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THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA DAVIS STATE OF CALIFORNIA DEPARTMENT OF PUBLIC WORKS PUBLICATIONS OF THE DIVISION OF WATER RESOURCES EDWARD HYATT, State Engineer Reports on State Water Plan Prepared Pursuant to Chapter 832, Statutes of 1929 BULLETIN No. 27 VARIATION AND CONTROL OF SALINITY IN SACRAMENTO-SAN JOAQUIN DELTA AND UPPER SAN FRANCISCO BAY 1931 LIBRARY UNIVERSITY OF CALIFORNIA 80995 X DAVIS TABLE OF CONTENTS Page ACKNOWLEDGMENT 8 ORGANIZATION 9 ENGINEERING ADVISORY COMMITTEE 10 FEDERAL AGENCIES COOPERATING IN INVESTIGATION H STATE AGENCIES COOPERATING IN INVESTIGATION 12 CHAPTER 832, STATUTES OF 1929 13 FOREWORD 14 Chapter I INTRODUCTION, SUMMARY AND CONCLUSIONS 15 Area of salinity investigations 16 Sacramento-San Joaquin Delta 17 Suisun Bay area 18 Carquinez Strait area 19 San Pablo Bay area 19 Developments and interests affected by saline invasion 20 Previous investigations 22 The Antioch suit 23 Investigations during period 1921 to 1929 23 Scope of 1929 investigation 24 Salinity conditions 28 Basic factors governing salinity conditions 30 Stream flow 30 Consumptive use of water in delta 32 Tidal action _-__— 32 Relation of stream flow into delta to salinity 35 Relation of tidal action to salinity 38 Tidal diffusion 38 Control of salinity 40 Control flow 40 Required supplemental water supply for control 41 Conclusions 42 Chapter II SALINITY CONDITIONS IN SACRAMENTO-SAN JOAQUIN DELTA AND UPPER SAN FRANCISCO BAY 46 Historical records of salinity conditions 46 Records of salinity observations 50 Extent of saline invasion 54 Salinity of drainage water from delta islands 56 Effect of salinity conditions on developments and interests 59 Basic factors governing salinity conditions 63 Stream flow 64 Variation of stream flow 65 Consumptive use of water in delta 68 Tides 75 Chapter III RELATION OF STREAM FLOW INTO DELTA TO SALINITY 87 Relation of total seasonal stream flow into delta to salinity 87 Maximum salinity during season 87 Minimum salinity during season 91 Advance of salinity 95 Relation of summer stream flow into delta to salinity 97 Relation of rate of stream flow into delta to salinity 102 Relation of source and distribution of stream flow into delta to salinity 108 Distribution of flow of Sacramento River in delta channels 109 Effect of distribution of Sacramento River flow on salinity 120 80995 TABLE OF CONTENTS — Continued Page Effect of irrigation, storage and reclamation developrpents on stream flow into delta 124 Growth of irrigation 124 Growth of reservoir storage developments 136 Effect of ui)stream reclamation development on stream flow into delta 140 Estimated reduction in stream flow into delta 147 Chapter IV RELATION OP TIDAL ACTION TO SALINITY 151 San Francisco Bay tidal basin 151 Historical limits 152 Effect of hydraulic mining and silting 153 Growth and effect of reclamation in delta 157 Effect of recent changes in delta tidal basin 161 Tidal action 163 The tidal prism 164 Advance of tides 165 Tidal volumes in delta and Suisun Bay 170 Tidal prism volumes in delta and Suisun Bay 172 Tidal flow 174 Effect of tidal action on salinity 179 Tidal variations of salinity 182 Variation of salinity with tidal stage 195 Lateral and depth variations of salinity 198 Variation of salinity with tidal velocity 202 Variation of salinity with tidal flow 206 Tidal diffusion 208 • Magnitude of tidal diffusion 210 Variation of tidal diffusion with salinity 212 Geographical variation of tidal diffusion 212 Relation of tidal diffusion to tidal flow 212 Effect of recent changes in delta tidal basin on saline invasion — 214 Effect of Sacramento River channel enlargement 216 Effect of flooding of previously reclaimed lands 217 Effect on tidal diffusion 218 Effect of Stockton ship canal 218 Chapter V CONTROL OP SALINITY 219 Stream flow required for control of salinity 220 Net control flows 22l Desired point and degree of control of salinity 221 Proposed net control flow 224 Gross stream flow into delta for control of salinity 226 Supplemental water supply for control of salinity 232 Works required for proposed control of salinity by stream flow 235 Results of proposed control of salinity 237 APPENDIX A FIELD METHODS AND I'ROCEDURE IN SALINITY INVESTIGATION 245 APPENDIX B LABORATORY METHODS FOR DETERMINATION OF SALINITY 261 APPENDIX C RECORDS OP SALINITY OBSERVATIONS 267 APPENDIX D STREAM FLOW INTO SACRAMENTO-SAN JOAQUIN DELTA 293 GLOSSARY DEFINITION OP TECHNICAL TERMS 433 PUBLICATIONS OP THE DIVISION OF WATER RESOURCES 438 (2) LIST OF TABLES Table Page 1 Consumptive use of water in Sacramento-San Joaquin delta 69 2 Total consumptive use of water in Sacramento-San Joaquin delta, 1929 season 70 3 Area and consumptive use of irrigated crops in Sacramento-San Joaquin delta, 1924 to 1929 73 4 Location and period of record of automatic tide gages 76 5 Tidal data for San Francisco Bay and Sacramento-San Joaquin delta channels 78 6 Relation of seasonal stream flow into delta to maximum salinity during season, 1920-1929 88 7 Relation of seasonal stream flow into delta to minimum salinity during season, 1923-1929 92 8 Relation of seasonal stream flow into delta to date of beginning of advance of salinity, 1920-1929 96 9 Relation of summer stream flow into delta to maximum salinity during season, 1920-1929 100 10 Relation of rate of stream flow into delta at time of maximum salinity to minimum salinity during season, 1920—1929 105 11 Summary of tidal cycle stream flow measurements 116 12 Area irrigated by direct diversion from Sacramento and San Joaquin River systems, exclusive of Sacramento-San Joaquin delta, 1879—1929 126 13 Gross annual irrigation diversions from Sacramento and San Joaquin River systems, exclusive of Sacramento-San Joaquin delta, 1879-1929 128 14 Gross monthly irrigation diversions from Sacramento and San Joaquin River systems, exclusive of Sacramento-San Joaquin Delta, 1912 to 1929 131 15 Reservoir storage capacity on Sacramento and San Joaquin River systems, 1850-1929 137 16 Principal storage reservoirs on Sacramento and San Joaquin River systems. 138 17 Monthly gross diversions to storage on Sacramento and San Joaquin River systems, 1912-1929 141 18 Delayed outflow from Sacramento Valley flood basins in their natural state before reclamation, 1907-1920 147 19 Reduction in stream flow into delta resulting from upstream irrigation and storage developments, 1911-1929 149 20 Area and volume of tidal prism in San Francisco Bay tidal basin 151 21 Annual minimum and maximum river stages of Sacramento River at Sacramento, 1849-1929 157 22 Growth of reclamation in Sacramento-San Joaquin delta, 1860-1930 158 23 Time interval between occurrence of tidal phases at Presidio and at points in San Francisco Bay and Sacramento-San Joaquin delta 166 24 Tidal prism volumes in tidal basin of Suisun Bay and of Sacramento-San Joaquin delta l'^7 25 Summary of tidal cycle salinity surveys, 1929 180 26 Summary of river cross section salinity surveys, 1929 200 (3) LIST OF PLATES— Continued Plate Page XXVI Distribution of flow of Sacramento River through branch channels below Sacramento following 118 XXVII Relation of tidal flow through Three Mile Slough to range and dura- tion of tides at Three Mile Slough 121 XXVIII Relation of tidal flow through Three Mile Slough to range and dura- tion of tides at Presidio 122 XXIX Growth in area irrigated by direct diversion from Sacramento and San Joaquin River systems, exclusive of delta of Sacramento and San Joaquin rivers 127 XXX Growth of irrigation diversions from Sacramento and San Joaquin River systems 129 XXXI Monthly diversions for irrigation and storage from Sacramento and San Joaquin River systems, exclusive of deltas of Sacramento and San Joaquin rivers following 136 XXXII Growth of reservoir storage capacity in Sacramento and San Joaquin River systems — 139 XXXIII Changes in flood channels and basins of Sacramento and San Joa- quin rivers effected by flood control and reclamation development, and location of auriferous gravel areas following 140 XXXIV Tidal basin of Sacramento-San Joaquin delta and upper San Fran- cisco Bay region, showing progressive changes in reclamation developments, time of occurrence of tidal phases and tidal flow stations following 152 XXXV Changes in channel bed of Sacramento River, 1841 to 1^29 --folloicing 156 XXXVI Growth in reclamation development in the Sacramento-San Joaquin delta 159 XXXVII Rate of advance of tides in Sacramento-San Joaquin delta channels 169 XXXVIII Accumulated tidal volumes in Sacramento and San Joaquin delta channels following 170 XXXIX Accumulated tidal volumes in Suisun Bay — 171 XL Tidal prism volumes in Sacramento River channels (Aug. 27-28, 1929) following 172 XLI Tidal prism volumes in Sacramento River channels (Dec. 18-19, 1929) following 172 XLII Tidal prism volumes in San Joaquin River channels (Aug. 27—28, 1929) following 172 XLTII Tidal prism volumes in San Joaquin River channels (Dec. 18-19, 1929) following 172 XLTV Tidal prism volumes in Suisun Bay and delta channels (May 13-14, 1929) follouing 172 XLV Tidal prism volumes in Suisun Bay and delta channels (May 13-14, 1929) following 172 XLVI Relation of tidal prism volumes to tidal range (Antioch and Collins- ville home sections) 175 XLVII Relation of tidal prism volumes to tidal range (Suisun Bay home sections) 176 XLVIII Tidal variation of salinity at Point Orient 183 XLIX Tidal variation of salinity at Crockett (Surveys No. 1 and 6) 184 L Tidal variation of salinity at Crockett (Survey No. 7) 185 LI Tidal variation of salinity at Bulls Head Point 186 LII Tidal variation of salinity at Avon and Nichols 187 LIII Tidal variation of salinity at Bay Point 188 (C) LIST OF PLATES — Continued Plate Page LIV Tidal variation of salinity at Collinsville 189 LV Tidal variation of salinity at Antioch 190 LVI Tidal variation of salinity at Antioch Bridge , 191 LVII Tidal variation of salinity at Rio Vista 192 LVIII Tidal variation of salinity at Central Landing and Curtis Landing__ 193 LIX Tidal variation of salinity at Sacramento I Street Bridge and Moss- dale 194 LX Variation of salinity with tidal stage following 194 LXI Rate of variation of salinity with tidal range, in relation to mean salinity 196 LXII Relation of salinity to tidal stage following 196 LXIII Variation of salinity with depth folloiving 198 LXIV L.ateral variation of salinity __ following 202 LXV Variation of tidal velocity in San Joaquin River near Antioch — following 202 LXVI Variation of tidal velocity in Sacramento River near Collinsville •■ following 202 LXVII Variation of salinity and tidal velocity in Sacramento River near Collinsville 204 LXVIII Variation of salinity and tidal velocity in San Joaquin River near Antioch '. 