Area, excepting only Ventura County, could be provided by increasing the imports from the Colo- rado River. Based upon reasonable forecasts of growth of the State over the next 10 years, it is indicated that the shortage in water supply development could amount to more than 10,000,000 acre-feet per season by 1965, even taking into account increasing importation from presently developed water sources. There is further reason for anxiety at the lag in timely water resource development in California. The estimated yields of our present works, as well as those planned for the future, are necessarily based on the assumption that the short recorded history of natural water occurrence will repeat itself in the future. Even if this should prove to be true, it is likely that there will be recurrence of extended drought periods such as have been experienced in the past, during which the water supply of the State over a number of years has averaged only a little more than 50 per cent of the recorded mean. If a severe drought should come concurrently with deficiencies in Avater supply devel- opment such as now exist, it could create widespread havoc and even economic disaster throughout Califor- nia, Futhermore, there is no reason to believe that drought conditions of the future could not be more intense and further extended than those of the short recorded past, (19) CHAPTER I INTRODUCTION This bulletin is the second of a series presenting the results of continuing surveys and studies being made under authorization of the Legislature and di- rection of the State Water Resources Board, with the objective of solving what is perhaps the most basic economic problem facing the people of California. That problem pertains to the conservation, control, and utilization of our abundant water resources for the greatest public benefit. An earlier publication of the State Water Re- sources Board, Bulletin No. 1, "Water Resources of California," which was released in 1951, brought to- gether in one volume the principal basic data that bad been accumulated up to 1947 regarding the oc- currence of water in California, and constituted an inventory of the water resources of the State. In logical sequence, this present volume comprises a de- termination of the present use of water throughout California and of the probable ultimate water re- quirement. Concurrently with the preparation of these first two bulletins in the series, work has pro- gressed on the remaining and principal phase of the investigation: formulation of "The California Water Plan," a comprehensive plan for the fullest prac- ticable conservation, control, protection and utiliza- tion of the water resources of California. NEED FOR DETERMINATION OF PRESENT USE OF WATER AND OF ULTIMATE WATER REQUIRE- MENT The continuing rapid development of California, which is evidenced by growth of population, expansion of industry, and increase in irrigated agriculture, has resulted in a greatly increased requirement for water. The population grew from 6,900,000 in 1940 to about 10,600,000 in 1950, and the 1954 population is esti- mated to be well over 12,000,000. This new popula- tion has imposed large additional demands upon agen- cies supplying water for domestic purposes. The re- cent industrial development of California has pro- ceeded at an even more rapid rate than the growth of population. While industrial water requirements vary over wide limits depending upon type and lo- cation of the industry, the average use of water in a typical industrialized area is about five times that in an equal area devoted to domestic residential pur- poses. Thus, the increase in industrial development has imposed heavy demands upon water supply agen- cies. However, by far the greatest requirement for water in California is for the irrigation of agricul- tural crops. Coincident with World War II and con- tinning at an unabated rate to the present date, there has been rapid expansion of the area devoted to irri- gated agriculture. There were about 7,000,000 acres under irrigation in this State as of 1950, according to field survey data. This constitutes an increase of roughly 1,500,000 acres since 1944. Irrigated lands require about 90 per cent of the water consumptively used within California and impose the most important draft upon the water supply. The general location of presently irrigated lands of California, as well as those considered suitable for future irrigation development, are shown on Plate 1, entitled "Water Service Areas for The California Water Plan." Plate 2, entitled "Growth of Popula- tion and Cultivated and Irrigated Lands of Cali- fornia," depicts graphically the growth of popula- tion, irrigation, and cultivated agricultural areas for the entire State by decades from 1850 to 1950. The data upon which this plate was based were largely de- rived from publications of the United States Bureau of the Census. In general, the responsible public and private agencies, as well as the people of CalifoiTiia, have been aware during recent years of the urgent need for water resource development, and have taken steps as they became necessary to meet the increasing water requirements. In certain instances this has re- sulted in the farsighted construction of outstanding conservation and distribution works, and in others in the enlargement and expansion of existing facili- ties. Also, there has been major construction of hydro- electric power facilities and of flood control works. In many cases the developments have been designed and operated to enhance the recreational opportuni- ties of the community and in the interest of the pres- ervation and propagation of fish and wildlife. How- ever, in large and important areas of California the new requirements for water have been met only by increasing the draft upon water stored in natural underground reservoirs at a rate beyond the replen- ishment to these basins. As a consequence, many such areas face the certainty of failing water supplies unless supplemental water is provided, and there is real danger of permanent and irreparable damage to the valuable ground water reservoirs through the introduction of water of inferior quality. It seems entirely probable that the economic, cli- matic, and other factors that have established the present pattern of growth of population, industry, and agriculture in California, will continue in the (21) 22 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA future. It is even more certain that significant growth of the State can only be made possible by further development of our water resources sufficient to pro- vide for the serious present deficiencies, as well as for the probable large added requirements of the future. Furthermore, experience indicates that such future water resource development should be based upon- comprehensive and coordinated planning, state-wide in its scope, in order that all parts of California may share equitably in the available water resources, and in order that no area shall suffer through want of water. It was in recognition of these important con- siderations that the Legislature authorized the State Water Resources Board to conduct the state-wide in- vestigation of water resources reported in this current series of bulletins. Several investigations of the water resources of California have been made in the past, but none were truly comprehensive in scope. Succeeding years have added to the basic records and generally to the knowledge of the water resources of the State. It is for this reason, and because planning for the future must start with a thorough understanding of the loca- tion, amount, and quality of the waters of the State, and of physical conditions which determine their oc- currence and availability, that the inventory of water resources contained in Bulletin No. 1 was compiled and published. Equally important to future planning is an understanding of the location, amount, and na- ture of the present development and use of water throughout the State, of the probable future use of water, and of the ultimate supplemental water re- quirement, which factors provide the subject matter of this bulletin. AUTHORITY AND FUNDS FOR INVESTIGATION The State Water Resources Act of 1945, as amended by Chapter 908, Statutes of 1947, invested in the State Water Resources Board broad powers to initiate and conduct investigations of the water resources of the State. Section 17(a) of the amended act reads as follows : "The Water Resources Board is authorized to conduct investigations of the water resources of the State ; to formulate plans for the control, conserva- tion, protection, and utilization of such water re- sources, including solutions for the water problems <>f each portion of the State as deemed expedient and economically feasible; and to render reports thereon." Chapter 1541, Statutes of 1947, appropriated $140,- <»()() to the Board Bor expenditure during the Fiscal Year 1947-48 in conducting investigations and other- wise carrying out the provisions of the State Water Resources Act, The Budget Acts of 1948 and subse- quent years through 1954 have made appropriations for continuance of the investigation and for prepara- tion of reports. HISTORY OF WATER DEVELOPMENT IN CALIFORNIA History of the use of water in California starts with the Spanish missions in the final third of the eighteenth century. Profiting by their experience in arid Baja California, the padres established most of the Alta California missions where water for irriga- tion was available. Except for some small Indian cul- tivations along the west bank of the Colorado River, it was in the mission "gardens" of fruits and vege- tables, and perhaps in occasional fields of grain, that irrigation in California had its beginnings. Even yet, a century and a half later, remnants of mission works to supply irrigation and domestic water may be seen, notably at San Diego Mission Dam on San Diego River, and at Santa Barbara Mission Dam and Res- ervoir above Santa Barbara. Acreage irrigated at the Spanish missions was small, yet it provided an important object lesson for Amer- ican and European settlers who began arriving in California in the 1830 's and 1840 's. During the first two decades of American occupation, from 1850 to 1870, settlers in the southern part of California built small ditches diverting from streams of the coastal plain, mainly in the San Gabriel and Santa Ana River Basins. In the northern and central parts of the State water was also diverted from streams or obtained from artesian flows, and to a limited extent was pumped from streams with steam-driven pumps. In the Sierra Nevada foothills water was acquired from mining ditches, irrigation being accelerated by the expansion in population that accompanied and fol- lowed the Gold Rush. The first irrigation was from nearby streams, with- out storage, and lands irrigated were limited to those that could be watered from low summer flows. In the southern part of California, however, the need for storage reservoirs was early recognized, and several important dams, including Bear Valley, Hemet, Sweetwater, and Cuyamaca, were constructed or be- gun in the 1880 's. In the remainder of the State all major storage reservoirs primarily for irrigation have been provided since 1900. A number of these, such as Melones, Don Pedro, and Exchequer, were made fea- sible by the hydroelectric power to be developed with the water stored. Early irrigators following Spanish and Mexican days were mainly individuals. By 1856, however, a "commercial" company had constructed canals to irrigate wheat near Woodland in Yolo County, and about that time groups of settlers were joining to- gether to build ditches in the south. Construction of larger irrigation works by development companies and cooperatives was well under way by the 1870's INTRODUCTION 23 and 1880's, both in the southern part of the State and in the central and southern parts of the San Joaquin Valley. In 1887 the original Wright Irrigation Dis- trict Act was passed by the Legislature, partly as a result of prior court decisions regarding water rights which were adverse to irrigation development. By fol- lowing the general pattern of this act, the principal irrigation expansion in California has been accom- plished during the past 30 or 40 years. Owing largely to authority granted by the Legislature to irrigation and similar districts to finance, construct, and oper- ate irrigation works, and also because of the activi- ties of many individuals, cooperatives, and water utilities, irrigated agriculture has attained its pres- ent position of dominant importance to the economy of the State. The locations of all irrigation and water storage districts, the more important of the many types of public districts responsible for development of irrigation water in California, are shown on Plate 3, "Irrigation and Water Storage Districts. " The continuing increase in use of water for irriga- tion in California is indicated in the following tabu- lation showing historical growth of the area devoted to irrigated agriculture : Year Area irrigated, in acres Source of information 1880 Less than 400,000 1,004,233 1,446,114 1,708,720 3,188,541 v 4,219,040 3,540,350 4,276,554 6,438,324 6,850,000 1890 Report of State Engineer, 1880 1900 1902 1911 1919 mission 1929. __ Reports of United States Census Reports of United States Census State-wide Water Resources Investigation 1949 Present (1950) _ The ground waters of California have been ex- tensively tapped for irrigation, as well as for do- mestic and municipal uses. Improvement of pumping equipment and extension of electric power service generally over most of the important ground water basins, together with the cited growth of water re- quirements, have so stimulated development that in some of these basins the ground waters have been overdrawn. Serious losses have already resulted and more will follow unless corrective measures are taken. Underground sources furnished about half of the domestic, municipal, industrial, and irrigation water in California in 1949. Advances in the use of water in other fields have also been striking. Commercial hydroelectric power, first developed in California in 1893, constitutes ap- proximately half of the presently installed power ca- pacity in the State. Water supplies for municipali- ties, initially secured locally, are now in some cases being brought great distances. Outstanding illustra- tions are the aqueducts importing Sierra Nevada water to San Francisco and its environs, to the East Bay cities, and to Los Angeles, and the conduit bringing Colorado River water to Los Angeles and the other communities constituting the Metropolitan Water District of Southern California. During the last 20 years federal agencies have en- tered the field of water resource development in Cali- fornia in a large way in the financing and construc- tion of projects for water conservation, irrigation, navigation, and flood control, and for the protection of wildlife. Both the Corps of Engineers of the United States Army and the Bureau of Reclamation of the Department of the Interior have outlined compre- hensive proposals, some of which have been author- ized, with construction of several under way. The most extensive federal project now under construc- tion is the Central Valley Project, which is being built in substantial accord with the State Water Plan, referred to later in this chapter. Progress in the use of water in California has been made despite two incompatible doctrines governing- rights to the use of water in surface streams, those of appropriative and of riparian rights. A similar conflict has been encountered in rules applicable to ground water, between the overlying right, formulated by analogy to the riparian right, and appropriation. Recognition of pueblo rights is based on terms of the treaty with Mexico when Alta California was ac- quired by the United States, but such rights are now exercised only by the Cities of Los Angeles and San Diego. The appropriative doctrine in its generally accepted form originated in this State in the early mining cus- toms. These were recognized by the courts, but the earliest statute sanctioning this doctrine was enacted on March 21, 1872. (Cal. Civ. Code, Sees. 1410-1422.) Prior to December 19, 1914, an appropriative water right could be established in California either by actual diversion and application of the water to bene- ficial use, or by posting a notice at the point of di- version and recording the notice with the county re- corder, followed by diligence in construction and ap- plication of the water to beneficial use. Since that date an appropriative right to water, other than per- colating ground water, must be initiated by filing an application with the Division of Water Resources of the State Department of Public Works, pursuant to Divisions 1 and 2 of the State Water Code (formerly the Water Commission Act). In contrast with either a riparian right to surface water or an overlying right to ground water, an appropriative right is created by use and is lost by nonuse. The opposing riparian doctrine as now established in California consists of the old common law rule, as modified by California court decisions, and particu- larly by Section 3 of Article XIV of the State Con- 24 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA stitution adopted in 1928, and decisions following and applying it. Under this doctrine, a riparian land- owner is entitled to a reasonable use of water correla- tive with all other riparian owners bordering on the same stream, lake, or watercourse, except that all the water may be consumed by an upper riparian owner if necessary for domestic use. The State Supreme Court, in a line of decisions between 1886, Lux v. Haggin, and 1927, Herminghaus v. Southern Cali- fornia Edison Co., vacillated between strict applica- tion and liberalization of the old common law rule. The harsh construction of the rule in the latter case brought about a general demand for modification. The result was adoption of the constitutional amendment of 1928. This amendment, which has repeatedly been upheld by the courts of the State, imposed reasonable and beneficial use on riparian as well as on other water users. It provides as follows : "Sec. 3. It is hereby declared that because of the conditions prevailing in this State the general wel- fare requires that the water resources of the State be put to beneficial use to the fullest extent of which they are capable, and that the waste or un- reasonable use or unreasonable method of use of water be prevented, and that the conservation of such waters is to be exercised with a view to the reasonable and beneficial use thereof in the interest of the people and for the public welfare. "The right to water or to the use or flow of water in or from any natural stream or water course in this State is and shall be limited to such water as shall be reasonably required for the bene- ficial use to be served, and such right does not and shall not extend to the waste or unreasonable use or unreasonable method of diversion of water. Riparian rights in a stream or water course attach to, but to no more than so much of the flow thereof as may be required or used consistently with this section, for the purposes for which such lands are, or may be made adaptable, in view of such reason- able and beneficial uses ; provided, however, that nothing herein contained shall be construed as de- priving any riparian owner of the reasonable use of water of the stream to which his land is riparian under reasonable methods of diversion and use, or of depriving any appropriator of water to which he is lawfully entitled. This section shall be self- executing, and the Legislature may also enact laws in the furtherance of the policy in this section contained." In 1935 the Supreme Court of California in the case of Peabody v. City of Vallejo, 2 Cal. 2d 351, 40 P. 2d 486 (1935), fully approved and upheld the constitutional amendment, saying in part as follows: 'The limitations and prohibitions of the consti- tutional amendment now apply to every water right and every method of diversion. Epitomized, the amendment declares : "1. The right to the use of water is limited to such water as shall be reasonably required for the beneficial use to be served. "2. Such right does not extend to the waste of water. "3. Such right does not extend to unreasonable use or unreasonable method of use or unreasonable method of diversion of water. "4. Riparian rights attach to, but to no more than so much of the flow as may be required or used consistently with this section of the Consti- tution. "The foregoing mandates are plain, they are positive, and admit of no exception. They apply to the use of all water, under whatever right the use may be enjoyed. The problem is to apply these rules in the varying circumstances of cases as they arise. ' ' The new policy of water law was given its full expression in the case of Meridian Ltd. v. City and County of San Francisco, 13 Cal. 2d 424, 90 P. 2d 537, 91 P. 2d 105 (1939), wherein, for the first time, the court held in effect that (1) title to all unappro- priated water over and above proper demands and requirements of vested rights is in the State in trust for the use and benefit of the people. It was also held that (2) it is for the State to prescribe the regula- tions pursuant to which rights to use such unappro- priated water might be acquired. Further, it was held for the first time that (3) upstream storage in and of itself for flood control and stream flow stabilization for future use is a beneficial use of water. The court directly held that (4) the declarations in the Water Commission Act (now codified in the Water Code) of ownership of all unappropriated water by the State were implicit in the 1928 constitutional amend- ment, and are to be given full force and effect. THE CALIFORNIA WATER PROBLEM The over-all water problem of California is made up of many interrelated problems, some of which are mainly local, while others are state-wide in implica- tion. Prior to the time when the southern part of California had to turn to the Colorado River, and until rapidly receding ground waters in southern San Joaquin Valley brought about initiation of the Cen- tral Valley Project, water needs were met in most instances by some form of local action. It is now generally realized, however, that a greater measure of state leadership and participation in planning and construction is required if the water resources of California are to be properly controlled, regulated, protected, and utilized to meet rapidly increasing needs of the people. INTRODUCTION 25 From a state-wide point of view, redistribution of the water supply from areas of surplus to areas of deficiency provides the greatest challenge. About two- thirds of the water is in the northern third of the State, whereas the greater requirements — agricultural, industrial, and municipal — are in the central and southern portions. The solution of such a geographical problem must involve transportation and exchange of water, generally from north to south. It must in- clude construction of surface storage reservoirs and utilization of the great ground water storage capacity of the valleys for regulating stream flow. Multiple- purpose basin and transbasin developments will be required, involving many complex technical, financial, and legal problems. There must be increased devel- opment and transmission of hydroelectric energy for project purposes and to help meet growing urban and agricultural demands for electric power. Solution of the problems of flood control involves construction of detention reservoirs, levees, channel improvements, and by-pass channels. In many situations flood con- trol and conservation works can be combined, but even where this is possible complete flood control may require additional separate works. In the Central Valley, conservation features will provide a substan- tial measure of salinity control, as well as improve- ments to navigation. On many if not most streams of the State, water conservation will contribute to rec- reation, fish, and wildlife, and other beneficial pur- poses. A century of experience in California has demon- strated that growth and development of the State depend on the adequacy and economical utilization of its water supply. The California Water Plan will fur- nish a present pattern to meet the future need. It will enable the comprehensive and coordinated con- trol, regulation, and utilization of this great and most vital resource, and will be susceptible of construction by stages as the need develops. However, as the future unfolds, as more and better information becomes avail- able, and as conditions change, planning for water resource development must continue. PREVIOUS INVESTIGATIONS The first broad investigation of the irrigation prob- lem of California was made by a board of commis- sioners on "The Irrigation of the San Joaquin, Tu- lare, and Sacramento Valleys of the State of Cali- fornia, ' ' described in a report published by the House of Representatives in 1874 as Ex. Doc. No. 290, Forty- third Congress, First Session. It outlined a hypothet- ical irrigation system for the San Joaquin, Tulare, and Sacramento Valleys. Other investigations by fed- eral and state agencies followed during the next sev- eral decades, the most noteworthy of which were by Wm. Ham. Hall, State Engineer from 1878 to 1889. His reports contain meteorological and stream flow data, with notes on irrigation, drainage, and flood control, all of which proved of great value in planning water developments in the years that followed. The most comprehensive recent investigations of the water resources of California were those by the State Engineer under authority of acts of the Legislature in 1921, 1925, and 1929. First reports of these inves- tigations were presented in Division of Engineering and Irrigation Bulletins Nos. 4, 5, and 6, and in Divi- sion of Water Resources Bulletins Nos. 9, 12, 13, 14, and 20. A report giving residts of subsequent investi- gations and outlining revised proposals was published in 1930 as Division of Water Resources Bulletin No. 25, entitled "Report to Legislature of 1931 on State Water Plan. ' ' It outlined a coordinated plan for con- servation, development, and utilization of the water resources of California. The plan was approved and adopted by the Legislature by Chapter 1185, Statutes of 1941, and designated the "State Wafer Plan." The State Water Plan was amended by Chapter 329, Statutes of 1945, which eliminated the proposed Trin- ity River Diversion. Division of Water Resources Bulletins Nos. 26, 27, 28, 29, and 31 outlined in greater detail project plans for coordinated develop- ment of the water resources of the Central Valley, and for water conservation and flood control in the Santa Ana River Basin. Bulletins Nos. 34, 35, and 36 dealt with collateral matters of water charges and costs and rates of irrigation development. Bulletin No. 31 discussed briefly the plans for diversion and trans- mission of Colorado River water to the South Coastal Basin under the project of the Metropolitan Water District of Southern California. OBJECTIVE OF STATE-WIDE WATER RESOURCES INVESTIGATION Although investigations that led to the State Water Plan were conceived as comprehensive and state-wide, they were never completed in that pattern. All phases were not considered for certain areas of the State, and important projects were omitted and left for fur- ther study. Furthermore, although adopted by the Legislature in 1941, the plan was formulated in 1930 and was based on investigations and studies conducted in the preceding decade. Since 1930 the population of California has almost doubled, and the need for flood control, water conservation, and power has more than kept pace with population and industrial growth. The objective of the current state-wide water re- sources investigation is, therefore, the preparation of The California Water Plan, a revised and more complete plan for the fullest conservation, control, protection, and utilization of the water resources of California, both surface and underground, to meet present and future water needs for all beneficial pur- poses and uses in all areas of the State, so far as is practicable. 26 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA SCOPE OF BULLETIN As has been stated, this is the second in a series of bulletins concerned with preparation of The Cali- fornia Water Plan. The first of the series, "Water Resources of California," which was released by the State Water Resources Board in 1951, comprises an inventory of the water resources of the State. This present bulletin constitutes a determination of the present use of water throughout California and a forecast of the ultimate water requirement. These two publications provide many of the basic hydrologic data and information necessary for preparation of the third bulletin, which will describe The California Water Plan. A fourth bulletin will contain a sum- mary of the earlier publications of the series. A brief and generalized description of the methods employed in estimating the present use of water and forecasting the ultimate water requirement will serve to illustrate the scope of this bulletin. In general, the estimates and forecasts were made on an areal basis; that is, determinations were made by service areas of the various types of development making beneficial use of water. Appropriate factors of unit water use were then applied to these areas in order to estimate their total water requirement. In the case of the present water requirement, areas of water-using urban and irrigated agricultural types of development, as determined from land use survey data, were multiplied by chosen factors of unit water use, and the products added to obtain the total water requirement. Data on unit use of water in metropoli- tan and urban areas were obtained generally from records furnished by water service agencies of de- liveries to representative blocks of the various types of development. Data on unit use of water for irriga- tion were obtained generally from delivery records and from the results of experiments, and were modi- fied to account for variations in climate and agricul- tural practice in the several parts of the State. Because of the importance of the three great metro- politan areas of California, in and around San Fran- cisco, Los Angeles, and San Diego, relatively detailed land use surveys and determinations of unit use of water were conducted in these areas. In the case of ultimate water requirement, the entire area of the State was considered. The inherent ca- pacity of the land to support the various types of development requiring water service was determined as follows: 1. Urban land use was projected on the basis of indicated 1 rends of growth and development, com- munications, natural resources, and other factors pertinent to a balanced economy. 2. Irrigated agriculture was projected on the basis of land classification survey data, on the assumption that all irrigable lands not presently served with water will ultimately receive a complete and adequate water supply. 3. Remaining lands of the State, neither urban in character nor given over to irrigated agriculture under ultimate conditions of development, were pro- jected on the assumption that they will support a rural population, generally sparse and widely scat- tered but requiring a water supply for sustenance. To the tiltimate pattern of land use so determined — ■ urban, irrigated agricultural, and other water service areas — appropriate factors of unit water use were ap- plied, and the products added to obtain the forecast of ultimate water requirement. The unit water use factors for irrigated agriculture were generally the same as those used in connection with the present land use pattern, but the factors for urban use were modi- fied in accordance with indicated trends. Few data were available regarding unit use of water by the types of development in remaining lands of the State, and factors of unit water use adopted were necessarily based on limited information as to present deliveries of water. Dependent upon local conditions, either all or a portion of the water served to the foregoing urban, irrigated agricultural, and other water service areas is consumed or lost to further beneficial use. However, there are other uses of water that are not necessarily consumptive in their nature, such as those for the generation of hydroelectric energy, for the propaga- tion and preservation of fish life, and for recreation. Furthermore, certain factors of demand may be im- posed upon the water by the nature of its beneficial use, such as those pertaining to specific rates, times, and places of delivery of the water, losses of water, and quality of the water. In general, these noncon- sumptive uses and demand factors incidental to water service can only be evaluated on the basis of a specific plan of water resource development. For purposes of this bulletin, therefore, they are discussed in general terms with particular regard to their effects on The California Water Plan, in which plan they will neces- sarily be given more detailed consideration. Since a principal purpose of studies leading to preparation of this bulletin was to provide informa- tion required in preparation of The California Water Plan, it was necessary to compare the present yields of water supply works with the present water require- ments. Any resulting estimates of deficiency under present conditions were then added to the difference between estimated present and utimate water require- ments in order to determine the probable ultimate supplemental water requirements. This served to es- tablish the approximate general pattern of required future regulation and conveyance of water throughout California. However, the exact pattern will be de- pendent upon the feasibility and relative costs of al- ternative works, studies of which are under way in connection with preparation of the next bulletin in this series. INTRODUCTION 27 The following chapter describes in some detail the methods and procedures used in the estimates and forecasts of water utilization and requirement. It is followed by separate chapters for each of the seven major hydrographic areas of California, in each in- stance presenting and discussing the estimates and forecasts for the respective hydrographic areas and subdivisions thereof. These chapters also contain de- scriptions of the hydrographic areas and their sub- divisions, water supply conditions and development, and land use as it relates to water utilization and re- quirement. A final chapter summarizes on a state-wide basis the material presented in earlier portions of the bulletin. Doctor David Weeks, Professor of Agricultural Economics at the University of California in Berke- ley, and an authority on agricultural economics and trends, conducted the studies reported in this bulletin dealing with the probable crop pattern in California under conditions of complete development. His paper on this subject is included as Appendix A. Appendix B comprises a list of water service agen- cies in California. Insofar as could be determined within the scope of the investigation, the list consti- tutes a complete compilation of all known public and private agencies presently supplying water for domes- tic, municipal, or irrigation purposes in the State. GENERAL CONSIDERATIONS RELATING TO WATER UTILIZATION IN CALIFORNIA The State Water Resources Act of 1945, the basic law under which this bulletin was prepared, states in part as follows: "In studying water development projects, full consideration shall be given to all beneficial uses of the State's water resources, including irrigation, generation of electric energy, municipal and indus- trial consumption of water and power, repulsion of salt water, preservation and development of fish and wildlife resources, and recreational facilties, but not excluding other beneficial uses of water, in order that recommendations may be made as to the feasibility of such projects and for the method of financing feasible projects. Fish and wildlife values, both economic and recreational, shall be given con- sideration in any flood control or water conserva- tion program." As a preface to the ensuing presentation of data and estimates, it is considered desirable to discuss in general terms certain aspects of water utilization in California in the light of the foregoing directive of the Legislature. This section, then, comprises a brief description and discussion of the major beneficial uses of water in the State, their interrelationships, their demands upon the available water resources, the in- dicated trends in such uses of water, and related factors such as costs of water. The prefatory state- ment should facilitate understanding of the subject matter of this bulletin. Water Supply It was shown in Bulletin No. 1, "Water Resources of California," that the total runoff of all streams of the State, measured as they enter valley and mesa lands, averaged nearly 71,000,000 acre-feet per season over the 53-year mean period from 1894-95 through 1946-47. In addition, precipitation in the mean sea- sonal amount of over 32,000,000 acre-feet fell on valley and mesa lands during the 50-year period from 1897-98 through 1946-47, of which a portion was available to meet demands on the water resources of the State. When the available water resource is com- pared with the estimated present total mean seasonal water requirement of the State of about 25,000,000 acre-feet, measured in terms of consumptive use of applied water plus irrecoverable losses, and the fore- cast ultimate requirement of about 51,000,000 acre- feet, as presented later in this bulletin, this water resource might seem to be generously ample. How- ever, as regards both location and time of occurrence, the fresh waters of California are not well related to the demands put upon them. For these reasons, it is probable that they will be only partially conserved and put to beneficial use even under conditions of ultimate development. Nearly 28,900,000 acre-feet, or about 41 per cent of the total mean seasonal runoff of California, occurs in the North Coastal Area, and about 22,400,000 acre- feet, or nearly 32 per cent of the State's total, in the Sacramento River Basin of the Central Valley Area. Thus, over 72 per cent of the runoff occurs north of a line drawn roughly through Sacramento. In unfor- tunate contrast, an estimated 77 per cent of the present water requirement of the State occurs south of the same line, which value is expected to expand to about 80 per cent under conditions of ultimate devel- opment. From this it is apparent that solution to the basic water problem of California must involve the transportation of substantial amounts of water from north to south. Both precipitation and runoff in California vary widely in their occurrence within the season and from season to season. Generally, precipitation is con- fined to winter months, and summers are extremely dry. The amount of flow in streams follows closely the occurrence of precipitation, and in many streams the flow dwindles to nothing in summer and fall. This characteristic of runoff is modified somewhat in streams of the Sierra Nevada, wherein high stream flow may be sustained well into summer by the stor- age effect of heavy snowpack in the mountains. Aside from monthly variation in her natural water supply, California is subject to wet and dry periods 28 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA A during which average precipitation and runoff depart far from the mean. The periods may extend for many years. One of the most severe dry periods in most of the State extended from 1928 through 1934. A severe drought was experienced in the southern part of Cali- fornia from 1895 through 1904. More recently, and following a very wet period from 1938 through 1944, the State suffered dry seasons from 1945 until 1952, which latter season was exceptionally wet. Generally in California the seasons of 1923-24 and 1930-31 were the driest of record. In 1923-24 the estimated total runoff to valley and mesa lands was only about 18,300,000 acre-feet. Maximum seasonal runoff during the period of record occurred in 1937-38 and is esti- mated to have been about 135,000,000 acre-feet. During the critical 10 years from 1927-28 through 1936-37, average seasonal runoff was 69 per cent of the 53-year mean, and during each season of that drought period runoff was less than the mean. Severe and damaging floods are another symptom of the erratic occurrence of California's water re- sources. Ever since the first settlements on flat lands along the banks of streams, periodic floods have en- dangered life and property. Most floods of the State are of two general types, with quite different char- acteristics. Rainwater floods occur in winter months and are caused by protracted general storms affecting wide areas. On rare occasions peak discharges of such floods are extremely high, but the flood duration is short, usually no more than a few days. Snow floods, resulting from rapid melting of the snowpack, occur in streams that drain the higher mountains of the State, principally the Sierra Nevada. Characteristi- cally, such floods occur during months from April through July, and have much longer duration and lower peak flow than rainwater floods. Maldistribution of the water resources of Cali- fornia, as regards both place and time of occurrence, has made necessary the construction and operation of numerous works to control and regulate the flow of streams, convey the conserved water to areas of use, and distribute it therein. California has long been a leader in the development of outstanding hydraulic works, a major portion of which have been financed, constructed, and operated by local public and private agencies. If the State is to realize her full potential, additional works of even more imposing size and scope must be achieved to control, regulate, dis- tribute, and permit the required utilization of her bountiful water resources. The extensive ground water basins of California provide natural regulation for runoff from tributary drainage areas and for precipitation directly on the overlying lands. As has been stated, more than half of the water presently used on irrigated lands and Eor domestic, municipal, and industrial purposes in Hi" State is regulated in ground water basins. Addi- tional natural regulation would be provided if pres- ently unused ground water storage capacity were utilized to the full extent of possible safe yield of the basins. Furthermore, as additional surface water sup- plies are developed and made available for storage in ground water basins, safe yield of the underground reservoirs will be increased. Under ultimate develop- ment the maximum amount of water could be made available on demand through operation of surface res- ervoirs in conjunction with cyclic underground stor- age. Such coordinated operation would necessitate an adequate supply of energy to pump ground water in a series of dry years. The extent of the valley fill areas of California is indicated on Plate 4, "Valley Fill Areas." Many of these are known ground water basins, whereas the susceptibility of some to ground water storage remains to be established. Most fresh waters in California are of excellent quality and well suited to irrigation and other bene- ficial uses. This is especially true of drainage from the North Coastal Area and from the eastern side of the Central Valley Area, both of which areas have large watersheds with high water yield. Analyses show that their surface and underground waters pos- sess remarkably slight concentrations of salts, low per cent sodium, and relatively small amounts of ele- mental boron. These waters are of the bicarbonate type, and calcium is the predominating base. Surface waters of comparatively high salinity are found in streams on the west side of the San Joaquin Valley, in Cache Creek in the Sacramento Valley, in basins on the west slope of the Diablo Range that separates the Central Coastal and Central Valley Areas, in Cuyama and Santa Maria Rivers in the Central Coastal Area, and in Pirn and Sespe Creeks in the South Coastal Area. Mineral solubles in these waters include significant amounts of boron, and relatively high concentrations of sulphates or chlorides. Ground waters receiving replenishment from such inferior surface waters have similar chemical characteristics. Gradations in the quality of fresh water supplies of California are mainly correlated with climate, soil, and geologic complex. Any significant variation in chemical properties not correlated with these natural factors is usually caused by pollution or contamina- tion from foreign sources. These may include indus- trial wastes and sewage, unconsumed irrigation water, or imported water of inferior quality. Depreciation in qiiality of ground water may also result from infil- tration of sea water along the coastal strip, from de- fective wells, and from lack of salt balance due to inadequate ground water outflow. ' Irrigation Most of the arable lands of California are situated in regions classified climaticall.v as arid or semiarid, where rainfall is generally insufficient to support the growth of perennial crops. For this reason, and be- cause of the characteristically long rainless summers INTRODUCTION 29 even in well-watered regions of the State, irrigation is extensively resorted to in order to make agricul- tural enterprises possible or more profitable. For many years California has led all states of the Union in irrigated agriculture, and, as has been stated, some 7,000,000 acres within the State are served with irrigation water. This constitutes by far the greatest single demand on the developed water supplies of California, and about 90 per cent of the water bene- ficially used in the State is utilized by irrigated agri- culture. Agricultural crops utilize varying amounts of the rain that falls upon them. Certain perennial crops, such as alfalfa and irrigated pasture, continue to grow throughout the winter rainy season in most parts of California, and consume a portion of the precipitation to sustain this growth. On other agricul- tural lands where crops are not grown in winter there is some consumption of winter rainfall by evapora- tion from the bare land and by the growth of weeds and native grasses. Of the precipitation that perco- lates into the soil, a part may remain within the root zone of the plants for a considerable time and sus- tain their growth until exhausted. However, as has been stated, precipitation available to crops is not generally sufficient in California to meet their re- quirements throughout the summer. This deficiency can only be remedied by the application of irrigation water from developed sources. Monthly irrigation de- mands vary considerably, depending upon the type of crop, climate, and agricultural practice. On the average, little irrigation water is applied in winter months, and peak summer monthly demands may be as large as 25 per cent of the seasonal total. •/Ordinarily, a substantial portion of the irrigation water applied to his fields by a farmer is consump- tively used by transpiration from the vegetative growth and by evaporation. However, the remainder of the applied water either percolates below the root zone of the crop or drains away on the surface, or both. The ratio of consumptive use of the applied irrigation water to the total amount of such applied water is termed "irrigation efficiency" and is em- ployed as a rough measure of the relative efficiency of irrigation practices. Irrigation efficiency varies widely throughout California, depending on one or more of many factors, including the type of crop, topography, porosity of soil and subsoil, salinity of soil and water, method of irrigation, availability of water, and cost of water. In areas of deficient water supply and high cost of water the tendency has been to restrict crops to those requiring a minimum amount of water. In certain parts of the South Coastal Area where such condi- tions prevail, farmers have restricted their application of irrigation water to less than the optimum amount which the plants could consume. This subnormal ir- rigation may have resulted in high irrigation efficien- cies, but probably has reduced crop production in some cases. In parts of the Sacramento Valley water is rela- tively cheap and plentiful, and low irrigation efficien- cies are common. Similar conditions usually hold in the Imperial Valley, but in this valley there is an urgent demand for excess irrigation water to flush detrimental salts from the soil. Generally throughout California irrigation efficiency probably averages be- tween 50 and 60 per cent. Since more water is applied for irrigation than is actually consumed by the plants, an opportunity ex- ists for saving of water through its more careful ap- plication. In this connection a recent quotation by Dr. Frank J. Veihmeyer, former Chairman of the Irriga- tion Department of the College of Agriculture, Uni- versity of California, is pertinent : ' ' Deterioration of land due to wasteful use of water is prominent throughout the world. The belief that for the best condition of plants the soil should be kept wet is not founded on fact. You do not increase growth by maintaining large amounts of water in the soil. You can save water by reducing the num- ber of applications. The irrigated area of California could almost be doubled, if waste could be avoided. ' ' Careful application of irrigation water is infrequently obtained except in periods of drought emergency. In certain past studies of proposed irrigation works in the State it has been assumed that irrigated lands can withstand a deficiency of 35 per cent of the average seasonal requirement in seasons of critically deficient water supply, provided that these deficiencies do not occur frequently and in no case in consecutive seasons. This assumption is based on experience throughout California. In actual operation of several large irri- gation systems, deficiencies of as large as 50 per cent of the requirement occurred in such extremely dry seasons as 1924 and 1931. In these instances perma- nent crops suffered no lasting damage. In addition to losses of water inherent in its field application, in any water supply and distribution system a portion of the available water is lost by seep- age and evaporation from reservoirs, leakage from conduits, seepage from canals, etc. The amount of these losses varies over wide limits. The principal factors affecting reservoir losses are the climate, per- meability of the materials underlying the reservoir, area-depth relationship of the reservoirs, and design and maintenance of the impounding structures. Evap- oration losses from reservoir surfaces average from three to four feet of depth per season in California, but may be as high as six or seven feet in dry, hot, windswept localities. Conveyance losses of water are generally dependent upon design and maintenance of the system, which in turn are largely influenced by economic considerations. In well-constructed and ad- equately maintained, closed-type conduits they may be negligible. In open, unlined ditch systems they may 30 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA run higher than 50 per cent of the diverted water supply. Depending- upon soil and geologic conditions, a portion of storage and conveyance losses may be salvaged for re-use. However, in many instances water lost in such fashion creates high water table condi- tions, damaging to crop lands. Since 1940 there has been a marked acceleration in the placing of new lands under irrigation in Cali- fornia. This has been caused by increased require- ments for agricultural produce brought on by World War II, by similar demands of the rapidly growing population of the State, and by sustained high farm prices. How long the present rate of growth of irri- gated agriculture will continue is problematical. How- ever, the eventual need for a very high degree of de- velopment of the irrigable lands of California seems assured. In studies for this bulletin it was assumed that under conditions of ultimate development all lands suitable for irrigated agriculture will be irri- gated. It is realized that this complete irrigation de- velopment may not actually occur, and that in some areas it may always be more profitable to grow dry- farmed rather than irrigated crops on lands classi- fied as irrigable. However, the assumption is conser- vative in the sense that it results in an estimate of maximum probable requirement for water. With this in mind, any lesser future requirement will be pro- vided for in allocation of the available water resources of the State. Urban Use of Water The people living in the urban centers of California and the commerce and industry that serve and support them create a demand on the developed water supplies second only to that of irrigated agriculture. In meet- ing this requirement local public agencies of the great metropolitan areas of the State have constructed monumental engineering works exemplified by the Hetch Hetchy, Mokelumne River, Owens Valley, and Colorado River Aqueducts. Other urban communities of the State are served with municipal types of water supply from many sources, by both publicly and pri- vately owned utilities. Just as irrigated lands utilize precipitation, urban areas consume a portion of the rain that falls upon them. Home gardens, lawns, and parks are similar to irrigated crops in this respect, and there is also appre- ciable consumption of rainfall by evaporation from impervious areas, such as roofs, walks, and streets. In addition, urban areas consume portions of the water supplies delivered to them from artificial sources. The monthly urban demand on such water supply sources differs from that for irrigation because it is more uniform throughout the year, the use of water for domestic, commercial, and industrial purposes being relatively constant. On the average, monthly urban demands for water in the winter vary from 5 to 6 per cent of the seasonal total, while monthly summer de- mands vary from 10 to 15 per cent of this total. Of the several classes of water use comprising the urban requirement, that of the commercial type of development may be the greatest on the basis of unit area, but the areal extent of commercial enterprise is usually less than five per cent of the whole community. Industrial requirements vary between wide limits from industry to industry, and even within industries of the same type. Industrial use of water in the metro- politan type of community in California is usually a substantial part of the total requirement, and varies from about 10 per cent to more than a third of the total. However, the various classes of residential use normally comprise the greatest single demand on urban water supplies. The water supplied to meet urban requirements is not all consumptively used. Portions may run off on the surface or percolate to underlying ground water basins. A substantial portion is discharged to the sewers, and, depending upon the means of sewage dis- posal and its mineral and bacteriological quality, may or may not become available for re-use. The amount of sewage from urban communities in California varies from about 25 to 75 per cent of the amount of water delivered to them, and probably averages about 50 per cent throughout the State. Reclamation of water from sewage as a source of water supply is accom- plished in many interior communities incidental to return of the water to ground water basins or stream channels. Construction of works for sewage rec- lamation is receiving consideration in several coastal communities with present water shortages, and may become a more important part of water conservation development in the future. In studies being made in connection with prepara- tion of The California AVater Plan, it is being assumed that no deficiency in urban water supply will be per- mitted, and that the requirement will be fully met at all times. This is a most conservative assumption, for it has been frequently demonstrated in California that in times of drought emergency it is possible to de- crease urban water use very materially without undue hardship. This has been accomplished by enforced rationing and by educational campaigns to avoid un- necessary waste. In one community, as a result of serious shortage in water supply caused by a series of exceptionally dry years, the amount of water delivered in 1948 was reduced 26.3 per cent below that delivered in 1947. This was accomplished by enforced rationing and education. In another city the use of water was reduced from 64 million gallons on one day to 38.5 million gallons on the ensuing day by means of a newspaper and radio educational campaign. Historically, the population growth of California lias been rapid but intermittent. Certain communities have nearly doubled their population each decade INTRODUCTION 31 since 1900, and throughout the State the population increased 53 per cent from 1940 to 1950. Perhaps the most significant recent trend in urban growth in Cali- fornia is toward decentralization of residential and commercial types of development in fringe areas around the existing communities. In studies for this bulletin, probable ultimate urban use of water was forecast generally on the assumption of an ultimate population approximately four times as great as at the present. This ratio was based on results of detailed studies of complete land use and of population satura- tion in the San Francisco Bay, Los Angeles, and San Diego metropolitan areas. It is believed to be reason- ably conservative in the aggregate, although probably subject to wide error in particular instances. Hydroelectric Power A large and important nonconsumptive demand on the water resources of California is that imposed by use of water for generation of hydroelectric energy. Of recent years the requirement for electric power has increased even more rapidly than population. The total amount of power generated for use in Cali- fornia in 1940 was a little over 13 billion kilowatt- hours, of which about 3.3 billion were from plants located on the Colorado River outside of the State. In 1950 the total was more than 29.6 billion kilowatt- hours, an increase of some 127 per cent. Of the total, about 4.8 billion kilowatt-hours came from Colorado River plants. Locations of the principal power in- stallations of the State, both hydroelectric and fuel- electric, transmission lines, and substations, are shown on Plate 5, "Electric Power Development, 1954." In order to meet the rapidly "rowing requirement for electric power it has been necessary for electric utilities in California to increase their capacity ma- terially, particularly since "World War II. For various reasons, principally economic in nature, the greater part of this increase has been made by construction of fuel-electric plants rather than hydroelectric. How- ever, even today the total installed capacity of hydro- electric power plants in California is approximately one-half that of the total of all types of electric power generating plants. In 1940 the installed capacity of all electric plants within the State totaled about 2,720,- 000 kilowatts, of which approximately 1,540,000 kilo- watts were hydroelectric installations and the remain- der fuel. In 1950 the total installed capacity was about 5,320,000 kilowatts, of which approximately 2,600,000 kilowatts were hydroelectric. It is believed to be reasonably safe to assume that with probable continued rapid population and industrial growth of California, and with the demonstrated trend for even more rapid increase in requirement for electric power, a demand will exist in the future for all hydroelectric power that can be obtained from further development of the water resources of the State. In order to be capable of producing large amounts of firm energy, that is, energy available on demand, a hydroelectric power plant requires an abundant, nearly uniform supply of water located at high eleva- tions to provide large potential fall. These desirable conditions occur only in rare instances in California. Although relatively large watersheds have sufficient elevation to provide substantial fall, many such areas, particularly in the southern part of the State, have so limited or intermittent a water supply that devel- opment of hydroelectric power is impracticable. In the Sierra Nevada, and more particularly in the north- ern Sierra, topography and water supply conditions are more nearly ideal for hydroelectric energy genera- tion. By far the greatest development of hydroelectric power in California has been in the Sierra Nevada, and present development is continuing in this area. In the northwestern portion of the State the water supply is ample but the topographic relief is not as great as in the Sierra, and a relatively large part of the water originates at low elevations. Nevertheless, the potential for hydroelectric power development in the Nortli Coastal Area is very large. Only minor installations have been constructed in this area to date. Because of the characteristic seasonal nature of the water supply throughout California, regulatory storage is almost always necessary for the production of firm energy throughout the year. Due to the ex- treme variation in flow of most streams, it is usually necessary to generate large amounts of secondary energy in order to utilize the development to its eco- nomic potential. This makes desirable the full coordi- nation of power generation from hydroelectric sources with that from fuel-electric sources. The demands on the water supply for power purposes coincide only in part with those for other beneficial uses of the water, such as irrigation, and can be only partly coordinated with them. To offset the effects of this incompatibility, revenues from the sale of hydro- electric power from multipurpose projects have served in many instances to make irrigation and other fea- tures of the projects financially feasible. Without consideration of economic or engineering feasibility, or of conflicts with other demands on the water supply, it is estimated on a theoretical basis that the presently developed and potential undevel- oped hydroelectric power capacity within California is of the order of 10,700,000 kilowatts. Approximately 4.000,000 kilowatts of this capacity occurs in streams of the Sacramento Valley, 3,200,000 kilowatts in those of the San Joaquin Valley, and 600,000 kilowatts in the Lahontan and Colorado Desert Areas, while the remaining capacity, some 2,900,000 kilowatts, occurs in the North Coastal Area. Only minor possibilities for future hydroelectric power installations exist elsewhere in the State. 32 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Timber and Minerals The natural resources of California support an im- portant group of basic industries, of which oil and gas, timber, and the mining industries occupy the more prominent positions. Significant use of water by the oil and gas industry is confined to refining and processing, and is considered in this bulletin along with urban requirements. Use of water by the timber and mining industries is an item of importance in local areas in which the industries are located, al- though the total use for this purpose is minor in com- parison with other consumptive uses of water in the State. The locations of principal timber lands and auriferous gravel deposits are shown on Plate 6, ; ' Timber Lands and Auriferous Gravel Deposits. ' ' Data for this plate were furnished by the United States Forest Service and the State Division of Mines. Commercial stands of timber are found principally in the mountainous parts of the North Coastal Area and above 3,000 feet on the westerly slopes of the Sierra Nevada in the Central Valley Area. Less im- portant stands of commercial timber occur along the easterly slope of the Coast Range in the Central Val- ley Area, in Santa Cruz and San Mateo Counties, and in the Lahontan Area between Mono and Lassen Coun- ties. A few comparatively small stands of timber are located in the southerly part of the State. The timber cut in California amounted to about 5.7 billion board feet, International Scale, in 1952. The estimated requirements for production of lumber and timber by-products are about 56,000 gallons of water per 1,000 board feet for pulp production, 2,300 gallons per 1,000 board feet for fiberboard, and 1,000 gallons per 1,000 board feet for lumber products. On this basis the consumptive use of water in the timber industry in 1952 was about 311,000 acre-feet. The present growth on some 16,000,000 acres of timber lands susceptible of commercial development in California is estimated to be about 1,200,000,000 board feet per year. It is forecast that, under ultimate conditions and with adequate crop management, an annual yield of 3,800,000,000 board feet is possible. The water requirement for processing this sustained timber yield will be about 232,000 acre-feet per year. Discovery of gold at Coloma by James W. Marshall in 1848 caused the initial influx of white men which Led to permanent settlement and development of Cali- fornia. The present large mining industry, which in- cludes the extraction and processing of numerous valuable metallic and nonmetallic minerals, including sand, gravel, and building stone, has grown from the meager beginning at Coloma. Among the valuable minerals found in this State, gold has always occupied a principal place in the imagination of mankind, and the profusion in distribution of gold has maintained it in a leading position in California's mining indus- try. .Much of California's gold production results from the mining of placer deposits, where gold is found in nugget or granular form. Gold is extracted from placer deposits, also known as auriferous gravels, by hydraulic methods, including the washing of gravels from hillsides by the use of jetted streams of water under high pressure and by dredging. The production of gold in California in 1952 was about 258,000 ounces, much of it from the gravel de- posits. Available estimates of the water required for production by hydraidic methods range from 1.25 to 1.5 acre-feet per ounce of gold. Very little of this water is used consumptively, the greater portion being returned to stream channels where it is available for re-use. Past methods of operation in hydraulic mining areas have resulted in the discharge of large quantities of mining debris, consisting of sand, gravel, soil, and vegetable matter, into the stream channels in placer areas, and the deposition of sand and gravel waste in dredging areas. The California Debris Commission has constructed several dams for the sole purpose of re- taining placer waste and preventing such material from adversely affecting productive valley floor agri- cultural lands. Space in reservoirs constructed for other purposes has also been made available for debris collection through mutual arrangements between mine operators and the agencies controlling the reservoir areas. The restrictions now placed on hydraulic min- ing and dredging to prevent stream pollution and destruction of land indicate that in the future gold will be produced by less destructive methods and that smaller amounts of water will be required. Reduction, concentration, and refining of ores re- quire a relatively small consumptive use of water in relation to the volume of the final product. The dif- ferent processes used require varying amounts of water, but the total requirement, most of which is returned to stream chanels and underground basins and is available for re-use, is relatively minor. Much usage of this nature, particularly the requirement for final refining, is combined with general industrial re- quirements in urban and suburban water service areas. Recreation and Fish and Wildlife By virtue of her climatic advantages and wide variety of natural attractions, California enjoys an outdoor recreational opportunity of significant im- portance to her growth and economy. With antici- pated continued growth in population of the State, it is expected that the public demand for preservation and enhancement of recreational facilities will be suf- ficient to assure the provision of water supplies nec- essary for such purposes. The principal recreational facilities of the State are indicated on Plate 7, "Rec- reational Areas." In the aggregate the amount of water used for do- mestic and service facilities in recreational areas of California is relatively small, and the demands are INTRODUCTION 33 widely scattered. As for waters employed for boating, sailing, swimming, and other water sports, most are available naturally or as a result of works constructed and operated for other purposes, and the noncon- sumptive recreational use of the water is incidental to other uses. The flow of streams and the water in lakes and ponds that enhance the esthetic value of recrea- tional areas rarely have been supplied primarily for recreational purposes. In only a few instances, prin- cipally in national parks and monuments, have such recreational water requirements been considered equal or superior to those for other beneficial pur- poses. Among the many uses of water for recrea- tional purposes in California, those associated with the preservation and propagation of fish and wildlife are probably the most substantial. In this connection, certain species of fish propagated in fresh-water streams of the State support an important offshore commercial fishery. The principal present consumptive use of water in California related to fish and wildlife is the water utilized to maintain ponds and feeding areas for migratory wild fowl. Data collected in connection with the current investigation indicate that about 100.000 acres of fresh-water ponds for wild fowl are pres- ently maintained throughout the State. The seasonal delivery of water to these ponds totals some 400,000 acre-feet, most of which is consumptively used. The wild fowl ponds are included in state and federal waterfowl refuge and management areas, and in commercial and private gun clubs. They are located principally in the Central Valley Area, although some are scattered throughout the State. In addition to the ponds, a nearly equal area of adjacent land is irrigated and cropped to feed migratory waterfowl, with a requirement for water nearly as great as for the ponds. Both the United States Fish and Wildlife Service and the California Department of Fish and Game foresee the future provision of additional facilities for migratory wild fowl. Based largely on studies by these agencies, it is indicated that some 190,000 acres will eventually be used for wild fowl ponds, with a seasonal application of water of nearly 650,000 acre- feet. With regard to future use of land and water for this purpose, the following is quoted from a recent statement of the Department of Fish and Game : "It is in the needs of water for waterfowl and other game species requiring wet lands for their existence that man's agricultural and economic water needs have made the greatest inroads. Vast acreages of former marsh or semi-marsh lands have been drained for farming or other purposes, push- ing these species into a small existing area which in turn is further subject to demands for more land and more water. Waterfowl are vitally dependent on free water over productive land areas. Their con- tinued existence depends on planned reservation of water for their use. Other minor aquatic wildlife species, such as shorebirds, muskrat, beaver, etc., will benefit from any planning for waterfowl. "In order to allocate water for these species, such allocation must be done for specific areas of the State, since waterfowl have definite habits and needs for certain types of lands and feeds which cannot be met with alternate situations. In other words, wintering grounds for waterfowl must be met in warm valley areas capable of growing good reliable foods. They cannot be met on mountain areas, or on areas of poor winter climate or inferior soil. Farming development has taken over the vast majority of lands formerly available to these spe- cies; the needs found below are allocated to lands that remain available in some measure for water- fowl. Provision must be made with as much speed as possible to see that not only lands, but water for these lands are devoted to waterfowl. "That California has in this matter an obliga- tion not only to her sister States of the Pacific Waterfowl Flyway, but to our neighboring Nations to the North and South, has been brought out by many waterfowl authorities. This State has been the traditional wintering ground for vast numbers of birds of the Pacific Flyway. It has assumed this position of responsibility to the birds, if such it may be called, by virtue of its valley areas and their attendant winter climates. There is no substi- tute which will serve if these birds are to survive." As in the case of water sports, few artificial lakes are utilized exclusively for fishlife in California, such use normally being incidental to the primary pur- poses for which the reservoirs were constructed. From some reservoirs, however, releases are made to maintain downstream flow conditions favorable to the preservation and propagation of fishlife. It is con- sidered probable that in the future more reservoir storage capacity will be allocated to this purpose, and that some reservoirs will be constructed primarily to augment naturally low summer and fall stream flows in the interest of fishing. Water released down a stream to maintain the minimum flow required for fishlife does not consti- tute a consumptive use of the water. The demands of fishlife, however, are frequently incompatible with hydroelectric power development and diversion for other beneficial iises of the water. Furthermore, in coastal streams of California, the migrations of anadromous fish such as steelhead, salmon, and striped bass can only be maintained by outflow of fresh water to the ocean in substantial amounts. Resolution of the inherent conflicts between the inter- ests of stream fishing, and those of domestic, irriga- tion, hydroelectric power, and other requirements for water, is a problem for the future. It is believed that _■ iiiisnl 34 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA in many instances fishing must give way to the higher uses of water. However, an improved stream fishery can be developed and maintained by the dedi- cation of certain streams, and certain reaches of other streams, to recreation and fishing, and by the construction of upstream storage to improve low stream flow conditions. In addition, reservoirs con- structed to regulate stream flow for other purposes will provide a greatly increased lake fishery. Repulsion of Sea Water Insofar as the surface water resources of Cali- fornia are concerned, the repulsion of sea water has been a serious problem only in the delta of the Sacra- mento and San Joaquin Rivers. The low delta lands, reclaimed and protected by levees, are irrigated with water from adjacent fresh-water channels and sloughs. They include more than 350,000 acres of the most fertile and productive agricultural lands in the State. In the past, during years of low stream flow, and most notably in 1924 and 1931, saline water from upper San Francisco Bay moved far into the delta channels under the influence of tidal action. These saline invasions caused extensive damage to crops and farm lands, and resulted in marked depreciation of land values. After intensive study by the Division of Water Resources and others, it was concluded that control and prevention of the sea-water invasion could be most economically effected by repelling the saline water with fresh water released from upstream reservoirs. This was provided for in plans for the Central Valley Project. Operation of Shasta Reser- voir started in 1941, and since then there has been no significant invasion of sea water into the Sacramento- San Joaquin Delta. Originally it was estimated that minimum outflows of about 3,300 second-feet would have to be maintained in the Delta to repel sea water. This estimate has since been increased to about 4,500 second-feet, of which 3,300 second-feet is measured inflow, and the remainder is unmeasured accretions in the Delta. Tins demand on the developed water supply is largely coordinated with reservoir releases for navigation, hydroelectric energy production, and other beneficial uses of the water. So far as the ground water resources of California are concerned, the repulsion of sea water is a serious problem in many economically important ground water basins adjacent to the coast. Characteristically, these coastal basins are capped with impervious strata for soi listance inshore, and the underlying con- fining aquifers connect with the ocean. The water in the aquifers moves under pressure caused by the dif- ference in head lief ween inland intake areas and areas of discharge from the aquifers. As a resull of pump- ing from the aquifers, the hydraulic gradient, or ele- vation of the pressure head, may be lowered below sea Level, This induces landward How of sea water in the aquifers and saline degradation of the water sup- ply. Heavily pumped ground water basins in the San Francisco Bay, Central Coastal, and South Coastal Areas have experienced such sea-water intrusion, which has forced abandonment of wells, and in some instances threatens permanent damage to the basins. Other coastal basins are susceptible to similar damage if pumping increases. Experiments and studies have recently been con- ducted under direction of the State Water Resources Board to determine feasible methods of preventing sea-water intrusion of ground water basins. The ex- periments included the creation of a fresh-water mound in the confined aquifers, adjacent and parallel to the coast, by injection of fresh water in wells. The- installation of various types of impervious membranes or dikes was also studied. In general, sea-water in- trusion of ground water basins is a symptom of over- draft on the aquifers. In most cases the solution of the problem will probably involve the reduction of pumping draft on the aquifers, and the provision of a supplemental water supply from some other source. Basically, this solution is similar to that presently em- ployed for surface waters of the Sacramento-San Joaquin Delta, that is, it involves repulsion of the sea water by fresh water. Flood Control Destruction and havoc caused by floods in Califor- nia have frequently been accompanied by the eco- nomic anomaly of wastage of huge amounts of water into the ocean in areas of deficient water supply. Storage of such flood waters in upstream reservoirs would have accomplished the dual purpose of conser- vation of needed water and reduction of flood dam- ages. However, storage capacity sufficient to contain all flood waters would require extremely large and expensive reservoirs. Generally in the past it has not been feasible to attain complete conservation and flood control by storage. Improvement of stream chan- nels to provide capacities sufficient to contain peak flood flows, either separately or in combination with upstream storage, has usually provided the most economic solution to the problem of flood control in California. The construction of works to control Hoods and re- duce flood damage has been diligently pursued since the early days of California's statehood in the 1850's. One notable achievement is the Sacramento River Flood Control Project. This consists of an extensive system of leveed channels, by-passes, and drainage pumps, to protect the fertile lands and cities of the Sacramento Valley. The project is operated by the State of California, and construction expenditures to elate have totaled about $136,000,000. The funds have been provided nearly equally by local, state, and fed- eral agencies. Another example of major importance is the flood control project in Los Angeles County. INTRODUCTION 35 This is a complex system of debris basins, detention reservoirs, and improved channels to protect the tre- mendous urban development in and around Los An- geles, and is only partially completed at this time. Expenditures to date are more than $225,000,000, and the funds have been provided by local, state, and fed- eral governments. Los Angeles County has also re- cently voted a bond issue of $179,000,000 to construct a system of works for drainage of storm waters. These are but major examples of the many such projects throughout California. Over 700 reservoirs in the State, some of which are operated wholly or partially for flood control, impound flood waters and enhance the value of downstream channel improvements. How- ever, in relatively few localities has complete or even reasonably adequate flood control been achieved. With expected continued growth of the State, a much higher degree of flood control must be provided to protect life and property. Results of the State-wide Water Resources Investi- gation to date indicate that if California is to at- tain growth and development commensurate with her manifold resources, nearly all of the potential res- ervoir storage capacity of the State must be con- structed and dedicated to operation for water con- servation purposes. This in itself will result in a substantial increase in downstream flood protection. However, any portion of the available reservoir stor- age capacity that is operated wholly or partially for solely flood control purposes will correspondingly re- duce the capacity available for conservation. Flood control operation requires the release of stored flood waters immediately upon expiration of the flood at rates within downstream channel capacities. Such operation is necessary so that possible snbsequent flood flows may be similarly detained in the reservoir and their discharge regulated. It is apparent that flood control reservoir operation is largely incom- patible with conservation, which requires detention of the stored flood waters until released upon demand for beneficial use. It is considered probable that under economic pressure attendant with ultimate develop- ment in California, flood control operation of reser- voirs will give way in some measure to their operation for conservation. Improvement of stream channels for flood protec- tion may also oppose the interests of water conserva- tion. Under natural conditions flood waters leave the stream channels and spread out over wide areas of adjacent alluvial lands. Depending upon permeability and the degree of saturation of the soils, varying amounts of the flood waters percolate to the underly- ing ground water basins. This is the principal source of replenishment for most of the economically vital ground water basins of California. Confinement of flood waters to restricted channels materially reduces the opportunity for percolation and ground water replenishment. This adverse effect is even more pro- nounced when the channels are lined with concrete or other impermeable materials, as they are in many instances in areas of acute ground water overdraft, particularly in southern California. To compensate for this impairment of the natural process, or to in- crease the natural conservation of flood waters in ground water reservoirs, artificial spreading works have been constructed in a number of places. Flood waters, either uncontrolled or temporarily stored in upstream reservoirs, are diverted and conveyed to the spreading grounds and allowed to percolate as rapidly as possible. Beneficial results from such arti- ficial spreading have been obtained in the Santa Clara Valley and in the South Coastal Area, and it is prob- able that extensive spreading works will be con- structed in the future. Drainage Drainage of high water table lands is a serious problem in many agricultural areas of California. Large acreages of developed lands have been lost to agriculture by water-logging, and in some instances by excessive salinity, brought about by over-irrigation and careless storage and conveyance of water. Further large areas of potential agricultural land cannot be utilized because of naturally high water tables. Exten- sive drainage works have been constructed in most ag- ricultural areas of the State, at both public and pri- vate expense, but large areas remain to be reclaimed. Such enterprise is doubly desirable in future efforts of California to meet its water requirements. Con- sumptive use of water from the high water table lands is a substantial economic loss, while the water sal- vaged in maintaining lower water tables may ordi- narily be put to beneficial consumptive use. Salt Balance The use of ground water storage capacity in con- serving and regulating both local and imported water supplies, particularly those supplies intended to be used consumptively by irrigated agriculture, requires the consideration of the salt balance involved in the use and re-use of the available supplies. The problem of salt balance exists in most of the developed ground water basins of California, and must be considered if the basins are to retain their important place in conservation and utilization of water in the State. The solution involves induced drainage of water from the basins in amounts suffi- cient to maintain satisfactory mineral quality therein. The amount of water so drained away will constitute a future demand on the developed water supply. Practically all natural waters contain mineral salts of calcium, magnesium, sodium, and potassium in varying amounts, present in the waters in the form of carbonates, sulphates, and chlorides. After applica- tion of water on the land, that part which is not con- 36 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA sumptively used and which does not drain off on the surface will percolate to the main body of ground water in free ground water basins. As a result of use some salt compounds will be given up in promoting growth or in combining with soil elements. Conversely, percolating water will absorb other salt compounds in passing through the soil between the surface and the water plane. Under natural conditions most ground water basins tend to fill with water and to overflow in the lower portions, thereby flushing out soluble salts contained in water originating on the tributary watershed and overlying lands. When aqui- fers in the basin are tapped by wells, the pumping draft lowers ground water levels to such an extent that in many cases the natural flushing of the basins ceases. Since the pumped water is largely used on overlying lands, soluble salts accumulate within the basin and tend to degrade the quality of the ground water in storage. If the situation is such that no dis- charge of water from the area, either surface or sub- surface, occurs, in the course of time the concentra- tion of salt compounds in the remaining water will become so great as to inhibit its use as a source of water supply. This is particularly true in the case of irrigation supplies, as crops generally have rather low tolerances for dissolved salts. In general, a salt balance can be established in a given area by deliberately inducing outflow of water from the area in such amount that the total quantity of mineral salts exported is the same as the quantity imported. Under these conditions the long-time mean quantity of salts is maintained as a constant quantity. The maintenance of such balance, or the removal of a total amount of salt from an area exceeding the salt input to the area (termed "favorable salt balance") does not necessarily imply lack of damage to the lands and crops. When existing ground water in storage is substantially more saline than the waters currently applied on the surface, the total quantity of salt in the effluent water is likely to be greater than that in the influent to the same area, and this condition will continue until all existing saline ground waters have been displaced. It is also important to determine whether a favorable salt balance is being maintained in the root zone of the irrigated crops, as accumula- tions of salt compounds in that zone will prevent the successful culture of many irrigated crops. Water Quality Full development of the waters of California for all beneficial uses will require thorough consideration of problems of water quality. Three general classes of water quality problems have been found to exist in California : (a) The use of water to carry away wastes re- sulting from urban and industrial development. (b) Empairment of the quality of water as a result of its development and beneficial use, (such as return irrigation water, sea-water intrusion, and damage to quality of ground waters resulting from improperly constructed, defective, and abandoned wells). (c) Naturally occurring poor quality water. Regulatory machinery to prevent unreasonable and adverse impairment of the quality of receiving waters to the detriment of the beneficial uses of the waters, from the discharge of sewage or industrial wastes, the first of the foregoing problems, was estab- lished in California in 1949. Section 13005 of the Water Code defines "pollution" as " ... an impairment of the quality of the Avaters of the State by sewage or industrial waste to a degree which does not create an actual hazard to the public health but which does adversely and unreasonably affect such waters for domestic, in- dustrial, agricultural, navigational, recreational or other beneficial uses." and "contamination" as " ... an impairment of the quality of the waters of the State by sewage or industrial waste to a degree which creates an actual hazard to the public health through poisoning or through the spread of disease. 