205 LXIX Variation of salinity and tidal velocity with depth following 206 LXX Variation of salinity with tidal action and stream flow at Antoch, 1929 folloioing 206 LXXI Channel volumes in Suisun Bay, Sacramento and San Joaquin rivers folloioing 210 LXXII Estimated mean surface zone salinity (Bulls Head Point, Bay Point, O and A Ferry and Collinsville) following 210 LXXIII Estimated mean surface zone salinity (Mayberry, Emmaton, Three Mile Slough, Rio Vista, Antioch, Curtis Landing, and Jersey) — following 210 LXXIV Tidal diffusion in the combined channels of the Sacramento and San Joaquin rivers folloioing 212 LXXV Tidal diffusion in Suisun Bay -- folloioing 212 LXXVI Geographical variation of tidal diffusion 213 LXXVII Relation of tidal diffusion to tidal flow 215 LXXVIII Net stream flow for control of salinity at points in Suisun Bay and lower delta 222 LXXIX Gross stream flow into delta for control of salinity 0.6 miles below Antioch, with comparative stream flow and salinity records for years 1920-24-26-27-29 227 LXXX Gross stream flow into delta for conti'ol of salinity at Collinsville, with comparative stream flow and salinity records for years 1920-24-26-27-29 230 LXXXI Gross stream flow into delta for control of salinity at O and A Ferry, with comparative stream flow and salinity records for years 1920-24-26-27-29 231 LXXXII Delta of Sacramento and San Joaquin rivers, showing limits of salinity encroachment of 100 parts of chlorine per 100,000 parts of water, 1920 to 1931, inclusive following 260 ( 7) ACKNOWLEDGMENT In carrjang out the investigation of salinity in the Sacramento-San Joaquin Delta and San Francisco Bay, valuable assistance has been rendered by many individuals and public and private agencies. Many have cooperated in the work of obtaining water samples at salinity observation stations. The owners of lands in the delta have contributed the time of their employees for taking water samples with- out cost to the State. In addition they have cooperated in furnishing basic data as to crop acreages and yields and as to irrigation diversions and drainage pumping operations. Executives and engineers of indus- tries and other agencies have furnished records of salinity. Valuable cooperation has been received from several departments of the Federal Government, including the Water Resources and Topo- graphic branches of the Geological Survey of the Depai'tment of the Interior, the Division of Agricultural Engineering of the Bureau of Public Roads of the Department of Agriculture, and the Coast and Geodetic Survey of the Department of Commerce. The State Division of Highways has cooperated in the testing of salinity samples. Special commendation is due the engineers on the Advisory Com- mittee of this investigation whose advice and assistance have con- tributed materially to the successful prosecution and completion of the studios and report j^resented herein. (S ) ORGANIZATION Walter E. Garrison Director of Public Works Edward Hyatt State Engineer This bulletin was prepared under the direction of A. D. Edmonston Deputy State Engineer By Raymond Matthew Hydraulic Engineer Principal Assistants J. A. Case D. R. Warren Assistants E. L. Clark W. A. Laflin 0. H. CosHow D. G. McBean A. H. Hubbard F. H. Paget Conrad Weil, Jr. Delineators J. T. ]\Iaguire L. R. Creek E. N. Sawtelle J. A. Parent: R. R. Ege The field work in connection -\^dth the investigation and the preparation of Appendix A were under the immediate direction of Harlowe Stafford Hydraulic Engineer M. H. Blote Principal Assistant J. J. Haley, Jr. AdministraJive Assistant (9) ENGINEERING ADVISORY COMMITTEE This investigation Avas outlined and the report prepared with the advice of and in consultation with the following consulting engineers: G. A. Atiierton H. L. IIaehl T. H. Means ( 10 ) FEDERAL AGENCIES COOPERATING IN INVESTIGATION DEPARTMENT OF THE INTERIOR Geological Survey, Water Resources Branch H. D, McGlashan, District Engineer Valuable cooperation was rendered b.y Mr. McGlaslian in furnish- ing advance information on stream flow entering the delta, and in improving the installations of certain stream gaging stations main- tained for this purpose. Geological Survey, Topographic Branch Thomas D. Gerdine,* Division Engineer Through cooperative agreement, precise level lines were run in the San Francisco Bay region and delta under the direction of Mr. Ger- dine for the purpose of referring the automatic tide gages to a common precise level datum. DEPARTMENT OF AGRICULTURE Bureau of Public Roads, Division of Agriculttiral Engineering W. W. McLaughlin, Associate Chief Under cooperative agreement, the Division of Agricultural Engi- neering under the general direction of Mr. McLaughlin and immediate supervision of Major 0. V. P. Stout, made detailed measurements of the consumptive use of water by crops and natural vegetation in the Sacramento-San Joaquin Delta, covering a period of over six years. DEPARTMENT OF COMMERCE Coast and Geodetic Survey Thos. J. Maher, Inspector, San Francisco Field Station Commander Maher of the Coast and Geodetic Survey furnished assistance and advice and loaned tide gage equipment in the work of obtaining tidal records in the San Francisco Bay and delta regions. * Since deceased. (11) STATE AGENCIES COOPERATING IN INVESTIGATION DIVISION OF HIGHWAYS C. H. PuRCELL, State Highivay Engineer The testing laboratory of the Division of Highways under the direction of Thomas E. Stanton, Materials and Research Engineer, has rendered most valuable assistance in the testing of all water samples for salinity since 1923. Chemical Testing Engineer G. H. P. Liclit- hardt has been in general charge of the work assisted by Testing Engineer Aids H. M. Aaron and N. T. Austin and Assistant Testing Engineers W. J. Lentz and E. F. Pennock. The expeditious and efficient manner in which the testing of samples was handled has greatly aided the effective prosecution of the investigation. Appendix B con- tains a brief report prejiared by Thomas E. Stanton on "Laboratory Methods for Determination of Salinity." (12) CHAPTER 832, STATUTES OF 1929 An act making an appropriation for work of exploration, investigation and preliminary plans in furtherance of a coordinated plan for the conservation, development and utilization of the water resources of California including the Santa Ana River, Mojave River and all water resources of southern California. (I object to the item of $450,000 in section 1 and reduce the amount to $390,000. With this reduction I approve the bill. Dated June 17, 1929. C. C. Young, Governor.) The people of the State of California do enact as follows: Section 1. Out of any money in the state treasury not otherwise appropriated, the sum of four hundred fifty thousand dollars, or so much thereof as may be necessary, is hereby appropriated to be expended by the state department of public works in accordance with law in conducting work of exploration, investigation and preliminary plans in furtherance of a coordinated plan for the conservation, development and utilization of the water resources of California including the Santa Ana River and its tributaries, the Mojave River and its tributaries, and all other water resources of southern California. Sec. 2. The department of public works, subject to the other provisions of this act, is empowered to expend any portion of the appropriation herein provided for the purposes of this act, in coopera- tion with the government of the United States of America or in coop- eration with political subdivisions of the State of California; and for the purpose of such cooperation is hereby authorized to draw its claim upon said appropriation in favor of the United States of America, or the appropriate agency thereof for the payment of the cost of such portion of said cooperative work as may be determined by the depart- ment of public works. Sec. 3. Upon the sale of any bonds of this state hereafter author- ized to be issued to be expended for any one or more of the purposes for which any part of the appropriation herein provided may have been expended, the amount so expended from the appropriation herein provided shall be returned into the general fund of the state treasury out of the proceeds first derived from the sale of said bonds. (13) FOREWORD This report is one of a series of bulletins on the State Water Plan issued by the Division of Water Resources pursuant to Chapter 832, Statutes of 1929, directing further investigations of the water resources of California. The series include Bulletin Nos. 25 to 36, inclusive. Bulletin No. 25, "Report to Legislature of 1931 on State Water Plan," is a summary report of the entire investigation. Prior to the studies carried out under this act, the v^^ater resources investigation had been in progress more or less continuously since 1921 under several statutory enactments. The results of the earlier work have been published a*s Bulletin Nos. 3, 4, 5, 6, 9, 11, 12, 13, 14, 19 and 20 of the former Division of Engineering and Irrigation, Nos. 5, 6 and 7 of the former Division of Water Rights and Nos. 22 and 24 of the Division of Water Resources. The full series of water resources reports prepared under Chapter 832, twelve in number are : Bulletin No. 25 — "Report to Legislature of 1931 on State Water Plan." Bulletin No. 26 — "Sacramento River Basin." Bulletin No. 27 — "Variation and Control of Salinity in Sacra- mento-San Joaquin Delta and Upper San Francisco Bay." Bulletin No. 28 — "Economic Aspects of a Salt Water Barrier Below Confluence of Sacramento and San Joaquin Rivers." Bulletin No. 29 — "San Joaquin River Basin." Bulletin No. 30— "Pacific Slope of Southern California." Bulletin No. 31 — "Santa Ana River Basin." Bulletin No. 32— "South Coastal Basin." Bulletin No. 33 — "Rainfall Penetration and Consumptive Use of Water in Santa Ana River Valley and Coastal Plain." Bulletin No. 34 — "Permissible Annual Charges for Irrigation Water in Upper San Joaquin Valley." Bulletin No. 35 — "Permissible Economic Rate of Irrigation Development in California." Bulletin No. 36—' ' Cost of Irrigation Water in California. ' ' This bulletin presents the results of an intensive study of the occurrence and variation of salinity in the upper San Francisco Bay and Sacramento-San Jotiquin Delta channels, and the basic factors of stream flow and tidal action affecting salinity and their relation to its variation. Finally, there is presented a proposed plan for the control of salinity by stream flow to prevent harmful saline invasion into the delta and maintain a dependable and adequate fresh-Avater supply in the delta channels for the full consumptive demands of the delta; and provide a dependable source for diversion of fresh-water supplies, now or hereafter made available in the delta, for the needs of industrial, municipal and /igricultural developments in the upper bay region. (14) CHAPTER I INTRODUCTION, SUMMARY AND CONCLUSIONS The waters of San Francisco Bay are a combination of the salt water of the ocean which enters the bay through the Golden Gate, and the fresh water of the Sacramento and San Joaquin rivers and local streams of the San Francisco Bay Basin which discharge into the bay. The salinity of the water resulting from this combination is extremely variable both geographically and during different periods of the year, and depends upon the amount of fresh water discharged by the streams. The more saline waters are found in the lower bay nearest the ocean, the fresher waters in the upper bays and tidal estuaries and channels through which the fresh water enters, while in between are found gradations from salt to fresh water. When the streams are in flood, the upper bays and channels are often filled with fresh water and, during extreme floods, it is stated that fresh water has been found even as far down as the Golden Gate. When the flow of the streams is small during the summer and fall months, the water in the upper bays and tidal channels up to the lower reaches of the Sacramento and San Joaquin rivers generally becomes saline and remains so until the first floods of the succeeding winter season. The invasion of saline water into the upper bay as far as the lower end of the Sacramento-San Joaquin Delta is a natural phenomenon which has occurred annually, at least as far back as historical records reveal. Under conditions of natural stream flow before upstream irri- gation and storage developments occurred, the extent of saline invasion and the degree of salinity reached was much smaller than during the last ten to fifteen years. However, the evidence of all available infor- mation, as presented hereafter, points to the conclusion that saline water from the bay has advanced as far upstream as the A'icinity of Collinsville and Antioch, causing a noticeable degree of salinit}^ of ten parts or more of chlorine per 100,000 parts of water at some time each year during the period of low stream flow. In former years before extensive developments in agriculture and industry had been made in the upper bay and delta region, it was of small importance and received little, if any, attention. However, it was known by many of the early inhabitants of the Suisun Bay and lower delta region. Beginning in 1917, there has been an almost unbroken succession of subnormal years of precipitation and stream flow which, in com- bination with increased irrigation and storage diversions from the upper Sacramento and San Joaquin RiA'er systems, has resulted in a degree and extent of saline invasion greater than has occurred ever before as far as known. These abnormal saline invasions not only have curtailed irrigation diversions and affected crop production and land values in the delta but also have reduced considerably the diver- sions of fresh-water supplies from the lower river and upper bay ( 15 ) 16 DIVISION OF WATER RESOURCES channels by the industries in the upper Suisun l^ay area, thus increas- ing the difficulties and cost of obtaining industrial fresh-water supplies. The seriousness of this situation resulted in the initiation of investiga- tions of salinity by the State, leading to the present investigation and report. Area of Salinity Investigations. The area in which the investigations of salinity have been made einhi-aces the Sacramento-San Joaquin Delta and Suisun and San I'ablo baj's. This is shown on Plate I, "Area of Salinity Investiga- tions and Related Water Resources and Developments in California." The more extensive studies have been made within the delta area and Suisun Bay, where the invasion of saline water during recent years has assumed great importance because of the serious effect upon the adjacent industrial and agrieiiltural developments. However, in order to obtain moi-e complete data on variation of salinity and determine the factors controlling the same, the investigation has been extended into San Pablo Bay area. Thus, there is embraced within the area of inves- tigation all of the waters of the upper bay and delta channels in which the cyclic variations of salinity annually occur. It is within this area that the natural phenomenon of annual invasion and retreat of salinity takes place. The geographical relation of the area of salinity investigations to the physiographical features of the State and, especially, the tributary stream systems is shown on Plate I. The magnitude of water resources naturally tributary to the delta and upper ba.y region is relatively large. Into this area drains the run-off from 32,000 ^ square miles of mountain and foothill land or 39 per cent of the entire mountain and foothill catchment area of the State. The two great river systems, the Sacramento and San Joaquin, which drain most of this area, flow through a network of ciuinnels forming a common delta and finally combine to discharge through a common mouth into the upper or east- erly end of Suisun Bay. It is the discharge of these streams that has the most profound effect upon the qualitj'' of the waters in upper San Francisco Bay. When these streams are in flood, Sui.sun Bay is usually made fr(>sh and San Pablo Bay often becomes partly fresh. On the other hand, Avh(>n these streams have ]-eacIied tiieir low stage in the summer and fall months each season, the salt waters from the lower bay gradually advance upstream and mix with the ffesh-M'ater inflow and there results the annually recurring phenomenon of saline invasion. It is evident that any irrigation or storage developments on these tribu- tary stream systems above the delta, involving a change in regimen of stream flow and, especially, a reduction in flow, directly modify the natural interrelations of salinity and stream flow in the delta and upper bay channels. The existing major storage reservoirs as of 1929 are shown on Plate T. Present irrigation developments diverting water from the Sacramento and San Joaquin rivers are far too numerous and extensive to illustrate properly on this map, but a large area of lands in the Sacramento and San Joaquin valleys is irrigated from these streams, diverting most of the low water flow. Looking to the future development of water resources on these streams, it may be ' Does not include Kings River. 1 2 1- 3 4 5 6 7 « 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 \ 16 DIVISION OF WATER RESOURCES channels by the industries in tlic upper Suisun Bay area, thus increas- ing the difficulties and cost of obtaining industrial fresh -water supplies. The seriousness of this situation resulted in the initiation of investiga- tions of salinity by tlic Slate, leading to the prosout iiuestigation and report. Area of Salinity Investigations. The area in which the investigations of salinity have been made embraces the Sacramento-San Joaquin Delta and Suisun and San Pablo bays. This is shown on Plate I, "Area of Salinity Investiga- tions and Related "Water Resources and DeA'elopments in California." The more extensive studies have been made within the delta area and Suisun Bay, where the invasion of saline water during recent years has assumed great importance because of the serious effect upon the adjacent industrial and agriciiltural developments. However, in order to obtain more complete data on variation of salinity and determine the factors controlling the same, the investigation has been extended into San Pablo Bay area. Thus, there is embraced within the area of inves- tigation all of the waters of the upper bay and delta channels in which the cyclic variations of salinitj- annually occur. It is Avithin this area that the natural phenomenon of annual invasion and retreat of salinity takes place. The geographical relation of the area of salinity investigations to the physiographical features of the State and, especially, the tributary stream systems is shown on Plate I. The magnitude of water resources naturally tributary to the delta and upper bay region is relatively large. Into this area drains the run-off from 32,000 ^ square miles of mountain and foothill