'Contamination' shall include any equivalent effect resulting from the disposal of sewage or industrial waste, whether or not waters of the State are affected." Control of "pollution" is the responsibility of nine regional water pollution control boards. The State Water Pollution Control Board can review the acts of a regional board if it appears that appropriate action has not been taken by the regional board. Each of the regional boards has authority to prescribe require- ments as to the nature of any sewage or industrial waste discharge or the conditions to be maintained in the receiving waters. Both the state and regional boards have authority to formulate policy for the control of water pollution. The power of abatement of contamination is vested in the state and local health officers. Most of the problems caused by disposal of sewage and industrial wastes that previously existed in Cali- fornia have been corrected by the work of these agen- cies, and progress is being made on correction of the remainder as well as prevention of damage from new waste discharges. The Division of Water Resources was given author- ity in 1950 by Sections 229, 230, and 231 of the Water Code to study all water quality problems in the State, to report on them, and to recommend corrective action to the Legislature and the regional water pollution control boards. Studies have been initiated by the Division of many of the more pressing problems. Those completed to date have been concerned with specific conditions in limited areas. Studies are now in progress on such aspects as water quality objectives INTRODUCTION 37 necessary for water resource developments of state- wide magnitude, salt balance in ground water basins, minimum standards for well construction and aban- donment, sea-water intrusion to coastal ground water basins, and effects of irrigation return flows in the lower reaches of streams. Results of these current studies will be taken into account in the development of The California Water Plan. A discussion of the general aspect of the quality of water problems in California, particularly as it re- lates to water requirements, is presented in Appendix I, "Water Quality Considerations Affecting Use of the Waters of California." Costs of Water As has been stated, the relative costs of water have a considerable influence on the nature and amount of water utilization in the various parts of California, particularly as they affect the types of prevailing irrigated crops and industries, methods of water conservation and use, and efficiencies attained in con- servation, distribution, and application of water. In general, the effects are less apparent in connection with urban than with agricultural use of water. How- ever, high municipal water charges tend to prevent the establishment of certain large water-using indus- tries. They may in some cases reduce the per capita use of water, but this effect was not demonstrated in studies of the relationship of water cost to per capita use in connection with metered deliveries, recently conducted in the San Francisco Bay Area. It has been generally observed throughout California, however, that by installing water meters and imposing metered rates the per capita use of water is reduced in amount from that prevalent during prior flat rate service. Extensive study of the cost of water in California was not made in connection with the current investi- gation. However, a few examples will serve to indi- cate the range in unit cost for irrigation and urban supplies in various parts of the State. In the Turlock Irrigation District in the San Joaquin Valley, the assessment for irrigation water now averages about $1.25 per acre per year, and entitles the farmer to a maximum of four acre-feet of water per acre. This extremely low charge is made possible by efficient district management and by subsidy through income from sale of hydroelectric power produced by the district. In contrast, the average annual assessment in one irrigation district in southern California is about $24 per acre per year. To this is added water charges that result in a total annual cost of water of from about $60 to $70 per acre, depending upon the amount of pumping required to reach the land to be served. On the average, the cost to the farmer of pumping irrigation water from wells in California is of the order of about four to six cents per acre- foot per foot of lift. In the Central Valley Area the cost to a typical irrigator pumping 1,000 gallons per minute from a depth of 80 feet is approximately $3.50 per acre-foot. This includes costs of power, operation and maintenance, and capital investment. The cost of urban water in California shows similar variation. In many municipalities of the Sacramento Valley water is plentiful and low flat rate charges prevail. In the City of Sacramento flat rates average about $1.50 per month for single-family residences, and wholesale rates are correspondingly low. Rates for single-family domestic metered service by major utilities in the San Francisco Bay Area vary from about 30 to 40 cents per 1,000 gallons. For an average consumer these rates result in monthly charges of from about $3.00 to $4.00. Average wholesale rates in the Bay Area for industries and other large water users vary from about 25 to 30 cents per 1,000 gal- lons. In the Los Angeles Metropolitan Area single- family residential rates average from about 20 to 40 cents per 1,000 gallons. Inasmuch as the per capita water use is slightly greater in Los Angeles than in San Francisco, the average domestic consumer's monthly bill varies from about $3.00 to $5.00. Whole- sale water rates in the Los Angeles area vary from about 12 to 30 cents per 1,000 gallons. It is believed that the cost of water will not be a limiting factor in ultimate development of the water resources of California. Today, as in the past, expen- sive urban water supply works, resulting in relatively high charges to consumers, are readily financed to meet existing shortages or anticipated future water needs. It is indicated that urban communities will always be able and willing to pay the cost of water to meet their municipal needs. Furthermore, it is considered probable that under pressure of future demands for agricultural produce the water necessary for a greatly expanded irrigation development will be provided, at whatever cost may be required. For these reasons, in current studies in preparation of The California Water Plan, the indicated present cost of water and present financial feasibility are not necessarily being taken as determining factors in selection of project features. Many works financially infeasible today will undoubtedly be financed and constructed in the future. In the current studies, how- ever, full consideration is being given to indicated relative costs of possible alternative project features, with choice being given to those demonstrating the least cost. CHAPTER II METHODS AND PROCEDURES The complexity and magnitude of the task of as- sembling and interpreting basic data presented in this bulletin, and of forecasting growth of California and her water requirements, justify some explanation of the methods and procedures involved. In general, the process included: (1) the collection of survey data and information from all available sources, (2) the conduct of supplemental surveys as required, (3) compilation of the data and information in present- able form, (4) interpretation and projection of the data and information, and (5) reference of the re- sults to the best available authorities for review based on their experience and judgment. The methods and procedures employed are described in this chapter, and in order to avoid repetition are only referred to in ensuing chapters when significant departures from the general practice were involved. DEFINITIONS The following definitions of certain terms and con- cepts, as used in this bulletin, are presented to facili- tate understanding of the ensuing subject matter. Annual — This refers to the 12-month period from January 1st of a given year through December 31st of the same year, sometimes termed the "calendar year. ' ' Seasonal — This refers to any 12-month period other than the calendar year. Precipitation Season — The 12-month period from July 1st of a given year through June 30th of the following year. Runoff Season — The 12-month period from October 1st of a given year through September 30th of the following year. Average Monthly Temperature — The monthly aver- age of daily averages of maximum and minimum temperatures. Mean Period — A period chosen to represent condi- tions of water supply and climate over a long series of years. For purposes of the current investigation the mean precipitation period embraces the 50 seasons from 1897-98 through 1946-47, and the mean runoff period the 53 seasons from 1894-95 through 1946-47. Mean — This is used in reference to arithmetical aver- ages relating to mean periods. Average — This is used in reference to arithmetical averages relating to periods other than mean periods. Present — This is used generally in reference to land use and water supply conditions prevailing during the period from 1945-46 through 1952-53. Ultimate — This is used in reference to conditions after an unspecified but long period of years in the future when land use and water supply develop- ment will be at a maximum and essentially stabi- lized. Water Utilization — This term is used in a broad sense to include all employments of water by nature or man, whether consumptive or nonconsumptive, as well as irrecoverable losses of water incidental to such employment, and is synonymous with the term "water use." Factors of Water Demand — Those factors pertaining to rates, times, and places of delivery of water, quality of water, losses of water, etc., imposed by the control, development, and use of the water for beneficial purposes. Water Requirement — The water needed to provide for all beneficial uses and for all irrecoverable losses incidental to such uses. Present Supplemental Water Requirement — The ad- ditional water needed to provide for all present beneficial consumptive uses of water and for irre- coverable losses incidental to such use over and above the safe yield of the present water supply development. Probable Ultimate Supplemental Water Requirement — The difference between the present and probable ultimate water requirement, added to the present supplemental water requirement if such exists, or minus the ultimate developed water supplies of the Friant-Kern, Madera, and Contra Costa Canals in the areas where they apply. Consumptive Use of Water — This refers to water con- sumed by vegetative growth in transpiration and building plant tissue, and to water evaporated from adjacent soil, from water surface, and from foli- age. It also refers to water similarly consumed and evaporated by urban and nonvegetative types of land use. Applied Water — The water delivered to a farmer's headgate in the case of irrigation use, or to an in- dividual's meter in the case of urban use, or its equivalent. It does not include direct precipitation. ( 39 ) 40 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Effective Precipitation — That portion of the direct precipitation which is consumptively used and which does not contribute to stream flow or perco- late to the ground water. Irrigation Efficiency — The ratio of consumptive use of applied irrigation water to the total amount of water applied, expressed as a percentage. Irrigation Water s< rvice Area Efficiency — The ratio of consumptive use of applied irrigation water in a given service area to the gross amount of water de- livered to the area, expressed as a percentage. Natural Flow — The flow of a stream as it would be if unaltered by upstream diversion, storage, import, export, or change in upstream consumptive use caused by development. Impaired Flow — The actual flow of a stream with any given stage of upstream development. Aquifer — A geologic formation or structure suffi- ciently permeable to yield water to wells or springs. Free Ground Water — A body of ground water not immediately overlain by impervious materials, and moving under control of the water table slope. Confined Ground Wafer — A body of ground Avater immediately overlain by material sufficiently im- pervious to sever free hydraulic connection with overlying water, and moving under pressure caused by the difference in head between the intake or fore- bay area and the discharge area of the confined water body. Safe Surface Water Yield — The maximum dependable rate at which surface water would be available throughout a chosen critically deficient water sup- ply period, with a given stage of surface water supply development. Saft Ground Water Yield — The maximum rate of net extraction of water from a ground water basin which, if continued over an indefinitely long period of years, would result in the maintenance of certain desirable fixed conditions. Commonly, safe ground water yield is determined by one or more of the following criteria : 1. Mean seasonal extraction of water from the ground water basin does not exceed mean sea- sonal replenishment to the basin. 2. Water levels are not so lowered as to cause harmful impairment of the quality of the ground water by intrusion of other water of undesirable quality, or by accumulation and concentration of degradants or pollutants. •'!. Water levels are not so lowered as to imperil the economy of ground water users by exces- sive costs o!' pumping from the groundwater basin, or by exclusion of users from a supply therefrom. Ground Water Overdraft — The rate of net extraction of water from a ground water basin in excess of safe ground water yield. Quality of Water — Those characteristics of water af- fecting its suitability for beneficial rises. Pollution — Impairment of the quality of water by sewage or industrial waste to a degree which does not create a hazard to public health, but which ad- versely and unreasonably affects such water for beneficial uses. Contamination — Impairment of the quality of water by sewage or industrial waste to a degree which cre- ates a hazard to public health through poisoning or spread of disease. Degradation — Impairment in the quality of water due to causes other than disposal of sewage and indus- trial wastes. GEOGRAPHICAL SUBDIVISION OF CALIFORNIA For purposes of this bulletin the State was divided into seven major hydrographic areas, coinciding with those utilized in Bulletin No. 1, "Water Resources of California," and these major areas were further sub- divided into "hydrographic units." The portion of California included within each hydrographic area and the numbers and names by which they are desig- nated are : 1. North Coastal Area. Lower Klamath Lake and Lost River Basins, and all basins draining into the Pacific Ocean from the California-Oregon state line southerly to the northern boundary of Lagunitas Creek Basin in Marin County. 2. San Francisco Bay Area. All basins draining into San Francisco, San Pablo, and Suisun Bays, and into Sacramento River downstream from Collinsville; Winter and Browns Islands in Contra Costa County; basins west of the eastern boundary of Kirker Creek Basin in Contra Costa County; and basins directly tributary to the Pacific Ocean from the northern boundary of Lagunitas Creek Basin to the southern boundary of Peseadero Creek Basin, in San Mateo and Santa Cruz Counties. 3. Central Coastal Area. All basins draining into the Pacific Ocean from the southern boundary of Peseadero Creek Basin in Santa Cruz County, to the southeastern boundary of Rincon Creek Basin in the western part of Ventura County. 4. South Coastal Area. All basins draining into the Pacific Ocean from the southeastern boundary of Rincon Creek Basin to the California-Mexico boundary. 5. Central Valley Area. All basins draining into the Sacramento and San Joaquin Rivers above the eastern boundary of the San Francisco Bay Area near Collinsville, including Goose Lake Basin in Modoc County. METHODS AND PROCEDURES 41 6. Lahontau Area. All basins east of the Santa Ana and Los Angeles River Basins and all basins east of the Central Valley Area, between the Cali- fornia-Oregon boundary and the southern boundary of basins draining into Antelope Valley and Mojave River, and into Dry Lake Basin near the Calfornia- Nevada line north of Ivanpah. 7. Colorado Desert Area. All basins east of the South Coastal Area that drain into the Colorado River within California ; also Salton Sea Basin and local sinks between the southern boundary of the Lahontan Area and the California-Mexico boundary. The hydrographic units, into which the major hydrographic areas were subdivided, Avere established for purposes of required hydrologic study. Descrip- tions of the units are contained in Appendix C. The hydrographic unit boundaries were determined from consideration of water supply and related Avater serA T ice. Boundaries were established in the Central Valley Area so that a major stream basin includes two units, one an upstream mountainous or predomi- nantly Avater-source unit, and the other a doAvnstream A T alley floor or predominantly water-using unit. Bound- aries of hydrographic units in the North Coastal, Central Coastal, South Coastal, Lahontan, and Colo- rado Desert Areas encompass entire stream basins in most cases. The San Francisco Bay Area, because of its highly developed urban nature, was divided into units designed to facilitate study of established water service areas, as were the metropolitan areas in and around Los Angeles and San Diego in the South Coastal Area. Locations of the major hydrographic areas and of the hydrographic units, together with their numerical designations, are shown on Plate 8, "Major Hydro- graphic Areas and Hydrographic Units." CLASSIFICATION OF WATER SERVICE AREAS The lands of California Avere segregated into three broad areal classifications according to the nature of their present or expected future water service for the purpose of determining eonsimiptive vrater require- ments, as follows : (1) Irrigable lands — lands presently irrigated, as well as those additional lands which are suitable for irrigation under conditions of probable ultimate de- velopment. The lands so classified Avere further segre- gated on the basis of types of principal crops. (2) Urban and suburban areas — lands which are presently, or Avill probably ultimately be devoted to urban and suburban use. In the San Francisco Bay Area and in most of the South Coastal Area, these lands were further classified on the basis of principal types of urban land use, such as residential, commer- cial, industrial, etc. (3) Other water service areas — the remaining area of the State, other than the irrigation and urban and suburban water service areas, which contains lands either now or in the future requiring water service, but which cannot be placed in either of the foregoing classifications. Under present conditions, this area receives water service for limited specialized purposes such as recreational development, isolated industrial plants, military establishments, evapora- tion from valley floor reservoirs in the Central Valley Area, wild fowl ponds, etc., and the actual aggregate water service area is relatively insignificant. For this reason, these remaining lands Avere not segregated comprehensively as regards types of present land use, and are hereinafter referred to as "unclassified areas." It was assumed that under conditions of probable ultimate development, in addition to alloAV- ances for expansion of irrigation and urban and suburban water service areas, all of the remaining lands of the State will require water service. This large area will be generally subject to only sparse development even under such conditions of ultimate development, and is hereinafter referred to as " other water service areas." Irrigation is presently by far the most important consumptive employment of water in California, in terms of quantity of Avater requirement, and will probably maintain this position under conditions of ultimate development, From a quantitative stand- point, the next most important consumptive water requirement is for urban and suburban develop- ments. Other consumptiA'e Avater requirements, con- sidered quantitatively, are minor in amount, On the basis of the relative importance of the irrigation water requirement, particularly as it pertains to planning for water resource development, it folloAVS that the greatest emphasis in studies for this bulletin was placed on the determination of present and prob- able ultimate irrigation water service areas. Urban and suburban Avater requirements for present and probable ultimate urban and suburban water service areas Avere studied in considerable detail, although not to the same degree of intensity as the irrigation requirements. Urban and suburban use of water in the case' of the three cited major metropolitan areas will be paramount in the future, and therefore urban and suburban Avater service areas included therein were given detailed treatment and emphasis. In ac- cordance with its relatively minor consumptive water requirement, the third general classification, "other water service areas," was given relatively less de- tailed study and consideration. MAPS A series of maps is included with this bulletin de- picting present and probable ultimate water service areas throughout California. This series is designated 42 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA as Plate 9, and is entitled "Classification of Lands for Water Service From The California Water Plan." Shown in distinctive colors are the present irrigation water service areas, urban and suburban water serv- ice areas, and additional lands considered to be future irrigation or urban and suburban water service areas. "Other water service areas" under ultimate condi- tions of development comprise the remainder of the State. Present military areas, as well as tidal and sub- merged lands subject to possible future reclamation in the San Francisco Bay Area, are shown by distinc- tive conventions. The series of maps also shows the location of principal physical and cultural features. place names, and latest available topography. The in- dividual map sheets, 26 in number, each cover one degree of latitude and varying degrees of longitude, and are drawn to a scale of 1 to 500,000. The maps were adapted from a base map published by the United States Geological Survey in 1952 and show only those water service areas of one square mile or greater in area. In addition, there is an index sheet which identifies by number the various portions of the State covered by the individual map sheets. On Plate 1, "Water Service Areas for The California Water Plan," the present irrigation and urban and suburban water service areas and the additional lands suitable for future irrigation and urban and suburban development, shown on the foregoing series, are gen- eralized for the purpose of presenting a composite of present and probable ultimate water service areas for the State as a whole. Greater detail than was possible with the foregoing map series was desirable for presently highly devel- oped lands around San Francisco Bay and in and around Los Angeles and San Diego. Two supplemental series of maps cover these metropolitan areas at a scale of 1 to 125,000, and show the present residential, commercial, industrial, and irrigated agricultural lands in distinctive colors. Lands with certain special- ized uses, such as salt ponds, which depart materially in water requirement from that of other industrial lands, are shown by special conventions. The San Francisco Bay Area is covered by a series of 11 map sheets and an index sheet, designated Plate 10, and entitled "Present Land Use in San Francisco Bay Area." Coverage of the Los Angeles and San Diego Metropolitan Areas consists of a series of nine and two map sheets, respectively. One index sheet serves for both of these latter metropolitan areas, and the series is designated Plate 11, and entitled "Present Land I'se in Los Angeles and San Diego Metropolitan Areas. " Recenl United States Geological Survey quad- gles served as the base for preparation of these map series. In addition to the foregoing general map coverage, several specialized maps are included to illustrate the subject matter of this bulletin. Plate 3 shows the irri- gation and water storage districts in the State. These agencies supply the majority of the irrigation water requirements of the State. Plate 4 depicts the known ground water basins of California, as well as those additional areas of valley fill that may or may not comprise ground water basins at the present time or in the future. Plate 5 shows the present hydroelectric power development in the State, including power plants, principal transmission lines, and reservoirs used principally for hydroelectric power production. Plate (i shows the timber-producing lands of the State and the general location of auriferous gravel deposits. Plate 7 shows the recreational areas including national parks, monuments, and forests, and state beaches and parks. Plate 8 shows the boundaries of the seven major hydrographic areas of California, and of the hydro- graphic units into which the areas were divided for purposes of hydrologic analysis. Plate 12 shows the principal public and private agencies and water sup- ply works serving the San Francisco Bay Area at the present time, while Plate 13 depicts similar informa- tion for the Los Angeles and San Diego Metropolitan Areas. GENERAL DESCRIPTION OF METHOD OF DETERMINING WATER REQUIREMENTS The basic method used in estimating water require- ments was, first, to determine the areas of various types of water service according to the classifications previously described, based generally on survey data. and, second, to derive appropriate unit values of consumptive water use for each particular class and type of land use, based largely on available experi- mental and investigational data. Unit values of con- sumptive use of water were subsequently applied to the established water service areas to estimate the total consumptive use. The w ? ater service area effi- ciency was then applied to the consumptive use figure to determine the total water requirement, generally measured in terms of consumptive use of applied water plus all unavoidable losses. With respect to water requirements for "other water service areas," there were variations from the foregoing procedure in that derivation of some of the water requirements w y as made on a per capita or unit of production basis rather than on an area! basis. The supplemental water requirements under condi- tions of probable ultimate development generally were evaluated as the difference between present and ulti- mate water requirements, plus any existing present supplemental water requirement. Where a present deficiency in available water supply exists, the safe yield of the present water supply development was determined from available data and compared with the present water requirement, the difference being the present supplemental water requirement. METHODS AND PROCEDURES 43 Data secured from field surveys and from office analysis of pertinent estimates for ultimate develop- ment are presented in tables pertaining to each hydrographic area. The tabular data were gener- ally rounded to three significant figures, with the totals rounded as necessary to accord with the same standard. SURVEYS OF PRESENT WATER SERVICE AREAS Data as to the nature, location, and areal extent of lands in California to which water other Hum precipitation is presently applied were obtained, in- sofar as they were available, from federal, state, and local agencies. These data generally were based on results of field surveys, segregated in accordance with various classes and types of land use, and are regularly determined by many water service agen- cies as a part of their operational procedures. The Bureau of Reclamation of the United States Depart- ment of the Interior, in planning for and operating the Central Valley Project, has made land use surveys of much of the irrigated area on the floor of the Cen- tral Valley. The Division of Water Resources, in connection with recent and current water resources investigations, has surveyed water-using lands in many areas of the State. Additional field surveys to supplement the available land use information were conducted in order to obtain complete coverage of water service areas in California. Because of the rela- tively great importance of the metropolitan areas in and around San Francisco Bay, Los Angeles, and San Diego, special detailed land use surveys were conducted in these areas. Surveys of present water service areas conducted during the investigation were accomplished generally by field inspection, using aerial photographs or suit- able maps to delineate boundaries of the various classifications. Areas so delineated were then meas- ured, and the data compiled in combination with that from other sources. Combined data were then tabu- lated as desired for presentation in this bulletin. "Within the scope of the present investigation, it was impracticable to survey during any single season all areas receiving water service in California. Tabu- lations of present water service areas included herein represent a composite of survey data covering the period from 1946 through 1953, which is the period referred to in this bulletin in discussing present con- ditions of development in California. The pictorial presentation of present water service areas shown on the individual sheets of Plate 9 depicts all lands that received water service during one or more years of this designated present period. Irrigated Lands Data from surveys of irrigated lands in California were tabulated in such form as to permit grouping of crops having similar water-using characteristics, and which were raised under similar agricultural practices. The crop groups varied throughout the State, dependent upon the nature of the survey data and the distribution of crops. Indicative of the nature of the irrigated crop groupings is the following for the Central Coastal Area : Alfalfa _ Hay, seed, and pasture Pasture Grasses and legumes, other than alfalfa, used for livestock forage Orchard . Deciduous fruit, nuts, and olives Citrus Oranges, lemons, grapefruit, and avocados Vineyard All varieties of grapes Truck crops Intensively cultivated fresh vege- tables, including tomatoes, lettuce, artichokes, brussels sprouts, cab- bages, carrots, peppers, broccoli, flower seed, and nursery crops Sugar beets Miscellaneous field crops Dry beans, milo, corn, hops, hay. grain, etc., and unsegregated sugar beets in Santa Barbara County The coverage of the land use surveys in most parts of the State was limited to areas of irrigated crops. However, on the valley floor of the Central Valley Area, in the three major metropolitan areas, and in several localities where special water resource inves- tigations had been conducted, the data obtained were complete on an areal basis, embracing all types of land use, both natural and man-made, within the survey boundaries. Delineation of irrigated lands Avas largely accom- plished on the basis of their gross area. That is, in general, the included areas of roads, railroads, rights of way. farm lots, and other nonagricultural parcels within the irrigated lands were not segregated at the time of the survey. These items were later evaluated by application to the gross surveyed areas of appro- priate percentage factors, determined from detailed surveys of representative sample plots. In the case of most mountain and foothill areas and certain other relatively sparsely developed agricultural areas, irri- gated lands as originally plotted on aerial photo- graphs in the field were assumed to represent net areas. This was permissible because the included rights of way and nonagricultural lands were very minor in extent. At the request of the Division of Water Resources, irrigated lands within the boundaries of national 44 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA forests and national parks and monuments were sur- veyed by the federal agencies having administrative jurisdiction of these lands. Each such agency reported the irrigated acreage by types of crop, location, and quantity of water pumped or diverted for the purpose of irrigation. Information as to the sources of data regarding areas of irrigated lands and approximate dates of the surveys is presented in Appendix D. Urban and Suburban Areas In most of the State the areas classified in this bulletin as urban and suburban consist of those lands in and adjacent to towns and cities that are charac- terized by commercial, industrial, residential, and re- lated community types of development. Such a typ- ical urban and suburban area might be composed of a central business and commercial district, one or more adjacent industrial districts, and surrounding residential and suburban districts, together witli in- cluded parks, schools, streets, airfields, vacant lands, etc. Lands devoted to urban and suburban development in the Central Valley Area and in most of the South Coastal Area, and in several other localities where special Avater resources investigations have been con- ducted, were determined in varying detail from field survey data. In order to make this determination, it was usually the procedure to assume an arbitrary criterion for delineating the boundary between such urban and suburban lands and surrounding lands. Generally, the boundary was established to include all lands in the urban and suburban classification where at least 10 per cent of the gross area was oc- cupied by designated urban and suburban types of land use. In the South Coastal Area, however, no lines were drawn delimiting the gross urban and suburban areas, and all lands devoted to these types of use were included in the totals even when isolated from urban centers. In the Klamath River drainage basin esti- mates were made of all the urban and suburban areas by eon verting population to acres by the application of a density factor. The areal extent of urban and suburban lands throughout the remainder of California was deter- mined by measurements made on the latest and most accurate available maps or photographs. In the case nf a few small communities where no other appro- priate information was available, the urban and suburban areas were computed by dividing 1950 cen- sus population figures by the average population density of similar towns in the vicinity. Metropolitan Areas in the case of irrigated lands in the agricul- tural portions of the State, detailed surveys of land use in the three large metropolitan areas, in and around San Francisco, Los Angeles, and San Diego, were made for the purpose of grouping development types having similar characteristics as regards water use. Recent zoning maps of the areas being surveyed were obtained from the planning agency of the re- sponsible local political subdivision, for use in deter- mining the various prevailing types of urban land use, as well as their general locations within the area. The principal types of land use considered were residential, commercial, and industrial. In those cases where the indicated unit values of water use departed materially from the average for these principal types, further subdivisions were made. Thus, multiresiden- tial areas were segregated from residential, and tank farms, airports, and other low water-using industries were segregated in the industrial areas. Available recent maps or aerial photographs were then obtained and provisional determination of the various land use types was accomplished in the office by inspection of the maps and aerial photographs in conjunction Avith the zoning map. Blocks of the area were identified as to their prevailing urban land use type and then field-inspected, resulting in verifying or changing the office determinations as required. Following this gross classification of the blocks, the net area actually devoted to the indicated prevailing urban type of use was determined by eliminating the areas of streets, highways, and vacant lots, which were estimated as percentages of the total, and by similarly estimating the percentages of the total area represented by land use types differing from the dom- inant type in the block. Where agricultural and urban uses of land were interspersed, either a crop classification was estimated for the irrigated agri- cultural portion and expressed in terms of percentage of the whole area, or the irrigated lands were classi- fied as to crop type during the survey. Unclassified Areas Certain present water-using lands in California, not falling into the foregoing major classifications, were difficult to delineate, while in the case of others the areal extent bore little relationship to the amount of the water requirement. Such present areas, there- fore, were not surveyed and delineated in detail, but the water requirements were generally determined on a per capita or unit of production basis, rather than on an areal basis. For purposes of this bulletin, this category of present water service area is referred to as "unclassified." In general, the unclassified area receiving water service includes scattered developed portions of na- tional forests, parks and monuments, public beaches and parks, private recreational areas, military reser- vations, wild fowl refuges, and artificial water sur- faces on the valley floor of the Central Valley Area that consume water by evaporation. Military reserva- tions in the South Coastal Area, however, were not METHODS AND PROCEDURES 45 segregated as a separate land use type, the included water service areas being assigned to the appropriate irrigated agricultural or urban and suburban classifi- cation. The extent of unclassified lands receiving water service was estimated on the basis of informa- tion from agencies having jurisdiction and from any other available competent sources. The determina- tion of artificial water surface areas was largely based on data compiled in a publication of the State Divi- sion of Water Resources, entitled "Dams Within Jurisdiction of the State of California," February 1, 1950. METHOD OF FORECASTING ULTIMATE WATER SERVICE AREAS In forecasting the probable ultimate water service areas of California, the anticipated extent of future urban and suburban types of development was first determined. Existing urban centers and surrounding suburban devlopments were assumed to generally con- stitute the nuclei for ultimate urban and suburban water service areas, and it is believed that future growth of this type will be largely in and around such present centers. The remaining lands of the State were surveyed to determine the areas suitable for irrigated agricultural development. It was assumed that all such suitable lands will ultimately be devel- oped and served with water for irrigation. The lands not assigned to either of the foregoing major classifi- cations were not segregated in detail with regard to their expected ultimate type of land use. It was as- sumed, however, that ultimately all of these remain- ing lands will contain at least sparse development re- quiring water service, and, as previously stated, they are herein designated "other water service areas." The use of water for irrigation creates the major water requirement in California, a condition that is anticipated to continue even under probable ultimate conditions of development. Consequently, the forecast of the ultimate irrigated area of the State was of pri- mary importance in estimating the ultimate water re- quirement. The methods used in the determination of irrigable areas and irrigated lands under probable ultimate conditions are outlined in considerable detail in the ensuing section. Irrigable and Irrigated Lands The extent and location of the irrigable lands of California were determined by collecting, reviewing, and compiling appropriate land classification survey data available from other agencies, supplemented by data obtained from field surveys conducted as re- quired by the Division of AVater Resources during the investigation. Agencies whose land classification survey data were so used include the Bureau of Rec- lamation of the United States Department of the In- terior, the Bureau of Agricultural Economics of the United States Department of Agriculture, and the Agricultural Experiment Station of the University of California. Appendix E presents a tabulation of the areas classified by the aforementioned agencies. New developments in irrigation practice in recent years and new irrigated crops have modified former concepts of the types of land suitable for irrigated agriculture. Lands formerly considered nonirrigable because of excessive slope or roughness of topography are now being irrigated satisfactorily by sprinklers, which make feasible the irrigation of nearly all land otherwise suitable and capable of holding the soil against erosion. The successful irrigation of ladino clover and certain other irrigated forage crops has resulted in a rapid expansion of the acreage devoted to irrigated pasture, and has justified the development of lands with shallow soils formerly considered non- irrigable. These recent technological developments made it necessary to review and revise some of the land classification data supplied by other agencies which had been based on past standards, and to cor- relate earlier standards with those established by the Division of Water Resources for the present investi- gation. Standards for Determination of Irrigability of Lands. The suitability of land for irrigation devel- opment is influenced by many factors. Those factors relating to the production and marketing of clima- tically adapted crops have marked influence upon the successful development of certain types of land for irrigation. The cost of water and the size, shape, and location of the parcels of land with respect to the water supply are also significant factors. Further- more, climatic conditions influence crop adaptability and thus indirectly affect the irrigability of the lands. Contrasting with these more or less indirect factors of irrigability are the physical characteristics of the land and the inherent conditions of the soil itself which directly affect the adaptability of the land for irrigation development, and which are generally sub- ject to relatively little change with variation in local or general economic conditions. Studies for this bulletin resulted in the determina- tion that the most permanent and significant classifi- cation of the lands, as regards their suitability for irrigation development, would be obtained if the standards were based upon the more stable physical characteristics of the land and inherent conditions of the soil. These standards kept the cited economic factors as separate variables, making it possible to re- appraise the present land classification at any future date in view of economic conditions existing at that time. The land classification standards used in studies, for this bulletin, therefore, were based upon physical factors and inherent conditions of (1) soils, (2) to- pography, and (3) drainage. 46 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA (1) Soils. The characteristics of soils that prin- cipally establish their suitability for irrigation are depth, texture, and structure. These physical factors to a large extent determine the moisture-holding capac- ity, the root zone area, the ease of cultivation and irrigation, and the available nutrient capacity of the soils. (2) Topography. Topographic conditions consid- ered in the land classification included the degree of slope, the undulation of the land, and the amount of cover as represented by loose rock and rock outcrop- pings. These factors directly affect the ease of irriga- tion and determine the type of irrigation practice best suited to provide the land with water in sufficient quantity to meet crop needs, without soil erosion or excessive losses of water through surface runoff. (3) Drainage. Drainage is highly important in determining the irrigability of land, as the problems of salinity and alkalinity are closely associated with it. For purposes of the present studies it was assumed that under conditions of ultimate development most lands physically capable of drainage reclamation will be reclaimed. Thus, in the land classification rela- tively little land was determined to be nonirrigable because of its present condition as regards drainage, if it appeared that drainage and reclamation would be practical in the future. Results of the land classification surveys presented herein are not segregated into several classes as re- gards their adaptability to irrigation, although much of the data was field mapped and compiled in that manner. Maps and tabulations of such data obtained from other agencies involved somewhat different sys- tems of classification, and in many cases could not icadily be correlated directly with the land classes established for use by the Division of Water Re- sources. Furthermore, in many parts of the State the scale and detail of available base maps would not al- low delineation of several irrigable land classes. In these cases, necessity limited the classification to a basic determination of whether or not the land was pre- dominantly irrigable. It is probable that acreage de- terminations in future studies of irrigable lands in many areas of California will deviate from acreages as shown herein. The planning for definite future projects in those areas requires that stricter standards as to irrigability will be applied due to economic factors concerned with the feasibility of developing water supplies. In general, the lands of California classified as irrigable in this bulletin meet the mini- mum requirements set forth in Table 1. Land Classification Survey Procedure. The field mapping procedures utilized during the investigation for the delineation of irrigable lands were basically the same throughout the State. The character of the soils was established by examination of materials TABLE 1 STANDARDS FOR CLASSIFICATION OF LANDS AS IRRIGABLE Land characteristics Minimum requirements Soils Texture Loamy sand to permeable clay. Deptli To sand, gravel, or cobble. _ 18 inches of good free-working soil of fine sandy loam or heavier, or from 24 to 30 inches of lighter textured soil. To bedrock At least 18 inches over shattered bedrock or tilted shale bedrock; or 24 inches over massive bedrock or hardpan. Topography Slopes Smooth slopes up to no more than 30 per- cent in general gradient in reasonably large-sized bodies sloping in the same plane; or undulating slopes which are less than 20 percent in general gradient. Rock cover No more than enough loose rock and rock outcroppings to moderately reduce productivity and interfere with cultural practices. Varies with soil depth and topographic conditions. Erosion No more than moderate erosion, with very few gullies which are not crossable by tillage implements. Drainage Soil and topography Such that moderate farm drainage may be required, but without excessive cost. Salinity Total salts in the soil solution do not exceed 0.5 percent, except in readily drained soils where reclamation appears feasible. Alkalinity.. The pH value is 9.0 or less, unless the soil is calcareous in which case higher values may be allowed. If there is evidence of black alkali a lower pH value may be limiting. from test holes, road cuts, and ditch banks, together with observation of the type and quality of natural vegetation or crops. In classifying lands of the Mo- jave and Colorado Deserts, but excluding those areas having rights in and to the waters of the Colorado River, this procedure was supplemented with labo- ratory determinations of moisture-holding capacities of soil samples taken from representative lands. The Soil Conservation Service of the United States De- partment of Agriculture cooperated in this activity by making available laboratory facilities and profes- sional assistance. In general, topographic and drain- age conditions were estimated from examination of topographic maps, supplemented and cheeked by ob- servations in the field. Characteristics of the soils and topographic and drainage conditions were delineated and recorded on the most suitable maps or aerial photographs available. The areas in the Colorado Desert Area having rights in and to the waters of the Colorado River are not classified in this bulletin. Some variations in the degree of mapping detail were necessary as a result of differences in scales of available base maps. In this connection, the quality and scale of the available topographic maps materi- ally affected the accuracy of determination of topo- graphic and drainage factors. The base maps utilized for a large part of the State were either Geological Survey or Forest Service topographic maps at scales METHODS AND PROCEDURES 47 of 1 to 62,500 or 1 to 125,000. Topographic maps were not available in a few areas, and county or State Di- vision of Forestry maps were utilized. In other areas, covered by recent special water resources investiga- tions, the irrigable areas were delineated on aerial photographs and topographic maps at a scale of ap- proximately 1 to 20,000. Determination of Irrigable Lands That Will Ulti- mately Be Irrigated. The amount of the land classi- fied as irrigable that will be actually irrigated in any one year under conditions of ultimate development probably will depend on one or more of the follow- ing factors : (1) Quality of the Land. It is anticipated that in the future the higher quality irrigable lands will be intensively developed for irrigation and will remain in relatively continuous operation, whereas lands of poorer quality and of limited crop adaptability will be in production only as favorable economic condi- tions permit. (2) Irrigable Areas Utilized for Purposes Other Than Agriculture. It is anticipated that there will always be a portion of the irrigable lands that will be occupied by urban types of development, farm lots, highways, railroads, canals, industrial establish- ments, etc. The nature of the agricultural develop- ment will to some extent determine the amount of certain of these nonagricultural land uses. For ex- ample, orchard and truck farming areas ordinarily include more land used for roads and farmsteads than areas where field crops are dominant. (3) Nonirrigable Lands. The areas of small plots of nonirrigable land included within the areas classed generally as irrigable varied with the detail of the survey and classes of land being surveyed. Analysis of typical areas throughout the State developed factors which were applied to topographically similar areas in order to estimate the magnitude of nonir- rigable land included in the general boundaries de- lineating the area of irrigable lands. The nonirrigable areas and the irrigable areas utilized for purposes other than agriculture were subtracted from the gross irrigable area to determine the net irrigated area under estimated idtimate conditions. (4) Size, Shape, and Location of the Irrigable Land. It is apparent that small, irregularly shaped plots of land, particularly those isolated from other irrigable lands, cannot be irrigated readily or as com- pletely as large, regular, compact units. (5) Climatic Influences. Considering lands of equal inherent agricultural quality, it is improbable that as intensive irrigation practices will develop in localities where rainfall is sufficient to support some dry farming, as in areas with a more arid climate where irrigation is an absolute necessity for crop pro- duction. The length of the growing season and the danger of unseasonable frosts are other factors that affect adaptability and production of crops, thus in- directly affecting the cultural practices and the inten- sity of irrigation. (6) Economic Conditions. The economic effects of crop production costs and net returns are recognized as the most influential factors in limiting the annual irrigated acreage. It is probable that there will always be a tendency to withdraw land from produc- tion in years of economic adversity. Inasmuch as the concept of ultimate development adopted for pur- poses of the present studies presupposes maximum land use within physical limitations, economic factors were not given consideration in determining the prob- able ultimate irrigated area. This assumption is con- servative in relation to water requirements, in that the estimated requirements have thus been maximized in this stage of planning for future water resources development. The area that will actually be irrigated in Califor- nia in any one year under probable conditions of ultimate development was estimated by the applica- tion of two percentage factors. One factor reflects an estimate of the included land ultimately to be devoted to farm lots, highways, railroads, canals, etc., and varied from 93 to 96 per cent, based on results of analysis of representative irrigation developments. The second factor reflects those items of land quality, inclusion of nonirrigable land, and size, shape, and lo- cation of the irrigable land, and varied from 69 to 97 per cent, based on results of analysis of representative irrigation development, as well as experience and judgment. Where the irrigable land was subdivided into classes as to suitability for irrigation, the factors varied with the class. In the case of irrigable lands not so classified, an approximation of the areas of the several classes was estimated in order to provide a basis for using the factors. Probable Ultimate Crop Pattern. The kinds and amounts of crops that eventually will be grown on lands to be irrigated in California will affect the amount of the ultimate water requirement. Determi- nation of the ultimate crop pattern, therefore, was important in evaluating that requirement. Methods used in deriving a crop pattern for the State as a whole under conditions of ultimate develop- ment are discussed in some detail in Appendix A by Doctor David Weeks, Professor of Agricultural Eco- nomics of the University of California. State-wide acreages of the various crops, as derived by Doctor Weeks, were allocated to the seven major hydro- graphic areas of the State, and, in turn, to hydro- graphic units within the major areas. The assignment of crop areas was based, in general, on known crop adaptability of the soils and on climatic conditions within the various hydrographic areas and units. 48 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Urban and Suburban Areas Generally throughout the State, except in the San Francisco Bay Area and most of the South Coastal Area, the lands to be ultimately devoted to urban and suburban types of development were determined from expected ultimate areal population densities and from forecasts of ultimate urban populations. For this large portion of the State, it was assumed that ultimate urban development will occupy the same general local- ities as at present, but that present land vacancies will be filled and population densities will be increased. It was considered probable that some urban encroach- ment will occur on presently irrigated or irrigable lands, as Well as on nonirrigable lands. The locations of such future encroachment, however, were not spe- cifically predicted nor was the irrigable area reduced to allow for such encroachment. Detailed studies of land use, available undeveloped land, and present and anticipated densities in the metropolitan centers in and around San Francisco, Los Angeles, and San Diego, indicated that the ulti- mate population will be approximately 300 per cent greater than at present under a saturated condition of development. It was assumed that the same ratio of population growth under ultimate conditions was generally applicable to urban areas throughout Cali- fornia. Following this assumption, the 1950 popula- tions of present urban centers, as determined by the federal census, were increased by 300 per cent in order to estimate probable ultimate populations. Present areal population densities were computed from available data, and urban densities were in- creased to 10 persons per acre under ultimate condi- tions of development, except for cities in the Central Valley Area where it was assumed that population densities will ultimately increase to 15 persons per acre. Water requirements under ultimate conditions of population density were estimated on the basis of land areas and total population residing therein. In those hydrographic units where irrigable land is relatively undeveloped at present and where urban development is negligible, the ultimate urban land area was estimated to vary in accordance with the ultimate irrigable area. Studies of presently developed irrigated lands and related urban areas indicated that the urban population will approximate one urban resi- dent per nine acres of irrigated land in the tributary area. Metropolitan Areas Water requirements for urban areas will, in general, va iy with the type of development, that is, residential, commercial, industrial, etc., and consequently more detailed studies were made to project the probable ultimate Land use pattern in the San Francisco, Los Angeles, and San Diego Metropolitan Areas, and in most remaining urban areas in the South Coastal Area, than were made in other urban areas of the State. Such emphasis was necessary because of the relative importance of the large metropolitan centers in determination of future water requirements. Within the defined boundaries of the San Fran- cisco Bay, Los Angeles, and San Diego Metropolitan Areas, it was assumed that under conditions of ulti- mate development all suitable land will be occupied by a balanced urban economy. The suitability of the land for urban purposes was determined largely from topographic considerations, although climatic factors influenced the determination in a feAV instances. The proportions of the several broad classes of urban development, including residential, commercial, indus- trial, parks and institutions, etc., were projected on the basis of present trends within the respective met- ropolitan areas and from historic experience in older communities in other parts of the country. In that part of the South Coastal Area outside of the Los Angeles and San Diego Metropolitan Areas, similar methods and criteria were utilized to deter- mine probable ultimate urban and suburban develop- ment. It was assumed that future growth of this nature will be generally adjacent to and in extension of presently established urban centers. Coastal areas bordering on the Pacific Ocean were assumed to be generally suitable to recreational development in the future in accordance with the well established present trend. Other Water Service Areas The remaining lands of California, not otherwise classified as either irrigable, urban, or metropolitan under ultimate conditions of development, were as- sumed to be utilized eventually for miscellaneous pur- poses requiring a limited water service. It is believed that such land use will be generally sparse, scattered, and minor in extent even when the State is fully de- veloped. Types of land use contemplated for other water service areas include residences, both seasonal and permanent, recreational developments, industrial plants in isolated locations, etc. Other water service areas comprise groupings estab- lished with reference to elevation and existing major jurisdiction and are, respectively, the lands above an elevation of 3,000 feet, lands below that elevation, lands within national forests, parks, and monuments, and those outside the boundaries of such establish- ments. It was assumed that lands included within other water service areas above the 3,000-foot eleva- tion will be inhabited only during the summer months, and will require water service only during that por- t ion of the year. METHODS AND PROCEDURES 49 TECHNIQUES FOR DETERMINING LAND AREAS Acreage included within the various types and classes of land and land use, as delineated on maps and aerial photographs, were obtained either by plani- metering the delineated areas or by the cutting and weighing of maps. Generally, field delineations of land areas made on aerial photographs were transferred to a base map prior to measurement of areas. Plani- metering of areas was done in cases where areas were measured directly on the aerial photographs, and, in some instances, for measuring small parcels of land delineated on maps. Acreage determination by the cutting and weighing of maps was the method generally used for the pres- ent bulletin. In this method, a print of the area to be measured, together with a control of known area, is made on ozalid intermediate material, a high qual- ity vellum paper of uniform weight. Land areas for which acreage is to be determined are cut from the print. All areas cut from the print, as well as the control, are weighed on a precision balance to the nearest one-tenth milligram and the gross area deter- mined in accordance with the weight. Detailed cut- tings are then made from the gross area, and separate weighings are made of subareas or groupings of sub- areas in accordance with the data desired. The control is also weighed intermittently during this process in order that changes in the moisture content of the vellum are accounted for in the computation and as- semblage of acreages of the desired classification. Con- version of weights of land areas to actual acreages is made by multiplying the weights of individual areas, determined between weighings of the control, by the ratio of the control area to the average weight of the control at two successive weighings. DETERMINATION OF UNIT VALUES OF WATER USE Detailed investigations and studies were made to determine appropriate unit values for irrigation use of water throughout California, and for urban use of water in the three large metropolitan areas in and around San Francisco, Los Angeles, and San Diego. The unit values of urban water use in most of the remaining portions of the State were derived mainly from records of water agencies serving many of the smaller cities of the State. Unit values of water use used for other water service areas were generally based on records and estimates furnished by authori- tative agencies. Irrigation Water Use A comprehensive study was made of available ex- perimental data on consumptive use of irrigation water, existing records of irrigation deliveries, and return flows of water, as secured from irrigation dis- tricts and other public and private agencies. Investi- gation was also made of prevailing irrigation practices in the several parts of the State. The method which was developed for determining the unit values of consumptive use of irrigation water provided a work- able standard for derivation of unit values over a wide range of climatic conditions. The method was generally applicable throughout California, and is re- ferred to as the "general method" in this bulletin. The specialized cultural and irrigation practices for a few crops, such as rice, winter-grown potatoes, and grain, appreciably influence the consumptive use of water by these crops. Cultural and irrigation prac- tices for many crops grown in the Sacramento-San Joaquin Delta also differ considerably from those used to produce the same crops in other parts of the State, and affect unit values of consumptive use to such an extent that they could not be evaluated readily by the general method. For such exceptional situations of cultural and irrigation practice, unit values of water use by irrigated crops were derived by so-called "special methods" of analysis. Largely on the basis of judgment, it was assumed for most of the State that the unit seasonal value of consumptive use of water applied to farm houses, out- buildings, and surrounding farm lots averages 0.5 foot of depth. The consumptive use of precipitation on such farm lots was estimated to be the same as that for native vegetation. In many parts of California where climatic condi- tions permit, it is the practice to grow more than one irrigated crop on the same land in a single season. For such areas the unit values of consumptive use of water were adjusted to reflect the resultant increase in water use. In the methods later described, these in- creased unit values of consumptive use were computed by lengthening the crop-growing period to permit the maturing of the indicated number of irrigated crops. Verification of the results obtained by the applica- tion of the derived unit values of consumptive use of water to a given pattern of land use was made by applying these unit values to actual crop patterns in those areas of California susceptible of complete hy- drologic analysis. In these cases the total seasonal consumptive use of water during a mean period of water supply and climate, as derived by application of the computed unit values, compared favorably with the difference between the measured inflow and out- flow of water in the test areas. It is anticipated that the unit values of consumptive use of water estimated for this bulletin will be used in connection with long-range water resource plan- ning. The values expressed, therefore, are those that would occur under mean conditions of water supply and climate, and represent the average consumptive use of water when an adequate water supply is avail- able to produce optimum crop yields. 50 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA General Method. For most of California unit sea- sonal values of consumptive use of applied water and of precipitation for each of the irrigated crop groups were estimated by a method developed mainly by Harry F. Blaney and Wayne D. Criddle of the Soil Conservation Service of the United States Depart- ment of Agriculture. However, the basic method of these authorities was modified somewhat to meet the special needs of the present studies. The general method expresses, by means of the for- mula U = KF, the relation between consumptive use of water, average temperature, and daylight hours in a given area. Consumptive use is established from experimental data or from measured values of use of water. Monthly average temperatures and monthly per cent of annual daylight hours are secured from published data from the U. S. Weather Bureau. Other factors, such as humidity, soil depth and quality, and wind movement, which are known to affect Avater use, are neglected in the correlation, due to the lack of adequate data except for a relatively few localities. The effects of these unevaluated items, however, are contained in the empirical coefficient ' ' K . ' ' The first step in the general method for estimat- ing the seasonal consumptive use of water by each crop is to divide the season into two periods which are termed the "cultural period" and the "noncul- tural period." The former period varies with cadi crop, and generally comprises the irrigation season and the growing season of the crop. The noncultural period comprises the remainder of the season. Gen- erally, during this latter period the annual crops have been removed and the land is without vegetation, although in many cases, preparation of the land for the next season is accomplished. Deciduous orchards and perennial forage crops in most areas are in a dormant stage during the noncultural period. Thus, the characteristics of consumptive use of water in a given locality are completely different in the cultural period from those in the noncultural period. The comsumptive use of water by a given crop in a given area during the cultural period is expressed in the formula U = KF, where : V = consumptive use of water by the crop, in inches of depth F = sum of the monthly consumptive use factors for the cultural period (sum of the products of mean monthly temperature and monthly per cent of annual daylight hours, or t x p) K = an empirical coefficient t = mean monthly temperature, in degrees Fahr- enheit p = monthly total of daytime hours, expressed as a per cent of the total for the year The "A"' coefficient for each crop is derived by utilizing values of consumptive use of water from data obtained from tank experiments, measurements of field delivery of irrigation water, studies of inflow and outflow of water from irrigated areas, studies of soil moisture depletion on irrigated plots, and from esti- mates based on the experience and judgment of quali- fied experts. The "K" coefficient is determined by using consumptive use values, obtained as above, and corresponding values of the consumptive use factor, "F," in the basic formula. For determination of variance in value of the "Jf " factor, the State was divided into 16 climatic areas, ranging from the low desert region of the Imperial Valley to the cool coastal lands of the northwestern coast. Within each climatic area, values of the "K" coefficient were computed by consideration of all avail- able data pertaining to crops and use of water. The "K" coefficient for various crops was expressed as a percentage of the "K " coefficient for alfalfa in areas for which the greatest amount of data pertaining to these crops was available. The resulting percentage was applied to the "K" coefficient of alfalfa in order to estimate the "7f" coefficient for various crops in areas where sufficient data were not available. During the noncultural period the consumptive use of water in a given unit area is derived by application of appropriate unit consumptive use of water values, which are based on experimental and investigational data, experience, and judgment. The values used in the current investigation, within the limits of avail- able precipitation were : (a) 1 inch of depth of water per month for annual crops or for land without vegetation. (b) 1.5 inches of depth of water per month for land devoted to orchards or vineyards. (c) 2 inches of depth of water per month for forage or cover crops. The total seasonal unit value of consumptive use of water, regardless of source of the water, is the sum of the values obtained from the two foregoing computa- tions applicable to cultural and noncultural periods. To determine the seasonal unit value of consumptive use of applied water, that is, the water provided by means other than precipitation, an estimate of effec- tive precipitation is necessary. Effective precipitation is that portion of precipitation that is consumptively used and does not run off or percolate to ground water. The difference between total seasonal unit value of consumptive use of water and seasonal effective precipitation is that portion of the seasonal consump- tive use provided by application of water to the irri- gated area. Effective precipitation is segregated into three portions for the purposes of evaluation : (a) Precipitation occurring and consumptively used during the cultural period. In Cali- fornia this is generally minor in amount. (h) Precipitation occurring during the noncultural period and consumptively used during that METHODS AND PROCEDURES 51 period. The amount is limited by the pre- viously stated criteria governing consump- tive use of water during this period. (c) Precipitation occurring during the noncultural period and percolating to the root zone of the crop where it is retained for consumptive use during the following cultural period. Computations of unit values of consumptive use of water on land devoted to irrigated cotton in the Cen- tral Valley of California, at latitude 36°, furnish an illustrative example of the general method. Values for mean monthly temperature and precipitation were assumed for purposes of this illustration. The empiri- cal coefficient, "K," which was obtained from experi- mental data, was assumed to be 0.62. The cultural period used for cotton was April through October. In the noncultural period it was assumed that consump- tive use of water is equal to all precipitation up to one inch of depth per month. Special Methods. A description of the methods of derivation of unit values of consumptive use of water by those crops affected by specialized cultural and irrigation practices follows : A. Rice. Irrigation practice in rice culture varies considerably from that followed in the production of other crops. Fields are kept flooded from the time SAMPLE COMPUTATION OF UNIT VALUES OF CONSUMPTIVE USE OF APPLIED WATER FOR LAND CROPPED TO COTTON Cultural Period Adjustments for Effective Precipitation Month April May June July August September. October TOTALS. Mean tem- perature, in degrees F. (0 00.5 67.5 74.7 81.0 79.1 72.9 64 . 2 Percent of annual daylight hours (P) 8.86 9.83 9.84 10.00 9.41 8.36 7.84 Con- sumptive use factor (< X P) 5.36 6.64 7.35 8.10 7.44 6.09 5.03 46.01 ="F' Mean pre- cipitation, in inches of depth 1.00 0.55 0.10 0.02 0.01 0.14 0.53 2.35 Consumptive use of water during the cultural period — U = KF - 0.62 X 46.01 = 28.51 inches of depth Noncultural Period Month Consumptive use of water, in inches of deptli Mean precipitation, in inches of deptli November. 0.79 1.00 1.00 1.00 1.00 0.79 1.71 2.04 1.90 1.82 TOTALS 4.79 8.26 Consumptive use of water during the noncultural period = 4.79 inches of depth Total seasonal consumptive use of water = 28.5 -V 4.8 = 33.3 inches of depth Inches of deptli 10.61 Deductions Precipitation occurring and consumptively used during cultural period . . Precipitation consumptively used during noncultural 2 . 35 4.79 7.14 Precipitation occurring during noncultural period and retained in root zone for use by crop during 3.47 * Available moisture-holding capacity in the root zone equals the depth of the principal root zone, estimated to he approximately 4 feet in this instance, multiplied by the unit moisture-holding capacity of the soil, estimated to be 1.5 inches per foot of depth, yielding a product of 6 inches of water depth in this example. Cultural practice of this crop permits the assumption that the entire root zone would be depleted of moisture prior to the beginning of the noncultural period. Thus, it was assumed that the 3.47 inches of precipitation available from the noncultural period was carried over into the cultural period as soil moisture in the root zone. Determination of Seasonal Consumptive Use of Applied Water Inches of depth 33.3 Deductions Precipitation occurring and consumptively used 2.3 Precipitation consumptively used during noncultural 4.8 Precipitation occurring during noncultural period and retained in root zone for use by crop during 3.5 10.6 22.7 of planting to the time the crop matures, when fields are drained to enable harvesting the yield. Planting usually takes place between April 15 and May 15. the fields are drained the following September and harvested during October. The period used for deter- mination of the consumptive use of applied water was the 5-month period from May through Sep- tember. The volume of irrigation water applied varies con- siderably and is dependent to a large extent upon soil type and availability of water. The gross amount of irrigation water applied is frequently greatly in excess of the consumptive use since the maintenance of a small flow in the ponds facilitates the control of fungus and water plants and enhances the crop yield. Existing cultural practices indicate that satisfactory yields are produced when the return flow, or differ- ence between applied water and consumptive use of applied water, amounts to about one foot in depth on the cropped area. Available data for rice farming areas in the Sacra- mento Valley indicate that the total water applied during the growing season amounts to about 5.4 feet in depth and that the return flow is about one foot in depth. Reliable estimates of deep percolation below the root zone indicate that about 0.3 foot of water is disposed of in this manner. The unit seasonal value 52 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA of consumptive vise of applied water is therefore about 4.1 feet in depth, and that value is used in estimates of water requirements for the present study. The value of consumptive use of applied water, as determined above, applies principally to those areas in the Sacramento Valley for which data were avail- able. For those areas, it was estimated that an average depth of 0.2 foot of rainfall occurs during the cul- tural period. For others areas where the precipitation differs significantly from the above value, the unit volume of consumptive use of applied water was adjusted accordingly. Noncultural period consumptive use of water on rice land was estimated to amount to one inch of depth per month, when that amount of water is avail- able. On the basis of an assumed 3-foot depth of principal root zone and 1.5-inch depth of effective moisture-holding capacity per foot of soil depth, it was estimated that 4.5 inches of soil moisture is re- tained from winter precipitation and carried over into the growing season, when it is consumptively used. These two items, plus the cultural period precipita- tion and consumptive use of applied water, were taken to equal the total seasonal consumptive use of water by rice lands. B. Winter-grown Hay and Grains. Small grains, such as barley, oats, and wheat, threshed for grain or cut for hay, are grown extensively throughout California. Unit values of water use by irrigated crops of this type during the summer months were estimated by the previously described general method. Hay and grain crops, however, are also grown during winter months by specialized cultural practices. Expe- rience indicates that, in general, when the depth of seasonal precipitation is approximately 17 inches or more, normally distributed throughout the season, these crops can be satisfactorily grown without irri- gation. In some areas, however, precipitation is not sufficient for this purpose, and the available winter moisture must be supplied by irrigation. Winter- grown grain is planted in the fall, matures during the winter months, and is harvested in June and July. By inspection of monthly precipitation records in a zone of 17-inch depth of mean rainfall, it was ob- served thai the amount of precipitation falling during the months from November through April, the cul- tural period I'm' winter hay and grain, averages about 1.") inches of depth. It was assumed that all of this winter precipitation is consumptively used in matur- ing the crop, and that it is adequate in amount for thai purpose. The remaining 2-inch depth of precipi- tation available was considered to be consumed by weed growth or evaporated from the soil during the noncultural period. It was further assumed that in areas where the normal seasonal depth of precipita- tion is less than 17 inches, the supplemental irriga- tion required for maturing winter-grown small grain and hay is measured by the difference between the actual November-through-April precipitation and a depth of 15 inches. C. Winter-grown Potatoes. In the southern San Joaquin Valley the climatic conditions are such that potatoes can be grown during the winter months, thereby meeting favorable marketing conditions. Planting times vary with locality from late Novem- ber through February, and the crops mature in May and June. Unit values of use of water by winter- grown potatoes were estimated from results of studies of prevailing cultural and irrigation practices. The three months from March through May were taken as the average cultural period. A study of avail- able data on water use for irrigation of potatoes in- dicated that an average depth of 30 inches of irriga- tion water is applied. Based upon the available in- formation, it was estimated that the efficiency of such irrigation application averages approximately 50 per cent. Therefore, the seasonal depth of consumptive use of applied water for winter-grown potatoes, based upon these figures, was estimated to be 15 inches. The average depth of precipitation during the cultural period was estimated to be about 2 inches, all of which is estimated to be consumptively used. A depth of 17 inches, therefore, was taken as the total con- sumptive use of water during the three-month cul- tural period. Consumptive use of water during the remainder of the season was taken as equal to normal precipitation, all of which was assumed to evaporate from the soil or transpire and evaporate from weed growth. D. Crops Produced in Sacramento-San Joaquin Delta. Unit values of consumptive use of water by crops grown in the Sacramento-San Joaquin Delta were based chiefly on data from experiments with growing vegetation in tanks in the delta area. These experiments were conducted by the United States Department of Agriculture in cooperation with state agencies, over a period of six years prior to 1931. A summary of the monthly and seasonal unit values was published in Bulletin No. 26, "Sacramento River Basin," Division of Water Resources, 1931. In order to evaluate the seasonal depth of consump- tive use of applied water in the Delta, estimates of the average depth of precipitation consumptively used were subtracted from the total seasonal unit values of consumptive use of water. All noncultural period con- sumptive use of water was assumed to be provided by precipitation, and all precipitation occurring during the cultural period was assumed to be consumptively used. The depth of precipitation carried over into the cultural period in the root zone was estimated to aver- age approximately two inches per foot of soil depth. The unit value of consumptive use of water by land in the Delta devoted to irrigated pasture was com- puted as previously set forth in the description of METHODS AND PROCEDURES 53 general methods followed in the remainder of the State. Urban and Suburban Water Use Unit values of water use in urban and suburban areas of California, other than in the San Francisco Bay Area and most of the South Coastal Area which are discussed in the following section, generally were estimated from records of present deliveries of water. Available data from private and public water serv- ice agencies were utilized in developing appropriate unit values of water use. Although there are large variations in per capita water deliveries to various cities throughout the State, analysis of available records discloses no firm trends in the amount of the deliveries as related to metered or unmetered water service, or as related to costs of filter to the consumer. More important factors in this respect seem to be the climatological characteristics of the several areas, the abundance or scarcity of water, and the nature and habits of the communities. For these reasons, unit values of water use based on recorded deliveries in cities generally were assigned to adjacent or nearby urban and suburban areas with similar water-using characteristics, where data on deliveries Avere not available. Limited available information on the quantity of sewage outflow from urban and suburban areas indi- cated that, on the average, about 50 per cent of the water production for a city is discharged as sewage. It was assumed, therefore, that in the Central Valley and Lahontan Areas, urban and suburban consump- tive use of applied water is equal to one-half of the quantity of water delivered to the area. In all other areas, sewage is generally discharged to the point of final disposal without opportunity for re-use. In these areas, the gross delivery was taken as both the con- sumptive use and the gross requirement for water in urban and suburban areas. Past and present records of water deliveries to urban areas in California indicate that in recent years there has been an increase in per capita requirement for water, and that the trend is continuing. Part of this increase may be credited to more liberal use of water in households and gardens. In this connect ion a substantial part undoubtedly results from develop- ment of modern water-using household appliances, such as garbage disposal units and automatic washers. In some communities, also, an increasing industrializa- tion has raised per capita values of water use. To ac- count for this increasing use, the probable ultimate unit values of water deliveries to urban and suburban areas generally were increased 10 per cent over pres- ent values. Use of Water in Metropolitan Areas For the three major metropolitan areas of the State, in and around San Francisco, Los Angeles, and San Diego, as well as for most of the remaining urban areas in the South Coastal Area, unit values of water use by each of the principal types of urban land use were estimated by a sampling procedure. In this procedure, an inventory was made of meas- ured water deliveries in sample areas representative of each urban type. For irrigated lands within the metropolitan areas the "general method" of deter- mining unit values of consumptive use of water was employed. Evaluation of unit water use by urban types in the foregoing areas was generally based on the as- sumption that water deliveries to urban consumers constitute an approximate equivalent measure of con- sumptive use of applied water. This follows from the fact that in most of the areas sewage is presently dis- charged to the ocean, and for purposes of inventory may be considered to be wasted or consumptively used. Exceptions to this general assumption were made in those unsewered absorptive portions of the South Coastal Area, Avhere due allowance was taken of return flows from sewage. In the sampling procedure, the sample areas se- lected usually consisted of single blocks or a number of contiguous blocks devoted to one type of land use, and chosen so as to be representative of conditions in the area. The total delivery of water to a given sample area for a recent year was determined by adding all the individual metered deliveries as ob- tained from records of the water agency serving the area. The net acreage of the sample area was deter- mined from assessors' plats or other maps of suitable scale. The unit value of water delivery was obtained by dividing the total delivered water supply by the net area of the sampling, excluding streets. The total acreage sampled for each type of land use varied with the indicated range of unit values of Avater delivery. Industrial deliA r eries of Avater varied so Aviclely, depending upon the industry and the locale, that in order to obtain an average for all industries it Avas necessary to extend the sampling surveys to the larger areas devoted almost entirely to industry. These included the Vernon, Terminal Island, and other industrial areas near Los Angeles and the highly industrialized Emeryville area in Oak- land. Additional extensiA'e suiweys were made to de- termine the unit value of water deliveries to each of a number of major industries throughout the San Francisco Bay and Los Angeles Areas. Probable ultimate unit values of water deliveries in the metropolitan areas usually were estimated by adjusting the present unit values as determined by the sampling procedure. The adjustments were based, insofar as possible, upon indicated trends in unit water requirements for each of the different types of urban land use. 54 WATEE UTILIZATION AND REQUIREMENTS OF CALIFORNIA Use of Water in Other Water Service Areas Estimates of unit values of water use in those present or future water service areas of California not classified as either irrigated, urban and suburban, or metropolitan, were based largely on records or esti- mates of present water delivery. By the nature of the activities involved, water utilization in most of the other water service areas is not adaptable to areal classification, and the unit values of water use con- sisted of per capita or unit of production values rather than as per acre values. The United States Forest Service prepared esti- mates of unit values of water use for recreation, in- dustries, grazing, pollution abatement, esthetics, etc., within the national forests. These values were based on measured deliveries of water in some instances, but to a large extent were estimated from experience and judgment. Similar estimates were prepared by the National Park Service and by the State Division of Beaches and Parks for areas under their respective jurisdictions. Estimates of unit values of water use by permanent military establishments, when so classified, were based on records of water deliveries and populations of the establishments obtained from military authorities. The same values were utilized for both present and probable ultimate conditions. Use of water in the lumber industry was estimated on the basis of units of production. Such use does not occur in all hydrographic areas of the State, and varies in amount in the areas in which it does occur. The principal purposes for which water is used in the heavily forested North Coastal Area are in the production of wood pulp products and in evaporation from mill ponds. Based on data available from the industry, the consumptive use of water in this area for these purposes is estimated to average about 25 acre-feet per million board feet of timber harvest. The mining industry, while requiring an adequate supply of water in relatively isolated locations, gen- erally has a minor consumptive use. Information on use of water by the industry is scant and the esti- mates in this bulletin are based on an assumed gross requirement in the various hydrographic areas. Much of the ore which is mined is transported to refineries located in or near urban centers, and the water re- quirements related to refining are included in the gen- eral industrial requirements for such urban areas. In Hi' North < loastal Area, gold refining involves the use of about 1.5 acre-feet of water per ounce of gold pro- duced, and this value was used in estimating require- ments for other areas. Very little of this water is used consumptively, hut the disposal of the highly toxic waste requires treatmenl to prevent stream pollution. For this reason, and because of the relatively minor am. nints of water involved, the total use of water by the mining industry was treated as a consumptive use in the determination of ultimate water requirements. A considerable amount of water has, in the past, been nonconsumptively used in the production of gold by hydraulic methods and by dredging. Restric- tions now placed on such operations, in order to pre- vent stream pollution and destruction of land, indi- cate that in the future placer gold will be produced by less destructive methods and that smaller amounts of water will be required. In general, the water consumed in the propagation and preservation of fish and wildlife is so minor in extent that the actual consumptive use was not com- puted. Minimum stream flow requirements for the protection of fish life at specified points on many streams of the State were estimated by the California Department of Fish and Game. These estimates are listed in Appendix F. Wildlife refuges on the valley floor of the Central Valley, and the Tule Lake. Lower Klamath Lake, and smaller refuges in other parts of the State use water consumptively in an amount equal to evaporation from the ponded areas established to attract game. In these cases, the evaporation was esti- mated from available data and was included in the water requirements of the hydrographic areas con- cerned. As has been stated, it was assumed that all lands of the State will be included in one of the types of water service areas under conditions of probable ultimate development. In such water service areas outside of the previously described specific types of develop- ment, unit values of water use were expressed on a per capita basis, assumptions being made as to the densities of ultimate population in the various parts of the State. For those lands in the other water service areas above an elevation of 3,000 feet it was assumed that occupancy would be limited to a few months of the year, thus reducing the effective sea- sonal per capita value of water use. Corresponding lands below 3,000 feet in elevation were assumed to be occupied for longer periods of the year. Consump- tive use of precipitation was not estimated for other water service areas since it was not considered as meeting any portion of the water requirements. DETERMINATION OF WATER REQUIREMENTS In general, the estimates of present and probable ultimate requirements for water were derived by applying unit values of water use to the areas of each type of land use and dividing by the appropriate efficiency factor. In some instances, requirements were separately determined and the resultant effi- ciencies estimated to the nearest five per cent. The amounts of most nonconsumptive requirements for water are not readily determined except as they relate to actual water development projects, and can he evaluated only with consideration to other require- ments for water at the time future projects are im- METHODS AND PROCEDURES oo plemented. For this reason, nonconsumptive water requirements are discussed only generally in this bulletin. Present Requirements The present irrigation requirement for water in each hydrographic unit was estimated as the sum of the products of the appropriate unit values of con- sumptive use of applied irrigation water and the areas of the various irrigated crop types, divided by an estimated water service area efficiency, or by equiv- alent procedure. Present urban and suburban water requirements within hydrographic units other than the South Coastal Area, were estimated as the prod- uct of a unit value of water delivery and the de- termined area of the urban and suburban land use. In the South Coastal Area the urban and suburban requirements were estimated by the procedure de- scribed in the next paragraph for metropolitan areas. For unclassified areas within hydrographic units throughout the State, present water requirements were estimated as the sum of the products of unit values of water delivery and population, units of pro- duction, and other appropriate factors. The total present requirement for water in each hydrographic unit was then taken as the sum of the individual re- quirements for the several classes of water use. Present urban water requirements for hydrographic units of the metropolitan areas in and around San Francisco and San Diego were estimated as the sum of the products of appropriate unit values of water delivery times the areas of the various types of urban land use, multiplied by a factor to account for water losses in conveyance and delivery throughout the water system. Records indicate that such water losses generally vary from about 5 to 15 per cent of the production of the water service agency. However, in estimating urban requirements for hydrographic units of the remainder of the South Coastal Area, including the Los Angeles Metropolitan Area, consideration was given to re-use of a portion of the uneonsumed de- livered urban water in absorptive areas, including consideration of the status of sewage reclamation. Re- quirements for irrigation water in the metropolitan areas were estimated as described in the preceding paragraph. Data were available in many hydrographic units regarding the irrigation efficiency attained by agencies serving portions of each unit. This efficiency was a principal factor in the estimation of water service area efficiencies for irrigated lands. The estimated consumptive use of applied irrigation water in in- dividual areas was divided by the quantity of water delivered to those areas in order to provide an index by which the water service area efficiency of the unit could be estimated. In those hydrographic units where such data were available from several agencies. the water service area efficiency for irrigated lands was evaluated by consideration of the total data avail- able. In units where this information was not avail- able, water service area efficiencies as determined for other hydrographic units in the same general locality and with similar water-using characteristics were ad- justed in accordance with experience and judgment. Determination of water service area efficiencies for irrigated lands included consideration of many per- tinent factors, including: the amount of re-use of re- turn flow from irrigation within the area, irrecover- able losses of water resulting from operation of the conveyance and distribution system, flushing water required to maintain proper salt balance in soils of the area, and topographic and geologic conditions which affect the use and application of irrigation water. Ultimate Requirements Estimates of water requirements under conditions of probable ultimate development were derived by methods generally similar to those employed for pres- ent conditions. The principal difference in the methods generally used in estimating the requirements for ir- rigated lands was the consideration given to geologic factors that will be of primary importance under con- ditions of complete irrigation development. These factors include the existence, extent, and type of ground water basins within a hydrographic unit, and their position with relation to sources of water supply for the unit and to other hydrographic units. The first step in determination of the ultimate ir- rigation requirement for water in many hydrographic units was to divide the unit into subareas, largely on the basis of topographic and geologic conditions. Ir- rigable lands within these subareas were segregated, on the basis of geological conditions, into lands over- lying free ground water basins and those overlying confined ground water basins or nonwater-bearing materials. In the former case, relatively high water service area efficiencies were assumed, while in the latter case the water service area efficiency was esti- mated to be somewhat lower. Consideration was given to available data and experience regarding irrigation practice in comparable existing fully developed ir- rigated areas in developing estimated ultimate ef- ficiencies. For each hydrographic unit a weighted average water service area efficiency was then derived, on the basis of previously computed subarea efficien- cies of the irrigated lands respectively overlying ab- sorptive and nonabsorptive materials, and considering re-use of return flow from one subarea by another subarea which is topographically situated and geo- logically adapted to use of the return flow. Return flows of irrigation water were thus routed through the entire hydrographic unit to determine the require- ment for irrigation water in the unit as a whole. The method was modified somewhat in detail in its appli- 56 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA cation to hydrographic units of the South Coastal Area. An extension of this method was employed in de- termination of the ultimate irrigation requirement for water in certain of the hydrographic units on the floor of the Central Valley where considerable infor- mation on irrigation water use and return flow is available. Nonabsorptive irrigated lands were divided topographically into two parts, the higher of which was assumed to receive water to meet its full irriga- tion requirement from either surface or ground water sources independent of return flow from within the nonabsorptive area. The lower portion of the non- absorptive area was assumed to receive a portion of its irrigation water supply from return flow of ap- plied water on the higher portion. The basis for de- termination of the degree to which return flow was utilized was the data on water use collected over the past quarter century in the Sacramento and lower San Joaquin Valleys. In hydrographic units, other than those in the San Francisco Bay and South Coastal Areas, the probable ultimate urban and suburban water require- ment was estimated as the sum of the products of unit values of water delivery applied to the forecast ultimate areas of the urban and suburban class of land use. Probable ultimate urban requirements for water in hydrographic units of the San Francisco Bay and South Coastal Areas, including the metropolitan areas, generally were estimated as the sum of the products of appropriate unit values of water delivery applied to projected ultimate areas of the several major classes of urban land use, adjusted to account for water losses in conveyance and distribution throughout the water system. In the South Coastal Area consideration was also given to re-use of water in minor unsewered areas overlying absorptive ma- terials. Ultimate water requirements for the remain- ing lands of the State, other than those classified as irrigated or urban and suburban under ultimate conditions of development, were estimated by apply- ing appropriate unit values of water delivery to the forecasted population, units of production, and other appropriate factors. The total ultimate requirement for water in each hydrographic unit was then the sum of the individual requirements for the several classes of water use. Usable return flow of applied water was considered to be a part of the water supply available in evalu- ating total ultimate water requirements of the major hydrographic areas of the State. PROBABLE ULTIMATE SUPPLEMENTAL WATER REQUIREMENTS For the purposes of this bulletin, probable ulti- mate supplemental water requirements were evalu- ated as the difference between presenl and probable ultimate requirements for water, plus the present supplemental water requirement in those areas expe- riencing an existing deficiency. The possible additional yield of existing water supply development works over the present water requirement of the area served, was not credited to reduction of the ultimate supple- mental water requirement, except for the developed water supplies allocated from the Friant-Kern, Ma- dera, and Contra Costa Canals. The difficulties inher- ent in defining and determining accurately the amount of present surplus yield, and in allocating such sur- plus to specific water service areas prior to completion of a comprehensive ultimate plan for water supply development and utilization, made the extensive yield studies necessary infeasible in the present study. Methods employed for estimating present and prob- able ultimate water requirements of hydrographic units have been described. In hydrographic units with a present deficiency in water supply development, standard procedures were utilized to evaluate the present safe yield. In hydrographic units where all or a major part of the present water supply is obtained from surface reservoirs, it was necessary to make operation studies over a critically dry period of years in order to esti- mate safe yields. Adequate information as to these operation factors was frequently lacking and yield studies were based on fragmentary runoff data, reser- voir inflow being estimated by correlation with re- corded or estimated flow of other streams. In many hydrographic units, surface supplies, while adequate during the early portion of the irrigation season, decrease rapidly during the summer and are insuffi- cient for present requirements in the latter part of the irrigation season. In many of these cases, stream flow records were not available and estimates of safe yield were based on runoff estimates made by corre- lation with flow of other streams. In hydrographic units where all or a portion of the water supply is obtained from ground water basins, a complete hydrolo^ie investigation is neces- sary to determine present safe ground water yield. Special investigations have been made in the past for only a limited number of ground water basins in California. Complete hydrologic studies for the others were beyond the scope of work for this bulletin. Determinations of safe ground water yield employed in estimating probable ultimate supplemental water requirements for this bulletin must, for this reason. be considered as reasonably approximate evaluations. For the reasons stated, the available data upon which to base estimates of safe yield of the present water supply development were often inadequate, and the resulting estimates of present supplemental requirements are necessarily subject to a margin of error. Determinations of ultimate supplemental water METHODS AND PROCEDURES 57 requirements based thereon, however, are believed to be sufficiently reliable for their principal purpose, which is to develop sufficient information regarding surplus and deficiency in water supply in the various areas of California to permit development of The California "Water Plan. A necessary qualification in evaluating the esti- mated supplemental water requirement for a major hydrographic area, or for a stream basin within that area, is that the total supplemental requirement is not necessarily equal to the sum of the individual supple- mental requirements of the included hydrographic units. This follows from the fact that there is usually opportunity for re-use of return flows from water applied on upstream hydrographic units, thus reduc- ing the supplemental requirement for the major hy- drographic area or stream basin taken as a whole. DETERMINATION OF PROBABLE ULTIMATE WATER REQUIREMENT OF METROPOLITAN AREAS BY POPULATION-SATURATION METHOD In the course of the current State-wide Water Re- sources Investigation it became evident that the esti- mates of probable ultimate water requirement in the San Francisco, Los Angeles, and San Diego Metro- politan Areas are of major significance in planning for comprehensive water resource development in California. For this reason, and in view of inad- equacies inherent in any known method of forecasting ultimate conditions, a supplemental series of estimates of ultimate water requirements was made for the met- ropolitan areas. These estimates were to a large extent independent of those previously described which were based on the land use pattern and unit areal values of water use. The supplemental estimates involved forecasting the probable ultimate population, which was done on an area-saturation basis rather than on one of chronological extrapolation, and fore- casting the ultimate per capita water use on the basis of studies of past and indicated future trends in the various classes of urban water use. The studies of ultimate water requirement by the population-satura- tion method were undertaken with the objective of evaluating in general terms the reasonableness of the forecasts by the land use method. The first phase of the population-saturation method of estimating ultimate water requirements was to forecast the ultimate population of each metropolitan area. Basically, this was clone by multiplying esti- mated net ultimate urban areas by estimated popula- tion density values. In the San Francisco and San Diego Metropolitan Areas the net ultimate urban area was defined as the total habitable area, as determined by the previously described land classification surveys. decreased by forecast residual agricultural areas, nonwater-using industrial areas, and by the areas of heavy industry. In the Los Angeles Metropolitan Area, however, the industrial land use was not sep- arated from the other types, while agricultural use was only accounted for indirectly. The net ultimate urban area in the San Francisco and San Diego Met- ropolitan Areas was segregated between valley and mesa lands and foothill lands. In the Los Angeles Metropolitan Area this subdivision was omitted. The second phase in the population-saturation method was to forecast the ultimate per capita deliv- ery of water for the several classes of urban water use in each metropolitan area. This was accomplished by study of recent trends in per capita values of delivery of water. The per capita deliveries were then pro- jected to their probable ultimate values on the basis of the present trends and considered assumptions as to the nature of future urban development. The final phase in the method was to multiply the forecast ultimate population by the assumed per capita values of water delivery in the several classes of water use. The sum of the products was adjusted for conveyance and delivery losses, resulting in the estimated total ultimate urban water requirement for each metropolitan area. A description of the population-saturation method as it was developed and applied in the San Francisco Metropolitan Area will serve to illustrate the basic procedures involved. The applications of the method in the Los Angeles and San Diego Metropolitan Areas varied from the described procedure in detail, partly because of differing characteristics of the areas, and partly because of simultaneoiis independent develop- ment of the procedures by different investigators in each of the areas. In the San Francisco Metropolitan Area the ulti- mate habitable area in each county, obtained from the land classification survey, was segregated into those parts with a present high degree of development and those relatively undeveloped. This was accomplished on the basis of population densities in appropriate subdivisions. These subdivisions were formed by as- sembling groups of voting precincts or census tracts having similar and, insofar as possible, homogeneous characteristics as to classes of present land use, par- ticularly with regard to the several residential types. Consideration was also given to commercial, munic- ipal, and industrial classes of land vise. Aerial photographs of each subdivision in relatively highly developed areas were examined in detail, with- out regard to topography, to determine percentages of occupancy and vacancy in the area under consid- eration. Present effective population densities within the subdivisions were next estimated by dividing the aggregate population of each subdivision by the total area actually occupied. 