land or 39 per cent of the entire mountain and foothill catchinent area of the State. The two great river systems, the Sacramento and San Joaquin, which drain most of this area, flow through a network of channels forming a common delta and finally combine to discharge through a common mouth into the upper or east- erly end of Suisun Bay. It is the discharge of these streams that has the most profound effect ujion the qualit}' of the waters in upper San Francisco Bay. When these streams are in flood, Suisun Bay is usually made fr(»sh and San Pablo Bay often becomes partly fresh. On the other hand. Avhon these streams have i-eiu-hed their low stage in the summer and fall months each season, the salt waters from the lower bay gradually advance upstream and mix with the fi'esh-water inflow and there results the annually recurring phenomenon of saline invasion. It is evident that any irrigation or storage developments on these tribu- tary strcvun systems al)ove the delta, involving a change in regimen of stream flow and, especially, a reduction in flow, directly modify the natural interrelations of salinity and stream flow in the delta and upper ])ay channels. The existing major storage reservoirs as of 1929 are sjiown on l*late I. Present irrigation developments diverting water from the Sacramento and San Joaquin rivers are far too numerous and extensive to illustrate properly on this map, but a large area of lands in the Sacramento and San Joaquin valleys is irrigated from these streams, diverting most of the low water flow. Looking to the future development of water resources on these streams, it may be > Does not Include Kings River. STJIRAM OAOl.VO STATIONS 1 SHf-rnmerno Hlver - -..St Ji-llyn Fprr>- nc nr Rrd Kliifr ;! Dorr ("roelt . . ■ -.jiour Vino I Fakii 1 . i-oMimiieB ntVM- — -..11 MIHilenn Bar . M'lkdumnc niv«r nmr Thornton !>ty Crpck ...ncur tialt Mokcliimno River ...at ttVo01>rl.lBt Miiktflunino River — ncnr t'lfmentn ■ i-iiinv^ran Riv»r-- ---at Joiiiiy LInd .SlaiildliiuH RIvor -- ...nciir KnlBhlB F.-rry -1 Tuulumiic Rlvor. -.m- nr l.a Crungn .1 San Jummhi Rlvor ...nc ir Ni'wmun j2 MiTcciI Rlvvr ._ ...IK nr Mcroi-d FilIIh 23 Snn Ji>iiqiilii Rlvor ...iionr Frlnnt 24 Sun Joaquin Rtvcr ur VcrnollB 25 Yolo By-]WtM ...nt LIcbon 26 Huiali CrvPk — jit WlnttifH 27 CncliP Orcuk — nt Yolo JS Stiiny Cri-k ...ncnr UrlBnd /' ^ ■', / fe ^ /V . 1 - ,, ^>c \ \ LEGEND ■ Area of im'estigaliun i^ ICxislinj^ reservoirs 1^ Proposed reservoirs • Slrcain gaging stations Nunfcer lifiairs Ig ijmbol fufti^ In till ji lep oT "wp \ X \ vf^a ^""^' Q -. \ \Ui:,\ OK SAl.lMTY INVKSTIGATIONS AM) m.iArKh \VAT1;H liKSOl'RCKS AND DEVELOPMKNTS lAl.iroUNiA VARIATION AND CONTROL OF SALINITY 17 expected that additional storage reservoirs and municipal water supply, irrigation and power systems will be constructed as the needs increase with the growth of the State. Plate I shows the major storage reser- voirs on these streams as proposed in the State Water Plan.* In addition, there doubtless will be numerous other reservoirs constructed by private and public agencies. The water resources developments in past years have affected salinity conditions in the delta and upper bay region and future developments may be expected to modify them still farther. The developments and interests affected by saline invasion include the agricultural lands of the Sacramento-San Joaquin Delta and the industries, municipalities, and agricultural lands adjacent to Suisun and San Pablo Bays. The location and extent of these developments are shown on Plate II, "Agricultural and Industrial Developments in the Sacramento-San Joaquin Delta and Upper San Francisco Bay Regions and Related Water Resources and Developments of Northern California." Inasmuch as the investigations of the variation and con- trol of salinity are particularly related to these developments, it is of interest to consider the character and magnitude of their operations and activities, and the physiographieal features of the channels and bays adjacent thereto. These are briefly described in the following paragraphs, but a more detailed description of the developments and activities of the upper bay and delta regions is presented in another report.** Sacramento-San Joaquin Delta — The area known as the Sacramento- San Joaquin Delta is situated in the lowest part of the Great Central Basin of California, midway between the Sacramento and San Joaquin valleys. (See Plates I and II). In its original state of nature, it consisted of swamp and overfloAV lands gTadually built up through the ages b.y accumulations of decayed vegetation and deposits of silt brought down by the Sacramento and San Joaquin rivers. These swamp lands were covered with various types of aquatic vegetation, trees and grasses. Sycamores, willows and cottonwoods lined the banks of the Sacramento River and its branch channels while the interior of the islands and lower-lying lands of the Sacramento Delta supported a dense growth of tules and other aquatic plants. In the San Joaquin Delta and lower Sacramento Delta where the peat lands are situated, willows occasionally lined the banks of the channels or occurred inland in clumps. Most of the islands in the San Joaquin Delta were covered largely with various grasses and occasional clumps of tules and similar aquatic plants. The Sacramento and San Joaquin rivers, upon reach- ing the delta, spread out into a network of channels separated by islands in a typical delta formation, and finally discharge their waters through a common mouth into Suisun Bay, Mdiich forms the north- easterW arm of San Francisco Bay. The delta has a gross area of 487,500 acres, roughly 20 miles wide by 50 miles long. It extends up the Sacramento River as far north as the city of Sacramento and up the San Joaquin River as far south as the Mossdale Bridge on the Lincoln Highway near the town of Lathrop. * Bulletin No. 25, Report to Legislature of 1931 on State Water Plan, Division of ^Vater Re.sources, 1930. ** Bulletin No. 28, Economic Aspects of a Salt "Water Barrier below Confluence of Sacramento and San Joaquin Rivers, Division of Water Resources, 1931. 2—80995 18 DIVISION OF WATER RESOURCES Its easttu-ly boundary skirts the citj' of Stockton and lies about seven miles west J'roni Lodi and Gait. Its -westerly end at the junction of the rivers is near Antioch and Collinsville. A large portion of the land lies at an elevation at or below mean sea level. Within the delta are 421,000 acres of highly productive agricul- tural lands, consisting of sediment and peat soils, which have been gradually reclaimed at great cost over a period of 75 years of progres- sive reclamation development. At the present time probablj'^ all lands within the delta which are feasible of reclamation have been fully reclaimed and are now being farmed. In 1929, 350,000 acres of land in the delta were in crops, such as asparagus, corn, potatoes, sugar beets, beans, celery, pears, peaches, alfalfa, wheat and barley. The annual value of crops produced in the delta in 1929 is estimated to have been about $30,000,000. The taxable wealth of the delta area is approximately $45,000,000. The network of channels which separate the islands in the delta is of great importance to the area. The channels not only are the source of water supply used for irrigation of crops, but they provide efficient and economical water transportation for crops, equipment, materials and supplies. In the case of some of the islands, it is the only form of transportation now available. These channels, which have an aggregate length of about 550 miles and an open water area of about 38,000 acres, are all navigable for river craft, which transport a large part of the freight handled, to and from the nearest railroad loading points, or to and from bay and river points. With the completion of the Stockton Ship Canal, now under construction, it will be possible for deep-draft ocean-going vessels to navigate as far as Stockton. Suisiin Bay Area — Suisun Bay, into which the Sacramento and San eloaquin rivers jointly discharge immediately west of the delta, is a rela- tively shallow body of water, with two main arms separated by a penin- sula and close-lying islands extending out from the north shore. Its southerly arm is practically a continuation of the river, extending along the south shore for about ten miles and varjdng in width from one to two miles. The southerly arm includes the deeper waters and the mail! navigation channels. The northerly arm extends in a northeasterly direction fi'om the lower end of Suisun Baj^ a distance of ten miles and spreads out at its upper end into a broad, shallow basin locally kno^vn as Grizzly Bay. The total area of open water in Suisun Bay below the mouth of the rivers is about 30,000 acres. Large (juantities of silt and debris brought down by the rivers have been deposited in Suisun Bay and the gradual accumulations through the passage of time have resulted in diminishing the area and depth of the bay. Dredging operations are required from year to year to keep the navigation channels open. Adjoining the north shore of Suisun Bay is an extensive area of marshlands aggregating 58,700 acres, consisting of numerous islands separated by a network of channels. One of these main channels, known as Montezuma Slougii, extends in a circular path for about 20 miles from the upper end of the northerly arm of Suisun Bay to join the Sacramento River just below Collinsville. This channel thus forms a secondary outlet to carry the river discharge into the bay. Suisun Slough is another important channel, which meanders northerly to a dead end near the cities of Suisun and Fairfield. PLATE II LEGEND ■•Delta agrictiltural lands 0iiS2 Upper Bay marsh lands par- tially developed to agricidt-are fi^^ Upper Bay agricultural "uplands below 150 ft. contour Upper Bay industrial area Proposed reservoirs ^s_f3^ Existing reservoirs •5 