58 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA The next step was to forecast the proportion of the area of each subdivision that will ultimately be occu- pied. In this step, consideration was given to the probable effects of topography on urban develop- ment, the present trend toward tract-type housing construction, and other pertinent factors. The areas to be occupied by nonwater-using activities and heavy industry were excluded. Segregation was also made between valley and mesa lands and foothill lands to obtain patterns characteristic of differing topographic conditions. The estimated ultimate population of each subdivision was obtained by applying effective popu- lation densities to the areas actually to be occupied by urban development, Over-all effective population density factors were determined separately for valley and mesa lands and for foothill lands. This was done by combining the ultimate population and area fore- casts for the various subdivisions in accordance with their topographical classifications. A determination was made for each county in the San Francisco Metropolitan Area of those portions of the present relatively undeveloped area which are suitable for future urban development. This was done by study of topographic maps on the basis of voting precincts, census tracts, or townships. The considera- tions involved included topographic conditions, rela- tive isolation from present urban centers, and other pertinent factors. Areas ultimately to be devoted to agriculture and industry were excluded, and a divi- sion of the net urban area was made between valley and mesa lands and foothill lands. The over-all effec- tive population density factors for balanced urban communities, determined as described in the preced- ing paragraph, were applied to the portions of each county determined to be suitable for future develop- ment. This resulted in forecasts of probable ultimate urban population for the relatively undeveloped por- tions of the various counties, which were added to the estimates derived for those portions of the counties at present relatively highly developed to arrive at l lie estimate of the total ultimate urban population For the San Francisco Metropolitan Area. The estimate of probable ultimate per capita water use in the San Francisco Metropolitan Area was based largely on records of annual delivery of water to individual consumers by 10 major public and pri- water service agencies in the area over a period extending from 1940 through 1950. These data were differentiated by the agencies according to several classes of urban water use, including residential, commercial, municipal, and industrial. The standards of classification varied somewhat among the several agencies, and the records were reconciled as required to permit combining of the data from the different agencies. Consideration was given to the use of large amounts of water by certain industries utilizing pri- vately developed supplies, in addition to the data ob- tained from the water service agencies. Estimates of the total population served by the respective water service agencies were made for years corresponding to the available data on water deliveries. The total annual use of water was divided by the corresponding total population served to estimate the per capita use of water for each class of urban water service. These annual values were plotted so as to define recent trends in per capita use of water. The foregoing data indicated a fairly constant rate of per capita use of water with regard to commercial and municipal uses. In determining the probable ulti- mate water requirement for these two classes the in- dicated present values were used. A prominent up- ward trend was apparent in the per capita use of water for residential purposes. On this basis, a sub- stantial increase over the present value was forecast for ultimate residential per capita use of Avater. While no significant trend in per capita industrial use of water was noted, on the basis of an indicated over-all present deficiency in the level of industrial production in California, and in the San Francisco Bay Area in particular, a substantial future increase in per capita industrial use of water was predicted. The final step in the population-saturation method was to total the estimated values of ultimate annual per capita use of water for the several classes of urban water use, and to apply the total to the esti- mated ultimate urban population to obtain an esti- mate of total annual ultimate urban use of water in the metropolitan area. The estimate of total use of water was increased by a factor representing esti- mated distribution and transmission losses, based upon the experience of water service agencies in the San Francisco Bay Area. This final value derived was the estimate of probable ultimate annual urban water requirement for the San Francisco Metropoli- tan Area. CHAPTER III NORTH COASTAL AREA The North Coastal Area, designated Area 1 on Plate 8. constitutes the northwestern portion of the State between latitudes 38° and 42° N. Its shape is roughly that of a triangle, the shorter leg lying along the Oregon border for about 180 miles on the north and the longer leg along the Pacific Ocean for some 270 miles on the west. Within its boundaries are the entire counties of Del Norte, Humboldt, Trinity, and Mendocino, and parts of Siskiyou, Modoc, Glenn, Lake, Sonoma, and Marin Counties. Among the prin- cipal incorporated cities are Santa Rosa, Eureka, Ukiah, Fort Bragg, Areata, Ilealdsburg, and Yreka. The topography of the North Coastal Area is char- acterized by a predominance of mountainous terrain, and nearly one-half of the area lies within national forest boundaries. The major portion of the national forest land lies in the Cascade Mountains, Coast Range, and Klamath Mountains north of Mendocino County. In order to facilitate the present studies, the North Coastal Area was divided into 16 hydrographic units, which, with two exceptions, are identical with the drainage basins of the principal streams. Two basins, those of the Klamath and Eel Rivers, were divided into upstream and downstream hydrographic units, while the principal tributaries of these two streams were also considered as separate hydrographic units. The 16 hydrographic units and their areas are listed in Table 2 and their boundaries are shown on Plate TABLE 2 AREAS OF HYDROGRAPHIC UNITS, NORTH COASTAL AREA Hydrographic unit Reference number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name Tule Lake Shasta Valley Scott Valley Upper Klamath Trinity Klamath Rogue Del Norte Redwood Creek Mad River Upper Eel Humboldt Mattole Mendocino Coast Russian River Bodega APPROXIMATE TOTAL Acres ,544,000 508,000 423,000 614,000 ,897,000 ,416,000 107 000 456,000 191,000 409,000 ,976,000 565,000 235,000 ,037,000 960,000 165,000 TABLE 3 AREAS OF COUNTIES WITHIN BOUND- ARIES OF NORTH COASTAL AREA County Acres Del Norte 700,000 Glenn 53,800 Humboldt . 2,305,000 Lake 190,000 Marin __ . 95,400 Mendocino 2,247,000 Modoc 753,000 3,270,000 Sonoma _ . 842,000 Trinity 2,047,000 APPROXIMATE TOTAL- 12,500,000 12,500,000 8. Table 3 lists the several counties lying wholly or partly within the North Coastal Area, together with their included acreages. Prevailing northwest winds with heavy fog and moderate temperatures are typical of climatic condi- tions along the northern coast of California. Inland portions of the North Coastal Area characteristically experience a wider temperature range and more mod- erate winds. Precipitation is principally in the form of rainfall, with substantial snow falling in only the higher elevations. The heaviest rainfall in the State occurs in Del Norte County, where a mean seasonal precipitation of about 75 inches of depth has been recorded near Crescent City, and average seasonal values as high as 100 inches have been estimated for locations in the Klamath Mountains. The record at Healdsburg in Sonoma County in the southern por- tion of the North Coastal Area indicates a seasonal mean depth of precipitation of about 40 inches. Pre- cipitation inland from the coast is relatively high throughout most of the higher mountainous areas. However, lower rates are typical of the larger moun- tain valleys and of the northeastern plateau areas. The 17-year precipitation record at Tulelake in Modoc County indicates an average seasonal depth of only about 10 inches. Variation in precipitation from year to year is typified by the 58-year record at Eureka which has a seasonal average depth of 38.34 inches, a maximum of 74.10 inches, and a minimum of 20.72 inches. On the average, approximately 85 per cent of the seasonal rainfall in the North Coastal Area occurs in the months from December through April. It is estimated that the mean seasonal natural runoff of streams of the North Coastal Area is about 28,000,000 acre-feet, or about 41 per cent of that for ( 59) 60 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA the entire State. The greatest single contribution to runoff of the area is made by the Klamath River with a drainage area of approximately 15,700 square miles, one-third of which lies in Oregon. The mean seasonal natural runoff of the Klamth River in Cali- fornia is estimated to be about 11,120,000 acre-feet, or some 38 per cent of the total of the North Coastal Area. Runoff from the coastal streams closely follows the rainfall pattern. Average monthly stream flow during the dry summer months of July, August, and September is less than one per cent of the seasonal total in all coastal streams except the Klamath and Smith Rivers, and in those rivers it is only slightly higher. Shasta and Scott Rivers, draining absorptive interior basins, maintain relatively greater summer flows, with about 15 per cent of the seasonal runoff occurring during the three named summer months. As shown on Plate 4, a total of 18 valley fill areas, which may or may not constitute ground water- basins, has been identified in the North Coastal Area. Appreciable development and utilization of ground water supplies is presently limited to those basins underlying Shasta, Scott, and Butte Valleys, Eel and Mad River deltas, three irrigated areas in the Russian River Basin, and the Dry Creek-Santa Rosa Plains area. The population of the North Coastal Area has more than doubled in the last 50 years. The Counties of Del Norte, Humboldt, Mendocino, Siskiyou, Sonoma, and Trinity had an aggregate population of approxi- mately 110,000 in 1900 and 257,000 in 1950, an in- crease of about 134 per cent. The populations of the principal urban centers, as shown in Table 4, have almost doubled between 1940 and 1950. It may be noted that recent growth in population of suburban areas of the larger communities has been proportion- ately greater than within the city limits. TABLE 4 POPULATION OF PRINCIPAL URBAN CENTERS, NORTH COASTAL AREA 1940 1950 City Within city limils In suburbs Total Will, in city limits In suburbs Total Rosa i 12,600 17,100 3,700 3,200 1,800 ..-.(in i, too ! [Q0 4,800 2,400 3,900 1,300 3,200 900 500 17,400 19,500 7,600 4,500 5,000 2,500 2,300 3,000 17,900 23,100 6,100 3,800 3,700 3,300 1,800 3,200 15,000 5,100 7,500 5,600 .-,.1,1)11 1,700 2,800 1,100 32,900 28,200 13,600 9,400 9,300 5,000 4,600 4,300 Fort Bragg Areata.. _ burg Fortuna-- Yreka.. ._ Lumbering is the outstanding industry in the North i'il Area, with timber products in 1951 valued at aated $175,000,000. Agriculture, the principal r-using industry, is second in importance, with the annual production valued at .+80,000,000 by the 1950 census. The majority of the crops are closely allied with the livestock industry, and alfalfa, pasture, hay, and grain predominate. Irrigated areas have in- creased from 56,000 acres in 1900 to 213,000 acres in 1953. Most of this increase has occurred within the past 20 years. Mining operations provided the incentive for the original water developments in the North Coastal Area. Beginning in 1849-50, ditches were constructed in Shasta and Scott Valleys to divert water for mining purposes. The first recorded use of water for irrigation occurred in 1850 when one of the mining ditches in Shasta Valley was utilized to irrigate agricultural lands. Mining has gradually decreased in importance. At the present time it includes chromite operations at various locations in the Klamath Mountains and the Coast Range, minor mercury production at mines scattered from Sonoma County to the Oregon border, the extraction of pumice in the Glass Mountain area of Modoc County, the production of sand and gravel, and some mining of gold, silver, and manganese. Since about 1900 agriculture has become the principal water-using industry. Numerous private and coopera- tive irrigation developments were constructed, with water supplied by pumping from stream gravels or by direct surface diversion. Many of the larger units have since been reorganized under irrigation district laws. Six present irrigation districts in the North Coastal Area had a total area in 1948 of 36,400 acres, of which 14,411 acres were reported to be under irrigation. Four districts, Montague, Scott Valley, Grenada, and Big Springs, were organized to take over existing irrigation works. Butte Valley and Potter Valley Irri- gation Districts were formed to develop previously unirrigated lands. In 1906 the United States Reclamation Service began construction of the first unit of the Klamath Project in California and Oregon. Drainage and irri- gation of lands surrounding Tule and Lower Klamath Lakes have been continued since that time, until an area of 69,840 acres in California was under irrigation in 1953 within the Klamath Project area. Irrigation from surface storage in the North Coastal Area is accomplished by three large developments and numerous small reservoirs. Clear Lake Reservoir, con- ceived primarily as a flood control basin, also supplies water to a portion of the Klamath Project of the Bureau of Reclamation. Dwinnell Reservoir in Shasta Valley provides water for the Montague Water Con- servation District. The Potter Valley Irrigation Dis- trict utilizes Eel River water, stored in Lake Pillsbury and imported to the Russian River watershed pri- marily for power generation. After passing through the Pacific Gas and Electric Company power plant, the water is diverted for irrigation purposes in Potter Valley. Small water storage developments serve indi- vidual farms and ranches, lumber mills, and mines. Fishing Fleet at Eureka Courtesy Eureka Chamber of Commerce Sawmill in North Coastal Area Courfesy Eureka Chamber of Commerce 62 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA The large available runoff and rugged topography of the North Coastal Area provide conditions favor- able to power generation, but present development in the area consists of only six hydroelectric installations, three of which are under 5,000 kilowatt capacity. This is due to the relatively small industrial and urban power demand within the area and the long transmis- sion distance to urban load centers. Municipal water supplies of the Cities of Eureka and Areata are provided by reservoir storage and ground water pumping. Other communities are served by wells, springs, surface diversions, or combinations of these sources. A compilation of the principal water service agencies in the North Coastal Area is included in Appendix B, together with the number of domestic services and area of irrigated lands served by each agency. The lumber industry has developed as the principal source of income in the North Coastal Area, mainly as a result of the large stand of virgin timber located within its boundaries. Other industrial development, such as food processing and the manufacture of ply- wood and furniture, are related to the area's primary industries, agriculture and forestry. The limiting in- fluences of soils, topography, and short growing season have maintained relatively stable crop patterns in the North Coastal Area, with increases in production re- sulting from irrigation of previously dry-farmed lands. All irrigable land is expected to be developed under ultimate conditions to the same type of crop pattern as at present. Urban areas have developed slowly in the past due to lack of demand for urban services. Much of the recent growth of the larger urban centers has been in suburban areas surrounding existing towns, and growth in many cases has been at the expense of developed agricultural land. The North Coastal Area has a high potential as a recreational area. The vast forested mountain areas, long scenic coast, and the abundance of fish and game make the area an important resort and recreational region. Development of recreational facilities has been greatest in the coastal redwood region and along the lower reaches of the Russian River, largely as a result of close proximity to the densely populated San Francisco Bay Area. The many streams of the North Coastal Area attract sport fishermen from throughout the State, and the coastal waters support an important sport and commercial fishery. As the population of the State increases, it is anticipated thai an increasing demand will be placed upon the recreational facilities of the region. The North Coastal Area is well provided with the resources required to meet this demand, and it is anticipated that the re- sort and lonrist trade will become a major field for de- velopmenl in i he l'ni are. The principal existing use of water in the North Coastal Area is For agriculture. Use of water for do- tic industrial, and power generation purposes is relatively minor. Ultimate demands for water within the area are expected to follow generally this same pattern, with estimated ultimate development pred- icated upon a continued predominantly agricultural and lumber economy. High peak flood flows in an area of low population density and relatively sparse agricultural develop- ment have made flood control measures in the North Coastal Area difficult of justification, although wide- spread flooding of towns and agricultural lands has occurred periodically. It is probable that in the fu- ture adequate flood control works will be constructed in the areas of greatest development. Use of water for recreation is limited to that con- sumed for domestic purposes in resort and recrea- tional areas, evaporation from migratory waterfowl refuges, and to water used for supporting stream flows for maintenance of fish life. These uses will increase as facilities are developed to provide for the recrea- tional needs of the growing population of the State. Available data and estimates pertinent to the na- ture and extent of water requirements in the North Coastal Area, both at the present time and under con- ditions of probable ultimate development, are pre- sented in the following portion of this chapter. PRESENT WATER SERVICE AREAS As a first step in estimating the amount of the water requirement in the North Coastal Area, with the present pattern of land use and under mean con- ditions of water supply and climate, determinations were made of the location, nature, and extent of irri- gated and urban and suburban water service areas. Remaining lands were not classified in detail with re- gard to their relatively minor miscellaneous types of water service, although such water service was given consideration in estimating the present water re- quirement, Irrigated Lands It was determined that under present conditions of development in the North Coastal Area, about 213,000 acres are irrigated in a given year, on the average. This constitutes approximately three per cent of the land irrigated throughout California. Grain and the forage crops, such as pasture, alfalfa, and hay, are the dominant crops due to their adapt- ability to the- soils and the short growing seasons oc- curring throughout most of the area, Truck and or- chard crops are produced throughout the region, but principally in small quantities for home consumption. Although a substantial acreage is planted to vines, this crop is principally dry-farmed. Lands in the Tule Lake and Butte Valley Basins produce quantities of truck, of which potatoes are the principal commodity. In the Tule Lake hydrographic unit potatoes were The Klamath River Courtesy Moulin Studios 64 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA classified separately so as to permit consideration of It is estimated that approximately 4,100 acres in their somewhat higher water requirements. Crops in the North Coastal Area are occupied by farm lots at the Russian River Valley are more diversified, with the present time. These consist of farm buildings and pasture, field crops, orchard, and alfalfa constituting the immediately surrounding areas receiving water the bulk of the irrigated agricultural production. service. mi „ , ., -,■-,-,, ■ <■ P Summaries of presentlv irrigated acreages within The field surveys upon which determinations or ,, XT ,, -, , , . , ,, . . , , '. J XT A . ~ , . . the North Coastal Area by the various crop groups irrigated acreage m the North Coastal Area were , , . m , , _ , „ m ■,, c v , ., , & , & .. , n _ . ,. . . „ ..._ are presented in Tables 5 and 6. Table 5 lists the acre- based were accomplished during the period from 194/ i i i i • -j. i m i_n o i ia i -inro t.1 • -/i • i ages by hvdrographic units, and Table 6 by counties, through 1953 by several agencies with varying stand- J ards and degrees of accuracy. Information regarding Urban and Suburban Water Service Areas the dates of field mapping and sources of data is Tx , , . , ,, , ,... .-•-,.' A i- t\ -n j j.i -i t.1 It was determined that under present conditions contained in Appendix D. Based on the available sur- „ . , , . ,, ^ ,, _. r , , . j , ,, ■ j i j i -n i ■ of development m the North Coastal Area approx- vey data, the irrigated lands were classified into . J . , i, _„„ , , , , , , • ,, • , , ■ ,-. imately 18,500 acres are devoted to urban and subur- various crop groups with a view to segregating those , ,„■,, t-,,i , ■ o ■ ■-, . » r + n +1 e n ban types of land use. hor the most part, business, of similar water use. A list or these groups follows : . , ^ ■ -, ± ■ -, , , • , commercial, and industrial establishments and sur- Alfalfa _ -Hay, seed, and pasture. rounding homes included in this areal classification Pasture Grasses and legumes, other than receive a municipal type of water supply. Areas of alfalfa used for livestock for- urban and suburban water service within each hydro- ao . e graphic unit of the North Coastal Area are listed in Table 7, and within each county in Table 8. It should Orchard _ Deciduous truits and nuts. ^ no t e( i th a t areas shown are gross acreages, as they Vineyard— —All varieties of grapes. include streets and intermingled undeveloped lands „,, , , that are a part of the urban tvpe of community. Hay and gram The cereal grasses, wheat, bar- ley, oats, and rye, harvested Unclassified Areas either as a hay or a seed crop. As has been state ^ rema i n i ng lands in the North Truck crops Intensively cultivated fresh veg- Coastal Area, other than those that are irrigated or etables, including tomatoes, peas, urban and suburban in character, were not classified corn, carrots, potatoes, squash, in detail with regard to present water service. How- bushberries, flower seeds, and ever, of a total of about 12,250,000 acres of such re- nursery crops. maining lands, less than 20,000 acres actually receive Miscellaneous water service at the present time. These relatively field crops Hops, field corn, and sugar minor service areas consist of scattered developments beets. in national forests and monuments, public beaches TABLE 5 AREAS OF PRESENTLY IRRIGATED LANDS WITHIN HYDROGRAPHIC UNITS, NORTH COASTAL AREA (In acres) Hydrographic unit Refer ence number 1 2 3 4 5 6 7 8 9 10 11 12 13 1 l IS ii, Name Tule Lake Shasta Valley Scott Valley Upper Klamath Trinity Klamath Rogue Del Norte Redwood Creek Mad River Upper Eel Humboldt Mattole Mendocino Coast Russian River Bodega APPROXIMATE TOTALS Alfalfa (i,!l()0 10,600 4,200 800 200 100 300 400 100 800 21 inn Pasture 100 1,600 600 1,300 700 9,300 200 I. SI II I 18,600 Im- proved pasture* 7,400 13,900 9,400 1,200 2,600 600 35,100 Mar- ginal pasture* 8,200 7,700 2.100 1,600 600 20,200 Mead- owland* 10,700 4,100 8,200 200 400 23,600 Orchard 100 o o o 2,700 2,800 Truck crops 14,800 100 200 100 400 400 16,000 Hay and grain 57,300 1 ,300 6,900 800 100 800 300 67,500 Miscel- laneous field crops 4,300 100 4,400 Net irri- gated area 106,000 37,600 30.800 4,600 3,400 1,200 100 1,700 800 1,400 1,100 10,500 300 13,300 500 213.000 Farm lots 2,200 800 600 100 100 o 100 200 4,100 In- cluded non- water service areas 3.300 1.200 1,000 100 100 100 100 200 300 0.400 Approx- imate gross area 111,000 39,600 32.400 4,800 3,600 1,300 100 1,800 800 1,400 1,100 10,800 300 13,800 500 223,000 Detailed land use survey data from Klamath River Basin Investigation conducted by the State Division of Water Resources. NORTH COASTAL AREA 65 TABLE 6 AREAS OF PRESENTLY IRRIGATED LANDS WITHIN COUNTIES, NORTH COASTAL AREA (In acres) County Alfalfa Pasture Orchard Truck crops Hay and grain Miscel- laneous field crops Net irrigated area Farm lots Included nonwater service areas Approxi- mate gross area 700 800 3,300 19.300 100 200 2,000 11,700 3,300 10,900 64,500 2.000 3,100 1,800 100 900 200 300 100 8,500 6,200 700 1,000 300 20,400 45,800 1,000 3,400 2,200 13,700 7,300 43,100 136,000 7,100 3.300 100 100 900 2,800 100 100 300 200 1,400 4,300 100 100 2,200 14.100 7,600 Modoc _ . Siskiyou _ 45,400 143,000 7,300 Trinity 3,500 APPROXIMATE TOTALS 24,400 97,500 2,800 16.000 67,500 4,400 213.000 4,100 6,400 223,000 and parks, private recreational areas, wild fowl ref- uges, and other similar recreational activities. Approximately 46 per cent of the North Coastal Area lies within the boundaries of the Modoc, Klam- ath, Trinity, Shasta, Mendocino, and Six Rivers Na- tional Forests. The topography of most of these lands is rough, and the existing development is limited, in general, to timber production and stock grazing. Many small scattered valleys and plateaus in the area are suitable for the production of forage crops. The United States Forest Service reports a total of 18,800 acres of such lands under irrigation, and this acre- age has been included in Tables 5 and 6. Other water service areas in the national forests are those occupied by administration buildings, public camps, picnic grounds, and other tourist accommodations, the total of which contributes only a small part to the total water service area. Historic monuments, and public beaches and parks, all administered by the California Department of Natural Resources, provide additional attractions and conveniences to vacationists who an- nually visit the natural scenic wonders of the North Coastal Area. There are 24 such recreational areas, covering a total of 53,800 acres, along the coast be- tween Sonoma and Del Norte Counties. Water service requirements are minor, consisting of domestic sup- plies to permanently inhabited areas and summer supplies to camp and picnic areas. Similar service is supplied to Lava Beds National Monument, which in- cludes 46,000 acres in Modoc County, and is under the jurisdiction of the National Park Service. Private recreational areas are scattered throughout the North Coastal Area, with the major developments of this type concentrated along the Russian River in Sonoma County. Summary Table 7 comprises a summary of present water service areas within hydrographic units of the North Coastal Area, segregated into irrigated and urban and suburban lands. A similar summary by counties is presented in Table 8. PROBABLE ULTIMATE WATER SERVICE AREAS In order to estimate the amount of water that will be utilized in the North Coastal Area with ultimate land use and under mean conditions of water supply and climate, projections were made to determine the probable ultimate irrigated and urban and suburban water service areas. It was assumed that the remain- ing lands, for convenience referred to as "other water service areas," ultimately will be served with water commensurate with their needs. Irrigated Lands Based on data from land classification surveys, it was estimated that a gross area of approximately 1,058,000 acres in the North Coastal Area is suitable for irrigated agriculture. Other than farm lots and TABLE 7 SUMMARY OF PRESENT WATER SERVICE AREAS WITHIN HYDROGRAPHIC UNITS, NORTH COASTAL AREA (In acres) Hydrographic unit Reference number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name Tule Lake Shasta Valley Scott Valley__ Upper Klamath. . Trinity Klamath Rogue Del Norte Redwood Creek. _ Mad River Upper Eel Humboldt Mattole Mendocino Coast- Russian River Bodega Subtotals- Irrigated lands 1 1 1 .000 39.600 32.400 4,800 3,600 1,300 100 1,800 800 1,400 1,100 10,800 300 13,800 500 223,000 Urban and suburban areas 1,000 1,400 200 200 1,000 400 1 ,300 100 800 900 4,300 1,100 5,600 200 18,500 Unclassified areas receiving water service. APPROXIMATE TOTAL Approximate total 112,000 41,000 32,600 5,000 4,600 1,700 100 3,100 900 2,200 2,000 15,100 1,400 19.400 700 242,000 19,500 261,000 3—99801 66 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA TABLE 8 SUMMARY OF PRESENT WATER SERVICE AREAS WITHIN COUNTIES, NORTH COASTAL AREA (In acres) LTrban Irrigated and Approximate County lands suburban areas total Del Norte ... ._.-._. 2,200 1,400 3,600 Humboldt . . . 14,100 5,900 20,000 Marin.. 100 100 Mendocino,. ._....... 7,600 2,200 9,800 Modoc - - - 45,500 45.500 143,000 3,000 146,000 Sonoma _. . - 7,300 4,900 12,200 Trinity 3,500 1.000 4.500 Subtotals — 223,000 18,500 242,000 19,500 APPROXIMATE TOTAL*. 261,000 certain lands within the gross irrigable area that ex- perience indicates will never be served with water, such as lands occupied by roads, railroads, etc., it was estimated that under ultimate conditions of de- velopment a net area of approximately 869,000 acres will actually be irrigated. Table 9 presents these esti- mates for hydrographic units of the North Coastal Area, and Table 10 for the various counties. The probable ultimate crop pattern for irrigated lands of the North Coastal Area is presented in Table 11. The crop grouping parallels that used in the case of present development except for the added group titled "Vineyard." Since most present vineyards are dry-farmed, this group was of minor importance and not segregated in the case of the present irrigated crop pattern. It is expected to be of greater sig- nificance in the future. Urban and Suburban Water Service Areas It is expected that in the North Coastal Area urban and suburban growth generally will be associated with further development of agriculture, although the tourist trade and scenic attractions will probably in- fluence growth of certain population centers. Increase of population may also be brought about by expansion of present and new industries, particularly those as- sociated with the timber resource. It was estimated that under ultimate conditions of development urban and suburban water sin-vice areas will increase to about 53,000 acres. Urban and suburban types of land use are expected to occupy the same localities as at present, but vacant lands will be filled and densities increased. Additionally, it is probable that encroach- ment will occui' on surrounding lands in an estimated ai nt of about 34,500 acres. For the purposes of the present studies no at tempi was made to delineate the boundaries of such encroachment, nor to deter- mine whal proportion will be Oil irrigable lands. The TABLE 9 PROBABLE ULTIMATE AREAS OF IRRIGATED LANDS WITHIN HYDROGRAPHIC UNITS, NORTH COASTAL AREA (In acres) Hydrographic unit Gross irrigable area Farm lots Included nonwatei service area Approxi- mate Refer- ence number Name net irri- gated area 1 2 3 4 5 Tule Lake Shasta Valley. . . . Scott Valley Upper Klamath Trinity 276.000 1 ll.OIMI 68,700 21,300 22,000 8,000 600 30,500 2,200 29,900 49,900 75,000 4,500 75,800 208,000 41,400 4,600 2,100 1,100 300 300 100 300 300 700 700 900 2,800 500 50,200 34,200 12,500 6,700 5,500 1 .500 100 3,700 400 3,800 6,200 9,000 600 10,500 24,200 5,300 221,000 107,000 55,100 14,300 16,800 6 6.400 7 500 8 9 10 11 12 13 14 15 16 Del Norte . . . Redwood Creek Mad River Upper Eel _. Humboldt . Mattole Mendocino Coast Russian River Bodega, APPROXIMATE TOTALS 26,500 1,800 25,800 13,0110 65,300 3,900 64,400 181,000 35,600 1,058,000 14,700 174,000 869,000 TABLE 10 PROBABLE ULTIMATE AREAS OF IRRIGATED LANDS WITHIN COUNTIES, NORTH COASTAL AREA (In acres) County Gross irri- gable area Farm lots Included nonwater service area Approxi- mate net irrigated area Del Norte 35,000 126,000 14,700 155,000 63,700 450,000 195.000 17,900 300 1,500 100 1,400 1,100 7,100 2,900 300 3,500 16.400 8,100 34,900 7,100 97,500 2,300 4,600 31,200 Humboldt. . 108,000 Marin 6,500 119,000 Modoc _ 55,500 346,000 190,000 Trinity. 13,000 APPROXIMATE TOTALS . _ 1,058,000 14,700 174,000 869,000 estimate of probable ultimate urban and suburban water service areas is included in Table 13. It should be noted that the areas shown are gross acreages, in- cluding streets, vacancies, etc. Other Water Service Areas Remaining lands of the North Coastal Area, not classified as irrigable or urban and suburban under conditions of ultimate development, aggregate about 11,390,000 acres, or 93 per cent of the area. As pre- viously mentioned, it was assumed that ultimately these lands will be served with water in amounts suf- ficient for their needs. No attempt was made to segre- gate these "other water service areas" in detail with regard to the nature of their probable ultimate water service. However, as shown in Table 12, they were NORTH COASTAL AEEA 67 TABLE 11 PROBABLE ULTIMATE PATTERN OF IRRIGATED CROPS, NORTH COASTAL AREA (In acres) Hydrographic unit Alfalfa Pasture Improved pasture* Marginal pasture* Meadow- land* Orchard Vine- yard Truck crops Hay and grain Miscel- laneous field crops Refer- ence num- ber Name Approxi- mate total 1 10,500 14,100 16,700 3,700 3,800 1,100 1,500 2,500 4.500 .-,,11111) 500 500 25,200 1,800 18,000 9,100 19,800 3,500 20,000 45.000 11,600 25,000 28,800 13,700 5,200 8,200 3,fi00 2.2(1(1 2.200 5,000 3,100 2,000 300 II 15,700 10,200 0,900 300 100 500 200 1,000 7,000 500 18,300 500 1,100 12,500 35,000 2,200 400 100 400 400 1.300 3,000 4,000 5,000 80,500 15,100 1 1 ,800 1,800 1,700 500 5,300 20,000 10,500 400 41,400 90,300 18,000 22,300 4.800 600 300 200 6,000 "1,000 2 107,000 3 Scott Valley 55,100 4 5 6 7---. 8 Upper Klamath Trinity . Klamath. - - - - Rogue Del Norte. _. 14,300 16,800 6,400 500 26,500 9 10 Redwood Creek 1,800 25,800 11 13,000 12 65,300 13 Mattole .. 3,900 14 15 Mendocino Coast . 64,400 181,000 16 35,600 APPROXIMATE TOTALS 124,000 185,000 84,500 14,800 33.100 28,100 16,900 51,800 297,000 34,200 869,000 Detailed land use survey data from Klamath River Basin Investigation conducted bj State Divisi if Water Resources. TABLE 12 OTHER WATER SERVICE AREAS UNDER PROBABLE ULTIMATE CONDITIONS, NORTH COASTAL AREA (In acres) Hydrographic unit Reference number Name Inside national forests and monuments Above 3.000-foot elevation HeloM :; ooo-i,,,, i elevation Outside national forests and monuments Above 3.000-foot elevation Below 3.000-foot elevation Approximate total 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Tule Lake.. Shasta Valley Scott Valley Upper Klamath Trinity Klamath . Rogue Del Norte Redwood Creek Mad River Upper Eel Humboldt Mattole Mendocino Coast Russian River Bodega APPROXIMATE TOTALS 961.000 122,000 137,000 229,000 ,171,000 810,000 77,000 101,000 2,700 107,000 473,000 43.800 (I 184,000 495,000 368.000 21,700 246,000 2,300 29,200 178.000 8.900 296,000 198,000 213,000 1 05.000 91.600 1 6.300 300 21.300 28,100 154,000 33,900 2,700 500 13.300 9,000 41,400 3,800 74,200 1 13,000 210,000 7,800 75,300 163,000 213.000 1,118,000 390,000 227,000 958,000 723,000 123,000 1,266,000 362,000 354,000 592,000 1,871,000 1,101,000 106,000 122,000 189,000 377.000 1, 923, 000 177.000 230,000 958,000 736,000 123,000 4,234,000 1,533,000 1,174.000 4,449.000 1 1 ,390,000 broken down for convenience in estimating water re- quirements into those portions inside and outside of national forests and monuments, and further segre- gated to areas above and below an elevation of 3,000 feet. The lands classified as "other water service areas" include recreational developments, both public and private, residential and industrial types of land use outside of urban communities, wild fowl refuges, etc. By far the greater portion of the lands are situ- ated in rough mountainous terrain, much of which is presently unaccessible. It is expected that even under conditions of ultimate development this portion will be only sparsely settled and will have only very minor requirements for water service. Summary Table 13 comprises a summary of probable ultimate water service areas, segregated into irrigated lands, urban and suburban areas, and other water service areas. 68 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA UNIT VALUES OF WATER USE Recent investigation of the water resources of the Klamath River Basin provided much of the data used in estimating unit values of water use in the North Coastal Area. These data were modified by standard methods to provide complete coverage of the area. TABLE 13 SUMMARY OF PROBABLE ULTIMATE WATER SERVICE AREAS, NORTH COASTAL AREA (In acres) Hydrographic unit Irrigable lands Urban and suburban areas Other water service areas Refer- ence number Name Approxi- mate total 1 2 3 4 5... Tule Lake Shasta Valley Scott Valley Upper Klamath Trinity __ 276,000 144,000 68,700 21.300 22,600 8,000 600 30,500 2,200 29,900 49,900 75,000 4,500 75,800 208,000 41,400 1,700 2,100 400 500 3,300 3,700 3,200 300 2,300 2,700 13,300 3,000 16,000 500 1,266,000 362,000 354,000 592,000 1,871,000 1,404,000 106,000 422,000 189,000 377,000 1,923,000 477,000 230,000 958,000 736,000 123,000 1,544,000 508,000 423,000 614,000 1,897,000 6 . 1,416,000 7 107,000 8 9 10 11 12 13 14 15 16 Del Norte. Redwood Creek Mad River Upper Eel Humboldt Mattole _ _ Mendocino Coast _ Russian River Bodega. 456,000 191,000 409,000 1,976,000 565,000 235,000 1,037,000 960,000 165,000 APPROXIMATE TOTALS 1,058,000 53,000 11,390,000 12,500,000 Irrigation Water Use In general, unit seasonal values of consumptive use of water on lands devoted to the various irrigated crops were computed by the methods outlined in Chapter II. Soil moisture studies conducted in Shasta, Scott, and Butte Valleys resulted in more accurate values of consumptive use in these areas. Pasture lands of the Klamath River drainage basin were segregated into meadow, improved pasture, and marginal pas- ture. Unit water use values presented in this chapter are for improved pasture, while 25 per cent higher use was assumed to occur on meadowlands and 25 per cent lower use was estimated for marginal pasture lands. Significant climatic variations, as related to con- sumptive use of water, occur among the hydrographic units of the North Coastal Area. For example, pre- vailing fogs and cool temperatures along the coast tend to reduce the consumptive use, and values for those areas affected were adjusted accordingly. Table 14 presents the estimated unit values of mean seasonal consumptive use of applied irrigation water and of precipitation on lands devoted to crops of the various groups. Unit mean seasonal consumptive use of applied water on farm lots was estimated to be about 0.5 foot in depth in the southerly portion and 1.0 foot in depth in the northerly part of the North Coastal Area. Estimates of unit mean seasonal consumptive use of precipitation on farm lots varied from 1.1 to 2.2 feet in the various hydrographic units, and averaged about 1.7 feet of depth. These estimates were employed for both present and probable ultimate conditions of development. Urban and Suburban Water Use Present unit seasonal values of use of water on urban and suburban water service areas of the North TABLE 14 ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS NORTH COASTAL AREA (In feet of depth) Hydrographic unit Alfalfa Pasture Orchard Vineyard Refer- ence number Name Applied water Precipi- tation Total Applied water* Precipi- tation Total Applied water Precipi- tation Total Applied water Precipi- tation Total 1 Tule Lake - 1.6 1.8 1.5 1.5 1.6 1.5 0.9 1.1 1.3 1.6 1.5 1.6 2.5 2.9 2.8 3.1 3.1 3.1 1.9 2. 2 1.9 1.9 2.0 1.9 1.4 0.9 1.3 1.5 2.4 1.6 1.4 1.3 2.1 2. 2 0.9 1.0 1.2 1.5 1.4 1.5 2.2 2.2 2.0 1.8 1.4 1.6 2.0 1.8 1.5 1.4 2.8 3.2 3.1 3.4 3.4 3.4 3.6 3.1 3.3 3.3 3.8 3.2 3.4 3.1 3.0 3.6 1.0 1.4 1.1 1.1 1.2 1.1 1.0 1. 1 1.4 1.7 1.7 1.7 2.0 2.5 2.5 2.8 2.9 2.8 2 Shasta Valley _ _ _ 3 Scott Valley _ _ _ 0.6 0.7 1.5 1.3 2.1 2.0 4 5 Trinity 6.. Klamath 7 Rogue.. _ 8 Del Norte .. _ 9 Redwood Creek _ 10 Mad River 1.3 2.0 1.3 2.0 1.8 1.9 3.3 3.8 3.2 0.7 1.3 0.7 1.8 1.6 1.7 2.5 2.9 2.4 11 Upper Eel _ 0.9 1.2 2.1 12 Humboldt 13 Mattole. _ _ 1 1 Mendocino Coast _ 1.1 1.9 1.9 2.0 1.7 1.7 3.1 3.0 3.6 15 1.2 1.2 1.5 1.5 2.7 2.7 0.8 1.4 ~ ; ~ 16 Bodega . * Within tin' Klamath River n-ai"age Basin Pasture was segregated Mo three classes. The value shown in this table applies to Improved Pasture, while a 25 per cent lower value was assumed for Marginal Pasture, and a 25 per cent higher value was estimated for Meadowland. NORTH COASTAL AREA 69 TABLE 14-Continued ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, NORTH COASTAL AREA (In feet of depth) Hydrographic unit Truck crops Miscellaneous fielc crops Hay and grai D Reference number Name Applied water Precipi- tation Total Applied water Precipi- tation Total Applied water Precipi- tation Total 1 Tule Lake -- 1.2 1.3 1.1 1.2 1.3 1.2 0.9 0.8 0.9 1.0 1.0 1.0 2.1 2.1 2.0 2.2 2.3 2.2 0.9 0.9 0.7 0.8 0.9 0.8 0.9 1.0 1.2 1.2 1.1 1.2 1.8 1.9 1.9 2.0 2.0 2.0 0.9 0.9 0.7 0.8 0.8 0.8 0.9 1.0 1.2 1.2 1.1 1.2 1.8 2 1.9 3 Scott Vallev 1.9 4 2.0 5 Trinity -- - - - -- 1.9 6 2.0 7 8 9 10 11 12 13 14 15 0.2 0.3 0.4 1.5 1.4 1.3 1.7 1.7 1.7 0.5 0.8 0.5 0.5 0.5 0.7 0.7 1.3 1.2 1.2 1.4 1.3 1.1 1.1 1.8 2.0 1.7 1.9 0.4 0.7 0.7 1.3 1.1 1.1 1.7 1.8 1.8 1.8 0.8 0.8 1.1 1.1 1.9 1.9 1.8 16 1.8 Coastal Area were estimated largely on the basis of population. Available records of delivery of water to the areas, as compiled by municipalities and other public water service agencies, provided data on the per capita use of water. Probable ultimate deliveries of water were estimated by applying the per capita water use to the estimates of ultimate urban popula- tion of the area. The water use thus determined was converted to unit use per acre. Estimates of present and probable ultimate unit seasonal values of water delivery to, and consumptive use of water on, urban and suburban water seiwice areas are found in Table 15. The gross delivery was assumed to be equivalent to the consumptive use, because of the limited oppor- tunity for re-use of the water in many of the coastal hydrographic units. Use of Wafer in Other Water Service Areas Unit values of water use on the miscellany of serv- ice areas grouped in this category were derived gen- erally from measured or estimated present deliveries of water to the typical development involved. In most cases the estimates were made in terms of per capita use of water, and the actual acreage of the service area was not a significant factor. In such cases the aggregate amount of water deliveries is relatively very small, and negligible recovery of return flow is in- volved. For purposes of study, therefore, the estimated unit values of delivery of water to these facilities were considered to be also the measures of consumptive use of applied water. Both the National Forest and Park Services pro- vided estimates of present and probable ultimate unit deliveries of water to all facilities within their juris- diction. The estimates were generally in terms of per TABLE 15 ESTIMATED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY IN URBAN AND SUBURBAN AREAS, NORTH COASTAL AREA (In feet of depth) Hydrographic unit Gross delivery of water* Refer- ence number Name Present Probable ultimate 1 1.0 1.7 1.9 1.8 1.6 2.0 0.7 0.7 1.0 1.0 1.0 1.1 1.0 1.0 1.0 1.0 1.5 2 2.1 3 Scott Vallev 2.2 4 2.0 5 Trinity 2.2 6 2.2 7 1.2 8 1.2 9 1.5 10 Mad River. . 1.5 11 1.5 12 1.5 13 Mattole 1.5 14 1.5 15 1.5 16 1.5 * Assumed equivalent to consumptive use of applied water. capita use of water and were based on actual measure- ments and experience. They varied widely from place to place and in type of use, and for this reason are not detailed herein. Unit values of consumptive use of water by the timber and timber-processing industries, aside from those industrial uses of water included in urban unit values, were derived largely from data obtained from the United States Forest Service. For sawmill opera- tions and plywood manufacture the estimated unit value of consumptive use of water was 1 acre-foot per 185,000 board-feet of lumber produced. Unit values of 70 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA consumptive use of water, as recommended by the Forest Service, were used for anticipated future manufacture of various other wood products, such as paper, pulp, and fiberboard. The use of water in the manufacture of wood pulp, the greatest water-con- suming- process, was estimated at 64,000 gallons of water per 1,000 board-feet processed. In the ultimate pattern of land use, marshlands and water surfaces of Upper Klamath Lake and Tule Lake will be important to the Pacific migratory water- fowl flyway. Following consultation with federal agen- cies, it was assumed that approximately 11,000 acres in Lower Klamath Lake would be maintained ulti- mately as marshland for waterfowl. Unit values of water use on both Lower Klamath Lake and Tule Lake Refuges Avere based on evaporation data. In other water service areas not encompassed by the foregoing specific types of water service, unit values of consumptive use of applied Avater under probable ultimate conditions of development were assigned on a per capita basis. In such areas, sparse residential, industrial, and recreational development is expected in t lie future. For areas outside national forests and monuments, it was estimated that the ultimate popu- lation density will average about eight persons per square mile, and that per capita consumptive use of water will be about 70 gallons per day. In areas inside national forests and monuments the same per capita use estimates were made, but the population density was assumed to average about four persons per square mile. The period of water use was assumed to be of three months' duration during the summer for areas above 3,000 feet in elevation, while water service for areas below 3,000 feet in elevation was assumed throughout the year. CONSUMPTIVE USE OF WATER In general, estimates of the amounts of water con- sumptively used in the North Coastal Area were de- rived by applying appropriate unit values of water use to the service areas involved. The estimates rep- resent the seasonal amount of consumptive use of water under mean conditions of water supply and climate. Table 16 presents estimates of present con- sumptive use of applied water and precipitation in areas having water service, and Table 17 presents cor- responding estimates for probable ultimate conditions of development. FACTORS OF WATER DEMAND In addition to the amount of water consumptively used in a given service area, certain factors relating to the water requirements, such as necessary rates, times, and places of delivery of water, quality of water, losses of water, etc., have to be given considera- tion in the design of water development works. In the North Coastal Area the most important of these de- mand factors are associated with the supply of water for irrigation. Of secondary importance are those re- lated to the supply of water for urban, suburban, recreational, and other uses. Those demand factors most pertinent to design of works to meet water re- quirements of the North Coastal Area are discussed in the following sections. Monthly Distribution of Water Demands Within the season, demand for irrigation water in the North Coastal Area varies from little or none dur- ing the winter rainy months to more than 25 per cent of the seasonal total during dry summer months. TABLE 16 ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF WATER ON PRESENT WATER SERVICE AREAS, NORTH COASTAL AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Unclassified areas Approximate Refer- Name total consumptive ence numbei Applied water Precipitation Applied water Applied water Applied water use of applied water 1 Tule Lake . . 133,000 75,100 51,600 (i,800 6,500 2,300 100 1,400 900 2,000 2.300 15,800 400 18,700 400 86,200 38,800 37,400 6,800 4,800 1,800 100 3,800 1,400 2,500 1,500 16,600 600 18,200 500 2,200 800 600 100 100 100 100 1,000 2,400 400 400 1 .600 800 900 100 800 900 4,700 1,100 5.600 200 200 200 200 200 300 400 1,000 900 100 800 200 136,000 2 Shasta Vallej .. __ . 78,500 3 Sr-ott Valley 52.800 1 7,300 8,200 6 3,300 7 100 8 Del Norti ... 2,600 '.' it ■' Navarro River 225 Gualala River. 35 5,000 320 Russian River. _ . .. 100 20,000 820 APPROXIMATE TOTALS. 13,800 2,860,000 15,140 13,800,000,000 kilowatt-hours, with an average annual water requirement of about 15, 000, 000 acre-feet, is theoretically possible. This power output is estimated on the assumption that the water supply is used pri- marily for power production, with no consideration given to use of water for other purposes. It is prob- able that the streams of the area ultimately will serve a combination of beneficial uses, and the water utilized for power development under combined operations will be considerably less than the theoretical poten- tial. Estimated theoretical power output, installed power capacity, and required inflow of water at the lowest plant are presented in Table 21 for streams of the North Coastal Area on which power development is feasible. Flood Control. Flood control, whether achieved by channelization or by storage, has as its objective the movement of flood flows to the ocean as rapidly as possible with the maximum protection against flooding of developed areas. Water dedicated to regu- lation for flood control purposes is largely unavail- able for other purposes and usually results in a net 74 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA loss to the available water supply. At present the only storage development for flood control in the North Coastal Area is Clear Lake Reservoir in Modoc County, which regulates the runoff of Lost River. The reservoir was originally designed for flood con- trol, with regulation achieved by storage and evapora- tion of floodwaters. Evaporation from the reservoir has amounted to about two-thirds of the total aver- age water supply to the reservoir, or about 60,000 acre-feet annually. Under present conditions of de- velopment all available water in the reservoir in ex- cess of evaporation and other losses is utilized by ir- rigable lauds iu the Klamath Project. The Coyote Project on the East Fork of the Rus- sian River near Ukiah has been authorized for con- struction by the United States Army Corps of Engi- neers as a flood control and Avater conservation proj- ect. This project would impound waters heading in the Russian River drainage basin, as well as diver- sions from the Eel River through the Potter Valley Power Plant. In addition to winter flood control, the Coyote Project would provide agricultural and urban water supplies to valley floor lands. Summer flow in the lower reaches of the Russian River, greatly en- hancing the recreational potential of the area, would also he provided by the project. Other existing flood control projects in the North Coastal Area are • < _ OOOOOOOOOO o T3 i 2 oocococcoc o CO +2 6 3 oq >o_ iq a *t o c «s -f co o u E O* iO* iO* CO* CO* 00" 00* -1* »H rH CD o O E 0J cj ■^ iO U o '•" co « I- OJ oooooooooo o U « w ooooooooo o Ih .3. 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' E 1 -2 >- , , "=,« 1 £ >2 C) 1 « j r g||sslslg Ph Ph < 1 !)() WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA gross urban and suburban area, tbe factors being based upon present urban land use patterns and ex- pected future changes. Table 35 presents the factors used in the estimate of ultimate urban development. In the determination of probable ultimate water service areas, the area occupied by farm lots was in- cluded as a portion of the gross irrigable area. In the determination of ultimate land use, certain assumptions were made as to the ultimate disposition of lands presently occupied by military reservations. All such areas presently existing were included within urban classifications. Water requirements within mili- tary reservations are generally less, on a gross acre- age basis, than in other urban classifications. The estimates of ultimate gross water requirements in these areas, therefore, should be generally conserva- tive, dependent upon the degree of change in land use due to establishment or abandonment of defense installations. Table 36 presents the probable ultimate pattern of land use in urban and suburban water service areas in hydrographic units of the San Francisco Bay Area. and Table 37 presents the probable ultimate gross urban and suburban areas in counties of the area. Other Water Service Areas The remaining 1,222,000 acres of the San Francisco Bay Area, not included in either the ultimate irrigated or urban and suburban water service areas, were not classified in detail regarding the nature of their prob- able ultimate water service. It was assumed that these "other water service areas" will include developed areas within the national and state parks, state beaches, and scattered recreational, residential, and industrial developments not included in the ultimate urban and suburban water service area. The greatest portion of these lands are in areas topographically or otherwise unsuitable for intensive development. Other water service areas within hydrographic units ami within counties are presented in Table 38. Summary Table 39 presents a summary of probable ultimate water service areas, segregated into irrigated, urban and suburban, and other water service areas. TABLE 38 OTHER WATER SERVICE AREAS UNDER PROBABLE ULTIMATE CONDITIONS, SAN FRANCISCO BAY AREA (In acres) Location Hydrographic unit Approximate gross area Reference number Name 1_._ 2 3 Marin-Sonoma.. ... Napa Valley ... 198,000 135,000 61,800 4 77,900 5 310,000 7 8 9 Alameda-Bayside. Santa Clara Valley San Mateo-Bayside 64,200 236.000 18.000 1 "0.000 10 600 APPROXIMATE TOTAL _. . 1,222,000 County 202,000 ta ...... 116,000 136,000 163.000 600 134,000 37 1 ,000 3,400 33,900 61,900 ROXIMATE TOTAL APF 1,222,000 TABLE 39 SUMMARY OF PROBABLE ULTIMATE WATER SERVICE AREAS, SAN FRANCISCO BAY AREA (In acres) Hydrographic unit Without reclamation of tidelands With reclamation of tidelands Irrigated lands L'rban and suburban areas Other nilli'l service areas Approxi- mate total Irrigated lands Urban and suburban areis Other water service areas Reference number Name Approxi- mate total l Marin-Sonoma 8,500 5,600 35,000 1 2,300 1,200 1,900 1,300 229,000 125,000 123,000 159,000 83,300 154,000 217,000 97,400 31,30(1 28,600 198,000 135,000 61,800 77,900 310,000 64,200 230,000 18,000 120,000 600 436,000 266,000 220,000 237,000 106,000 219.000 455,000 115,000 155,000 29,200 8,500 5,600 35,000 1 2.300 1 ,200 1,900 1,300 263,000 143,000 133,000 172.000 83.300 213,000 219,000 118,000 34,300 29,500 198,000 135,000 61,800 77,900 310.000 64.200 236,00(1 18,000 120,000 600 470,000 ■ Napa \ dley 284,000 ■■'. Solano 230.000 1 ( '•■ntia < !osta 250,000 S 6 7 8.. Livermore V allej Uameda Bayside Santa 1 lara \ alley . . Mat* o- Bayside 406,000 278,000 457,000 136.000 9 .,■! tal 155,000 in San 1 ranci i o 30,100 APPROXIM \TE TOTALS 65,800 1,250,000 1,222,000 2,538,000 65,800 1,408,000 1,222,000 2,096,000 SAX FRANCISCO BAY AREA <)1 UNIT VALUES OF WATER USE Unit seasonal values of water use in the San Fran- cisco Bay Area were determined in accordance Avith the methods and procedures described in Chapter II. Unit values of urban water use were based upon spe- cial studies conducted in various communities of the area by the East Bay Municipal Utility District and the San Francisco Water Department. Data employed in determination of unit values of water use for irri- gated crops included the results of studies conducted by various public agencies. Irrigation Water Use Unit seasonal A r alues of consumptive use of water by irrigated crops were, in general, determined in ac- cordance with the methods of Chapter II. Estimated unit seasonal values of consumptive use of applied irrigation water and of precipitation by various crop groups are presented in Table 40. The probable mean seasonal consumptive use of water on lands ultimately to be irrigated was estimated by applying the unit value of water use for truck crops, considered repre- sentative of average unit use for all irrigated crops, to the net irrigated acreage. Urban and Suburban Water Use The unit seasonal value of consumptive use of water in urban and suburban developments is influenced largely by geographic and geologic aspects of the de- veloped area. In a large part of the San Francisco Bay Area, present urban developments overlie either bedrock or impervious materials which prevent per- colation of water to any underlying bodies of ground water. Additionally, the sewage outflow is discharged to San Francisco Bay from much of the urban area overlying free ground water. In these areas, the con- sumptive use of applied water was considered to be equivalent to the unit net delivery of water, as only minor ground water recharge from the applied water occurs. In the determination of present water requirements in the free ground water zones of Liverrnore and Santa Clara Valleys, ground water recharge from the present urban area was estimated as a separate quan- tity. The entire urban and suburban development in the San Francisco Bay Area was assumed to be sew- ered under conditions of probable ultimate develop- ment, and no recharge to underlying ground water from this source was considered to occur. Present unit values of consumptive use of applied water were determined for most types of urban land use from studies of data collected in extensive field sampling of actual water deliveries to consumers in each land use classification. The sampling procedures employed are discussed in Chapter II. The estimated values where records of deliveries were not available \ve re based upon estimates of consumptive use on similar areas in other parts of California. Ultimate unit values of consumptive use of applied water were obtained by modifying present values in certain classifications to account for indicated trends. In this connection, a study of historical trends was made in the City of San Francisco on a basis of use of water per acre, and in the distribution areas of several other large water service agencies on a basis of per capita use. However, the results of this study were unsatisfactory, as it was not possible to derive a maxi- mum limitation on the ultimate unit value of use of applied water. In view of the foregoing, assumptions were made concerning future increases in values of water use on various urban types, and with regard to eventual land use practices in different hydrographic units. It was estimated that increasing use of modern water-using appliances, such as automatic washers and garbage TABLE 40 ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, SAN FRANCISCO BAY AREA (In feet of depth) Hydrographic unit Alfalfa Pasture Beans Flowers Grain Orchard, almond-prunes Refer- ence num- ber Name Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- eipita- tion Total 1 Marin-Sonoma Napa Vallev - 2.0 1.6 3.6 2.1 2.1 2.4 2.3 2.3 2.1 2.2 2.1 1.9 1.3 1.3 1.2 1.2 1.2 1.2 1.2 1.3 1.2 3.4 3.4 3.6 3.5 3.5 3.3 3.4 3.4 3.1 1.0 1.0 1.0 1.1 0.9 1.0 1.0 1 .1 0.8 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1 .1 1.2 2.2 2.2 2.2 2.3 2.1 2.2 2.2 2.2 2.0 1.1 1.1 1.3 1.3 1.3 1.2 1.2 1.4 1.4 1.3 1.3 1.3 1.3 1.3 2.5 2 ■> .-, 3 2 6 4____ ( !ontra Costa 0.8 1.1 0.7 1.1 1.1 1.2 1.9 2.2 1.9 2.6 2.6 2 . 5 2.5 5 6 7 Liverrnore Valley Alaineda-Bayside Santa Clara Valley _ _ San Mateo-Bayside__ San Mateo-Coastal_ _ San Francisco 2.4 2.1 2.1 2.2 1.9 1.3 1.5 1.5 1 .5 1.5 3.7 3.6 3.6 3.7 3.4 0.4 0.6 0.7 1.2 1.2 1.1 1.6 1.8 1.8 8 0.7 0.5 1.2 1.2 1.9 1 .7 9 0.5 1.2 1.7 10 92 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 40— Continued ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, SAN FRANCISCO BAY AREA (In feet of depth) Hydrographic unit Orchard, walnut Orcharc other decid JOUS Sugar beets Truck Vineyard Refer- ence number Name Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- eipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total 1 Marin-Sonoma . 1.6 1.7 1.8 1.9 1.9 1.7 1.2 1.7 1.4 1.4 1.2 1.2 1.2 1.3 1.3 1.4 3.0 3.1 3.0 3.1 3.1 3.0 2.5 3.1 1.4 1.4 2.8 1.1 1.1 1.2 1.2 1.1 1.1 1.2 1.0 1.1 1.2 1.2 1.2 1.2 1.1 1.2 1.1 2.0 1.7 2.3 2.3 2.4 2.4 2.2 2.3 2.3 3.0 2.8 0.9 1.2 2.1 2 3 Solano _ _ __ 1.7 1.7 1.7 1.5 1.2 1.6 1.3 1.3 1.2 1.2 1.3 1.3 1.3 1.3 3.6 2.9 2.9 2.8 2.5 2.9 2.6 1.1 1.0 1.0 0.9 0.9 1.1 0.9 1.1 1.2 1.2 2.2 4 1.9 5 6 Livermore Valley 1.2 1.1 1.2 1.2 1.2 1.1 2.4 2.3 2.3 2.1 2.1 7 2.1 8__ 9 10 disposal units, would result in an ultimate residential use per acre of some 15 per cent greater than at present. Unit values of present multiple residential use of water were found to differ in the various hydro- graphic units, being exceptionally high in the San Francisco Hydrographic Unit. With the exception of this hydrographic unit, therefore, it was assumed that the ultimate multiple residential use would be the same in all hydrographic units, and 15 per cent greater than the highest present use. It was further assumed that in the San Francisco Hydrographic Unit ultimate multiple residential unit use of water would be 15 per cent greater than the present rela- tively high value. In hydrographic units which at present have a rela- tively minor degree of industrial development, ulti- mate unit values of water use for the industrial classification were generally assumed to be the same as the present value in the more intensively developed areas. In those hydrographic units presently some- what more highly developed, adjustments were made in the unit values of use of applied water where it was believed that the distribution of industry would change in the future. In the remaining classes of land use, including commercial, airfields, irrigated parks, and institutions, the ultimate unit values of use of applied water were assumed to be equal to the present values. The present and probable ultimate values of net delivery of applied water in urban and suburban areas are presented in Table 41. Weighted mean unit values applicable to net urban and suburban water service areas within hydrographic units are also pre- sented in Table 41. This table indicates that the prob- TABLE 41 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL UNIT VALUES OF WATER DELIVERY IN URBAN AND SUBURBAN AREAS, SAN FRANCISCO BAY AREA (In feet of depth) Hydrographic unit Residential Industrial Commercial Instit utions Irrigated Weighted Reference number Name Single Multiple General Airfield parks mean* Pres- ent Ulti- mate Pres- ent Ulti- mate Pres- ent Ulti- mate Pres- ent Ulti- mate Pres- ent Ulti- mate Pres- ent Ulti- mate Pres- ent Ulti- mate Pres- ent Ulti- mate 1 . 2 Marin-Sonoma Napa Valley. 2 2 2 2 2 2 2 2 2 4 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.3 4.6 7 4 4 (i 4 7 6 7 7 15 8.1 8.1 8.1 8.1 8.1 8.1 8.1 8.1 8.1 17.3 6 4 4 19 45 9 8 8 2 6 7 8 8 14 8 9 9 8 2 6 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 4 4 4 4 4 4 4 4 4 10 4 4 4 4 4 4 4 4 4 10 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 2.3 2.1 2.0 5.5 3.6 2.0 1.8 1.6 1.7 5.1 3.0 2.8 3 1 5 6 7 Solano ' 'ontra ' V-ta .... Livermore Valley Al.imrda-Bayside Santa ( lara Valley 3.1 3.7 3.1 2.7 3.0 s 9 San Mateo-Bayside San Mateo ' loastal 2.8 2.4 10... rancisco « n .ii l l D MEAN 5.7 2.2 2.3 9.8 8.5 11.1 8.7 0.4 0.4 5.2 4.2 2.0 2.0 1.0 1.0 2.7 3.1 NOTE: Water delivery assumed equivalent to . 3 36.6* 31.3* 8.5 7. 5 2 . 5 2.8 2.6 3.1 5. 1 5.9 100.0 100.0 ui Include low watei using Indu trial areas. Losses in Urban Water Utility Systems Analysis of available records of urban water pro- duction and metered delivery resulted in determina- tions of transmission and distribution losses, expressed as per cent of production, of from 5.5 per cent to 21 per cent. However, a majority of the system losses, including those of all major water systems, fell within a range of 8 to 12 per cent of production. Based on these findings, a value of 10 per cent of net delivery of water was estimated as representing a reasonable allowance for both present and ultimate system losses of water. It is believed that there will not be a signif- icant difference in present and ultimate system losses. Distribution of Urban Water Demands An analysis of records covering 77 per cent of the total estimated 1949 delivery of water to urban areas resulted in the determination of monthly demands as presented in Table 45. These values were determined principally from weighted mean percentages of monthly deliveries of water in urban areas of the San Francisco Water Department, East Bay Munici- pal Utility District, Contra Costa County Water Dis- trict, San Jose Water Works, Marin Municipal AVater District, and Vallejo Municipal Water Works. Deliv- eries of water in Napa, Suisun, Fairfield, Mountain View, Sunnyvale, Benicia, Petaluma, and Sonoma were also included, as were the monthly requirements of the Sonoma State Home, Veterans Home of ( "ali- fornia, and Travis Air Force Base. The mean seasonal distribution of monthly irriga- tion water demand, based upon records of agricul- tural power sales over a period of five years in the SAN FRANCISCO BAY AREA 95 North Bay, East Bay, and San .lose Divisions of the Pacific Gas and Electric Company, is also presented in Table 45. TABLE 45 AVERAGE DISTRIBUTION OF MONTHLY WATER DEMANDS, SAN FRANCISCO BAY AREA (In per cent of seasonal total) Month Irriga- tion demand January February March April May June . July August . . September October . November December TOTALS 100.0 Irrigation Water Service Area Efficiency "Water requirements in the San Francisco Bay Area, were determined from consideration of total water application in each bydrographic unit, con- sumptive use of applied water, subsequent re-use of a portion of the applied water, losses associated with conveyance of water to places of use, and the final loss by discharge to the ocean. The effect of irrecov- erable losses upon the water requirements may be measured by the water service area efficiency, defined as the ratio of consumptive use of applied water in a service area to the gross amount of water deliv- ered to the area. Irrigation water service area effi- ciencies were estimated for each bydrographic unit of the San Francisco Bay Area. Irrigation efficiency is defined as the ratio of con- sumptive use of applied water to the total amount of water applied to irrigated crops. In the San Fran- cisco Bay Area there are significant variations in irrigation efficiency, dependent upon crop, soil type, topographic characteristics, cost and availability of water, and local irrigation practice. Generally throughout the area, present irrigation efficiencies average about 50 per cent. This factor was applied without adjustment in the areas overlying ground water pressure zones, where the excess application does not return to storage in the subsurface aquifers. In free ground water zones, the re-use of water made possible by its return to ground water through perco- lation results in the attainment of relatively higher efficiencies. The ground water recharge in each hydro- graphic unit was estimated by determining the effec- tive absorptive area occupied by agricultural devel- opment and computing the probable recharge there- from. The total net irrigation requirement in free ground water zones was estimated by subtracting this value for ground water recharge from the amount of the gross application of water necessary in accord- ance with the indicated 50 per cent efficiency factor. Abundant supplies of surface water are not avail- able for most irrigated localities in the San Francisco Bay Area. Virtually all water supplies utilized for irrigation are pumped from ground water basins, in several of which the indications of overdraft are evi- dent. It is anticipated that increased demands on the limited local supplies will operate in the future to enforce greater economy in the application of water for irrigation. This factor, together with probable in- creased costs for development of supplemental water supplies, should result in a material increase in future irrigation efficiency. The ultimate irrigation water requirements in pressure zones were estimated by assuming an eventual irrigation efficiency of 70 per cent. Probable ground water recharge in free ground water zones was estimated in the same manner as for present conditions, assuming, however, an irri- gation efficiency of 70 per cent. Table 46 presents estimated irrigation water service area efficiencies under present and probable ultimate conditions of development. It should be noted that water service area efficiencies ultimately attained will be dependent in great part on plans for ultimate water service, and on the extent to which return flow from irrigated lands and urban areas can be regu- lated and re-used. For this reason the. predictions may be subject to appreciable changes as planning continues. TABLE 46 ESTIMATED WEIGHTED MEAN IRRIGA- TION WATER SERVICE AREA EFFI- CIENCY WITHIN HYDROGRAPHIC UNITS, SAN FRANCISCO BAY AREA (In per cent) Hydrographic unit Present Refer- ence num- ber Name Prob- able ulti- mate 1 2 Marin-Sonoma (10 GO 55 50 85 50 85 50 50 70 70 3 4 5 5 7 8 9 10 Solano Contra Costa Livermore Valley. Alameda-Bayside. Santa Clara Vallev San Mateo-Bavside San Mateo-Coastal. 70 90 70 85 70 WEIGHTED MEAN 05 75 96 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA WATER REQUIREMENTS Water requirements, as the term is used in this bulletin, refer to the amounts of water needed to provide for all beneficial uses of water and for any irrecoverable losses incidental to such uses. Certain requirements for water which are basically noncon- sumptive in nature are discussed briefly in the fol- lowing section in general terms. Following this, water requirements of a consumptive nature are evaluated for both present and probable ultimate conditions of development. Requirements of a Nonconsumptive Nature The principal nonconsumptive water requirements of the San Francisco Bay Area are those pertaining to flood control, preservation and propagation of fish and wildlife, repulsion of sea water from groiuid water basins, and salt balance in irrigated areas. Navigation is restricted to various arms of the bay and to tidal channels of some of the tributary streams. In general, the fresh-water outflow provided from the Central Valley Area for salinity control, naviga- tion, maintenance and propagation of fish life, and for other purposes, will provide for all necessary fresh-water nonconsumptive uses in the San Fran- cisco Bay Area. It is anticipated that future devel- opments will not result in any fresh-water require- ment for these purposes. This bulletin does not evaluate the quantities of water involved in satisfying these nonconsumptive requirements, since these quantities in many instances are dependent upon the evolution of definite plans for the development of water resources. Their consid- eration herein is limited to discussion of their impli- cations as related to planning for future water resource development. Flood Control. The San Francisco Bay Area is characterized by flood problems which are principally of a local nature. Most of the presently existing de- velopment has taken place on land of sufficient slope to prevent accunudation of flood waters or in areas not under the influence of large flood-producing streams. There are, however, some areas where serious inundations have taken place. Marshlands at the mouths of most of the streams entering the bay are covered by high water in almost all years. High tides in these regions also contribute to the hazard of flood damages. Flood problems are somewhat less severe inland from the bay and ocean. Reservoirs on several streams, notably Coyote Creek and the tributaries of tin' Guadalupe River, provide incidental flood protec- tion as a result of the impounding of water supplies for conservation. Levee systems have been built on the lower reaches of mosl d' the Larger streams of the San Francisco Bay Aica, tint they have not been as effective in reducing flood damage as had been expected, principally due to the recent intensive urban development in the affected areas. Several flood control and water conservation dis- tricts have been organized in the area, and the forma- tion of others is under consideration. Such districts complement the work of the Corps of Engineers in the planning, construction, and operation of flood control works throughout the San Francisco Bay Area. Most additional works presently contemplated consist of channel improvements, storm drains, and detention reservoirs of small capacity in the tributary drainage basins. Additional urbanization in the San Francisco Bay Area will create drainage and storm-water problems that will require consideration in future planing, and the construction of flood-protection works. Fish and Wildlife. The San Francisco Bay Area is limited with regard to fresh-water sport fishing, but the marine and brackish waters of the area sup- port both sport and commercial fisheries of consider- able importance. The principal commercial fishes are king salmon, shad, and Pacific herring. Salmon and shad migrate through San Francisco Bay into the Central Valley for spawning purposes, while Pacific herring spawn in San Francisco Bay. A commercial fishery of some importance for shrimp also exists in the bay. The com- bined landings of these species amount to an annual quantity of several million pounds. The principal sport fish of the area is the striped bass, which is taken mainly in the bays and brackish waters of the numerous sloughs and channels. Large runs of steelhead rainbow trout use the bays and delta as a passageway from the ocean to the streams of the interior valley, although very little angling for them takes place in the marine and brackish waters. Steelhead trout also migrate into several of the local streams tributary to San Francisco and San Pablo Bays, such as San Francisquito, Stevens, Coyote, and Alameda Creeks, and the Napa River. Steelhead trout move annually from the ocean into several of the coastal streams of San Mateo County, including Pes- cadero and San Gregorio Creeks. The leading stream fishery of the area is that for the adult steelhead trout. Trout form resident populations in some of the streams, and along with the young steelhead contrib- ute to the fishery. Silver salmon migrate from the ocean into suitable streams in the area, principally Pescadero and San Gregorio Creeks, and provide some sport fishing. Several lakes in the San Francisco Bay Area are stocked witli trout, including Phoenix Lake, Laguni- tas, Alpine, Bon Tempe, Stevens Creek, and Lexington Reservoirs, and Merced, Madigan, and Frey Lakes. Warm-water game fishes, including the black basses, sunfishes, crappies, and catfishes, are present in a number of farm ponds and small reservoirs. Large- SAN FRANCISCO BAY AREA 97 mouth black bass are present in parts of the Napa River. Reservoirs stocked with warm-water game fishes include Anderson, Calero, and Coyote. For large numbers of anadromous fishes, the salt and brackish waters of the bay serve as an entryway to spawning grounds. Sport and commercial fishing in the San Francisco Bay Area are sustained primarily by these migrations. Fresh-water demands of anad- romous fisheries are a consideration in the Central Valley Area, and do not constitute an additional de- mand on the local water supplies of the San Francisco Bay Area. It is considered doubtful that the limited water re- sources of the San Francisco Bay Area can meet additional water requirements for the preservation and enhancement of fish life, except when such re- quirements do not decrease supplies available to meet consumptive requirements. This does not, however, signify that fisheries will not benefit by future water development, particularly by importation of water from outside sources. Reservoirs created to impound water will provide additional habitat for game fish populations. Water released in stream beds for down- stream requirements will, if the water is drawn from the deeper parts of the reservoir, provide conditions suitable for the development of trout fisheries. It is necessary only to provide minimum pool elevations in the reservoirs, and assure public access to the created waters, to realize fisheries benefits from water develop- ment in the San Francisco Bay Area. At present, virtually all water demands of migra- tory waterfowl that frequent the marshy areas of the bays are supplied from salt and brackish waters. It is anticipated that the same condition will prevail under ultimate conditions, and that the fresh-water demand will be insignificant. Repulsion of Salt-Water Intrusion From Ground Water Basins. In portions of the San Francisco Bay Area directly bordering the southern shores of the bay, intrusion of saline water into shallow aquifers has become a serious problem. In the area of southern Alameda County centered about Niles, Irvington, and Centeiwille, salt-water intrusion is a present critical source of damage. There is danger of degradation of water supplies in deeper confined aquifers by con- tamination from overlying shallow strata. This may occur through natural or man-made fissures in the confining blanket, abandoned or defective wells, or by possible intrusion of salt water from the bay if pres- ent pumping rates, whereby depression of the hy- draulic gradient occurs to the extent that a landward slope results, should continue to prevail in the fu- ture. In view of the extensive use being made of this source of ground water supply at the present time, the prospect of such degradation is very serious. Ex- cept in a few local areas, however, such as at the edge of the confining blanket in the Niles Cone region, the 4—99801 quality of water in the lower aquifer has so far re- mained satisfactory. Intrusion of salt water may be prevented by main- taining pressure levels in these basins at elevations above sea level. Determination of the quantities of water required to prevent sea-water intrusion will be dependent upon specific plans of development and pumping draft. However, it appears that a substan- tial amount of water will be unavoidably lost by out- flow under such conditions, particularly from areas in Santa Clara and Alameda Counties adjacent to the bay. Studies conducted by the Division of Water Re- sources in Alameda County indicate that if pumpage from the presently overdrawn ground water basins underlying the Niles Cone area were limited to the safe yield of the basins, intrusion of salt water from the bay would be eliminated. Other areas of possible saline intrusion which have been studied by the United States Geological Survey in cooperation with the Division of Water Resources are the Clayton and Ygnacio Basins in northern Con- tra Costa County, the Fairfield region in Solano County, and the Napa-Sonoma and Petaluma Basins bordering San Pablo Bay. In part of the Fairfield region, pressure levels approximately 20 feet below sea level are indicative of possible imminent intrusion of water from the bay. In the Napa-Sonoma Basin, there is evidence that natural and man-made breaks in the confining clay layers, and abandoned or de- fective wells, have produced local pollution from overlying brackish and saline sloughs. Salt Balance. Local irrigation water supplies in the San Francisco Bay Area are, for the most part, obtained by pumping from ground water storage. The estimates of requirements for water which are subse- quently set forth are predicated upon utilization of ground water storage capacity so as to facilitate the re-use of local and imported water applied to lands in excess of requirements for consumptive use. Na- tural replenishment of many ground Avater basins in the San Francisco Bay Area is derived from surface drainage from tributary watersheds, and to a limited extent from subsurface outflow from upstream basins. The mineral quality of the ground water contained in these basins must be protected from deterioration in order to maintain the utility of the storage capacity. This will require sufficient drainage from each basin to remove a quantity of dissolved salts equivalent to the amount of salt input to the basin. Quantitative estimates of the amount of water required for this purpose will necessarily depend upon the formulation of specific plans for future development in each in- stance. Requirements of a Consumptive Nature Requirements for water represent the quantities of water, other than precipitation, which must be sup- plied to provide for beneficial consumptive use of lis WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA water on irrigated lands, urban and suburban areas, and other water service areas, and to provide for irrecoverable losses incidental to such use. Present and probable ultimate water requirements in the San Francisco Bay Area were determined by use of the previously derived estimates of total water applica- tion and consumptive use of applied water, giving consideration to the possible re-use of a portion of the applied water and to losses incurred in convey- ance to the place of use. In general it was assumed that, in irrigated water service areas overlying or immediately adjacent to major free ground water basins, re-use of all water applied in excess of consumptive use could be accom- plished. The irrigation water requirement for such areas was therefore taken as equal to the consumptive use of applied water. In water service areas adjacent to the bay or overlying confined aquifers, it was as- sumed that no re-use of applied water could be effected in excess of consumptive use. The irrigation water requirement in such cases was assumed to be equal to the total water applied plus irrecoverable conveyance losses. Urban and suburban water requirements were evaluated in the same general manner as those for irrigated lands, except that consideration was given to the effect of sewerage facilities with ocean dis- charge on requirements in those urban areas overly- ing free ground water basins. The present water re- quirement for these urban areas was estimated as the sum of the consumptive use of applied water, present export to the ocean of sewage, and irrecoverable con- veyance loss. The probable ultimate urban require- ment was assumed to be the computed requirement for applied water plus an additional 10 per cent for irrecoverable conveyance losses. Since the entire ur- ban development in the San Francisco Bay Area was assumed to be sewered under ultimate conditions of development, it was considered improbable that size- able contributions to ground water would occur from this source. Ultimate water requirements in other water service areas were estimated on the basis of expected utiliza- tion of such areas for recreational and other purposes. The water to meet this requirement is expected to be developed from local supplies, and to be utilized prin- cipally for domestic purposes. No consideration was given to reclamation and re- use of sewage which would otherwise be discharged to the ocean. Large quantities of water in the San Francisco Lay Area could be salvaged in this manner, and experimental projects to determine the feasibility of reclamation of sewage are presently being con- ducts! in southern California. Sufficient data are not presently available to evaluate the effect of such sew- age reclamation on requirements for supplemental water- supplies. Exploilalion of this potential source of water supply is considered as development of new water for purposes of this bulletin. In several hydrographic units of the San Francisco Bay Area the present application of water on ir- rigated lands is somewhat less than the optimum amount required for consumptive use for agriculture. This condition is caused by the low transmissibility characteristics of presently developed ground water resources, and the consequent inability to produce the required amounts of water from existing wells. It is believed that crop production in these areas has been adversely affected thereby. Table 47 presents estimated present and probable ultimate water requirements for each hydrographic unit of the San Francisco Bay Area. Estimates of ultimate water requirements, ex- pressed as a function of the relative proportions of the habitable area which may be devoted to urban and suburban and agricultural development, are pre- sented in Table 48. In deriving the quantities ex- pressed in this table, the present irrigated crop pat- tern was gradually modified so that truck crops, flowers, and dairies constituted increasing percentages of the lands available for irrigated culture. Table 48 demonstrates that a relatively small effect on the ultimate water requirement results from a comparatively large variation in the degree of urbani- zation. The change in seasonal water requirement for and increase in urbanization from 50 to 100 per cent amounts to only about 10 per cent of the average re- quirement for the area. The assumption of practically complete urbanization under conditions of ultimate development provides a conservative basis for future planning of projects to provide for necessary supple- mental water requirements. Ultimate urban and suburban water requirements in the San Francisco Bay Area were also independ- ently estimated on the basis of forecast ultimate popu- lation. This procedure involved determination of the areas ultimately susceptible of urban and suburban development, the ultimate population densities in these areas, and the ultimate per capita water require- ment. The general method of estimating ultimate popula- tion was outlined in Chapter II, "Methods and Pro- cedures." In most of the San Francisco Bay Area it was assumed that future residential development would take place in accordance with patterns indi- cated by recent building trends, so that over-all densi- ties would be somewhat less than the existing densities in the present fully developed areas. An exception to such a pattern Avas forecast for the northern portion of Contra Costa County, where the expected concen- tration of very heavy industry was assumed to require the future development of housing with the present heavier density characteristics. SAN FRANCISCO BAY AREA 99 LU ■< o u. co t- Z LU LU CK o LU OS < z o co < co^ Z< hs < " !£0 CO lu LO 1 < LIE Z5 s3 Cfl CO < O ex. 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OOOOOOOO'C'O o 3 S-O-e a o_ o_ o_ o_ o_ o_ o_ o_ o_ o_ o O -eggs o* oo" »-o oo* o* oo* r-* o" ■* lo n n ai io o n h h 'o n CM .t2 O CI CM rt* CM CO lO CN ^H o £ CO co" -2 c oooooooooo o cd 3 CO o o o o o o o o a ■>* CM TfH TP ^H CI ~H cc (V H C8 O rH Cl" •g fa- o- 01 u T3 oooooooooo o a * •** o o o o o o o o £ CD C0_ CO_ CO t^ -* t^ CO cm" od t>" tjT ^h" cm" r-T oo" ^H »C ^H o> P 1— t .i "3 oooooooooo o * "S oooooooooo o d 5 &l t-H ^ O i-H 0_ 0_ rH Cl_ ^ 5 a 33 CD id O* CD* 00* Cl" o" CD* »d O id ciMfiHrtoonHO) CN t- g < a i n oooooooooo o d CD "S5 rt oooooooooo o C| CM_ CO_ t^ CO_ »^ CN O Cl^ O CD_ a 0> — - ^i* id co" cm" ci" id »d ~h" id id CO "3 f _J ! < g o u M O "? > !° 2 -So a a 1 .9 a § I E 1 J S S fe << Z tc O i-1<1 to tyi oj tB Ph rH •5 w < £ § a s 1.1 1.5 1.4 1.1 0.9 1.0 1.0 0.9 0.9 1.0 1.0 1.1 0.8 1.0 0.9 1.0 1.0 1.8 2.1 1.6 2.1 1.8 2.1 1.8 1.9 2.5 2.8 2.5 2.0 2.5 2.4 0.4 0.4 1.2 1.2 1.6 2 1.3 0.9 1.0 1.1 2.3 2.0 1.6 3__ __ 4___ . 