Stream gaging stations Note: Number adjacent to symbol refers to list at top of map. AGRIGUi.TlRVI. AND INDUSTRLU DK\EIX)PMI:NTS tN THK SACRAMENTO AND SM JOAQUIN DELTA AND UPPER SAN FRANCISCO BAY REGIONS AND RELATED WATER RESOURCES AND DEVELOPMENTS OF NORTHERN CALIFORNIA SCALE OF MILES 8 8 ;> — p 18 DIVISION OF WATER RESOURCES Its easterly boundary .skirts the city of Stockton and lies about seven miles west from Lodi and Gait. Its westerly end at the junction of the rivers is near Antioch and Collinsville. A large portion of the land lies at an elevation at or below mean sea level. Within the delta arc 421,000 acres of highly productive agricul- tural lands, consisting of sediment and peat soils, which have been gradually reclaimed at great cost over a period of 75 years of progres- sive reclamation development. At the present time probably all lands Avithin the delta which are feasible of reclamation have been fully reclaimed and are now being farmed. In 1929, 350,000 acres of land in the delta were in crops, such as asparagus, corn, potatoes, sugar beets, beans, celery, pears, peaches, alfalfa, wheat and barley. The annual value of crops produced in the delta in 1929 is estimated to have been about $30,000,000. The taxable wealth of the delta area is approximately $45,000,000. The network of channels which separate the islands in the delta is of great importance to the area. The channels not only are the source of water supply used for irrigation of crops, but they provide efficient and economical water transportation for crops, equipment, materials and supplies. In the case of some of the islands, it is the only form of transportation now available. These channels, which have an aggregate length of about 550 miles and an open water area of about 38,000 acres, are all navigable for river craft, which transport a large part of the freight handled, to and from the nearest railroad loading points, or to and from bay and river points. With the completion of the Stockton Ship Canal, now under construction, it will be possible for deep-draft ocean-going vessels to navigate as far as Stockton. Suisun Bay Area — Suisun Bay, into which the Sacramento and San Joaquin rivers jointly discharge immediately west of the delta, is a rela- tively shallow body of water, with two main arms separated by a penin- sula and close-lying islands extending out from the north shore. Its southerly arm is practically a continuation of the river, extending along the south shore for about ten miles and varying in width from one to two miles. The southerly arm includes the deeper waters and the main navigation channels. The northerly arm extends in a northeasterly direction from the loAver end of Suisun Bay a distance of ten miles and spreads out at its upper end into a broad, shallow basin locally known as Grizzly Bay. The total area of o])en water in Suisun Bay below the mouth of the rivers is about 30,000 acres. Large quantities of silt and debris brought down by the rivers have been deposited in Suisun Bay and the gradual accumulations through the passage of time have resulted in diminishing the area and depth of the bay. Dredging operations are required from year to year to keep the navigation channels open. Adjoining the north shore of Suisun Bay is an extensive area of marshlands aggregating 58,700 acres, consisting of numerous islands separated by a network of channels. One of these main channels, known as Montezuma Slough, extends in a circular path for about 20 miles from the upper end of the northerly arm of Suisun Bay to join the Sacramento River just below Collinsville. This channel thus forms a secondary outlet to carry the river discharge into the bay. Suisun Slough is another important channel, which meanders northerly to a dead end near the cities of Suisun and Fairfield. STRBAM GAGING STATIONS Eacnmcnto River •( Jellys Ferry e«crsmenIo RlT«r new Rrf BtuO i>r*t Creek near Vina Kra,lter River at OrovIUe Yuba RIvor. at Smartavllla Benr Rlv« . — . ftt Van Trent Featlier River -- at Nicolaua Sacramento River at Kniehie lAndlng Sacramento River at Verona RBor«f)ienlo River at Sacramento American River at H SI. BrlOgr. neB kmcrlcan River ai Patroaks Cr»ufnt)«« River at Mlcblgan Bar M'lkelumre Rlv*r near Thoroton Dry Creek near Gall Mr.Kelumne River.- ..at Woodbrldge Mr>t(«Iunine Rlv«r near ClementB Calaveras River, .at Jenny Lrind iTUiiIslaus River. near Knt^la Ferry ?4n Joaquin River near Newman Sftl> Joaquin River near Vemalli Tolo By-pua at Lisbon F'>nall Credt at W inters Cache Creek . at Yolo Stony Creek near Orland Sacriiraenio LEGEND ■ Urlta agriiMiltiiral lajids ii Upper Bav rnarsh lands par- tiaJIv (Ipvfloppd to a^ndtiire V^vT Bay agrirultnral uplands bplow 150 ft. contour ^* I'ppPT Bay indu^rial ai^/a ^^^ Proftosed reservoirs! }f^ Existing TPServoirs *a Stream ^a^ing station? OCt:A!' \r,Kiciii;n lui. and industrlu dkaki-opmi^nt^ IV TIIK SACRVMKNTO ASD SW.JOAOL'IN DKI.TA I'Pl'KR S.VN FI{A\aS( O BAY RIXWONS ANli RTLATUFt vvA'n;it ui:s<>iK(Es and de\'elopmel\ts NORTHERN CAl.lFDRXIA StAi.K OF MILKS 4 VARIATION AND CONTROL OF SALINITY 19 The marshlands north of Suisun Bay have been largely reclaimed by levees, the area within levees aggregating- 44,600 acres. However, only a small portion, 5000 acres, of the leveed land is farmed at present. Agricultural development has been largely unsuccessful, due to the salt-marsh character of the soil and the brackish quality of the water supply which predominates during most of each year in the adjacent channels. The leveed lands are now occupied largely by duck hunting preserves. North of the marshland area of Suisun Bay is an upland agri- cultural area, comprising hill and valley lands. Of the entire area between the border of the marshlands and the 150-foot contour, about 35 per cent is now cultivated. There is a considerable acreage of orchards and vineyards and larger areas in grain and hay. ]\Iueh of the orchard area is irrigated from wells. The ground water supplies are generally limited to the valley areas of tributary local streams, and the available supply is practically all utilized on the present irri- gated area. Along the south shore of Suisun Bay, there is a large industrial development extending from Antioch to jMartinez. Much of this development centers around the city of Pittsburg, situated at the lower end of New York Slough. Other large industrial plants are scattered at various locations on or near the bay shore from Pittsburg to Martinez. The low-lying marsh areas skirting the shore are for the most part unreclaimed and uncultivated. Hay and grain are grown on most of the higher bordering uplands. The upland area extending from Antioch easterly to Knightsen is largely devoted to orchards and vineyards, with some grain and hay, most of which is dry farmed. South of Martinez, the Ygnaeio and Clayton valleys open out into a broad upland area of comparatively flat land. This area is largely devoted to agriculture, including dry farming and irrigation by wells. Over one-third of the area is in orchards and vineyards and a some- what smaller area in hay and grain and various field crops. Ground water supplies are limited in quantity and already are being over- drawn. Carquinez Strait Area — Suisun Bay is joined to the next large bay to the west, San Pablo Bay, by Carquinez Strait. This is a deep channel averaging about three-quarter miles in width and about seven miles long. It extends througli a narrow rift in the liills which rise steeply and abruptly from both shore lines for the greater part of its course. The area along the south shore is largely occupied by railroad and industrial developments, Avith the industrial city of Crockett lying near its westerly end. The area along the north shore is but little developed, except at Benicia which is situated near its easterly end, and at which the United States Arsenal is located. San Pablo Bay Area — San Pablo Bay is considerably larger in size than Suisun Bay, being roughly ten miles wide by twelve miles long and having an open water area of 73,000 acres. Like Suisun Baj^ it is com- paratively shallow over most of its area, except for navigation channels which are maintained at desired depths by more or less constant dredg- ing operations. The finer and lighter silts brought down by the river floods and by local streams find their way into San Pablo Bay and their deposits, under the action of tidal movement, have formed large areas of 20 DIVISION OF WATER RESOURCES shallow water and mud flats extending out foi- tii-eat distances from the sliore line. Tiie area alonjr the sontheaster]\- shore of San Pablo Bay from Oh'uni on the north to the city of Iiiehnioiid on tlie south includes several larj;e iiidustrios and a few small towns. There is some agi'icultural development, but it is not extensive, consistinir mostly of dry farming Of g:rain and hay on the rolling? hill lands. Some few .small areas of truck jiardens irrigated by wells are farmed in the fiat valley lands of tributary streams. Nortli of San Pablo Bay, there is a large area of marshlands aggre- gating 58,600 acres. Several streams, most important of which are the Xapa River, and Sonoma, Petaluma and Novato creeks, discharge their waters through channels extending through these marshlands into the bay. There are numerous connecting channels between the Napa River and Sonoma Creek, which divide the intervening mar.sh area into several islands. A considerable portion of this marshland area is reclaimed by levees and mucli of it is farmed. Of 45,400 acres of leveed land, 24,000 acres are now farmed, mostly to hay and gi'ain. Above the marshland areas, the adjacent uplands, especially in Na]>a, Sonoma, Petaluma and Xovato valleys, are largely devoted to agriculture including chiefly, orchards, vineyards and poultry raising. Most of the land is dry farmed and only a small area is now irrigated. The city of Vallejo is situated