0.4 0.4 0.4 1.2 0.9 0.9 1.6 5 Lower Salinas 1.1 1.3 0.9 0.9 2.0 2.2 1.3 1.3 6 7 0.4 0.7 0.6 0.7 0.5 0.7 0.8 1.0 1.1 0.8 1.0 0.9 1.0 1.0 1.4 8 San Luis Obispo _ 1.8 9 1.4 10 Santa Maria 1.0 1.0 2.0 1.7 Interior 1.4 11 1.1 1.0 2.1 1.7 12 1.8 area was not a significant factor. In such cases the aggregate amount of water deliveries is relatively very small, and negligible recovery of return flow is in- volved. For purposes of study, therefore, the esti- mated unit values of delivery of water to these facil- itirs were considered to be also the measures of con- sumptive use of applied water. Both the National Forest and Park Services pro- vided estimates of present and probable ultimate unit deliveries of water to all facilities within their juris- diction. The estimates were generally in terms of per capita use <>r water, and were based on actual meas- urcnients ami experience. They varied widely from place to place and in type of use, and for this reason are not detailed herein. Records of delivery of water to private recreational areas in the Santa Cruz Mountains were available from local water service agencies. On an areal basis, unit values of water delivery are extremely low, averaging only about 0.05 foot of depth per season. Recovery of return flow is negligible, and unit de- liveries of water were considered to be also the measures of consumptive use of applied water. The value of unit use of water by military estab- lishments was derived on a per capita basis, from available records of delivery of water and estimates CENTRAL COASTAL AREA 115 TABLE 66 ESTIMATED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY IN URBAN AND SUBURBAN AREAS, CENTRAL COASTAL AREA (In feet of depth) Hydrographic unit Gross delivery of water* Reference number Name Present Probable ultimate 1 2 3 Santa Cruz . _ _ San Benito.. . 0.9 1.2 1.4 1.5 1.7 0.5 1.2 1.3 1.7 1.0 0.7 2.2 1.7 4 5 Upper Salinas 2.0 2.2 6 7__ Carmel __ _ 2.0 1.7 8 9__ San Luis Obispo _ 1.5 1.5 10 11 Santa Maria 1.5 1.5 12 1.5 * Assumed equivalent to consumptive use of applied water. of population of the camps involved. On these bases it was estimated that present consumptive use of ap- plied water by such establishments averages about 75 gallons per capita per day. It was assumed that this value would hold in the future. For other Avater service areas not encompassed by the foregoing specific types of water service, unit values of consumptive use of applied water under probable ultimate conditions of development were assigned on a per capita basis. In such areas, sparse residential, industrial, and recreational development is expected in the future. For areas outside national forests, monuments, and military reservations, it was estimated that the ultimate population density will average about eight persons per square mile, and that the per capita consumptive use of water will be about 70 gallons per day. In areas inside national forests, monuments, and military reservations the same per capita use estimates were made, but the population density was assumed to average about four persons per square mile. The period of water use was assumed to be of only three months' duration during the summer for areas above 3,000 feet in elevation, while water service for areas below 3,000 feet in elevation was assumed to be throughout the year. CONSUMPTIVE USE OF WATER In general, estimates of the amounts of water con- sumptively used in the Central Coastal Area were de- rived by applying appropriate unit values of water use to the service areas involved. The estimates repre- sent the seasonal amount of consumptive use of water under mean conditions of water supply and climate. Table 67 presents estimates of present consumptive use of applied water and precipitation in areas hav- ing water service, and Table 68 presents correspond- ing estimates for probable ultimate conditions of de- velopment. FACTORS OF WATER DEMAND In addition to the amount of water consumptively used in a given service area, certain factors relating to the water requirements, such as necessary rates, times, and places of delivery of water, quality of water, losses of water, etc., have to be given, con- sideration in the design of water development works. In the Central Coastal Area the most important of these demand factors are associated with the supply of water for irrigation. Of secondary importance are those related to the supply of water for urban, sub- urban, recreational, and other uses. The demand factors most pertinent to design of works to meet water requirements of the Central Coastal Area are discussed in the following sections. TABLE 67 ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF WATER ON PRESENT WATER SERVICE AREAS, CENTRAL COASTAL AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Unclassified areas Approximate Refer- Name total consumptive ence number Applied water Precipitation Applied water Applied water Applied water use of applied water 1 2,700 82,000 11,900 7,400 171,000 1,100 negligible 7,200 82,100 37.800 22,400 5,800 81,300 19,500 4,300 128,000 1,400 negligible 5,600 47,100 23,400 20,500 100 700 200 1,000 100 500 200 300 7,300 2,500 2,700 2,600 9,300 8,100 negligible 4,800 2,100 1,400 6,600 300 1,500 7,200 100 200 500 2,600 2,200 10,400 85,200 1 I.SIKI 11,500 189,000 9,200 100 12,300 85,200 42,000 31,500 2.. 3 4 5 6 8 9 10 11 12 APPROXIMATE TOTALS. .. 426,000 337,000 3,100 47,400 14,600 491,000 116 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 68 PROBABLE MEAN SEASONAL CONSUMPTIVE USE OF WATER ON ULTIMATE WATER SERVICE AREAS, CENTRAL COASTAL AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Approximate total consumptive use of applied water Refer- Name ence number Applied water Precipitation Applied water Applied water Applied water 1 Santa Cruz - _ _ . _ __ . __ _ 7,100 163,000 19,700 352,000 270,000 7,800 15,400 88,900 121,000 209,000 130.000 48,000 10,500 166,000 29,700 325,000 220,000 8,100 14,100 71,700 59,500 154,000 108,000 47,100 100 1,400 300 2,100 2,000 100 100 500 600 1,300 800 500 32,600 1 1 ,700 8,300 9,800 40,700 32,200 300 14,700 1,200 9,000 5,300 32,600 3,600 600 2,100 7,300 200 500 400 200 1,500 2,400 4,400 43,400 2 176,000 3 Pajaro ___ 28,300 4 366,000 5 320,000 6 40,300 7 Monterey Coast. . . _ _____ 16,300 8 104,000 9 123,000 10 Santa Maria _ 221,000 11 Santa Ynez 139,000 12 85,500 APPROXIMATE TOTALS 1,432,000 1,214,000 9,800 198,000 23,200 1,663,000 Monthly Distribution of Water Demands "Within the season, demand for irrigation water in the Central Coastal Area varies from little or none during the winter rainy months to more than 20 per cent of the seasonal total during dry summer months. Available information indicates that considerable variation in water demand also occurs with crop and soil types, and with distance from the coast. Urban water demands, while substantially higher in summer than in winter months, are far more uniform through- out the season than are those for irrigation. They vary from five to six per cent of the seasonal total during the months of December through March, to over ten per cent from June through September. Rep- resentative data on monthly distribution of irriga- tion and urban water demands in the Central Coastal Area are presented in Table 69. Irrigation Water Service Area Efficiency In study of irrigation water requirements of the Central Coastal Area it was found to be desirable to estimate the over-all efficiency of irrigation practice in the various service areas. Irrigation water service area efficiency was measured by the ratio of consump- tive use of applied irrigation water to the gross amount of irrigation water delivered to a service area. Present irrigation water service area efficiencies were estimated after consideration of geologic condi- tions of the service areas involved, their topographic position in relation to sources of water supply and to other service areas, consumptive use of water, irriga- tion efficiency, usable return flow, and urban and suburban sewage outflow. Irrigation efficiencies, or the ratios of consumptive use of applied water to the total water applied, were determined from studies conducted by the Division of Water Resources for the Salinas Valley and the Pajaro area. Available information on irrigation practice in the Central Coastal Area indicates that present irrigation efficien- cies generally range from 50 to 60 per cent. Addi- tional factors affecting the estimates of probable ulti- mate irrigation water service area efficiencies were related to the location and extent of presently unde- veloped irrigable lands, as well as to the increased cost of developing water. For purposes of illustra- TABLE 69 DISTRIBUTION OF MONTHLY WATER DEMANDS, CENTRAL COASTAL AREA (In per cent of seasonal total) Locality and purpose January Feb- ruary March April May June July August Sep- tember ( Ictolil'l Novem- ber Decem- ber Total Irrigation demand Pajaro Valley, 1947 and 1949 Salinas Valley Pressure Area, 1945_ Santa Maria Valley, 1938 Urban demand Santa Cruz, 1946 through 1948 Salinas, 1944 Monterey, 1949. . . 0.4 1.3 4.7 6.7 5.2 6.0 0.1 0.4 4.9 5.7 4.3 5.7 0.5 1.7 5.9 6.0 4.7 5.9 11.3 10.7 4.6 6.5 7.5 5.7 6.9 15.0 14.5 9.4 9.0 9.6 7.7 8.0 22.3 16.1 13.9 10.0 10.5 10.6 9.7 23.8 18.0 17.3 12.8 10.6 10.1 10.9 16.7 16.8 17.3 13.5 10.4 12.1 11.6 8.1 13.1 13.4 11.8 9.8 11.1 11.2 1.6 9.9 8.0 9.4 8.8 12.4 9.4 0.1 0.9 7.5 6.7 7.6 8.6 8.3 0.1 5.2 4.8 6.8 7.5 6.4 100.0 100.0 100.0 100.0 100.0 100.0 Santa Barbara, 1946 through 1952. 100.0 CENTRAL COASTAL AREA 117 tion, the weighted mean values of all irrigation water service area efficiencies within each hydrographic unit of the Central Coastal Area are presented in Table 70. TABLE 70 ESTIMATED WEIGHTED MEAN IRRIGATION WATER SERVICE AREA EFFICIENCY WITHIN HYDROGRAPHIC UNITS, CENTRAL COASTAL AREA (In per cent) Hydrographic unit Present Prob- Refer- ence number Name able ulti- mate 1 50 65 50 65 65 50 50 2 50 3 50 4 60 5 6 7 Lower Salinas Carmel . 65 50 50 8 60 50 9 65 10 70 80 70 70 11 65 12 50 WATER REQUIREMENTS As the term is used in this bulletin, water require- ments refer to the amounts of water needed to pro- vide for all beneficial uses of water and for irrecov- erable losses incidental to such uses. Those water requirements of the Central Coastal Area that are pri- marily nonconsumptive in nature are discussed in general terms in the ensuing section. Following this, water requirements of the area that are consumptive in nature are evaluated, both for present and for probable ultimate conditions of development. Requirements of a Nonconsumptive Nature The principal nonconsumptive water requirements of the Central Coastal Area are associated with the preservation and propagation of fish and wildlife, flood control, and repulsion of sea water from ground water basins. For the most part, such requirements for water are extremely difficult to evaluate other than in conjunction with definite plans for water resource development. Their consideration in this bulletin, therefore, is limited to discussion of their implications as related to planning for future devel- opment of water resources. So far as is known, there are no present require- ments in the Central Coastal Area for water for gen- eration of hydroelectric power nor for purposes of navigation. In view of prevailing water supply and topographic conditions, it cannot be foreseen that appreciable requirements of such nature will ever develop in the future. Fish and Wildlife. The fresh-water fishery of the Central Coastal Area is limited as compared to that of some other parts of California. Nevertheless, it is important to the recreational economy of the area, and the fishing enjoyed by sportsmen contributes sub- stantially to the State's recreational facilities. Sport fishing is largely confined to the streams. However, there are several reservoirs and a number of farm ponds that also offer considerable fishing opportunities. The reservoirs and farm ponds are stocked for the most part with warm-water fishes, principally black bass, bluegill, and catfish, although a few contain trout. The principal fishing is for adult steelhead rainbow trout that migrate annually from the sea to their spawning beds on the riffles of the fresh-water streams. Trout form resident populations in some of the suit- able permanent stretches of streams in this area, and, along with the young of the steelhead and some silver salmon, contribute to the fishery. Adult silver salmon migrate into several of the streams from the Monterey Bay area northward, and provide some sport fishing, particularly in the San Lorenzo River. Adult silver salmon reared in these streams are also taken by both sport and commercial fishermen in the ocean. The sport fishery in the streams of the Central Coastal Area could be greatly improved by mainte- nance of a suitable stream flow throughout the year. The runoff pattern of streams of the southern portion of the area is extremely erratic. Under present condi- tions, flow in some of the southern streams does not reach the ocean for periods up to several years. Main- tenance of fish life sufficient for sport fishing in such streams as the Santa Ynez, Santa Maria, and Carmel Rivers would require the upstream impoundment of flood flows and their release during summer and fall to sustain stream flow. Whether this possible water requirement can be met, in view of the limited avail- able water resources, is problematical. On the other hand, in the northern portion of the area, particu- larly in northern Santa Cruz County, local water resources considerably exceed probable ultimate re- quirements, and it is possible that flood flows may be conserved and later released to sustain stream flow for fishing during dry periods, without adversely affecting the economy of the area. At the request of the Division of Water Resources, a series of estimates was made by the California De- partment of Fish and Game of the stream flow at certain points in the more important streams of the Central Coastal Area required for the protection and maintenance of fish life. These streams were divided into four classes by the Division, according to the anticipated degree of water development for various beneficial purposes that might compete with recrea- tional or commercial fishing requirements. The sum- mer and Avinter stream flow requirements for fish life in Central Coastal Area streams of the appropri- I1H WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA ate classes, as estimated by the Department of Fish and Game, are listed in Appendix F. Although the mountains of the Central Coastal Area support a substantial wildlife and afford sport hunting to many tourists, the related water require- ments are quite small. This condition is expected to be maintained in the indefinite future. Migratory waterfowl frequent the coastal lagoons, and provide minor opportunities for sport hunters. It is probable that such fresh water as is required to maintain this habitat will always be available from waste and return flows. Flood Control. There is at present a material need for flood control in several localities of the Cen- tral Coastal Area, and it is anticipated that this need will increase with growth of the area. Only minor flood control works exist, and their effects on the developed water supply are extremely small. However, at least one major surface storage develop- ment involving flood control, the multipurpose San Lucas Project on the Salinas River, has been pro- posed. The presently authorized Winchester Ranch Reservoir, on the Nacimiento River, would offer sub- stantial flood control benefits if operated as a multi- purpose project. The Santa Maria Project is in the advanced planning stage. It includes the Vaquero Reservoir utilized for conservation and flood control, and the Santa Maria Valley levees for flood control. It is probable that additional projects of these types will be planned and constructed in the future. The nonconsumptive requirements for water imposed by such flood control works may be substantial, and must be given consideration in plans to meet water re- quirements. Subsurface Outflow From Ground Water Basins to Ocean. In recent hydrologic studies in the Salinas and Pajaro Valleys it was found that during periods of little or no pumping draft on the confined aquifers of the coastal ground water basins there is substantial surface outflow to the ocean. This constitutes an un- avoidable loss of the fresh-water supplies, and for purposes of inventory in the present investigation was construed as a nonconsumptive water requirement. It was estimated that the average subsurface outflow from the Salinas Valley, under the present pattern of pumping draft, is approximately 19,000 acre-feet per season, and from the Pajaro Valley approximately 2,000 acre-feet per season. Overdrafts are known to exist in coastal ground water basins of the Pajaro and Salinas Valleys, and resultant sea-water intrusion into the confined aqui- fers is becoming a critical problem. Other coastal ground water basins of the Central Coastal Area have present or potential overdrafts, and are in danger of similar sea-water intrusion. Studies now in progress indicate that subsurface outflow of fresh water from the confined aquifers to the ocean must be maintained in order to control this invasion of the economically important ground water basins, and to prevent de- gradation of quality of the ground water. Evaluation of the magnitude of this water requirement must await detailed hydrologic analysis under a specific plan of development and pattern of pumping draft. Requirements of a Consumptive Nature Estimates of present and probable ultimate water requirements of a consumptive nature within hydro- graphic units of the Central Coastal Area are pre- sented in Table 71. These mean seasonal values rep- resent the amount of water other than precipitation needed to provide for beneficial consumptive use of water on irrigated lands, farm lots, urban and sub- urban areas, and other water service areas, and for TABLE 71 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL REQUIREMENTS FOR WATER, CENTRAL COASTAL AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Approximate totals Name Refer- ence number Present Probable ultimate Present Probable ultimate Present Probable ultimate Present Probable ultimate Present Probable ultimate 1 Santa Cruz .__ 5,400 126,000 23,800 11,400 263,000 2,200 12,000 117,000 47,200 32,600 14,200 325,000 39,400 587,000 415,000 15,600 30,800 178,000 187,000 299,000 200,000 96,000 100 1,400 400 2,000 200 1,000 400 600 200 2,800 600 4,200 4,000 200 200 1,000 1,200 2,600 1,600 1,000 7,300 2,500 2,700 2,600 9,300 8,100 4,800 2,100 1,400 6,600 32,600 11,700 8,300 9,800 40,700 32,200 300 14,700 1,200 9,000 5,300 32,600 300 1,500 7,200 100 200 500 2,600 2,200 3,600 600 2,100 7,300 200 500 400 200 1,500 2,400 4,400 13.100 130,000 26,900 15,500 281,000 10,300 100 17,200 121,000 51,600 42,000 50,600 2 San Benito 340,000 3 48 300 4 603,000 5 467,000 6 48 200 7 „. Monterey Coast 31,800 8 _. San Luis Obispo 194,000 9 __ Carrizo Plains- . _ 190,000 10 Santa Maria . 312,000 11 Santa Ynez . _ _ . 209,000 12 Santa Barbara . 134,000 APPROXIMATE TOTALS.- 641,000 *2,217,000 6,100 19,600 47,400 198,000 14,600 23,200 709,000 *2,458,000 * Total reduced by 170,000 acre-feet of return water in bower Salinas Hydrographic Unit. CENTRAL COASTAL AREA 119 irrecoverable losses of water incidental to these uses. The estimates were derived from consideration of the heretofore presented estimates of consumptive use of applied water, and of water service area efficiencies of hydrographic units. In the Salinas Hydrographic Unit, extensive re-use in the lower unit of return water from the upper unit reduces the total require- ment for the hydrographic unit as a whole. Supplemental Requirements The present supplemental water requirement in each hydrographic unit of the Central Coastal Area was taken as equivalent to the estimated ground water overdraft when such was known to exist. Deficiencies in surface stream flow or surface storage capacity were not considered in the estimates of present supplemental requirements. The difference between estimated present and probable ultimate water re- quirements for each hydrographic unit plus the pres- ent supplemental requirement was taken as the meas- ure of the probable ultimate supplemental water requirement. Results of prior studies of the use of ground water in the Central Coastal Area indicate that overdrafts exist in ground water basins of the San Benito, Pa- jaro. Lower Salinas, Santa Maria, and Santa Barbara Hydrographic Units. In all these instances the use of ground water has intensified since the date of studies, and probably the overdrafts in most basins have increased. However, lacking specific knowledge of the amount of such increases, the original estimates were used in this bulletin. The present use of water in the Santa Cruz, Upper Salinas, Carmel, Monterey Coast, Carrizo Plains, and Santa Ynez Hydrographic Units is primarily by stream diversion or by ground water pumpage, without apparent overdraft. In these instances the yield of the present water supply de- velopment was assumed to be equal to the present requirement for water. The Upper and Lower Salinas Hydrographic Units are unique in the Central Coastal Area because an increase in consumptive use of water in the upper unit will decrease water supplies natur- ally flowing to the lower unit. Therefore, for pur- poses of this bulletin, the values of supplemental water requirement for the Upper and Lower Salinas Hydrographic Units were estimated under the as- sumption that each unit is a separate entity, and that water is now imported from the upper unit to the lower unit to meet present requirements in the latter. Such an assumption permits ready modifica- tion of the estimates of supplemental requirements as future water resource development may be planned or occur. However, 70 percent of the water lost in transportation to and deep percolation from the Up- per Salinas Hydrographic Unit would be available for re-use in the lower unit. Therefore, the total sup- plemental water requirement for the Salinas Basin is not necessarily the total of the supplemental re- quirements of the individual units. Construction of the Cachuma Project in the Santa Ynez Hydrographic Unit is in progress. By storage of flood waters of the Santa Ynez River, it was esti- mated that an additional 33,000 acre-feet of safe sea- sonal yield of water will be made available for im- port to the Santa Barbara Hydrographic Unit. For purposes of this bulletin, present supplemental water requirements were estimated without consideration of this import. However, it was assumed that under con- ditions of ultimate development the Cachuma Project would furnish the indicated import to the Santa Bar- bara Hydrographic Unit. Presented in Table 72 are the estimates of present and probable ultimate mean seasonal supplemental water requirement of hydrographic units of the Cen- tral Coastal Area. TABLE 72 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL WATER REQUIREMENTS, CENTRAL COASTAL AREA (In acre-feet) Hydrographic unit Present Reference number Name Probable ultimate 1 Santa Cruz. . . _ - 15,000 4,000 80,000 55,000 30,000 38,000 225,000 25,000 588,000 266,000 38,000 32 000 2 3 4 5 6_ 7 8, 177,000 190,000 246,000 158,000 89,000 9 10_ 11 12 APPROXIMATE TOTALS 184,000 *1 ,902,000 * Total reduced by 170,000 aere-feet of return water in Lower Salinas Hydrogiaplilc Unit. CHAPTER VI SOUTH COASTAL AREA The South Coastal Area, designated Area 4 on Plate 8, lies between latitudes 32.5° N. and 35° N., and com- prises the drainage areas of those streams discharg- ing into the Pacific Ocean between the southeastern boundary of the Rincon Creek watershed near the Santa Barbara-Ventura county line on the north and the Mexican boundary on the south. The portion of the drainage basin of the Tia Juana River lying within Mexico is not included in the area. All of Orange County and portions of the Counties of Kern, Los Angeles, Riverside, San Bernardino, San Diego, Santa Barbara, and Ventura lie within the boundaries of the South Coastal Area. The principal urban cen- ters constitute the large metropolitan areas within and adjacent to the Cities of Los Angeles and San Diego. To aid in hydrologic analyses, the South Coastal Area was subdivided into 10 hydrographic units, as delineated on Plate 8. The boundaries of these units generally follow topographic divides, with the excep- tion of certain boundaries of the Los Angeles and San Diego Hydrographic Units, also termed the Los Angeles and San Diego Metropolitan Areas, which were selected on the basis of the probable ultimate limits of intensive urbanization. Table 73 lists the 10 hydrographic units and their areas, and Table 74 presents the area of the portion of each county in- cluded within the South Coastal Area. The climate of the South Coastal Area is character- ized in the coastal regions by relatively mild tempera- tures and light precipitation, and in the more inland regions by somewhat wider temperature variations TABLE 73 AREAS OF HYDROGRAPHIC UNITS, SOUTH COASTAL AREA TABLE 74 AREAS OF COUNTIES WITHIN BOUND- ARIES OF SOUTH COASTAL AREA Hydrographic unit Reference number Name Acres 1 Ventura.. 168,000 2 3 Santa Clara-Calleguas Malibu .. 1,286,000 137,000 4 5 6... San Gabriel Mountains _ _ Upper Santa Ana. Los Angeles .. _ 307,000 1,450,000 1,186,000 7 8 San Juan Capistrano Santa Margarita-San Luis Rey 322,000 849,000 9 10 San Dieguito-Cottonwood San Diego 973,000 317,000 APPROXIMATE TOTAL 6,995,000 County Kern Los Angeles Orange Riverside San Bernardino San Diego Santa Barbara Ventura APPROXIMATE TOTAL Acres 1,300 1,768,000 503,000 1,198,000 647,000 1 ,939,000 5,100 934,000 6,995,000 and greater precipitation. Precipitation generally in- creases with elevation. The mean seasonal depth of precipitation at Los Angeles is about 15 inches, while at Kelly's Camp, at an elevation of 8,300 feet in the San Bernardino Mountains near the Los Angeles-San Bernardino county line, it is over 40 inches. Depth of seasonal precipitation on valley floor areas aver- ages about 15 inches, varying from about 10 inches to 20 inches, with valley floor areas adjacent to the mountains receiving the higher rainfall. Variation of precipitation from season to season is quite pro- nounced. At Los Angeles an unbroken precipitation record has been maintained since 1877. During this period the seasonal depth of precipitation has varied between extremes of 5.59 inches and 38.18 inches, averaging 15.43 inches. Precipitation occurs princi- pally during the winter months, about 90 per cent of the seasonal total generally occurring from November through April. The estimated mean seasonal natural runoff of streams in the South Coastal Area is about 1,227,000 acre-feet, or approximately 1.7 per cent of that for the entire State. The principal streams are the Ven- tura, Santa Clara, Los Angeles, San Gabriel, Santa Ana, Santa Margarita, San Luis Rev, San Dieguito, San Diego, and Tia Juana Rivers, which contribute a seasonal runoff of about 1,000,000 acre-feet on the average, or over 80 per cent of the total for the area. The largest stream, the Santa Ana River, has a mean seasonal runoff of 322,000 acre-feet, or about 26 per cent of the total for the South Coastal Area. Runoff is derived principally from rainfall and is character- ized by high peak flows of short duration. Many streams are intermittent, with practically all runoff occurring during the winter and spring months. For the area as a whole approximately 70 per cent of the (121) SOUTH COASTAL AREA 123 runoff occurs during the four months from January through April on the average. As shown on Plate 4, a total of 43 valley fill areas, which may or may not contain usable ground water, has been identified in the South Coastal Area. The most important of these from the standpoint of ground water utilization, are the basins located in the Upper Santa Ana. San Gabriel, and San Fernando Valleys, along the Santa Clara River and in the coastal plain at its mouth, and in the coastal plains of Los Angeles and Orange Counties. Practically all of the present regulation of runoff of the Santa Clara, Los Angeles, San Gabriel, and Santa Ana Rivers is pro- vided by these ground water basins. In general, aquifers of economic significance in ground water basins adjacent to the coast are confined by overlying impervious strata, while those in basins farther inland contain free ground water. Many of the ground water basins have experienced overdraft for many years past, and in most of the important basins adjacent to the coast overpumping has lowered piezometric levels below sea level, with resultant intrusion of sea water. Today the South Coastal Area is characterized by a rich and intensively irrigated agricultural develop- ment, by very large urban centers, and by an indus- trial development of national significance. The history of these developments dates back to the founding of the Spanish missions nearly two centuries ago. The first practice of irrigation in the South Coastal Area came with the founding of San Diego Mission by the Franciscan Fathers in 1769. Water from the San Diego River, originally obtained by surface diversion and later supplemented by wells dug in the river gravels, was used to irrigate fields surrounding the mission. Similar agricultural developments accom- panied the establishment of the Missions San Luis Rey, San Juan Capistrano, San Gabriel, San Fer- nando, and San Buenaventura in ensuing years. In 1833 the missions were secularized by the Mexican Government and the mission holdings and other lands were given to individuals in the form of large land grants, which were used primarily for raising live- stock. For many years after the secularization of the missions, there was no significant increase in the prac- tice of growing irrigated crops. It was not until the latter half of the nineteenth century that significant expansion of irrigated lands commenced. In 1851 the Mormons purchased the Rancho San Bernardino and soon were irrigating several hundred acres. During the following years, plantings of irrigated crops were made in many other parts of the South Coastal Area. Citrus crops were first raised commercially in the Upper Santa Ana Valley, and shipment of oranges to the east began in the 1880 's. Walnuts were first planted in Ventura County about 1880, and bean pro- duction began in the Oxnard Plain of this county in the 1890 's. Winter truck crops were first produced commercially near San Diego about 1910, and in about 1915 avocados and other subtropical fruits were in- troduced to this county. Figures published by the United States Bureau of the Census indicate that over 200,000 acres were irrigated in the South Coastal Area in 1900. By 1930, this figure had increased to over 600,000 acres. Since 1930 the area devoted to irrigated agriculture has remained fairly constant, the present gross irrigated area being about 650,000 acres, located chiefly on the coastal plains and in the interior valleys where water supplies have been avail- able. The most important crops presently include citrus and subtropical fruits, truck, nuts, alfalfa, and pasture. The principal centers of urban development are the Cities of Los Angeles and San Diego and adjacent areas, and the urban zone in the Upper Santa Ana Valley from Pomona to San Bernardino. Table 75 presents the 1940 and 1950 populations of the eight largest cities in the South Coastal Area according to the federal census, and 1954 population estimates. The 1954 populations shown for San Diego and San Bernardino are estimates by the planning commissions of these cities. The 1954 populations shown for the remaining cities are estimates by the Los Angeles County Regional Planning Commission, as of July, 1954. It should be noted that the estimated 1954 popu- lation of the City of San Diego includes about 63,000 military personnel. The historical growth of the City of Los Angeles is generally indicative of urban growth in the South Coastal Area. In 1850, four years after the occupation of Los Angeles by Americans, the population was only 1,610. However, by 1880 the population had in- creased to over 10,000. As a result of many factors, including the mild climate, a direct rail connection to the east, and the construction of Los Angeles Harbor in the 1880 's, the population grew to over 50,000 in 1890, and to over 100,000 in 1900. The rate of growth accelerated during the early decades of the present century, and, as shown in Table 75, the 1954 popula- tion of Los Angeles was estimated to be over 2,000,000. TABLE 75 POPULATION OF PRINCIPAL URBAN CENTERS, SOUTH COASTAL AREA City 1940 census 1950 census 1954 estimate Los Angeles 1,504,000 203,000 164,000 81,900 82,600 34,300 53,500 43,600 1,970,000 334,000 251,000 105,000 95,700 78,600 71,600 63,100 2,138,000 459 000 Long Beach. 283,000 Pasadena Glendale ... 116,000 114,000 Burbank 91,000 Santa Monica 76,000 San Bernardino. 81,000 Construction of excellent rail and port facilities, the discovery of oil, and the availability of a large labor pool, were important factors in the development of Los Angeles Harbor The Petroleum Industry in the South Coastal Area Courtesy State Division of Highways SOUTH COASTAL AREA 125 Los Angeles as an industrial center. Industrialization commenced largely in the years following the first World War, and was given even greater impetus by World War II. The 1947 Census of Manufactures by the United States Department of Commerce indicated that Los Angeles ranked fifth among cities of the United States in value added by manufacturing. It has been estimated that in 1953 the Counties of Los Angeles and Orange ranked third among industrial areas of the Nation, and that nearly one-third of the over two million employed persons in the two counties were engaged in manufacturing enterprises. Among the principal industries are automobile assembly, mo- tion picture production, food processing, petroleum production and refining, and the manufacture of air- craft, tires, apparel, and furniture. Associated with this industrial growth has been the growth of Los Angeles Harbor, which presently handles a total ton- nage exceeding that of any other Pacific Coast port. The historical population growth of the City of San Diego followed a similar pattern to that of Los Angeles. The growth was slow until the latter part of the nineteenth century, being in large part retarded by lack of sufficient firm water supplies and adequate transportation facilities. The population of the city in 1880 was less than 3,000. However, in the ensuing decade the entrance of the first railroad into the area, and the initiation of several water development plans, overcame these handicaps, and the population had grown to over 16,000 by 1890. After about 15 years of relative stability, the city then began a generally steady but frequently accelerated growth. This growth was influenced by the efforts of ' ' booster ' ' clubs which were first organized about 1900, by the publicity cre- ated by the world expositions held there in 1915 and 1935, and by the expansion of military establishments and aircraft manufacturing occasioned by World War II. The large population centers of the South Coastal Area, and the tourist trade attracted to these cen- ters, have occasioned the establishment of many resort and recreational areas, principally in the mountains and along the coast. Many of the mountain recrea- tional areas are located within the boundaries of the Los Padres, Angeles, San Bernardino, and Cleveland National Forests, and many of the beach areas are under the jurisdiction of the Division of Beaches and Parks of the State Department of Natural Re- sources. There are numerous military reservations in the area, the most important of which are under Depart- ment of the Navy jurisdiction. These include training, air, and repair facilities at San Diego, several marine bases, the largest of which is Camp Pendleton, and two major base's in Ventura County, the larger being a guided missile test center. Army and Air Force establishments are distributed through the area, and the principal installation is March Air Force Base in Riverside County. The most significant recent trend in land use within water service areas of the South Coastal Area has been the urbanization which is still occurring at a rapid rate. This development has largely taken place on agricultural lands immediately adjacent to exist- ing urban areas. It is considered probable that most of the future urbanization will also occur on lands presently devoted to agricultural use. Increase in the area of irrigated lands will probably be dependent upon the availability of additional water supplies developed outside the South Coastal Area, and will occur both by application of water to areas presently dry farmed, and by bringing under cultivation lands not presently farmed due to lack of an adequate water supply. A proportional increase in areas devoted to recreation will undoubtedly accompany future in- creases in population. At the present time the principal water supplies in the South Coastal Area are obtained by pumping from underlying ground water basins, diversion from surface reservoirs, and importation of water from the Colorado River and from the Owens River and Mono Basin. Although large amounts of water are obtained by individuals who pump from ground water, most of the lands requiring water are served by a multitude of agencies, both large and small. The principal water service agencies in the South Coastal Area, and the number of domestic services and irrigated areas served by each, are listed in Appendix B. The earliest development of water supplies in the South Coastal Area consisted of the diversion of natural flow of streams, supplemented by wells dug in the river gravels. The water so obtained was con- veyed to nearby places of use by ditch systems, of which remnants still exist. Because of the erratic nature of the natural stream flow, these unregulated sources of supply were found to be inadequate to serve the increasing needs for water in the latter years of the nineteenth century. In 1884, Bear Valley Reservoir was constructed on a tributary of the Santa Ana River. This marked the first significant use of surface storage to regulate water supplies in the South Coastal Area. Although extensive control of surface supplies has taken place subsequently, the underlying ground water basins have become the most important source of supply in the Upper Santa Ana, San Fernando, and San Gabriel Valleys, in the coastal plains of Los Angeles and Orange Counties, and throughout Ventura County. Prior to 1900 thou- sands of wells, many of them artesian, were developed to supply both irrigation and domestic needs. As draft on the ground water supplies increased, the limits of artesian areas decreased in size and ground water levels began dropping, resulting in an increas- 126 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA ing use of deep-well turbine pumps to extract water from greater depths. At the present time, by far the largest portion of local supplies used in the Santa Clara-Calleguas, Los Angeles, and Upper Santa Ana Hydrographic Units continues to be obtained by pumping from ground water. Ground water basins in San Diego County are of lesser importance as a source of water supply, be- cause of their insufficient storage capacity to provide the desired degree of regulation of the erratic stream flow. Therefore, water users were soon forced to turn to surface storage developments to supply their increasing needs. The first plans for storage develop- ments were initiated by numerous small companies, which seldom had a life of more than a few years. Cuyamaca Reservoir was constructed in 1887 by the San Diego Flume Company, and Sweetwater Reser- voir in 1888 by the San Diego Land and Town Com- pany. Since that date, Morena, Lower Otay (formed by Savage Dam), Hodges, Barrett, Henshaw, El Capitan, San Vicente, Loveland, and Sutherland Reservoirs have been constructed by various organ- izations to meet increasing water requirements. At the present time, Cuyamaca Reservoir is owned by the La Mesa, Lemon Grove and Spring Valley Irriga- tion District ; Sweetwater and Loveland Reservoirs by the California Water and Telephone Company, and Lake Henshaw by the Vista Irrigation District. Of the remaining cited reservoirs, all of which are presently owned by the City of San Diego, Morena and Lower Otay were purchased from the Southern California Mountain Water Company in 1913, Hodges was purchased from the San Diego County Water Company in 1925, and Barrett, El Capitan, San Vicente, and Sutherland were constructed by the city. The smallest of the foregoing reservoirs in San Diego County, Cuyamaca, has a storage capacity of about 11,600 acre-feet, and the largest, Lake Hen- shaw, has a capacity of about 194,000 acre-feet. Their aggregate storage capacity is about 677,000 acre-feet. As early as 1900 it became apparent that local water supplies would not be sufficient to satisfy the needs of the rapidly growing City of Los Angeles, and studies were begun to locate additional sources of water. After several years of investigation, the city authorized construction of an aqueduct from the Owens River in the Lahontan Area. Construction of the Los Angeles Aqueduct was initiated on Sep- tember 20, 1907, and was completed on November 5, 1913. The initial project included diversion struc- tures and a 233-mile conduit to the San Fernando Valley. In 1910, additional bonds were issued for the purpose of financing the generation of electric power along the aqueduct. In 1940, the system was extended northward to the Mono Basin, and subsequently water from this watershed has been conveyed through the aqucdiicl. The prcsenl average capacity of the Los Angeles Aqueduct is estimated to be about 320,000 acre-feet per season. During the decade from 1920 to 1930, the City of Los Angeles and other communities in southern Cali- fornia foresaw the need of additional supplemental water for their rapidly expanding service areas. Studies of the possibilities of importing Colorado River water were initiated by the Los Angeles De- partment of Water and Power, and in 1928 were turned over to the newly formed Metropolitan Water District of Southern California. After extensive studies of possible alternative conduit routes to the South Coastal Area, a final alignment was selected and construction was started in 1933. First delivery of water from the Colorado River Aqueduct was made in 1941 to the City of Pasadena. Waters of the Colo- rado River, regulated by Lake Mead created by Hoover Dam, are diverted to the aqueduct from Lake Havasu behind Parker Dam. From Lake Havasu, the conduit extends in a generally westerly direction a distance of 242 miles to terminal storage in Lake Mathews, near Riverside, and thence northwesterly about 38 miles to the La Verne softening plant in Upper San Gabriel Valley. Under the provisions of the Colorado River Com- pact and the Boulder Canyon Project Act, the State of California claims the right to 5,362,000 acre-feet of water from the Colorado River each year. By the terms of the 1931 Seven-Party Water Agreement, executed by California agencies using Colorado River water, the Metropolitan Water District of Southern California was allotted 1,100,000 acre-feet of this amount, and an additional 112,000 acre-feet were allotted to the City and County of San Diego. A con- tract with the Secretary of the Interior, signed in 1930, and amended in 1931, provides for delivery to the district of their entitlements under the pro- visions of the Seven-Party Water Agreement. Dur- ing the fiscal year 1949-50, which is the period upon which present requirements tabulated in this bulletin are based, about 165,000 acre-feet of Colorado River water were delivered to member agencies by the dis- trict. The rights of the City and County of San Diego were merged upon the formation of the San Diego County Water Authority on June 9, 1944, which latter agency became a member of the Metro- politan Water District on December 17, 1946. The year 1947 saw the completion of the first barrel of the San Diego Aqueduct. The aqueduct takes water from the Colorado River Aqueduct at a point in San Jacinto Valley, and conveys it to San Vicente Reser- voir on a tributary of the San Diego River. The second barrel of the San Diego Aqueduct was dedicated on October 2, 1954, and it is estimated by the San Diego County Water Authority that the capacity of the aqueduct is now approximately 215 second-feet. Plate 15 depicts the historical import of water to the South Coastal Area by the City of Los Angeles SOUTH COASTAL AREA 127 and the Metropolitan Water District of Southern Cali- fornia. In summary, it should be emphasized that despite the presence of a tremendous urban and industrial development, agriculture remains a major economic activity of the South Coastal Area. Water require- ments for other uses, however, are expected to sur- pass that for agriculture in the near future. The cur- rent encroachment of urban types of development onto agricultural lands will undoubtedly continue in the future. In addition, large areas of irrigable lands presently in the native state will probably be brought under cultivation if and when new sources of water supply become available. In order for the South Coastal Area to be able to realize its large potential, additional water must be made available, probably from sources outside the area. In this connection, it has been found that urbaniza- tion of an area previously occupied by irrigated agri- culture significantly affects the water requirements of the area. When irrigated agriculture is superseded by an unsewered urban area, and there is opportunity for re-use of the unconsumed portion of the applied water, urban requirements may be slightly less than those for the formerly irrigated area. Export of sewage to the ocean, however, may increase the urban requirement substantially over that previously neces- sary for the maintenance of irrigated agriculture. At present, there is no water utilized in the South Coastal Area for navigation, and but negligible amounts are utilized for hydroelectric power genera- tion and for the preservation and propagation of fish and wildlife. These conditions are expected to main- tain in the future. There have been large public expenditures for flood protection, and there is in excess of 400,000 acre-feet of storage capacity in exist- ing flood control reservoirs, the largest being Prado on the Santa Ana River with a storage capacity of 223,000 acre-feet. Many miles of stream channel are lined for flood control purposes, and the extension of such improvement is planned for the future. Addi- tional flood control works will be necessary in the future to protect the intensive urban and agricultural developments. The remainder of this chapter presents available data and estimates concerning the nature and extent of present and probable ultimate water requirements in the South Coastal Area. PRESENT WATER SERVICE AREAS As a necessary step in estimating present water requirements in the South Coastal Area, determina- tion was made of the location, nature, and extent of present irrigated and urban and suburban water service areas. In the remainder of the area, relatively minor miscellaneous water service areas were not classified in detail regarding area and type of use, but consideration was given to this water service in estimating the present water requirement. Irrigated Lands It was determined that an average of about 617,000 acres in the South Coastal Area are irrigated each year under present conditions of development. This constitutes about 9 per cent of the total irrigated lands in California. There are large acreages of citrus and subtropical fruits throughout the area, these crops occupying nearly half of all the irrigated lands. Truck crops are produced in large quantity in the Upper Santa Ana Valley and in the Los Angeles Metropolitan Area, and to a lesser extent in the re- mainder of the South Coastal Area. Other important irrigated crops are nuts, alfalfa, pasture, and beans. The determination of areas devoted to irrigated agriculture was based upon land use surveys con- ducted by the Division of Water Resources during the years from 1948 to 1951, and recent land use surveys made by other public agencies. Dates of field mapping and sources of data are included in Ap- pendix D. The crop grouping employed to segregate crops of similar water use varied somewhat in the various surveys. For purposes of presentation in this bulletin, the crops were generally grouped as follows : Alfalfa Pasture Walnuts Hay, seed, and pasture -Grasses and legumes, other than alfalfa, used for livestock for- age, and irrigated grass in parks, cemeteries, golf courses, etc. Orchard Deciduous fruit, olives, and nuts other than walnuts Citrus and subtropical Oranges, lemons, grapefruit, and avocados Truck crops Beans Hay and grain Miscellaneous _ .Intensively cultivated fresh veg- etables, including tomatoes, lettuce, artichokes, brussels sprouts, cabbages, carrots, pep- pers, broccoli, corn, beets, and berries. _A11 varieties of dry beans _Hay other than alfalfa and all grain crops .Other crops, including nursery, flowers, and vineyards. A deviation from the above crop grouping occurs in the Upper Santa Ana Valley and the Los Angeles Metropolitan Area, where beans were included as a part of the truck classification. The areas presently devoted to irrigated agricul- ture in hydrographic units of the South Coastal Area Urban Development and Agriculture Near San Bernardino Courtesy San Bernardino County Board of Trade Irrigated Lands in Ventura County SOUTH COASTAL AREA 129 are summarized in Table 76. Table 77 lists the irri- gated areas by counties. Areas presented in the two tables include irrigated agricultural lands within the boundaries of federal reservations, such as military reservations, Indian reservations, and national forests. Urban and Suburban Water Service Areas The gross area presently occupied by urban and suburban types of land use in the South Coastal Area was determined to be about 550,000 acres. In most hydrographic units of the area detailed surveys were made as to the lands devoted to the various urban and suburban types of land use. However, in the San Juan Capistrano, Santa Margarita-San Luis Rey, and San Dieguito-Cottonwood Hydrographic Units no detailed segregation of the urban and sub- urban lands by land use type was made, and only the total urban and suburban area was determined. The San Gabriel Mountains Hydrographic Unit lies entirely within the Angeles National Forest, and area! figures for land use other than irrigated agri- culture were not obtained. Since in most of the area a differentiation between farm lots and the suburban type of land use was almost impossible, farm lots were included in the area mapped as rural residence, and were tabulated with the present urban and suburban area. Also, since in many cases the urban and suburban areas in mili- tary reservations were mapped in accordance with their specific type of land use, these areas were tabu- lated with urban and suburban water service areas. Tables 78 and 79 list the areas presently occupied by urban and suburban types of land use in hydro- graphic units and counties, respectively, of the South Coastal Area. Due to the varying land use classifica- tions employed in different surveys, these classifica- tions were combined into the categories of residential, commercial, industrial, miscellaneous, and lands not requiring water service, for presentation in this bulle- tin. The miscellaneous areas include lands occupied by schools, institutions, rural residences, dairies, hog farms, chicken ranches, and urban types of military areas. Areas listed as not requiring water service consist of inclusions in the gross urban area of streets, vacant lands, oil fields, etc. TABLE 76 AREAS OF PRESENTLY IRRIGATED LANDS WITHIN HYDROGRAPHIC UNITS, SOUTH COASTAL AREA (In acres) Refer- ence num- ber Hydrographic unit Name Alfalfa Pasture Orchard Wal- nuts Citrus and sub- tropical Truck crops Beans Hay and grain Miscel- laneous crops Ap- proxi- mate net irri- gated area In- cluded non- water service areas A P - proxi- mate gross area 1 2 3 4 5 6 7 8 9 10 Ventura Santa Clara-Calleguas Malibu San Gabriel Mountains Upper Santa Ana Los Angeles San Juan Capistrano Santa Margarita-San Luis Rey__. San Dieguito-Cottonwood San Diego APPROXIMATE TOTALS 200 8,600 12,900 15,200 300 2,800 1,000 1,500 300 1,400 300 16,900 16,600 100 2,300 1,700 1,600 200 600 100 13,900 2,700 600 1,200 400 600 17,300 13,600 10,100 100 600 400 200 2,400 40,500 100 81,000 122,000 2,800 8,000 14,700 8,000 200 10,200 500 200 32,200 67,300 1,100 4,300 1,600 7,100 33,300 1,300 100 300 800 12,200 3,600 3,100 100 400 6,000 3,500 300 700 300 400 3,900 113,000 900 300 189,000 241,000 6,000 22,500 21,000 19,500 200 5,900 100 9,700 12,700 600 1,800 2,100 1,900 4,100 119,000 1,000 300 198,000 254,000 6,600 24,300 23,100 21,400 42,500 41,200 19,700 42,900 279,000 125,000 35,000 19,800 11,600 617,000 35,000 652,000 TABLE 77 AREAS OF PRESENTLY IRRIGATED LANDS WITHIN COUNTIES, SOUTH COASTAL AREA (In acres) County Alfalfa Pasture Orchard Walnuts Citrus and sub- tropical Truck crops Beans Hay and grain Miscel- laneous crops Approxi- mate net irrigated area Included nonwater service areas Approxi- mate gross area 14,400 5,800 11,600 3,200 3,300 4,200 14,200 3,600 10,900 6,600 4,500 1,400 2,700 500 7,400 6,600 2,000 500 9,700 2,000 6,300 6.000 1,100 17,800 59,000 73,300 26,300 47,300 30,700 43,000 27,700 43,300 18,100 14,100 13,400 8,100 3,400 700 12,000 2,800 100 800 3,400 300 2,800 3,200 1,700 200 135,000 129,000 95,400 89,800 58,500 109,000 7,100 7,000 4,700 4,700 5,700 5,800 142,000 136,000 1,700 33,300 100,000 San Bernardino 94,500 64,200 Ventura 115,000 APPROXI- MATE TOTALS.... 42,500 41,200 19,700 42,900 279,000 125,000 35,000 19,800 11,600 617,000 35,000 652,000 5— 99S01 130 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 78 PRESENT URBAN AND SUBURBAN AREAS WITHIN HYDROGRAPHIC UNITS, SOUTH COASTAL AREA (In acres) Hydrographic unit Area requiring water service Area not requiring water service Approximate gross area Refer- ence number Name Residential Commercial Industrial Miscellaneous Subtotal 1 2 - Ventura .. . 1,600 4,000 500 200 600 100 400 400 500 3,300 100 2,700 8,300 700 4,800 13,500 800 7,500 21,800 3 4 Malibu _ . . . .. 1,500 5 - - 6 7. ... Upper Santa Ana Los Angeles 28,000 163,000 4,000 19.600 3.100 20,200 1.100 41,500 1,800 3,100 2,700 5,300 36,200 244,000 1.800 3,100 2,700 25,200 26.700 155,000 700 1,400 1,200 18,100 112,900 399,000 2,500 8 4,500 9-. 3,900 10.-- 17,800 1.800 300 43.300 APPROXIMATE TOTALS 215,000 26.300 24,400 59,400 325,000 222,000 547,000 TABLE 79 PRESENT URBAN AND SUBURBAN AREAS WITHIN COUNTIES, SOUTH COASTAL AREA (1 n acres) County Area requiring water service Area not requiring water service Approximate gross area 237,000 15,300 14,200 19,300 31,000 8,600 148,000 12,700 9,100 15.200 20,600 16,400 385,000 Orange . 28.000 23,300 34,500 51,600 25,000 APPROXIMATE TOTALS.. 325,000 222,000 547,000 Unclassified Areas The remainder of the South Coastal Area, compris- ing- those lands not included in either the irrigated or urban and suburban classifications as regards water service, constitutes about 5,800,000 acres, or over 80 per cent of the total land area. Included in these remaining lands are about 1,200 acres actually requiring water service at the present time, but which were not classified in detail as to the nature of their water utilization. Portions of the Los Padres, Angeles, San Bernar- dino, and Cleveland National Forests, occupying an area of about 3,200 square miles, or about 2,000,000 acres, are included within the boundaries of the South Coastal Area. An estimated 5,900 acres of irri- gated agriculture in the national forests, lying pri- marily along the lower slopes of the mountains and within the mountain valleys, are included in the figures of Tables 76 and 77. Unclassified lands in the national forests requiring water service include camp grounds and other developed areas, which may have substantial water requirements during the summer inont lis. There are 31 beaches and parks, including about 37,000 acres, in the South Coastal Area maintained by the Division of Beaches and Parks of the State Department of Natural Resources. The relatively small developed areas of these recreational facilities, like the recreational areas in the national forests, do not have a sustained annual demand for water but do require a supply during the summer months for domestic service for camp and picnic areas. Summary Present water service areas within hydrographic units of the South Coastal Area are summarized in Table 80, and present water service areas within the counties in Table 81. TABLE 80 SUMMARY OF PRESENT WATER SERVICE AREAS WITHIN HYDROGRAPHIC UNITS, SOUTH COASTAL AREA (In acres) Hydrographic unit Reference number 1 2 3 4 5 6 7 8 9 10 Name Ventura Santa Clara-Calleguas Malibu San Gabriel Mountains Upper Santa Ana I .i is Angeles San Juan Capistrano Santa Margarita-San Luis Rey San Dieguito-Cottonwood San Diego Subtotals- Irri- gated lands 4,100 19,000 1,000 300 98.000 54,000 6,600 24,300 23.100 21,400 652.000 LJrban and sub- urban areas 7,500 21.800 1,500 62,900 399,000 2,500 1,500 3,900 43,300 547,000 Unclassified areas receiving water service - APPROXIMATE TOTAL Approxi- mate tc.tal 11,600 141,000 2,500 300 261,000 653,000 9,100 28,800 27,000 64,700 1,199,000 1,200 Jin o SOUTH COASTAL AREA 131 TABLE 81 SUMMARY OF PRESENT WATER SERVICE AREAS WITHIN COUNTIES, SOUTH COASTAL AREA (In acres) County Los Angeles Orange Riverside San Bernardino. San Diego Ventura Irrigated lands 142,000 136,000 100,000 94,500 64,200 115,000 Subtotals 652,000 Unclassified areas receiving water service APPROXIMATE TOTAL Urban and suburban areas 385,000 28,000 23,300 34,500 51,600 25,000 547,000 Approximate total 527,000 164,000 123,000 129,000 116,000 140,000 1,199,000 1,200 1,200,0(1(1 PROBABLE ULTIMATE WATER SERVICE AREAS To aid in estimating ultimate water utilization in the South Coastal Area, projections were first made to determine the probable ultimate areal extent of irrigated crops and of urban and suburban types of land use. It was assumed that the remainder of the area, referred to as "other water service areas," will ultimately received water service commensurate with its needs. In the determination of ultimate land use, certain assumptions were made as to the ultimate disposition of lands presently within military reservations. Mili- tary bases in and adjacent to metropolitan areas which are now occupied by predominately urban types of land use were assumed to remain intact, and the land use was tabulated with the gross urban area. Irrigable lands within military reservations in other areas were included with the tabulations of total irrigable area, and any lands suitable for urbani- zation were included with the gross urban area. Irrigated Lands It was assumed that ultimately all lands in the South Coastal Area that are suitable for irrigated agriculture, and not then occupied by urban and sub- urban developments, would be irrigated. This gross irrigable area was estimated, with the aid of data from the land classification surveys, to be about 1,156,000 acres, after deductions were made for other- wise irrigable lands assumed to be ultimately urban- ized. An estimated 36,000 acres of the gross area rep- resent lands expected to be occupied by farm lots, and an additional 96,000 acres represent the included nonwater-using lands such as roads, railroads, non ir- rigable lands, etc. The remaining 1,021,000 acres rep- resent the average area estimated to be irrigated each year under ultimate conditions of development. Table 82 lists the estimates of ultimate irrigable areas in TABLE 82 PROBABLE ULTIMATE AREAS OF IRRIGATED LANDS WITHIN HYDROGRAPHIC UNITS, SOUTH COASTAL AREA (In acres) Hydrographic unit Gross irrigable area Farm lots Included nonwater service area Approxi- mate net irrigated :ilr;i Ref- erence num- ber Name 1 2 3 4 Ventura. Santa Clara-Calle- guas Malibu San Gabriel Mountains . Upper Santa Ana Los Angeles - San Juan Capistrano- Santa Margarita-San 5,600 161,000 3,000 300 371,000 50,300 91,100 222,000 230,000 22,200 300 8,000 200 4,700 11,200 11,400 600 13,800 300 4,700 139,000 2,500 300 5 6 33,200 338,000 50,300 7 8 8,100 19.900 20,500 78,300 191,000 9 10 . San Dieguito- Cottonwood 198,000 "",200 APPROXI- MATE TOTALS 1,156,000 35,800 96,400 1,024,000 Included in "Urban and Suburban Area." TABLE 83 PROBABLE ULTIMATE AREAS OF IRRIGATED LANDS WITHIN COUNTIES, SOUTH COASTAL AREA (In acres) County Los Angeles Orange Riverside San Bernardino San Diego Ventura APPROXIMATE TOTALS Gross irri- gable area 82,700 61,600 337.000 110,000 437,000 128,000 1,156,000 Farm lots 2,100 2,500 4.000 20.800 6,400 35,800 Included nonwater service area 3,900 4,300 31,000 9,100 37,000 ] 1,100 96 100 i.pproxi mate net irrigated area 76.700 54,800 302,000 101.000 379.000 111,000 1,024,000 » Included in "Urban and Suburban Area." hydrographic units of the Smith Coastal Area, and Table 83 presents these data by counties. It will be noted that in the Los Angeles, San Diego, and San Gabriel Mountains Hydrographic Units the net ultimate irrigated area is the same as the gross irrigable area. It is anticipated that in the two metro- politan areas the ultimate irrigated areas will prob- ably consist of inclusions within predominately ur- banized areas. Under these circumstances farm lots and the inclusions cited in the preceding paragraph will be a part of the urban area. In the San Gabriel Mountains Hydrographic Unit the forecast of ulti- mately irrigated lands was based upon estimates of the United States Forest Service, which indicated net irrigated areas only. From historical collection of Union Title Insurance and Trust Company, San Diego, California Urban Growth in San Diego Metropolitan Area SOUTH COASTAL AREA 133 To aid in estimating the probable ultimate water requirements, a crop pattern applicable to the prob- able ultimate net irrigated area was forecast. It is recognized that future developments may indicate that this crop pattern may be somewhat in error, both as to the portion of the probable ultimate irrigable area in the South Coastal Area devoted to each crop group, and as to the distribution of the area of each crop group between hydrographie units. However, it is felt that the magnitude of the ultimate water requirement would not be seriously affected. Table 84 presents this estimated crop pattern for the South Coastal Area. Urban and Suburban Water Service Areas It is considered probable that the present trend of rapid urbanization in certain portions of the South Coastal Area will continue in the future. In estimates for this bulletin, it was assumed that urban and sub- urban types of land use ultimately will occupy all lands in the Los Angeles and San Diego Hydro- graphic Units, except for scattered small agricultural areas and those lands topographically unsuited for development. Consideraton of present trends in Ven- tura County and in the Upper Santa Ana Valley indicates that large portions of these regions will ulti- mately be urban in character. It was assumed that this urbanization will take place almost entirely on lands classified as irrigable. With increasing population in the South Coastal Area, it is probable that there will be a proportionate increase in urban beach communi- ties, such as those presently expanding along the southerly portion of the coast line of Orange County. It was assumed that in the future more of this type of development will take place along the coast line adjacent to the Santa Monica Mountains, and all along the coast between Los Angeles and San Diego. It is probable that in the remainder of the South Coastal Area, urban and suburban development will, in general, be associated with agricultural pursuits, and it was assumed that such urban growth in the future will be proportional to increase in adjacent agricultural areas. Areas estimated to be ultimately occupied by the various urban land use types were determined by applying percentage factors to the de- termined ultimate gross urban and suburban area, the factors being based upon present urban land use patterns and expected future changes. As has been previously mentioned, estimates of the areas in mili- tary reservations occupied by urban types of land use are included in those of the gross urban area. In the determination of probable ultimate water service areas, the area occupied by farm lots was included as a portion of the gross irrigable area. Therefore, the estimate of probable ultimate gross urban and subur- ban water service area does not, as was the case in the present land use pattern, include farm lots. Table 85 presents the probable ultimate pattern of land use in urban and suburban water service areas in hydrographie units, and Table 86 presents esti- mated probable ultimate gross urban and suburban areas in counties of the South Coastal Area. Other Water Service Areas The remaining 4,228,000 acres of the South Coastal Area, not included in either the ultimate irrigated or urban and suburban water service areas, were not classified in detail regarding the nature of their probable ultimate water service. It was assumed that these "other water service areas" will be ultimately served with water commensurate with their needs. Included in ' ' other water service areas ' ' are developed areas within the national forest boundaries (except for irrigated lands, the areas of which are included in Tables 82, 83, and 84), state beaches and parks, and scattered recreational, residential, and indus- trial developments not included in the probable ulti- mate urban and suburban water service area. The TABLE 84 PROBABLE ULTIMATE PATTERN OF IRRIGATED CROPS, SOUTH COASTAL AREA (In acres) Hydrographie unit Alfalfa Pasture Orchard Walnuts Citrus and sub- tropical Truck crops Beans Hay and grain Miscel- laneous crops Approxi- Reference number Name mate total 1 Ventura _ 800 10,000 800 47,300 5,700 9,000 36,100 35,000 1,900 700 1,000 100 30,500 800 2,700 8,900 14,800 400 900 16,900 100 23,500 2,500 300 2,900 5,700 200 2,300 47,800 200 105,000 23,600 32,500 36,500 67,700 9,100 4,700 2 Santa Clara-Calleguas. 9,600 100 31,100 6,700 3,500 3,200 4,200 1,700 15,900 1,300 200 67,200 6,600 16,000 37,800 39,900 8,100 20,700 200 16,900 139,000 3 Malibu 2,500 4 San Gabriel Mountains __ 2,000 10.400 17,100 22,400 300 28.100 300 900 37,700 1,400 4,700 2,100 3,000 11.200 6,600 500 300 5 Upper Santa Ana 338,000 6 7 Los Angeles 50,300 78,300 8 9 10 Santa Margarita-San Luis Rey__ San Dieguito-Cottonwood San Diego 191.000 198,000 22,200 APPROXIMATE TOTALS. _ 60,100 146,000 59,900 53,000 325,000 193,000 72,900 68,600 45,000 1,024,000 134 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 85 PROBABLE ULTIMATE URBAN AND SUBURBAN AREAS WITHIN HYDROGRAPHIC UNITS, SOUTH COASTAL AREA (In acres) Hydrographic unit Area equiring water service Area not requiring water service Approximate gross area Refer- ence number Name Residential Commercial Industrial Miscellaneous Subtotal 1 . 11,800 49,500 14,000 1.100 4,800 1,100 600 5,000 800 4,400 500 14.300 63,700 15,600 6,200 24,700 7,200 20,500 2 88,400 3 Malibu - 22,800 4 5.. 131,000 443,500 17,600 22,200 17,200 97,200 8,600 61,200 1,500 2,000 1,600 9,600 13,700 74,700 1,900 7,400 119,000 700 1,000 800 21,800 161,000 698,000 19,800 25,200 19,600 131,000 73,300 255,000 8,200 9,500 6,900 72,200 234,000 6 7 . ... 8 9 10 Los Angeles San Juan Capistrano Santa Margarita-San Luis Rey _ San Dieguito-Cottonwood 953,000 28,000 34,700 26,500 203.000 APPROXIMATE TOTALS 804,000 91,500 95,900 156,000 1,148,000 463,000 1,611,000 TABLE 86 PROBABLE ULTIMATE URBAN AND SUB- URBAN AREAS WITHIN COUNTIES, SOUTH COASTAL AREA (In acres) County Los Angeles Orange Riverside San Bernardino San Diego Ventura APPROXIMATE TOTAL Gross area 726,000 271,000 89,800 147,000 269,000 108,000 1.611.000 greatest portion of these lands are in areas topo- graphically or otherwise unsuitable for intensive de- velopment. As shown in Table 87, "other water serv- ice areas" were divided for convenience in estimating water utilization into those portions inside and out- side of national forests, and above and below eleva- tion 3,000 feet. Summary Table 88 presents a summary of probable ultimate water service areas, segregated into irrigated, urban and suburban, and other water service areas. UNIT VALUES OF WATER USE Unit seasonal values of water use in the South Coastal Area were determined in accordance with the methods and procedures described in Chapter II. Unit values of urban water use were based upon spe- cial studies conducted in the Los Angeles and San Diego Hydrographic Units. Data employed in de- termination of unit values of water use for irrigated crops included the results of studies conducted by various public agencies and records of water deliver}- supplied by numerous water service agencies. TABLE 87 OTHER WATER SERVICE AREAS UNDER PROBABLE ULTIMATE CONDITIONS, SOUTH COASTAL AREA (In acres) Hydrographic unit Reference Dumbei 1 2 3 4 6 7 8 9 10 Name i Santa Clara-Calleguas Malibu San Gab] iel Mountains Upper Santa Ana Los \i)"il' ■' i apistrano. i ii gai ita San I iuis Rey... San 1 >ieguito-< lottonwood APPROXIMATE TOTALS Inside national forests, monu- ments, and military reservations Above 3,000-foot elevation 40,700 457,000 212,000 419,000 8,100 13,200 91,400 155,000 1,397,000 Below 3,000-foot elevation 41,200 181,000 95,300 76,000 20,800 75,200 21,400 127,000 i;:;n,[)[io Outside national forests, monu- ments, and military reservations Above 3,000-foot elevation 52,600 400 33,700 1,000 131,000 95,500 314,000 Below 3,000-foot elevation 59,700 346,000 1 1 1 ,000 316,000 153,000 115,000 348,000 339,000 91,600 1,879,000 Approximate total 142,000 1 ,037,000 111,000 307,000 845.000 183,000 203,000 592,000 716,000 111,600 4,228,000 SOUTH COASTAL AREA 135 TABLE 88 SUMMARY OF PROBABLE ULTIMATE WATER SERVICE AREAS, SOUTH COASTAL AREA (In acres) Hydrographio unit Irrigable lands Urban and suburban areas Other water service areas Refer- ence num- ber Name Approxi- mate total 1 2 Ventura . Santa Clara- 5.600 161.000 3,000 300 371,000 50,300 91,100 222,000 230,000 22,200 20,500 88,400 22,800 142,000 1 .037,000 111,000 307,000 xi;,, ni in 183,000 203,000 592,000 716,000 91,600 168,000 1,286,000 137,000 307,000 3 4 Malibu San Gabriel Moun- 5 6 7 8 9.... 10 Upper Santa Ana Los Angeles San Juan ( 'apistrano. Santa Margarita- San Luis Rey San Dieguito- Cottonwood San Diego APPROXIMATE TOTALS 234,000 953,000 28,000 34,700 26,500 203,000 1,450,000 1,186,000 322,000 849,000 973,000 317,000 1,156,000 1,611,000 4,228,000 6,995,000 Irrigation Water Use Unit seasonal values of consumptive use of water by irrigated crops were in general determined in ac- cordance with the methods of Chapter II. In certain cases, it was necessary to take into account the prac- tice of raising' more than one crop on the same land in a given vear. Except for Malibu, San Gabriel Mountains, and Upper Santa Ana, the hydrographio units were sub- divided into coastal and interior isoclimatic zones, in order to account for variations in consumptive use of water. Estimated unit seasonal values of consumptive use of applied irrigation water and of precipitation by various crop groups are presented in Table 89. In the determination of the probable ultimate water requirement on farm lots, unit seasonal values of water use were assumed to be the same as the unit values determined for rural residence in Tables 90 and 91. Urban and Suburban Water Use In all hydrographio units except San Diego, the estimates of present unit seasonal values of consump- tive use of water on urban and suburban land use classifications were based upon estimates of consump- tive use on the percentage of the area of each classifi- cation occupied by impervious areas, bare lands, lawns, shrubs, etc.. and upon estimates of other urban consumptive uses, such as household use, air condi- tioning, etc. It was assumed that these present unit values would remain unchanged ultimately. In the San Diego Hydrographio Unit, urban and suburban water requirements were estimated on the basis of total water delivery, and unit values of consumptive use of applied water were not estimated for individual urban and suburban land use classifications. TABLE 89 ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, SOUTH COASTAL AREA (In feet of depth) Hydrographio unit Alfalfa Pasture Orchard Walnuts Citrus and subtropical Refer- ence number Name Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total 1 2 Ventura Interior Santa Clara-Calleguas ? 1 2.5 2.1 2.4 2.0 1.1 1.1 1.1 1.1 1.3 3 . 2 3.0 3.2 3.5 3.3 2.1 2.5 2.1 2.3 2.1 1.1 1.1 1.1 1.1 1.2 3.2 3.6 3.2 3.4 3.3 1.3 1.5 1.3 1.5 1.3 1.2 1.3 1.2 2.6 2.7 2.6 2.7 1.6 1.6 1.6 1.7 1.5 1.1 1.3 1.1 1.1 1.3 2.7 2.9 2.7 2.8 2.8 1.3 1.6 1.3 1.4 1.2 0.9 0.9 0.9 1.0 1.1 2.2 2.5 2.2 2.4 3 Malibu -_____. 2.3 4__ 1.4 1.6 1 .6 1.5 1.5 1.5 1 . 6 1.4 1 .5 1.5 1.8 1.6 1.4 1.2 1.1 1.3 1.2 1.2 1.0 1.3 1.2 1.2 0.8 1.1 2.8 2.8 2.7 2.8 2.7 2.7 2.6 2.7 2.7 _'.7 2.6 2.7 5 6 L'pper Santa Ana - - _ _ Los Angeles 2 . 5 2.4 2.3 2.2 2.4 2.3 2.1 2.1 2.2 2.4 2.5 1.2 1.1 1.3 1.2 1.2 1.0 1.4 1.2 1.4 0.9 1.0 3.7 3.5 3.6 3.4 3.6 3.3 3.5 3.3 3.0 3.3 3.5 2.5 2.4 2.5 2.3 2.5 2.3 2.3 2.2 2.4 2.4 2.5 1.2 1.1 1.1 1.1 1.1 1.0 1.2 1.1 1.2 0.9 1.0 3.7 3.5 3.6 3.4 3.6 3.3 3.5 3.3 3.6 3.3 3.5 1.8 1.8 1.6 1.7 1.7 1.8 1.6 1.6 1.6 1.9 1.8 1.2 1.1 1.3 1.2 1.2 1.0 1.2 1 ..' 1.3 0.9 1.1 3.0 2.9 2.9 2.9 2.9 2.8 2.8 2.8 2.9 2.8 2.9 1.5 1.3 1.4 1.2 1.4 1.3 1.3 1.2 1.3 1.4 1.5 1.1 1.1 1.2 1.1 1.1 1.0 1.2 1.1 1.2 0.9 1.0 2.6 2.4 7 Interior . San Juan Capistrano Coastal . ... 2.6 2.3 2.5 8 Santa Margarita-San Luis Rey Coastal _ 2.3 •'.5 9 10 San Dieguito-Cottonwood Coastal . . . _ . Interior . . . San Diego Coastal Interior ......... ... 2.3 2 . 5 2.3 136 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 89— Continued ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, SOUTH COASTAL AREA (In feet of depth) Hydrographic unit Truck crops Beans Hay and grain Miscellaneous crops Refer- ence numbei Name Applied water Precipi- tation Total Applied water Precipi- tation Total Applied water Precipi- tation Total Applied water Precipi- tation Total 1 Ventura Coastal 1.0 1.2 1.0 1.1 1.0 1.2 1.3 1.3 1.2 1.2 1.4 1.3 1.2 1.2 1.3 1.4 1.4 1.1 1.0 1.1 1.0 1.1 1.0 0.8 0.9 0.9 0.9 0.7 0.8 0.8 0.9 0.8 0.7 0.7 2.1 2.2 2.1 2.1 2.1 ■> ■> Interior 2 Santa Clara-Calleguas Coastal .. 1.1 1.1 1.0 1.1 2.1 2. 2 o.r, 0.7 0.9 0.9 1.5 l.G Interior 1.1 1.0 2.1 3 Malibu . 4 San Gabriel Mountains 5 Upper Santa Ana . .. 2.1 2.2 2.1 2.1 2.1 2.0 2.1 2.1 2.1 2.1 0.7 0.7 0.7 1.0 0.9 1.0 1.7 1.6 1.7 1.3 1.3 1.2 1.3 1.3 1.4 1.2 1.4 1.2 1.4 1.5 0.8 0.9 0.9 0.8 0.8 0.6 0.8 0.6 1.1 0.6 0.6 2.1 6 Los Angeles Coastal . . 1.3 0.9 2.2 9 2 Interior 2.1 7 San Juan Capistrano Coastal . . 1 .2 1.3 1 . 2 1 .2 1 .2 1.3 1.3 0.8 0.7 0.7 0.8 0.8 0.8 0.7 0.7 2.0 2.0 1.9 2.0 2.0 2.0 2.0 2.0 2.1 Interior __ 0.4 0.5 0.4 0.3 0.2 1.2 1.0 1.1 1.2 1.4 1.6 1.5 1.5 1.5 1.6 2.1 8 Santa Margarita-San Luis Rey Coastal 2.0 Interior . 2.0 9 San Dieguito-Cottonwood Coastal . _ __ 2.0 Interior-. 2.3 10 San Diego Coastal 2.0 Interior 2.1 Present unit values of net delivery of water to ur- ban and suburban types of land use classification were based upon field surveys made in the Los An- geles and San Diego Hydrographic Units. In accord- ance with the methods described in Chapter II, total water deliveries to known areas occupied by the var- ious classifications were determined, and unit values of delivery of water were derived from these data. In the determination of ultimate unit values of delivery of water, present unit values were modified somewhat in certain of the classifications to account for trends tending to alter the present values. Table 90 presents unit seasonal values of consump- tive use of water on, and net delivery to, land use classifications in the Los Angeles Hydrographic Unit. Table 91 lists estimated net delivery of water to various classifications used in the San Diego Metro- politan Area survey. Tables 90 and 91 indicate that the present seasonal delivery of water to downtown types of commercial areas in Los Angeles is 10.2 feet of depth, and that it is 28.6 feet in San Diego. The difference is due to the fact that in the downtown type of commercial area in San Diego the development consists almost entirely of large buildings with relatively high water use, while in Los Angeles, one- and two-story buildings with a comparatively low water use represent a pro- portionately large part of the area. Weighted mean unit values of seasonal delivery and consumptive use of water applicable to gross TABLE 90 ESTIMATED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY AND CONSUMPTIVE USE OF WATER ON URBAN AND SUBURBAN LAND USE CLASSIFICATIONS, LOS ANGELES HYDROGRAPHIC UNIT (In feet of depth) Delivery Con- sumptive Land use classification Present Ultimate use of applied water Residential, single . 2.6 4.5 2.0 1.8 3.4 10.2 9.2 0.9 1.9 1.3 0.0 0.0 0.0 0.0 0.0 2.8 1 3 Residential, multiple. . 5 3 Residential, estate . 2.2 1.5 Residential, rural 1.8 8 Commercial, strip .. Commercial, downtown .. ... 4.0 11.0 8.5 1.1 1.9 1.3 0.0 0.0 0.0 0.0 0.4 1.1 Industrial, manufacturing. Schools .... 1.4 4 Dairies. 1 Livestock and poultry ranches. __ Oil fields... __ 0.6 Subdivided, not occupied 0.0 Vacant Airports no Streets and roads ... 0.0 urban and suburban water service areas within hydro- graphic units, for both present and probable ulti- mate conditions of development, are presented in Table 92. Weighted mean unit values of consumptive use of water in the San Diego Hydrographic Unit were estimated from the relationship of consumptive use and delivery in the Los Angeles Metropolitan Area. SOUTH COASTAL AREA 137 TABLE 91 ESTIMATED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY TO URBAN AND SUBURBAN LAND USE CLASSIFICATIONS, SAN DIEGO HY- DROGRAPHIC UNIT (In feet of depth) Land use classification Unit delivery 2.4 Residential, single, without lawns 2.5 3.4 Public housing, multiple story Residential, multiple Residential, rural Commercial, strip 6.2 7.4 2.2 3.7 28.6 11.8 1.8 1.8 1.1 Livestock and poultry ranches 0.6 1.1 0.0 0.0 0.0 0.0 Table 92 indicates that probable ultimate mean unit values of urban water use will be significantly larger than the corresponding present unit values. This results largely from the assumption that the percentage of the gross urban area occupied by lands not requiring water service will decrease under ulti- mate conditions of development, due to occupancy of lands now vacant. The difference between the ultimate mean unit urban delivery values for the Los Angeles Hydro- TABLE 92 ESTIMATED WEIGHTED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY AND CONSUMPTIVE USE OF WATER ON GROSS URBAN AND SUBURBAN AREAS, SOUTH COASTAL AREA (In feet of depth) Hydrographic unit Present Probable ultimate Refer- ence num- ber Name De- lh-ery Con- sump- tive use of applied water De- livery Con- sump- tive use of applied water 1 1.0 1.2 1.2 0.4 0.4 0.5 2.2 2.5 2.0 0.8 2 3 Santa Clara-Calleguas 0.8 0.8 4 _.. 5 1.9 2.0 1.4 1.9 1.0 1.8 1.9 0.7 0.6 0.8 0.7 0.6 0.6 0.6 2.4 2.8 2.1 2.1 2.1 2.0 2.5 0.8 6 0.8 7 0.8 8 9 10 Santa Margarita-San Luis Rey San Dieguito-Cottonwood 0.8 0.8 0.6 Weighted averages, South 0.8 graphic Unit and the corresponding value for the San Diego Hydrographic Unit is primarily due to the relatively smaller industrial area in the San Diego Metropolitan Area. It was assumed that future growth in San Diego will be similar to that which has taken place to the present time, and that industrial areas will continue to occupy a relatively small per- centage of the gross urban area. Use of Water in Other Water Service Areas Unit values of water use on lands requiring water service, but not included in the irrigated or urban and suburban water service areas, were derived gen- erally from measured or estimated present deliveries of water to typical areas involved, or from records and estimates of per capita use of water. Since the quantity of water involved is small, and generally the recovery of return flow is negligible, total deliv- eries were considered to be consumptively used. Unit values of water use within national forest boundaries were estimated by the United States For- est Service for both present and probable ultimate conditions of development. These estimates were gen- erally in terms of per capita use of water, and were based on actual measurements and experience. Unit values of probable ultimate water use on scattered residential, industrial, and recreational de- velopments were determined on the basis of estimated population densities varying from 4 to 40 persons per square mile, and a per capita water use of 70 gallons per day. Water use in areas above an eleva- tion of 3,000 feet was assumed to occur during the three summer months, while below an elevation of 3,000 feet, the water service was assumed throughout the year. CONSUMPTIVE USE OF WATER Consumptive use of water in water service areas of the South Coastal Area was generally determined by applying appropriate unit seasonal values of con- sumptive use of water to estimated areas occupied by crops of the various groups or to the urban and suburban classes of land use. Estimates of seasonal consumptive use of applied water and precipitation in present water service areas are given in Table 93. Table 94 presents corresponding estimates for prob- able ultimate conditions of development. These values represent the seasonal value of consumptive use of water under mean conditions of water supply and climate. In some hydrographic units of the South Coastal Area, actual present consumptive use of water is somewhat less than the optimum values from Table 93, due to existing deficiencies in water supply in portions of those hydrographic units. 138 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 93 ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF WATER ON PRESENT WATER SERVICE AREAS, SOUTH COASTAL AREA (In acre-feet) Hydrographic unit Irrigated lands Urban and sub- urban areas Un- classi- fied areas A pprox- imate total Name sump- Refer- ence number Applied water Precipi- tation tive Applied water Applied water use of applied water 1 6,400 157,000 1,400 400 299,000 355,000 7,900 31,100 29,800 31,000 3,900 116,000 1,100 300 201,000 253,000 6,000 24,900 24,100 16,500 3,200 8,800 700 42,600 250,000 1,900 3,200 2,500 24,800 100 200 200 1,400 100 100 300 9,700 166,000 2,100 600 2 Santa Clara-Cal- 3 Malibu.-. 4 San Gabriel Moun- 5 6 7 8 9 10 Upper Santa Ana- Los Angeles San Juan Capis- trano Santa Margarita- San Luis Rey San Dieguito-Cot- tonwood San Diego APPROXI- MATE TOTALS- -. 343,000 605,000 9,800 34,400 32,600 55,800 919,000 647,000 338,000 2,400 1,259,000 FACTORS OF WATER DEMAND In the planning of water conservation projects and accompanying' distribution systems, certain fac- tors in addition to consumptive use of water must be given consideration. Among these factors are nec- essary rates, times, and places of delivery of water, quality of water, losses of water, soil conditions, and other pertinent considerations. The most important of these factors in the South Coastal Area are those relating to the monthly distribution of water demands and the effciency of water utilization. These demand factors are briefly discussed in the following sections. Monthly Distribution of Water Demands Monthly demand for irrigation water may vary from little or none during the winter months to more than 15 per cent of the seasonal total during a dry summer month. The monthly distribution of seasonal water demand varies with the crop, soil type, and distance from the coast. Urban water demands are substantially higher during the summer months, but exhibit greater uniformity throughout the season than those for irrigation. Table 95 presents estimates of the average monthly distribution of seasonal water demands for urban lands and for irrigated agriculture in the South Coastal Area. The values for urban de- mands are based on delivery records of the Los Angeles Department of Water and Power during the period from 1944 through 1951. The values for irriga- tion demands are based on records of several water service agencies throughout the area, and are indica- tive of current practice. Water Service Area Efficiency Determination of seasonal water requirements in the South Coastal Area involved evaluation of the consumptive use of applied water, and also the un- avoidable and irrecoverable losses incurred in the con- veyance and utilization of the water. Water require- ments in the South Coastal Area were determined from consideration of total water application in each hydrographic unit, consumptive use of applied water, irrigation efficiency, subsequent re-use of a portion of the applied water, losses associated with conveyance of water to places of use, and the final loss by dis- charge to the ocean. The effect of irrecoverable losses upon the water requirement may be measured by the TABLE 94 PROBABLE MEAN SEASONAL CONSUMPTIVE USE OF WATER ON ULTIMATE WATER SERVICE AREAS, SOUTH COASTAL AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Approximate Refer- Name total consumptive use of applied water ence number Applied water Precipitation Applied water Applied water Applied water 1 _ Ventura __ ._ 8,500 205,000 3,700 400 563,000 80,800 121,000 25 1,000 300,000 34,900 5,000 144,000 3,000 300 352,000 54,100 75,400 201,000 212,000 18.800 200 6,400 200 16,400 73,900 17,900 500 2,701) 400 900 4,500 1,300 1,000 1,700 2,600 400 25,600 2„- Santa Clara-C'alleguas . 288,000 3 M.ilil.ii 22 200 4 San Gabriel Mountains 1,300 5 6 Upper Santa Ana _ Los Angeles. . 187,000 770,000 22,800 29,100 22,700 124,000 755,000 852,000 7 San Juan Capistrano 3,800 8,900 9,100 149,000 8 Santa Margarita-San Luis Rey . 291,000 9 San 1 lieguito-Cottonwood 334,000 in San Diego . 159,000 APPROXIMATE TOTALS 1,508,000 1 ,065,000 28,600 1,264,000 16,000 2, 877.000 SOUTH COASTAL AREA 139 TABLE 95 DISTRIBUTION OF MONTHLY WATER DEMANDS, SOUTH COASTAL AREA (In per cent of seasonal total) Month January February March April May June July August September October November December TOTALS Irrigation demand 100.0 Urban demand 6.4 6.4 7.0 8.0 9.1 9.8 10.8 10.6 9.6 8.4 7.3 6.6 100.0 water service area efficiency, denned as the ratio of consumptive use of applied water in a service area to the gross amount of water delivered in the area. Water service area efficiencies were estimated for each hydrographic unit of the South Coastal Area, after consideration of both irrigated and urban and sub- urban lands therein. Irrigation efficiency is defined as the ratio of con- sumptive use of applied water to the total amount of water applied to irrigated crops. In the South Coastal Area there are significant variations in irrigation efficiency, dependent upon crop, soil type, topographic characteristics, cost and availability of water, and local irrigation practice, Generally throughout the area, irrigation efficiencies average about 70 per cent. The relatively high efficiency is principally attributed to existing water deficiencies and the high cost of water supplies in some portions of the area. Compari- son of the total pumpage of ground water for irrigated lands on the coastal plain of Ventura County with the estimated total consumptive use of applied water on these lands, for the period from 1944-45 through 1951-52, provided further substantiation for the de- rived values for average irrigation efficiency. Table 96 presents the estimated water service area efficiencies under present and probable ultimate condi- tions of development. Predictions of ultimate water service area efficiencies are obviously subject to ma- terial change, and such efficiencies will be dependent in great part on ultimate plans for water service, and the extent to which return flow from irrigated lands and urban areas can be regulated and re-used. WATER REQUIREMENTS Water requirements, as the term is used in this bulletin, refer to the amounts of water needed to provide for all beneficial uses of water and for any irrecoverable losses incidental to such uses. Certain requirements for water which are basically noncon- sumptive in nature are discussed briefly in the follow- ing section in general terms. Following this, water requirements of a consumptive nature are evaluated for both present and probable ultimate conditions of development. Requirements of a Nonconsumptive Nature The principal nonconsumptive water requirements of the South Coastal Area are those pertaining to preservation and propagation of fish and wildlife, flood control, repulsion of sea water from ground water basins, and salt balance in irrigated areas. This bulletin does not evaluate the quantities of water involved in satisfying these requirements, since the quantities in many instances are dependent upon the evolution of definite plans for development of water resources. Their consideration herein is limited to discussion of their implications as related to planning for future water resource development. TABLE 96 ESTIMATED WEIGHTED MEAN WATER SERVICE AREA EFFICIENCY WITHIN HYDROGRAPHIC UNITS, SOUTH COASTAL AREA (In per cent) Hydrographic unit Present Probable ultimate Refer- ence number Name Irrigated Urban and suburban Weighted mean Ii i in;itt'i] Urban and suburban Weighted mean 1 2 3 4 5 6 7 8 9 10 Ventura Santa Clara-Calleguas Malibu San Gabriel Mountains Upper Santa Ana Los Angeles San Juan Capistrano Santa Margarita-San Luis Rey San Dieguito-Cottonwood San Diego Weighted averages, South Coastal Area 90 95 90 100 85 75 95 80 05 90 55 50 50 90 35 50 45 55 30 40 75 90 70 95 55 70 90 75 40 65 100 80 80 95 80 80 80 80 65 85 45 50 65 65 55 35 70 90 30 30 40 70 50 75 55 75 30 35 50 140 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Navigation, although a factor in the water prob- ments do not decrease supplies available to meet re- lems in some other portions of the State, is not a con- quirements of a consumptive nature. This does not, sideration in the water resource development of the however, signify that fisheries will not benefit by South Coastal Area. Similarly, there is but negligible future water development, particularly by importa- generation of hydroelectric power in the South Coastal tion of water from outside sources. Reservoirs created Area. The present installed power capacity of hydro- to impound water will provide additional habitat for electric power plants utilizing local water supplies is game fish populations. Water released in stream beds less than 15,000 kilowatts. Additionally, hydroelectric for downstream requirements will, if the water is power plants in the South Coastal Area, operated in drawn from the deeper parts of the reservoir, pro- conjunction with the Los Angeles Aqueduct from the vide conditions suitable for the development of trout Owens River, have an installed power capacity of fisheries. It is necessary only to provide minimum pool about 100,000 kilowatts. The limited and erratic oc- elevations in the reservoirs, and assure public access currence of runoff in streams of the South Coastal to the created waters, to realize fisheries benefits from Area makes it improbable that there will be any sig- water development in the South Coastal Area, nificant future increase in hydroelectric power gen- Water requirements for game species in this area eration. are estimated to be less than 0.5 acre-foot per day. ■n- i. -i wi irr -n i j- i • -l! Development of water for this purpose has consisted Fish and Wildlife. Fresh-water fishing m the „ -, . , ,, , „ ,, ,,. ^ ^ ,,,■*« ~ ,, r , , , , . , , , , of the installation of gallinaceous guzzlers (self- South Coastal Area is characterized bv many anglers ... . , . . ., „ \ , -, -,. .,-,/. i ■ mi * xi j. ' sustaining watering devices) primarilv for upland and limited fishing waters. The waters that are pres- . r. . -T ■, ' » , n ,.,. -, , ,, . ., game species, Future water development for paine ent, however, are utilized to their maximum capacity. . . , , , , . ., ,. & ' ,. „ ,, „ ,, , , , i , species is expected to be along similar lines. Practically all of the headwater streams, lakes, and reservoirs are planted regularly with catchable trout Flood Control. Many projects designed to protect by the California Department of Fish and Game. It property adjacent to stream channels from damage is in this area that the catchable trout program has by flood flows have been constructed in the densely reached its greatest development, with angling pres- developed portions of the South Coastal Area, and sures so great that the majority of the planted trout particularly in the Los Angeles Metropolitan Area, are caught. During the 1954 trout angling season Large reservoirs, including Lopez, Sepulveda, and approximately 1,500,000 eatchable-size trout were Hansen on the Los Angeles River and tributaries; planted here, and it is estimated that at least two- San Gabriel No. 1, San Gabriel No. 2, Santa Fe. and thirds of them were caught. Whittier Narrows on the San Gabriel River and trib- Reservoirs located at low and moderate elevations utaries; and San Antonio, Prado, and others on the in the South Coastal Area support excellent popula- Santa Ana River and tributaries, have been, or are tions of warm-water game fish. Favorable climatic being constructed to impound flood flows for later re- conditions and heavy angling pressures contribute to lease. Many miles of channel in the Los Angeles River high yields from these reservoirs. Angling catch esti- and San Gabriel River systems have been lined with mates for 1953, based on post card surveys by the impervious materials. Levees have been constructed Department of Fish and Game, show the following along the San Gabriel and Santa Ana Rivers, and to catches of warm-water fish in this region: a lesser degree along the Ventura and San Diego Number ca u ght in Per cent of Rivers. Many debris basins have been constructed, Species South Coastal Area State total principally on tributaries of the Los Angeles and San Black bass !?*5'299 2 2 Gabriel Rivers. Extensive storm drain systems have Catfish 450,000 6 , x x -, , «. „ „ -, » Oappie _ 1,430,000 40 been constructed to carry off valley floor runoff from Sunfish 1,760,000 28 intensively urbanized areas. The municipal water supply reservoirs owned by the The Cor P s of Engineers, United States Army, in City of San Diego are examples of those supporting cooperation with local agencies, is engaged in a con- successful warm-water fisheries in this area. Numer- tinuing program of planning and construction for ous farm ponds also provide warm-water fishing. flood protection in the South Coastal Area, In 1952 Several streams in the South Coastal Area, such as tlie people of Los Angeles County provided $179,000,- the Ventura and Santa Clara Rivers, and, to a lesser 00 ° for expenditure by the Los Angeles County Flood degree, Malibu and San Juan Creeks, support minor Control District in the construction of additional runs of steelhead trout when sufficient flow is avail- storm drain facilities for protection of urban areas, able in the streams. Sufficient water is seldom avail- Alteration of the natural regimen of streams and able, however, and this fishery is only of minor value. channels in the South Coastal Area has significantly It is considered doubtful that the limited water re- affected the recharge of ground water basins. The sources of the South Coastal Area can meet addi- operation of reservoirs for flood control purposes tional water requirements for the preservation and involves the temporary storage of flood flows and enhancement of fish life, except when such require- subsequent rapid release. Many of the channels and SOUTH COASTAL AREA 141 outflow areas from which water previously perco- lated have been paved or otherwise altered so as to expedite discharge of water to the ocean. Lands which formerly were flooded at frequent intervals have been improved for urban, industrial, and agricultural uses and provided with drains for rapid disposal of flood waters. Conservation of a portion of the flood waters which would otherwise be wasted is accomplished by construction and operation of spreading grounds for ponding of flood control reservoir releases. The Los Angeles County Flood Control District has operated spreading grounds for several years, and is now con- structing- additional water-spreading areas concur- rently with the construction of flood protection works. Subsurface Outflow From Ground Water Basins to Ocean. In the South Coastal Area several confined ground water basins adjacent to the coast have been experiencing deterioration in water quality by intru- sion of sea water. This intrusion may be prevented by maintaining pressure levels in these basins at ele- vations such that subsurface outflow of fresh water will occur during periods of little or no pumping draft. Determination of the quantities of water re- quired to prevent sea-water intrusion will be depend- ent upon specific plans of development and pumping draft. However, it appears that a substantial amount of water will be unavoidably lost by such outflow, particularly from the coastal plains of Ventura, Los Angeles, and Orange Counties. Studies conducted by the Division of Water Resources in Ventura County indicate that if pumpage from the presently over- drawn ground water basins underlying the coastal plain were limited to the safe yield of the basins, sub- surface outflow to the ocean from these basins would be about 20,000 acre-feet per season. The Los Angeles County Flood Control District is currently conducting a field experimental project in the Manhattan Beach-Hermosa Beach area to investi- gate the hydraulic feasibility of creating a pressure ridge in confined aquifers by means of injection wells, and the effectiveness of such a ridge in preventing sea-water intrusion. The project was initially financed from a state appropriation in the amount of $750,000, but since July 11, 1954, funds for this project have been furnished from a Flood Control District ad valorem zone tax. Salt Balance. Local irrigation water supplies are, for the most part, obtained by pumping from ground water storage. The estimates of requirements for water of a consumptive nature, which are subsequently set forth, are predicated upon utilization of ground water storage capacity so as to facilitate the re-use of local and imported water applied to lands in ex- cess of consumptive use. Natural replenishment of many ground water basins in the South Coastal Area is derived from surface drainage from tributary watersheds, and by subsurface outflow from upstream basins. The mineral quality of the ground water con- tained in these basins must be protected from exces- sive deterioration in order to maintain the utility of the storage capacity. This will require sufficient drain- age from the basins to remove a quantity of dissolved salts equivalent to the amount of salt input to the basins. Quantitative estimates of the amount of water required for this purpose will necessarily depend upon the formulation of specific plans for future de- velopment in each instance. Requirements of a Consumptive Nature Requirements for water represent the quantities of water, other than precipitation, which must be supplied to provide for beneficial consumptive use of water on irrigated lands, urban and suburban areas, and other water service areas, and to provide for irrecoverable losses incidental to such use. Present and probable ultimate water requirements in the South Coastal Area were determined by use of the previously derived estimates of total water applica- tion and consumptive use of applied water, giving consideration to the possible re-use of a portion of the applied water and to losses incurred in convey- ance to the place of use. In general, in irrigation water service areas over- lying or immediately adjacent to major free ground water basins, it was assumed that re-use of all water applied in excess of consumptive use could be accom- plished. The water requirement for such areas was therefore taken as equal to the consumptive use of applied water plus any irrecoverable conveyance loss. In those irrigation water service areas adjacent to the coast or overlying confined aquifers, it was as- sumed that no re-use of applied water could be effected in excess of consumptive use. The water requirement in these cases was assumed to be equal to the total water applied plus irrecoverable conveyance losses. In inland areas overlying nonwater-bearing forma- tions, or ground water basins of relatively small stor- age capacity in comparison with the potential water- using development, studies were made in order to estimate the portion of return flow from applied water that would be susceptible of re-use, and which would be irrecoverably lost. For such areas the water requirement was taken as the summation of consump- tive use of applied water and irrecoverable losses Urban and suburban water requirements were evaluated in the same general manner as those for irrigated lands, except that consideration was given to the effect on requirements in urban areas overlying free ground water basins of construction of sewerage facilities with ocean discharge. The present water re- quirement for these urban areas was estimated as the sum of consumptive use of applied water, present export to the ocean of sewage, and irrecoverable con- 142 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA veyance loss. The probable ultimate urban require- ment in inland areas overlying- free ground water basins was assumed to be the sum of consumptive use of applied water on the portion of the area without ocean discharge of sewage, total applied water on the portion of the area with such disposal, and irrecover- able conveyance losses. It was assumed that in the Los Angeles Hydrographic Unit, 85 per cent, and in the Santa Ana Hydrographic Unit. 20 per cent of the probable ultimate urban and suburban area over- lying free ground water would use ocean disposal of sewage. No consideration was given to reclamation and re- use of sewage which would otherwise be discharged to the ocean. Large quantities of water could be salvaged in this manner. Experimental projects to determine the feasibility of reclamation of sewage are presently being conducted in portions of the Los An- geles Hydrographic Unit, Sufficient data are not presently available to evaluate quantitatively the effect of such sewage reclamation, and exploitation of this potential source of water supply is considered as development of new water in this bulletin. Table 97 presents estimated present and probable ultimate water requirements for each hydrographic unit of the South Coastal Area. Ultimate urban and suburban water requirements in the Los Angeles and San Diego Metropolitan Areas were also independently estimated, on the basis of forecast ultimate population. This procedure in- volved determination of the areas ultimately sus- ceptible of urban and suburban development, the ulti- mate population densities in these areas, and the ultimate per capita water requirement, In the Los Angeles Hydrographic Unit the bound- ary of the area ultimately to be devoted to urban and suburban land uses was determined with reference to topographic suitability and residual agricultural development. The boundary as determined included an area of about 905,000 acres. The ultimate popula- tion density in this area was estimated to be about 13.6 persons per acre, based upon a detailed study of approximately the northern half of the Los Angeles County portion of the metropolitan area. This indi- cated an ultimate population for the entire hydro- graphic unit of about 12,300,000. The present use of Avater, based on available data in portions of the ulti- mate area, indicated that the ultimate per capita water requirement would be about 190 gallons per day. The ultimate urban and suburban seasonal water requirement was, on this basis, estimated to be about 2,600,000 acre-feet. The San Diego Hydrographic Unit was subdivided, for purposes of analysis, into areas corresponding to census tracts or enumeration districts. Within each subdivision two topographical zones were delineated, one assumed to be ultimately fully developed and the other, of intermediate topography, assumed to be ultimately deA'eloped to one-half maximum density. The effective habitable area for each subdivision was assumed to be equivalent to the total area of the first zone plus one-half the area of the latter zone. Deduc- tions from the effective habitable area were made for ultimate industrial areas and residual agriculture, prior to applying estimated population densities. Ulti- mate population densities applicable to the urban area, exclusive of industry, were estimated for each subdivision. The result of this analysis indicated that the total ultimate urban area (exclusive of industry) would be about 150.000 acres, and that the ultimate population would be about 1,990,000. Ultimate per capita water use in this hydrographic unit, including industrial use of water, was estimated to be about 160 gallons per day. The ultimate urban and suburban seasonal water requirement was, therefore, estimated to be about 360,000 acre-feet, TABLE 97 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL REQUIREMENTS FOR WATER, SOUTH COASTAL AREA (In acre-feet) Hydrographic unit Reference number Name Irrigated lands Present Probable ultimate Farm lots Probable ultimate Urban and suburban areas Present Probable ultimate Other water service areas Present Probable ultimate Approximate totals Present Probable ultimate 1 2 3 4 5 6 7 8 9 10 Ventura Santa Clara-Calleguas Malibu San Gabriel Mountains Upper Santa Ana Los Angeles San Juan Capistrano Santa Margarita-San Luis Rey__ San Dieguito-Cottonwood San Diego APPROXIMATE TOTALS 7,100 165,000 1,600 800 299,000 418,000 10,500 32,800 37,300 47,700 8,500 256,000 4,600 9,000 5,800 17,600 1,400 29,800 164,000 35,800 100 200 593,000 101,000 151,000 313,000 375,000 53,700 6,000 15,000 15.000 47,300 716,000 3,800 7,100 4,500 81,700 267,000 2,568,000 57,000 58,200 41,300 414,000 200 1,400 100 100 300 500 2,700 400 1,000 4,500 1,300 1,000 1,700 2,600 400 13,000 183,000 3,000 1,000 348,000 1,134,000 14,300 40,000 42,100 129,000 38,800 432,000 40,800 1,000 864,000 2,670,000 215,000 388,000 434,000 468,000 1,020,000 1,856,000 45,000 885,000 3,635,000 2,400 16,100 1,907,000 5,552,000 SOUTH COASTAL AREA 143 Supplemental Requirements The supplemental water requirement, as the term is used in this bulletin, refers to the quantity of water, in addition to safe yield of the present water supply development, which must be made available to fully satisfy the present or probable ultimate water re- quirement. The present supplemental requirement represents the difference between the present water requirement and the sum of presently developed safe yield of local supplies and present import of water. The difference between estimated present and prob- able ultimate Avater requirements for each hydro- graphic unit, plus the present supplemental require- ment, was taken as the measure of the probable ultimate supplemental water requirement. The existence of a present supplemental require- ment is indicative of one or more of several condi- tions. In certain portions of the South Coastal Area, irrigated crops are being supplied with amounts of water which are insufficient to provide for optimum consumptive use, with resultant decrease in crop yield and damage to plants. In San Diego County surface reservoirs have been operated in excess of safe yield, with the result that in the latter years of the recent drought period many of the reservoirs were dry. Except for the timely importation of Colorado River water, the San Diego Hydrographic Unit would be experiencing a water deficiency aggregating approxi- mately 50 per cent of the present requirement for the unit. In the Santa Clara-Calleguas, Upper Santa Ana, and Los Angeles Hydrographic Units, and to a lesser extent in other units, extractions from ground water storage have exceeded safe yields of the underground reservoirs, resulting in appreciable overdrafts on existing supplies. Indications of possible ground water overdraft in the South Coastal Area include perennial lowering of ground water levels, sea-water intrusion, and dewatering of the ground water basins with limited storage capacity to the extent that overlying users are deprived of water supplies during drought periods. Safe Yield of Local Water Supplies With Present Development. In connection with studies to deter- mine values of presently developed safe seasonal local yield, use was made of data appearing in recent publi- cations of the State Water Resources Board, the Division of Water Resources, and other organizations. Use was also made of unpublished data compiled in conjunction with the investigations currently being conducted by the Division of Water Resources. Values of safe yield presented in this bulletin in many instances must be considered as approximations, and only indicative of the general order of magnitude. In those areas where detailed data were not available and where water shortages are not presently appar- ent, safe yield of the present water supply develop- ment was assumed to be equal to the estimated present water requirement. Estimates of presently developed safe seasonal local yield in hydrographic units of the South Coastal Area are presented in Table 98. TABLE 98 ESTIMATED PRESENTLY DEVELOPED SAFE SEASONAL YIELD OF LOCAL WATER SUPPLIES, SOUTH COASTAL AREA (In acre-feet) Hydrographic unit Refer- ence number Name Safe yield 1 2 3 4 5—. . Ventura Malibu San Gabriel Mountains 9,000 115,000 3,000 1,000 266,000 6 7 8 9 10 Los Angeles San Juan Capistrano Santa Margarita-San Luis Rey San Dieguito-Cottonwood San Diego TOTAL 509,000 13,000 29,000 34,000 62,000 1,041,000 Imported Water Supplies. The City of Los An- geles imports water from the Mono Basin and Owens River watersheds in the Lahontan Area through the Los Angeles Aqueduct. Such import of water supple- ments local supplies for only a portion the Los Angeles Metropolitan Area, as the City of Los An- geles restricts the delivery to the incorporated area of the city. During the 1949-50 season, the imported water supply was about 305,000 acre-feet. The capacity of the aqueduct is estimated by the Los Angeles De- partment of Water and Power to be about 320,000 acre-feet annually. The Metropolitan Water District of Southern Cali- fornia imports supplemental water from Lake Havasu on the Colorado River through an aqueduct terminat- ing at Lake Mathews in Riverside County. Cities and water districts forming the district are shown on Plate 13. Water is distributed by the Metropolitan Water District to all member cities and water districts except those in San Diego County. Colorado River water is supplied to San Diego County through an aqueduct which joins the the Colorado River Aque- duct near the City of San Jacinto and terminates in San Vicente Reservoir. From that point the water is distributed to member agencies by the San Diego County Water Authority. During the 1949-50 season about 166,000 acre-feet of water were distributed to member cities and water districts, and to the San Diego County Water Authority, by the Metropolitan Water District. This import had increased to 246,000 acre-feet during the 1953-54 season. 144 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Table 99 presents estimates of water supplies im- ported to the South Coastal Area during the 1949-50 season. In accordance with the 1931 Seven-Party Water Agreement, the Metropolitan Water District of South- ern California, including the San Diego County Water Authority, is allotted 1,212,000 acre-feet per year of California 's rights to water from the Colorado River. It has been estimated that due to conveyance losses the amount actually available for consumptive use in the South Coastal Area will be about 1,150,000 acre-feet per season. Thus a quantity of about 975,000 acre-feet of water from this source, over and above actual 1949-50 import, remains available to the area to assist in meeting the estimated ultimate water re- quirements. This amount of water, distributed among the areas requiring a present supply of supplemental water, would be more than adequate to eliminate the estimated present deficiencies. Supplemental Water Requirements. Present and probable ultimate supplemental water requirements in the South Coastal Area were determined as the difference between water requirements, as presented in Table 97, and the sum of presently developed safe TABLE 99 ESTIMATED PRESENT SEASONAL IMPORT, SOUTH COASTAL AREA (In acre-feet) Hydrographic unit Refer- ence number Name 1949-50 1 2 3 Santa Clara-Calleguas - Malibu. 4 San Gabriel Mountains 1,000 6 399,000 7 2 000 8 9 10 Santa Margarita-San Luis Rey San Dieguito-Cottonwood . 3,000 66,000 TOTAL 471,000 local yield and present import, as presented in Tables 98 and 99. Estimated supplemental water require- ments for each hydrographic unit of the South Coastal Area are given in Table 100. In some cases the in- dicated supplemental water requirement for a given hydrographic unit is less than the sum of the supple- mental requirements for small subdivisions of the unit, due to localized ground water overdrafts of re- latively small magnitude. These local overdrafts could be eliminated with modification of the pattern of dis- tribution of available water supplies within the unit. TABLE 100 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL WATER REQUIREMENTS, SOUTH COASTAL AREA (In acre-feet) Hydrographic unit Present Probable ultimate Reference number Name 1 4,000 H8.000 '9,800 9 317 000 3 Malibu.-- _ ._ -. _ _ 37,800 4 81,000 2211,000 5 597,000 6 1,7(12,000 7 '00,000 8 9 10 Santa Margarita-San Luis Rey_- San Dieguito-Cottonwood 8,000 8,000 356,000 400,000 340,000 APPROXIMATE TOTALS 395,000 4,040,000 In order to satisfy estimated ultimate water re- quirements, about 4,040,000 acre-feet of water per season will be necessary, in addition to the presently available supplies. This requirement can only be met by further conservation of local supplies and by addi- tional importation of water from sources of supply outside the South Coastal Area. About 975,000 acre- feet of the indicated ultimate seasonal supplemental requirement will be met when water supplies from the Colorado River available under existing rights are fully utilized. CHAPTER VII CENTRAL VALLEY AREA The Central Valley Area comprises all of the stream basins tributary to the Sacramento and San Joaquin Rivers. It occupies about one-third of the total area of California, and contains sixty per cent of the State's irrigable land. This large area includes lands making up the westerly drainage of the Sierra Nevada and the Cascade Range, the easterly drainage of the Coast Range, and the floor of the great Central Val- ley between latitudes 35° and 42° N. It is approxi- mately 500 miles in length and 120 miles in width. The Central Valley Area is designated Area 5 on Plate 8, and includes all or part of 39 of the State's 58 counties. Among the principal incorporated cities are Redding, Chico, Marysville, Sacramento, Stockton, Fresno, Modesto, Merced, Tulare, and Bakersfield. In order to facilitate the present study, the Central Valley Area was: subdivided into three principal basins : the Sacramento River Basin, where there is a surplus of water with only localized areas of de- ficiency ; the San Joaquin River Basin, where for the most part the water supply balances the requirements under present conditions of development ; and the Tulare Lake Basin, where the local water supply is insufficient to meet present requirements. Each of the principal basins was further subdivided into hydrographic units, the boundaries of which are for the most part coincident with watershed divides of the tributary streams, or along water service area boundaries. The hydrographic units were generally segregated into two types, mountain and valley. Each mountain unit consists of the total drainage area of one or more tributary streams above the foothill line. There is usually a A'alley unit associated with each mountain unit. The mountain units were named with reference to streams in the tributary area, and names of the valley units correspond to principal towns or to geographical locations. Table 101 lists the 63 hydro- graphic units and their areas, and Table 102 presents the areas of counties, or portions of counties, included within the Central Valley Area. The climate of the valley floor of the great Central Valley is characterized by hot summers and mild winters, light precipitation decreasing from north to south, and a summer and autumn period of nearly unbroken sunshine. The valley areas are free from frost during the normal growing season, from seven to eight months in length. Mean seasonal depth of precipitation at Red Bluff, at the northern end of the Central Valley floor, is approximately 20.3 inches, while at Bakersfield at the southerly extremity of the valley it is about 6 inches. At Modesto, approximately midway of the length of the valley, the mean seasonal precipitation depth is approximately 11 inches. Pre- cipitation is extremely variable from year to year. At Sacramento, where an unbroken record has been maintained since 1849 and the average seasonal depth of rainfall is 18.08 inches, the maximum quantity recorded in any one season was 36.35 inches, and the minimum was 4.71 inches. Over 90 per cent of the rainfall in a typical year at Sacramento occurs dur- ing the six months from November through April, and only infrequent scattered showers occur during sum- mer and fall. The bordering mountains to the north and east of the Central Valley floor rise rapidly from the foothill line to an elevation of about 5,000 feet, above which a generally Alpine climate prevails, characterized by short summers, cold winters, and a frost-free period of only three months. The Cascade Range and the Sierra Nevada receive the greatest precipitation, with slightly less falling on the northern Coast Range. At elevations above 5,000 feet nearly all winter precipi- tation occurs as snow. Depth of snowfall in the Sierra Nevada is among the greatest experienced in the United States. Norden, at Donner Summit, which is a fairly representative station at an elevation of 6,871 feet, has a mean seasonal snowfall depth slightly greater than 400 inches, having a water content of approximately 50 inches. The snow accumulates dur- ing the winter and spring months, gradually melting so as to maintain stream flow into the warmer months of the summer. It is estimated that mean seasonal natural runoff of streams in the Central Valley Area is about 33,- 640,000 acre-feet, about 48 per cent of that for the entire State. Approximately two-thirds of the runoff is provided by the Sacramento River and its tribu- taries, and the remainder by streams of the San Joa- quin River and Tulare Lake Basins. Flow in streams of the Central Valley Area is dependent upon the extent of the drainage basins and upon the quantity and distribution of seasonal precipitation. Substan- tial winter rainfall in the Coast Range and the lower foothills of the Sierra Nevada causes immediate stream runoff. In the higher mountains the winter precipitation, which occurs as snow, usually remains on the ground until warmer temperatures in the spring and summer months induce melting of the snowpack. In general, the greatest volume of stream flow occurs in the spring and early summer, diminish- (145) Mt. Shasta Courtesy Siafe Division of Highways CENTRAL VALLEY AREA 147 TABLE 101 AREAS OF HYDROGRAPHIC UNITS, CENTRAL VALLEY AREA Hydrographic unit Arli'.s Hydrographic unit Reference number Name Reference number Name Acres Sacramento River Basin Mountain Units 264,000 3,440.000 438,000 396,000 815,000 819,000 536,000 529,000 630,000 204,000 267,000 2,395,000 1,102,000 732,000 1,313,000 405,000 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 :»i 53 54 55 56 57 58 59 60 61 62 63 Valley Units 701,000 1 1,161,000 2 Pit River - - - - - - - Earlimart ........ Visalia. _ ......... . 434,000 3 McCloud River . 469,000 4 Sacramento River above Shasta Dam West Side, Shasta Dam to Cottonwood Creek East Side, Cow Creek to Paynes Creek Red Bluff to Thomes Creek... . _ 1,125,000 5 256,000 6 7 Subtotal, Vallev Units . . . . 4,146,000 8 9 APPROXIMATE TOTAL, TULARE LAKE BASIN San Joaquin River Basin Mountain L'nits Mount Diablo.. 10 9,552.000 11 12 13 . 14 15 16 Putah Creek 102,000 Altamont to San Luis Creek . West Side, Los Banos Creek to A venal Creek- 483,000 863,000 14,280,000 37,800 129,000 136,000 145,000 111,000 126,000 579,000 341,000 81,900 217,000 201,000 307,000 217,000 197,000 Valley Units 1,117,000 417,000 17 944,000 18 1,032,000 19 Stanislaus River 705,000 20 734,000 21 489,000 22 Subtotal, Mountain Units ... Valley LTnits 23... 6,886,000 24 25 26 27 28 94,400 29.. Delta-Mendota. 74,500 30 Yolo 793,000 484,000 2,826,000 523,000 APPROXIMATE TOTAL, SACRA- MENTO RIVER BASIN Tulare Lake Basin Mountain LJnits 413,000 452,000 17,110,000 306,000 2,837,000 466,000 611,000 1,186,000 86,100 254,000 574,000 272,000 481,000 Subtotal, Valley Units 31 4,501.000 32 33 Kern River and Tehachapi Mountains APPROXIMATE TOTAL, SAN JOA- QUIN RIVER BASIN 34 11.390,000 35 APPROXIMATE TOTAL, CENTRAL VALLEY AREA.. 5,406,000 38,050,000 nig in amount to little or no flow during the flnal quarter of the season. Records of stream flow for the American River, which is generally representative of streams of the Sierra Nevada, show that over 65 per cent of the seasonal runoff occurs during- the four-month period from March through June, and 93 per cent during the period from December through June. Total seasonal runoff varies from year to year in the same general pattern as precipitation. A 43-year record of flow in the American River at Fair Oaks shows that the seasonal runoff has varied from a low of 20 per cent of the average seasonal runoff in 1923- 24, to a high of 216 per cent in 1906-07. As shown on Plate 4, a total of 29 valley fill areas, which may or may not contain usable ground water, has been identified in the Central Valley Area, of which those of the Sacramento River, San Joaquin River, and Tulare Lake Basins are by far the most im- portant, both in size and in the extent to which they have been developed. The estimated gross subsurface storage capacity of the Sacramento River Basin is esti- mated to be nearly 33,700,000 acre-feet in the depth zone between 20 and 200 feet. Very little of this stor- age capacity is presently utilized. About 1,000,000 acre-feet of water is pumped from ground water stor- age during the average season, which water consti- tutes about 25 per cent of the amount consumptively used in the Sacramento River Basin in the average season under present conditions of development. 148 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 102 AREAS OF COUNTIES WITHIN BOUND- ARIES OF CENTRAL VALLEY AREA County Acres Alameda 52,500 161.000 383,000 1,072,000 665,000 740,000 180,000 999,000 3,843,000 792,000 3,598,000 893,000 660,000 911,000 2,600 1,378,000 934,000 1,270,000 1,513,000 220,000 518 000 Alpine ... Amador Butte . .. Calaveras . . _ Colusa Contra Costa . El Dorado Fresno Glenn. Kern . Kings . .. _. Lake... .. Lassen. Los Angeles . Madera- . Mariposa Merced . Modoc Napa Nevada Placer 799 000 Plumas 1,670,000 638 000 Sacramento San Benito _ _ 205 000 San Joaquin 911 000 San Luis Obispo 106 000 Shasta 2,468,000 477 000 Sierra Siskiyou. 698 000 Solano . . 342 000 Stanislaus . . 973 000 Sutter 390 000 Tehama . 1 910 000 Tulare 3 102 000 Tuolumne 1 471 000 Ventura 30 000 Yolo 662,000 412 000 Yuba APPROXIMATE TOTAL 38,050,000 The ground water basins of the San Joaquin River Basin and the Tulare Lake Basin, with estimated gross subsurface storage capacities in the depth zone between 20 and 200 feet of about 47,500,000 acre-feet and 51,400,000 acre-feet, respectively, provide sea- sonal and cyclic storage to regulate the water supplies of those basins. Ground waters on the east side of the Tulare Lake Basin have been developed to such an extent that in localized areas their rate of use on overlying lands exceeds the rate of ground water replenishment from stream flow and return drainage, resulting in overdrafts in local sub-basins. The local overdrafts are now being replenished to some extent by water from the Friant-Kern Canal. In the San Joaquin River Basin, the eastern por- tion of the ground water basin south of the Sacra- mento-San Joaquin Delta is extensively utilized to provide a partial water supply, used in conjunction with surface diversions. Except in localized areas, the use of water from this portion of the basin does not exceed replenishment. Since about 1942 the western side of the San Joaquin Valley has experienced a phenomenal expansion in agricultural development, which has caused greatly increased demand on the ground water in storage. This demand far exceeds the replenishment. During a recent 5-year period, average ground water levels in the western side of the San Joaquin River Basin dropped at a rate of approxi- mately 8 feet per year in the northern section, and 21 feet per year in the southern section. It is antici- pated that ground water will continue to be utilized in this area in the future, but that an increasing proportion of the requirement for water will neces- sarily be met by imported surface water supplies. During recent years the Central Valley Area has led all other major areas of the State in growth of population on a percentage basis. The expanding agricultural economy and related industrial growth brought an increase of population from 400,000 in 1900 to 1,900,000 in 1950, or some 375 per cent. Nearly all urban centers have grown correspondingly in size and importance, with growth in the surrounding suburban areas being particularly noticeable. Table 103 illustrates the increase in population of 14 of the principal urban communities and their associated suburbs from 1940 to 1950. It may be noted that the suburban populations of most of the cities have nearly doubled in the 10-year period, while those of Sacra- mento and Stockton have tripled, and that of Modesto has quadrupled. TABLE 103 POPULATION OF PRINCIPAL URBAN CENTERS, CENTRAL VALLEY AREA 1940 1950 City Within city limits In suburbs Total Within city limits In suburbs Total Sacramento Fresno 106,000 60,700 54,700 29,200 16,400 11,600 10,100 8,900 6,300 9,300 8,100 8,200 11.100 8,200 22,100 22,100 14,200 23,100 5,700 6,000 3,300 6,600 5,200 3,100 5,800 2,100 1,200 2,000 128.000 82,800 68,900 52,300 22,100 17,600 13,400 15,500 11,500 12,400 13,900 10.300 12,300 10.200 138,000 91,700 70,800 34,800 17,400 15.700 15,300 11,800 6,900 12,300 10,300 12,400 13.800 10,000 74,200 38,900 42,000 66,900 25,000 12,000 8,100 11,600 12,300 6,500 7.500 4,300 1,900 5,500 212,000 131,000 1 13,000 102,000 42,400 27,700 23,400 23,400 19,200 18,800 17,800 16,700 15,700 15,500 Stockton Bakersfield Modesto . . Marysville-Yuba City Merced. . Visalia. . Porterville _ _ Chico Redding. Tulare .. Lodi Hanford Agriculture, principally based on irrigation, is the major economic activity of the Central Valley Area, while the industry associated with agriculture pro- vides a substantial portion of the income. Lands devoted to irrigated agriculture have increased con- tinuously since the decade following 1850, when crops were first irrigated. By 1889, the first year in which the United States Census included data on irrigated agriculture, it was reported that approximately 635,- 000 acres were irrigated in the Central Valley Area. CENTRAL VALLEY AREA 149 At present about 4,750,000 acres, or approximately 57 per cent of the presently cultivated land in the area, are irrigated annually. The valley floor of the Central Valley is the largest and most important agricultural region of the State, producing a large variety of crops, while in the surrounding foothills are found im- portant fruit-growing and stock-raising regions. Prior to 1849, there was little activity in the Cen- tral Valley Area, the large ranchos being either un- developed or devoted almost exclusively to stock raising. Captain John Sutter's New Helvetia, in the general area of present-day Sacramento, was the most highly developed of the ranchos, although the only field crop produced was dry-farmed wheat. The mining boom of 1849 and 1850 gave impetus to agri- culture, the demand for agricultural produce and livestock increasing in direct ratio to the growth in population. Dry-farming methods provided much of the necessary grains and hay for a number of years, although irrigation was utilized for truck crops, and to some extent for alfalfa and pasture. The first developments providing water to the irri- gable lands of the Central Valley were simple earth ditches, conveying the summer flows of streams onto the adjacent lands. Later, as the mining ditches were abandoned, they were also utilized to serve lands far- ther removed from the flowing streams. One of the first irrigation diversions in the valley was a ditch constructed by James Moore in 1856, which delivered a flow of water at the rate of 2| second-feet from Cache Creek to a tract of land in Yolo County. Serious interest in irrigated farming did not develop until 1864, which was a year of severe drought. Individual efforts dominated the first attempts to divert water onto the land, followed by the construction of irri- gation canals for joint use through cooperative efforts by groups of farmers. As the population and the num- ber of farms increased and the requirements for water grew, costly and complicated irrigation systems were built to supply the water necessary for successful agricultural developments. Stock companies were formed, and large amounts of capital were invested in irrigation enterprises. Nearly all of the summer flow of the streams was appropriated for use, and the necessity for storage of winter flood waters became evident. In 1887 the Legislature passed the Wright Act, which was the forerunner of the present laws govern- ing irrigation districts. This act and subsequent amendments provided the legal framework for the development of major irrigation water supply systems, as are now exemplified by many large and successful irrigation districts. The majority of present water storage developments in the Central Valley Area have been constructed in the Sierra Nevada, although two reservoirs, East Park and Stony Gorge, are located on Stony Creek in the Coast Range. Shasta Reservoir on the Sacramento River, the key structure in the Central Valley Project, is another exception, as it is located in the Cascade Range. Two of the major structures in the Sierra Nevada were built primarily to provide urban water supplies for the San Francisco Bay Area. Hetch Hetchy Reservoir on the Tuolumne River serves the City of San Francisco, and Pardee Reservoir on the Mokelumne River provides a water supply for the Cities of Oakland, Berkeley, and other east bay com- munities. Many of the major surface storage developments constructed in the Sierra Nevada, located on the principal streams of the area, have been planned primarily for irrigation water storage. The majority, however, have additional provisions for the develop- ment of hydroelectric power and for flood control. Major reservoir projects in use or under construction are Isabella on the Kern River, Pine Flat on the Kings River, Friant on the San Joaquin River, Ex- chequer on the Merced River, Don Pedro on the Tuolumne River, Melones on the Stanislaus River, Hogan on the Calaveras River, Folsom on the Ameri- can River, and Lake Almanor on the North Fork of the Feather River. Many smaller reservoirs in the Sierra Nevada provide stream regulation for hydro- electric power development, and for irrigation in the mountain and foothill areas. Irrigation districts, formed under enabling acts of the Legislature, are the principal irrigation water service agencies in the Central Valley Area. The 78 irrigation districts in the area reported approximately 1,650,000 acres irrigated in 1950. Despite the growing number of public water service agencies, there still remain several private agencies serving water to large tracts of land. These include such companies as the Kern County Land Company, Clear Lake Water Company, and Sutter Butte Canal Company. In re- cent years additional water developments, govern- mentally financed, have been provided by the United States Bureau of Reclamation, and to a lesser degree by other federal agencies such as the Corps of Engi- neers, the Indian Service, Soil Conservation Service, and Forest Service. The Central Valley Project is the most recent com- prehensive project for the irrigation of lands in the Central Valley. The original plans were made by the State of California, but the project is being con- structed and operated by the Bureau of Reclamation. The project develops surplus waters in the Sacra- mento Valley for use on certain lands in the San Joaquin Valley that formerly used water from the San Joaquin River. This permits the diversion of the San Joaquin River water southward into the Tulare Lake Basin and northward to the Madera area. The principal features of the project are Shasta and Fol- som Reservoirs in the Sacramento River Basin, and Friant Reservoir on the San Joaquin River ; the Delta Cross Channel and the Delta-Mendota Canal, includ- Harvesting Celery in the Delta Agriculture in Sacramento Valley Courtesy Siate Division of Highways CENTRAL VALLEY AREA 151 sng the Tracy Pumping Plant, utilized to transfer water developed by the Sacramento River Basin reser- voirs to the San Joaquin River area; and the Friant- Kern and Madera Canals to convey and distribute the water developed by Friant Reservoir. The sale of power from hydroelectric power plants at Shasta and Folsom Reservoirs will assist in financing- the project. Other federally authorized units of the project are the Sacramento Valley Canals, the Sly Park Project in the Cosumnes River Basin, and the Contra Costa Canal which serves lands in Contra Costa County in the San Francisco Bay Area. The outstanding- characteristic of agricultural de- velopment in the Central Valley Area during recent decades has been the increasing utilization of ground water in the development of irrigated lands. In 1929 approximately 1,300,000 acres in the area were irri- gated from ground water, portions of which also received a limited surface water supply. The 1950 United States Census of agriculture reported that land irrigated from ground water in the Central Valley Area amounted to 2,425,000 acres in 1949, while an additional 1,155,000 acres were served by combined surface and ground water supplies. A sub- stantial part of the increased use of ground water has occurred on the west side of the San Joaquin Valley, where, during the period from 1929 to 1949, the irrigated area increased from 50,000 to 542,000 acres. Lumbering and basic timber industrial installations in the Central Valley Area are centered in the Sierra Nevada, Cascade Range, Modoc Plateau, and a por- tion of the Coast Range. Plants for processing logging and milling residues to form timber by-products are located throughout the valley areas. Plywood, fiber- board, and pressed fireplace logs are among the prod- ucts of the processing industry. A fiberboard products plant near Antioch produces about 325 tons of paper products daily, utilizing cull logs and mill residues from the Central Valley Area as well as from the North Coastal Area. Processing of lumber and timber by-products which result from logging operations in the Modoc Plateau generally takes place in the North Coastal Area and in Oregon. The principal mineral producing activity in the Central Valley Area consists of the extraction of oil and gas in several fields in the southern San Joaquin Valley. Natural gas is found in widely scattered areas throughout the entire Central Valley. Gold mining, the early source of California's growth and develop- ment, which was centralized in the lower ranges of the Sierra Nevada, is no longer an important activity, largely because of the unfavorable price of gold. How- ever, several large dredging operations are still main- tained. Other mining activities in the Central Valley Area include the production of tungsten east of Fresno, mercury in the Coast Range west of Fresno, pyrites in the Redding area, gypsum near Fresno, and copper, lead, zinc, chromite, limestone, and cement in the foothills of the Sierra Nevada. Sands and gravels for aggregates are obtained commercially at many points in the valley. The principal public utilities producing and dis- tributing electric energy in the Central Valley Area are the Pacific Gas and Electric Company, with serv- ice extending throughout the major portion of the valley, and the Southern California Edison Company, serving Tulare County and small portions of Kings and Kern Counties in the southern portion of the val- ley. The California-Oregon Power Company provides service to a few communities in the area north of Shasta Dam. The Pacific Gas and Electric Company has hydroelectric generating plants on Sierra Nevada streams and on the Pit River, with an installed power capacity of 1,424,000 kilowatts, or 51 per cent of the total hydroelectric power development of the Central Valley Area. The Southern California Edison Com- pany, with developments on the San Joaquin, Kaweah, Tide, and Kern Rivers, and the Bureau of Reclama- tion, with plants on the Sacramento and American Rivers, operate the remainder of the Central Valley Area's hydroelectric power installations. The outstanding scenic attractions of the Sierra Nevada and other mountainous portions of the Central Valley Area, with their magnificent forests, lakes, and streams, have provided impetus for the establishment of innumerable commercial and private recreational areas. Major resorts are centered around such local- ities as Yosemite Valley, Clear Lake, Highways 40 and 50, and Lassen National Park, with smaller re- sorts and summer homes scattered throughout the entire mountain region. Over the years there has been a notable develop- ment of industrial activity in the Central Valley Area. Much of this increase is closely allied with agriculture, but population growth has also given rise to many service industries. There is a present trend for industrial concerns based in the eastern United States to establish subsidiary plants in Cali- fornia. Such plants now produce a sizeable percentage of the requirements of the Pacific Coast states. Some of these plants have located in the Central Valley be- cause of its strategic location as regards markets and transportation, the availability of raw materials, and the exceptional climate and living conditions. The area is believed to have a great potential for further development of industry. The trend in urban development in the Central Valley Area has been toward centralizing the various commercial and industrial activities required for the economy of the surrounding farming areas in a number of strategically located communities. New ur- ban centers have come into being with the growth in agriculture and population, and are expanding into the surrounding countryside. Cities such as Bakers- field, Fresno. Stockton, and Sacramento serve not Harvesting Cotton Near Bakersfield Courtesy California State Chamber of Commerce Vineyards in San Joaquin Valley Courtesy toe//' Chamber of Commerce CENTRAL VALLEY AREA 153 only their surrounding agricultural areas, but the en- tire economy of California. In summary, it should be emphasized that the pri- mary use of water in this area is for the production of agricultural crops. However, in the Central Valley Area, water is also utilized by urban communities, industrial plants, and for many additional purposes. In the mountains and foothills a large amount of hydroelectric power is generated at locations that combine appreciable heads with adequate water sup- plies. The streams and lakes constitute outstanding natural resources for recreational development and for propagation of fish life. Navigation on the Sacra- mento River forms an important part of the transpor- tation facilities of the valley. River barges move agri- cultural produce from the valley, and import such items as gasoline, oil, and manufactured merchandise. Repulsion of sea water from channels of the Sacra- mento-San Joaquin Delta by release of stored fresh water has kept some 372,000 acres of rich, fertile farm land in the Delta from destruction. The Sacramento River Flood Control Project constitutes a comprehen- sive system of levees, overflow weirs, and by-pass channels that controls and conveys flood waters to the sea as rapidly as possible. An expected future in- crease in upstream water storage facilities, and a greater use of water for irrigation, will increase the degree of protection provided by the present system of flood control works. There is a demand for ade- quate sustained flows in the principal streams enter- ing San Francisco Bay to permit the propagation of fish both for recreational and commercial catches. Although commercial fishing takes place off the coast and in the San Francisco Bay Area, the spawning and growth of the young of several important species take place in the Central Valley streams. Fish hatch- eries are being provided to replace upstream spawn- ing areas to which access is no longer possible. There follows a presentation of available data and estimates pertinent to the nature and extent of water requirements in the Central Valley Area, both at the present time and under conditions of probable ultimate development. PRESENT WATER SERVICE AREAS As a necessary step in estimating the amount of the water requirement in the Central Valley Area, de- terminations were made of the location, nature, and extent of irrigated and urban and suburban water service areas. Remaining lands were not classified in detail with regard to their relatively minor miscel- laneous types of water service, although such water 1 service was given consideration in estimating the present water requirement. Irrigated Lands It was determined that under present conditions of ! development in the Central Valley Area, about 4,751,000 acres are irrigated in a given year, on the average. This constitutes approximately 70 per cent of the land irrigated throughout California. Some 22 per cent of this total, or 1,032,000 acres, is in the Sacramento River Basin ; 41 per cent, or 1,957,000 acres, is in the San Joaquin River Basin ; and the re- maining 37 per cent, or 1,762,000 acres, is in the Tulare Lake Basin. The irrigated crops produced in the Central Valley Area are illustrative of the extreme diversification of agriculture in California. A substantial acreage of rice is produced in the trough of the Sacramento Valley, while cotton has become the dominant crop in the San Joaquin Valley and the Tulare Lake Basin. Irrigated orchards and vineyards are found through- out the entire area wherever soils are sufficiently deep or properly drained. Citrus fruits are produced in an extensive orchard belt on the east side of the Tulare Lake Basin, and to a small extent in Glenn and Butte Counties in the northern portion of the Sacramento Valley. Improved farming equipment and greater profit margins in the last decade have made possible the levelling and irrigation of land formerly consid- ered too rough for successful agricultural develop- ment. Considerable acreages of foothill and mountain lands are now irrigated by sprinklers, a method found to be successful for applying water to orchards and pasture on lands of rolling topography. Although ex- tensive areas are devoted to so-called truck or "cash" crops, a substantial portion of the irrigated land in the Central Valley Area is used for production of forage. Livestock raising continues to be one of the important agricultural pursuits of the area. The field surveys providing the basis for determi- nation of irrigated acreage in the Central Valley Area were accomplished during the period from 1946 through 1950, by several agencies and with varying standards and degrees of accuracy. Information re- garding the dates of field mapping and sources of data are contained in Appendix D. Based on the available survey data, the irrigated lands were classi- fied into various crop groups, with a view to segre- gating those of similar water use. The detailed segregation of individual truck and nursery crops was found to be impracticable. In some localities, data on the acreage planted to a few of the dominant truck crops were available. However, as similar data were not available throughout the area, all crops of this nature were grouped under the general heading of truck crops. In the San Joaquin River and Tulare Lake Basins, acreages of irrigated hay and grain crops were segregated from the acreage of other field crops, but in the Sacramento River Basin such segre- gation was not possible in all cases. Requirements for applied water were computed, however, on the actual area cropped to hay and grain, where applicable data were available, and are reported in the appropriate tables. Therefore, all field crops including hay and Urban Development in Central Valley Area Courtesy State Division of Highways Irrigation in the Delta Courtesy Armco Drainage and Metal Products, Inc. *4 CENTRAL VALLEY AREA 155 grain were classified as one group for that basin. A list of the various crop "roups into which irrigated lands of the Central Valley Area were classified follows : Alfalfa Hay, seed, and pasture Pasture Grasses and legumes, other than alfalfa, used for livestock forage Orchard Deciduous fruit, nuts, and olives Citrus Oranges, grapefruit, lemons Vineyard All varieties of grapes Truck crops Intensively cultivated fresh vege- tables, including tomatoes, let- tuce, melons, potatoes, and nurs- Rl ,„ ery crops Cotton Hay and grain__Barley, wheat, and other grains used as cereal or forage Miscellaneous field crops — Dried beans, milo, corn, hops, sugar beets, and unsegre- gated hay and grain in Sacra- mento River Basin It is estimated that approximately 108,000 acres in the Central Valley Area are occupied by farm lots at the present time. Of this total, 45,200 acres lie in the San Joaquin River Basin, 41,500 in the Tulare Lake Basin, and 21,400 in the Sacramento River Basin. These consist of farm buildings and areas immediately surrounding them that receive water service. Summaries of presently irrigated acreages within the Central Valley Area by the various crop groups are presented in Tables 104 and 105. Table 104 lists the acreages by hydrojjraphic units, and Table 105 by coxmties. Urban and Suburban Water Service Areas It was determined that under present conditions of development in the Central Valley Area, approxi- mately 191,000 acres are devoted to urban and subur- ban types of land use. On the floor of the valley, the urban and suburban areas were determined as part of the field surveys of irrigated lands previously mentioned. In the more mountainous regions, how- ever, such areas were determined by examination of maps and plates, and by the application of appro- priate density factors to available population data. For tlie most part, the business, commercial, and in- dustrial establishments and surrounding homes in- cluded in this areal classification receive a municipal type of water supply. Areas of urban and suburban water service within each hydrographic unit of the Central Valley Area are listed in Table 106, and within each county in Table 107. It should be noted that areas shown are gross acreages, as streets and intermingled undeveloped lands that are a part of the urban type of community are included. Unclassified Areas Remaining lands in the Central Valley Area, other than those that are irrigated or urban and suburban in character, were not classified in detail as regards present water service. However, of a total of about 32,930,000 acres of such remaining lands less than 85,000 acres actually receive water service at the pres- ent time. These relatively minor service areas consist of scattered developed portions of national forests and monuments, public parks, private recreational areas, military reservations, wild fowl refuges, etc. Migratory waterfowl reserves, feeding areas, and "•un clubs occupy approximately (12,000 acres in the Central Valley Area, of which about 15,000 acres are federal and state wild fowl management areas. The remaining acreage is composed of land utilized throughout the growing season to produce rice, but flooded late in the fall to attract wild fowl during the hunting season. National forests, monuments, and parks include nearly 13,000,000 acres of land in the Central Valley Area. For the most part, this land is in the mountain- ous regions and is covered by timber, native brush, and grass. A small portion, estimated to be about PKI. 000 acres, is presently irrigated, and is included in the values listed in Tables 104 and 105. There are many minor water service areas, consisting of scat- tered developments such as public camp and picnic areas, summer residences, trailer camps, administra- tion buildings, etc., in the forests and parks. It was estimated that approximately 5,000 acres in the Cen- tral Valley Area are devoted to these types of devel- opment, in which the use of water is minor in amount. The Division of Beaches and Parks of the State De- partment of Natural Resources at present administers 20 parks and historical monuments throughout the area. These aggregate nearly 10,000 acres, but only small portions are devoted to permanent buildings, grounds, and camping and picnic areas requiring domestic water service. The area of privately owned recreational developments in tin 1 Central Valley Area was not estimated, as it is scattered generally through- out the Sierra Nevada and the Cascade and Coast Ranges, principally in the form of summer cabins and camps. Military establishments within the Central Valley Area total about 175,000 acres, but the water-using portion is relatively small, consisting principally of administration buildings, warehouses, and quarters for personnel. 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' 2 : H = : ^ o : : : £ : (C oaJ>to «- tl ^ tl ■a -S s ^ 6 .9 i I A « g K ^5^^i5§spi 1 1 a | .S-Sx£g"p"gs| = S b §5 8-3 e 2 J; -3 g-g | O <3 < > aiUOxi-;x > w"?a h_> -5 "3 > to "3 o 3 X < H x >, < X H ■. w c 03 c : i i i-s i ►-) O i B 03 O 0) oj E L a; c3 .2 £ 3 2 x m a '3 o* « o 1—1 § CO 3 o s o GQ i 3 > "3 Sxp > Xd * "2 < X S -r. 2 x >H < > s i oj OS ^* c a tf " 3 ONOOOIOh CNCO'-P lOCOb-OOOiO — CNCO^iOOb-OOOlO^CNCO c CO CO CO CO ■* ■* f ijl f TjIrtl^fJI^lfJlO lOiOiOiOiOiCJifliflffltOOtO Navigation on Sacramento River Hydroelectric Power Plant on the Feather River Photograph by State Division of Water Resources CENTRAL VALLEY AREA 159 TABLE 105 AREAS OF PRESENTLY IRRIGATED LANDS WITHIN COUNTIES, CENTRAL VALLEY AREA (In acres) County Alfalfa Pasture Orchard Citrus Vine- yard Truck crops Rice ( 'ottoll Hay and grain Miscel- laneous field crops Net irri- Farm lots In- cluded non- water sen ice areas Approx- imate gross area Alameda Alpine Amador Butte Calaveras Colusa Contra Costa El Dorado Fresno Glenn Kern Kings Lake Lassen Madera Mariposa Merced Modoc Napa Nevada Placer Plumas Sacramento San Benito San Joaquin San Luis Obispo. Shasta Sierra Siskiyou Solano Stanislaus- Sutter Tehama Tulare... Tuolumne Ventura Yolo Yuba 800 100 ir.,900 1, til III 10.800 57,700 12,900 55,900 27,400 1,700 2,600 28,000 109,000 7,900 500 400 1,000 18,300 44,800 3,900 700 100 7,300 53,900 9,100 5,200 75,700 19,200 3,600 400 500 17.700 1,300 11.400 7.500 1,500 42,600 33,900 30,000 39,700 2,500 10.000 22.500 200 95,200 19,400 4,900 9.700 49.100 36,800 100 70,400 23,100 19.000 2,900 10,400 104,000 16.400 13,100 71,000 400 10,400 17,300 300 29,100 600 15,200 12.400 6,500 42,100 9,3Q0 3,400 7.300 4,400 5,800 300 29,300 300 700 1,500 23,200 100 8,200 30,400 1,500 7,600 44,300 39,000 9,900 32,500 1,000 11,500 9.600 o 1,300 3.900 1 ,400 1 ,500 30,900 100 200 900 196,000 100 27,400 13,400 23,900 16,100 o 100 1.900 5,900 57,900 200 21,400 700 80,400 800 100 100 100 1.600 100 1,800 18,100 35.400 400 59,800 400 1,100 2,300 15.900 200 400 14,900 100 118.000 800 6,600 14.700 8,900 400 16,300 26,100 1,200 47,100 63,400 100 4,500 35,500 o 700 10,400 4,400 6,000 6,800 3,500 56. 31 III 44,900 12,100 o o o 199,000 210,000 120.000 58,100 34,700 100 100 9 I. soo 10,800 264,000 46,300 145,000 15.400 52,200 36,500 62,900 12,200 54.400 49,000 7,600 800 200 3,000 8,000 6,900 15,200 4,000 24,100 18,500 1.000 10,800 4,300 20,200 41.100 200 1,400 2,100 25,600 1,200 48,600 11,200 4. 91 III 16,900 16,600 39,600 1,500 3,700 29,600 8.500 2,400 900 116.000 2.000 105,000 73,500 8.000 859.000 96,100 464,000 372,000 10,700 23,400 161.000 500 383,000 68,900 1,200 6,700 41,400 52,300 154,000 1,500 440,000 40,700 24,600 3,000 61,000 314,000 170,000 30,100 460.000 1,400 150,000 52.40(1 100 200 2,300 2,600 1,400 100 17,200 1,900 11.900 7,100 100 300 7,900 9.500 800 100 600 700 4.500 10,000 1,000 300 2,700 7,300 3,000 1,400 9,700 2,200 1,200 200 400 10,300 10,700 4,400 300 5,900 7,400 23,000 49.700 500 500 15,400 21,100 1,800 200 2,100 1,500 13,600 27,400 700 600 200 6,600 15,900 11,100 9,200 13,000 6,900 4.100 2,700 1,500 129,000 2,000 118,000 79,300 8,400 882,000 105,000 499,000 429,000 11,300 24,200 184,000 500 414,000 71,500 1,200 7,000 44,100 54,500 172,000 1,500 477,000 42,400 25,500 3,200 70,300 337,000 184,000 40,700 483,000 1,400 159,000 57,700 APPROXIMATE TOTALS. CENTRAL VALLEY AREA 585.000 795,000 387,000 45,000 I IS .000 346,000 295,000 723,000 757.000 370,000 4,751.000 108,000 265,000 5,123,000 Summary Table 106 comprises a summary of present water service areas within hydrographie units of the Cen- tral Valley Area. A similar summary for counties of the area is presented in Table 107. PROBABLE ULTIMATE WATER SERVICE AREAS To aid in estimating' the amount of water that will ultimately be utilized in the Central Valley Area, projections were first made to determine the probable ultimate irrigated and urban and suburban water service areas. It was assumed that the remaining lands, for convenience referred to as "other water service areas," ultimately will be served with water commensurate with their needs. Irrigated Lands Based on data from land classification surveys, it was estimated that a gross area of approximately 11,750,000 acres in the Central Valley Area is suitable for irrigated agriculture. Excepting farm lots and certain lands within the gross area that experience in- dicates will never be served with water, such as lands occupied by roads, railroads, etc. it was estimated that under ultimate conditions of development a net area of approximately 10,040,000 acres will actually be irrigated. Table 108 presents these estimates for hydrographie units of the Central Valley Area, and Table 109 for the various counties. The probable ultimate crop pattern for irrigated lands of the Central Valley Area is presented in Table 110. The crop grouping parallels that used in the case of present development except for the added group titled ''Sugar beets." This group was of minor importance and not segregated in the case of the present crop pattern, but is expected to be of greater significance in the future. 160 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 106 SUMMARY OF PRESENT WATER SERVICE AREAS WITHIN HYDROGRAPHIC UNITS, CENTRAL VALLEY AREA (In acres) Hydrographic unit Irri- gated lands Urban and sub- urban areas Approxi- mate total Hydrographic unit Irri- gated lands Urban and sub- urban areas Approxi- Reference number Name Reference number Name mate total Sacramento River Basin Mountain Units 8,400 108.000 1,900 1.700 1,600 4,600 1,600 600 2,200 86,200 23,600 9,000 27,200 3,500 100 1,700 900 1,200 200 1,000 100 600 5,700 2,200 1,300 3,600 200 8,500 1 10.000 2,800 2,900 1,800 5,600 1,600 700 2,800 91,900 25,800 10,300 30,800 3,700 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 Valley Units Antelope Plain 48,200 482.000 162.000 261.000 723,000 198.000 1,600 18.800 1,500 6,700 20,500 300 49,800 501 ,000 1 163,000 2 Pit River 268,000 3 McCloud River Sacramento River above 744,000 4 198,000 Subtotals, Valley Units APPROXIMATE TOTALS, TU- LARE LAKE BASIN San Joaquin River Basin Mountain Units Mount Diablo 5 West Side, Shasta Dam to Cottonwood Creek East Side, Cow Creek to Paynes Creek Red Bluff to Thomes Creek Antelope to Mud Creek 1.874.000 49,400 1,924,000 6 7 8 9 1.886,000 1,500 2,700 500 700 1,400 900 1.300 200 50,000 100 100 300 1,000 400 1,000 1,200 1,936,000 10_. 11 12 Butte and Chico Creeks Cortina Creek 13 Yuba and Bear Rivers. . 14 Altamont to San Luis Creek. Wist Side, Los Bancs Creek 15 16 Putah Creek _ . 1,600 Subtotals, Mountain 2,700 600 1.000 280.000 18,500 18,100 26,000 37.800 36,500 26,900 251,000 111,000 48,900 64,600 67,300 53,500 28,000 61,700 18,800 2,500 1.300 1,800 1,100 5,400 200 1,600 1,800 1.900 3,300 3,300 55,000 2,100 500 299,000 21,000 19,400 27,800 38,900 41,900 27,100 253,000 113,000 50,800 67,900 70,600 108,500 30,100 62,200 Chowchilla-Fresno Rivers Valley Units Anderson-Cottonwood Tehama .. 2,400 1,300 17 Mokelumne-Calaveras 2,300 18 19 Cosumnes River Subtotals, Mountain 1,400 20 9,200 57,200 21,500 381,000 182,000 206,000 191,000 244,000 61,700 152.000 197,000 8,600 396,000 4,100 2,700 100 1,400 2,700 4.700 1.600 4,800 400 3,100 12,900 300 1,100 21 13,300 22 23 Arbuckle. Valley LTnits Antioch _ Delta-Mendota 24 Feather River to Butte Slough . _ . _ _ Yuba-. 59,900 21,600 25 West Side, San Joaquin Valley 26 Marysville-Sheridan .. .. Woodland 382,000 27 185,000 28 Merced 211,000 29 Dixon. 193,000 30 Yolo_. 249,000 Subtotals, Valley Units. APPROXIMATE TOTALS, SACRA- MENTO RIVER B\SIN 62.100 155,000 850,000 81,800 932,000 210,000 8,900 1,130,000 9,600 1,400 100 800 101,000 500 100 1,231.000 10,100 1,500 100 800 Sacramento-San Joaquin Delta. Subtotals, Valley Units. APPROXIMATE TOTALS, SAN JOAQUIN RIVER BASIN.. 397,000 Tulare Lake Basin Mountain Units West Side, Kern County Kern River and Tehachapi 2,098,000 35,800 2,134,000 2.107,000 39,900 2,147,000 31 32 APPROXIMATE TOTALS, CEN- TRAL VALLEY AREA 5,123,000 191,000 33 Tule River 34 Kaweah River 5,314,000 35 Unclassified areas receiving wa APPROXIMATE T( WATER SERVIC Subtotals, Mountain 84,700 11,900 600 12,500 )TAL, PRE E AREA SENT 5,399,000 Urban and Suburban Water Service Areas It is expected that urban and suburban growth in the Central Valley Area generally will be associated with furl her development of agriculture, and that the problems of producing, processing, and exporting the diversity of agricultural commodities will con- tinue to be the basic source of business activity. Popu- lation increase may also be brought about by expan- sion of present and new industries. The greatest development is expected to occur in those cities adjacent to transportation facilities importing and CENTRAL VALLEY AREA 161 TABLE 107 SUMMARY OF PRESENT WATER SERVICE AREAS WITHIN COUNTIES, CENTRAL VALLEY AREA (In acres) County Irrigated lands Urban and suburban areas Approximate total 2,700 1,500 129,000 2,000 118,000 79,300 S, 1(1(1 882,000 105,000 499,000 429,000 11,300 24.200 184,000 500 414,000 71,500 1,200 7,000 44,100 54,500 172,000 1,500 477,000 42,400 25,500 3,200 70,300 337,000 184,000 40,700 483,000 1,400 159,000 57,700 1,500 10,000 1,000 1 ,300 1,800 1,400 19,300 1,500 20.100 3,200 1,400 700 2,800 300 5,800 1,000 100 1,300 4,900 1,800 .53,300 1.5,700 4,500 200 1,900 2,400 7,000 2,400 3,100 9,100 1,400 4,500 3,400 2,700 3,000 Butte -. . 140,000 3.000 119,000 81,100 9,800 901,000 Glenn .-- - 107,000 519.000 432,000 12,700 24,900 187,000 800 420,000 72.500 1 ,300 8,300 49,000 56,300 225,000 1,500 493,000 46,900 25,700 5,100 Solano 72,700 344,000 186,000 43,800 Tulare -.. 492,000 2,800 Yolo 164,000 Yuba 61,100 APPROXIMATE TOTALS, CENTRE VALLEY AREA 5,123,000 191,000 5,314,000 Unclassified areas receiving water s 84,700 RESENT "WA TER SERV- APPROXIMATE TOTAL, P ICE AREA 5,399,000 exporting commodities to and from the great Central Valley. It was estimated that under ultimate condi- tions of development the urban and suburban water service areas will increase to approximately 292,000 acres. Urban and suburban types of land use are expected to occupy the same localities as at present, but vacant lands will be filled and densities increased. In addi- tion, it is probable that encroachment will occur on surrounding lands in an estimated amount of about 105,000 acres. For purposes of the present studies no attempt was made to delineate the boundaries of such encroachment, nor to determine what proportion will be on irrigable lands. The estimate of probable ultimate urban and suburban water service areas is included in Table 112. It should be noted that the areas shown are gross acreages, including streets, vacancies, etc. Other Water Service Areas Remaining lands of the Central Valley Area, not classified as irrigable or urban and suburban under conditions of ultimate development, aggregate about 26,010,000 acres, or 68 per cent of the area. As previ- ously mentioned, it was assumed that ultimately these lands will be served with water in amounts sufficient for their needs. No attempt was made to segregate these "other water service areas" in detail in regard to the nature of their probable ultimate water service. However, as shown in Table 111, they were broken down for convenience in estimating water require- ments into those portions inside and outside of na- tional forests, monuments, and military reservations, and above and below an elevation of 3,000 feet. The lands classified as "other water service areas" include recreational developments, both public and private, military establishments, residential and industrial types of land use outside of urban communities, wild fowl refuges, etc. Most of the lands are situated in rough mountainous terrain, much of which is pres- ently inaccessible. It is expected that even under conditions of ultimate development these lands will be only sparsely settled, and will have very minor requirements for water service. Summary Table 112 comprises a summary of probable ulti- mate water service areas, segregated into irrigable lands, urban and suburban areas, and other water service areas. UNIT VALUES OF WATER USE Information obtained during recent investigations of the water resources of Sutter, Yuba, Placer, and San Joaquin Counties, and experimental data from the University of California at Davis, provided much of the basis for estimating unit values of water use in the Central Valley Area. These data were modified by standard methods to provide complete coverage of the area. Irrigation Water Use In general, unit seasonal values of consumptive use of water on lands devoted to the various irrigated crops were computed by the methods outlined in Chapter II. Individual analysis was made in order to determine the unit seasonal values of consump- tive use for rice, hay and grain, and winter potatoes, for which the growing seasons and cultural practices were not readily adaptable to the standard procedure. The methods used for these crops are described in Chapter II. 6—99801 162 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 108 PROBABLE ULTIMATE AREAS OF IRRIGATED LANDS WITHIN HYDROGRAPHIC UNITS, CENTRAL VALLEY AREA (In acres) Hydrograplue unit Ref- erence num- ber 9. 10_ 11. 12_ 13_ 14- 15. 16. 17_. 18.. 19-. 20_ . 21.. 22.. 23-. 24_ . 25.. 26.. 27_ . 28.. 29.. 30.. 31. 32 33 34 35 Name Sacramento River Basin Mountain Units Goose Lake Pit River McCloud River Sacramento Ri ver aboveShastaDam West Side, Shasta Dam to Cotton- wood Creek East Side, Cow Creek to Paynes Creek Red Bluff to Thomes Creek. Antelope to Mud Creek Stony Creek Butte and Chico Creeks Cortina Creek Feather River Yuba and Bear Rivers Cache Creek American River.. Putah Creek Subtotals, Mountain Units Valley Units Anderson-Cotton- wood Tehama Vina Orland Chico Arbuckle Colusa Trough Feather River to Butte Slough Yuba Marys ville-Sheri- dan Woodland Carmichael Dixon.. _. Yolo Subtotals, Valley Units APPROXI- MATE TOTALS, SACRA- MENTO RIVER BASIN Tulare Lake Basin Mountain Units West Side, Kern County Kern River and Tehachapi Mountains Tule Rn er Kaweah River Kings River Subtotals, Mountain Units Gross irrigable area 29,400 400,000 25,100 10,900 41,100 105,000 52,200 13,000 .52,700 19,400 52,400 246,000 160,000 77,200 110,000 43,100 1,444,000 28,400 101,000 82,300 137,000 91,300 119.000 507,000 245,000 74.200 200,000 180,000 236,000 105,000 180.000 2,346,000 3,790,000 I 1,700 181,000 31,800 15,800 1 1 ,900 252,000 Farm lots 300 4,300 300 100 500 1,100 500 100 600 200 500 2,500 1,800 1,000 1,400 400 15,600 400 1,300 1,200 1,700 2,300 1,400 5,900 3,100 1,200 2,400 2,100 2,800 2,300 2,000 30,100 45,700 200 \400 500 200 100 3,400 Included nonwater service area 4,000 49,500 3,200 1,500 4,500 13,300 6,800 1,600 7.200 2,800 6,900 50,900 29.400 9,500 17,100 5,300 213,000 3,500 12,400 9,400 15,500 10,100 13,300 65,300 33,700 8,600 33,900 21,100 37,700 19,400 24,500 308,000 521,000 1 ,500 19,500 3,800 1,900 1 ,300 28,000 Approxi- mate net irrigated area 25,100 346,000 21,000 9,800 36,100 90,300 44,900 1 1 ,300 44,900 16,400 45,000 193,000 135,000 66,700 91,800 37,400 1,215,000 24,500 87.700 71,700 120,000 78,900 104,000 436,000 208.000 64,000 164,000 157.000 196,000 143,000 153,000 2,008,000 3,223,000 10,000 159,000 27,500 13,700 10,500 221.000 Hydrograpliic unit Ref- erence num- ber 36... 37... 38... 39. .. 40... 41., . 42. 43. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. Name Valley Units Antelope Plain... Kern. Earlimart Visalia Fresno-Hanf ord . . Tulare Lake Subtotals, Valley Units APPROXI- MATE TOTALS, TULARE LAKE BASIN... San Joaquin River Basin Mountain Units Mount Diablo Altamont to San Luis Creek West Side, Los Banos Creek to Avenal Creek San Joaquin River Chowchilla-Fresno Rivers Merced River Tuolumne River.. Stanislaus River.. Mokelumne-Cala- veras Rivers Cosumnes River.. Subtotals, Mountain Units Valley Units Antioch Delta-Mendota... West Side, San Joaquin Valley- Madera Merced Los Banos Modesto Vernalis Oakdale Stockton lone Sacramento-San Joaquin Delta . Subtotals, Valley L T nits APPROXI- MATE TOTALS, SAN JOAQUIN RIVER BASIN APPROXI- MATE TOTALS, CENTRAL VALLEY AREA Gross irrigable 451,000 962,000 394,000 419,000 1 ,005,000 254,000 3,485,000 3,737.000 12,000 33,800 50,400 5,000 24,500 44,600 37,900 20,100 68,900 62,200 365,000 67,200 72,100 785,000 422,000 463,000 293,000 384,000 82,100 214,000 489,000 150,000 439,000 3,860,900 4,225,000 1 1 ,750,000 Farm lots 7,600 15,000 6,300 5,400 17,200 3,900 55,400 58,800 200 400 700 300 400 500 300 1,100 800 4.700 1,300 1,000 11,400 6,200 6,100 4,100 r,,300 1,200 3,500 6,900 1,900 6,400 50,300 61,000 166,000 Included Approxi- nonwater mate net service i irrigated area area 56,500 118.000 48,700 47,400 1 25,000 33,600 429,000 387,000 829,000 339,000 366,000 863,000 216,000 3,000,000 157,000 3,221,000 1.300 I 10,500 3,900 29,500 6,200 100 3,800 9,600 5,700 5,100 14,100 10,400 60,200 7,400 7,500 91,000 56,500 70,200 37,600 52,200 8,600 27,500 80,200 33,000 37.400 43,500 4,900 20,400 34,600 31,700 20,700 53,700 51,000 509.000 569, 300,000 58,500 63,600 683,000 359,000 387,000 251,000 320,000 72,300 183,000 402,000 115,000 395,000 3,295,000 3,595,000 1.547.000 10,040,000 CENTRAL VALLEY AREA 163 TABLE 109 PROBABLE ULTIMATE AREAS OF IRRIGATED LANDS WITHIN COUNTIES, CENTRAL VALLEY AREA (In acres) County Gross irri- gable area Farm lots Included nonwater service area Approxi- mate net irrigated area 3,900 300 08,000 393,000 98,900 373,000 86.000 91,700 1,470,000 318,000 1,411,000 695,000 78,700 104,000 445,000 47,700 787,000 228.000 25,600 59,500 213,000 133,000 438.000 24,200 822,000 5,200 2 14,000 17,1(10 46,400 227.000 567,000 323,000 223,000 1.017.000 49,100 200 389,000 197,000 100 700 4,300 900 4.300 1,500 1,000 18,900 3,700 18,100 20,900 900 1 ,300 8,000 400 1 1 ,000 2,300 300 600 1,900 1,200 5,900 300 1 1 ,400 100 2,600 600 500 3,200 7,900 4,600 3,200 14,100 700 5,500 2,600 500 13,000 65,400 19,300 48,100 2,100 15.. ".00 181,000 37,000 175,000 74,900 9,500 14,200 55,900 10,400 109.000 27.000 2,900 10,200 36,600 24,100 71,200 3,000 118,000 600 26,300 1 1 ,500 5,100 27,900 78,000 40,200 26,100 119,000 7,800 46,600 34,600 3,300 Alpine-- - — Amador Butte 300 54,300 323,000 78,700 321,000 82,400 75,200 1,270,000 Glenn 277,000 1.218,000 599,000 68,300 88,500 Madera - 381,000 36,900 667,000 Modoc ... . 199,000 Napa- ... — Nevada. Placer . . . - .. 22,400 48,700 175,000 108,000 Sacrament j- San Benito 361,000 20,900 693,000 4,500 215,000 35,300 40,800 Solano- . _ Stanislaus- . . Sutter- . . ._ - - 196,000 481,000 278,000 194,000 Tulare Tuolumne- _ . - 884,000 40,600 200 Yolo 337,000 160,000 APPROXIMATE TOTALS, CENTRAL VALLEY AREA 11,750,000 166,000 1,547,000 10,040,000 An appreciable difference in the average precipita- tion between the northern and southern ends of the Central Valley has a profound effect on the require- ment for irrigation water. Grain, for example, is successfully produced without irrigation in the Sacra- mento Valley, whereas irrigation is necessary through- out most of the San Joaquin River and Tulare Lake Basins. Temperature differences throughout the Cen- tral Valley Area also have an appreciable effect on the water requirement. The short, mild winters and long, warm growing seasons in the southern portion of the valley floor permit year-round production of crops. Potatoes and grain are grown during the win- ter, and diverse field and truck crops during the sum- mer season. In the mountain valleys the short grow- ing seasons generally limit crops to alfalfa or pasture. Table 113 presents the estimated unit values of mean seasonal consumptive use of applied irrigation water and of precipitation on lands devoted to crops of the various groups. Unit mean seasonal consumptive use of applied water on farm lots was estimated to be about 0.5 foot of depth. Estimates of unit mean seasonal consump- tive use of precipitation on farm lots varied from 0.5 foot to 2.0 feet in the various hydrographic units of the Central Valley Area, and averaged about 1.1 feet of depth. These estimates were employed for both present and probable ultimate conditions of development. Urban and Suburban Water Use Present unit seasonal values of use of water on urban and suburban water service areas of the Cen- tral Valley Area were estimated largely on the basis of available records of delivery of water to the areas, as compiled by municipalities and other public water service agencies. Probable ultimate values of water deliveries were estimated by applying to the present values derived percentage factors to account for ex- pected future increase in population densities and in per capita water use. Table 114 presents the estimates of present and probable ultimate unit mean seasonal values of gross water deliveries to and consumptive use of water in urban and suburban water service areas. Use of Water in Other Water Service Areas Unit values of water use on the miscellany of serv- ice areas grouped in this category were derived gen- erally from data on measured or estimated present deliveries of water to the typical development in- volved. In most cases the estimates were made in terms of per capita use of water, and the actual acreage of the service area was not a significant fac- tor. In such cases the aggregate amount of water deliveries is relatively very small, and negligible re- covery of return flow is involved. For purposes of study, therefore, the estimated unit values of delivery of water to these facilities were considered to be also the measures of consumptive use of applied water. Both the National Forest and Park Services pro- vided estimates of present and probable ultimate unit deliveries of water to all facilities within their juris- diction. The estimates were generally in terms of per capita use of water, and were based on actual measure- ments and experience. They varied widely from place to place and in type of use, and for this reason are not detailed herein. The value of unit use of water by military estab- lishments was derived on a per capita basis, from available records of delivery of water, flow through sewage plants, and estimates of population of the camps involved. The average daily per capita use at McClellan Field near Sacramento in 1950-51 was ap- proximately 190 gallons. It was assumed that this value will hold in the future. 164 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 110 PROBABLE ULTIMATE PATTERN OF IRRIGATED CROPS, CENTRAL VALLEY AREA (In acres) Hydrographic unit Alfalfa Pasture Orchard Citrus Vine- yard Truck crops Rice Cotton Sugar beets Hay and grain Miscel- laneous field crops Approxi- mate total Refer- ence number Name 1 Sacramento River Basin Mountain Units 10,600 18,000 1,000 5,000 2,000 2,000 18,200 3,000 2,000 9,400 172,000 12,400 5,500 18,400 53,100 21,400 7,500 21,000 8,100 14,000 136,000 71,400 24,400 38,200 13,000 200 200 1,000 600 1,000 2,500 1,000 13,400 11,200 9,000 25,200 1,200 500 1,000 5,000 300 200 100 3,000 3,000 4,900 94,900 9,200 3,400 16,500 35,600 15,400 2,800 11,800 5,800 14,400 12,400 41,000 14,100 17,700 10,200 61,000 200 100 3,100 10,100 13,600 12,100 10,400 13,200 5,700 8,000 25,100 2 Pit River 346,000 3 McCloud River - 21,600 4 Sacramento River above Shasta 9,300 5 West Side, Shasta Dam to Cotton- 36,100 6 East Side, Cow Creek to Paynes 90,300 7 g Red Bluff to Thomes Creek 44,900 11,300 9 44,900 10 16,400 11 45,000 12 193,000 13 135,000 14 66,700 15 91,800 16 37,400 Subtotals, Mountain Units Valley Units 17 61,800 3,000 22,200 10,000 35,000 5,000 10,000 40,900 25,500 4,000 7,300 30,000 15,100 37,300 19,000 626,000 11,700 17,900 16,000 12,000 10,000 11,000 35,600 16,000 7,000 26,300 10,000 36,000 13,900 11,000 66,500 1,200 6,500 21,000 9,000 18.000 12,000 22,000 31,300 26,000 20,000 14,100 9,000 10,300 6,500 500 2,000 500 1,000 6,000 1,000 5,000 2,000 4,500 5,000 4,500 6,000 4,500 15,600 4,000 6,600 600 1,000 400 1,000 5.000 12.000 7,000 4,000 12,000 12,000 7,000 8,800 10,000 7,000 20.000 5,000 160,000 68,100 10,000 48,000 33.000 26,000 61,000 10,100 15,000 25,000 1,000 5,000 3,000 65,000 30,000 7,000 29,700 14,400 24,500 20,000 310,000 7,000 15,000 13,700 1 1 ,000 8,800 16,100 30,500 15,000 3,900 17,800 11,200 38,300 12,500 8,200 138,000 26,100 9,000 29,000 11,100 25.000 40,000 9,000 5,000 20,000 12,300 34.100 35,700 10,000 1,215,000 24,500 18 87,700 19 71.700 20 120,000 21 78,900 22 104,000 23 436,000 24 25 Feather River to Butte Slough Yuba 208,000 64,400 26 164,000 27 157,000 28 196,000 29 143,000 30 Yolo 153,000 Subtotals, Valley Units APPROXIMATE TOTALS, SACRAMENTO RIVER BASIN - 264,000 234,000 207,000 3,500 52,100 83,800 438,000 50,100 209,000 209,000 266,000 2,008,000 326,000 2,000 20,300 1,200 3,500 1,100 860,000 1,800 40,800 2,900 3,300 5,700 273,000 6,200 2,200 2,000 4,000 58,100 2,000 13,000 5,000 1,000 90,400 1,000 13,000 1.000 1,000 438,000 50,100 33,900 9,100 200,000 519,000 3,200 29,200 6,100 3,900 2,700 404,000 3,000 3,223,000 31 32 Tulare Lake Basin Mountain Units West Side, Kern County Kern River and Tehachapi Moun- 10,000 159,000 33 Tule River -- 27,500 34 13,700 35 10,500 Subtotals, Mountain Units Valley Units Antelope Plain. 36 37 28.100 42,000 106,000 40,000 55,000 70,000 15,000 54,500 18,400 56,500 21,600 11,700 20,600 22,700 10,400 6,000 12,900 9,000 38,000 75,000 15,000 30,300 34,700 20,000 21,000 10,000 45,000 !.->.( Kill 50,000 234,000 16,000 30,000 51,700 20,000 10,800 12,000 5,600 10,000 10,000 43,000 225,000 497,000 140,000 125,000 310,000 130,000 5,000 10,000 8,000 5,600 45,100 25,300 34,700 18,000 21,200 36,900 12,200 3,000 25,100 14.900 20,000 66,200 14,800 221,000 387,000 829,000 38 339.000 39 366,000 40 863,000 41 216,000 Subtotals, Valley Units APPROXIMATE TOTALS, TULARE LAKE BASIN_ 328,000 152,000 141,000 100,000 384,000 130,000 20,000 1,427,000 28,600 148,000 141,000 5,000,000 356,000 207,000 151,000 100,000 405,000 146,000 20,000 1,470,000 28,600 193,000 144,000 3,221,000 CENTRAL VALLEY AREA TABLE 110— Continued PROBABLE ULTIMATE PATTERN OF IRRIGATED CROPS, CENTRAL VALLEY AREA (In acres) 165 Hydrographic unit Alfalfa Pasture Orchard Citrus Vine- yard Truck crops Rice Cotton Sugar beets Hay and grain Miscel- laneous field crops Refer- ence number Name Approxi- mate total 42 San Joaquin River Basin Mountain Units Mount Diablo 2,000 7,000 2,000 900 9,100 9,000 4,900 11,400 25,100 16,800 12,200 30,100 26,600 2,600 5,000 4,000 1,000 2,000 8,000 2,200 3,600 8,300 1,000 1,000 5,000 2,000 2,000 3,000 3,100 6,100 6,000 2,000 2,300 2,000 10,000 2,000 1,000 1,000 5,100 10,500 3,900 4,500 2,900 2,100 12,100 7,000 1,000 1,000 100 1,000 1,100 1,800 3,100 10,500 43 44 Altamont to San Luis Creek West Side, Los Banos Creek to A venal Creek . 29,500 43,500 45 San Joaquin River _ 4,900 46 47 Chowchilla- Fresno River Merced River.. 20,400 34,600 48 Tuolumne River 31,700 49 Stanislaus River 20,700 50 51 Mokelumne-Calaveras Rivers Cosumnes River 53,700 51,000 Subtotals, Mountain Units Valley Units Antioch 52 11,000 15,900 13,000 80,500 36,000 35,000 50,000 51,000 23,300 21,500 56,000 6,000 30,500 146,000 3,000 14,000 34,700 25,200 28,800 15,000 42,000 6,000 15.000 36,900 54,300 25,200 36,700 14,800 5,000 30,000 15,000 27,100 14,000 25,000 6,000 50,500 50,000 4,000 5,700 29,200 2,000 3,000 20,000 35,000 27,000 1,000 36,000 1,000 25,000 63,000 5,000 6,300 6,500 6.000 32,000 5,000 13,000 8,000 15,800 13,000 10,000 29,600 7,000 136,000 5,000 40,500 78,600 40.000 20,400 5.000 15,000 75,000 700 13,000 5,000 361,000 156,000 100,000 75,000 30,900 4,600 3,000 2,800 16,000 3,500 9,800 4,000 3,000 10,000 35,000 49,100 2,700 7,600 32,500 12,900 21,600 10,600 26,500 3,100 7,000 25,100 30,400 111,000 9,100 4,000 10,000 88,900 31,000 39.600 34,000 68,500 10,900 35,500 56,200 8,100 51,000 300,000 58,500 53 Delta-Mendota 63,600 54 55 West Side, San Joaquin Valley Madera 683,000 359,000 56 Merced 387,000 57 Los Banos 251,000 58 Modesto ... 326,000 59 Vernalis 72,300 60 Oakdale 183,000 61 Stockton. 402,000 62 lone 115,000 63 Sacramento-San Joaquin Delta Subtotals, Valley Units APPROXIMATE TOTALS, SAN JOAQUIN RIVER BASIN 395,000 419,000 300,000 247,000 218,000 282,000 280,000 728.000 91,700 291,000 438,000 3,295,000 430,000 446,000 284,000 247,000 288.000 280,000 741,000 91,700 340,000 447,000 3,595,000 APPROXIMATE TOTALS, CENTRAL VALLEY AREA 1,112,000 1,513,000 708,000 104,000 710,000 524,000 738,000 2,261,000 320,000 1,052,000 995,000 10,040,000 The water requirement for milling- of lumber was determined on the basis of units of production. It was estimated that the milling process uses one gallon of water per board-foot of lumber produced, that pulp processing requires 56,000 gallons per 1,000 board- feet of chips, and that the manufacture of fiberboard utilizes 2,300 gallons per 1,000 board-feet of material processed. In addition to the foregoing, the consump- tive use of water by evaporation from logging ponds was estimated to be about 3 acre-feet per 10,000,000 board-feet of lumber produced. The California Department of Fish and Game, the United States Fish and Wildlife Service, and private individuals operating duck clubs provided informa- tion on the quantity of water used for migratory waterfowl refuges and hunting clubs in the Central Valley Area. Federal and state refuges are operated throughout the year, and the estimated seasonal con- sumptive use of water is 3.0 acre-feet per acre. This figure was based on estimates of total applied water, which varied from 4.5 acre-feet to 6.0 acre-£«>et per acre per season. Most private clubs are operated only during the hunting season, and it was estimated that the mean seasonal consumptive use of applied water is 1.0 acre-foot per acre per year. For other water service areas not encompassed by the foregoing specific types of water service, unit values of consumptive use of applied water under probable ultimate conditions of devlopment were as- signed on a per capita basis. In such areas, sparse residential, industrial, and recreational development is expected in the future. For areas outside national forests, monuments, and military reservations, it was estimated that the ultimate population density will average about eight persons per square mile, and that per capita consumptive use of water will be about 70 gallons per day. In areas inside national forests, monuments, and military reservations the same per capita use estimates were made, but the population density was assumed to average about four persons per square mile. The period of water use was assumed to be of only three months' duration during the sum- 166 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 111 OTHER WATER SERVICE AREAS UNDER PROBABLE ULTIMATE CONDITIONS, CENTRAL VALLEY AREA (In acres) Hydrographie unit Inside national forests, monu- ments, and military reservations Outside national forests, monu- ments, and military reservations Approximate total Reference number Name Above 3,000-foot elevation Below 3,000-foot elevation Above 3,000-foot elevation Below 3,000-foot elevation 1 Sacramento River Basin Mountain Units 222,000 1,855,000 248,000 155,000 144,000 88,000 131,000 161,000 156,000 29,500 1,553,000 517.000 52,200 818,000 130,000 53,000 27,400 22,000 10,900 15,900 78,300 116,000 95,800 52,400 65,800 77,300 12,400 977,000 78,400 69,100 91,800 161,000 4,100 43,000 58,200 314,000 30,100 4,400 15,200 700 74,300 32,400 132,000 516,000 452,000 332,000 234,000 305,000 95,800 214,000 177,000 330,000 531,000 286,000 300,000 234,000 2.- Pit River 3,036,000 3 McCloud River _ __ 412,000 4 383,000 5 774,000 6 712,000 7 483,000 8 516,000 9 _ 577,000 10 183,000 11 . 214,000 12 2,140,000 13 930,000 14.. 653,000 15 1,197,000 16 Putah Creek 361,000 Subtotals, Mountain Units - . . -_ Valley Units 17 6,130,000 745,000 1,859,000 4,071,000 5,900 25,900 52,300 6,800 13,800 5,900 70,200 94,900 5,300 13,400 17,500 10.800 49,900 16,900 12,800,000 5,900 18 19 - Tehama, ------ - - — 25,900 52,300 20 6,800 21. ___ . 13,800 22 5,900 23 70,200 24.. 94,900 25 Yuba 5,300 26 Marysville-Sheridan . _ 13,400 27 17,500 28 29 Carmichael _ . 10,800 49,900 30 Yolo 10,900 389,000 389,000 APPROXIMATE TOTALS, SACRAMENTO RIVER BASIN Tulare Lake Basin Mountain Units 31 6,130,000 1,282,000 185,000 250,000 872,000 745,000 30,000 23,000 9,400 83,700 1,859,000 19,000 737,000 25,600 59,800 12,200 4,460,000 275,000 605,000 200,000 276,000 206,000 13,190,000 294,000 32 2,654,000 33 . Tule River . 434,000 34 595,000 35 1,174,000 2,589,000 146,000 854,000 1,562,000 247,000 175,000 36,800 38,600 81,900 600 5,151,000 36 Valley Units 247,000 37 38 39 40 Kern - Earlimart Visalia _._ _ _ _ 175,000 36,800 38,600 81,900 41 Tulare Lake __. 600 580,000 580,000 APPROXIMATE TOTALS, TULARE LAKE BASIN 2.589,000 146.000 854,000 2,142,000 5,731,000 CENTRAL VALLEY AREA 167 TABLE 111 -Continued OTHER WATER SERVICE AREAS UNDER PROBABLE ULTIMATE CONDITIONS, CENTRAL VALLEY AREA (In acres) Hydrographic unit Inside national forests, monu- ments, and military reservations Outside national forests, monu- ments, and military reservations Approximate total Reference number Name Above 3,000-foot elevation Below 3.000-foot elevation Above 3,000-foot elevation Below 3,000-foot elevation 42 San Joaquin River Basin Mountain Units 898,000 49,600 483,000 770,000 486,000 250,000 104,000 41,800 1,300 41,800 36,100 31,200 2,900 1,000 4,000 85,900 3,600 22,200 15,300 17,300 1,300 87,300 51,100 88,800 445,000 726,000 168,000 319,000 359,000 168,000 159,000 320,000 207,000 89,800 43 449,000 44 .. 812,000 45- 1,112,000 46 392,000 47.. 899,000 48-- 991,000 49 678,000 50 663,000 51 425,000 3,041,000 155,000 289,000 3,026,000 13,600 1,900 3,000 58,100 54,900 117,000 59,200 3,400 36,800 61,000 121,000 39,000 6,511,000 52 Valley Units 13,600 53 Delta-Mendota - 1,900 54 3,000 55 Madera .. . . . _ 58,100 56 Merced . . . . . . 54,900 57 117,000 58 59,200 59 3,400 60 Oakdale _ _. - 30,800 61 Stockton . _. .- 61,000 62 lone . _ _. 121,000 63 Sacramento-San Joaquin Delta _ . . Subtotals, Valley Units APPROXIMATE TOTALS, SAN JOAQUIN RIVER BASIN 39,000 569,000 569,000 3,041,000 155,000 289,000 3,595,000 7,080,000 APPROXIMATE TOTALS, CENTRAL VALLEY AREA. 11,760,000 1,046,000 3,002,000 10,200,000 26,010,000 mer for areas above 3,000 feet in elevation, while water service for areas below 3,000 feet in elevation was assumed to be throughout the year. CONSUMPTIVE USE OF WATER In general, estimates of the amounts of water con- sumptively used in the Central Valley Area were derived by applying appropriate unit values of water use to the service areas involved. The estimates repre- sent the seasonal amount of consumptive use of water under mean conditions of water supply and climate. Table 115 presents estimates of present consumptive use of applied water and precipitation in areas having water service, and Table 116 presents corresponding estimates for probable ultimate conditions of develop- ment. FACTORS OF WATER DEMAND In addition to the amount of water consumptively used in a given service area, certain factors relating to the water requirements, such as necessary rates, times, and places of delivery of water, quality of water, losses of water, etc., have to be given consider- ation in the design of water development works. In the Central Valley Area the most important of these demand factors are associated with the supply of water for irrigation. Of secondary importance are those related to the supply of water for urban, sub- urban, recreational, hydroelectric power generation, and other uses. The demand factors most pertinent to design of works to meet water requirements of the Central Valley are discussed in the following sections. Monthly Distribution of Water Demands Within the season, the demand for irrigation water in the Central Valley Area generally varies from little or none during the winter rainy months to more than 15 per cent of the seasonal total during dry summer months. In a portion of the west side of the San Joaquin Valley, off-season potatoes require the greatest amounts of irrigation water during the winter period. Available data indicate that consider- able variation in water demand also occurs with crop and soil types, as well as with latitude and elevation above sea level. Urban water demands, while sub- 168 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 112 SUMMARY OF PROBABLE ULTIMATE WATER SERVICE AREAS, CENTRAL VALLEY AREA (In acres) Hydrographic unit Refer ence num- ber 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. :;t 35. Name Irrigable lands Sacramento River Basin Mountain Units Goose Lake Pit River McCloud River.. Sacramento River above Shasta Dam West Side, Shasta Dam to Cotton- wood Creek East Side, Cow Creek to Paynes Creek Red Bluff to Thomes Creek _ Antelope to Mud Creek Stony Creek Butte and Chico Creeks Cortina Creek Feather River Yuba and Bear Rivers Cache Creek American River Putah Creek Subtotals, Mountain Units Valley Units Anderson- Cottonwood Tehama Vina Orland Chico Arbuckle Colusa Trough-.. Feather River to Butte Slough .. Yuba Marysville- Sheridan Woodland Carmichael Dixon Yolo Subtotals, Valley Units APPROXI- MATE TOTALS, SACRA- MENTO RIVER BASIN ... Tulare Lake Basin Mountain Units West Side, Kern County Kern River and Tehachapi Mountains Tule River Kaweah River Kings River Subtotals, mluin Units 29,400 400,000 25,100 10,900 41,100 105,000 52,200 13,000 52,700 19,400 52,400 246,000 166,000 77,200 110,000 43,100 Urban and suburban areas 1,444,000 28,400 101,000 82,300 137,000 91,300 119,000 507,000 245,000 74,200 200,000 180,000 236,000 165,000 180,000 2,346,000 3,790,000 11,700 181,000 31,800 15,800 11,900 300 3,900 1,400 2,11(10 Other water service areas 400 1,500 500 100 500 1,200 500 8,900 6,000 2,000 6,400 400 234,000 3,036,000 412,000 383,000 774,000 712,000 483,000 516,000 577,000 183,000 214,000 2,140,000 930,000 653,000 1,197,000 361,000 Approxi- mate total 36,000 3,500 2,200 1,800 1,400 5,400 600 2,000 1,800 2,400 3,300 3,500 60,000 2,200 500 90,600 12,800,000 5,900 25,900 52,300 6,800 13,800 5,900 70,200 94,900 5,300 13,400 17,500 10,800 49,900 16,900 389.000 264,000 3,440,000 438,000 396,000 815,000 819,000 536,000 529,000 630,000 204,000 267,000 2.395.000 1,102,000 732,000 1,313,000 405,000 14,280,000 37,800 129,000 136,000 145,000 1 1 1 .000 126,000 579,000 341.000 81,900 217,000 201,000 307.000 217,000 197,000 2,826,000 127,000 13,190,000 100 1,800 400 200 100 252,000 2.600 294,000 2,654,000 434,000 595,000 1,174,000 5,151,000 17,110,000 306,000 5,406,000 Hydrographic unit Refer- ence num- ber 36. 37. 38. 39. 40- 41. 42 _ 43. 44... 45. 46. 47. 48. 49. 50. 51. 52. 53 _ 54. 55. 56. 57. 58_ 59. 60_ 61. 62. 63 _ Name Valley Units Antelope Plain Kern Earlimart Visalia Fresno-Hanford _ . Tulare Lake Subtotals, Valley Units. APPROXI- MATE TOTALS, TULARE LAKE BASIN. ._ San Joaquin River Basin Mountain Units Mount Diablo Altamont to San Luis Creek West Side, Los Banos Creek to Avenal Creek __ San Joaquin River Chowchilla-Fresno Rivers Merced River Tuolumne River . . Stanislaus River . . Mokelumne-Cala- veras Rivers Cosumnes River... Subtotals, Mountain Units Valley Units Antioch Delta-Mendota... West Side, San Joaquin Valley. Madera Merced Los Banos Modesto Vernalis Oakdale Stockton lone Sacramento-San Joaquin Delta _ Subtotals, Valley Units APPROXI- MATE TOTALS, SAN JOA- QUIN RIVER BASIN... APPROXI- MATE TOTALS, CENTRAL VALLEY AREA |ll,750,000 Irrigable lands 451,000 962,000 394,000 419,000 1,005,000 254,000 Urban and suburban areas Other water service areas Approxi- mate total 3.-IS.-I.0IMI 3,737,000 12,000 33,800 50,400 5,000 24,500 44,600 37,900 26,100 68,900 62,200 3,000 24.300 3,400 10,600 38,200 1.600 81,100 83.700 247,000 175,000 36,800 38,600 81.900 600 580.000 701,000 1,161,000 434,000 469,000 1,125,000 256,000 4.146,000 5,731,000 9.5.32,000 100 89.800 300 449,000 365,000 67,200 72,100 785,000 422,000 463,000 293,000 384,000 82,100 214,000 489,000 150,000 439,000 500 100 200 800 2,700 1,000 1,700 1.900 3,860,000 4,225,000 9,300 13,600 500 5,100 3,800 5,600 2,700 8,500 600 3,200 24,100 900 2,900 812,000 1,112,000 392,000 899,000 991,000 678,000 663,000 425,000 71,500 80,800 6,511.000 13.600 1,900 3,000 58,100 54,900 117,000 59,200 3,400 36,800 61,000 121,000 102,000 483,000 863,000 1,117,000 417,000 944,000 1,032,000 705,000 734.000 489,000 0,880,000 94,400 74,500 793,000 484,000 523,000 413,000 452,000 86,100 254,000 574,000 272,000 39,000 | 481,000 569,000 7,080,000 292,000 26,010.000 4,501,000 i i ::'.io.ooo 38,050,000 CENTRAL VALLEY AREA 169 TABLE 113 ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, CENTRAL VALLEY AREA (lr feet of depth) Hydrographio unit Alfalfa Pasture Orchard Citrus Vineyard Cotton Refer- ence num- ber Name Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total 1 ... Sacramento River Basin Mountain Units Goose Lake. Pit River 1.7 1.4 1.1 1.6 2.8 3.0 1.8 1.6 1.5 1.7 2.5 2.2 2.6 1.5 2.6 1.7 2.6 2.1 2.2 2.3 2.1 2.3 2.5 2.7 2.5 2.7 2.6 2.6 2.6 2.6 2.6 2.6 2.7 2.5 2.6 2.5 3.1 3.3 3.1 2.7 3.1 3.1 3.1 2.9 2.9 2.8 2.9 1.0 1.4 1.7 1.6 1.5 1.5 1.3 1.6 1.2 1.9 1.2 1.4 1.3 1.3 1.3 1.3 1.5 1.3 1.4 1.3 1.3 1.2 1.2 1.3 1.3 1.3 1.2 1.2 1.2 1.2 0.6 0.7 0.8 1.2 0.7 0.5 0.5 0.7 0.9 0.7 0.5 2.8 3.0 3.2 3.3 4.0 3.7 3.9 3.1 3.8 3.6 3.8 3.5 3.5 3.6 3.4 3.6 4.0 4.0 3.9 4.0 3.9 3.8 3.8 3.9 3.9 3.9 3.9 3.7 3.8 3.7 3.7 4.0 3.9 3.9 3.8 3.6 3.6 3.6 3.8 3.5 3.4 1.2 0.8 1.1 1.5 2.3 2.3 2 2.3 3 McCloud River .. 