at the lower end of the Napa River at the northeast corner of San Pablo Bay. Directly opposite Vallejo is located the T-nited States Navy Yard on Mare Island. The cities of Napa and Petaluma are situated near the upper boundary of the marsh- land area north of San Pablo Bay. Each of these cities has several industries. Developments and Interests Affected by Saline Invasion — Only a portion of the develoi)ments and interests in the upi)er bay and delta regions is or has been affected by saline invasion and, especially, by the change in salinity conditions during the last ten to fifteen years. These include the agricultural lands in the Sacramento-San Joaquin Delta and adjacent delta uplands, and, to a minor extent, the marshlands adjacent to Suisun Bay ; and some of the industries and public water supply .systems in the upi)er Suisun Bay area. Irrigation supplies for the delta lands and adjacent uplands are obtained from the delta channels. The greater degree and extent of saline invasion in certain years since 1917 have resulted in the curtailment of irrigation diver- sions for a portion of the delta and adjacent upland area. The marsh- lands adjacent to Suisun Bay have been affected less adversely by the greater saline invasions of recent >'ears, because, as revealed by avail- able historical infornuition, fresh water was never available in the adjacent channels throughou.t the irrigation season as it was in the delta channels in former years. However, the period of availability of fresh watei" in the Suisun Bay channels has been reduced to some extent in recent years, thus cui-tailing irrigation on the limited area farmed, and increasing the difficulty of removing salt from the marsh soils because of the greater lack of fresh-water supplies for leaching purposes. The industries using fresh-water supplies from the river to any lai-ge extent are mostly confined to the Antioch-Pittsburg district, although some fresh-water supplies have been obtained from the river VARIATION AND CONTROL OF SALINITY 21 and bay by industries as far down as ^Fartinez. In 1929 the industries used an average over the year of about seven million gallons per day of fresh water for boiler and process purposes by private diversions from the river. Over 80 per cent of this use was by industries in the Antioch-Pittsburg district. The industries with private diversion works have no storage facilities and hence can not obtain fresh-water supplies from the river or bay for boiler and process uses during saline invasion. Due to the greater degree and duration of saline invasion in recent years, these industries have been curtailed in their use of the river and upper bay channels as a source of fresh-water supply, and have been required to obtain more of their fresh-water supplies than in former years from other sources, entailing greater expense. Consider- able supplies have been developed from local underground sources but this source of supply is limited in quantity and of doubtful depend- ability because of a tendency for the well waters becoming polluted with saline water infiltrating from the adjacent baj^ and river channels. The California-Hawaiian Sugar Refining Corporation, located at Crockett, formerly obtained a large part of its fresh-water supply by means of barges filled upstream from the plant wherever fresh water w^as available. Because of the increased distance of travel to obtain fresh water, due to the more extensive saline invasions of recent years, the comjDany obtained w^ater by barge, from Marin County beginning in 1920, and more recently (1981) has completed a new private water supply system, developing underground water in the lower end of Napa Valley and piping the same to Crockett, which is expected to supply its fresh-water demands. A large part of the water used by the industries in the upper bay region is for cooling and condensing purposes. The use of saline water for this purpose is satisfactory and little advantage would be gained if the w'ater were fresh. Salt-resisting equipment is required to prevent abnormal corrosion but the additional cost of such equipment does not greatly increase the expense of cooling water and the cost of cooling w^ater per 1000 gallons is relatively small. The public water supply systems now using the river as a source of fresh-water supply include those of the city of Antioch and a public utility serving domestic and industrial consumers in upper Contra Costa County. These two public water supply systems are using an average of two to three million gallons per daj^ from the river. Both have storage reservoirs, which are filled when the water in the river is fresh to provide a supply to meet the demands during the period of saline invasion. In former years, Pittsburg obtained its domestic and municipal supply from New York Slough, a branch of the lower river. However, this source of supply was abandoned in 1920 in favor of supplies from wells, because the quality of the water in New York Slough was unsatisfactory due to saline invasion and sewage pollution. The remaining developments and interests in the upper bay region have not been affected thus far by saline invasion in regard to water supply, because the river and bay channels have not been used as a source of fresh-Avater sujiply. HoAvever, the studies presented in other reports* show that the ultimate water requirements for industrial, * Bulletin No. 25, Report to Legislature of 1931 on State Water Plan, Division of "Water Resources, 1930. Bulletin No. 28, Economic Aspects of a Salt AVater Barrier below Confluence of Sacramento and San Joaquin rivers, Division of "Water Resources, 1931. 22 DIVISION OF WATER RESOURCES municipal and agricultural use in the upper bay region will necessitate the importation of supplies from some suitable source to supplement the local water resources which are capable of economic development. The nearest source of supply would be the lower Sacramento and San Joa(iuin rivers. The studies of water su])ply, yield and demand in the operation of the initial and ultimate developments of the State Water Plan show that most of the water supply required to be imported to the upper San Francisoo Bay region could be furnished from this source. Therefore, the industrial, municipal and agricultural developments adjacent to Suisun and San Pablo bays are directly interested in the investigation of salinity, and particularly in the determination of a means of controlling saline invasion in such a w^ay that water supplies now available or hereafter made available in the lower Sacramento and San Joaquin rivers would be maintained fresh at all times for diversion to supply the future needs of the upper bay region. Previous Investigations. The first investigations of salinity by the State were made in the fall of 1916 when a preliminary study and a few samples and analyses of the water were made by the State Water Commission. At this time, the potential seriousness of the salinity problem began to be recognized. Again in 1918 and 1919 some samples and analyses of the water at Antioch were made by the State Board of Health and the State Water Commission. However, the investigation of salinity in the upper bay and delta channels was not started on any extensive scale until 1920. The dry years of 1917 to 1919, combined with increased upstream irriga- tion diversions, especially for rice culture in the Sacramento Valley, had already given rise to invasions of salinity into the upper bay and lower delta channels of greater extent and magnitude than had ever been known before. At the beginning of 1920, it was evident that another dry year was impending Avhieh might result in serious water shortage and a po«sibly greater saline invasion. Accordingly, in February 1920, the State Water Commission and the State Engineer in cooperation with an organization of the delta land 0A\Tiers, designated the Kiver Lands Association, arranged a cooperative program for a detailed investigatioii of the salinity conditions. Funds were provided partly by the State and partly by the River Lands Association. The State Water Commission furnished most of the ]iersonnel and equipment. Actual field work was started on May 25, 1920. Salinity observation stations, 28 in number, were establishetl at various points in the delta channels and a regular schedule initiated for sampling of water. The samples were tested for salinity in terms of chlorine content by stand- ard titration methods. The Avater samples were generally taken about every two days at about the time of high tide. In addition to these regular ob.servation stations, a few sjiccial surveys were made to deter- mine the variation of salinity through a tidal cycle and also the varia- tion with depth, but these were not extensive enough to come to any definite conclnsions. However, it was discovered that the highest degree of salinity usually occurred abont one and one-half to two hours fol- lowing hi<:h-high tide and the minimum salinity about the same time after low-low tide. In addition to the investigations made by the State in 1920, a large amount of additional investigational work was done by VARIATION AND CONTROL OF SALINITY 23 engineers employed by the plaintiffs and defendants in the "Antioch" suit. The Antioch Suit — The "Antioch" suit was the direct result of the impending water shortage of 1920 and the menace to the delta interests of a serious saline invasion. It was preceded by a series of meetings and discussions among the water users of the upper valley and the, delta, which failed to reach any agreement as to the conflicting claims for water. The suit, filed on July 2, 1920, was instituted by the city of Antioch under claim of riparian right against the upper irrigation appropriators of the Sacramento Valley, seeking to enjoin their diver- sions of water. The hearing upon the plaintiff's application for a temporary injunction was started