4 Sacramento River above Shasta Dam.. ... West Side, Shasta Dam to Cotton- wood Creek. .. 1.4 1.9 3.3 0.9 1.4 1.4 1.5 0.7 1.6 0.9 1.6 2.0 1.3 1.3 1.3 1.3 1.4 1.7 1.5 1.7 1.6 1.6 1.7 1.6 1.6 1.6 1.6 1.5 1.6 1.5 1.6 1.6 1.5 1.4 1.7 1.3 1.8 1.3 1.5 1.4 1.4 1.3 1.5 1.6 1.3 1.4 1.3 1.4 1.3 1.2 1.3 1.3 1.3 1.3 1.3 1.3 1.3 2.5 3.0 2.9 2.9 2.4 2.9 2.7 2.9 3.5 2.7 2.7 2.6 2.8 3.0 3.0 2.9 3.0 3.0 2.9 2.9 2.9 2.9 2.9 2.9 2.8 2.9 2.8 5 6 East Side, Cow Creek to Paynes Creek Red Bluff to Thomes Creek .. Antelope to Mud Creek 2.0 2.4 1.7 1.5 3.7 3.9 7 8 9 Stony Creek Butte and Ghico Creeks 2.3 1.4 2.4 1.8 1.5 2.2 1.4 1.4 3.8 3.6 3.8 3.2 10 11 ( Hitina Creek Feather River . Yuba and Bear Rivers . 12 2.1 1.4 1.3 1.2 3.4 2.6 13 0.9 1.2 2.1 14 Cache Creek- American River 2.0 1.6 3.6 15 1.0 1.2 2.2 16 Putah Creek Valley Units Anderson-Cotton- wood - Tehama Vina 2.0 2.2 2.4 2.3 2.6 2.3 2.4 2.5 2.3 2.5 2.3 2.5 2.3 2.4 2.4 3.1 3.3 3.1 2.7 3.1 3.1 3.1 2.9 2.9 2.8 2.9 1.6 1.8 1.6 1.6 1.4 1.6 1.4 1.3 1.6 1.4 1.6 1.4 1.4 1.4 1.3 0.6 0.7 0.8 1.2 0.7 0.5 0.5 0.7 0.9 0.7 0.5 3.6 4.0 4.0 3.9 4.0 3.9 3.8 3.8 3.9 3.9 3.9 3.9 3.7 3.8 3.7 3.7 4.0 3.9 3.9 3.8 3.6 3.6 3.6 3.8 3.5 3.4 17 0.9 1.2 1.4 1.2 2.3 2.4 18 19 1.8 1.2 3.0 20 Orland 1.8 1.2 3.0 1.2 1.1 1.2 1.3 1.1 1.1 1.1 1.1 1.1 1.2 1.1 2.5 2.5 1.5 1.2 1.2 1.1 1.0 1.2 1.2 1.2 1.2 1.2 1.1 1.2 0.6 0.7 0.8 2.4 2.3 2.3 2.3 2.3 2.3 1.4 1.1 2 5 21 ( Iiico 22 23 24 Arbuckle Colusa Trough Feather River to Butte Slough ... Yuba Marysville- Sheridan Woodland ' 'annichael Dixon Yolo 1.9 1.7 1.0 1.2 2.9 2.9 1.4 1.4 1.0 1.0 2.4 2.4 25 26 2.3 2.3 2.3 2.3 2.3 3.1 3.2 2.3 27 28 29 1.7 1.1 2.8 30 31 Tulare Lake Basin Mountain Ljnits West Side, Kern County . . Kern River and Te- hachapi Moun- 32 2.3 2.1 1.7 2.2 2.3 2.3 2.1 2.0 2.1 0.7 0.8 1.2 0.7 0.5 0.5 0.7 0.9 0.7 3.0 2.9 2.9 2.9 2.8 2.8 2.8 2.9 2.8 2.3 2.1 1.7 0.7 0.8 1.2 3.0 2.9 2.9 2.2 2.0 0.7 0.8 2.9 2.8 33 34 Tule River Kaweah River Kings River. . . Valley Units Antelope Plain Kern Earlimart 35... . 1.5 2.5 2.5 2.3 2.2 2.2 0.7 0.5 0.5 0.7 0.9 0.7 2.2 3.0 3.0 3.0 3.1 2.9 36 37 38 39 2.3 2.1 2.0 2.1 6.5 0.7 0.9 0.7 2.8 2.8 2.9 2.8 2.3 2.3 2.1 1.9 2.0 2.2 0.5 0.5 0.7 0.9 0.7 0.5 2.8 2.8 2.8 2.8 2.7 2.7 40 41 Fresno-Hanford Tulare Lake. ._ 170 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 113-Continued ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, CENTRAL VALLEY AREA (In feet of depth) Hydrographic unit Alfalfa Pasture Orchard Citrus Vineyard Cotton Refer- ence num- ber Name Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total Ap- plied water Pre- cipita- tion Total 42 San Joaquin River Basin Mountain Units Mount Diablo Altamont to San Luis Creek. West Side, Los Banos Creek to Avenal Creek San Joaquin River Chowchilla-Fresno 2.6 2.9 2.9 1.2 0.8 0.8 3.8 3.7 3.7 2.7 2.9 2.9 2.5 2.7 2.2 2.3 2.6 2.5 1.9 2.8 2.9 3.1 2.9 2.8 3.0 2.7 2.9 2.6 2.5 2.7 2.6 1.1 0.8 0.8 1.1 1.1 1.3 1.5 1.2 1.4 1.6 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.2 1.0 0.9 3.8 3.7 3.7 3.6 3.8 3.5 3.8 3.8 3.9 3.5 3.7 3.7 3.6 3.7 3.8 3.7 3.7 3.8 3.7 3.7 3.7 3.5 1.7 2.0 2.0 1.5 1.7 1.4 1.3 1.3 1.5 1.1 1.9 2.1 2.3 2.0 1.9 2.1 1.8 2.0 1.7 1.5 1.8 1.4 1.2 0.8 0.8 1.2 1.2 1.2 1.5 0.7 1.4 1.6 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.3 1 .1 1.1 2.9 2.8 2.8 2.7 2.9 2.6 2.8 2.0 2.9 2.7 2.8 2.9 2.8 2.8 2.9 2.8 2.8 2.9 2.8 2.8 2.9 2.5 1.2 1.1 2.3 43 44 2.4 0.8 3.2 2.3 0.8 3.1 45 46 1.2 1.0 0.9 1.2 1.1 0.9 1 .4 1.5 2.5 2.1 1.3 1.6 1.2 1.4 1.2 1.2 1.2 1.0 1.2 1.4 1. 1 1.2 1.3 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.1 1.1 2.2 2.2 2.3 2.3 2.3 2.2 2.3 2.3 3.0 2.9 2.3 2.3 2.2 2.3 2.3 2.3 2.3 1.9 1.7 1.1 1.4 3.0 47 3.1 48 49 50 Mokelumne-Cala- 51 52 Valley Units Antioeh Delta-Mendota West Side, San Joa- quin Valley Madera Merced Los Banos Modesto Vernalis Oakdale. - Stockton lone Sacramento-San Joaquin Delta _ _ 2.8 2.9 3.1 2.9 2.8 3.0 2.7 2.9 2.6 2.4 2.6 2.4 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.3 1.1 1.1 3.7 3.7 3.6 3.7 3.8 3.7 3.7 3.8 3.7 3.7 3.7 3.5 54 1.6 2.3 1.7 1.4 1.7 1.4 0.8 0.5 0.8 1.0 0.7 1.0 2.4 2.8 55 56 57 58 59 2.0 0.8 2.8 2.5 2.4 2.4 2.4 60 61 62 1.8 1.1 2.9 63 Hydrographic unit Rice Truck crops Hay and grain Miscellaneous field crops Sugar beets Refer- ence number Name Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total 1... _. Sacramento River Basin Mountain Units Goose Lake 0.5 0.4 0.4 0.5 0.8 0.8 1.1 1.2 1.3 1.2 1.2 1.2 1.6 1.6 1.7 1.7 2.0 2.0 1.0 0.7 0.8 1.0 0.4 0.7 0.5 0.3 0.5 0.3 0.7 0.3 0.8 0.5 0.6 0.4 1.0 1.2 1.3 1.1 1.3 1.2 1.2 1.3 1.2 1.7 1.1 1.1 1.0 1.1 1.1 1.2 2.0 1.9 2.1 2.1 1.7 1.9 1.7 1.6 1.7 2.0 1.8 1.4 1.8 1.6 1.7 1.6 0.6 0.5 1.1 1.2 1.7 1.7 2 Pit River 3 McCloud River _ _ _ 4 Sacramento River above Shasta Dam 0.6 0.9 1.2 1.2 1.8 2.1 5 West Side, Shasta Dam to Cottonwood Creek r> East Bide, ( !ow Creek to Paynes Creek. Red Bluff to Thomes Creek 7 1.0 1.2 2.2 8 Antelope to Mud Creek 9 Stonv Creek . . 1.0 1.0 2.0 10 Butte and < !hico Creeks 0.5 1.5 2.0 11 ' lortina ' 'reek 1.0 0.8 1.0 0.8 0.9 0.7 1.1 1.2 1.1 1.2 1.1 1.2 2.1 2.0 2.1 2.0 2.0 1.9 12 Feather River 13 Yuba and Bear Rivers ... 0.8 0.8 1.1 1.1 1.9 1.9 14 Cache Creek.. Lg American River . _ 16 Putah Creek 0.7 1.1 1.8 CENTRAL VALLEY AREA 171 TABLE 113-Continued ESTIMATED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF WATER ON IRRIGATED LANDS, CENTRAL VALLEY AREA (1 n feet of depth) Hydrographic unit Rice Truck crops Hay and grain Miscellaneous field crops Sugar beets Refer- ence number Name Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total Ap- plied water Pre- cipi- ta- tion Total 17 ... Sacramento River Basin — Continued Valley Units 0.8 0.9 0.8 0.9 0.8 0.9 0.9 0.8 0.9 0.8 0.9 0.8 0.9 0.7 1.1 0.9 1.2 0.8 1.2 1.1 1.1 1.1 1.1 1.0 1.0 1.1 1.0 1.1 1.0 1.0 1.0 1.1 0.6 0.7 0.8 1.1 2.0 2.0 1.9 2.0 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.8 1.9 1.8 1.7 1.6 2.0 1.9 0.4 0.6 0.5 0.6 0.5 0.5 0.6 0.6 0.7 0.6 0.5 0.5 0.5 0.5 0.7 0.6 1.3 0.9 1.3 0.8 0.8 0.6 0.5 0.6 0.8 0.3 0.3 0.5 1.3 1.1 1.2 1.1 1.2 1.1 1.0 1.1 1.0 1.1 1.1 1.1 1.1 1.1 0.6 0.7 0.8 1.1 0.7 0.5 0.5 0.7 0.9 0.7 0.5 1.1 0.8 0.8 1.7 1.7 1.7 1.7 1.7 1.6 1.6 1.7 1.7 1.7 1.6 1.6 1.6 1.6 1.3 1.3 2.1 2.0 2.0 1.3 1.3 1.3 1.4 1.3 1.3 1.4 1.1 1.3 0.9 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.1 1.0 1.0 1.0 1.0 0.9 1.3 1.1 1.1 1.1 1.1 1.0 1.0 1.1 1.0 1.1 1.0 1.0 1.0 1. 1 2.2 2.1 2.1 2.1 2.1 2.0 2.0 2.1 2.1 2.1 2.0 2.0 2.0 2.0 18 19_ 1.5 1.2 2.7 | 20 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.1 1.1 1.1 1.0 1.0 1.1 1.0 1.1 1.0 1.0 5.2 5.2 5.1 5.1 5.2 5.1 5.2 5.1 5.1 21 1.6 1.5 1.6 1.6 1.3 1.6 1.6 1.5 1.6 1.5 1.0 2.7 22 2.6 23 24 25 Colusa Trough Feather River to Butte Slough 2.6 2.7 2.4 26 27 28 29 Marysville-Sheridan Woodland Carmichael 2.7 2.7 2.6 2.7 30. Yolo 4.1 1.1 5.2 2.6 31 Tulare Lake Basin Mountain Units West Side, Kern County. _ 32 Kern River and Tehachapi Mountains _ Tule River... 1.5 0.7 2.2 33 34 Kaweah River . 35 Kings River. _ . 36 Valley Units Antelope Plain 1.0 1.0 0.5 0.7 0.8 1.0 0.7 0.8 0.7 0.5 0.5 0.7 0.9 0.7 0.5 1.1 0.8 0.8 1.5 1.5 1.2 1.6 1.5 1.5 1.8 1.6 1.5 1.6 1.5 1.3 1.2 1.3 1.5 0.9 0.5 0.5 0.7 0.9 0.7 0.5 1.1 2.1 2.0 2.0 2.1 2.0 2.0 2.0 2.0 2.0 1.8 1.6 1.7 1.9 0.5 0.5 0.7 0.9 0.7 0.5 2.5 37 Kern _ _ 2.5 38 Earlimart 2 5 39 2 5 40 41 Fresno- Hanford 4.1 4.1 0.7 0.5 4.8 4.6 2.4 2 4 42 San Joaquin River Basin Mountain Units Mount Diablo 43 Altamont to San Luis Creek 44 West Side, Los Banos Creek to Avenal Creek . 1.2 0.8 2.0 45 San Joaquin River . 46 Chowchilla-Fresno Rivers 0.8 0.6 0.6 1.1 1.3 1.3 1.9 1.9 1.9 0.9 0.7 0.8 1.3 0.9 0.6 0.4 0.5 1.2 0.5 0.4 0.6 0.4 0.5 0.3 0.3 0.4 1.5 1.1 1.3 1.2 0.7 1.2 1.3 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.3 1.1 1.1 2.0 2.0 2.0 2.0 2.1 1.9 1.3 1.3 1.7 1.3 1.4 1.3 1.4 1.4 1.4 1.6 1.5 2.6 0.9 1.1 2.0 47 Merced River.. . _ 48 Tuolumne River 0.8 1.7 0.9 0.6 1.1 1.2 1.5 1.2 1.0 1.3 1.0 1.2 0.9 0.8 1.0 2.0 1.2 1.2 1.2 1.3 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.2 1.1 0.9 2.0 2.9 2.1 1.9 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.1 2.0 2.0 2.1 2.9 49 Stanislaus River 50 Mokelumne-Calaveras Rivers . 51 Cosumnes River __ _ _ 52 San Joaquin River Basin Valley Units Antioch __ 4.1 0.9 5.0 0.9 1.0 1.0 1.0 0.8 1.1 0.8 0.9 0.7 0.9 0.8 1.5 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 0.9 1.1 1.0 1.8 1.8 1.5 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.9 2.5 1.7 1.8 2.0 1.8 1.6 1.9 1.6 1.8 1.5 1.4 0.9 0.8 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.2 2 6 53 Delta-Mendota _ _ 2 6 54 55 West Side, San Joaquin Valley Madera .. ._ _ 4.1 4.1 4.1 4.1 4.1 4.1 4.1 4.1 0.5 0.8 1.0 0.7 1.0 0.9 1.1 1.2 4.6 4.9 5.1 4.8 5.1 5.0 5.2 5.3 2.5 2 6 56 Merced. . 2 6 57 58 Los Banos Modesto _ 2.6 2 6 59 Vernalis 2.7 2 6 50 Oakdale 51 Stockton . _ 2.6 52 lone ... 53 Sacramento-San Joaquin Delta 4.1 1.1 5.2 1.7 1.1 2.8 172 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA stantially higher in summer than in winter months, are far more uniform throughout the season than are those for irrigation. They vary from four to six per cent of the seasonal total during the months of December through March, to over 10 per cent from June through September. Representative data on monthly distribution of irrigation and urban water demands in the Central Vallev Area are presented in Table 117. Irrigation Water Service Area Efficiency In the study of irrigation water requirements of the Central Valley Area it was found to be desirable to estimate the over-all efficiency of irrigation prac- tice in the various service areas. Irrigation water service area efficiency was measured by the ratio of consumptive use of applied irrigation water to the gross amount of irrigation water delivered to a service area. Present irrigation water service area efficiencies were estimated after consideration of geo- logic conditions of the service areas involved, their topographic position in relation to sources of water supply and to other service areas, consumptive use of water, irrigation efficiency, usable return How, and urban and suburban sewage outflow. Extensive data concerning present irrigation prac- tices in the Central Valley Area are available, and provided the basis for the estimates of water service area efficiencies which were formulated during the current study. Data on seasonal quantities of surface water diverted by present water service agencies are available from records maintained by these agencies, and from data compiled by the Sacramento-San Joa- quin Water Supervision, an activity of the State Division of Water Resources. Irrigation efficiencies were computed by comparing recorded surface diver- sions of water with calculated consumptive use values for the areas served by various operating agencies. It was indicated that the irrigation efficiencies range from 40 to 65 per cent for most areas on the valley floor, and are about 50 per cent in the areas lying at higher elevations. Studies conducted by the Division of Water Re- sources in Sutter and Yuba Counties and in San Joaquin County resulted in the conclusion that irriga- tion efficiencies are somewhat higher when water supplies are obtained by pumping from "round water storage. In the Sutter- Yuba area during 1947-1948 the irrigation efficiency was approximately 48 per cent. In San Joaquin County the average irrigation efficiency attained with water supplies obtained from ground water during the 1948-49 season was approxi- mately 52 per cent. Data available from records of power consumption by agricultural loads in the west side of (he San Joaquin Valley in Fresno and Merced Counties, for 1948-49, indicate that the average irri- gation efficiency was approximately 60 per cent. As a result of the analysis, irrigation water service] area efficiencies for various portions of the Central Valley Area under present conditions were found to range from 40 to 90 per cent, with the higher effi- ciencies occurring in areas principally supplied by development of the ground water resources. It was estimated that ultimate efficiencies would be some- what higher, as a result of anticipated improved agri- cultural technology. Additional factors affecting the estimates of probable ultimate irrigation water serv- ice area efficiencies were related to the location and extent of presently undeveloped irrigable lands, as well as the increased costs of water development. For purposes of illustration, the weighted mean values of all irrigation water service area efficiencies within each hydrographic unit of the Central Valley Area are presented in Table 118. WATER REQUIREMENTS As the term is used in this bulletin, water require- ments refer to the amounts of water needed to pro- vide for all beneficial uses of water and for irrecover- able losses incidental to such uses. Those water requirements of the Central Valley Area that are primarily nonconsumptive in nature are discussed in general terms in the ensuing section. Following this, water requirements that are consumptive in nature are evaluated, both for present and for prob- able ultimate conditions of development. Requirements of a Nonconsumptive Nature The principal water requirements of a noncon- sumptive nature in the Central Valley Area are asso- ciated with the preservation and propagation of fish and wildlife, flood control, salinity repulsion from the delta, navigation, and hydroelectric power. For the most part, such requirements for water are ex- tremely difficult to evaluate other than in conjunc- tion with definite plans for water resource develop- ment. Their consideration in this bulletin, therefore, is limited to discussion of their implications as re- lated to planning for future development of water resources. Fish and Wildlife. The Central Valley Area is of primary importance to hunting and fishing in Cali- fornia. The spawning areas in the streams and the numerous wild fowl refuges also contribute greatly to the maintenance of these sports throughout the Pacific Coast. A significant contribution to the econ- omy of the State is made through expenditures by fishermen and hunters, and through returns to com- mercial fisheries. The recreational resources of the area are particularly attractive to residents of crowded metropolitan areas, many of whom come to the Cen- tral Valley Area for hunting, fishing, and general recreation. Most of the many species of fish and game present in California can be found in this area. CENTRAL VALLEY AREA 173 TABLE 114 ESTIMATED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY AND CONSUMPTIVE USE OF WATER IN URBAN AND SUBURBAN AREAS, CENTRAL VALLEY AREA (In feet of depth) Hydrographic unit Present Probable ultimate Hydrographic unit Present Probable ultimate Refer- ence num- ber Name Gross delivery Con- sump- tive use of applied water Gross delivery Con- sump- tive use of applied water Refer- ence num- ber Name Gross delivery Con- sump- tive use of applied water Gross delivery Con- sump- tive use of applied water Sacramento River Basin Mountain Units Goose Lake Pit River. . _ 0.7 0.7 0.7 0.7 0.7 0.7 0.9 0.9 1.3 0.5 0.5 0.8 0.8 1.6 1.2 0.7 0.9 0.8 2.6 1.3 0.9 1.4 0.7 1.5 1.0 1.2 0.7 0.8 0.8 0.4 0.4 0.4 0.4 0.4 0.4 0.5 0.5 0.7 0.3 0.3 0.4 0.4 0.8 0.6 0.4 0.5 0.4 1.3 0.7 0.5 0.7 0.4 0.8 0.5 0.6 0.4 0. t 0.4 1.8 1.8 1.8 1.8 2.4 2.4 2.6 2.4 2.6 2.2 2.6 1.8 2.4 2.4 2.4 2.4 2.8 2.8 2.8 2.8 2.8 2.6 2.6 2.8 2.6 2.6 2.6 2.4 2.4 2.4 2.8 2.6 2.6 0.9 0.9 0.9 0.9 1.2 1.2 1.3 1.2 1.3 1.1 1.3 0.9 1.2 1.2 1.2 1.2 1.4 1.4 1.4 1.4 1.4 1.3 1.3 1.4 1.3 1.3 1.3 1.2 1.2 1.2 1.4 1.3 1.3 34 35 36... _ 37 38 39 40 41 12 43 44 45 46. _. 47 48 49.... 50.. 51 52 53 54 55 56 57 58 59 60 61 62 63 Mountain Units — Continued 0.8 0.8 1.8 2.2 2.2 2.5 2.8 0.7 0.8 0.9 0.8 0.8 0.9 0.5 0.5 1.9 0.7 0.1 2.5 1.6 1.3 2.0 1.1 1.0 1.9 0.6 1.3 0.4 0.4 0.9 1.1 1.1 1.3 1.4 0.4 0.4 0.5 0.4 0.4 0.5 0.3 0.3 1.0 0.4 0.1 1.3 0.8 0.7 1.0 0.6 0.5 1.0 0.3 0.7 2.6 2.6 2.8 2.8 2.8 2.8 2.8 2.8 2.6 2.6 2.6 2.4 2.6 2.6 2.6 2.6 2.6 2.4 2.6 2.8 2.8 2.6 2.6 2.8 2.6 2.8 2.6 2.4 2.4 2.4 1.3 1 1.3 2 Valley Units 3 4 ... Sacramento River above 1 .4 1.4 5 West Side, Shasta Dam to 1.4 1.4 6 East Side, Cow Creek to 1.4 1 4 7 8 9 Red Bluff to Thomes Creek Antelope to Mud Creek San Joaquin River Basin Mountain LTnits Mount Diablo 10 Butte and Chico Creeks 1 3 11 Altamont to San Luis Creek- West Side, Los Banos Creek to A venal Creek. 1 3 12 13 14 Yuba and Bear Rivers Cache Creek .. 1.3 1 2 15 Chowchilla-Fresno Rivers.. 1 3 16.... Putah Creek.. 1 3 Valley Units Anderson-Cottonwood . Tehama. . Tuolumne River. 1.3 1.3 17 18.._- Mokelumne-Calaveras 1 3 19 Vina 1 2 20 Valley Units 21 Chico ... 22 Arbuckle . _ . _ _ . 1 3 23 Colusa Trough.. . . 1 4 24 25 FeatherRiverto Butte Slough Yuba West Side, San Joaquin Valley 1 4 26.... Marysville-Sheridan Woodland _ 1 3 27 1.3 1 4 28 Carmichael.. 29 Dixon . 1.3 1 4 30 Yolo Tulare Lake Basin Mountain Units West Side, Kern County Kern River and Tehachapi Mountains _ Oakdale 1.3 Stockton ... 1.2 lone .. 1.2 31 32... Sacramento-San Joaquin Delta.. ... 1.2 33 Tule River.. The anadromous fishes found in the Central Valley Area include striped bass, king salmon, steelhead, shad, and sturgeon. A major portion of their lives is spent in the ocean, although they return to fresh water to spawn. With the exception of steelhead, the bulk of the anadromous fishes of the State is pro- duced in the Sacramento-San Joaquin river system. Virtually all of the striped bass caught in California are produced in this area, as are 70 per cent of the salmon. Tn addition, salmon from the Central Valley Area are caught at sea along the coasts of Oregon. Washington, and British Columbia. The California Department of Fish and Game estimates the mini- mum animal value of these anadromous fishes to be $27,500,000 in the Central Valley Area, based upon sportsmen's expenditures and receipts of commercial fishermen. The fishery for these species is concentrated in the Delta area, and in that portion of the Sacramento River and its tributaries that lie in the valley or low foothills. The San Joaquin River and its tributaries, once of great importance to salmon spawning, are of little value to these fisheries at the present time due to insufficient stream flow. Trout provide the principal form of angling in the numerous streams and lakes of the mountainous por- tions of the Central Valley Area. Rainbow trout are the most numerous, but eastern brook trout are plen- tiful at higher elevations. Golden trout, the Califor- nia State fish, are found in the high lakes and streams 174 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA from Yosemite National Park south through the Kern River. Brown trout are also taken in many streams and lakes in the area, particularly those at lower elevations. The lakes, streams, and reservoirs of the foothill areas and of the valley support populations of black bass, crappies, catfish, and other warm-water fishes. Clear Lake, in Lake County, and the Sacramento-San TABLE 115 ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF WATER ON PRESENT WATER SERVICE AREAS, CENTRAL VALLEY AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Unclassified areas Approximate Refer- Name total consumptive ence number Applied water Precipitation Applied water Applied water Applied water use of applied water 1 Sacramento River Basin Mountain Units 10,800 109,000 2,800 2,400 2,400 8,200 1,600 1,100 2,000 88,700 42,300 13,900 35,300 4,700 8,300 136.000 3,200 2,400 2,300 6,400 2,500 600 3,800 104,000 30,100 11,900 33,300 4,500 100 600 600 200 100 200 500 300 400 100 300 300 3,800 1,300 300 1,300 100 1,000 100 200 100 600 300 200 300 100 3,500 1,900 200 800 10,900 2 Pit River 111,000 3 McCloud River . 3,200 4 3,000 5 6 West Side, Shasta Dam to Cottonwood Creek. 2,600 9,100 7 Red Bluff to Thomes Creek 300 8 1,800 9 1,400 10 2,400 11 12 96,600 13 45.700 14 14,500 15 37,600 16 Putah Creek 4,800 325,000 40,100 30,800 34,400 79,500 90,600 41,900 717,000 292,000 100,000 142,000 161,000 104,000 45,900 150.000 349,000 25,700 18,300 28,700 42,700 40,100 26,500 245,000 126,000 54,000 71,200 70,000 57,600 29,600 63,700 1,800 100 400 300 600 400 400 2,000 1,100 400 700 700 800 600 600 8,700 2,000 800 600 500 2,200 300 1,000 800 1,300 1,100 2,400 28,800 1,200 200 9,300 700 44,200 13,500 700 2,000 100 345,000 42,200 17 Valley Units 18 Tehama 32,000 19 35,300 20 Orland 80,600 21 Chico -__-- . . 93,900 22 42,600 23 Colusa Trough . . 764,000 24 Feather River to Butte Slough _ _. 307,000 25 Yuba 102,000 26 144,000 27 Woodland 164,000 28 136,000 29 47,700 30 Yolo 151,000 2,029,000 899,000 9,100 43,200 61,200 2,142,000 APPROXIMATE TOTALS, SACRAMENTO RIVER BASIN 2,354,000 23,800 3,500 300 2,300 1,248,000 7,200 1,100 100 700 10,900 100 51,900 200 100 70,500 400 200 100 400 2,487,000 31 Tulare Lake Basin Mountain Units 32 33 Kern River and Tehachapi Mountains. _ Tule River 24.500 3,800 34 400 35 2,700 Subtotals, Mountain Units . Valley Units 36. 29,900 55,100 958,000 303,000 523,000 1,455,000 256,000 9,100 18,100 230,000 106,000 214,000 510,000 93,500 100 1,900 5,200 1,700 2,700 7,300 1,900 300 600 16,900 1,700 7,400 27,300 400 1,100 1,400 700 31,400 58,000 37 982,000 38... 306,000 39 Visalia .. . _. 533,000 40 Fresno-Hanford _ 1,490,000 tl Tulare Lake.. 258,000 Subtotals, Valley Units .. _ 3,550,000 1,172,000 20,700 54,300 2,100 3,627,000 APPROXIMATE TOTALS, TULARE LAKE BASIN 3,580,000 1,181,000 20,800 54,600 3,200 3,658,000 CENTRAL VALLEY AREA 175 TABLE 115— Continued ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF WATER ON PRESENT WATER SERVICE AREAS, CENTRAL VALLEY AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Unclassified areas Approximate total consumptive Refer- Name ence number Applied water Precipitation Applied water Applied water Applied water use of applied water 42 San Joaquin River Basin Mountain Units 2,000 6,200 1,000 1,400 2,300 2,100 3,000 400 1,200 2,700 500 900 2,100 1,000 1,800 400 100 100 400 200 300 300 500 200 2,200 700 700 900 600 43 44 45 West Side, Los Banos Creek to Avenal Creek 2,000 6,800 46 . 1,200 47 3,700 48 3,400 49 3,000 50 4,200 51 1,300 18,400 103,000 24,800 566,000 317,000 398,000 401,000 394,000 114,000 289,000 321,000 9,000 619,000 10,600 47,200 16,100 185,000 134,000 184,000 134,000 236,000 50,500 157,000 209,000 4,900 410,000 100 600 300 3,900 1,900 2,900 1,500 3,100 600 1,300 2,700 700 3,100 1,300 2,600 100 3,300 3,700 1,100 5,000 200 1,600 12,200 100 700 5,800 100 3.600 21,500 100 25,600 52 Valley Units 106,000 53 Delta-Mendota. ... .. . _ 25,100 54 570,000 55 Madera ______ 322,000 56 408,000 57 425,000 58 402,000 59 60 61 62 Vernalis _ Oakdale Stockton 115,000 292,000 336,000 9,800 63 623,000 Subtotals, Valley Units .. 3,556,000 1,768,000 22,600 30,600 25,300 3,634,000 APPROXIMATE TOTALS, SAN JOAQUIN RIVER BASIN 3,574,000 1,779,000 22,700 31,900 31,100 3,660,000 APPROXIMATE TOTALS, CENTRAL VALLEY AREA 9,508,000 4,208,000 54,400 138,000 105,000 9,805,000 Joaquiu Delta are especially important to warm-water fishing. Irrigation canals and farm ponds also provide significant numbers of these fish. The great Central Valley is the most important waterfowl area in California, and in addition plays an important role in the welfare of waterfowl on the entire Pacific Flyway. It is used mainly as a winter- ing area, and to a lesser degree for breeding. Approx- imately 3,500.000 ducks and geese are found in the valley each winter, and an average of 115,000 birds are produced there annually. The California Depart- ment of Fish and Game and the United States Fish and Wildlife Service maintain several waterfowl refuges and management areas in the area. The Central Valley Area far exceeds the other parts of the State in opportunities for deer hunting. An estimated deer population of almost 500,000 pro- vides about one-half of the annual deer take of Cali- fornia. Black bear are numerous in some localities, and the Central Valley Area also supports several herds of antelope. These latter are hunted only when census figures indicate that such hunting is desirable. Two small herds of elk, and a band of Sierra Nevadan bighorn sheep for which hunting is prohibited, are of particular interest to naturalists. Upland game birds consist of ring-necked pheasants, quail, and mourning doves. Sage hens and chukar partridges, when their hunting is permitted, and band-tailed pigeons also provide sport in local areas. Among the upland game mammals are cottontail, brush, and jack rabbits, and tree squirrels. The quantities of water required to maintain or enhance these resources vary among the different groups. Auadromous fishes, particularly salmon and steelhead which spawn farther upstream than the others, require substantial flows of water in order that they can spawn successfully, and that the eggs can hatch. Such flows of water are necessary principally during the fall and winter months. At low dams or other barriers to migration, fishways are necessary in order that the migrant fishes can cross the barriers. Such fishways require a flow of water for their suc- cessful operation. Resident fishes usually require smaller quantities of flowing water, but the requirement is year-round rather than seasonal. Flowing streams are needed 176 WATER UTILIZATION x\ND REQUIREMENTS OF CALIFORNIA throughout the year to insure satisfactory food pro- duction and spawning conditions for trout. In fluc- tuating reservoirs it is necessary to establish mini- mum pool elevations, so that fish populations will have sufficient water to support them at all times. Water requirements for ducks and geese are sub- stantial, and occur mainly during the fall and winter months. It is probable that much of the fresh water required to maintain waterfowl habitat in the future will be available from waste and return flows, TABLE 116 PROBABLE MEAN SEASONAL CONSUMPTIVE USE OF WATER ON ULTIMATE WATER SERVICE AREAS, CENTRAL VALLEY AREA (In acre-feet) Hydro-graphic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Approximate Refer- Name total consumptive ence number Applied water Precipitation Applied water Applied water Applied water use of applied water 1 Sacramento River Basin Mountain Units 39,700 398,000 26,000 13,000 54,200 144,000 78,500 12,800 75,300 17,800 66.900 361,000 216,000 94,600 134.000 47,200 26,300 458,000 33,100 13,000 50,900 125,000 55,900 17.400 52,500 29,800 51,200 240.000 162.000 83,800 114.000 47,100 100 2,100 100 100 200 500 300 100 300 100 300 1,500 900 500 700 200 300 3.500 1,300 1,800 500 1,800 700 100 700 1,300 700 8,000 7,200 2.400 7,700 500 14,000 500 600 800 1,200 900 600 1,000 200 200 12,400 15,100 1,000 4,600 400 40,100 2 Pit River -- . .. 418.000 3 McCloud River _ _ 27,900 4 15,500 5 6 7 West Side, Shasta Dam to Cottonwood Creek . East Side Cow Creek to Paynes Creek _ Red Bluff to Thomas Creek _ . 55,700 147,000 80,400 8 13,600 9 77,300 10 19,400 11 68 100 12 383,000 13 239,000 14 98,500 15 147,000 16 48,300 1,779,000 41,700 147,000 108,000 227,000 164,000 158,000 1,101,000 507,000 127,000 372,000 341,000 343,000 227,000 391,000 1,566,000 36,200 112,000 96,400 148,000 97,600 116,000 461,000 252,000 76,800 194,000 180,000 223,000 169,000 176,000 8,000 200 700 600 800 1,200 700 2,900 1,500 600 1,200 1,100 1,400 1,200 1,000 38,500 4,900 3,100 2,500 2,000 7,600 800 2,600 2,500 3,100 4,300 4,600 72,000 2,600 600 53,500 700 117,000 38,500 1,400 2,000 100 1.879,000 46,800 17 . Valley Units 18 151 000 19 20 . Vina . 1 1 1 ,000 230 000 21 174 000 22.. 159,000 23. 1,223,000 550,000 132,000 24 . 25... Yuba 26 377,000 27 347,000 28. _. 418 000 29 231,000 30 Yolo 393,000 4,255,000 2,338,000 15,100 113,000 160,000 4,543,000 APPROXIMATE TOTALS, SACRAMEN- TO RIVER BASIN 6,034,000 20,000 350,000 48,200 26,400 26.200 3,904,000 6,000 118,000 25,100 15,800 6,800 23,100 100 1,200 200 100 100 152,000 100 2,300 500 300 100 213,000 300 1,800 500 500 1,000 6,422,000 20 500 31 Tulare Lake Basin Mountain Units 32 355 000 33 Tule River 49,400 27,300 27 400 34 35 Subtotals, Mountain Units 471,000 844,000 1,911,000 707,000 732,000 1,763,000 484,000 172,000 193,000 423,000 237,000 322,000 647,000 108,000 1,700 3,800 7,500 3,100 3,300 8,600 1,900 3,300 4,200 34,000 4,800 14,800 53,500 2,200 4,100 16,400 700 480,000 36. __ . Valley Units Antelope Plain ._ . 852,000 37 1,969,000 715 000 38 Earlimart ... 39 Visalia.. 750 000 40 Fresno-Hanford _ . _. .... 1 826,000 41.. Tulare Lake . _ . 488 000 Subtotal*, Valley Units 6,441,000 1,930.000 28,200 114,000 17,100 6,600,000 APPROXIMATE TOTALS, TULARE LAKE BASIN... 6,912,000 2,102,000 29,900 117,000 21,200 7,080,000 CENTRAL VALLEY AREA 177 TABLE 116— Continued PROBABLE MEAN SEASONAL CONSUMPTIVE USE OF WATER ON ULTIMATE WATER SERVICE AREAS, CENTRAL VALLEY AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Approximate Refer- Name total consumptive ence number Applied water Precipitation Applied water Applied water Applied water use of applied water 42 San Joaquin River Basin Mountain Units Mount Diablo . 15,900 61,500 82,700 12,300 46,200 63,700 54,100 43,900 98,800 71,400 12,000 23,600 35,600 5,400 18,600 44,900 46,600 23,100 71,100 68,800 100 200 300 100 200 300 100 600 400 100 400 700 100 300 1,000 3,500 1,300 2,200 2,300 100 400 800 1,300 500 4,300 1,200 1,600 1,600 1,000 16,200 62 500 43. - 44 45.. West Side, Los Banos Creek to Avenal Creek 84,500 13 700 46 47,100 69,200 59,100 46,900 47. 48 49 Stanislaus River 50 Mokelumne-Calaveras Rivers 103,000 51 Cosumnes River 75,100 550,000 126,000 123,000 1,517,000 758,000 813,000 581,000 556,000 153,000 321,000 789,000 201,000 668,000 350,000 52,600 50,900 341,000 302,000 379,000 186,000 342,000 62,900 201,000 490,000 121,000 424,000 2,300 700 500 5,700 3,100 3,100 2,000 3,100 600 1,800 3,500 1,000 3,200 11,900 17,700 700 7,100 4,900 7,300 3,800 11,000 800 4,200 29,000 1,100 3,500 12,800 5,000 15,000 34,000 100 577,000 144,000 124,000 1,530 000 52 Valley Units 53 54 West Side, San Joaquin Valley 55 Madera .- . 771,000 838,000 621 000 56 57 Los Banos. . 58 Modesto . . 570 000 59 Vernalis _ . 154 000 60 Oakdale . _ 327 000 61 822 000 62. lone. _ _ 203,000 675,000 63 Sacramento-San Joaquin Delta Subtotals, Valley Units 6,606,000 2,952,000 28,300 91,100 54,100 6,779:000 APPROXIMATE TOTALS, SAN JOAQUIN RIVER BASIN.. 7,156,000 3,302,000 30,600 103,000 66,900 7,356,000 APPROXIMATE TOTALS, CENTRAL VALLEY AREA 20,100,000 9,308,000 83,600 372 000 301,000 20,860,000 although additional supplies may be needed. The im- portance of providing water for these natural re- sources was recently recognized with the passage by Congress of the Grasslands Water Bill, which will provide water from the Central Valley Project, when available, for flooding about 100,000 acres on the west side of the San Joaquin Valley. The flooded area will be operated as a fall and winter waterfowl concen- tration area. Although the other game species are quite numer- ous, their water requirements are minor in amount. The necessary water supplies are expected to be avail- able from natural sources or small local developments. At the request of the Division of Water Resources, a series of estimates was made by the California De- partment of Fish and Game of the stream flow at certain points in the more important streams of the Central Valley Area which would be required for the protection and maintenance of fish life. The streams were divided into four classes, according to the antici- pated degree of water development for various bene- ficial purposes that might compete with the require- ments for fish. The summer and winter stream flow requirements for fish life in Central Valley Area streams, as estimated by the Department of Fish and Game, are listed in Appendix F. Flood Control. The protection of lowland areas from floods has been a major consideration in the management of water resources in the Central Valley Area. Beginning with the influx of settlers during the period following the discovery of gold, the agricul- tural potential of the vast areas of swamp and over- flow lands was realized, and the construction of low levees to protect individual tracts of land commenced. Competitive development led to extreme difficulties in the control of flood waters, and eventually resulted in governmental supervision and participation in flood control works. Federal participation in flood control works in Cali- fornia first developed in connection with national responsibilities for the improvement of rivers and harbors for navigation. The California Debris Com- mission Act, passed by Congress in 1893, provided that the Commission "mature and adopt plans for the purpose of improving the navigability, deepening 178 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 117 DISTRIBUTION OF MONTHLY WATER DEMANDS, CENTRAL VALLEY AREA (In per cent of seasonal total) Locality and purpose Irrigation demand Sacramento River Diversions, 1941 through 1951 Feather River Diversions, 1941 through 1951 Yuba River Diversions, 1941 through 1951 San Joaquin River Diversions (Fremont Ford- Vernalis) , 1941 through 1951 Merced River Diversions, 1941 through 1951 Tuolumne River Diversions, 1941 through 1951 Stanislaus River Diversions, 1941 through 1951 Visalia to Delano Area, agricultural pumping load, 1947 through 1951 Madera-Merced Area, 1947 through 1951 Fresno Area, 1947 through 1951 ... Coalinga-Los Banos Area, 1947 through 1951 Corcoran-Kern Area, 1947 through 1951. __ Sacramento-Stockton Area, 1947 through 1951 Urban demand Sacramento, 1946 Stockton, 1946 Sonora, 1946 Fresno, 1947 Bakersfield, 1947 January 2.0 0.8 0.9 5.9 2.3 1.9 5.5 4.9 6.7 4.2 4.7 Feb- ruary 1.6 1.2 1.3 7.8 2.8 1.9 5.0 5.1 6.0 4.4 5.1 Marcli 0.5 0.1 0.2 3.7 1.4 2.7 2.2 3.0 2.5 3.1 9.9 5.8 2.6 6.1 5.1 6.7 4.5 6.6 April 7.4 5.0 5.4 12.4 7.1 8.7 9.2 6.5 5.3 6.8 8.1 9.6 4.3 7.8 6.4 6.7 5.8 8.1 May 17.6 18.0 14.9 15.3 13.9 14.6 14.9 8.6 8.8 7.6 6.3 7.8 10.1 9.2 9.5 9.5 10.3 9.9 June 18.7 19.4 16.9 15.3 18.8 17.4 17.5 9.6 12.3 9.8 5.2 8.4 14.2 11.8 10.1 8.7 10.9 10.6 July 20.9 20.7 17.8 21.3 23.3 19.1 19.4 13.3 18.0 17.2 9.0 13.0 17.9 12.8 11.7 12.6 12.2 August 19.7 18.9 17.4 18.3 19.1 19.2 18.5 16.5 20.1 23.0 10.4 17.5 19.3 12.2 13.0 10.7 13.7 12.1 Sep- tember 11.3 12.1 15.0 10.9 12.6 13.3 12.8 16.4 17.5 17.1 10.8 16.8 15.5 10.1 12.3 7.6 12.3 10.8 October 3.9 5.8 12.4 2.8 3.8 5.0 5.5 12.0 8.6 7.5 9.4 8.3 7.2 7.7 9.2 9.6 8.9 8.7 Novem- ber 6.0 3.4 3.8 9.2 4.3 3.1 6.1 7.3 9.8 6.7 5.9 Decem- ber 4.5 1.5 1.9 8.0 2.8 2.0 5.7 5.4 8.8 5.7 5.3 Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 the channels, and protecting the banks of the rivers, and affording relief from flood damages. ' ' Under this act, which had as its primary purpose the regulation of hydraulic mining and the deposition of debris in outflow areas of the tributary streams, reports on plans and projects for navigation, debris control, and flood control were presented to and adopted by Con- gress. The first comprehensive plan for flood control along the Sacramento River was recommended by the Chief of Engineers in 1911, and adopted by Congress as a part of the Flood Control Act of 1917. In 1911 the State of California recognized the interest of the State in the erection, maintenance, and protection of reclamation works on the Sacramento and San Joaquin river systems. The State Reclamation Board, created by the 1911 statute, was authorized to pass upon and approve plans for such reclamation. Since 1917, the State and Federal Governments have had a joint interest in flood control in the Central Valley Area. The flood control acts approved by Congress have provided for local participation in the construction of authorized projects. The 1917 Flood Control Act provided generally that local interests should pay at least one-half of construction costs, furnish rights of way, and maintain the completed project. The 1936 act freed local interests of responsibility for construc- tion costs, but they were required to provide lands, easements, and rights of way, hold the United States free from damages, and maintain and operate com- pleted projects. In 1938 the principle of local con- tribution of rights of way was abandoned by Congress for projects authorized under the 1936 and subse- quent acts. In 1941, however, the federal acquisition of rights of way was limited to those flood control features involving dams and reservoirs, and local interests were required to provide rights of way for channel rectification or improvement. The Sacramento River Flood Control Project is a joint federal-state-local development. The Corps of Engineers, United States Army, presently constructs project works and maintains navigable river channels. The State operates and maintains specified portions of the completed works, other than navigable channels. The remaining works are maintained by reclamation, drainage, or levee districts, or by municipalities. The Legislature, by Chapter 1528, Statutes of 1947, as- sured adequate and proper maintenance of works as- signed such local agencies. This act established the procedure for annual inspection and report of condi- tions of such works, and provided that the State should accomplish the necessary maintenance in case of failure of local agencies to do so, with costs assessed against benefited areas. Construction costs of the CENTRAL VALLEY AREA 179 TABLE 118 ESTIMATED WEIGHTED MEAN IRRIGATION WATER SERVICE AREA EFFICIENCY WITHIN HYDROGRAPHIC UNITS, CENTRAL VALLEY AREA (In per cent) Hydrographic unit Present Probable ultimate Hydrographic unit Present Probable ultimate Reference number Name Reference number Name 1 Sacramento River Basin Mountain Units 45 45 45 45 50 50 50 50 60 50 50 50 60 50 25 60 60 60 60 60 50 40 90 70 65 65 65 65 50 70 50 50 50 50 50 50 60 60 50 75 50 60 60 50 50 75 80 75 80 70 70 75 80 90 85 GO 75 70 31 32 33 34 35 36 37 38 39 40 41 42 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 Tulare Lake Basin Mountain Units West Side, Kern County- Kern River and Tehachapi 50 50 50 50 85 85 90 90 90 70 50 50 50 50 50 50 50 50 70 50 95 80 45 45 45 60 50 40 40 75 50 50 2 Pit River . Tule River. __ 50 3 McCIoud River .. 50 4 Sacramento River above 50 Valley Units 5 West Side, Shasta Dam to 90 C East Side, Cow Creek to Kern 80 85 7 8 9 Red Bluff to Thomes Creek... Antelope to Mud Creek Visalia Fresno-Hanford . 85 80 80 10 11 Butte and Chico Creeks San Joaquin River Basin Mountain Units Mount Diablo _ _ Altamont to San Luis Creek. _ West Side, Los Banos Creek 12 13 14 Yuba and Bear Rivers 50 50 15 16 50 Valley Units Anderson-Cottonwood 50 Chowchilla-Fresno Rivers 50 50 50 17 50 18 Mokelumne-Calaveras Rivers - 50 19 50 20 Valley Units 21 ■>o 70 23. Colusa Trough 90 24 25 Feather River to Butte Slough Yuba West Side, San Joaquin Valley 90 85 26 Merced 80 27 Woodland . Carmichael . . . Dixon . _ _ Yolo 80 28 85 29 65 30 Oakdale . . Stockton 90 85 lone . . 60 Sacramento-San Joaquin Delta 90 Sacramento River Flood Control Project as of 1955 were about $51,000,000 to the United States, and about $85,000,000 to the State of California and to local interests, making a total cost of approximately $136,000,000. In 1945 the State of California, recognizing' the general state interest in the control of floods, estab- lished the State Water Resources Board to formu- late state policy and provide the necesary coopera- tion on federal projects authorized by Congress and adopted by the State Legislature. The State Water Resources Act provided that appropriations would be made by the State to pay for all lands, easements, and rights of way required of local agencies in con- nection with federally authorized flood control proj- ects. The statute also charged local agencies with the responsibility for the operation and maintenance of completed flood control and other works in all cases where the Federal Government requires such local participation. The Sacramento River Flood Control Project, as presently approved, comprises about 450 miles of stream channels and canals, 95 miles of by-passes, and 1,000 miles of levees for the passage of flood flows, and numerous major control works. A comprehensive plan has been adopted for flood control on the San Joaquin River, and several major projects which comprise portions of this plan have already been authorized. Among these are the Little Johns Creek and Calaveras River Stream Groups Project in San Joaquin County, the Merced County Stream Group Project, the Fresno County Stream Group Project, and the project on the Lower San Joaquin River and tributaries. The plan authorized by Congress includes the reservation of a considerable acreage of lowland area for excess flows along the San Joaquin River 180 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA upstream from the mouth of Merced River. Recent development in this region, however, has greatly in- creased land values and costs of acquisition, and modification of the plan is in progress. A flood control reservation of 1,300,000 acre-feet is incorporated in the operating criteria for Shasta Reservoir on the Sacramento River, and a reservation of 400,000 acre-feet is allocated for flood storage in Folsom Reservoir on the American River. In the San Joaquin Valley, eight reservoirs have been built for flood control purposes by the Corps of Engineers, on projects authorized pursuant to the Flood Control Acts of 1936 and 1944, and the companion state legis- lation of 1945. Two of these, Pine Flat Reservoir on the Kings River and Isabella Reservoir on the Kern River, have just been completed. About 500,000 acre- feet of flood control reservation is being provided in Friant and Don Pedro Reservoirs. Hogan Reservoir, on the Calaveras River, has been built by the City of Stockton for the protection of that city from floods. The levee system is not completely coordinated in the San Joaquin River and Tulare Lake Basins, although a general plan for protection has been authorized to which future construction must substantially conform. As of 1950. the Sacramento River Flood Control Project was estimated to provide protection at Sacra- mento against a flood expected to occur not more frequently than once in 25 years, but the completion of Folsom Reservoir should protect against floods expected to occur at intervals of several hundred years. In other parts of the project, the degree of protection afforded varies from once in 15 years to once in 170 years. Future adequate protection would be provided by construction of additional flood con- trol reservoirs, notably Black Butte on Stony Creek, Table Mountain on the Sacramento River, and Oro- ville Reservoir on the Feather River. An alternative to the construction of a dam at Table Mountain is a proposal for the reclamation of Butte Basin by a system of levees and a by-pass channel. Present plans for Oroville Reservoir on the Feather River include a 500,000 acre-foot flood control reservation that will provide a high degree of protection to lands and communities along that stream. The future construction of Success and Terminus Reservoirs on the Tide and Kaweah Rivers, together with the completion of Pine Flat and Isabella Reser- voirs, will provide a substantial degree of flood pro- tection in the Tulare Lake Basin. To attain sub- stantial improvements in the protection from floods in the San Joaquin River Basin, additional construc- tion providing new or increased flood control reserva- tions is needed at Hogan Reservoir on the Calaveras River. .Melones on the Stanislaus, Don Pedro on the Tuolumne, and on Bear Creek in Merced County. Releases of water from multipurpose reservoirs for the control of floods may be substantial in amount. Flood control releases must be given consideration in future plans to meet the water requirements of the areas concerned. The plans must provide for methods of operation of such reservoirs to meet the require- ments of all functions without serious impairment of any. Navigation. Water-borne commerce in the Cen- tral Valley Area is restricted largely to the Sacra- mento River and the delta channels, including the Stockton Deep Water Channel. Substantial invest- ments have been made in ship channels, floating equipment, docks, and storage terminals, and further developments are presently contemplated. Navigable channels may be provided by the installa- tion of low dams across stream channels, with lockage facilities in order to provide passage of vessels. Navi- gable depths may also be provided by the maintenance of stream flow in sufficient quantity. Both methods involve the use of appreciable quantities of water, which may or may not be provided from return flows resulting from other uses of water. Determination of the water supplies necessary for navigation can be made only after definite project proposals have been formulated. No estimates of future water require- ments in the Central Valley Area for navigation were made for the purposes of this bulletin. Salinity Control. Intrusion of saline water from San Francisco Bay has long been a problem in the channels of the Sacramento-San Joaquin Delta. Dur- ing periods of low stream flow and with increased use of fresh water for upstream consumptive uses, the natural fresh-water outflow is not sufficient to repel saline waters. The tides further increase the problem by forcefully propelling saline waters into the by- passes and channels of the Delta. The tidal effects act to impede fresh-water outflow by raising water surface elevations, and by forming a barrier to flow during periods of high tide. The historical method of maintaining the quality of the waters of the Delta for irrigation use involves a continuous flow of fresh water through the channels of the area and into Suisun Bay. It has been variously estimated that to limit the salinity near Antioch to an average content of not more than 100 parts of chloride per 100,000 parts of water, with decreasing salinity upstream, a flow of from 3,300 to 4,500 sec- ond-feet is necessary. Recent measurements are cur- rently being evaluated in an attempt to more precisely define this figure. Proposals have been advanced for a barrier in or below the Delta as a means of con- serving a portion of this water requirement. The Divi- sion of Water Resources has recently conducted an investigation to determine the water requirements and feasibility of these proposals. Hydroelectric Power. The Central Valley Area has by far the greatest amount of developed hydro- electric power in California. The combination of CENTRAL VALLEY AREA 1ST substantial stream runoff and favorable elevations in the Sacramento River Basin lias made possible a more intensive development than in the southern portions of the Central Valley Area. In the San Joaquin and Tulare Lake Basins, however, the greater ranges in elevation, and the resulting greater possible heads, have compensated in a large part for the lesser water supplies in the development of hydroelectric power facilities. These factors will probably continue to ex- ert a similar influence in the future. It is probable that the available water supply of the Central Valley Area will ultimately serve a com- bination of many beneficial uses, certain of which will conflict with use of the water for generation of energy. However, estimates were made of the poten- tial hydroelectric power development under the as- sumption that stream runoff would be used primarily for power production, and with no consideration given to use of the water for other purposes. Table 119 presents data on the present hydroelectric power installations in the Central Valley Area, and on the average seasonal water requirement of the plant with the greatest water demand on a stream system. Table 120 presents estimates of the potential annual power output, installed power capacity, and water demand at the lowest plant on a stream system, under an as- TABLE 119 PRESENT HYDROELECTRIC POWER DEVELOPMENT, CENTRAL VALLEY AREA TABLE 120 EXISTING AND ESTIMATED POTENTIAL HYDROELECTRIC POWER DEVELOPMENT, CENTRAL VALLEY AREA Stream Number of power plants Installed power capacity, in 1,000 kilowatts Present annual water requirement, in acre-feet Sacramento River Basin Pit River 6 2 2 4 10 3 9 4 383 450 5 31 410 44 121 202 1,644,000 5 915 000 Sacramento River . Cow Creek _ . 52,000 196 000 Battle Creek Feather River, 1 766 000 North Fork Yuba River. _. Yuba and Bear Rivers. 454,000 381 000 American River 2 230 000 TOTALS, SACRAMENTO RIVER BASIN 40 6 6 4 3 5 7 1,649 222 78 176 37 29 487 San Joaquin River Basin Mokelumne River 442,000 618 000 Stanislaus River ._ Tuolumne River. 1 340 000 Merced River .. 805 000 Willow Creek 249 000 San Joaquin River. 1,305,000 TOTALS, SAN JOAQUIN RIVER BASIN.... 31 1 3 2 4 1,029 34 7 8 66 Tulare Lake Basin Kings River 103,000 64,000 25 000 Kaweah River.. Tule River .. Kern River _ . 327,000 TOTALS, TULARE LAKE BASIN. 10 115 TOTALS, CENTRAL VALLEY AREA... 81 2,793 Stream Average annual power output. in 1,000,000 kilowatt- hours Installed power capacity, in 1,000 kilowatts Average annual wa ter requirement at lowest plant, in 1,000 acre-feet Sacramento River Basin Sacramento River above Kesvi iek Minor East Side Tributaries Minor West Side Tributaries 5,670 780 260 6,470 3,000 100 3,000 1,180 160 55 1,345 625 20 625 3,450 770 1,110 2,640 1,430 200 American River ..... 1,600 TOTALS, SACRAMENTO RIVER BASIN 19,280 65 1,060 25 1,850 3,240 540 4,510 4,010 15 220 5 385 675 110 940 San Joaquin River Basin 215 450 95 710 Tuolumne River Merced River below Yosemite Park San Joaquin River . _ . 1,150 615 1,080 TOTALS, SAN JOAQUIN RIVER BASIN... 11,290 2,860 90 50 1,210 2,350 595 20 10 250 Tulare Lake Basin 1,020 260 Tule River... 85 440 TOTALS, TULARE LAKE BASIN 4,210 875 TOTALS, CENTRAL VALLEY AREA 34,780 7,235 sumed ultimate development of the water primarily for this purpose. Requirements of a Consumptive Nature Estimates of present and probable ultimate water requirements of a consumptive nature within hydro- graphic units of the Central Valley Area are pre- sented in Table 121. These mean seasonal values rep- resent the amount of water other than precipitation needed to provide for beneficial consumptive use of water on irrigated lands, urban and suburban areas, farm lots, and other water service areas, and for ir- recoverable losses of water incidental to these uses. The estimates were derived from consideration of the heretofore presented estimates of consumptive use of applied water, and of water service area efficiencies of hydrographic units. Table 122 presents estimates of the total water re- quirements for each of the three major basins of the Central Valley Area. This analysis gives considera- tion to the re-use of water in those hydrographic units which are geographically situated so as to enable the rediversion of return now from upstream units. 182 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 121 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL REQUIREMENTS FOR WATER IN HYDROGRAPHIC UNITS, CENTRAL VALLEY AREA (In acre-feet) Hydrographic unit Refer- ence number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16. 17. 18. 19 20 21. 22. 23. 24. 25. 26. 27. 28. 29 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 12 43. 44. I.", 16 17. 48. I'.i .Ml 51. 52 53 :,i :,.-, i6 57 - 59 mi * i l 62 63 Name Sacramento River Basin Mountain Units Goose Lake Pit River McCloud River Sacramento River above Shasta Dam West Side, Shasta Dam to Cottonwood Creek East Side, Cow Creek to Paynes Creek Red Bluff to Thomes Creek__ Antelope to Mud Creek Stony Creek Butte and Chico Creeks Cortina Creek Feather River Yuba and Bear Rivers Cache Creek American River Putah Creek Valley Units Anderson-Cottonwood Tehama Vina Orland Chico Arbuckle Colusa Trough Feather River to Butte Slough Yuba Marysville-Sheridan Woodland Carmichael Dixon Yolo Irrigated lands Present Tulare Lake Basin Mountain Units West Side, Kern County Kern River and Tehachapi Mountains Tule River Kaweah River Kings River Valley Units Antelope Plain Kern Earlimart Visalia Fresno-Hanf ord Tulare Lake ._ San Joaquin River Basin Mountain Units Mount Diablo Altamont to San Luis Creek. . West Side, Los Banos Creek to Avenal Creek San Joaquin River Chowchilla-Fresno Rivers \ breed River Tuolumne River Stanislaus River Mokelumne-Calaveras Rivera . Cosumnes River Valley Units Antioch Delta-Mendota West Side, San Joaquin Valley . Madera Merced. .. Loa Banos Modesto Vei nalis Oakdale. Stockton _ lone mi mo San Joaquin I (elta 24,000 241,000 6,200 5,300 4,800 16,400 3,200 2,200 3,300 177,000 84,000 27,800 58,700 9,400 160,000 51,300 57,300 132,000 151,000 69,800 1,434,000 729,000 111,000 203,000 248,000 159,000 70,600 232,000 47,600 7,000 600 4,600 64,800 ,127,000 337,000 582,000 ,617,000 365,000 4,000 12,400 2,000 2,800 4,600 4,200 6,000 800 147,000 49,000 596,000 396,000 885,000 891,000 876,000 190,000 578,000 803,000 22,000 826,000 Probable ultimate 79,400 569,000 52,000 26,000 108,000 288,000 157,000 25,600 126,000 29,700 134,000 481,000 432,000 158,000 223,000 94,400 83,400 196,000 135,000 303,000 204,000 225,000 1 ,574,000 676,000 159,000 413,000 401 ,000 571.000 303,000 559,000 40,000 700,000 96,400 52,800 52,400 937,000 2,389,000 832,000 861,000 2,204,000 006,000 31,800 123,000 165,000 24,600 92, 100 127,000 108,000 87,800 198,000 143,000 180,000 137,000 1,686,000 892,000 1,016,000 726,000 654,000 235,000 356,000 929,(100 336,000 742,000 Farm lots Present 100 1,300 1,200 300 200 600 300 700 500 1,300 800 900 4,000 2,200 800 1,400 1,500 1 ,600 1,200 1,200 200 3,700 10,400 3,400 5,400 14,700 3,800 1,200 600 7,800 3,900 5,800 3,000 6,300 1,100 2,500 5,400 1,300 6,100 Probable ultimate 300 4,200 300 100 500 1,100 500 100 600 200 500 3,000 1,800 1,000 1,400 400 400 1,300 1,200 1,700 2,300 1,400 5,800 3,000 1,200 2,400 2,100 2,800 2,400 2,000 200 2,400 400 200 100 7,600 15,000 6,300 6,700 17,200 3,900 200 400 700 300 400 500 300 1,100 800 1,300 1,000 11,400 6,200 6,100 4,100 6,300 1,200 3,600 6,900 2,000 6,400 Urban and suburban areas Present 1,100 600 800 200 600 500 7,700 2,500 600 2,700 200 4,000 1,600 1,200 1.000 4,500 600 2,000 1,600 2,500 2,200 4,800 57,600 2,400 400 400 200 1,200 33,800 3,400 14,800 54,600 800 200 800 400 600 600 5,200 200 0,600 7,400 2,200 10,000 500 3,200 24,400 200 1,400 Probable ultimate 500 7,000 2,500 3,600 1,000 3,600 1,300 200 1,300 2,600 1,300 16,000 14,400 4,800 15,400 1,000 9,800 6,200 5,000 3,900 15,100 1,500 5,200 5,000 0,200 8,600 9,100 144,000 5,300 1,200 300 4,700 1,000 500 300 8,400 68,000 9,500 30,000 107,000 4,500 300 800 1,300 200 500 2,100 7,000 2,600 4,400 4,600 35,400 1,400 14,300 9,900 14,600 7,600 22,100 1,700 8,300 57,800 ..•,209 7,000 Other water service areas Present 1,000 100 200 100 600 300 200 300 100 3,500 1,900 200 800 700 44,200 13,500 700 2,000 100 400 200 100 400 1,400 700 500 200 2,200 700 700 900 600 100 3,600 21,500 100 Probable ultimate 14,000 500 600 800 1,200 900 600 1.000 200 200 12,400 15,100 1,000 4,600 400 700 116,000 38,500 1,400 2,000 100 300 1,800 500 500 1,000 16,400 700 100 400 800 1,300 500 4,300 1,200 1,600 1,600 1,000 5,000 15,000 34,100 100 Approximate totals Present 24,100 244,000 6,900 6,300 5,100 17,600 300 3,400 2,500 3,900 189,000 89,300 28,800 62,800 9,600 164,000 53,600 59,000 134,000 157,000 71,300 1,484,000 746,000 1 15,000 207,000 254,000 220,000 74,200 234,000 48,600 7,400 700 5,000 99,709 1,173,000 344,000 602,000 1,687,000 370,000 4,000 12,900 2,200 5,200 6,100 5,300 7,500 2,000 153,000 50,200 004,000 407.000 902,000 918,000 892,000 192,000 584,000 833,000 23,500 834,000 CENTRAL VALLEY AREA 183 TABLE 122 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL REQUIREMENTS FOR WATER IN MAJOR BASINS, CENTRAL VALLEY AREA (In acre-feet) Basin Present Probable ultimate 3,819,000 4,280,000 5,093,000 7,720,000 8,657,000 San Joaquin River (including Delta) 7,648,000 APPROXIMATE TOTALS. CEN- TRAL VALLEY AREA 13,190,000 24,030,000 It may be noted that because of this re-use of water tlic requirements shown in this table do not represent the sum of the requirements of the individual hydro- graphic units contained in the respective basins. Ra- ther, the table indicates the depletion in the total water supply of the respective basins caused by de- velopment and use of the water. is evident that in such cases the present subsurface inflow cannot be considered a permanent water sup- ply. The estimates of present supplemental water requirement for this bulletin, therefore, were ad- justed accordingly. In the areas in which as the result of prior investi- gations an overdraft is known to exist, the use of ground water generally has intensified since the date of the studies. On the other hand, since the time that some of the earlier investigations were made, the Friant-Kern Canal has been supplying water to a portion of the San Joaquin Valley, in the varying amounts shown in Table 123. In many instances the distribution systems are still in the process of con- struction in the irrigation districts concerned. Where the facilities permit, a portion of the Friant-Kern water has been applied to lands for the specific pur- pose of recharging ground water basins. Specific data regarding the amount of such water usage are not available, and for the purpose of estimating present supplemental requirements it was assumed that these works were not in operation. Supplemental Requirements In general, the present supplemental water require- ment in each hydrographic unit of the Central Val- ley Area was taken as equivalent to the estimated "round water overdraft, when such was known to exist. The difference between estimated present and probable ultimate water requirements for each hydro graphic unit plus the present supplemental require- ment was taken as the measure of the probable ultimate supplemental water requirement, except for adjustments made necessary by reason of supplies of supplemental water expected to be delivered through the Friant-Kern and Madera Canals. Results of prior studies of the use of ground water in the Central Valley Area indicated that overdrafts exist in ground water basins of the Tehama, Arbuckle, Yuba, Marysville-Sheridan, Carmichael, Antelope Plain, Kern, Earlimart, Visalia, Fresno-Hanford, Tulare Lake, Delta-Mend ota, West Side San Joaquin Valley, Madera, Stockton, and lone Hydrographic Units. In many of the ground water basins where progressive lowering of the water table now occurs, the indicated present overdraft is less than the esti- mated present supplemental water requirement shown in Table 124. This results from the excessive lowering of ground water levels which has occurred in the basins concerned, and which has induced a greater than normal subsurface inflow of water from adja- cent areas. The future import of supplemental water to the areas will result in gradual accretion to the ground water underlying the lands served. In the course of time, the existing hydraulic gradients will tend to approach stabilization at lessened slopes, or the slopes may even become reversed in direction. It TABLE 123 SEASONAL WATER DELIVERIES IN SAN JOAQUIN RIVER AND TULARE LAKE BASINS THROUGH FRIANT-KERN CANAL (In acre-feet) .Month October November December January February March April May June July August September TOTALS Season 1948-49 1,300 1,300 500 16,400 22,700 3,000 45,200 1949-50 15,200 22,400 17,800 52,900 45.000 41.500 100 195,000 1950-51 23,500 37.400 1 1 ,800 65,900 108,000 86,100 35,800 368,000 1951-52 14,400 8,800 4,700 2,800 12,100 28,900 55.700 126,000 138,000 69,900 401,000 1952-53 73,000 17,500 200 1,100 56,400 54,200 40,100 99,300 64,000 60,000 74,600 740,000 1953-54 22,500 7,400 1 1 .900 52,800 58,000 124,000 153,000 172,000 140.0C0 63,000 811,000 Present supplemental water requirements for valley hydrographic units in the Tulare Lake Basin were estimated by inflow-outflow studies, using available water supply and utilization data. The use of water in remaining hydrographic units, where no defi- ciencies are known to exist, is primarily by stream diversion, or by ground water pumpage without ap- parent overdraft. In the determination of ultimate supplemental water requirements, the water supplied through the Friant-Kern Canal from Friant Reservoir was allo- cated to hydrographic units on the basis of modifica- tion of the existing contracts, with the total deliverv 1S4 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA of water equal to the estimated safe yield of Friant Reservoir. This allocation is set forth in the following tabulation : Estimated ultimate supplemental Hydrographic unit seasonal water Refer- supply from F riant ence Reservoir, in number Name acre-feet 37 Kern 459,000 38 Earlimart 512,000 39 Visalia 227,000 40 Fresno-Hanford 6,100 Madera 418,000 TOTAL 1,622,000 It should be pointed out that estimated ultimate surface water supplies available to the Antioch, Mo- desto, Stockton, and lone Hydrographic Units are less than the total probable developed water supplies in the tributary watersheds by the amount of exporta- tions to the San Francisco Bay Area. These exporta- tions of water are made through the Contra Costa Canal, the Mokelumne Aqueduct of the East Bay Municipal Utility District, and the Hetch Hetchy Aqueduct of the San Francisco Public Utilities Com- mission. These systems, under conditions of presently planned development, will export 195,000 acre-feet, •224,000 acre-feet, and 448,000 acre-feet of water per year, respectively, from the Central Valley Area. In determining ultimate supplemental water re- quirements, consideration was given to the recovery of return flow from an upstream or mountain hydro- graphic unit by a downstream or valley unit. Supple- mental water available for re-use by a downstream unit was evaluated by applying appropriate factors to the amount of applied water required by the up- TABLE 124 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL WATER REQUIREMENTS IN HYDROGRAPHIC UNITS, CENTRAL VALLEY AREA (In acre-feet) Hydrographic unit Present Probable ultimate Hydrographic unit Present Reference number Name Reference number Name Probable ultimate 1 Sacramento River Basin Mountain Units 3,000 9,300 15,000 70,000 27,000 56,100 350,000 48,400 24,000 105,000 276,000 160,000 23,100 127,000 28,800 136.000 323,000 374,000 136,000 181,000 86,600 153,000 82,000 175,000 65,000 166,000 217,000 68,000 287,000 158,000 527,000 237,000 328,000 31 32 33 34 35 36 37 38 39 40 41 43 44 45 46 47. 48 49 50 51 52 53 54 55 56.. 57 58 59 60 61 62 63.. Tulare Lake Basin Mountain Units West Side, Kern County Kern River and Tehachapi 11.800 215,000 211.000 158,000 91,100 184,000 20,200 524,000 133,000 103,000 10,000 40,800 2 Pit River 3 McCloud River 660,000 4 Sacramento River above Shasta Dam Tule River 90,900 53,300 5 West Side, Shasta Dam to 48,800 Valley Units 6 East Side, Cow Creek to Paynes Creek - . ... 895,000 7 Red Bluff to Thomes Creek . . Antelope to Mud Creek Stonv Creek,. 1,530,000 8 715,000 9 454,000 10 Butte and Chico Creeks Cortina Creek 733,000 11 428,000 12 Feather River _____ San Joaquin River Basin Mountain Units Mount Diablo 13 14 Yuba and Bear Rivers Cache Creek _ 15 American River. _ 16. Putah Creek, _ __ __ 32,400 Valley Units Anderson-Cottonwood Tehama _ Altamont to San Luis Creek __ West Side, Los Banos Creek 125,000 164,000 17 San Joaquin River .. 13,200 18 Chowchilla- Fresno Rivers Merced River_ 91 500 19 Vina _ 129,000 111,000 87 000 20 Orland. ___ _ _ 21 Chico 22 Arbuckle. Mokelumne-Calaveras Rivers . 1 98 000 23 Colusa Trough. _ _. 147 000 24 25 Feather River to Butte Slough. Yuba Valley Units 26 Marysville-Sheridan.. . 64 000 27 Woodland 109 000 28 Carmiehael ... West Side, San Joaquin Valley. 1,632,000 639 000 29 Dixon. . __ 30 Yolo 150,000 Los Banos . Vernalis _ 46,000 Oakdale _ 264,000 lone 326,000 Sacramento-San Joaquin Delta CENTRAL VALLEY AREA 185 stream unit but not beneficially used in that unit. The summation of the supplemental water require- ments in all hydrographie units deriving their water supply from the same stream basin, less the supple- mental return flow available for re-use within the basin, was taken to be the supplemental water re- quirement for the stream basin as a whole. Table 124 presents estimates of present and prob- able ultimate mean seasonal supplemental water re- quirements of hydrographie units of the Central Val- ley Area. Table 125 gives estimated basin supple- mental requirements after consideration of re-use of return flow. TABLE 125 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL WATER REQUIREMENTS IN MAJOR BASINS, CENTRAL VALLEY AREA (In acre-feel) Basin Present Probable ultimate 124,000 871,000 790,000 4,157,000 4,044,000 3,539,000 APPROXIMATE TOTALS, CEN- TRAL VALLEY AREA 1,785,000 11,740,000 Courtesy State Division of Highways CHAPTER VIM LAHONTAN AREA The Lahontan Area lies along the California- JsTevada border between latitudes 35° 30' and 42° N., and consists of those lands generally easterly from the drainage divide of the Sierra Nevada, and the Tehachapi, San Gabriel, and San Bernardino Moun- tains, including the drainage basins of Death Valley and the Mojave River. The area is designated Area 6 on Plate 8, and includes the Counties of Mono and Inyo, as well as parts of Modoc, Lassen, Sierra, Nevada, Placer, El Dorado, Alpine, Kern, Los An- geles, and San Bernardino Counties. Although por- tions of most drainage basins of the Lahontan Area lie in Nevada, tabulations in this bulletin are limited to the areas within the State of California. Among the principal cities and urban communities are Lancas- ter, Palmdale, Mojave, Barstow, Victorville, Bishop, Bridgeport, Truckee, and Susanville. Tn order to facilitate the present studies, the La- hontan Area was subdivided into 12 hydrographic units, the boundaries of which lie on the watershed divides of the principal streams or interior drainage basins, as shown on Plate 8. Table 126 lists the 12 hydrographic units and their areas, and Table 127 presents the areas of the portion of each county in- cluded within the Lahontan Area. The water surface area of Lake Tahoe, which lies in Hydrographic Unit 4 and in the Counties of Placer and El Dorado, is not included in the tabulations. TABLE 126 AREAS OF HYDROGRAPHIC UNITS, LAHONTAN AREA Hydrographic unit ' Reference number Name Acres 1 505,000 2 3 Madeline Plains 486,000 1,499,000 4___ Truckee River . _ . 428,000* 287,000 6 7 8 Walker River . . Mono Lake 582,000 438,000 188,000 9 _ Owens River . . 2,005,000 10 Death Valley . 9,868,000 11 Mojave River . 3,140,000 12 1,546,000 APPROXIMATE TOTAL . 20,970,000 TABLE 127 AREAS OF COUNTIES WITHIN BOUND- ARIES OF LAHONTAN AREA ( Jourity Acres 305,000 109,000* 6,486,000 1,624,000 2.116,000 723,000 468,000 2,009,000 Nevada . _ ... 114,000 120,000* San Bernardino _. . . .. 6,761,000 138,000 APPROXIMATE TOTAL 20,970.000 Does mil include water surface area of Lake Tahoe. * Does not include water surface area of Lake Tahoe. The climate of the Lahontan Area varies as widely as its topography, which ranges from the lofty rugged crags along the Sierra Nevada crest to the plateaus of Madeline Plains, the deeply incised Owens Valley, and the arid expanse of the Mojave Desert. Mount Whitney and Death Valley, within 90 miles of each other, are the highest and lowest spots in the United States, emphasizing the contrast common to this area. The highest temperature recorded in the United States was 134° P. at Greenland Ranch in Death Valley in July, 1913. Winter temperatures below 0° F. are common in the Sierra Nevada and the northern valleys and plateaus. The mean seasonal depth of precipitation varies from a maximum of about 50 inches in the high elevations of the Sierra Nevada to 1.7 inches or possibly less in portions of the desert regions. Snowfall is characteristic of the mountains and high plateaus and valleys during win- ter. Generally, some 75 per cent of seasonal precipi- tation occurs from November through April. Although precipitation in the desert is light, local thunder- storms have been known to contribute much more than the equivalent of average seasonal precipitation to local areas in less than two hours. The estimated mean seasonal natural runoff of streams in the Lahontan Area is about 3,177,000 acre- feet, or about 4.5 per cent of that for the entire state. The principal streams are the Susan, Truckee, Carson, Walker, and Owens Rivers, draining the easterly slopes of the Sierra Nevada, and the Mojave (187) 188 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA River, draining the northeasterly slopes of the San Bernardino Mountains. Streams in the desert por- tions of the area are ephemeral in nature. A substan- tial amount of the runoff from the Sierra Nevada is derived from snowmelt of late spring and early summer. A relatively small amount of water is imported to the Lahontan Area and stored in Tule Reservoir, located in the Madeline Plains Hydrographie Unit. This water comes from Cedar Creek, a tributary of the Pit River in the Central Valley Area, and is used for irrigation of grain and as a water supply for waterfowl ponding areas operated by the California Department of Fish and Game. Reservoir storage records indicate an average seasonal import of about 11,000 acre-feet. An average of some 7,000 acre-feet of water has been exported from the Lahontan Area seasonally since about 1870 from the Little Truckee River, for irrigation use in Sierra A^alley in the Cen- tral Valley Area. Also, about 2,000 acre-feet of water are diverted seasonally from Echo Lake in the Truckee River Hydrographie Unit, for hydroelectric power generation in the American River Basin of the Central Valley Area. The major export of water from the Lahontan Area is that which is carried by the Los Angeles Aqueduct to the South Coastal Area. The City of Los Angeles diverts water in the Mono Lake Hydrographie Unit and transports it by tunnel to the headwaters of the Owens River. The Los Angeles Aqueduct, diverting waters of both the Mono Lake and Owens River Hy- drographie Units, then conveys the waters by conduit some 233 miles to the City of Los Angeles, where it is distributed and used. The capacity of the aqueduct, about 320,000 acre-feet seasonally, presently limits this export from the Lahontan Area. As shown on Plate 4, a total of 58 valley fill areas, which may or may not contain usable ground water, has been identified in the Lahontan Area. Only those in the Owens, Antelope, Mojave, and Indian Wells Valleys have been extensively developed by wells, the water being used principally for irrigation. Thirty- eight of the foregoing valley fill areas each cover more than 100 square miles. Population in the Lahontan Area is characteristi- cally sparse and widely scattered, and cities and urban communities are relatively small. However, population growth during recent years has generally kept pace with the phenomenal rates experienced in other parts of the State. The most notable recent in- creases in permanent population have occurred in and around Barstow and Lancaster in the southerly I '"il ion of the area. In these localities the advent of major military and related aircraft industrial instal- lations has produced an influx of resident civilians. who either assist in operation of the installations or are employed in business ventures catering to the de- mands of the increased military and civilian popula- tion. In addition to the foregoing, there has been a large increase in seasonal population of the recrea- tional areas in the vicinity of Lake Tahoe, and in the Owens Valley and Mono Basin. This increase has been far greater proportionately than the increase in per- manent residents in these predominantly recreational localities. Table 128 shows the increase in population of four representative urban communities from 1940 to 1950, as well as three representative unincorpo- rated urban centers. Many of the more important urban centers in the area are unincorporated and without definite boundaries. TABLE 128 POPULATION OF PRINCIPAL URBAN CENTERS, LAHONTAN AREA 1940 1950 City Within city limits In suburbs Total Within city limits In suburbs Total Barstow 2,100 1,600 1,500 2,000 3,600 1,500 2,100 5,200 3,000 2,000 2.100 1,200 700 6,100 5,300 2,900 3,200 4,300 1,700 2,800 10,400 7,000 5,700 Victorville . 3,200 3,600 2,100 1,000 * Unincorporated areas. Agriculture is the major economic activity of the Lahontan Area, and the raising of livestock predomi- nates. In the mountain valleys where surface diver- sion of water proved to be practicable, as well as in other valley areas where ground water supplies were found to be available, the lands have been developed to irrigated agriculture. However, since about 1920 the aggregate irrigated acreage has remained sub- stantially unchanged. In the high valley irrigation developments, which are characteristic of the north- ern portion of the Lahontan Area, the majority of the irrigated lands has been devoted to pasture-type crops. Field crops have prevailed where irrigation water is available along the Mojave River and in Antelope Valley. The water supply development of the Lahontan Area has been closely allied to the demands of irri- gation. Early settlers diverted the flow of surface streams to water their forage crops. Diversions from the Mojave River were first recorded in 1872, and this was followed by accelerated activities of land development companies and promotional agencies in the area. Apart from such surface diversions, a supply of ground water was developed in lower LAHONTAN AREA 189 Antelope Valley around 1880, from flowing' wells which were drilled to depths of between 200 and 500 feet. The introduction of electric power to Antelope Valley in 1914 resulted in a major increase in the use of ground water for irrigation. The rate of pumping has accelerated to this date, with attendant severe lowering of ground water levels. The fertile lands of the Owens Valley were first developed by settlers in the late 1860 's. By 1910 some 50,000 acres were under irrigation, almost exclusively from surface water sources, the principal crops being alfalfa, pasture, and decidous fruits. An artesian well was drilled at Keeler in 1902, but because of a large content of hydrogen sulphide the water was not used for domestic purposes. Several other artesian wells were drilled in the vicinity during the next few years, with unsatisfactory results. Other than the water ob- tained from small domestic and stockwatering wells, ground water received little attention in the valley for many years, due to the ample surface supplies readily available. By 1907 the growth of the City of Los Angeles made search for an additional water supply imperative. As a result, the city undertook construction of the then unprecedented Los Angeles Aqueduct, and by 1913 had started acquiring and conveying to its service area in the South Coastal Area a major portion of the available water supplies in the Owens Valley. Development of the waters of the Mono Basin by the City of Los Angeles was com- pleted in 1940. These large exports have virtually eliminated irrigated agriculture in the economy of the Owens Valley and Mono Basin. During the drought years of the early 1930 's the city drilled a number of wells in the extensive ground water basins underlying the Owens Valley, and for a few years pumped a substantial amount of water for export from that source. Commencing in the latter decades of the last cen- tury, the waters of the Truckee, Carson, and Walker Rivers have been developed to create an important agricultural and stockraising economy in both Cali- fornia and Nevada. Among the larger of such irriga- tion developments within California are those along the East and West Walker Rivers. As has been stated, in this century there has been little change in the total irrigated acreage in the Lahontan Area. Increases in irrigated agriculture in the southerly portion, comprising Antelope and Mo- jave Valleys, have been counterbalanced by marked decreases in the Owens Valley and Mono Basin, re- sulting from the cited export by the City of Los Angeles. The 82 reservoirs presently constructed in the La- hontan Area have an aggregate storage capacity of some 1,400,000 acre-feet, of which over 700,000 acre- feet are provided by the high-level storage in Lake Tahoe. The principal reservoirs are listed below. Storage Hydrographic capacity, in Reservoir Stream unit acre-feet Tule Lake__. ..Cedar Creek Madeline Plains 39,500 McCoy Flat- Susan River Honey Lake 17,300 Lake Tahoe_ Truckee River Truckee River 732,000 Boca .Little Truckee Rivet Truckee River 41,200 Donner Donner Creek Truckee River 11,000 Independence. Independence Creek . Truckee River 18,500 Topaz West Walker River Walker River- 59,000 Bridgeport- _ -East Walker River- Walker River 42,000 < Irani Lake- Hush Creek Mono Lake. 47,500 Long Valley _ Owens River Owens River 184,000 Tinemaha ( (wens River ( >wens River 16,600 Ha i wee ( >wens River Owens River 60,000 Reservoirs in the Truckee River Basin, and Topaz and Bridgeport Reservoirs on the Walker, are largely used to conserve and regulate irrigation water sup- plies for lands in both California and Nevada. The reservoirs in the Truckee River Hydrographic Unit are operated coordinately for irrigation, hydroelectric power generation, and municipal uses. The last four reservoirs listed in the tabulation provide regulation for a municipal water supply for the City of Los An- geles. This water is also utilized for power develop- ment along the route of the aqueduct to terminal storage in the San Fernando Valley of the South Coastal Area. In addition to the principal reservoirs listed in the foregoing tabulation, there are a number of small storage developments in the Lahontan Area. Several in the Mono Lake and Owens River Hydro- graphic Units are essentially for the purpose of regu- lation of water for hydroelectric power generation. Most of the remaining small reservoirs serve to regu- late irrigation water supplies. The lack of adequate firm water supplies has limited expansion of the irrigated acreage in the Lahontan Area. It is probable, however, that in the future addi- tional diversified irrigated crops will be produced, particularly in the Mojave River and Antelope Val- leys, utilizing water expected to be imported into those areas. In addition, there will probably be fur- ther development of local water supplies in the north- erly portion of the area, and attendant increase in irrigated agriculture. Present urban centers depend- ent upon agriculture will expand, and new urban centers will come into being to supply services and materials in the vicinity of the new agricultural de- velopments. Urban centers supported largely by mili- tary or industrial installations may also experience growth in the future. A compilation of the principal water service agencies in the Lahontan Area, together with the number of domestic services and irrigated acres served by each agency, is included in Ap- pendix B. Outstanding scenic attractions and a climate favor- able to winter and summer sports activity have com- bined to make relatively large portions of the La- hontan Area extremely attractive to vacationists, sportsmen, and tourists. The lands around Lake Tahoe ,'■■ - . . ' ■' ■ m Scene Near Susanville JJBrtS*r-.«-i m ^'HWfr-Uf MRIF!t^^f%HH||^ Courtesy Eastman's Studio The Sierra Nevada 'S+rJiitFT : Courtesy State Division of Highways LAHONTAN AREA ] 2.0 0.9 0.6 0.4 0.4 0.6 1.8 1.8 2.6 2.6 2.6 1.8 9 Owens River . 1.4 1.6 1.5 1.4 0.6 0.4 0.4 0.6 2.0 2.0 1.9 2.0 1.8 10 Death Valley.- _._ 1.6 0.4 2.0 1.5 11 Mojave River 1.3 12 Antelope Valley 1.5 0.6 2.1 1.4 Use of Water in Other Water Service Areas Unit values of water use on the miscellany of service areas grouped in this category were derived generally from measured or estimated present deliv- eries of water to the typical development involved. In most cases the estimates were made in terms of per capita use of water, and the actual acreage of the service area was not a significant factor. In such cases the aggregate amount of water deliveries is relatively very small, and negligible recovery of return flow is involved. For purposes of study, therefore, the esti- mated unit values of delivery of water to these facili- ties were considered to be also the measures of con- sumptive use of applied water. Both the National Forest and Park Services pro- vided estimates of present and probable ultimate unit deliveries of water to all facilities within their juris- diction. The estimates were generally in terms of per 8—99801 capita use of water, and were based on actual meas- urements and experience. They varied widely from place to place and in type of use, and for this reason arc not detailed herein. The total quantity of water used for migratory waterfowl was determined from data furnished by the United States Fish and Wildlife Service, and by those private organizations which operate areas used to feed or attract birds. Unit values of water use were not obtained. The individual operations vary considerably, depending upon the water supply and whether the land is cultivated for crop growth. For other water service areas not encompassed by the foregoing specific types of water service, unit values of consumptive use of applied water under probable ultimate conditions of development were assigned on a per capita basis. In such areas, sparse residential, industrial, and recreational development 198 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 139 ESTIMATED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY AND CONSUMPTIVE USE OF WATER ON URBAN AND SUBURBAN AREAS, LAHONTAN AREA (In feet of depth) Hydrographic unit Refer- ence num- ber 1_ 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Name Present ( ; ross delivery Surprise Valley. Madeline Plains Honey Lake Truckee River.. Carson River Walker River. _ Mono Lake Adobe Valley Owens River Deatli Valley Mojave River. _. Antelope Valley . 1.0 0.9 1.2 0.4 1.0 1.9 1.5 1.5 1.9 0.6 2.3 2.0 Con- sump- tive use of applied water 0.5 0.5 0.6 0.2 0.5 1.0 0.8 0.8 0.9 0.3 1.2 1.0 Probable ultimate Gross delivery 0.4 2.2 2.2 2.2 2.2 2.8 3.6 3.6 3.6 Con- sump- tive use of applied water 1.1 1.1 1.4 0.2 1.1 1.1 1.1 1.1 1.4 1.8 1.8 1.8 is expected in the fixture. For areas outside national forests, monuments, and military reservations, it was estimated that the ultimate population density will average about eight persons per square mile, and that per capita consumptive use of water will be about 70 gallons per day. In areas inside national forests, mon- uments, and military reservations the same per capita use estimates were made, but the population density was assumed to average about four persons per square mile. The period of water use was assumed to be of only three months' duration during the summer for areas above 3,000 feet in elevation, while water service for areas below 3,000 feet in elevation was assumed to be throughout the year. CONSUMPTIVE USE OF WATER In general, estimates of the amounts of water con- sumptively used in the Lahontan Area were derived by applying appropriate unit values of water use to the service areas involved. The estimates represent the seasonal amount of consumptive use of water under mean conditions of water supply and climate. Table 140 presents estimates of present consumptive use of applied water and precipitation in areas having water service, and Table 141 presents corresponding estimates for probable ultimate conditions of develop- ment. FACTORS OF WATER DEMAND Certain factors relating to water requirements, other than the amount of water consumptively used in a given service area, such as necessary rates, times, and places of delivery, quality, losses, and other perti- nent requirements, must be considered in planning water development projects. The most important of these demand factors in the Lahontan Area are those concerned with irrigation development. Those factors related to the water supply for urban, suburban, recreational, and other uses are of secondary im- portance. The demand factors of principal importance to planning for water resource development of the Lahontan Area are discussed in the following sections. Monthly Distribution of Water Demands The demand for irrigation water in the Lahontan Area varies from little or none during the winter months to more than 20 per cent of the seasonal total during dry summer months. Available information indicates that the irrigation water demands in the Truckee and Carson River Basins are heavily concen- trated in the late spring and summer months. In the TABLE 140 ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF WATER ON PRESENT WATER SERVICE AREAS, LAHONTAN AREA (In acre-feet) Refer- ence number 1 2 3 4 5 6 7. 8. 9. 10. 11. 12. Hydrographic unit Name Surprise Valley Madeline Plains Honey Lake Truckee River Carson River Walker River Mono Lake Adobe Valley Owens River Death Valley Mojave River Antelope Valley APPROXIMATE TOTALS Irrigated lands Applied water Precipitation 61,600 12,000 65,400 3,200 11,000 30,300 2,800 3,300 18,200 25,000 31,400 200,000 464,000 35,800 7,100 40,300 1,600 8,900 18,500 1,900 1,900 6,000 4,100 5,300 41,300 173,000 Farm lots Applied water 200 100 200 negligible 100 100 negligible negligible 100 100 100 400 1,400 Urban and suburban areas Applied water 200 negligible 1,200 600 negligible negligible negligible 700 300 2,000 1,100 6,100 Other water service areas Applied water 200 7,400 300 100 100 negligible 500 4,300 500 700 14,100 Approximate total consumptive use of applied water 62,000 12.300 74,200 4,100 11,100 30,500 2,900 3,300 19,500 29,700 34,000 202,000 486,000 LAHONTAN AREA 199 TABLE 141 PROBABLE MEAN SEASONAL CONSUMPTIVE USE OF WATER ON ULTIMATE WATER SERVICE AREAS, LAHONTAN AREA (In acre-feet) Refer- ence number 1 2 3 4 5 6 7 8 9 10 11 12 1 1\ drographie unit Name Surprise Valley Madeline Plains Honey Lake Truckee River Carson River Walker River - Mono Lake Adobe Valley Owens River Death Valley Mojave River Antelope Valley. APPROXIMATE TOTALS Irrigated lands Applied water Precipitation 1 28,000 198,000 360,000 31,200 15,000 47,000 14,700 24,400 205,000 ,840,000 947,000 ,339,000 5,151,000 78,000 127,000 229,000 22,300 I 1,600 34,300 11,100 18,200 82,000 335,000 109,000 353,000 1.473,000 Farm lots Applied water 1,000 1,600 2,600 300 200 400 200 300 1 ,600 10,500 5,200 4,300 28,200 Urban and suburban Applied w ;iPi 1,100 1 .600 5,200 3,700 200 500 200 300 3,000 17,200 8,900 11,800 53,700 Other water service areas Applied water 100 12,300 24,200 400 600 300 200 1,100 20,900 3,400 1,300 64,800 Approximate total consumptive use of applied water 130,000 214,000 392,000 35,600 16,600 48,800 15,300 25,000 211,000 I.SS9.000 965,000 1,356,000 5,298,000 Antelope Valley and Mojave River Hydrographic Units the irrigation demand is more uniform through- out the season, with appreciable use of water even in the winter months. Urban water demands vary from four to six per cent of the annual total during the months of December through March, to over ten per ccnl from June through September. Representative data on monthly distribution of irrigation and urban water demands in the Lahontan Area are presented in Table 142. Irrigation Water Service Area Efficiency In order to determine the irrigation water require- ments of the Lahontan Area, it was desirable to esti- mate the over-all efficiency of irrigation practice in the various service areas. Irrigation water service area efficiency was measured by the ratio of consump- tive use of applied irrigation water to the gross amount of irrigation water delivered to a service area. Present irrigation water service area efficiencies were estimated after consideration of geologic conditions of the serv- ice areas involved, their topographic position in rela- tion to sources of water supply and to other service areas, consumptive use of water, irrigation practice, and usable return now. Irrigation practice was de- termined from records of water diverted in the Sur- prise Valley, study of present practice in the Carson River Basin, and studies of the Antelope Valley where water not consumptively used returns to ground water storage. Additional factors affecting the esti- mates of probable ultimate irrigation water service area efficiencies were related to the location and extent of presently undeveloped irrigable lands, as well as the increased cost of developing water. For purposes of illustration, the weighted mean values of all irriga- tion water service area efficiencies within each hydro- graphic unit of the Lahontan Area are presented in Table 143. TABLE 142 DISTRIBUTION OF MONTHLY WATER DEMANDS, LAHONTAN AREA (In per cent of seasonal total) Locality and purpose January Feb- ruary March April May June July August Sep- tember October Novem- ber Decem- ber Total Irrigation demand Truckee River and Carson River Hydrographic Units (Newlands Project, 1909 through 1917) Antelope Valley and Mojave River 2.0 5.6 5.0 2.0 4.8 5.0 2.1 5.0 4.5 0.0 13.6 6.0 5.0 7.0 20.1 9.0 7.1 9.0 18.7 12.0 10.0 11.0 18.9 14.0 11.9 12.0 13.4 16.0 15.3 12.0 9.7 13.0 14.1 11.0 2.7 11.0 9.9 9.0 0.8 6.0 6.8 7.0 4.0 5.0 6.0 100.0 100 Urban demand SusanviUe, 1948 through 1952 Antelope Valley and Mojave River 100.0 100.0 1 Based on the average agricultural electric power use. 2 Based on the average domestic deliveries by water utilities. 200 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 143 ESTIMATED WEIGHTED MEAN IRRIGATION WATER SERV- ICE AREA EFFICIENCY WITHIN HYDROGRAPHIC UNITS, LAHONTAN AREA (In per cent) Hydrographic unit Present Probable ultimate Reference number Name 1 60 50 50 50 30 50 50 50 50 70 70 90 60 2 50 3 70 4 50 5 50 6 70 7 50 8 90 9 70 10 Death Vallev 80 11 80 12 90 WATER REQUIREMENTS Water requirement, as the term is used in this bul- letin, refers to the amount of water needed to pro- vide for all beneficial uses of water and for irre- coverable losses incidental to such uses. Water re- quirements of the Lahontan Area that are primarily nonconsumptive in nature are discussed in general terms in the ensuing section. Following this, water requirements of the area that are consumptive in character are evaluated for both present and probable ultimate conditions of development. Requirements of a Nonconsumptive Nature The principal water requirements of a nonconsump- tive nature in the Lahontan Area are associated with the preservation and propagation of fish and wild- life, and the generation of hydroelectric power. Other requirements of lesser importance are those for min- ing, timber, and industry. For the most part, such requirements for water are extremely difficult to evaluate other than in conjunction with definite plans for water resource development. Their consideration in this bulletin, therefore, is limited to discussion of their implications as related to planning for future development of water resources. Fish and Wildlife. The Lahontan Area, excluding the arid desert region in the southern portion, em- bodies a large number of excellent trout fishing streams and lakes. The principal game fish is the rainbow trout, which is found in most streams and lakes, but other species of trout also provide consid- erable angling opportunities. Cutthroat trout are taken primarily in the Walker and Carson Rivers and in Crowley Lake. Eastern brook and brown trout are well distributed, the Truckee and Owens Rivers being the two greatest producers of brown trout. Lake trout (Mackinaw) and kokanee red salmon are found in Lake Tahoe and Donner Lake. Many of the higher lakes and streams, particularly in the southerly Sierra Nevada, contain golden trout. Eagle Lake, in Lassen County, has a unique fishery for the Eagle Lake rainbow trout, as this fish is not found elsewhere. Although the southern and southeastern arid portions of the Lahontan Area contribute very little to the fishery values, some of the streams which flow north- ward from the San Bernardino Mountains have pop- ulations of rainbow trout which offer sport fishing. Warmwater game fishes, including the black basses, sunfish.es, crappies, and catfishes, are present in the Lahontan Area, but the amount of angling for these fishes is light compared to that expended in pursuit of trout. The warmwater game fishes have been stocked in various small reservoirs and farm ponds, and largemouth black bass are also found in the Owens River. At the request of the Division of Water Resources, a series of estimates was made by the California De- partment of Fish and Game of the stream flow at certain points required for the protection and main- tenance of fish life in each of the important streams of the Lahontan Area. These streams were divided into four classes by the Division, according to the anticipated degree of development for various pur- poses that would compete with recreational or com- mercial fishing requirements. These classes are de- scribed, and the summer and winter water require- ments for fish life, as determined by the Department of Fish and Game, are listed in Appendix F. The California Department of Fish and Game op- erates two migratory waterfowl management areas in the Lahontan Area, namely Madeline Plains and Honey Lake. There are also several private gun clubs, which have as their primary purpose the hunting of migratory waterfowl. Many of these areas are also cultivated, and their water requirements are included in the requirements for water on agricultural lands. No satisfactory means were devised for predicting an increase or decrease of private gun clubs, and it was assumed that the water requirements for such use, other than where combined with agricultural use, would be very minor in nature. Hydroelectric Power. Estimates of the amount of hydroelectric power potentially obtainable from streams in the Lahontan Area under average condi- tions of complete development, together with the non- consumptive water requirements for this purpose, are shown in Table 144. The power output was estimated on the assumption that stream runoff will be used primarily for power production. That is, no considera- tion was given in the estimates to use of the water for other beneficial purposes. It is probable, however, that the streams ultimately will serve a combination of beneficial uses. Accordingly, the actual hydro- electric power output under such combined opera- LAHONTAN AREA 201 TABLE 144 EXISTING AND ESTIMATED POTENTIAL HYDROELECTRIC POWER DEVELOPMENT, LAHONTAN AREA Stream basin Average annual power output, in 1,000,000 kilowatt- hours Installed power capacity, in kilowatts Average annual water requirement at lowest plant, in 1,000 acre-feet Truckee River, in California Carson River, in California- Walker River, in California 75 120 140 105 735 15,000 25,000 30,000 25,000 190,000 325 200 230 90 Owens River 305 Subtotals . Los Angeles Aqueduct _ 1,175 270 285,000 105,000 1.150 305* TOTALS 1,445 390,000 1.150 Existing power plants and plants 931 279,000 * Owens River water. tions would be reduced from the estimates presented herein. The greater part of the runoff of the Lahontan Area occurs in many small, steep streams originating in the high snow fields of the Sierra Nevada at eleva- tions above 10,000 feet, and terminating on the inte- rior plateau at elevations of from 4,000 to 6,000 feet. While the streams are of only limited size, the topog- raphy is favorable to many small hydroelectric power developments. The estimated potential installed hy- droelectric power capacity of the area is about 390,000 kilowatts, while existing plants and those under con- struction have an installed capacity of nearly 280,000 kilowatts. Except for the South Coastal Area, where the small amount of hydroelectric power available is now nearly all developed, the Lahontan Area leads the State in the proportion of present development, which is about two-thirds of its estimated potential. Mining. A small amount of mining is carried on at the present time in the Lahontan Area, and the necessary water for its production is minor in amount. A major portion of the water used for this purpose can be made available for re-use after treatment for removal of acid wastes in order to maintain suitable water quality. Timber. Commercial timber production in the Lahontan Area is minor in extent, and the water requirements for this purpose are relatively small. Most of the water used in production is available for re-use after being returned to stream channels. This condition is expected to be maintained under probable ultimate conditions. Requirements of a Consumptive Nature Estimates of present and probable ultimate water requirements of a consumptive nature within hydro- graphic units of the Lahontan Area are presented in Table 145. These mean seasonal values represent the amount of water other than precipitation needed to provide for beneficial consumptive use of water on irrigated lands, urban and suburban areas, farm lots, and other water service areas, and for irrecover- able losses of water incidental to these uses. The esti- mates were derived from consideration of the hereto- fore presented estimates of consumptive use of applied water, and of water service area efficiencies of hydro- graphic units. The water requirements for migratory waterfowl management areas have been estimated by the Cali- fornia Department of Fish and Game and the United TABLE 145 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL REQUIREMENTS FOR WATER, LAHONTAN AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Appro tot ximate als Name Refer- ence number Present Probable ultimate Present Probable ultimate Present Probable ultimate 1'resent Probable ultimate Present Probable ultimate 1 2 Surprise Valley _ . . 102,000 24,000 131,000 6,300 36,700 60,600 5,600 6,700 36,500 35,700 44,800 222,000 214,000 397.000 515,000 (12,400 31,200 68,000 29,400 27,100 292,000 2,300,000 1,183,000 1,488,000 400 200 400 200 200 200 200 200 800 2,000 3,200 5,200 600 400 800 400 600 3.200 21,000 10,400 8,600 400 2,400 1,200 1,400 600 4,000 2,200 2,200 3,200 10,400 7,400 400 1,000 400 600 6,000 34,400 17,800 23,600 200 7,400 300 100 100 500 4,300 500 700 100 12,300 24,200 400 600 300 200 1,100 20,900 3,400 1,300 103,000 24,400 141,000 7,800 36,900 60,900 5,700 6,700 38,600 40,800 49,500 226,000 218,000 416,000 3 555.000 4 5. Truckee River 70.800 32.600 6- 70.100 7 8 Mono Lake - _ 30.400 28,300 9 10 Owens River Death Valley 302,000 2,376,000 11 12 Mojave River . Antelope Valley- _ . - APPROXIMATE TOTALS. . 1,215,000 1,521,000 712,000 6,607,000 3,000 56,000 12,000 107.000 14.000 65,000 741,000 6,835,000 202 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA States Fish and Wildlife Service. Following is a sum- mary of data as of September, 1952, secured from these agencies, concerning- present and estimated ultimate water requirements for this use. Applied water, in acre-feet per season Area inundated, in acres Present (1952) 3,500 Probable ultimate 10,500 8,200 46,700 These requirements are included in Table 145 under the heading of "Other Water Service Areas." Supplemental Requirements The present supplemental water requirement in each hydrographic unit of the Lahontan Area was taken as equivalent to the estimated deficiency in sur- faee water supply development, plus the estimated ground Avater overdraft when such was known to exist. The difference between estimated present and probable ultimate water requirements for each hydro- graphic unit, plus the present supplemental require- ment, was taken as the measure of the probable ulti- mate supplemental water requirement. In the Lahontan Area the present deficiencies in surface water supply development are of considerable significance to the agricultural economy of the area. In those places, particularly in northerly portions of the area, where the lands are largely irrigated by diversion from streams, late summer and fall stream flows are frequently too small to meet the optimum requirements of crops on developed lands. This en- forced undesirable irrigation practice, resulting in most cases from underdevelopment of regulatory storage capacity on the stream systems, adversely affects agricultural crop returns of the area. There- fore, estimates of the amounts of supplemental water necessary in the Lahontan Area to meet the optimum requirements of lands presently irrigated from sur- face water sources were included in the estimates of supplemental water requirements. Unlike the Lahon- tan Area, in most of the other major hydrographic areas of the State any present deficiencies in surface water supply development are of relatively minor significance to the general economy of the areas, and, for this reason, were not considered in estimating supplemental water requirements. Results of prior studies of the use of ground water in the Lahontan Area indicate that an overdraft ex- ists at present only in the Antelope Valley Hydro- graphic Unit. It is known that the use of ground water in that unit has been intensified substantially since last studied by the Division of Water Resources in 1946, and it is probable that the overdraft has in- creased proportionately. However, lacking specific knowledge of the amount of such increase in ground water use, the estimates of water supply as developed in 1946 were used in this bulletin. Table 146 presents the estimates of present and probable ultimate mean seasonal supplemental water requirements of the hydrographic units of the La- hontan Area. TABLE 146 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL WATER REQUIREMENTS, LAHONTAN AREA (In acre-feet) Hydrographic unit Present Probable ultimate Reference number Name 1 2 3 Surprise Vallev. . . Madeline Plains. 25,000 11,000 60,000 7,000 16,000 160,000 140,000 403,000 474,000 4 5 Truckee River . 63,000 2,700 6 25,200 7 24,700 8 9 10 Adobe Valley . . Owens River _ . Death Valley 21,600 263,000 2,335,000 11 1,166,000 12. 1,455,000 APPROXIMATE TOTALS. 279,000 6,373,000 CHAPTER IX COLORADO DESERT AREA The Colorado Desert Area comprises the south- eastern portion of California between latitudes 32.5° and 35.5° N., and consists of lands draining directly into the Colorado River and centrally drained desert basins without outlet, such as the basin draining to the Salton Sea. It is bounded on the north by the watershed of the Mojave River, on the south by the international boundary with Mexico, and on the west by the San Bernardino Mountains and the San Ja- cinto and Peninsular Ranges. The Colorado River and the Nevada state line bound the area on the east. The area is designated Area 7 on Plate 8, and includes all of Imperial County as well as portions of San Diego, Riverside, and San Bernardino Counties. The Col- orado Desert Area encompasses a range in elevation from about 235 feet below sea level at Salton Sea to over 11.400 feet above sea level in the San Bernardino Mountains. Among the principal incorporated cities are Banning, Palm Springs, Indio, Brawley, El Centro. Blythe, and Needles. The lands of the Colorado Desert Area having rights in and to the waters of the Colorado River were excluded from the presentations in this chapter dealing with conditions of probable ultimate develop- ment. Under their established rights these lands have a large imported water supply available, sufficient in quantity to meet their requirements under conditions of probable ultimate development. In general, the lands are highly developed to irrigated agriculture at the present time, and plans have been made for their complete development. In most instances the existing canals and appurtenant water supply works have been constructed with sufficient capacity to serve water to meet the ultimate needs of the lands. Since one of the principal purposes of this bulletin is to determine the ultimate supplemental water requirements which will have to be provided for under The California Water Plan, the lands of the Colorado Desert Area which are already completely planned for were ex- cluded from consideration in this respect, The bound- aries of the lands in the Colorado Desert Area having rights in and to the waters of the Colorado River are shown on sheets 25 and 26 of Plate 9. In order to facilitate the present studies, the Colo- rado Desert Area was divided into six hydrographic units, the boundaries of which lie on the watershed divides of the principal streams or enclose a geographi- cally similar area, as shown on Plate 8. Table 147 presents the six hydrographic units and their areas, as well as the area having rights in and to the waters of the Colorado River. Table 148 similarly presents TABLE 147 AREAS OF HYDROGRAPHIC UNITS, COLORADO DESERT AREA Hydrographic unit Reference number Name \i-ic ■ 1 2 3 Twentynine Palms Coachella Valley 3,867,000 1,087,000 1,898.000 4 5 6 Imperial Valley 113,000 2,095,000 2,035,000 APPROXIMATE SUBTOTAL Areas having rights in and to the waters of the Colorado River APPROXIMATE TOTAL - 11,100,000 1,321,000 12,420,000 1 TABLE 148 AREAS OF COUNTIES WITHIN BOUND- ARIES OF COLORADO DESERT AREA County Acres 1,658,000 3,138,000 5,494,000 805,000 11,100,000 Areas having rights in and to the waters of the Colorado River 1.321,000 APPROXIMATE TOTAL. _ 12,420.000 the areas of the portion of each county included within the Colorado Desert Area. The arid climate of the Colorado Desert Area is characterized by short, mild winters and exceptionally hot, dry summers. The greatest rainfall in the area is in the higher elevations of the Peninsular Range and the San Bernardino Mountains. The mean sea- sonal depth of precipitation at Raywood Flats in the San Bernardino Mountains is 37.8 inches, part of which mav occur in the form of snow. Seasonal pre- cipitation' in the valley areas averages 3.6 inches m depth at Indio, 3.2 inches at El Centro, 4.0 inches at Blythe and 4.8 inches at Needles. The greater portion of 'the 'rainfall in the valley areas is from localized thunder storms, resulting in extreme variability m ( 203 ) Date Gardens Near Indio Sgtfyk '* ij> . - -* 47* *it \J"J j..^ . .-».., Courtesy Spence Air Photos Coachella Branch of All-Amerian Canal Courtesy State Division of Highways fc - ■*'■ \«A COLORADO DESERT AREA 21).") distribution of precipitation. At several stations within the area no precipitation has been recorded for entire seasons. The rainfall on valley and mesa lands is generally so minor in amount that it has little prac- tical significance to the water resources of the area. The estimated mean seasonal natural runoff of streams in the Colorado Desert Area is about 221,000 acre-feet, or about 0.3 per cent of that for the entire State. For purposes of this bulletin the flow in the Colorado River was not included in this estimate. Somewhat less than one-half of the runoff occurs in the centrally drained basins. This runoff is not ordi- narily available for surface diversion due to variability in time and amount of its occurrence. The estimated mean seasonal natural runoff of the Whitewater River and its tributaries is approximately 61,800 acre-feet, or about 28 per cent of the total runoff of the area, and forms an important part of the water supply of the Coaehella Valley. A few streams that originate in the higher elevations of the Peninsular Range flow perennially in portions of their headwater channels, but the flow quickly seeps and evaporates upon reach- ing - the valley floor. During the occasional periods of extreme rainfall, surface stream flow reaches the Salton Sea. Torrential floods of short duration, caused by the characteristic cloudburst type of rainfall dis- tribution, may occur at any place within the area. The Salton Sea, about 345 square miles in area at an elevation of 235 feet below sea level, has a present mineral content slightly greater than that of sea water, precluding its use for domestic or irrigation purposes. As shown in Plate 4, a total of 45 valley fill areas, which may or may not contain usable ground water, has been identified in the Colorado Desert Area. Only two basins, underlying Coaehella and Borrego Valleys, are appreciably developed for water supply purposes. Ground water is pumped from these two basins and used for domestic and irrigation purposes in the valleys. Little information is available concern- ing most of the other 43 valley fill areas, as they have not been subject to extensive development. Population in the Colorado Desert Area, with the exception of urban and recreational areas in the Coaehella Valley, has not kept pace with the large over-all growth which has occurred in other portions of the State. Urban developments are for the most part adjuncts to the agricultural activity, which has not changed greatly in areal extent in the decade from 1940 to 1950. Population in the several desert resort areas more than doubled in the 1940-1950 period. Table 149 presents the data on population in eight of the principal urban communities from 1940 to 1950. It should be noted that population in resort areas such as Palm Springs, Desert Hot Springs, and Twentynine Palms is subject to seasonal variation. The economy of the Colorado Desert Area is based upon agricultural development in the Imperial, Coa- TABLE 149 POPULATION OF PRINCIPAL URBAN CENTERS, COLORADO DESERT AREA 1940 1950 City Within city limits In suburbs Total Within city limits In suburbs Total El Centra __ 10,000 11,700 3,900 2,300 3,400 5,400 2,400 3,600 1,000 700 1,200 600 600 11,000 12,400 3,900 3,500 3,400 6,000 3,000 3.600 12,600 11,900 7.000 5,300 7,700 6,400 4,100 4,100 3,000 1,500 2,100 2,700 1,800 15 600 Brawley 13 400 Banning . . 9 100 Indio 8 000 Palm Springs 7,700 6,400 5 900 Ely the .. Needles 4,100 chella, and Palo Verde Valleys, and the Yuma Project. The mild winter climate and consequently practically year-round growing season, combined with ground water development in localized areas and importation of Colorado River water for irrigation, have per- mitted the expansion of specialty produce, such as off-season truck crops, citrus, dates, cotton, and table grapes. Irrigation in the Imperial Valley was first con- ceived about 1860, but did not commence until the last decade of the 19th century. The Colorado River Irrigation Company was formed in 1892, and surveys and plans were made to divert water from the Colo- rado River north of the international boundary, and convey it to the Alamo River by a canal through Mexico. The water would flow through the Alamo River channel to the Imperial Valley, where distribu- tion of the imported supply would be made. The original company failed to secure adequate financing-, and the California Development Company was formed in 1896, with its subsidiary, La Sociedad de Riego y Terrenos de la Baja California, S. A., formed in 1898. Construction of works by these companies between 1900 and 1902 made possible the delivery of water to Mexico and to the Imperial Valley in 1901. Difficul- ties were encountered in maintaining an adequate flow of water in the canal and river channel, and the companies petitioned the Mexican Government for permission to divert 10,000 second-feet below the in- ternational boundary. Under authority of the Mexi- can Government, two dredger cuts were made in the banks of the Colorado River below the international boundary in 1905. Control gates were not installed at the cuts, as they had not then been approved by the Mexican Government. In the winter of 1905 the Colorado River reached an unprecedented stage and breached the lower dredge cut, the uncontrolled flow reaching the Salton Sea through the New and Alamo Rivers, which were eroded to their present depths at that time. Closure of the break and confinement of the Colorado River to its channel required six at- tempts and three years to complete. Legal difficulties Courtesy Blythe Phofo Shop Diversion From Colorado River for Palo Verde Irrigation District COLORADO DESERT AREA 207 beset the California Development Company, and judg- ments for damages resulting from the flow of Colo- rado River water through the dredge cut were in- curred, forcing receivership of the company in 1909. The company operated under a receivership from 1909 until 1916, during which time major development of the Imperial Valley occurred. The Imperial Irrigation District, which in 1950 comprised almost 894,000 acres in the Imperial Valley, was formed in 1911, and in 1916 purchased the irrigation system, including the properties of the California Development Company and its subsidiary, the Compania de Terrenos y Aguas de la Baja California, S. A. Imported water supplies were delivered to Imperial Valley through the Mexican canal system until 1942, when the All- American Canal, heading at Imperial Dam on the Colorado River, commenced operation. The Imperial Irrigation District assumed operation of the All- American Canal system on May 1, 1952. The Main All-American Canal, constructed by the United States Bureau of Reclamation, has a capacity of 10,000 second-feet at the point above Drop 1 where the canal divides into two branches. The branch to the Coachella Valley has an initial capacity of 2,500 second-feet at the turnout, which is gradually re- duced to 1,500 second-feet at the northern end of the East Mesa area of the Imperial Irrigation District. The Imperial Irrigation District has capacity to re- ceive water at the rate of 7,500 second-feet through the continuation of the Main Branch of the All- American Canal. This branch supplies all of the dis- trict with the exception of that portion of the East Mesa supplied by the Coachella Branch. The Coachella Valley, comprising the northern por- tion of the Salton Basin, has developed for the most part since 1900. Prior to 1900, the Southern Pacific Company received alternate sections of the public lands in consideration for the construction of a rail- road through the valley, completed in 1879. Remain- ing lands, other than Indian reservations, were ac- quired in 1885 and 1886 by private parties, under the provisions of the Desert Land Act. In 1894 the Southern Pacific Company drilled a deep well at Mecca, developing an abundant supply of good quality artesian water. This discovery stimulated interest in agricultural development, but the excessive cost of the then available methods of well drilling forestalled extensive development until 1900, at which time im- proved methods of drilling became economical. Wells were drilled throughout the southern portion of the valley, and by 1907 over 400 wells existed between Indio and the Salton Sea, of which about 300 were artesian. Early farms were located close to the Salton Sea, but many of these have since been abandoned due to salinity resulting from poor drainage in the fine-textured soils in the lower portion of the Coa- ehella Valley. The northward movement of agriculture away from the artesian area was made possible by im- provement of pumping equipment. Agricultural development in the Coachella Valley was limited by an insufficient local water supply for full development of irrigable lands. In 1918 the Coachella Valley County Water District was organ- ized to protect the existing water supply development and to secure an imported supplemental water supply from the Colorado River. The district assumed con- trol of the Coachella Valley Storm Water District in 1937. The Coachella Valley County Water District now includes about 268,000 acres, of which about 136,000 acres are within the service area of the All- American Canal. In 1934, the district entered into a contract with the United States Bureau of Reclama- tion for the construction of facilities for importation of Colorado River water to Coachella Valley, resulting in the construction of the Coachella Branch of the All-American Canal. The canal conveys Colorado River water along the east side of Coachella Valley, crosses the valley just north of the City of Indio, and turns southerly along the west side of the valley. Flood detention basins have been built on the up- stream side of the canal in order to protect the canal and to provide flood protection for developed lands. Delivery of water to most of the developed lands is accomplished by an underground distribution system. Water rights for lands in Palo Verde Valley, lying along the right bank of the Colorado River in the vicinity of Blythe, date from 1877 when Thomas H. Blythe filed for the water necessary for the irrigation of 40,000 acres. Little development occurred until 1904, when the water rights were transferred to the Palo Verde Land and Water Company. The rights were subsequently assigned to the Palo Verde Mutual Water Company in 1908. The agricultural develop- ment of the valley was given impetus by the comple- tion of the first railroad connection in 1915. The present water service agency is the Palo Verde Irriga- tion District, which included about 104,000 acres within its boundaries in 1950. The irrigation water distribution system was purchased by the district in 1923. The original headgate works for gravity diver- sion of Colorado River water to the canal system were located near the northeast corner of the valley. The regimen of the Colorado River was changed after Parker Dam and Headgate Rock Dam were con- structed, and in 1945 the construction of a temporary rock weir across the Colorado River immediately up- stream from the old headgate works was necessary. The diversion canal was extended to a point upstream from the rock weir to permit continued gravity diver- sion of irrigation supplies. The Yuma Project, a United States Bureau of Reclamation irrigation development, was authorized in 1904, and is located in California and Arizona on both sides of the Colorado River. The California por- 208 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA t ion of the project, the Reservation Division, consists of the Bard and Indian Units. The portion of the project in California, previously served by a canal from Laguna Dam, is now served by the All-Ameri- can Canal. It embraces about 15,000 acres, 8,000 of which are allotted to Indians. The remaining 7,000 acres, which constitute the Bard Irrigation District, are allotted to non-Indian operators. The Colorado Desert Area has taken its place in recent years as one of the nation's outstanding resort areas. Resorts are principally located in and adjacent to Palm Springs, Desert Hot Springs, and Twenty- nine Palms. The development of "dude ranch" re- sorts and other desert types of recreational facilities has attracted thousands of seasonal visitors. While the principal resort season occurs during the winter months, there is an appreciable year-round influx of tourists and visitors to the area. Iron ore production in California was relatively small until 1942, when heavy demands were placed on the State's iron deposits by the Kaiser Steel Company blast furnaces and steel plant at Fontana. This plant secures its ore from the Eagle Mountains deposit lo- cated about 40 miles east of Indio, the only current California source of ore for pig iron. Scattered mining operations in the Colorado Desert Area also produce gold, silver, manganese, lead, pumice, copper, gypsum, and sand and gravel. The two military establishments of present im- portance to the economy of the Colorado Desert Area are the El Centro Naval Air Station and the Salton Sea Experimental Station. In summary, it should be emphasized that water is employed in the Colorado Desert Area primarily for the production of agricultural crops, and to a much smaller extent for mining and for municipal purposes including domestic and industrial. Insofar as is known, no water is now utilized in the area for the generation of hydroelectric power, except as a by- product of water diverted through the All-American Canal, nor for navigation excepting to a very minor extent for recreation on the lower Colorado River, nor is it foreseen that there will ever be appreciable requirements of such nature. Flood control structures have been constructed on the Whitewater River north of the Salton Sea. A system of levees extending through both Mexico and California was constructed early in the 20th century to prevent a recurrence of the break-through of the Colorado River to the Salton Sea. The construction of Hoover Dam in 1935 greatly reduced the threat of floods on the lower Colorado River. The present consumptive use of water for recreation is limited to water consumed for domestic purposes in resort and recreational areas. There follows in this chapter a presentation of available data and estimates pertinent to the nature and extent of water utilization and requirement in the Colorado Desert Area, both at the present time and under probable conditions of ultimate develop- ment. The presentation does not include data and estimates for the ultimate service areas in the Palo Verde Irrigation District, the Yuma Project, and the All-American Canal Project. These projects are cov- ered, and their aggregate service area determined, by the Boulder Canyon Project Act and related docu- ments, including appropriative water rights and con- tracts between the operating agencies and the Secre- tary of the Interior for delivery of water to meet their supplemental requirements from the Colorado River. In view of these facts and for the purpose of this bulletin, the named areas constitute a special entity whose water supply and requirements need not be considered in detail in connection with The California Water Plan. Consideration of those areas in this bulletin was limited to present conditions. The data and estimates for ultimate conditions presented in this chapter apply only to those parts of the Colo- rado Desert Area outside the Boulder Canyon Project service area. PRESENT WATER SERVICE AREAS As a necessary step in estimating the amount of the water requirement in the Colorado Desert Area, with the present pattern of land use and under mean conditions of water supply and climate, determina- tions were made of the location, nature, and extent of presently irrigated and urban and suburban water service areas. Remaining lands were not classified in detail with regard to their relatively minor miscella- neous types of water service, although such water service was given consideration in estimating the present water requirement. Irrigated Lands It was determined that under present conditions of development in the Colorado Desert Area, about 565,000 acres are irrigated in a given year, on the average. This constitutes approximately eight per cent of the land irrigated throughout California. Irrigated grain and hay, alfalfa, and truck crops are dominant in acreage in the Colorado Desert Area. In the Coachella Valley the principal crops are dates, early grapes, citrus, and winter truck crops such as tomatoes, corn, squash, and string beans. Approxi- mately 90 per cent of all domestic dates marketed in the United States are grown here. The largest acre- ages of irrigated crops in the agricultural areas along the Colorado River and in the Imperial Valley are alfalfa, cotton, flax, sugar beets, truck, and grain. The principal winter truck crops in the Imperial Valley are lettuce, carrots, tomatoes, peas, and melons. Cropping practices in the Colorado Desert Area are somewhat different than in other areas of the State in that the growing seasons are long, tempera- tures are extremely high in midsummer, and all water COLORADO DENKUT AREA •JO! I used in crop production is provided through irriga- tion. Much of the land will produce three truck crops in two years, or produce one crop of truck and one of cotton or sugar beets in the same year. Interplanting of dates and citrus is common practice. Alfalfa land in the Imperial Valley commonly yields six cuttings per year, even though the crop is held dormant during a portion of the summer mouths. The field surveys upon which determinations of irrigated acreage in the Colorado Desert Area were based were accomplished during the period from 1948 through 1951, by several agencies with varying stand- ards and degrees of accuracy. Information regarding the dates of field mapping and sources of data is contained in Appendix D. Based on the available survey data, the irrigated lands were classified into various crop groups, with a view to segregating those of similar water use. As a result of the double-crop- ping that prevails in the area and the longer growing seasons, the area of each crop produced annually is necessarily approximate. A list of the various crop groups into which irrigated lands of the Colorado Desert Area were classified follows: Alfalfa Hay, seed, and pasture Pasture Grasses and legumes, other than alfalfa, used for livestock forage Orchard .-Deciduous fruit and nuts Citrus Oranges, lemons, grapefruit, and tangerines Dates Vineyard Principally Thompson seedless grapes Truck crops ..Intensively cultivated fresh veg- etables, including lettuce, car- rots, tomatoes, peas, beans, onions, squash, melons, and sweet corn Cotton Sugar beets Hay and grain Barley, wheat, and oats Miscellaneous field crops __Milo, sesbania, hemp, flax, saf- flower, corn, and beans. It is estimated that approximately 8,000 acres in the Colorado Desert Area are occupied by farm lots at the present time. These consist of farm buildings and the immediately adjacent yards and gardens re- ceiving water service. Summaries of presently irrigated acreages within the Colorado Desert Area, by the various crop groups, are presented in Tables 150 and 151. Table 150 lists the acreages by liydrographic units, and Table 151 by counties. Urban and Suburban Water Service Areas It was determined that under present conditions of development in the Colorado Desert Area approxi- mately 14,000 acres are devoted to urban and sub- urban types of land use. For the most part, the busi- ness, commercial, and industrial establishments and surrounding homes included in this areal classification receive a municipal type of water supply, although some industries and many of the suburban homes have individual pump and pressure water supply sys- tems. Areas of urban and suburban water service within each liydrographic unit of the Colorado Desert Area are listed in Table 152, and within each county in Table 153. It should be noted that areas shown are gross acreages, as they include streets and inter- mingled undeveloped lands that are a part of the urban type of community. Unclassified Areas Remaining lands in the Colorado Desert Area, other than those that are irrigated or urban and sub- urban in character, were not classified in detail as regards present water service. Less than 10,000 acres of a total of about 12,300,000 acres of such remaining lands actually receive water service at the present TABLE 150 AREAS OF PRESENTLY IRRIGATED LANDS WITHIN HYDROGRAPHIC UNITS, COLORADO DESERT AREA (In acres) Hydrographic unit Alfalfa Pas- ture Or- chard Citrus Dates Vine- yard Truck crops Sugar beets Cotton Hay and grain Mis- cel- la- neous field crops Net irri- gated area Farm lots In- cluded non- water service areas Ap- Refer- ence number Name proxi- mate gross area 1 3 Tvventvnine Palms .. Coachella Valley . 1,600 2,400 500 168,000 30,800 400 1,500 100 2,700 3,500 1,400 100 2,500 1,900 100 5,700 100 200 100 7,100 1,400 1,500 4,100 100 63,700 10,100 34,100 4,100 27,900 1,700 400 89,000 10.900 700 300 77,900 6,500 2,000 30,200 2,500 467,000 63,700 negli- gible 700 100 4,500 2,1,00 negli- gible 900 100 11.400 1,500 2,000 31,800 2,700 4 483,000 5 e Colorado River _ Lanfair Valley. . APPROXIMATE TOTALS 67,800 203,000 8,200 1,500 4,500 6,100 10.000 78,000 34,100 34,000 Kill, 85,400 565,000 7,900 13,900 587,000 210 WATER UTILIZATION AND REQUIREMENTS OP CALIFORNIA < o < o I o u z ID o z _ 2 CO = Q Z < < Qi z LLI LU Ct Q- < LU < o o o c > o O +3 « <£ o o o c o otqqt- © CN ©" CN C- 1-' CI O 00 «U "Si • * ooic ) o O O 3 c o CO CN Vp - i CI nclu onw serv are -TcnJ; co" 0> 1-1 hH C C © ° 2. c > o B CO O O o c > O "*- w "a "" i 03 03 O ■* co .- l~" fc~ M CD c ■a o o o c > o c c © c > o © "*"! ©. ,r I ©. a; cd cu CD* *o" CN O r W3 h- CO CO tn W ■* io ■ >-< c o © c o © c c o « o 2 a rc 00 V ■*. f: "0 lO T-H -^ o .3 ia r-< t~" .- o > >. o o o c o o o c © CD CO b- t- cS ■o CO" Q o o c c o c o o - O US •o +^> cm' cn' ■* O ■g o o c c o o c o ca 1-1 ■*- ■°. cj O c o o c o o o © c o iq CN Tt *- CM M CO «=j" oo" ca C^ o o o c o ca © c c © o ©_ cn cc ie o_ "3 OS CN r- 1 co" 5 CO CO o CN CO J . H d e c a. Colorado River .... _. 24,900 6 Lanfair Valley APPROXIMATE TOTALS.. 185.000 181,000 14,600 14,400 10,500 2,500 40.900 68.400 800 3,600 95,000 43,000 475,000 COLORADO DESERT AREA 213 TABLE 157 OTHER WATER SERVICE AREAS UNDER PROBABLE ULTIMATE CONDITIONS, COLORADO DESERT AREA (Excluding lands having rights in and to the waters of the Colorado River) (In acres) Hydrographic unit Inside national forests, monu- ments, and military reservations Outside national forests, monu- ments, and military reservations Reference number Name Above 3,000-foot elevation Below 3,000-foot elevation Above 3,000-foot elevation Below 3,000-foot elevation Approximate total 1 306,000 248,000 5,500 319,000 48,600 677,000 182.000 313,000 12,200 419,000 2,396,000 558,000 1,493,000 101,000 2,053,000 1,399,000 3,698,000 l,037,0CO 1,811.000 101,000 2,065,000 1,818.000 2 3 4 5 6 APPROXIMATE TOTALS 559,000 368,000 1,603,000 8,000,000 10,530,000 such encroachment for the purposes of the present studies, nor to determine what portion will be on irrigable lands. The estimate of probable ultimate urban and suburban water service areas is included in Table 158, and the areas shown are gross acreages, including streets, vacancies, etc. Other Water Service Areas Remaining lands of the Colorado Desert Area, not classified as irrigable or urban and suburban under conditions of ultimate development, aggregate about 10,530,000 acres, or 95 per cent of the area. This does not consider lands having rights in and to the waters of the Colorado River. As previously mentioned, it was assumed that ultimately these other water service areas will be served with water in amounts sufficient for their needs. No attempt was made to segregate these "other water service areas" in detail in regard to the nature of their probable ultimate water service. However, as shown in Table 157, they were broken down for convenience in estimating water require- ments into those portions inside and outside of na- tional forests, monuments, and military reservations, and above and below an elevation of 3,000 feet. The lands classified as ' ' other water service areas ' ' include recreational developments both public and private, military establishments, residential and industrial types of land use outside of urban communities, etc. By far the greater portion of the lands are situated below 3,000 feet in elevation, and are characterized by rough topography interspersed with undrained, alluvial-filled basins. It is expected that even under conditions of ultimate development much of this large area will be sparsely settled, and will have very minor requirements for water service. Summary Table 158 comprises a summary of probable ulti- mate water service areas, segregated into irrigable, urban and suburban areas, and other water service areas, and excluding lands having rights in and to the waters of the Colorado River. TABLE 158 SUMMARY OF PROBABLE ULTIMATE WATER SERVICE AREAS, COLORADO DESERT AREA (Excluding lands having rights in and to the waters of the Colorado River) (In acres) Hydrographic unit Irrigable lands Urban and suburban areas Other water service areas Refer- ence num- ber Name Approxi- mate total 1 2 3 Twentynine Palms _ _ Coachella Valley 166,000 43,700 86,500 12,500 28,600 215,000 2,800 6,400 800 1,700 2,000 3,698.000 1,037,000 1,811,000 101.000 2,065,000 1,818,000 3,867,000 1,087,000 1,898,000 4 5 6 Imperial Valley _ .. Colorado River _ . Lanfair Valley APPROXI- MATE TOTALS 113,000 2,095,000 2,035,000 552,000 13,700 10,530,000 11,100,000 UNIT VALUES OF WATER USE Unit values of water use were determined in accord- ance with methods as set forth in Chapter II, "Meth- ods and Procedures." Available data from recent in- vestigations in the Colorado Desert Area were utilized whenever possible in order to refine estimates derived or computed from climatological data. Irrigation Water Use Estimates of unit values of water use in the Coa- chella Valley, Salton Sea, Imperial Valley, and Colo- rado River Hydrographic Units of the Colorado Des- ert Area were based on data resulting from actual soil moisture depletion studies conducted in the Coachella Valley, and upon a study of inflow to and outflow of water from the Imperial Valley during a recent period. Unit values of water use for Lanfair •214 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Valley were assumed to be the same as estimated for hydrographic units on the lower Mojave River in the Lahontan Area. As set forth in the discussion of land use. it is the practice in some localities to raise two or three crops on the same land in a given season. The resulting increased use of water was considered in estimating - average unit values of water use for truck crops. Unit mean seasonal consumptive use of applied water on farm lots was estimated to be about 0.5 foot in depth, and of precipitation about 0.3 foot of depth. These estimates were employed for both present and probable ultimate conditions of de- velopment. Climatic factors affecting consumptive use of water were not sufficiently variable to justify the use of different unit values of water use in each hydro- graphic unit. Table 159 presents the estimated unit values of mean seasonal consumptive use of applied irrigation water and of precipitation on lands de- voted to crops of the various groups. TABLE 159 ESTIMATED MEAN SEASONAL UNIT VALUES OF CON- SUMPTIVE USE OF WATER ON IRRIGATED LANDS, COLORADO DESERT AREA (In feet of depth) Crop Alfalfa Pasture Orchard Citrus Dates Vineyard Truck crops Sugar beets Cotton Rice Hay and grain Miscellaneous field crops Hydrographic units Coachella Valley, Sal- ton Sea, Imperial Valley, and Colorado River Ap- Precip- plied ita- water tion 4.2 0.3 5.0 0.3 2.3 0.3 4.0 0.3 6.0 0.3 3.0 0.3 3.0 0.3 2.5 0.3 3.0 0.3 5.0 0.3 1.8 0.3 2.4 0.3 Total 4.5 5.3 2.6 4.3 6.3 3.9 3.3 2.8 3.3 5.3 2.1 2.7 Twentynine Palms and Lanfair Vallev Ap- Precip- plied ita- water tion 2.9 0.3 2.7 0.3 2.2 0.3 2.4 0.3 1.5 0.3 1.0 0.3 1.6 0.3 Total 3.2 3.0 2.5 2.7 1.8 1.3 1.9 Urban and Suburban Water Service Areas Present unit seasonal values of use of water on urban and suburban water service areas of the Colo- rado Desert Area were estimated largely on the basis of available records of delivery of water to the areas, as compiled by municipalities and other public Avater service agencies. Probable ultimate values of water deliveries were estimated by applying to the present values derived percentage factors to account for ex- pected future increase in population densities and in per capita water use. Table 160 presents the estimates dl' present and probable ultimate unit seasonal values TABLE 160 ESTIMATED MEAN SEASONAL UNIT VALUES OF WATER DELIVERY IN URBAN AND SUBURBAN AREAS, COLO- RADO DESERT AREA (In feet of depth) Hydrographic unit Gross delivery* Refer- ence number Name Present Probable ultimate 1_ 1.2 1.7 1.6 1.7 1.5 2.5 9 3.4 3 3.2 4 3.7 5 2.5 6 Lanfair Valley - 2.2 * Assumed equivalent to consumptive use of applied water. of gross water deliveries to and consumptive use of water on urban and suburban water service areas. Other Water Service Areas Unit values of water use on the miscellany of service areas grouped in this category were derived generally from measured or estimated present deliv- eries of water to the typical development involved. In most cases the estimates were made in terms of per capita use of water, and the actual acreage of the service area was not a significant factor. In such cases the aggregate amount of water deliveries is relatively very small, and negligible recovery of return flow is involved. For purposes of study, therefore, the esti- mated unit values of delivery of water to these facili- ties were considered to be also the measures of con- sumptive use of applied water. Both the National Forest and Park Services pro- vided estimates of present and probable ultimate unit deliveries of water to all facilities within their juris- diction. The estimates were generally in terms of per capita iise of water, and were based on actual meas- urements and experience. They varied widely from place to place and in type of use, and for this reason are not detailed herein. The value of unit use of water by military estab- lishments was derived on a per capita basis, from available records of delivery of water and estimates of population of the areas involved. Present consump- tive use of applied water on these military bases is estimated to average about 75 gallons per capita per day. It was assumed that this value will hold in the future. For other water service areas not encompassed by the foregoing specific types of water service, unit values of consumptive use of applied water under probable ultimate conditions of development were assigned on a per capita basis. In such areas, a sparse residential, industrial, and recreational development is expected in the future. For areas below 3,000 feet COLORADO DESERT AREA 215 in elevation it was estimated that the ultimate popu- lation density will average about four persons per square mile, and that per capita consumptive use of water will be about 70 gallons per day for a period of six months. In areas above 3,000 feet in elevation the same per capita use and density estimates were made, but it was assumed that the average period of water use will be of only three months' duration. CONSUMPTIVE USE OF WATER Estimates of the amounts of water consumptively used in the Colorado Desert Area were derived by applying the appropriate unit values of water use to the water service areas involved. The estimates represent the seasonal amount of water use under mean conditions of water supply and climate. Table 161 presents estimates of present consumptive use of applied water and precipitation on areas having water service. Table 162 presents the corresponding estimates for probable ultimate conditions of develop- ment, but excludes areas having rights in and to the waters of the Colorado River. FACTORS OF WATER DEMAND In addition to the amount of water consumptively used in a given service area, certain factors relating to the water requirements, such as necessary rates, times, and places of delivery of water, quality of water, losses of water, etc., must be given considera- tion in the design of water development works. In the Colorado Desert Area the most important of these demand factors are associated with the supply of water for irrigation. Those factors related to the supply of water for urban, suburban, recreational, and other uses are of secondary importance. The demand factors most pertinent to design of works to meet water requirements of the Colorado Desert Area are discussed in the following sections. Monthly Distribution of Water Demands Unlike nearly all other areas of the State, there is a considerable demand for irrigation water during the entire year in the Colorado Desert Area. The effective precipitation is very minor in amount, and irrigation water must be supplied on a continuous TABLE 161 ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF WATER ON PRESENT WATER SERVICE AREAS, COLORADO DESERT AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Unclassified areas Approximate Refer- Name total consumptive ence number Applied water Precipitation Applied water Applied water Applied water use of applied water 1 2 3 Twentvnine Palms - Coaehella Valley 5,600 119,000 8,900 1,395,000 218,000 600 12,700 800 117,000 21,000 negligible .300 negligible 2,300 1,300 900 7,200 300 13,100 2,000 300 47 600 6,800 126,000 9 200 4 1,458 000 5 . 221 000 6 APPROXIMATE TOTALS. .. 1,746,000 152,000 3,900 23,500 47,900 1,821,000 TABLE 162 PROBABLE MEAN SEASONAL CONSUMPTIVE USE OF WATER ON ULTIMATE WATER SERVICE AREAS, COLORADO DESERT AREA (Excluding lands having rights in and to the waters of the Colorado River) (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Approximate total consumptive Name ence number Applied water Precipitation Applied water Applied water Applied water use of applied water 1 340,000 128,000 178,000 38,200 80,700 396,000 46,400 11,300 22,600 3,300 7,500 61,000 1,800 400 600 100 200 1,800 7,000 21,800 2,600 4,300 4,400 1,500 200 400 100 500 400 350,000 2 150,000 3 __ 182,000 4 38,400 5 85,700 6 403,000 APPROXIMATE TOTALS- 1,161,000 152,000 4,900 40,100 3,100 1,209,000 216 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 163 DISTRIBUTION OF MONTHLY WATER DEMANDS, COLORADO DESERT AREA (In per cent of seasonal total) Locality and purpose January Feb- ruary March April May June July August Sep- tember October Novem- ber Decem- ber Total Irrigation demand Coachella Valley ground water pumpage, 1936 through 1937 Coachella Canal diversion, 1951 through 1952 __. 3.0 4.0 6.1 5.4 6.7 4.5 7.7 5.0 5.8 6.7 6.2 7.1 4.8 7.0 7.0 7.4 9.5 9.5 7.6 5.6 7.8 10.0 8.5 10.1 10.5 9.8 7.4 7.3 12.0 11.3 9.7 10.6 8.9 11.6 8.3 12.0 10.8 9.4 10.1 7.9 12.0 10.1 13.0 11.4 9.4 10.6 8.9 14.3 12.2 12.0 11.8 8.0 9.7 9.1 12.8 11.0 11.0 11.2 8.0 9.1 9.2 11.2 9.4 7.0 8.6 10.3 7.4 9.3 6.5 6.7 5.0 5.5 7.4 5.7 8.4 4.9 5.9 3.0 3.7 5.4 5.2 7.1 4.4 6.6 100.0 100.0 Imperial Valley, 1946 through 1949- Palo Verde Valley, 1946 through 1949 100.0 100.0 Urban demand Palm Springs, 1938 through 1948- - Indio, 1948 through 1949- . El Centro, 1953 100.0 100.0 100.0 basis in order to meet the consumptive requirements of the crops. Demand for irrigation water in the Colo- rado Desert Area varies from about 5 per cent of the seasonal total during the winter months to over 12 per cent in the summer months. Urban water demands have a variation similar to demands for irrigation supplies, although the gross amount of water in- volved is considerably less. Variation in demand for desert recreational areas has not been evaluated, but it is estimated that this type of water use is greatest during the desert vacation period from November through February. Representative data on monthly distribution of irrigation and urban water demands in the Colorado Desert Area are presented in Table 163. Irrigation Water Service Area Efficiency In the determination of irrigation water require- ments in the Colorado Desert Area it was found to be desirable to estimate the over-all efficiency of irri- gation practice in the various service areas. Irrigation water service area efficiency was measured by the ratio of consumptive use of applied irrigation water to the gross amount of irrigation water delivered to a service area. Present irrigation water service area efficiencies were estimated after consideration of geologic conditions of the service areas involved, their topographic position in relation to sources of water supply and to other service areas, consumptive use of water, irrigation efficiency actually achieved, usable return flow, and urban and suburban sewage outflow. Numerous studies and investigations have been made by the United States Department of Agriculture and the University of California College of Agricul- ture of use of water and the resulting drainage prob- lems in Coachella and Imperial Valleys. It has been found that individual farm irrigation efficiencies, in general, vary considerably with the crop, soil, and quality of the water supply. In the Imperial Valley all water is at the present time applied by surface application, and because of high saline content of the return water is, in most instances, used only once. The irrigated lands in Palo Verde Valley and in the Reser- vation Division of the Yuma Project, United States Bureau of Reclamation, lie immediately adjacent to the Colorado River. Irrigation water supplies are di- verted into the distribution systems of the area by gravity. Water not consumptively used returns to augment the flow in the river. Under these circum- stances water is somewhat lavishly used in accordance with the desires of the individual farm operator. Additional factors affecting the estimates of prob- able ultimate irrigation water service area efficiencies were related to the location and extent of presently undeveloped irrigable lands and the increased cost of developing water. For purposes of illustration, the weighted mean values of all irrigation water serv- ice area efficiencies within each hydrographic unit of the Colorado Desert Area are presented in Table 164. TABLE 164 ESTIMATED WEIGHTED MEAN IRRIGATION WATER SERV- ICE AREA EFFICIENCY WITHIN HYDROGRAPHIC UNITS, COLORADO DESERT AREA (In per cent) Hydrographic unit Present Reference number Name Probable ultimate 1_ 90 60 90 50 85 90 2 Coachella Valley - - 60 3 80 4 60 5 85 6 90 WATER REQUIREMENTS As the term is used in this bulletin, water require- ments refer to the amounts of water needed to provide for all beneficial uses of water and for irre- coverable losses incidental to such uses. Those water COLORADO DESERT AREA 217 requirements of the Colorado Desert Area that are primarily nonconsumptive in nature are discussed in genera] terms in the ensuing section. Following this, water requirements of the area that are consumptive in nature are evaluated, both for present and for probable ultimate conditions of development. Requirements of a Nonconsumptive Nature The principal nonconsumptive requirements for water in this area are those for flood control, fish and wildlife, mining, and hydroelectric power develop- ment. All of these are minor in amount, particularly with relation to the amount of water necessary to meet requirements for irrigation water supplies. The nonconsumptive uses listed above are individually dis- cussed in subsequent paragraphs. Flood Control. There is a present need for flood control works in portions of the Colorado Desert Area, and it is anticipated that this need will increase with the growth of the area. Minor Hood control works exist in the area at present, principally on the White- water River and for protection against flooding on the Colorado River. The effect of these works on the developed water supply is negligible. It is probable that other projects will be planned and constructed as development takes place in the future. The noncon- sumptive requirements for water imposed by such flood control works will probably be minor in extent. Fish and Wildlife. The fresh-water fishery of the Colorado Desert Area is limited almost entirely to that present in the Colorado River, but constitutes an important recreational facility in that region. While sport fishing - is available along the length of the Colo- rado River in California, the major fishing areas are in the reach between Needles and Imperial Dam. The Colorado River and existing reservoirs are stocked with warm-water fishes, principally black bass, chan- nel catfish, bluegill, and crappie, although trout can be found near the California-Nevada state line. The California Department of Fish and Game has recently planted a variety of salt-water species of fish in the Salton Sea, in an attempt to augment the meager fauna of this large body of water. Surveys to date indicate that only one species, a croaker from the Gulf of Lower California, has survived and multi- plied. The prolific breeding habits and the limited size of the croaker offer the possibility of an abundant supply of food for a larger salt-water game fish, should such be introduced. The Department of Fish and Game and the University of California at Los Angeles are cooperating in studies to develop the large recrea- tional potential of this rich inland sea. Under present conditions and with the limited available water supplies, streams other than the Colo- rado River rarely have perennial flow, thus definitely limiting their potential for fishery recreational use. Future development of storage reservoirs may expand fishery opportunities in the area. The higher elevations of the Colorado Desert Area afford minor sport hunting of deer and small game. Migratory waterfowl frequent the Salton Sea, as well as the area of the Colorado River. At present there are four wildlife management areas in the Colorado Desert Area, of which the two in the Salton Sea area are supervised by the California Department of Fish and Game. The other two management areas, along the Colorado River, are supervised by the United States Fish and Wildlife Service. It is probable that such water as is necessary to maintain these wildlife management areas will be available from return flows from other areas. Mining. The production and refining of gold, silver ores, lead, and copper in the Colorado Desert Area require very minor amounts of water, most of which is available for re-use. The amounts of water used for the washing of sand and gravel, the produc- tion of pumice, and mining of iron ore are negligible. Hydroelectric Power. The nonconsumptive water requirements for hydroelectric power generation on the main stem of the Colorado River are not consid- ered in this bulletin. Colorado River water conveyed by the All-American Canal to the Imperial and Coachella Valleys is used for the generation of power, but such use is incidental to its principal purpose, the import of water to the Colorado Desert Area for agricultural and municipal uses. Appreciable water requirements for generation of hydroelectric power are not expected to develop in the future, in view of prevailing water supply and topographic conditions. Requirements of a Consumptive Nature Estimates of present water requirements within hydrographic units of the Colorado Desert Area are presented in Table 165. Table 166 presents corre- TABLE 165 ESTIMATED MEAN SEASONAL REQUIREMENTS FOR WATER ON PRESENT WATER SERVICE AREAS, COLO- RADO DESERT AREA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and sub- urban areas Other water serv- ice areas Refer- ence number Name Approxi- mate total 1 3 Twentynine Palms . Coachella Valley 6,200 198.000 9,900 2,790,000 257,000 100 600 100 4,600 2.600 900 7,200 300 13,100 2,000 300 47,600 7,500 206,000 10,300 4 5 6 Imperial Valley Colorado River. __ Lanfair Valley APPROXIMATE TOTALS 2,855,000 262,000 3.261,000 8,000 23.500 47,900 3,341,000 ■2 IS WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 166 PROBABLE MEAN SEASONAL REQUIREMENTS FOR WATER ON ULTIMATE WATER SERVICE AREAS, COLORADO DESERT AREA (Excluding lands having rights in and to the waters of the Colorado River) (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and sub- urban areas Other water serv- ice areas Refer- ence number Name Approxi- mate total 1 ■> 3 4 5 Twentynine Palms . Coachella Valley Salton Sea Imperial Valley Colorado River Lanfair Valley _ APPROXIMATE TOTALS 378,000 213,000 223,000 03,700 94,900 441,000 3,700 700 1,300 200 500 3,700 7,000 21,800 2,f>00 4,300 4,400 1,500 200 400 100 500 400 390,000 23(1,000 227,000 (14,000 100,000 450,000 1,414,000 10,100 40,100 3,100 1,467,000 sponding estimates for ultimate conditions of develop- ment, but excludes areas having rights in and to the waters of the Colorado River. These mean seasonal values represent the water other than precipitation needed to provide for beneficial consumptive use of water on irrigated lands, urban and suburban areas, and other water service areas, and for irrecoverable losses of water incidental to such use. The estimates were derived from consideration of the heretofore presented estimates of consumptive use of applied water, and of water service area efficiencies of hydro- graphic units. Water requirements for the Twentynine Palms. Salton Sea, and Lanfair Valley Hydrographic Units take into consideration the re-use of portions of the ap- plied water by storage and pumping from the subsur- face basins. Present water requirements estimated for the Colorado River Hydrographic Unit are the sum of the beneficial consumptive use of Colorado River water and the estimated irrecoverable loss accompany- ing the diversion and use. The estimated water service area efficiency in this unit was established on this basis. At the persent time return Hows from the Coachella Valley and Imperial Valley Hydrographic Units drain into the Salton Sea and are not available for subsequent use. Supplemental Requirements The probable ultimate supplemental water require- ment in the Colorado Desert Area was evaluated as the difference between the present and ultimate water requirements. The developed water supply available from the Colorado River was assumed to be the amount for which agencies within the State of California have entered into contracts with the United States Depart- ment of the Interior. Apportionment of this water supply among hydrographic units in the Colorado Desert Area was made on the basis of entitlements as set forth in the 1931 Seven-Party Agreement. The total annual quantity apportioned to this area in the aforesaid agreement was 4,150,000 acre-feet. This is believed to be sufficient to satisfy the ultimate water requirements of the lands having rights in and to the waters of the Colorado River. Table 167 presents estimates of the probable ulti- mate supplemental water requirements in the Colo- rado Desert Area, except on lands having rights in and to the waters of the Colorado River. TABLE 167 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL WATER REQUIREMENTS, COLORADO DESERT AREA (Excluding lands having rights in and to the waters of the Colorado River) (In acre-feet) Hydrographic unit Present Reference number Name Probable ultimate 1 382,000 2 Coachella Valley 176,000 3 . 217,000 4 64,000 5 99,100 6 450,000 APPROXIMATE TOTALS. 1 ,388,000 CHAPTER X SUMMARY This chapter constitutes a summary, on a general- ized state-wide basis, of the determinations of water utilization and requirements presented in the preced- ing chapters. It is prefaced by a brief description of California, its characteristics, and its potential for future growth and development, particularly as re- lated to requirements for water. As has been stated, the area of the State was divided into seven major hydrographic areas in order to facilitate the present state-wide studies. The land areas of each of the seven hydrographic areas are given in Table 168. Locations and boundaries of the areas are shown on Plate 8. TABLE 168 AREAS OF HYDROGRAPHIC AREAS, STATE OF CALIFORNIA Refer- ence number Hydrographic area Acres 1 12,500,000 2 San Francisco Bav 2,530,000 3 7,221,000 4 South Coastal 6,995,000 38,050,000 li 7 Lahontan 20,970.000 12,420,000 APPROXIMATE TOTAL 100,690,000 The State of California, bordering the Pacific Ocean over 10 degrees of latitude, occupies a commanding position on the western coast of North America. The towering peaks of the Sierra Nevada on the north and the wide deserts on the south form the eastern boundary of the State. With an average width of about 275 miles, California has a land area of over 100,000,000 acres. A great agricultural economy oc- cupies the rich valley lands and much of the lower foothill area. Magnificent stands of timber are located on the mountain lands of the northern half of the State, and mineral resources, including construction materials, ores, and oil and gas, are found in many places. Excellent ports for world-wide commerce are located along the coast, inducing the growth of major industrial centers. About 7,000,000 acres are presently devoted to irrigated agriculture, and over 1,000,000 acres are occupied by urban and suburban develop- ments. Many thousands of visitors to the State each year, as well as the majority of the resident popula- tion, utilize the outstanding recreational and scenic opportunities for vacationing, bunting, and fishing. The population of California increased from some 93,000 to about 10,600,000 in the century between 1850 and 1950, and is estimated to be well over 12,- ()()(),()()() in 1955. The general nature of the climate of California is the result of three controlling factors, the latitude, the influence of the Pacific Ocean, and the orienta- tion and extreme range of topography. The situation of the Pacific high-pressure area with respect to the California coast determines the general effect of Pa- cific storms upon the weather. The influence of the ocean gives the immediate coastal areas a maritime climate. However, the unusually wide variations and abrupt discontinuities in the climate of California are due principally to the mountain ranges. Climatic con- ditions vary from mild and equable along the coast, to alpine-like in the high mountain areas of the Cas- cade Range and the Sierra Nevada, to hot and arid in the deserts of the southeast. Precipitation mainly occurs during winter months, as rain at lower elevations and as snow in the higher mountain regions. Seasonal precipitation at sea level on the coast decreases from a depth of about 10 inches in the north to about 10 inches in the south. In the Central Valley it varies from about 38 inches at Red- ding to little over 6 inches at Bakersfield. In the Colo- rado Desert Area the average seasonal depth of pre- cipitation on the valley floor is less than 4 inches. "Wet and dry periods lasting for several years, in which average precipitation departs far from the mean, are frequently experienced in California. One of the most severe recorded dry periods in most of the State extended from 1928 through 1934, and an- other severe drought was experienced in the southern part of the State from 1895 through 1904. The seasons of 1923-24 and 1930-31 were generally the driest throughout California since adequate records have been maintained. The estimated mean seasonal natural runoff of Cali- fornia's streams is about 71,000,000 acre-feet. The major runoff contributions come from the North Coastal Area, which furnishes about 41 per cent of the total for the State, and from the Sacramento Val- ley portion of the Central Valley Area, which fur- nishes about 32 per, cent. Runoff from the coastal streams closely follows the pattern of precipitation, while a substantial part of that from inland moun- tainous areas is delayed until the late spring and summer snowmelt period. Estimated mean seasonal runoff for the various hydrographic areas is pre- sented in Table 169. (219) 220 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 169 ESTIMATED MEAN SEASONAL FULL NATURAL RUNOFF OF HYDROGRAPHIC AREAS, STATE OF CALIFORNIA Refer- Hydrographic area Runoff ence num- ber In acre-feet In percent of total 1 2.. _.. North Coastal 28,890,000 1,245,000 2.448,000 1,227,000 33,640,000 3,177,000 221,000 40.8 1.8 3 Central Coastal . 3.4 4 South Coastal .. 1.7 5 Central Valley-. 47.5 6 4.5 7 0.3 APPROXIMATE TOTALS _ 70,850,000 100.0 TABLE 170 ESTIMATED PRESENT AND PROBABLE ULTIMATE POPU- LATION WITHIN HYDROGRAPHIC AREAS, STATE OF CALIFORNIA The outstanding characteristic of natural stream runoff in California is the maldistribution of this basic resource. Over 72 per cent of the runoff occurs north of a line drawn roughly through Sacramento. In contrast, an estimated 77 per cent of the present water requirement and 80 per cent of the forecast ul- timate requirement is found south of the same line. As shown on Plate 4, at least 223 valley fill areas, which may or may not contain usable ground water, have been identified throughout California. Exten- sive ground water basins provide natural regulation for more than half of the water presently used for irrigation and urban purposes. Draft on many basins now exceeds replenishment, "and in some instances the overdraft is of such magnitude as to threaten irreparable damage to these valuable storage reser- voirs. However, the vast available underground stor- age capacity, estimated to be about 133,000,000 acre- feet in the Central Valley alone, will provide regulation for sufficient water to meet California's ultimate water requirement when operated coordi- nately with available surface reservoirs. The population of California has almost doubled in the past 20 years, and has increased over 600 per cent since 1900. The widespread distribution of urban population is evidenced by the fact that in 1950 there Avere 19 cities with populations in excess of 50,000. Recent increases in population in suburban areas have in many cases been proportionately greater than within city limits. Table 170 presents the 1950 popula- 1 ions of the seven hydrographic areas and a forecast of their populations under ultimate conditions. Industrial activity is a major influence in urban development of California, and is accelerating yearly. Many industries from eastern and midwest areas have established basic manufacturing plants here, and many others have located branch installations for final assembly of consumer products. Basic indus- tries founded on local resources include the process- ing of agricultural products, ores, petroleum, steel, and timber. Aircraft production, utilizing materials Refer- ence number Hydrographic area Present (1950) Probable ultimate 1 217,000 2,555,000 377,000 5,388.000 1,830,000 98,000 121,000 750,000 2 3 4 San Francisco Bav - 1 3,4(10,000 1,400.000 18,950,000 5 0,750,000 6 600,000 7 500,000 APPROXIMATE TOTALS.- 10.590,000 42,410,000 largely imported from others parts of the country, is an outstanding processing industry. Many outstanding projects for the purpose of de- veloping and distributing the water supplies neces- sary for maintenance of the urban and industrial economy of California have been built in the past. Among these are the works to provide municipal sup- plies for the Cities of San Diego, Los Angeles, San Francisco and Oakland, and their environs, importing water from such distant sources as the Sierra Nevada and the Colorado River to the several communities. The indicated continuation of growth of population and industry points to even more imposing develop- ments to meet the future water requirements for urban and industrial purposes. Most of the commercial stands of timber in Cali- fornia are found in the North Coastal Area, and above an elevation of 3,000 feet on the western slopes of the Sierra Nevada, while less important stands occur throughout the State. These timbered areas are shown on Plate 6. The rate of timber growth on some 16,000,000 acres of lands susceptible of commer- cial development is estimated to be about 1,200,000,- 000 board feet per year. Under ultimate conditions and with adequate management, an annual sustained yield of about 3,800,000,000 board feet is considered possible. Many timber by-products are now processed within California, and it is expected that eventually most logging and milling residues will be used in manufacturing processes. The use of water by the timber industry constitutes only a relatively minor requirement. However, with the establishment of cer- tain timber by-product industries, such as the manu- facture of pulp and rayon, serious problems relating to waste disposal and its effect on water quality may arise. The discovery of gold in 1848, which so spectacu- larly stimulated the development of the west, was followed by widespread production of gold and many other minerals in California. Because of recent un- favorable economic conditions, the mining of gold lias fallen from its former commanding position, SUMMARY 221 although substantial production still results from the working of auriferous gravels, largely by dredgers. The location and extent of the auriferous gravel deposits are shown on Plate 6. The early-day non- consumptive water requirement for hydraulic mining of gold was substantial, but has declined to practi- cally nothing. A possible future revival of the indus- try would impose a reservation on the available reservoir storage capacity of the State to impound debris and tailings. Other than gold, the extractive industries of Cali- fornia now include the production of many metals and minerals, including a wide variety of industrial and construction materials, as well as the production of petroleum and natural gas. Iron ore processing at the Kaiser plant near Fontana provides the State with a basic steel industry. Petroleum extraction is centered principally in the southern part of the Cen- tral Valley and along the southern coast. Natural gas is likewise produced in these localities, and also in the north and central portions of the Central Val- ley. The processing of petroleum is centered around Los Angeles and San Francisco Bay. In general, these extractive industries do not impose significant water supply problems, their reqiiirements being rela- tively small as related to other uses of water. How- ever, as in the case of the timber industry, the prob- lems of waste disposal inherent in some of these industries impose a threat on the maintenance of satisfactory water quality in streams and ground water basins. By far the largest use of water in California is for agriculture, a condition that will continue to prevail even under conditions of ultimate development. The present use of water for all purposes other than agri- culture is estimated to be only about 8 per cent of the total, and will increase to about 14 per cent ulti- mately. In 1950 there were 103 irrigation districts within the State, with a gross area of about 3,960,000 acres, of which about 3,080,000 acres were considered by the districts to be irrigable. In the same year approximately 6,300,000 acre-feet of water were de- livered by these districts to over 2,170,000 acres of irrigated lands. The area of all irrigated lands in California, comprising nearly 6,900,000 acres in 1950, is approximately 25 per cent of the jtotal area irri- gated in the United States. A very large portion of the water to support irrigated agriculture in Cali- fornia has been developed as a result of the enter- prise of local public districts. The Central Valley Project, which supplements irrigation supplies of the San Joaquin Valley with exchanged water from the Sacramento Valley, is an exception in this respect, having been constructed by the Federal Government. Major projects, surpassing the size and scope of any existing developments, will be required to enable de- sirable future expansion of irrigated agriculture in the State. Electric power to meet the rapidly growing de- mands in California is produced by both fuel-electric and hydroelectric generation. At the present time the power demands of the State are being met principally by three major public utilities and several large mu- nicipal utilities. The production of these and other smaller privately and publicly owned systems is sup- plemented by power generated at several hydroelec- tric installations operated by the Federal Govern- ment. The total installed power capacity within the boundaries of the State in 1953 was about 6,800,000 kilowatts, of which approximately 2,870,000 kilowatts were for hydroelectric generation. The theoretical possible hydroelectric power capacity within the State is of* the order of 10,700,000 kilowatts. The de- velopment of additional hydroelectric power is an important consideration in future water resource development planning. The climatic advantages and wide variety of nat- ural attractions of California provide unparalleled opportunities for recreational development. However, the amount of water actually consumed for domestic and service facilities in recreational areas is a very minor part of the aggregate requirement of the State. Waters used for boating, swimming, and other water sports are generally available naturally or as a result of works constructed for other purposes. The most substantial use of water in connection with recreation relates to the preservation and propagation of fish and wildlife, which use is nonconsumptive in nature. The principal consumptive use of water for recrea- tional purposes is in connection with the maintenance of ponds and feeding areas for migratory wild fowl. It is anticipated that public demand for the preserva- tion and enhancement of recreational facilities will be sufficient in most instances to assure provision of water supplies necessary for such purposes. Flood control is important as it relates to the de- velopment of water resources in California. The sporadic nature of rainfall is conducive to major winter flood damage in many parts of the State. Accelerated snowmelt due to unseasonable early spring temperatures frequently creates problems in conserving and controlling the resultant runoff. The destruction and havoc caused by floods in California have frequently been accompanied by the economic anomaly of the wastage of huge amounts of water into the ocean in areas of deficient water supply. Major flood control activities include projects on the Sacra- mento and San Joaquin Rivers and extensive works in southern California, principally in the Los An- geles metropolitan area. Flood control in the past has been largely a joint endeavor between the United States, represented by the Corps of Engineers, the State, and local public interests. The magnitude of the flood problem can be gaged by the expenditure to date for such activities, which is estimated to be about $335,000,000 in the Sacramento and San Joa- 222 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA quin River Basins and in Los Angeles County. Addi- tional large sums have been expended in other areas. A multiplicity of other problems is involved in the development and use of the waters of California for beneficial purposes. These include the repulsion of sea water from underground basins, drainage of high watertable lands, maintenance of satisfactory salt balance in irrigated areas, and protection and mainte- nance of the quality of fresh waters. Solutions to these problems, and estimates of the amounts of water necessary to satisfy their requirements, must be de- veloped in conjunction with future proposals for definite projects. PRESENT AND ULTIMATE WATER SERVICE AREAS Determinations of the location, nature, and extent of presently irrigated urban and suburban and other water service areas were made in all hydrographic areas of the State. At the same time, all lands were classified as to their suitability for development under probable ultimate conditions. The resulting data were utilized in determining the present and probable ulti- mate water requirements for all lands in California. Since the lands of the Colorado Desert Area having rights in and to the waters of the Colorado River have available a sufficient water supply for their ultimate development estimates of ultimate water service areas and requirements for these lands were excluded from this bulletin. Irrigated Lands It was determined that under present conditions of development about 6,870,000 acres are irrigated in California in a given year, on the average. It was further estimated that a gross area of about 19,050,- 000 acres is suitable for irrigated agriculture, and that under ultimate conditions of development in the State a net area averaging about 16,250,000 acres will actu- ally be irrigated. On an areal basis, pasture, hay and grain, and al- falfa now constitute the dominant irrigated crops in California, and it was estimated that they will com- prise about 43 per cent of the estimated ultimate crop pattern. However, the aggregate of other crops such as cotton, citrus, orchard, vineyard, and truck, is of equal or more importance economically. A summary of the presently irrigated acreage, segregated into various crop groups, is presented in Table 171. A similar crop pattern for probable ultimate conditions of development is presented in Table 172. Urban and Suburban Water Service Areas Under present conditions approximately 1,055,000 acres in California are devoted to urban and suburban types of land use. For the most part, the business, TABLE 171 AREAS OF PRESENTLY IRRIGATED LANDS WITHIN HYDROGRAPHIC AREAS, STATE OF CALIFORNIA (In acres) Hydrographic area number and name Crop 1 2 3 4 5 6 7 Approximate total North Coastal San Francisco Bay Central Coastal South Coastal Central Valley Lahontan Colorado Desert Alfalfa 24,400 67,500 97,500 4,400 16,000 2,800 4,100 1,800 8,500 6,800 3,100 38,400 84,500 10,300 3.600 2,000 30,900 24,500 75,900 26,300 129,000 38,300 10,300 3,000 42,500 19,800 41,200 11,600" 35.000 125,000 19,700 279,000 42,900 585,000 757,000 795,000 370,000 295,000 346,000 387,000 45,000 448,000 723,000 96,200 38,000 81,700 2,000 4,200 5,600 203,000 100,000 8,200 85,400 34,100 78,000 1,500 4,500 10,000 34,000 6,100 986,000 984 000 Hay and grain Pasture 1,057,000 549,000 67,200 38,100 295,000 737,000 539,000 Miscellaneous field crops Sugar beets Beans . Rice _ _ Truck.. Orchard, general Citrus 339,000 53,200 465,000 Walnuts. Vineyards Cotton . 757 000 Dates . . 6 100 Flowers 2 100 Net irrigated areas Farm lots 213,000 4,100 6,400 163,000 338,000 5,900 10,800 617,000 b 35,000 4,751,000 108,000 265,000 228,000 2,800 4,900 565,000 7,900 13,900 6,875,000 129,000 No n water service areas 336,000 APPROXIMATE GROSS IRRIGATED AREAS.. 223,000 163,000 355,000 652,000 5,124,000 236,000 587,000 7,340,000 " Not segregated. b Included in urban and suburban areas. c Includes miscellaneous crop types not otherwise segregated. SUMMARY 223 TABLE 172 PROBABLE ULTIMATE AREAS OF IRRIGATED LANDS WITHIN HYDROGRAPHIC AREAS, STATE OF CALIFORNIA (In acres) Hydrographic area number and name Crop 1 2 3 4 5 6 7 Approximate total North Coastal San Francisco Bay Central Coastal South Coastal Central Valley Lahontan Colorado Desert d Alfalfa . 124,000 317,000 297,000 34,200 75,600 164,000 250,000 202,000 69,000 60,100 1 16,000 68,600 45,000 b 1,112,000 1,513,000 1,052,000 995,000 320,000 647,000 854,000 899,00(1 6,300 55,100 181,000 14,600 95,000 43,000 800 2,200,000 3,009,000 2,662,000 Miscellaneous field crops. _ . 1,326,000 445,000 72,900 72,900 738,000 524,000 708,000 104,000 738,000 Truck 51,800 28,100 219,000 113,000 32,600 193,000 59.900 325.000 53.000 53,200 42,200 68.400 14.400 10,500 1,109.000 966,000 172,000 53 16,900 41,200 710,000 2,261,000 54,800 40.900 3,600 2,500 864.000 2 265,000 2,500 Net irrigated areas . . - Farm lots . . _ _ _ . Nonwater service areas . _ - 869,000 14,700 174,000 62,400" 1,400 2,000 1,166,000 19,500 183,000 1,024,000 35,800 96,400 10,040,000 166.000 1 .".47.000 2,612,000 56.300 430,000 475,000 10,100 67,100 16,250,000" 304,000 2,500,000 APPROXIMATE GROSS IRRIGATED AREAS.. 1,058,000 65,800 1,368,000 1,156,000 11.750.000 3,098.000 552,000 19,050,000 a Crop pattern not forecast. Total without reclamation of tidelands. b Includes miscellaneous crop types not otherwise segregated. c Total of segregated crop pattern, except San Francisco Bay Area, is 16,190,000 acres 11 Excluding lands having rights in and to waters of the Colorado River. commercial, and industrial establishments and sur- rounding homes included in this classification receive a municipal type of water supply. It is anticipated that future urban and suburban growth in most regions of the State will parallel the development of agricultural lands. Metropolitan areas, however, particularly those bordering the Pacific Ocean, may be expected to respond to national and world-wide economic conditions, in addition to those created by the expansion of California as an agricultural state. It is estimated that urban and suburban water serv- ice areas under ultimate conditions of development will occupy about 3,435,000 acres. Other Water Service Areas The remaining lands of California, other than those that are irrigated or urban and suburban in char- acter, were not classified in detail with regard to water service. Of a total of about 92,760,000 acres of such remaining lands, approximately 182,000 acres actually receive water service at the present time. These rela- tively minor present water service areas, herein termed ''Unclassified," consist largely of scattered develop- ments in national forests and monuments, public beaches and parks, private recreational areas, wild fowl refuges, and military reservations. It is estimated that under probable conditions of ultimate development, approximately 76,910,000 acres of such lands will be served with water in amounts sufficient for their needs. No attempt was made to segregate these "other water service areas" in detail with regard to the nature of their probable ultimate water service. By far the greater portion of the lands is situated in rough, mountainous terrain, much of which is presently unaccessible. It is expected that even under conditions of ultimate development this portion will be only sparsely settled and will have only very minor requirements for water service. Summary Table 173 summarizes data relative to present water service areas in the various hydrographic areas of California, classified by broad land usage group- ings. Similar data relating to probable ultimate con- ditions of development are given in Table 174. UNIT VALUES OF WATER USE It is anticipated that the values of water use and requirement estimated for this bulletin will be used in connection with long-range water resources plan- ning. The unit values expressed, therefore, are those that would occur under mean conditions of water sup- ply and climate, and represent the average use of water when an adequate water supply is available. They do not reflect possible effects of any present shortages in water supply. 224 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 173 SUMMARY OF PRESENT WATER SERVICE AREAS WITHIN HYDROGRAPHIC AREAS, STATE OF CALIFORNIA (In acres) Refer- ence num- ber Hydrographic area Gross irrigated area Urban and suburban areas Unclassi- fied areas Approxi- mate total 1 2 3 4 5 6 7 North Coastal San Francisco Bay _ . Central Coastal South Coastal Central Valley Lahontan Colorado Desert. . APPROXIMATE TOTALS 223,000 163,000 355,000 652,000 5,123,000 236,000 587,000 18.500 225.000 48.400 547,000 191,000 10,300 14,200 19.500 50.100 12,200 1,200 84,700 4,500 10,000 261,000 438,000 416,000 1,200,000 5,399,000 250,000 611,000 7,339,000 1,054,000 182,000 8,575,000 TABLE 174 SUMMARY OF PROBABLE ULTIMATE WATER SERVICE AREAS WITHIN HYDROGRAPHIC AREAS, STATE OF CALIFORNIA (In acres) Refer- ence num- ber Hydrographic area Irrigable lands Urban and suburban areas Other water service areas Approxi- mate total 1 2 3 4 5 6 7 North Coastal San Francisco Bay a _. Central Coastal South Coastal ._ Central Valley Lahontan Colorado Desert b APPROXIMATE TOTALS 1,058,000 65,800 1 ,368,000 1,156,000 11,750,000 3,098,000 552,000 53,000 1,250,000 138,000 1,611,000 292,000 53,700 13,700 11,390,000 1,222,000 5,715,000 4,228,000 26,010.000 17,820,000 10,530,000 12,500,000 2,538,000 7,221,000 6,995,000 38,050,000 20,970,000 11,100,000 19,050,000 3,411,000 76,910,000 99,370,000 a Without reclamation of tidelands. b Excluding lands having rights in and to waters of the Colorado River. A comprehensive study was made of available ex- perimental data on consumptive use of irrigation water and of records of irrigation water deliveries and return flows. Investigation was also made of the prevailing irrigation practices in the several parts of the State. For most of California, unit seasonal values of consumptive use of applied irrigation water for the various crop groups were estimated by a method developed mainly by Harry F. Blaney and Wayne D. Criddle of the federal Soil Conservation Service. However, the basic method of these authorities was modified somewhat to meet the special needs of the present investigation, and in the light of the cited study of irrigation records and practices. Unit values of water use in urban and suburban areas, other than in the San Francisco Bay Area and in most of the South Coastal Area, generally were estimated from records of present delivery and dis- posal of water, utilizing data from private and public water service agencies. Although there are large varia- tions in per capita water deliveries to various cities, analysis disclosed no firm trends in the amount of the deliveries as related to metered or unmetered water service, or as related to the cost of water to the con- sumer. More important factors in this respect seemed to be the climatological characteristics, the abundance or scarcity of water, and the nature and habits of the communities. The records of water delivery indi- cated that in recent years there has been an increase in the per capita urban requirement, and that the trend is continuing. A substantial part of the increase probably results from development of modern water- using appliances. In some communities, also, a grow- ing industrialization accounts for part of the increase. To provide for this trend, the probable ultimate unit values of water deliveries to urban and suburban areas generally were increased 10 per cent over present values. For tlic metropolitan areas in and around San Francisco, Los Angeles, and San Diego, as well as for most of the remaining urban areas in the South Coastal Area, unit values of present water use were estimated by a sampling procedure. An inventory was made of measured water deliveries in sample areas representative of each urban type. In most cases, the probable ultimate unit values were esti- mated by adjusting the present values, the adjust- ments being based upon indicated trends for each urban type. Estimates of unit values of water use in areas other than irrigated, urban and suburban, or metro- politan, were based largely on records or estimates of present water delivery. By the nature of the activi- ties involved, water utilization in most of these other water service areas is not adaptable to areal classifica- tion, and the unit values of water use consisted of per capita or per unit of production values. In areas outside of specifically classified types of development, ultimate unit values were generally expressed on a per capita basis, assumptions being made as to densi- ties of ultimate population. For lands above an eleva- tion of 3,000 feet it was assumed that occupancy would be limited to a few months of the year, thus reducing the effective seasonal unit value of water use, while lands below that elevation were assumed to be occupied for longer periods. Evaluation of unit values of water use by urban types' was generally based on the assumption that water delivery constitutes an approximate equivalent measure of consumptive use of applied water and the unavoidable losses sustained in delivery and disposal. Exceptions to this were made for unsewered absorp- tive portions of the South Coastal Area, where allow- ances were taken for return flow and re-use of sewage. AVater deliveries to unclassified and other water serv- ice areas were likewise considered to be the measures of consumptive use of applied water. Estimated weighted mean seasonal unit values of consumptive use of applied water in the seven major hydrographic areas of the State are presented in SUMMARY 225 Tables 175 and 176, respectively, for present and probable ultimate conditions. TABLE 175 ESTIMATED PRESENT WEIGHTED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF APPLIED WATER, STATE OF CALIFORNIA (In feet of depth) Refer- ence num- ber Hydrographic area Irrigated lands Farm lots Urban and suburban areas 1 1.5 1.3 1.3 1.5 2.0 2.0 3.1 1.0 0.5 b 0.5 0.5 0.5 1.1 2 3 San Francisco Bay i .6 1.0 4 0.6 5 0.7 6 0.6 7 1.7 WEIGHTED MEAN 2.0 0.5 0.9 « Included in "Unclassified Areas." b Included in "Urban and Suburban Areas." TABLE 176 PROBABLE ULTIMATE WEIGHTED MEAN SEASONAL UNIT VALUES OF CONSUMPTIVE USE OF APPLIED WATER, STATE OF CALIFORNIA (In feet of depth) Refer- ence num- ber Hydrographic area Irrigated lands Farm lots Urban and suburban areas Other water service areas 1 2 3 4 5 6 North Coastal _ San Francisco Bay - . Central Coastal South Coastal Central Valley 1.3 0.9 1.2 1.5 2.0 2.0 2.7 0.8 2.0 0.5 0.8 0.5 0.5 0.5 1.6 2.2 1.4 0.8 1.3 1.0 2.9 less than 0.01 in all 7 Colorado Desert. . WEIGHTED MEAN 1.9 0.6 1.4 CONSUMPTIVE USE OF APPLIED WATER The amount of applied water consumptively used was estimated by applying the appropriate unit value of water use to the acreage of each of the various classes and types of land use, and totaling for each service area. These estimates are summarized by major hydrographic areas of the State in Tables 177 and 178, for present and probable ultimate conditions, respectively. WATER REQUIREMENTS In broad generalization, the amount of the require- ment for water of a consumptive nature was derived by dividing the amount of consumptive use of applied water by an appropriate efficiency factor, the factor being chosen to account for unavoidable losses within TABLE 177 ESTIMATED MEAN SEASONAL CONSUMPTIVE USE OF APPLIED WATER ON PRESENT WATER SERVICE AREAS, STATE OF CALIFORNIA (In acre-feet) Ref- er- ence num- ber Hydrographic area Irrigated lands 1 ;n in lets Urban and sub- urban areas Un- classi- fied areas Approxi- mate total 1 ... 2 ... 3... 4 ___ 5 6 North Coastal San Francisco Bay. Central Coastal South Coastal _ Central Valley 317,000 209,000 426.000 919,000 9.508,000 464.000 1,746,000 4.000 3,100 h 54.400 1.400 3,900 20,900 352,000 47.400 338.000 138,000 6,100 23,500 4,500 :;:,. coo 14,600 2,400 105,000 14.100 47,900 346.000 597,000 HI 1.000 1,259,000 9,805.000 486 000 7... Colorado Desert APPROXIMATE TOTALS 1,821,000 13,590,000 66,800 926,000 224,000 14,810,000 ■ Included in "Unclassified Areas." b Included in "Urban and Suburban Areas.' TABLE 178 PROBABLE MEAN SEASONAL CONSUMPTIVE USE OF APPLIED WATER ON ULTIMATE WATER SERVICE AREAS, STATE OF CALIFORNIA (In acre-feet) Ref- Urban Other water er- Hydrographic Irrigated Farm and Approxi- nu ru- area lands lots urban service total ber areas areas 1 ... North Coastal. 1,131,000 12,200 85,200 83,500 1,312,000 2... San Francisco Bay" 72,000 2,800 2.747,000 2,500 2.824.000 3 ... Central Coastal 1,132,000 9,800 198,000 23,200 1,663,000 4 ... Soutb Coastal. 1.568,000 28.600 1,264,000 16,000 2,877,000 5 ... Central Valley . 20,100,000 83,600 372,000 301,000 20,860,000 6 ... Lahonton 5,151,000 28,200 53,700 04,800 5,298,000 7 ... Colorado Desert b _ . APPROXI- 1,161,000 4,900 40,100 3,100 1,209,000 MATE TOTALS . 30,010,000 170,000 4,760,000 494,000 36,040,000 a Without reclamation of tidelands. b Excluding lands having rights in and to waters of the Colorado River. the service area under consideration. Most noncon- sumptive requirements for water, however, are not readily susceptible of evaluation except as they re- late to actual water development projects, and sbould be evaluated with consideration to all water require- ments at the time projects are implemented. For this reason, nonconsumptive water requirements are dis- cussed only generally in this bulletin and are not sum- marized in this chapter. The requirement for irrigation water was estimated as the sum of the products of appropriate unit values of consumptive use of applied irrigation water and the areas of the various irrigated crop types, divided by estimated irrigation water service area efficiencies, or by equivalent procedure. In many instances, data available from agencies serving irrigation water per- 22(] WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA mitted direct derivation of the present efficiency factor. AVhere such data were not available or appli- cable, the efficiency of water use was estimated on the basis of available information on conveyance and dis- tribution losses, re-use of return flow, flushing water required to maintain salt balance, and topographic and geologic conditions affecting the application and use of irrigation water. Of primary importance among the topographic and geologic factors are the existence, extent, and type of ground water basins, and their positions with relation to sources of water supply and to other water service areas. The water requirements of urban and suburban areas, other than in the South Coastal and San Fran- cisco Bay Areas, were estimated as the sums of the products of appropriate unit values of water delivery and the determined total areas of urban and suburban land use. Urban water requirements of the metropol- itan areas in and around Los Angeles, San Francisco, and San Diego were estimated as the sum of the products of appropriate unit values of water delivery, times the areas of the various types of urban land use, multiplied by factors to account for water losses in conveyance and delivery throughout the water systems. Additionally, in portions of the South Coastal Area the re-use of unconsumed urban water delivered on absorptive lands was taken into account, involving consideration of the status of sewerage. For water service areas designated "unclassified" under present conditions, and for those classed as "other water service areas" under ultimate condi- tions, water requirements were estimated as the sum of the products (if derived unit values of water de- livery and appropriate factors of population or unit of production. The total requirement for water in each service area was taken as the sum of the individual require- ments for the several classes of water use, due account generally being taken of usable return flow from ap- plied water within the area. Similar consideration was made in evaluating total water requirements of larger measures of land area. Estimates of the present and probable ultimate mean seasonal consumptive require- ments for water by major hydrographic areas are presented in Table 179. SUPPLEMENTAL WATER REQUIREMENTS In areas with a present deficiency in water supply development, standard procedures were utilized to evaluate the present safe yield. By subtracting this value from the determined present water require- ment, the supplemental water requirement was de- rived. Available data on which to base estimates of present safe yield were often inadequate, and the resulting estimates of supplemental requirement are necessarily subject to error. However, they are be- lieved to be sufficiently reliable for their particular purpose, which is to provide information regarding the magnitude of water supply surpluses or defi- ciencies in the various parts of California in order to permit development of the broad pattern of The Cali- fornia Water Plan. Ultimate supplemental water requirements were evaluated as the difference between present and ulti- mate requirements for water, plus the present supple- mental water requirement in such areas as experience a present deficiency. The possible additional yield of the existing water supply works over the present re- quirement of the area served was not credited to reduction of the ultimate supplemental water require- ment, except for the water allocated from the Friant- Kern, Madera, and Contra Costa Canals. The diffi- culties inherent in defining and determining accu- rately the amount of present surface yield, and in allocating the surplus to specific water service areas TABLE 179 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL REQUIREMENTS FOR WATER, STATE OF CALIFORNIA (In acre-feet) Hydrographic unit Irrigated lands Farm lots Urban and suburban areas Other water service areas Approximate totals Name Refer- ence number Present Probable ultimate Present Probable ultimate Present Probable ultimate Present Probable ultimate Present Probable ultimate 1 488,000 301,000 641,000 1,020,000 1 2,700,000 712,000 3,261,000 1,917,000 98,300" 2,217,000 1,856,000 22,820,000 6,607,000 1,414,000'! 4,200 b 6,100 109,000 3,000 8,000 15,400 2,800" 19,600 45,000 167,000 56,000 10,100') 21,000 388,000 47,400 885,000 277,000 12,000 23,500 85,300 3,021,000" 198,000 3,635,000 741,000 107,000 40, 100 d 4,500 35,600 14,600 2,400 105,000 14,000 47,900 83,500 2,500 » 23,200 16,100 300,000 65,000 3,100 d 518,000 725,000 709,000 1.907,000 13,190,000 741,000 3,341,000 2,101,000 3,124,000" 2,458,000 2 3 San Francisco Bay 4 5 .. South Coastal 5,552,000 24 030 000 6 7 Lahontan 6,835,000 1 467 000 d APPROXIMATE TOTALS 19,120,000 36,930,000 130,000 316,000 1,654,000 7,827,000 224,000 493,000 21,130,000 45,570,000 ' Without reclamation of tidelands. h i,,',,i.f| W 'ith "Other \V;iicr Service Areas." •■ Included with "Urban and Suburban Areas." ■' Excluding lands having rights in and to waters of the Colorado Kiver. SUMMARY 227 prior to completion of a comprehensive ultimate plan, were such as to preclude their consideration in studies for the present bulletin. It should be noted that the supplemental water requirement for a major hydrographic area, or for a stream basin within that area, is not necessarily equal to the sum of the individual supplemental re- quirements of the included areas. This follows from the fact that there is usually opportunity for down- stream re-use of return flows from water applied on upstream areas, thus reducing the aggregate supple- mental requirement for the hydrographic area or stream basin taken as a whole. Estimates of present and probable ultimate mean seasonal supplemental requirements for water in the major hydrographic areas of California are presented in Table 180. TABLE 180 ESTIMATED PRESENT AND PROBABLE ULTIMATE MEAN SEASONAL SUPPLEMENTAL REQUIREMENTS FOR WATER, STATE OF CALIFORNIA (In acre-feet) Refer- ence number Hydrographic area Present Probable ultimate 1 32,000 184,000 395,000 1,785,000 279,000 1,583,000 2 2,209,000 3.. 