on July 26, 1920, in the Superior Court of Alameda County before Judge A. F. St. Sure, and continued over a period of about three months. The temporary injunction was granted and the defendants appealed from the order therefor and secured its reversal by the Supreme Court. In its decision, the Supreme Court held that Antioch did not have a riparian right to the use of water within the corporate limits of the city but that its rights in the San Joaquin River were those of a diverter and user of water thereof for beneficial purposes and nothing more. It further held that an appropriator or diverter of fresh water from a stream at a point near its outlet to the sea does not, by such appropriation, acquire the right to insist that subsequent appropriators above should leave enough water flowing in the stream to hold the salt water of the incoming tides below his point of diversion. The actual outcome of the suit and the final decision rendered is not of very great importance to this study, although, at the time, it was considered a. great victory for the upper irrigationists and equally a great loss to the city of Antioch, and more particularly to the delta land owners who were in fact the real force behind the initiation and prosecution of the suit. Of greatest importance to the State and all of the interests involved and affected by the salinity conditions is the fact that the filing and prosecution of the Antioch suit forceably called to the attention of the public the seriousness of the salinity problem confronting the upper bay and delta interests. It became evident to all concerned, and especially to the State authorities, that it was necessary and essential that a complete investigation be made of the salinity con- ditions with the object of finally determining, if possible, remedial measures to control the invasion of salinity. It was realized that it probably would be necessary to continue the gathering of data for several years before there would be sufficient information for a detailed study. Investigations During Period 1921 to 1929 — Following 1920, the investi- gations of salinity were carried on under the State Water Commission and its successor, the Division of Water Rights, in much the same manner as during 1920. Regular salinity observation stations were maintained and samples taken at regular intervals in accordance with a prearranged schedule. The samples were taken only during the summer and fall months when salinity of magnitude was present in the delta channels. Prior to 1923, the testing of the salinity samples was done by a specially employed chemist in the office of the State Division 24 DIVISION OF WATER RESOURCES of Water Rights (formerly the State Water Commission). Beginning witli 1928, however, all testing of salinity samples was done by the eheiuist in the State Highway Testing Tiaboratory. The years 1921, 1922 and 192.1 Avere fairly normal rnn-off years and the salinity condi- tions and extent of saline invasion were not anywhere near as severe as in 1920. However, in the year 1924, following one of the driest seasons of precipitation and run-off on record in California in the last sixty years, tiie number of observation stations was greatly increased in order to cover in detail the greatly increased area in the delta into which saline water advanced during the summer and fall of that year. Regular salinity samples were being taken at 32 stations by the middle of August. Beginning with the 1924 season, the salinity investigations were handled by the Sacramento-San Joaquin Water Supervisor. This office of water supervisor was created in 1924 as a result of a series of conferences, beginning in 1923 and participated in by representatives of the delta and the upper irrigationists and business men of the Sacra- mento Valley, which culminated in the Sacramento River Problems Conference held on January 25 and 26, 1924. This meeting was called by the State Division of Water Rights in cooperation with the Sacra- mento Chamber of Commerce. As a result of this first Sacramento River Problems Conference, a permanent committee was created, called the "Sacramento River Problems Committee," which has functioned up to the present time. In realizing the impending serious water shortage in 1924, this jiermanent committee arranged a contract with the State Division of Water Rights whereby the division agreed to carry on necessary work of supervision and collection of records through the agency of a Avater supervisor. Necessary funds to carry out the program, including detailed measurements of stream flow and diversions, were raised bj' the committee through voluntary sub- scription. In addition to the detailed measurements of stream floAv and diver- sions, the Sacramento-San Joa(|uin Water Supervisor has been directly in charge of all field Avork on salinity investigations since 1924. Salinity bulletins giving the detailed records of salinity in the delta have been sent out at periodic intervals during each season to the delta land OAvners and the information luis been of material assistance to them in ])]anning and carrying out their irrigation and agricultural operations. Beginning Avith 1926, regular salinity observation stations were estab- lished at points in Suisun and San Pablo baA's and, at the same time, seven of the loAvor stations were maintained throughout the year. This enlargement of tlie territory covered by the salinity observations has furni.shed data of great value in carrying out the present studies. The detailed records of salinity and stream flow and mea.surements of use of Avater in the (K'lfa, Avhich Avere gathered from 1924 to 1929. inclusive, comprise the more important i)liysieal data for tlie studies and analyses upon Avhieh the i)j'esont .study and report are based. Scope of 1929 Investigation. The salinity investigation whieh was progranunetl and carried out during the .season of 1929 has been by far tlie most comi)rehensive and intAisiA'e in its scope of any of the preceding years' inA'cstiga- VARIATION AND CONTROL OF SALINITY 25 tions. The adopted program was designed with the purpose of obtain- ing all necessary information and data required for the completion of a study and analysis of the variation and control of salinity in the delta and upper hay channels. The seojie of the investigation is sho^^^l on Plate III, "Sacramento-San Joaquin Delta and Upper San Francisco Bay Region, Showing Main Features of Salinity Investiga- tions." The locations of all stations for regular salinity observations, special salinity surveys and stream gaging, and tide gages are shown on this plate. The field Avork and office studies were actually started in May, 1929. Seventy-six (76) regular salinit3^ observation stations were established and maintained throughout the season. Samples of the water at these stations were taken regularly at four day intervals about one and one-half hours after high tide and immediately below the water surface, designated as the surface zone. In practically all cases, local observers were appointed to take the actual samples which were mailed in special bottles and containers to the testing laboratory of the State Di^dsion of Highways in Sacramento, where they were analyzed. Observers were instructed to take samples if possible about one and one-half hours after high-high tide, but where impossible or impractical, they were instructed to take the samples at about one and one-half hours after low-high tide. Each observer was furnished with a schedule shoAA-ing the exact time at which samples were to be taken. The actual time of taking samples was reported by each observer on a tag on the sample bottle sent in. At 22 of these stations, samples were taken for both higli-high and low-higli tides during a period of four months, and at Antioch, samples for both low-high and high-high tides were taken throughout the season. During jieriods of variable stream flow into the delta such as occurred in June and again in December, 1929, daily samples were taken throughout the variable flow period at all stations which were affected by the changing flow conditions. In addition to regular salinity observation stations maintained at points in the bay and delta channels, sampling stations were estab- lished on six of the islands for the purpose of determining the salinity of the drainage water discharged from the islands during the season, as compared to the salinity of water in the adjacent channels. Samples were taken of this drainage water at seven stations at four day inter- vals, generally at the same time that the samjJes of the water in the adjacent channels were taken at the nearest stations. Two types of special salinity surveys were made, including "tidal cycle" and "river cross section" salinity surveys. The tidal cycle salinity surveys involved the taking of samples at hourly intervals over a tidal cycle period of about 25 hours, samples being taken at depth intervals of five to ten feet from the surface zone to the stream bed. These tidal cycle salinity surveys were made at several different stations selected in the delta and bay and scheduled to include all variations of salinity, tidal and channel conditions. Each survey included the taking and analysis of from 90 to 317 samples. In all, this type of survey was made at 14 different stations with 90 surveys completed. The purpose of these surveys was to determine the variation of salinity at different depths with the rise and fall of the tide. 26 DIVISION OF WATER RESOURCES The second type of special surveys, designated as "river cross section" salinity surveys, comprised the taking of samples at various intervals of width and depth throughout a complete channel cross section. Two channel cross sections were selected, one in the San Joaquin River opposite Antioch and one on the Sacramento River directly north of the section on the San Joaquin River, Samples were taken