1,902,000 4 5.. South Coastal _ 4,040,000 11,740.000 6 . . 7.. Lahontan . _ _ . 6,373,000 1,388,000 APPROXIMATE TOTALS.. 2,675,000 29,230,000 * Excluding lands having rights in and to the waters of the Colorado River. ULTIMATE EXPORT AND IMPORT OF WATER Table 181 presents a summary of estimates of run- off, yield, requirement, and surplus or deficiency of water in the several parts of California under prob- able ultimate conditions of development. As has been stated, the estimates of safe yield of the ultimate water supply development are necessarily very tenta- tive at this stage of planning, and cannot be actually fixed until final determination of The California Water Plan. However, they are believed to be ade- quate for present planning purposes. The yield estimates in Table 181 contemplate the full development of local water supplies for local use, as well as the supplies developed I'm- export from areas of surplus to areas of deficiency. In addition to the full use of surface reservoir storage capacity for regulation of stream flow, the estimates of safe yield are based on a substantial coordinated use of ground water storage capacity for this purpose. The estimates of surplus and deficiency in Table 181 do not consider exports or imports of water be- tween major hydrographic areas developed in con- nection with present rights. Rather, they are based on the inherent water resource and requirement char- acteristics of the areas. However, existing develop- ments and present rights will be given primary con- sideration in The California Water Plan. The data presented in Table 181 not only illustrate the basic geographic problem of water supply develop- ment in California, but indicate the nature of the solution to that problem. The full amount of the rights of California in and to the waters of the Colorado River must be protected to meet require- ments within the State. In addition, an average of approximately 23,000,000 acre-feet of water per sea- son ultimately must be developed from the North Coastal Area and from the Sacramento River Basin of the Central Valley Area, and exported to the re- maining water-deficient portions of the State. This conclusion provides the basis for the broad pattern of The California Water Plan. TABLE 181 SUMMARY OF ESTIMATED ULTIMATE MEAN SEASONAL EXPORTS AND IMPORTS OF WATER IN CALIFORNIA (In acre-feet) Refer- ence number Hydrographic area Mean runoff Safe yield Water requirement Surplus, available for export Deficiency, to be met by import 1 28,890,000 1,245,000 2,448,000 1,227,000 22,390.000 11,250,000 1,843,000 1,334,000 321,000 13,860,000 439,000 1,109,000 1,190,000 19,040,000 9,560,000 448,000 726,000 78.000 5,362,000 2,101,000 3,124,000 2,458,000 5,552,000 7,720,000 16,310.000 1,361,000 5,474,000 5,617.000 11,760,000 11,320,000 5,362.000 2 2,685,000 3 1,349,000 4 5 .. South Coastal . Central Valley Sacramento River Basin _ .... 4,362,000 6,750,000 6 Lahontan Area north of Mono Lake Basin 913,000 4,748,000 7 5,539,000 California's rights in and to waters of the Colorado River. Requirement for operation of works in Sacramento-San 2.093,000 2,093,000 APPROXIMATE TOTALS . 70,850,000 51,810,000 51,810,000 28,440,000 28,440,000 STATE OF CALIFORNIA GOODWIN J. KNIGHT GOVERNOR PUBLICATION OF STATE WATER RESOURCES BOARD Bulletin No. 2 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA Volume II APPENDIXES AND PLATES June, 1955 9—99801 TABLE OF CONTENTS APPENDIXES Page A. A Preliminary Projection of California Crop Patterns for Estimating Ultimate Water Requirements - 231 B. Directory of Water Service Agencies in California - 257 C. Description of Hydrographic Units - 291 D. Sources and Dates of Land Use Survey Data 305 E. Sources of Land Classification Survey Data__ - 307 F. Water Requirements for Fish and Wildlife in California _ 311 G. Hydroelectric Power Installations in California 325 II. Major Reservoirs of California 331 I. Water Quality Considerations Affecting Use of the Waters of Cali- fornia -^ 339 PLATES (Plates 1 to 15 at end of Volume II) Plate No. 1 Water Service Areas for The California Water Plan 2 Growth of Population and Cultivated and Irrigated Lands of California 3 Irrigation and Water Storage Districts 4 Valley Fill Areas 5 Electric Power Development, 1954 6 Timber Lands and Auriferous Gravel Deposits 7 Recreational Areas 8 Major Hydrographic Areas and Hydrographic Units 9 Classification of Lands for Water Service From The California Water Plan 10 Present Land Use in San Francisco Bay Area 11 Present Land Use in Los Angeles and San Diego Metropolitan Areas 12 Principal Water Supply Agencies and Works of San Francisco Bay Area 13 Principal Water Supply Agencies and Works of Los Angeles and San Diego Metropolitan Areas 14 Imported Water Supplies of San Francisco Bay Area 15 Imported Water Supplies of Los Angeles and San Diego Metropolitan Areas ( 230 ) APPENDIX A A PRELIMINARY PROJECTION OF CALIFORNIA CROP PATTERNS FOR ESTIMATING ULTIMATE WATER REQUIREMENTS BY DAVID WEEKS Professor of Agricultural Economics University of California January 15, 1954 ( 231 ) TABLE OF CONTENTS Page Introduction 233 Scope and General Procedure 233 General Assumptions 233 Population 234 United States Population Growth — Historical and Projected Trends 234 California Population Growth — Historical and Projected Trends 235 Population and the Crop Pattern 237 Consequences of Under- or Overestimates of Future Population 238 California Crop Pattern of the Late 1940 's 238 A Major Part as Indicator of the Whole 238 Irrigated Acreages ' 238 Projection of the Orchard and Vineyard Crop Acreage 240 Basic Assumptions 240 Steps in the Procedure 241 Summary of Results 241 Notes on the Method Employed 242 Page Projection of the Commercial Truck Crop and Potato Acreage 243 Basic Assumptions 244 Steps in the Procedure 244 Results of the Projection 244 Projection of the Field Crop Acreage 244 Basic Assumptions 244 Steps in the Procedure 244 Results of the Field Crop Irrigated Acreage Projections 245 Economic Implications of the Foregoing Projec- tions 247 Price and Demand Analysis in Long-term Pro- jections 248 Age Distribution of the California Orchard and Vineyard Crops in Relation to Future Acreage Requirements 249 Competition of the Different Crops for Land and for Water 250 Price Controls in Relation to Long-term Acre- age Trends 253 Acreage Allotments 254 Conclusions 256 LIST OF TABLES Table Page 1 United States Population Trends 235 2 California Population Rate of Increase 236 3 California Crop Acreages, 1949, Total and Irrigated 239 4 Bearing and Harvested Acreages of California Crops, Percentage Irrigated, 1909-1949 241 5 Total and Bearing Acreage of California Orchard and Vineyard Crops, 1946-1949 241 6 Summary of Projected Crop Pattern for Assumption of Initial Full Development of Irrigable Area of Cali- fornia 242 7 Trend and Rate of Increase of Production of Cali- fornia Deciduous Tree Fruit, 1920-1950, with Projec- tions, 1950-1980 243 Trend and Rate of Increase of Production of Cali- fornia Grapes, 1920-1950, with Projections, 1950-1980. 243 Trend and Rate of Increase of Production of Cali- fornia Citrus Fruit, 1910-1950, with Projections, 1950- 1980 Trend and Rate of Increase of Production of Cali- fornia Nut Crops, 1910-1950, with Projections, 1950- 1980 Trend and Rate of Increase of Commercial Truck Crops in California, 1920-1950, with Projections from 1950-1980 244 Trend and Rate of Increase of Irrigated Harvested Acreage of California Field Crops. 1910-1950, with Projections from 1950-1980 245 Trend and Rate of Increase of Irrigated Harvested Acreage of California Alfalfa, 1920-1950, with Projec- tions from 1950-1980 245 8 9 10 11 12 13 243 24.-, Table Page 14 Trend and Rate of Increase of Irrigated Harvested Acreage of California Cotton, 1910-1950, with Projec- tions from 1950-1980 245 15 Trend and Rate of Increase of Irrigated Harvest Acre- age of California Rice, 1910-1950, with Projections from 1950-1980 246 16 Trend and Rate of Increase of Irrigated Harvested Acreage of California Miscellaneous Field Crops, 1920- 1950, with Projections from 1950-1980 246 17 Trend and Rate of Increase of Irrigated Harvested Acreage of California Beans (Green and Dry), 1920- 1950, with Projections from 1950-1980 246 18 Trend and Rate of Increase of Irrigated Harvested Acreage of California Sugar Beets, 1920-1950, with Projections from 1950-1980 246 19 Trend and Rate of Increase of Irrigated Harvested Acreage of California Miscellaneous Intensive Field Crops, 1910-1950, with Projections from 1950-1980- 20 Trend and Rate of Increase of Irrigated Harvested Acreage of California Small Grain Crops, 1920-1950, with Projections from 1950-1980 21 Trend and Rate of Increase of Irrigated Harvested Acreage of California Extensive Hay Crops, 1920-1950, with Projections from 1950-1980—" 247 22 Yield Per Bearing Acre of Orchard and Vineyard Crops 250 23 Average Yield Per Harvested Acre of Selected Field Crops 251 24 Food Energy Yields of Irrigated Wheat and Rice in the Sacramento Valley of California 252 25 Acreage of Irrigable Lands in California Suited Only for Shallow-rooted Crops 253 247 247 Plate Al. Fig. 1A. Fig. IB. Fig. 1C. Fig. ID. Plate A2. Fig. 2A. Fig. 2B. Fig. 2C. Fig. 2D. Fig. 2E. Fig. 2F. Fig. 2C. Fig. ?H. Fig. 2T. Fig. 2.T. PLATES AND (All plates for Appendix Projected Population of United States and Cali- fornia Population of the United States (including mili- tary forces overseas) Percentage Increase per Decade of United States Population Population of California Percentage Increase of California Population Over the Population Ten Years Earlier Total and Irrigated Acreage of California Crops Citrus Fruits Nut Crops Deciduous Tree Fruits Vineyard Rice Cotton Alfalfa Sugar Beets Corn, Sorghums, Hays, and Flax Beans. Green and Dry ( 232 ) FIGURES A follow page 256) Fig. 2K. Extensive Hay Crops (Wild, Grain, and Other Tame Hav Excluding Alfalfa) Fig. 2E. Small Grains rinte A3. California Fruit. Grape, and Nut Production Fig. 3A. Deciduous Fruit Trees Fig. 3B. Grape Fig. 3C. Citrus Fruit Fig. 3D. Nut Crop Plate A4. Irrigated Harvested Acreages of California Crops Fig. 4A. Truck Crops Fig. 4B. Field Crops Fig. 4C. Alfalfa Fig. 4D. Cotton Fig. 4E. Rice Fig. 4F. Miscellaneous Field Crops Fig. 4G. Beans Fig. 4H. Sugar Beets Fig. 41. Miscellaneous Intensive Field Crops Fig. 4.T. Small Grain Crops Fig. 4K. Extensive Hay Crops APPENDIX A 233 A PRELIMINARY PROJECTION OF CALIFORNIA CROP PATTERNS FOR ESTIMATING ULTIMATE WATER REQUIREMENTS INTRODUCTION The acreage, kind, and location of the different agricultural crops grown in California may be called the "California Crop Pattern." Similarly, any area Avithin the State may have a crop pattern. The differ- ent crop patterns will use different total amounts of water per acre because each of the different crops within a given pattern requires a specific amount of water annually. Projection of the ultimate water re- quired for irrigation in California, therefore, has required a preliminary projection of the crop pattern. Like most projections of this kind, much more knowl- edge of the past, present, and future is necessary than is available. Furthermore, like other work of this nature, time and funds available usually are not ade- quate to make an exhaustive analysis, and, if such an analysis were made, there might be doubt as to how much it would reduce the error always inherent in such work. The analysis reported herein, therefore, is not exhaustive. In the course of the next few decades, most of the land area of California now considered irrigable probably will have been provided with irrigation facilities. When water actually is applied to all of these areas and when all urban areas "have been expanded to a foreseeable limit," then the State land and water resources may be said to have reached a condition of initial full Hagood, Margaret Harmon, and Jacob Siegel. "Projections of the Regional Population of the United States in 1975." Agri- cultural Economics Research, vol. Ill, no. 2, April, 1951. to 1980 — constitutes the United States population projection use in these crop pattern projections. Be- fore these crop pattern projections were completed, however, a new series of United States projections was published. 6 The "low" projection for 1975 in this new series gives a population for the United States of 198,632,- 000 which is higher than the medium projection actually used as indicated above. The projection pre- sented in Table 1, however, has been retained as the basis of these studies, believing that the results ob- tained are thus reasonably conservative. Furthermore, it is believed that there is as much danger today in believing that the high birth rates of recent years will continue unabated as there was in 1930 of believing, as many population experts did, that the low fertility rates of that period would be continued. California Population Growth— Historical and Projected Trends The choice of the method used herein for project- ing the California population has been based upon the belief that highly precise and involved methods of analysis are impractical because of the large likeli- hood of error involved in estimating the many differ- ent elements usually comprising highly involved popu- lation studies. There are many other methods, of course, by which California population growth lias been projected into the future. Most notable among these various pro- jections is that of Helen L. White and Jacob S. Siegel of the United States Bureau of the Census published in 1952. 7 This projection which employs a so-called "ratio" method gives low. medium, and high projections for 1960 of 13,380,000, 14,017,000, and 14,919,000, respectively. Even the highest of these projections is lower than the one presented in Table 2 of this report. The projection presented in Table 2 and in Figure 1C, however, lias been designed especially for the peculiar characteristics of California population growth involving as it does a highly variable immi- gration rate and a more rapid rate of total population growth than that of any of the other states. In com- parison with the White-Siegel projection mentioned above, it projects for 1960 a "reasonable lower limit of California population of 15,065,000 and for 1980 of 21,300,000. California population in 1950, according to the census enumeration, was 10,586,000. This was an in- crease of 53.3 per cent over the corresponding figure in the 1940 census of 6,907,000. Two thirds of the in- crease from 1940-1950 was by immigration of persons " U. S. Bureau of the Census. "Illustrative Projections of the Population United States by Age and Sex: 1955-1975." Cur- rent Population Reports, Population Estimates. Series P-25, no. 78. Washington, U. S. Govt. Print. Off., August 21, 1953. 7 U. S. Bureau of the Census. "Projections of the Population by States: 1955 and 1960." Current Population Reports, Popula- lUni Estimates. Series P-25, no. 56, Washington, U. S. Govt. Print. Off., January 27, 1952, 236 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA TABLE 2 CALIFORNIA POPULATION RATE OF INCREASE Population, end of decade Increase during decade Decade As enu- mer- ated Trend As enu- mer- ated Trend As enu- mer- ated Trend 1 2 3 4 5 6 thousands percent 1850-1860. 380 560 865 1,213 1 ,485 2,378 3,427 5,677 6,907 10,586 290 580 840 1,190 1,700 2,480 3,650 5,330 7,620 10,590 1860-1870 180 260 348 272 893 1,049 2,250 1.230 3,679 290 260 350 510 780 1,170 1 .680 2.290 2,970 47.4 54.5 40.2 22.4 60.1 44.1 65.6 21.7 53.3 1870-1880.. 100 1880-1890. 44 1890-1900. 42 1900-1910 43 1910-1920 46 1920-1930 47 1930-1940.. 46 1940-1950... 43 39 Projection 1950-1960. 15,057 17,744 21,294 14,090 17,750 21,300 4,471 2,687 3,550 3,500 3.660 3,550 42.2 17.8 20.0 1960-1970. 33 1970-1980 26 20 S0UKCES: Col. 1 Col. 2: Cols. 3 and 4: Col. 5 : Col. 6 : 1890-1950. U. S. Bureau of the Census. Statistical Abstract of the United States, 1951. Washington, U. S. Govt. Print. Off , p. 31. (Table 38) 1960-1980. Projected— "reasonable lower limit." Irend fitted to population as enumerated. Items in these columns are the differences between the successive items of columns 1 and 2. respectively. e»S e '" P°P ulati , on . as enumerated for any decade expressed as a per- centage of the population enumerated at the beginning of that decade the r nm, ( !,, 1 'J- Pni I" Ia, 1 10 'll ren u d for any decade expressed as a percentage of the population trend at the beginning of that decade. who in 1950 were 10 years of age and older. One third was natural increase and immigration of chil- dren who in 1950 were under 10 years of age. Thus, immigration is seen to be the most important element of growth in California's population. Immigration is a highly variable factor. In the decade ending in 1950, nearly 2,500,000 persons immigrated to California.' The previous decade less than 1,000,000 came. In the post-World War I years, 1920-1930, 1,750,000 immi- grated to California, whereas during the decade pre- vious to that only a little more than 750,000 were in- cluded in the estimated immigration. These highly variable figures of immigration emphasize the pre- carious nature of population projections especially for a state that is growing as rapidly as is California. The projection of Table 2, illustrated in Figure 1C, is one of four which have been made for California.' Historical numbers of population of California at the end of each decade are shown from 1930-1950, in- clusive, together with projections to 1980. California population was projected on the basis of assumptions of four rates of immigration. The projection presented in Table 2 has been selected from the above four projections for use in projecting the California crop pattern because the assumptions of immigration for this projection seem to be the most reasonable among those used. These assumptions are stated below in the discussion of net effective immigration. Although no attempt has been made to project minor variations in population from year to year or deviations from the normal at any census period, the extreme variation during the decade 1930-1940 and again in 1940-1950 will undoubtedly be reflected in a major way at the turn of the next generation. The projection presented in Table 2 and Figure 1C ac- cordingly contains adjusted immigration figures based upon expected economic effects of important changes in the age distribution of both California and the United States. The major elements in the method of population projection that has been used in the current studies may be enumerated as follows: 1. Survivors of the population 10 years of age and over at the end of each decade who were living in California at the beginning of the decade. 2. Net effective immigration. 3. Child population under 10 years of age living in California at the end of each decade. The sum of these three elements constitutes the total population in the state at the end of any given decade. The use of t\\^ above elements has been dictated by the availability of information and the form in which it is available. The methods by which each of these elements has been estimated historically and projected were presented in detail in a publication by the State Division of Water Resources, issued in 1930. 8 Exten- sion of these earlier estimates up to 1950 with revised projections to 1980 has been made in connection with the current studies. Survivors at the End of a Decade. The survivors at the end of a decade of those of the population who were living in California at the beginning of the decade are all 10 years of age and older. Some of them are living in California while others have moved away. Those who have moved away represent a very small part of the total of the survivors. Separation of estimates of that portion of the survivors who have emigrated from estimates of those who have remained is very difficult. Therefore, estimates of the number of survivors at the end of the decade of those who were living in California at the beginning of the decade contain an unknown but small percentage of the total who have emigrated. This over-estimation is compensated for in the next step. Net Effective Immigration. Net effective immi- gration during any decade, as used here, is equal « Weeks, David. '•Permissible Economic Rates of Irrigation De- velopment in California." State Department of Public Works Publications of the Division of Water Resources, 1930* APPENDIX A 237 to the difference between the California population 10 years and older at the end of that decade and the number of survivors of the total population living in California at the beginning of that decade. It is short of being what is implied in the term net effective immigration by an amount equal to the survivors of the population living in California at the beginning of the decade and who have emigrated during the decade. The amount of this shortage is exactly equal to the excess indicated above in estimates of the num- ber of survivors. This excess is the number of sur- vivors of those who were living in California at the beginning of the decade and have moved away. The sum of the number of survivors at the end of the decade of those who were living in California at the beginning of the decade, plus the California net effective immigration as defined here, represents the population 10 years of age and older at the end of a decade. Thus, the deficiencies in the numbers of survivors at the end of the decade and the excess in the net effective immigration, each equal to the survivors who have emigrated, exactly compensate each other. Because of this compensation and the fact that the emigration from California is small com- pared with immigration, net effective immigration as here calculated and projected becomes a useful though not an absolute measure of net immigration. Projections of net effective immigration to Cali- fornia have been made on the assumption that it is closely related to the increase in United States popu- lation. Of course, it is also related to economic condi- tions in the state of origin and opportunities for a means of livelihood in California. In the absence of more satisfactory measures of these respective eco- nomic opportunities, which are both undoubtedly reflected in historical trends of immigration, projec- tions of net effective immigration have been made on the basis of 4 different assumptions of the ratio of net effective immigration to projected increase in United States population 10 years of age and over. The projected ratio of net effective immigration to projected increase in United States population 10 years of age and over which has constituted a basic assumption of the projection of California population presented in Table 2 is more than a graphical extra- polation of the historical trend of this ratio. This assumption is that the high ratio, 22.8 per cent, the actual rate during the decade 1940-1950, will have declined to 18.7 per cent in the decade 1950-1960 and to 13.4 per cent in the decade 1960-1970 but will rebound to 16 per cent in the decade 1970-1980. This change in the direction of trend of this ratio is based upon an opinion that the upsurge in the number of births expected in the decade 1970-1980 will react upon the economic situation to the extent that the rate of immigration will be stimulated. The expected upsurge in the decade mentioned would result from the fact that, early in the decade 1970-1980, the sur- vivors of the 14,500,000 female children under 10 years of age in the 1950 United States population will have reached the ages of maximum fecundity. This age group in the 1950 population is 35 per cent greater than the group 10-19 years of age in the same population. After allowing for mortality, this group is now and will continue to be of great importance as it moves through the different phases of its growth. Thus, it will be in the late 1960 's and early 1970's when the present "upsurge" in population which began in the 1940's will again make itself felt as another upsurge in the next generation. These con- siderations have made it seem necessary to depart somewhat from the smooth trend which would have resulted from a purely geometrical extrapolation. Projection of the Child Population. As indicated above, the child population under 10 years of age living in California at the end of each decade is the third and last element entering into the projected California population. This child population under 10 years of age represents those who (a) have immi- grated during a specific decade and (b) were born in California. In either case their number reflects changes in fertility rates and, to some extent, survival rates. The use of this kind of an element which is equivalent to a crude birth rate is justified, as indicated above, by the high likelihod of error in the immigration rate. The use of highly refined birth rates would be in- consistent with the necessarily rough projection of immigration rates. The total child population has been projected indirectly in the ratio of the popula- tion 10 years of age and over to total population. This ratio has been projected to 1980 on the basis of an assumption of a slightly declining crude birth rate, notwithstanding the expected upsurge in the number of births indicated above. Population and the Crop Pattern The total acreage of California field crops irrigated has shown a close relationship in its expansion to the rate of increase of California population. This is a logical consequence of the expanding livestock markets on the Pacific Coast and of the recently demonstrated advantages of California compared with competing areas in the production of irrigated field crops. The close relationship observed over many decades between the rate of increase of the California irrigated field crop acreage and the rate of increase of California population growth suggests the projected rate of in- crease of the California population as the best indi- cator of the future rate of increase of the total irri- gated field crop acreage. California commercial truck crops, on the other hand, have a nationwide market, and for more than 20 vears the rate of increase of their acreage has closely 238 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA paralleled the rate of increase of the United States population. The acreage of these crops as a whole, therefore, most of which are irrigated, should be ex- pected to increase at the projected rate of increase of the United States population. The market for California orchard and vineyard crops also is largely nationwide, and to some extent the products of orchards and vineyards enter world trade channels. It would be expected, therefore, that the rate of increase of the total acreage of orchards and vineyards combined would approximate the rate of increase of United States population more closely than it would approximate the rate of increase of California population. The historical record of the orchard and vineyard acreage of California, however, does not conform to this expectation. An indirect method of projection based upon United States popu- lation growth rates and orchard and vineyard crop production has been applied and described at a later point. Consequences of Under- or Overestimates of Future Population Although it will be observed that the percentage distribution of the different crops within the Cali- fornia crop pattern is expected to go through a grad- ual change during the coming decades, the change is not so rapid as to create great concern over the con- sequences of error in judgment in the projection of the rate of population growth. The projections which have been made to 1980 in the present use of poptda- tion growth rates constitute a preliminary assumption only, on the basis of which the nature of changes in the crop pattern can be observed. If the poptdation projection for 1980, therefore, should not be attained until 1990 or 2000, the changes in the relative propor- tions of the projected crop patterns accompanying such an extension of time for the attainment of a given population would not materially change the relative proportion of the different types of crops within the pattern. Thus, as was stated at the outset; high precision in population projection is not essential for obtaining a fairly reasonable apportionment of the different acreages of crops within the total. CALIFORNIA CROP PATTERN OF THE LATE 1940's As previously stated, the California crop pattern for 1946-1950 constitutes the starting point from which projections have been made. Also, it has been stated that three major sources of information have constituted the basis upon which trends of acreage of different groups of crops have been extended into the future. A Major Part As Indicator of the Whole The 1946-1950 crop pattern, insofar as it is capable of description by information from all 3 of the above sources, is presented in Table 3. In view of the gaps and limitations mentioned earlier, projections have been made on the basis of historical analyses of a major portion but not all of the crop acreages shown in Table 3. It has been assumed that the percentage rates of increase estimated for this incomplete total may be applied to the entire acreage for projection by a close examination of Table 3. The first part of the table provides acreage statistics for 3 major groups of California crops : orchard and vineyard, commercial truck crops including potatoes, and field crops. It will be noticed that the orchard and vineyard acreage is subdivided into 4 subgroups : deciduous tree fruits, vineyard, citrus and miscellaneous sub- tropical fruits, and nuts. It also will be noticed that the field crops are further subdivided into major field crops (Group I) and miscellaneous field crops (Group II). The total acreages irrigated and nonirrigated as reported by the census for 1949 and by the Crop Reporting Service as a 1946-1949 average are 7,948,- 000 and 8,398,000, respectively. In general, these acreages represent the average degree of undernumer- ation by the census when measured by the estimates of the Crop Reporting Service. It must be observed, how- ever, that the time periods of these 2 figures are not exactly the same. Both of these estimates, moreover, do not include a number of additional crops which are reported on a noncomparable basis. On the other hand, a certain amount of duplicated acreage is included, representing interplanting and double cropping, mak- ing possible the harvest of more than 1 crop from the same land in a given year. The 1950 census made an attempt at elimination of this duplicated acreage in the reporting of summaries of cropland harvested. Census reports, after deducting duplicated acreage, give a total acreage of cropland harvested for 1949 of 7,957,000 acres, representing 57.8 per cent of the total cropland area of 13,765,000 as estimated by the 1950 census for the year 1949. Irrigated Acreages Historical trends in the acreages of irrigated Cali- fornia crops projected to an assumed stage of full development provide percentage increases to be ap- plied to the irrigated acreages of the 1946-1950 crop pattern. Percentages Irrigated. Table 3, in addition to showing acreages and irrigated acreages, indicates also the percentages irrigated for the different groups of crops including bearing and nonbearing acreages combined of the orchard and vineyard crops. Of the total cropland harvested, including duplicated acreage and excluding a small acreage of noncom- parable items, 65.3 per cent was irrigated in 1949 according to 1950 census acreages irrigated and total. Of the total orchard and vineyard acreage, 78.6 per cent was irrigated in 1949. APPENDIX A 239 For observing historical trends, however, informa- tion on bearing acreages is more complete. The per- centages irrigated of the bearing acreages of orchard and vineyard and harvested acreages of other Cali- fornia crops, as calculated from the census acreages, total and irrigated, and presented in Table 4, have been applied to the acreages of crops harvested re- ported by the Crop Reporting Service for the pur- pose of obtaining an approximate estimate of the trend in irrigated acreage of individual crops and TABLE 3 CALIFORNIA CROP ACREAGES, 1949, TOTAL AND IRRIGATED Total acreage Irrigated acreage Percentage irrigated Crop and crop group Census, 1949 Crop Reporting Service, 1946-1949 Census, 1949 Division of Water Resources Survey Census, 1949 Division of Water Resources Survey and California Crop Reporting Service 1 2 3 4 5 6 thousands of acres Orchard and vineyard 428 489 223 331 471 544 238 337 288 393 145 331 482 485 128 371 67.4 80.4 64.8 100.0 Vineyard _ _ _ _ _ . 89.2 53.8 Citrus and miscellaneous 1,471 100 9 517 1,590 112 11 596 1,157 96 9 512 1,466 78.6 96. 0cscrt uiva TOTAL_ Acres 250,000 350,000 400,000 1,250,000 1,500,000 150,000 200,000 4.100,000 SOURCE: California Division of Water Resources. Unpublished material, July 17, 1952. Price Controls in Relation to Long-Term Acreage Trends Most of the great volume of discussion concerning farm price control policy has generally avoided the difficult question of their probable effects upon long- term acreage trends. An appraisal of the foregoing projections in the light of price controls may be necessary. It will be difficult for many to reconcile the huge surpluses of stored crops still in the hands of the Commodity Credit Corporation with the rapidly rising trends in acreage projected above for some of the California crops. Price stabilization has been sought through the use of several devices. Among the more important of these devices may be enumerated the following: (1) pay- ments or grants-in-aid to farmers, (2) nonrecourse loans, (3) acreage allotments, (4) marketing quotas (domestic and international), (5) establishment of a scale of prices for or a set of regulations of the 18 Personal letter to David Weeks from William L. Berry, State Department of Public Works, Sacramento, California, July 17, 1952. 254 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA movement of different classes of the commodity (mar- ket agreement and order programs), and (6) tariffs. In addition to the above devices are the various marketing activities carried on under the broad powers granted the Commodity Credit Corporation including various types and forms of subsidy pay- ments, multiple price systems, commodity diversions, etc. Some of the above measures tend to expand the acreage devoted to the production of the affected com- modities while others tend to contract acreage. Recent legislation has sought combinations of devices for optimum regulation of acreage, production, price, and income. The complex problems, however, of competi- tion between crops for the use of the land and be- tween different areas for the different crops have not been solved. A definition and brief description of the different control devices follow. Payments or Grants-in-Aid to Farmers. Payments directly to farmers are made in the interests of con- servation and with a view to insuring to the farmer a just share of the national production required for domestic consumption and for export. Such payments are made (1) for the performance of farm practices that are presumed to restore soil productivity and prevent erosion, (2) to change the use of land in the interests of soil conservation and as a means of indi- rect income stabilization, and (3) as payments in direct support of farm prices and income. In recent years the payments made for farm prac- tices and for changes in land utilization have become more truly a conservation program. They had been introduced originally to avoid the legal difficulties of acreage reduction as a means of price control. They have lost much of their earlier significance, however, in carrying out the price stabilization policy stated and implied in the Soil Conservation and Domestic Allotment Act. "Payments or Grants-in-Aid" di- rectly to farmers currently remain the major means of effectuating the Agricultural Conservation Pro- gram of the Production and Marketing Administra- tion. Although the existing price-support legislation still provides for price-support payments, other de- vices have in general taken the place of such pay- ments in the broader objective of price support. "Conditional Payments" directly to farmers, how- ever, still constitute an important feature of the Sugar Act of 1948. Nonrecourse Loans. In lieu of payments for per- formance and of direct purchase of commodities from the producer, the Commodity Credit Corporation is empowered to make loans to the producer on stored and sealed commodities as collateral. Sale of the col- lateral, even at a price below the amount of the loan by the Corporation for the repayment of the loan, does not obligate the producer to make up the loss. On the other hand, if the price rises above the value of the loan, it can be paid and the producer may receive the higher market price for his product. The loan thus becomes a means of price support for "basic" commodities, for designated nonbasic com- modities, and, if certain criteria are fulfilled, for other "nonbasic" commodities. Basic commodities of importance to California are wheat, cotton, and rice. Nonbasic commodities of importance to California include wool, Irish potatoes, and certain dairy prod- ucts. Sugar beets are covered by the special Sugar Act of 1948. Acreage Allotments An acreage allotment is an acreage determined in advance as that required to produce the annual supply necessary for the national domestic consumption and export of a given commodity and adopted by those in administrative responsibility as a basis of alloca- tion among the states, counties, and farms. The cri- teria for making these allocations have varied from time to time according to the commodity and the particular act under which the allotment has been administered. Enforcement usually is by means of a price penalty for violation of the allotment. Acreage allotments have been a part of the Soil Conservation and Domestic Allotment Act and of the Agricultural Adjustment Act of 1938. Their use has been broadened by the Agricultural Act of 1949. They have been introduced with the view to serving two purposes in general: (1) as a direct means of main- taining an adequate supply of agricultural commodi- ties from domestic production adequate to meet the domestic and foreign demand at prices fair both to producers and consumers and (2) as a means of administering and supplementing marketing quotas designed for the same purpose. Marketing Quotas. A farm marketing quota is a quantity of a given agricultural commodity deter- mined in advance as that required to supply the nation 's domestic consumption and export needs with- out excess and adopted by those in administrative responsibility as a basis of determining the amounts to be allocated for marketing among the states, coun- ties, and farms. The criteria for determining these quotas have varied from time to time according to the commodity and particular act under which the quota has been administered. Enforcement is by means of a price penalty for violation of the quota. Marketing quotas have been promulgated as have acreage allotments as a direct means of maintaining a continuous and stable supply of agricultural com- modities at prices assumed to be fair to both pro- ducers and consumers. Furthermore, marketing quotas have been made a condition, acceptance of which by producers has been a requirement for a given level of price support. APPENDIX A 255 Marketing Agreements. A marketing agreement may be either state or federal. In California it is a contract entered into voluntarily between either the State Department of Agriculture or the United States Secretary of Agriculture on the one hand and handlers of the commodity on the other. While surplus control and price stabilization are major objectives of the marketing agreement, its functions are to regulate both quantity and quality of a commodity reaching the market. The marketing' agreement applies to a limited area. Marketing Orders. Marketing orders like market- ing agreements apply to limited areas. They may or may not establish minimum prices. Their major dif- ference from a marketing agreement is that they apply by law to all of the handlers of the commodity within the area to which they apply. The marketing- order and marketing agreement may both be features of the same program. The California Milk Marketing- Act has many features similar to those of a mar- keting order. Other Devices. A number of other activities such as purchase and diversion of surpluses, subsidy pay- ments to exporters, consumer subsidies or price dif- ferentials, and tariffs all seek to improve producers' incomes. Price Stabilization and Crop Acreage Trends. Of the above devices applied for the purpose of stabiliz- ing and improving farm income, the acreage allotment and the marketing quota are the only ones that limit acreage expansion. The others may or may not be combined with marketing quotas, acreage allotments, or both for the purpose of preventing runaway acre- age expansion in response to improved farm income. It is not the purpose here to express an opinion re- garding the merits of the legislation which embodies various combinations of the above devices as applied to the different crops. The basic question here is : How arc the long-term projections presented in Table 6 likely to be affected by different possible lines of political action? The three most likely alternative pol- icies expressed in broad terms are assumed as follows : 1. Retention of the main body of price stabilization legislation with further refinements in the di- rection of marketing quotas and/or acreage allotments, combined with each price-support measure. 2. Gradual removal of all price stabilization measures. 3. Expansion of voluntary types of control meas- ures within the various agricultural industries. Effective price stabilization, it would seem, would tend to concern itself with the variations about the trend and not with the trend itself. Any attempt to hold down a natural trend by rigid control measures would seem to be likely to result ultimately in a forced adjustment. A tentative assumption can be made, therefore, that long-term national trends will be the same with and without price stabilization legis- lation. Some qualification of the above assumption must be made, however, in regard to trends in California com- pared with national trends. The state acreage allot- ment for any basic commodity will determine its share in the national allotment. There is some pos- sibility that adherence to existing formulae may prevent natural shifts in production to areas in Cali- fornia which recently have demonstrated a superior advantage with respect to quality of product and economy of production. Retention of existing price stabilization legislation, therefore, may cause the acre- age of a basic commodity like cotton to fall below the projected trend and to approach more nearly a rate of increase in accord with projected United States population increase modified by trends in per-capita consumption and projected demand for export. The 1954 projected trend for cotton, however, is well below the 936,408 acres approved January 7, 1954, for allot- ment to California by the United States Senate Com- mittee on Agriculture. It would seem that, in the light of uncertainty of future legislation, a recalculation of the cotton projection would not be justified. The ele- ment of uncertainty, however, thus injected by politi- cal action and competition between the states cannot be entirely ignored. The other two "basic" crops of importance to Cali- fornia are rice and wheat. Each like cotton is affected by the hazards of an export market. In the legislation providing price support for these crops, there are provisions for trend, but each like cotton must share any increase in trend with the other states. In fact, the small percentage increase allowed for trend in most of the acts is generally allocated to the small- scale producers of other states. The nonbasic crops, on the other hand, while sub- ject in many cases to the acceptance of marketing- quotas and acreage allotments as conditions for price support, either represent crops which are highly spe- cialized in California where a large part of the total national production is centered or are feed crops not affected directly by price-support programs. For most of these crop groups, trend values should not be ex- pected to be greatly changed by price stabilization legislation. Some of them seek price stabilization through marketing agreements which apply to limited areas. Trend values should not be affected by such localized price-support measures, especially if accom- panied by marketing quotas. Many of the feed crops are affected indirectly through various state legisla- tion affecting the dairy industry. These also have local or regional significance but should not affect long-term trends. 256 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA The general conclusions with respect to this imme- diate question of the probable effect of price stabiliza- tion upon long-term acreage trends are : ( 1 ) there is no indication that there will be sufficient certainty of legislation which will affect trends which would war- rant making allowance for it; (2) in general, price stabilization if accomplished should affect variations from the trend more than the trend itself; and (3) in relation to some basic crops, a long continued acreage allotment policy, such as that implied by existing legislation, could affect the long-term trend in Cali- fornia's share in the national allotment and thereby affect the trend as projected. CONCLUSIONS Conclusions may be drawn with respect to the California projected statewide crop pattern by again calling attention to Table 6 which itself is a one-page summary of the entire study. In referring to the per- centage distribution of that table, however, it must be emphasized again that, although it was tentatively assumed to be applicable for 1980, it may better be considered as applicable to a stage of development which is expected to be reached as California ap- ! proaches the full utilization under irrigation of her irrigable area. That time may be 1980 or before or after that time. It represents not a specific date but a given stage of agricultural development. This stage in i agricultural development also represents an impor- tant stage in the development of California's water resources. Although the crop pattern is presented as that which may be assumed for an initial stage of full development, the water requirement for that crop pat- tern is assumed to be the same as that for a later stage that has been referred to as a stage of "ultimate development. ' ' """ EXTRAPOLATED 1975- 1960 "MEC OF M IUM PROJECTION" ftGOOO AND SIEGEL APRIL. 1951 CENSUS ENUMERATION 1910- I9S0 1910 1920 1930 1940 I9S0 I960 1970 YEAR Fig. IA. POPULATION OF THE UNITED STATES (including military forces overseas) 1 ! 1 1 1 CENSUS ENUMERATION \ 1910 - 1950 ^ TREND, 1910-1950 ^ ^ AS PROJECTED EXTRAPOLATEO 1975-1980 PROJECTED TREND — ■ fi 1910 1920 1930 1940 1950 I960 1970 Fig. IB. PERCENTAGE INCREASE PER DECADE OF UNITED STATES POPULATION ^ -" PROJECTED REASONABE . 1950- _OWER I960 c ENSL S EN 1860- UMEF 1950 AT 10 M 1920 1940 Fig. IC. POPULATION OF CALIFORNIA PERCENTAGE INCREASE OF POPULATION AS ENUMERATED Fig. ID. PERCENTAGE INCREASE OF CALIFORNIA POPULATION OVER THE POPULATION TEN YEARS EARLIER PROJECTED POPULATION OF UNITED STATES AND CALIFORNIA DIVISION OF WATER RESOURCES L- — . TOTAL ^~ ? "" ■' ^< IRRIGATED 1930 1940 YEAR Fig. 2A. CITRUS FRUITS TOTAL — . — " IRRIGATED 1930 1940 Fig. 2B. NUT CROPS / "">. TO "AL / / s > — , > / / •-. / / 1RR GATE D ~ — / ' 1920 1930 1940 1950 Fig. 2C. DECIDUOUS TREE FRUITS TO" - AL X * / '"N J / 1 ^ ■ — IRR GATE D \ / / / / / / J 1930 1940 YEAR Fig. 2D. VINEYARD ALL IRRIGATED . 1 1 1930 1940 YEAR Fig 2E. RICE 1200 800 A M \ 400 / V- J t \ J ALL IRRIGATED 1 1 1 1920 1930 1940 Fig. 2F COTTON _L // \ s/aV TOTAL v ; V ~K\ y/ K/ 600 y ^/ IRRIGATED S 1920 1930 1940 Fig. 2G. ALFALFA i TOTAL -^"^ ^ V / V V nst^ IRRIGATED 1 1 V_/ 1930 1940 Fig. 2H. SUGAR BEETS k A V TO! AL 7 \\ *\ \ s ./ V \ .VI V v -. s" IRR GATE 3 v>- Fig. 21. CORN, SORGHUMS, HOPS AND FLAX 400 \ TOTAL / \ \ V "*\ A 200 w ' ' \ / -y S/\ \ y >,• •"" r s \- IRRIGATED 1920 1930 1940 YEAR Fig. 2J. BEANS, GREEN AND DRY TOTAL _ IRRIGATED 1 l 1920 1930 1940 1950 Fig. 2K. EXTENSIVE HAY CROPS (WILD GRAIN AND OTHER TAME HAY EXCLUDING ALFALFA) < 3000 \ ; \ j "V S \f" V 1 •^ -- - — J \J TOTAL V \ V V r~~' v," v" "-" —^ \r — /'^ IRRIGATED -\/ 1930 1940 YEAR Fig. 2L SMALL GRAINS TOTAL AND IRRIGATED ACREAGE OF CALIFORNIA CROPS DIVISION OF WATER RESOURCES — 2000 , / \ ,r - — . A '\ d r V V. ^ ^ -\ 7*- -j 1000 * rf =>x \ / \ / 1940 1950 Fig. 3C. CITRUS FRUIT 1940 1950 YEAR Fig. 3D. NUT CROP CALIFORNIA FRUIT, GRAPE AND NUT PRODUCTION DIVISION OF WATER RESOURCES PLATE A4 800 — — ' L — ' GOO 400 1940 195 TEAR Fig. 4A TRUCK CROPS Fig 4B FIELD CROPS 1940 1950 FIG. 4C. ALFALFA 1940 1950 YEAR Fig. 4D. COTTON 400 _ J- — - — 300 500 " .— "- 500 1500 ___^. -~ tooo 500 A l ^ «— ■ - ^^ 1940 1950 YEAR Fig 4E. RICE ^ 3000 ,^- -" 2000 1000 ^ ^ r , ^-—_ \^ 1930 1940 1950 I960 Fig 4F MISCELLANEOUS FIELD CROPS -- 300 200 —C — 100 1940 1950 Fig 4G BEANS --' 300 200 « V V' 100 :/ V —T" Vy > Fig 41. MISCELLANEOUS, INTENSIVE FIELD CROPS 600 S 200 ** 800 400 1930 1940 1950 I960 Fig. 4J. SMALL GRAIN CROPS *>* 600 200 1940 1950 YEAR Fig. 4K. EXTENSIVE HAY CROPS IRRGATEO HARVESTED ACREAGE TREND OF IRRIGATED HARVESTED ACREAGE PROJECTED TREND Fig 4H SUGAR BEETS IRRIGATED HARVESTED ACREAGE OF CALIFORNIA CROPS DIVISION OF WATER RESOURCES APPENDIX B DIRECTORY OF WATER SERVICE AGENCIES IN CALIFORNIA (257) TABLE OF CONTENTS DIRECTORY OF WATER SERVICE AGENCIES IN CALIFORNIA Page Introduction - 259 Commercial Water Companies - 259 Mutual Water Companies - 259 Public Water Districts— - 259 Municipal Waterworks - 261 Directory of Water Service Agencies in Cali- fornia - 261 North Coastal Area - 262 Del Norte County - 262 Humboldt County - 262 Marin County - 262 Mendocino County - 262 Modoc County - 262 Siskiyou County - 262 Sonoma County — 262 Trinity County 263 San Francisco Bay Area - 264 Alameda County - 264 Contra Costa County 264 Marin County - 264 Napa County - 264 San Francisco County - 264 San Mateo County - 264 Santa Clara County - 265 Solano County 265 Sonoma County 265 Central Coastal Area - 266 Monterey County - 266 San Benito County - 266 San Luis Obispo County 266 Santa Barbara County 266 Santa Clara County__ - 267 Santa Cruz County 267 South Coastal Area 268 Los Angeles County 268 Orange County 271 Riverside County 272 San Bernardino County 273 San Diego County 275 Ventura County 276 Central Valley Area 278 Alameda County 278 Amador County 278 Butte County 278 Calaveras County 278 Colusa County 278 Page Contra Costa County 278 El Dorado County 279 Fresno County 279. Glenn County 280 Kern County 280. Kings County 281 Lake County 281, Lassen County 281 Madera County 281 Mariposa County 282 Merced County 282 Modoc County 282 Napa County - 282 Nevada County 282 I Placer County 282 • Plumas County 282 Sacramento County 282 San Joaquin County 283 Shasta County 284 : Sierra County 284 ' Siskiyou County 284 ' Solano County 284 Stanislaus County 284 Sutter County 285 Tehama County ,. 285 Tulare County 285 Tuolumne County 286 Yolo County 286 Yuba County 287 Lahontan Area 288 El Dorado County 288 j Inyo County - 288 Kern County 288 Lassen County 288 Los Angeles County 288 Modoc County 288 I Mono County 288 Nevada County 288 -■ Placer County 288 i San Bernardino County 289 Colorado Desert Area 290 Imperial County 290 Riverside County 290 San Bernardino County 290 San Diepo Countv 290 ( 258 ) APPENDIX B 259 DIRECTORY OF WATER SERVICE AGENCIES IN CALIFORNIA INTRODUCTION One of the major factors contributing to the phe- nomenal growth of California has been the favorable [political climate for local community water develop- jment. This environment, expressed through laws and (policies of the State Government, has permitted the [formation of local organizations to cope with and ^resolve water problems, and to meet as they occurred [the many municipal, industrial, and agricultural water demands. Presently there are more than 2,500 such organizatons in the State. As a part of the investigation of present water utilization in California, a list was compiled of the "agencies which serve, distribute, or sell water for ,'domestic, irrigation, or other uses. This directory is presented hereinafter in tabular form. Introductory to the directory, there follows a brief description of the principal classes and types of local | community water service agencies in California. There tare two principal types of such agencies, privately owned and public. The privately owned agencies may, [in turn, be divided into two general classes, commer- i cial water companies and mutual water companies. i The principal classes of publicly owned agencies are public water districts and municipal waterworks. Commercial Water Companies Commercial water companies are organized for the purpose of building and operating waterworks for the profit of persons who will provide the capital for and own the systems. They differ from mutual J water companies and public agencies in that both of , the latter are nonprofit cooperative enterprises under j local ownership and control. Ownership of the assets of a commercial water company may be held by per- ; sons who live outside of the water service area. Such j companies are usually incorporated, although an ! individual may engage in public utility service of ; water. Most commercial water companies in California : operate under the jurisdiction of the State Public Utilities Commission, and must serve water to all applicants within their service areas, as specified in certificates of convenience issued by the Public Utili- ties Commission. Mutual Water Companies Mutual water companies, sometimes called "co- operatives," are private associations of people, organ- ized for the purpose of providing water at cost, primarily for the use of their members. Such com- panies are voluntary, nonprofit enterprises, and are controlled by their members or stockholders. They have no obligation to serve water to any but their members and stockholders. This contrasts with the obligations of water districts and commercial com- panies, under which service must be extended to all consumers within such agency's service area if water is available. Mutual water companies may or may not be incorporated, and do not come within the jurisdic- tion of the Public Utilities Commission. Public Water Districts Early in the statehood of California the people recognized that privately owned and operated water service organizations could not cope with all the water problems that were developing. Through their Legis- lature, therefore, they enacted the first of many laws providing for public districts to accomplish certain desirable purposes. It is notable that nearly all public water districts, unlike mutually owned enterprises, have the power of assessment of the lands of the dis- tricts and of eminent domain. The first of the water district laws was the Reclamation District Act of 1867. The first law authorizing formation of irrigation districts was enacted by the Legislature in 1872. How- ever, the Wright Act of 1877 has formed the basis for virtually all irrigation district legislation subse- quently enacted in California. Since that time, as new or more pressing water problems arose requiring public action, the Legislature has passed many acts authorizing formation of different types of districts to meet different circumstances. There are at present two principal methods in this State of forming water districts. One is the enactment by the Legislature of a general act, under which any number of districts may be formed in accordance with a procedure set forth in the act. The other method is by a special act of the Legislature creating a partic- ular district and prescribing its powers. Under the general water district acts, there are specific provi- sions requiring notice and hearing of petitions for formation, which for the most part are conducted by county boards of supervisors. Under the second method, notice and hearing are afforded by the legis- lative process, whereby the authorizing bills are heard in committee and on the floor of the Legislature. California statutes presently authorize the forma- tion of more than 30 types of districts relating to the development, conservation, use, disposal, and avoid- ance of water, and most of these districts may provide water service. There follows a list of general water district acts, together with the year of the original authorizing legislation. Community Services Districts (1951) County Recreation Districts (1931) 260 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA County Water Authorities (1943) County Water Districts (1913) County Waterworks Districts (1913) Drainage Districts (1885) Drainage Districts (1903) Drainage Districts (1919) Flood Control and Flood Water Conservation Districts (1931) Irrigation Districts (1897) Levee Districts (1905) Metropolitan Water Districts (1927) Municipal Utility Districts (1921) Municipal Water Districts (1911) Municipal Water Districts (1935) Protection Districts (1880) Protection Districts (1895) Protection Districts (1907) Public Utility Districts (1921) Reclamation Districts (1867) Resort Districts (1931) Storm Drain Maintenance Districts (1937) Storm Water Districts ( 1909 ) , Water Districts (1913) Water Conservation Districts (1927) Water Conservation Districts (1931) Water Replenishment Districts (1955) Water Storage Districts (1921) Water Storage and Conservation Districts (1941) Most but not all of the foregoing listed acts have been used by interested groups to form water dis- tricts. The purposes, powers, restrictions, and privi- leges, which vary with each act, are briefly described and compared in a periodic publication of the Divi- sion of Water Resources entitled "General Compari- son of California Water District Acts." In addition to the water districts formed pursuant to the foregoing general district acts, more than 30 districts have been formed under special acts of the Legislature. The Legislature has constitutional authority to organize taxation districts with bound- aries defined in the legislative act, without submitting the question to a vote of property owners within the area. Most of such special water districts are county- wide in area, and may be regarded as a natural out- growth of the local district organization movement as the water problems became more and more com- plex. Inasmuch as most of these districts have been created of recent years, only a few to date have ac- tively entered into water development activities. The following list is indicative of the districts formed under special acts, whose powers include the develop- ment, disposal, and/or sale of water. The year shown for each district is that in which it was created by the Legislature. These likewise are briefly described and compared in the publication cited in the preceding paragraph. Alameda County Flood Control and Water Con- servation District (1949) American River Flood Control District (1927) Avenal Community Services District (1955) Brisbane County Water District (1950) Contra Costa County Flood Control and Water Conservation District (1951) Contra Costa County Storm Drainage District (1953) Del Norte County Flood Control District (1955) Donner Summit Public Utility District (1950) Humboldt County Flood Control District (1945) Kings River Conservation District (1951) Lake County Flood Control and Water Conserva- tion District (1951) Los Angeles County Flood Control District (1915) Marin County Flood Control and Water Con- servation District (1953) Mendocino County Flood Control and Water Conservation District (1949) Montalvo Municipal Improvement District (1955) Monterey County Flood Control and Water Con- servation District (1947) Morrison Creek Flood Control District (1953) Napa County Flood Control and Water Con- servation District (1951) Olivehurst Public Utility District (1950) Orange County Flood Control District (1927) Orange County Water District (1933) Riverside County Flood Control and Water Con- servation District (1945) Sacramento County Water Agency (1952) San Benito County Water Conservation and Flood Control District (1953) San Bernardino County Flood Control District (1939) San Diego County Flood Control District (1945) San Luis Obispo County Flood Control and Water Conservation District (1945) Santa Barbara County Flood Control and Water Conservation District (1955) Santa Barbara County Water Agency (1945) Santa Clara County Flood Control and Water Conservation District (1951) Santa Cruz County Flood Control and Water Conservation District (1955) Solano County Flood Control and Water Con- servation District (1951) Sonoma County Flood Control and Water Con- servation District (1949) Vallejo Sanitation and Flood Control District (1952) Ventura County Flood Control District (1944) Yolo County Flood Control and Water Conserva- tion District (1951) APPENDIX B 261 Municipal Waterworks One of the major classes of publicly owned water service agencies in California consists of municipally owned waterworks, which, in general, serve water within the municipal boundaries. Approximately 200 ! cities in California now own and operate their own waterworks. DIRECTORY OF WATER SERVICE AGENCIES IN CALIFORNIA The following tabulation of water service agencies in California presents the data by counties in each hydrographie area. Information on the number of domestic consumers and on the number of irrigated acres, as well as the approximate location of the service area of each agency, is included in the tabula- tion. The period during which this information was collected was from 1950 through 1954. Inasmuch as there is a continuing process of forma- tion of private and public water service agencies, and also a process of dissolution or annexation of such agencies, the directory, although the most complete and comprehensive known to have been made to date, is not warranted to include all such agencies that may exist in California. 10—99801 262 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA WATER SERVICE AGENCIES, NORTH COASTAL AREA Name of water agency Del Norte County Commercial Water Companies Crescent City Water Company Hunter Water Company Klamath Glen Subdivision Water Service Klamath Water Company McBeth Acres Water System Smith River Water Service Mutual Water Companies Gasquet Mutual Water Company Humboldt County Municipal Waterworks Areata Blue Lake Eureka Fortuna Trinidad Commercial Water Companies Benbow Water Company Camp ton Heights Water Service Fields Landing Water Works Francis Land and Water Company _ Garberville Water Company, Inc.-_ Humboldt Hill Water Service Loleta Water Works Myers Water Works Phillipsville Water Company Red way Water Company Rio Dell Water System Riverside Water Works Rohnerville Water Works Weott Water Company Willow Creek Water Works Mutual Water Companies Areata Airport Water Supply Big Lagoon County Water Supply Carlotta Water Supply East Highway Water Company Fickle Hill Water Supply Fort Seward Water Supply Hagwood's Orick Water Supply King Salmon Mutual Water Company Korbel Water Supply Orick Water Company Port Kenyon Water Supply Samoa Water Supply Scotia Water Supply Marin County Commercial Water Companies Coast Springs Water Company. Mendocino County Municipal Waterworks Fort Bragg Ukiah Commercial Water Companies Brown's Water Works Dos Rios Water Works Pacific Gas and Electric Company ... Point Arena Water Works Rogina Water Company Mutual Water Companies Caspar Lumber Company Laytonville Mutual Water Company Oak Knolls Mutual Water Company . County Water Districts Willow County Water District Round Valley County Water District- Location, in or near Area irri- gated, Crescent City. Crescent City_ Klamath Klamath Klamath Smith River. Crescent City- Area ta Blue Lake. Eureka Fortuna Trinidad- . Benbow Rohnerville Fields Landing- Ferndale Garberville Bucksport Loleta Myers Flat.... Phillipsville Redway Rio Dell Ferndale Rohnerville Weott Willow Creek.. 30 Areata Trinidad Carlotta Eureka Fickle Hill Fort Seward Orick Fields Landing. Korbel Orick Ferndale Eureka Scotia Dillon Beach- Fort Ukiah Albion Dos Rios Willi ts Point Arena _ Talmage Caspar Lavtonville. Ukiah Ukiah-_ Covelo- 25 150 28 Num- ber of do- mestic services 1,154 10 125 125 39 105 28 1,585 255 7,615 930 100 30 175 134 480 233 3 142 70 34 180 359 67 139 120 50 30 79 14 4 30 2 14 20 104 17 71 135 354 1,291 2,375 12 10 914 111 145 126 Name of water agency Mendocino County — Continued Irrigation Districts Potter Valley Irrigation District-. Public Utility Districts Hopland Public Utility District- Modoc County Irrigation Districts Tule Lake Irrigation District United States Bureau of Reclamation Projects Klamath Project Siskiyou County Municipal Waterworks Dorris Etna Montague Tulelake Yreka Commercial Water Companies Ball Water Company Cottonwood Irrigation and Mining Company Dunsmuir Water Corporation Hornbrook Water Company Macdoel Water Works Shastina Water Service Mutual Water Companies Champion Park Water Agency Farmers Ditch Company Forks of Salmon Water Supply Hilt Water System Klamath River Cooperative Ditch ... Shasta River Water Association Tennant Water Supply Van Fossen and Mason Water System Irrigation Districts Big Springs Irrigation District Butte Valley Irrigation District Grenada Irrigation District Montague Water Conservation Dis- trict Scott Valley Irrigation District Tule Lake Irrigation District United States Bureau of Reclamation Projects Klamath Project Sonoma County Municipal Waterworks Cloverdale Healdsburg Santa Rosa Sebastopol Commercial Water Companies Armstrong Valley Water Company.. Bressie, V. L Camp Meeker Water System Camp Rose Company Cazadero Water Company Citizens Utilities Company of Cali fornia Del Rio Water Company Geyserville Water Works Location, in or near Tulelake. Tulelake. Dorris Etna Montague - Tulelake. - Yreka Weed. Hornbrook. Fort Jones - Hornbrook - Macdoel Shastina Dunsmuir Etna Etna Hilt Klamath River- Montague Weed Dunsmuir Grenada Mt. Hebron. Grenada Montague- Fort Jones - Tulelake... Tulelake- Cloverdale-. Healdsburg. Santa Rosa. SebastopoL. Area Num- irri- ber of gated, do- in mestic acres services Potter Valley 3 , 900 Hopland 30,000 (See Sis Coun 75 5,000 50 325 3,895 Guerneville Bodega Bay Camp Meeker Camp Rose Cazadero El Bonito Monte Rio Guerneville Rio Nido Guernewood ParkJ Del Rio__ Geyserville 2,100 3,647 1,394 3,450 3,650 (See Mo Coun 79,352 kiyou ty) 277 225 179 490 1,136 56 200 198 56 9 375 24 2 150 4 128 46 doc ty) 600 1,424 8,894 1,238 73 52 302 93 121 2,279 152 136 APPENDIX B WATER SERVICE AGENCIES, NORTH COASTAL AREA— Continued 263 Name of water agency Sonoma County — Continued Commercial Water Companies — continued Hacienda Water Company Horgan Water Company, C. J Jenner Water Works Mountain Avenue Water Company... Occidental Water Works Rio Dell Water Company Russian River Terrace Water Com- pany Summer Home Park Water Company Vacation Beach Water Company Windsor Utility Corporation Mutual Water Companies Branger Mutual Water Company Broadmoor Acres Water Supply Carmet by the Sea Water Company. _ East Austin Mutual Water Company. Fircrest Mutual Water Company Forest Home Park Water Supply Graton Waterworks Company Holland Heights Mutual Water Com- pany Kelly Mutual Water Company Lancaster Water Supply McChristian Water Supply Location, in or near Hilton Hilton Jenner Fetters Springs Occidental Rio Dell Russian River Terrace Sebastopol Guerneville Windsor Santa Rosa.. Santa Rosa.. Bodega Bay. Cazadero Sebastopol- .. Forest ville--. Graton Santa Rosa.. Sebastopol- _. Santa Rosa.. Bodega Bay. Area irri- Num- ber of do- mestic services 126 7 66 191 56 131 310 138 128 54 7 19 14 40 38 135 32 100 40 8 35 Name of water agency Sonoma County — Continued Mutual Water Companies — continued Mission Higldands Mutual Water Company Morton Water Service Preston Heights Water Company Russian River Mutual Water Com- pany Salmon Creek Water Company West Beach Mutual Water Company. Willis Mutual Water Company Public Utility Districts Bodega Bay Public Utility District- Camp Rose Public Utility District _ Cotati Public Utility District Special Water Service Districts Sonoma County Flood Control and Water Conservation District Trinity County Commercial Water Companies Weaver ville Water Works County Waterworks Districts Hayfork Water Works District No. 1. Location, in or near Sonoma Glen Ellen. Cloverdale Healdsburg.. Bodega Bay. West Beach . Santa Rosa.. Bodega Bay_ Healdsburg.. Cotati Weaverville. Hayfork. Area irri- gated, in acres (Sells at sale; Num- ber of do- mestic services 10 11 1 10 54 11 5 110 whole- 358 300 2G4 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA WATER SERVICE AGENCIES, SAN FRANCISCO BAY AREA Name of water agency Alameda County Municipal Waterworks Hay ward Pleasant on Commercial Watei Companies California Water Service Companj Citizens Utilities Company of Cali- fornia Gallegos Waterworks- - Mutual Water Companies Baumberg Well Water System--. Cerros Estrellados Water Company - Highland Mutual Water Company Mohrland Mutual Water Association, Inc Norris Canyon Mutual Water Com- pany Counts Water Districts Alameda County Water District. Pleasanton Township County Water District Municipal Utility Districts East Hay Municipal Utility District- Contra Costa County Municipal Waterworks Martinez Pittsburg Walnut Creek Commercial Water Companies Bay Water Company California Water Service Company. Clyde Company Hercules Wat<- Company Sobrante Water Company Webb Waterworks Mutual Water Companies Concord Boulevard Irrigation Group - Diablo Estates Water Corporation .-. El Monte Water Association, Inc Fifty-six Water Group Oak Hill Irrigation Association County Water Districts Anderson Grove County Water Dis- trict Contra Costa County Water District. Lafayette County Water District* Orinda County Water District* Pleasant Hill County Water District*. San Miguel County Water District Saranap County Water District* Public Utility Districts Diablo Public Utility District Municipal Utility Districts East Bay Municipal Utility District. . United States Bureau <>f Reclamation Projects Central Valley Project Location, in or near Hay ward-- Pleasanton Livermore I Decoto [Niles Mission San .lose . Hayward- Oakland.- Hayward. Hayward- Hayward- \\ ashington Town- ship Pleasanton . Oakland - Martinez Pittsburg Walnut Creek. Pittsburg-.. Bay Point Concord Crockett Danville Martinez Oleum Port Costa Valona Clyde Pinole Richmond.. Pittsburg . . Concord _. Concord-. Concord - - Concord- . Martinez - Pacheco Pittsburg Lafayette Orinda Lafayette Walnut Creek- Lafayette I (anville. Oakland- Area Num- irri- ber of gated. do- in mestic acres services 40 500 10 130 7 18 5,501 240 400 (See Ala Coun (Sells at sale I 7,671 754 1,889 1,401 10 242 SO 2,500 77 187,000 3,310 3,500 939 1,555 15,658 115 645 91 98 60 2,743 2,134 1,063 40 1,340 meda ty) whole- Name of water agency Marin County Commercial Water Companies Inverness Park Water Company Inverness Water Works Muir Beach Company Olerna Water System Point Reyes Water Company Seahaven Water System Stinson Peach Water Company Mutual Water Companies Hamilton Air Force Base County Water Districts North Marin County Water District . Public Utility Districts Bolinas Public Utility District Bolinas Beach Public Utility District Municipal Water Districts Marin Municipal Water District Napa County Municipal Waterworks Calistoga Napa St. Helena Commercial Water Companies Hacienda Water Company. _ Luccliesi, F., Water System Mutual Water Companies Bar 49 Ranch Water Supply Bentley Home Sites Water Company Pacific Union College Association Tucker Acres Water Company County Water Districts Congress Valley Napa County Water District Yountville Napa County Water Dis- trict Special Water Service Districts Napa County Flood Control Water Conservation District. _ and San Francisco County Municipal Waterworks San Francisco San Mateo County Municipal Waterworks Burlingame Daly City. . Hillsborough Millbrae Redwood City San Bruno Commercial Water Companies Butano Land and Development Com- pany California Water Service Company . Citizens Utilities Company of Cali- fornia Location, in or near Inverness Park Inverness Muir Beach Olema Point Reyes Station Inverness Stinson Beach Ignacio Nova to - Bolinas Bolinas Beach. Fairfax Mill Valley San Anselmo San Rafael Sausalito, etc. I 'alistoga Napa St. Helena. Napa- Napa St. Helena. Calistoga-. Angwin Calistoga Napa Vouiitville. San Francisco. Burlingame Daly City Hillsborough Millbrae Redwood City. San Bruno Butano Falls Tract Atherton Broadmoor Menlo Park San Carlos San Mateo South San Francisco Woodside Montara Moss Beach Area Num- irri- ber of gated, do- in mestic acres services 350 10 90 (Sells su water o distric 15 66 276 22 31 130 7 237 1,712 175 120 23.K72 580 5,435 923 350 47 10 7 100 7 19 120 rplus utside t) 146.326 5,540 1,186 1 ,320 9,614 3,980 49 30.288 282 APPENDIX B WATER SERVICE AGENCIES, SAN FRANCISCO BAY AREA-Continued 265 Name of water agency San Mateo County — Continued ( lommercial Water < tompanic? — Continued Friendly Acres Water Company.. San Carlos Manor Water System Trout mere Utilities Visitacion City Water Companj Mutual Water Companies Bay View Mutual Water Company. . Brookside Water Company Butano Canyon Mutual Water Com- pany Cuesta La Honda Guild East Almond Cooperative Water Company Kings Mountain Park Water Com- pany Ladera Water Company La Honda Vista Water Company No. 1 Loma Mar Mutual Water and Im- provement Company Los Trancos Water Company Martins Beach Water Supply Marwel Water Company Millbrae Hills Mutual Water Com- pany O'Connor Tract Cooperative Water Company Olds Water Company Palo Alto Park Mutual Water Com- pany Rancho Canada Mutual Water < lom- pany Searview Water Company, Inc Sky L'Onda Mutual Water Company, Inc Ware Acres Mutual Water Company . Woodside Mutual Water Company-.. County Water Districts Belmont County Water District Brisbane County Water District Coastside County Water District North Coast County Water District County Waterworks Districts San Mateo County Waterworks Dis- trict No. 1 (Ravenswood) San Mateo County Waterworks Dis- trict No. 2 (East Palo Alto).-. San Mateo County Waterworks Dis- trict No. 3 (Palomar Park) Municipal Improvement Districts and County Maintenance Districts Willow Road Water Maintenance District Public Utility Districts Diamond Public Utility Districl Millbrae Public Utility Districl Santa Clara County Municipal Waterworks Palo Alto Mountain View Santa Clara Sunnyvale Commercial Water Companies Agnew Water Works Aldercroft Heights Company, Inc.. Almaden Water Company Blacks Almaden Water System California Water Service Company. Campbell Water Company Criswell Water System Peninsula Service Corporation Puccetti Water System Putnam, Tarrant, Estate of Ryan, Water System, H Location, in or near Redwoml < ii\ San Carlos La Honda Brisbane Palo Alt. Redwood ( lity Pescadero Redwood City Palo Alto W.l lil-lil;' Menlo Park... Redw I ' !itj irri- gated. 20 Loma Mar Menlo Park- Half Mooti Bay Woodside Millbrae. Palo Alto... Redwood ( lity Palo Alto. Redwood ( 'rty Redwood City. Redwood < 'itv Woodside Woodside Belmont Brisbane El Granada Half Moon Bay Sharp Park Palo Alto. Palo Alto Palo Alto. Palo Alto. San Francisco Millbrae Palo Alto- Mountain View . Santa Clara Sunnyvale Agnew Los Gatos Los Gatos Almaden Los Altos Campbell Los Gatos Mountain View. Mountain View. _ Cupertino Alma Num- ber of do- mestic services .: i 70 400 140 2 579 Name oi wa tei agency 1,015 120 24 427 5 37 49 275 10 22 50 7 12 91 50 4 200 4 410 24 3 124 13 30 1,774 650 675 1,800 528 913 60 3,700 625 267 11,575 2,832 3,157 3,250 92 110 100 11,026 1,611 10 31 5 11 Santa Clara County — Continued Commercial Water ( lompanies — Continued San Jose Water Works Locatio in or Santa Teresa Water Service. . Water Works of Monte Vista, Ltd.. Mutual Water Companies Berryessa Water Company Blanco Rancho Water Company Briscoe-Emery Water Company ( ihemeketa Park Mutual Water Com- pany Hamilton Water Company Holv City Brotherhood Kirk Ditch.. Laco Mutual Water Company Lake Canyon Mutual Water Com- pany Lyndale Knolls Mutual Water Com- pany Melody Woods Water Company Oak Hill Mutual Water Company Oaknoll Water System Rancho Water Trust Redwood Mutual Water Company, Inc Robleda Water Association Rolling Hills Mutual Water Companj Saratoga Heights Mutual Water Com- pany Spinsk Water System University Park Improvement Asso- ciation fSan .In e I Campbell 1 Los ( ratos Saratoga Sim .1" Sunnyvale Sim Jose I, us Utos San Jose . Area irri- in 130 County Water Districts Milpitas County Water District Special Water Service Districts Santa Clara County Flood Control and Water Conservation District Solano County Municipal Waterworks Fairfield Suisun Valle.jo Los Cat os Sunnj \ id' Holy City. Campbell-. Los Altos Los Gatos _ Los Altos Holy City Palo Alto Mountain View. San Jose Redwood Estates. Los Altos Cupertino 138 20 1,210 Num- ber of do- mestic sen ices 49,791 30 718 7 42 27 151 12 Saratoga. Los Altos. Mountain View Milpitas. Commercial Water Companies California-Pacific Utilities Company . Irrigation Districts Solano Irrigation District Reclamation Districts Reclamation District 1607. Special Water Service Districts Solano County Flood Control and Water Conservation District United States Bureau of Reclamation Projects Solano Project Sonoma County City Waterworks Municipally Owned Sonoma. Privately Owned Water Companies California Water Service Compnaj Donaghy, Water Company Glen Ellen Waterworks Penngrove Water Company ....- Sonoma Water and Irrigation Com- pany Special Water Service Districts Sonoma County Flood Control and Water Conservation District Fairfield. Suisun. - Vallejo.. Benieia. Fairfield ( lollinsville Sonoma. 100 (Sells su water ii districl 15 00 9 19 12 10 20 290 28 2 900 (See Ta 2,461 (Sells at sale) (Sells at sale) rplus utside ) 1,031 775 i: ;i 1 ,600 l,l«. :,) /Sonoma Vista \Boyes Springs whole- whole- 840 ' Operated as part of the East Bay Municipal Utility District. 266 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA WATER SERVICE AGENCIES, CENTRAL COASTAL AREA Name of water agency Monterey County Municipal \\ aterworks Gonzales Greenfield Soledad Commercial Watei Companies Ale. j Water Service Alisal Heights Water Company. Ambler Park Water Utility Arroyo Seco Water Company.. Baird Water Company Bolsa Knolls Water Company _ _ California Water and Telephone < "< . 1 1 1- pany . Chualar Water Works East Monterey Water Service Fruitland Water Company Los Lomas Water Company Pacific Gas and Electric Company... Rancho Del Monte Water Company. Mutual Water Companies Acacia Park Water and Improvement Association Aneste Water Supply ( 'assenelli Water Supply Castroville Subdivision Water Supply Chetmore Acres Water Association __ Clark Colony Water Company Coastlands Mutual Water Company. Del Monte Ice Company Del Monte W r ater Company Fort Romie Water Company Gabilan Water Company Laguna Seca Water Company, Inc Larson Water Supply McKanna Water Supply Mountain Springs Water Company... Orchard Lane Water Association Partington Mutual Water Company. . Phillips Water Supply Pierri Water Supply Reliz Water Company Rizzo Mutual Water Company.. Roberti Water Supply Rolling Hills Ranchos Water Associa- tion Snyder and Biddle Water Supply Spreckels Sugar Company Springfield Mutual Water Company Tierra Verde Mutual Water Company Union Water Company of Greenfield Virginia Acres Water Company, Inc. West Side Water Company of Green- field White Tract Water Company Wildwood Water Company San Benito County Municipal Waterworks Hollister San Juan Bautista ' Commercial Water Companies Tres Pinos Water System Mutual Water Companies Hepsedam Mutual Water Company. San Justo Mutual Water Company.. Irrigation Districts Hollister Irrigation District Location, in or near Gonzales. . < [reenfield Soledad Alisal Salinas Ambler Park Soledad Salinas Salinas ( larmel Carmel Highland Monterey Pacific Grc\ e Chualar Monterey Watsonville Watsonville King City Salinas / Carmel .... Area Num- irri- ber of gated, do- in mestic acres services 60 Salinas Salinas Soledad Castroville.. Watsonville. Greenfield.. Carmel Castroville Salinas Soledad Salinas Salinas San Lucas Bradley 60 5 110 120 Salinas Monterey. . Castroville . Castroville. Greenfield. Castroville. Castroville. Salinas Castroville. Spreckels. _ Castroville. Salinas Greenfield. Salinas 50 3,600 220 3,020 Greenfield _ Salinas Salinas Hollister San Juan Bautista Tres Pinos . Hollister. Hollister. 30 530 12 427 Hollister I 17,500 357 375 482 2,134 256 70 53 290 114 15,615 66 1,675 16 145 762 49 165 10 5 15 60 10 200 3 17 1,900 322 40 Name of water agency San Luis Obispo County Municipal Waterworks Arroyo Grande Paso Robles Pismo Beach San Luis Obispo Commercial Water Companies Avila Water Company Oceano Water Company Mutual Water Companies Atascadero Mutual Water Company Branch's Mill Water Company Cambria Pines Service Corporation. _. Garden Farms Mutual Water Com- pany Green River Mutual Water Company Grieb-Taylor Ditch Company McNeill Pump Company Morro Rock Mutual Water Company Paso Robles Beach Water Association County Water Districts Grover City County Water District _. County Waterworks Districts San Luis Obispo County Waterworks District No. 1 (San Miguel) San Luis Obispo County Waterworks District No. 2 (Morro Bay) San Luis Obispo County Waterworks District No. 4 (Morro Bay) San Luis Obispo County Waterworks District No. 5 (Templeton) San Luis Obispo County Waterworks District No. 6 (Santa Margarita) ... San Luis Obispo County Waterworks District No. 9 (Bay wood) Santa Barbara County Municipal Waterworks Lompoc Santa Barbara Santa Maria Commercial Water Companies Campodonico Water Works Carpinteria Water Company, Inc Casitas Road Water Company Evergreen Service Company Mayer Tract Waterworks Ocean Oaks Water Company Orcutt Town Water Company Sol vang Water Works Toro Canyon Company, Inc Mutual Water Companies Anderson Water Supply Betteravia Water Supply Carneros Water Company Cathedral Oaks Mutual Water Com- pany Dow Tract No. 1 Dow Subdivision Water Company Erickson Subdivision Association Gobernador Land and Water Com- pany Hyland Mutual Water Company. __ Ivydene Mutual Water Company. _ La Cumbre Mutual Water Company Las Positas Mutual Water Company Mesa Associates Mutual Water Com- pany Miramar Addition Improvement Com- pany J Location, in or near Area Num- irri- ber of gated, do- in mestic acres services Arroyo Grande.. Paso Robles Pismo Beach San Luis Obispo. Avila _ _ ( Iceano Atascadero Arroyo Grande. Cambria Atascadero Paso Robles Arroyo Grande Arroyo Grande. Cayucos Cayucos Grover. San Miguel Morro Bay Morro Bay Templeton. _. Santa Margarita Morro Bay 200 110 38 Lompoc Santa Barbara Santa Maria Guadalupe... Carpinteria-. Carpinteria __ Santa Maria. Santa Maria. Carpinteria Orcutt Solvang Suniinerland. 10 225 Santa Ynez. Betteravia . Goleta Santa Barbara Goleta Goleta Santa Barbara Carpinteria Santa Barbara Montecito Santa Barbara Santa Barbara 7,000 564 500 1.004 1,671 945 5,000 150 1,280 410 54 17 138 280 750 175 1.075 480 189 157 145 1,406 13,270 3,924 574 1,060 4 143 10 348 306 168 16 66 16 3 56 40 15 75 18 369 44 APPENDIX B 267 WATER SERVICE AGENCIES, CENTRAL COASTAL AREA-Continued Name of water agency Santa Barbara County — Continued Mutual Water Companies — continued Montecito Creek Water Company. .. More Mesa Mutual Water Company Newlove Water Company. . Painted Cave Mutual Water Com- pany _--- Paradise Improvement Association. . Patterson Road Mutual Water Corn- Location, in or near Santa Barbara . Santa Barbara. Santa Maria... pany Ranchoil Mutual Water Company .. Rancho Sueno Mutual Water Com- pany Rincon Del Mar Mutual Water Corn- Santa Barbara. Santa Barbara . Orcutt.. Cuyama. Santa Barbara. pany Rosario Park Water District ... Riven Rock Mutual Water Company. Santa Maria Air Base Water Supply. . Serena Mutual Water Company San Marcos Trout Club Shepard Mesa Mutual Water Com- pany Sunset Road Mutual Water Company. Sykes Water Supply Terrace Mutual Water Company... Todmorden Mutual Water Company County Water Districts Carpinteria County Water District. . Goleta County Water District Montecito County Water District. . Suuimerland County Water District. County Waterworks Districts Santa Barbara County Waterworks District No. 1 Carpinteria Santa Barbara . Santa Barbara . Santa Maria — Santa Barbara . Santa Barbara . Carpinteria Santa Barbara . Santa Barbara . Santa Barbara . Goleta Municipal Improvement Districts and County Maintenance Districts Solvang Municipal Improvement District Special Water Service Districts Santa Barbara County Water Agency United States Bureau of Reclamation Projects Cachuma Project Santa Clara County Municipal Waterworks Gilroy Morgan Hill Commercial Water Companies Mecchi Water Company San Martin Water Works. . Buellton. Solvang. Gilroy Morgan Hill. Morgan Hill. San Martin.. Mutual Water Companies Carpignano, James. .. Cox, Agnes, Water Supply - Special Water Service Districts Santa Clara County Flood Control and Water Conservation District- Santa Cruz County Municipal Waterworks Santa Cruz Watsonville Commercial Water Companies Beltz Water System Ben Lomond Redwood Park Water Company Big Basin Water Company San Martin. Los Gatos.- Santa Cruz. Watsonville. Twin Lakes. Ben Lomond. . Boulder Creek . ( larpinteria Goleta Santa Barbara — Summerland Area irri- gated, in acres 109 00 Num- ber of do- mestic services 155 3 23 4,700 16,000 2,325 (Sells at sale) (Sells at sale) 16 93 19 18 6 110 17 33 15 31 50 50 11 Name of water agency 1 ,000 1,422 145 105 371 whole- whole- tSee San ( 'iiunt 1,442 705 45 ta Cruz y) Santa Cruz County — Continued Commercial Water Companies — continued Citizens Utilities Company of Cali forma Felton Water Company Forest Glen Water Company .. La Selva Beach Water Company.-. Location, in or near Monterey Baj Water Company. Riverside Grove Water Company, Inc. Zay ante Water Company (Sells su rplus wate r outside distric 1 ,200 11,100 5,861 757 115 45 Mutual Water Companies Assemblies of God Bauer Water Company Beulah Park Mutual Water Company Big Redwood Park Mutual Water Company Bracken Brae Corporation... California Conference of the Free Methodist Church Camp Evers Store Water Supply— Cathedral Woods Mutual Water Company Cox, Agnes, Water Supply- - Davenport Water Supply. - Duffield Acres Water Supply- - Forest Lakes Mutual Water Com- Ben Lomond Boulder Creek Brookdale Felton Aptos La Selva Beach . . Aptos Capitola Rio del Mar Seacliff Soquel Riverside Grove. Zayante Santa Cruz. 1 elton Santa Cruz. Felton Boulder Creek. pany — Forest Springs Mutual Water Com- pany Gold Gulch Mutual Water Company Highland Park Water Service... Larita Woods Mutual Water Com- pany, Inc Laurel Community League, Inc... Lompico Cooperative Water Associa- tion Love Creek Heights Mutual Water Association Manana Woods Mutual Water Com- Santa Cruz. Soquel Los Gatos-- Davenport.- Watsonville Felton Boulder Creek . Watsonville . Felton. Laurel . Felton Ben Lomond- pany Mountain Springs Water Service. _. Mount Hermon Association. . New Freedom Mutual Water System. Olympia Mutual Water Company... Paradise Park Masonic Club Ramona Woods Mutual Water Com- pany San Lorenzo River Park Mutual Water Company San Lorenzo Woods Mutual Water Company Santa Hacienda Mutual Water Com- pany Sunset Beach Mutual Water Com- pany Terrace View Water Company Vine Hill Mutual Water and Im- provement Company Santa Cruz Ben Lomond Mount Hermon . Watsonville Olympia Santa Cruz Boulder Creek. Boulder Creek- Boulder Creek . Santa Cruz — County Water Districts ( 'mitral Santa Cruz County Water District San Lorenzo Valley County Water District County Waterworks Districts Santa Cruz County Waterworks District No. 1 Special Water Service Districts Santa Cruz County Flood Control and Water Conservation District Watsonville . Santa Cruz. Santa Cruz. Area irri- gated, in acres Aptos Boulder Creek, etc. Num- ber of do- mestic services 35 640 20 Davenport. 2,138 711 35 193 3,076 98 167 15 30 14 24 25 12 7 11 80 27 132 108 27 12 30 27 238 20 11 432 95 30 375 23 79 47 30 30 5 24 (Sells at -ali'l 75 whole- 268 WATER UTILIZATION AND REQUIREMENTS OF CALIFORNIA WATER SERVICE AGENCIES, SOUTH COASTAL AREA Name of water agency Los Angeles County Municipal Waterworks AJharabra Arcadia Avalon Azusa Beverly Hills B ii rbank Con ip ton Covina El Monte El Segundo Glendale Glendora Hawthorne Huntington Park Ingle wood La Verne Long Beach Los Angeles Ly nwood Manhattan Beach Monrovia Monterey Park Pasadena Pomona San Fernando Santa Monica Sierra Madre Signal Hill South Gate South Pasadena Torrance Vernon Whittier Commercial Water Companies Azusa Valley Water Company. Berlu Water Company Bouquet Canyon Water Company California Michigan Land and Water Company California Water Service Company,. California Water and Telephone Company Central Gardens Water Company... Coast Water Company Conservative Water Company. Dominguez Water Corporation. Duarte Domestic Water Company. _ East Gardena Water Company East Pasadena Water Company, Ltd. Fairacres Water Company Ideal Petroleum Company Investment Water Corporation, Ltd. Junior Water Company, Inc Lakewood Waterand Power Company. La Mirada Water Company Malibu Watei ( Jompany Montebello Land and Water Company Narbonne Ranch Water Company No. 2 Newhall Water Company Orchard Dale Service Company Location, in or near Area irri- gated. in acres Alhambra Arcadia Avalon Azusa Beverly Hills Burbank Compton Covina El Monte Kl Segundo. Glendale < rlendora Hawthorne Huntington Park. Inglewood La Verne Long Beach Los Angeles Lynwood Manhattan Beach Monrovia Monterey Park... Pasadena Pomona San Fernando Santa Monica Sierra Madre Signal Hill South Gate South Pasadena Torrance Vernon Whittier /Covina I, West Covina Bellflower Saugus Lamanda Park East Pasadena East Los Angeles Eastmont Hermosa Beacli Redondo Beach Torrance Azusa El Monte Rosemead San Gabriel San Marino South Gate \Lynwood Bell Gardens Watts fRedondo Beach { Wilmington Duarte Gardena Lamanda Park East Pasadena North Long Beach Bellflower Los Angeles Norwalk Lakewood La Mirada Rancho Topanga Malibu Montebello 400 56 23 Lomita Newhall Luitweiller Orchard Dale 2,000 800 56 60 1.200 360 650 Num- ber of do- mestic services 15,042 8,964 1,000 3,23any. _ Big Rock Beach Water Company.. Blue Ribbon Community Water Company Bonita Water Company fSan Dimas ^Charter Oak Baldwin Park El Monte Whittier Area Num- irri- ber of gated, do- in mestic acres services 1,646 2,037 24,326 500 22 198 1,480 27,453 [Culver City I Lennox [and 25 others Topanga Can von . 1.070 69,491 545 Nor walk . 941 fCovina Downey Glendora J Los Nietos Puente South Covina West Covina Whittier Santa Fe Springs . 1,550 7,587 1.1.30 1.280 493 Compton El Monte Puente Rosemead. 77 97 La Canada .. El Monte 50 4 60 Garvey . . 171 324 1,000 20 380 La Crescenta . ("La Crescenta Montrose \ [Verdugo Downey 126 6,000 Artesia 22 Artesia 30 Long Beach ... 320 Claremont Azusa .. 200 1,200 4,000 7 Azusa El Monte 20 El Monte 18 Baldwin Park Whittier 135 La Verne 402 1.001 87 Claremont.. Puente Artesia .. _ 35 Bellflower Bellflower _ Redondo Beach Mint Canyon Puente. 120 195 3 300 50 250 1,606 112 43 1 Whittier.. 75 Whittier. _ 200 Bell flower . 178 Malibu 10 101 El Monte 105 Claremont 160 1 APPENDIX B WATER SERVICE AGENCIES, SOUTH COASTAL AREA-Continued 269 Name of water agency Location, in or near Area Num- irri- ber of gated, do- in mestic acres services Name of water agency Location, in or near Area irri- gated, in acres Num- ber of do- in. ■-tic services Los Angeles County — Continued Mutual Water Companies — Continued Bonnie Brae Water Company Botello Water Company Boulder Water Company Boulevard Water Company No. 2 Briggs Terrace Mutual Water Company California Domestic Water Company Canon Water Company of Pomona _ Cantrill Mutual Water Company Canyon View Water Company Cassel Water Company Castaic Mutual Water Company Cate Ditch Company C and C Mutual Water Company... Cedar Avenue Mutual Water < 'omps ny, Inc Center City Water Company Century Center Mutual Water As sociation Century City Mutual Water ( 'mnpau\ Cerritos Park Mutual Water Company Cerro del Oro Water Company Chatsworth Lake Mutual Water Corporation Cherryvale Water Users Association. Chrisco Mutual Water Association.. Christian Acres Mutual Water Com- pany Cienega Springs Water Company Citrus Grove Heights Water Com- pany City Farms Mutual Water Company. Claremont Basin Mutual Water Com- pany Claremont Cooperative Water Com- pany Claremont Heights Irrigation Com- pany Colima Tract Water Company College Way Mutual Domestic Com- pany Columbia Land and Water Company. Community Water Supply Comstock Water Company Connemara Mutual Water Company Contract Water Company of Azusa _ Cook Tract Water Company Corona Del Malibu Corral Canyon Mutual Water Com- pany Covina Highlands Water Company _ . Covina Irrigating Company Crescenta Mutual Water Company Cross Water Company Crystal Mutual Water Company Deerpath Mutual Water Company Del Monte Irrigation Company Del Rio Mutual Water Company Didier Farms Mutual Water Company Downey Valley Water Company Dreher, E. L., Agent Duarte Mutual Water Company Durward Well Company East End Irrigation Company East Gardena Water Company Edgemont Water Company El Camino Water Company El Campo Mutual Water Company _. El Monte Community Association El Segundo Land and Improvement Company Eureka Water Company Fairview Mutual Water Company Farm Mutual Water Company Fickewirth Mutual Water Company, Ltd Flintridge Heights Mutual Water Company Francisquito Water Company ( 'laremonl San Dimas Claremont Baldwin Park. La Crescenta Whittier Pomona El Monte Baldwin Park. < 'm ilia Castaic Pico Baldwin Park. F.l Monte. . Paramount . ( 'learwater. Hollydale.. Bellflower. . La Verne Chatsworth Long Beach Mint ( 'imyiiii Hawaiian Gardens Glendora Whittier. Artesia . * In remont- i Lip'mont. ( llaremont Whittier La Verne San Dimas . Norwalk Puente . Azusa Azusa Paramount _ Mahbu Malibu Covina ( lovina Me nt rose Puente Whittier Santa Monica- Pomona El Monte Puente Downey Claremont Duarte La Verne Pomona Gardena La Verne Claremont San Marino El Monte El Segundo. Claremont __ Claremont. _ El Monte... Puente Glendale. Puente 190 110 300 50 4,700 3,100 250 180 200 300 140 80 330 21 1,000 600 300 500 510 150 55 1,200 60 3,500 1,000 1,800 155 25 170 74 175 250 40 300 15 70 188 30 330 :>s 75 65 125 300 78 125 100 28 48 127 3 150 46 2,960 450 318 84 169 20 53 54 130 Los Angeles County — Continued Mutual Water Companies — Continued Franklin Avenue Water Company, Inc Fruit Street Water Company Gardena Water Supply Company Giano Mutual Water Company Glendora Independent Water Com- pany Glendora Irrigating Company Golden Poppy Park Water Tiu-t Grazide Rancho Mutual Water Com- pany Harrison Avenue Water ('