for the most part immediately after high-high tide, hut some surveys were taken immediately after low-low tide or other tidal phases. The purpose of these surveys was to determine the lateral variation of salinity through a channel cross section. About 70 samples were taken and analyzed for each survey. In all, 33 separate surveys of this type were made. A series of more intensive measurements also were carried out at these two river cross sections, which included the taking of water samples and coincident measurements of tidal velocity at hourly inter- vals throughout a complete tidal cycle period of about 25 hours and at depth intervals of from five to ten feet from surface to bottom, at each of three stations located at fixed points on each of these river sections. These were by far the most complete special salinity surveys attempted, the data obtained showing the related variation of tidal velocity and salinitj' throughout a complete tidal cycle for an entire river cross section. All water samples obtained at the regular salinity observation sta- tions and the special salinity surveys were analyzed at the State Division of Highwaj^'s testing laboratory in Sacramento. Samples were analyzed for chlorine content, salinity of the water, or degree of salinity, being expressed in number of parts (by weight) of chlorine per 100,000 parts (by volume). The method of analysis used by the State Chemist is known as the ]\Iohr method, which is tlie more usual standard for analysis of chlorine in water, being rapid and accurate. The method is a so-called ''titration" operation, making use of a silver nitrate solu- tion standardized with a known strength of sodium chloride solution, and a potassium chromate solution as an indicator. Silver nitrate of a known strength is added to a sample of the water, to which potassium chromate solution has been added previously, until the color of the chromate changes to a standard color indicating that the reaction is completed. The volume of silver nitrate added as related to the volume of the samjile then gives tlie number of parts of chlorine present. With an experienced chemist, the method is considered to be one of the most accurate of chemical determinations. A more detailed description of the methods used in tlie laboratory is included in Appendix B of this report. In addition to the chlorine determinations made on the standard samples, a series of complete chemical analyses of water sampled at dif- ferent points in the bay and delta channels during different times of the season were ma(*f'. These complete analyses included the determination of total solids, chlorides, sulphates, carbonates, bicarbonates, sodium, magnesium, lime, silica, iron and alumina and total hardness. The pur- ]iose of these comjileto chemical d(>terminations was to find out if possible the character and source of the salinity and hardness of the water. An important part of the 1929 field work on salinity investigations was the measurement of flow in the branch channels of the Sacramento PLATE III 26 DIVISION OP WATER RESOURCES The second type of special surveys, designa,ted as "river cross section" salinity surveys, comprised the taking of samples at various intervals of width and depth throughout a complete channel cross section. Two channel cross sections were selected, one in the San Joaquin River opposite Antioch and one on the Sacramento River directly north of the section on the San Joaquin River. Samples were taken for the most part immediately after high-high tide, but some surveys were taken immediately after low-low tide or other tidal phases. The purpose of these surveys was to determine the lateral variation of salinit}'^ through a channel cross section. About 70 samples were taken and analyzed for each survey. In all, 33 separate surveys j of this type were made. A series of more intensive measurements also were carried out at these two river cross sections, wliich included the taking of water samples and coincident measurements of tidal velocity at hourly inter- vals throughout a complete tidal cycle period of about 25 hours and at depth intervals of from five to ten feet from surface to bottom, at each of three stations located at fixed points on each of these river sections. These were by far the most complete special salinity surveys attempted, the data obtained showing the related variation of tidal velocity and salinity throughout a complete tidal cycle for an entire river cross section. All water samples obtained at the regular salinity observation sta- tions and the special salinity surveys were analyzed at the State Division of Highway's testing laboratory in Sacramento. Samples Avere analyzed for chlorine content, salinity of the M'ater, or degree of salinity, being expressed in number of parts (by weight) of clilorine per 100,000 parts (by volume). The method of analysis used by the State Chemist is known as the Mohr method, which is the more usual standard for analysis of chlorine in water, being rapid and accurate. The method is a so-called "titration" operation, making use of a silver nitrate solu- tion standardized with a known strength of sodium chloride solution, and a potassium cliromate solution as an indicator. Silver nitrate of a known strength is added to a sami)le of the water, to which potassium cliromate solution has been added previously, until the color of the chromate changes to a standard color indicating that the reaction is com])leted. The volume of silver nitrate added as related to the volume of the sample then gives the number of parts of chlorine present. With an experienced chemist, the method is considered to be one of the most accurate of chemical determinations. A more detailed description of the methods used in the laboratory is included in Appendix B of this report. In addition to the chlorine determinations made on the standard samples, a series of complete chemical analyses of water sampled at dif- ferent points in the bay and delta channels during difFei-ent times of the season were ma(*e. These complete analyses included the determination of total solids, chlorides, sulphates, carbonates, bicarbonates, sodium, magnesium, lime, silica, iron and alumina and total hardness. The pur- pose of these complete chemical determinations was to find out if possible the character and source of the salinity and hardness of the water. An important part of the 1929 field work on salinity investigations was the measurement of flow in the branch channels of the Sacramento '.K'JfLAR SAIJNITV STATIONS 1 Poim Orient 49n Jcmey Drain : Grand Vlew r.u Blylock Landing 3 LakevIHe 51 Tnrllchell lalund Pumii 1 Pei&IUTna 52 Wehb Point 5 Sonoma Creek Bridge es Central LondlnB. Bouldin IslutiJ SSa Central Landing, Alnln T Meraio 51 Camp S. Tj-ler island S CoiiliiBE %Thart 56 Cunip T. Stnten Island Tyler Island Furry H Bulls Heaa Point liO New H"pe Bridge CI Camp 20, Slaten Island cz Camp 24. Siat«n Island ns Camp 25, Staten Island 64 Camp 2». Stnten Island 1!. O ft A. Briape c& Camp 33. Staten Island SO CcmasvHh «6 Camp 16, StAten Island "1 Mayhem- (Prior to Cl 1929) e6a Cami> ih. Slaten laluud Drain 21 B May berry 67 Camp St. Kings Island 21 Emmalim liK Sing Kb* Landing :'S Three Mile Slough Bridg^^ 69 Webb Pump 2* Three Mile Slough Ferry 70 Blakes Landing, Vcnjc^ I-lnnd if Rio Vista BrWge 71 Quimby Pump ■6 Junction Polnl 72 Ward Landing ;T Byer Island Perrj- :a M Sla Grand Inland Df»1". Slenmbont Slough TOn Mnndevllle Drain S: Walker Landing TGb Bacon Island Dniln ■■■ Hr.wArd FtrT>- 71 Holliind Pump -i.ii.d Home :i Palm Tract ■.r Slough 79 Orwood Bridge 1 ri,. Holland Ferry BO Middle niviT. Poat OfllCe a: i»ifi..ii BruiB^ «0a Middle Rlvor. Main !» Rydt SI Es»t Contra Costa IrrlB.ni'in DlHrlcl SS Walnut Gr..\< 82 Mnnalon Mouse Ui Granil iKland Bridge 8S Zuckcrman Pump 84 WakcReia Landing 43 Hood Perr>' 86 Stockton Country Club )S Freeporl Fi-rry *« Stockton ( Sacrarni^nto ST Williams Brldgr s Verona SI Dresler 8 rid go A Aniioch 89 Clifton Court Fi-rry 7 Curlls Landing 90 \\Tiltehall S Sherman island Ferrj- HI Moudale, Highway Brldg^- 3 Jersey ■-•i Weslrrn Pacific Railroad Bridge Durham Forry Bridge s;kiiai, tidal cycle-depth salinity stations 1 Polni Orl^nl Aniloch : Crockett Aniloch BrldB- ; Bolls Head P-lnt Itio Vlata Bridge 1 Avon Sttcramvnio II Street Bridget 5 Bay Point Curtis Landing 6 NIcholls (Central Chemleni Co, Wharf) Central landing. Bouldin Iclnnd : Colllnsvllle Mosadale Highway Bridge .SI-ECIAL STREAM GAGING STATIONS 1 Sutt-rr aiougb 4 Georglana Slough • Sleatnbeal Slough Thrf-C Mile Slough 3 Sacramento River Below Georglana Sloueh TIDE GAGE STATIONS Presidio Hunt«rK Point Point BluB Oakland Mole Polnl Orient Pinole Point Beacon No. :; Sonoma Creek F'etaluma Creek Crockett Mare Island Benlcla Bay Point Sulsun Light Point Buckler Mallard Slough Melnn Landing Collinavllle Thrw Mile Slough, Sii'T.imr'iilo River nio Vlata Walnut Orovc Sacrarocntn Anilnoh Thrve Mile Slough, Sun Ji>a'quln Ftlvv Venice Island Georglana Slough Boat Contra Costa County Irr Dlnlrl' Ni^w Hope Bridge Stockton Moasdalt S, P. R R. Brldt^ -■ml : (irnij'l bnslRl II iftffT'^i )nl' ^^biiH ^J n i;i > I II-' iliT'-. , iiih • i J?; bnnfftl no)«i^ i>rtRfeI nsJjiiB ,tl qmsO . ■! r 9J3r.5r bnafsl ri bnalel n^»J*i)<'- ,* !i ymji') ' - 'I ntiBiB .*IS qin.. - nIaiCl bniiU hni. qmuH ddaV/ ,1 ^ qmW i : iflivohrtJil/l B'' .( Y/ ^t f>iv)!G ITOitBtSi Jfi, XT^'i^'i liKlKiunl ;i v,no'5 .A A .f) 81 (es«r .jy noJurnma jnio4 ft".'; ■nirl in: timioia iHiBti) IcI OnB'ji) $£ V alt ...,;>ii , •.,.■! oliJRia noUftslnl b! VARIATION AND CONTROL OF SALINITY 27 River below Sacramento, including the interconnecting channels between the Sacramento and the San Joaquin rivers, for the purpose of deter- mining the effect of the distribution of flow in these channels on the extent and degree of saline invasion in different parts of the delta. Measurements were made of the flow in Sutter, Steamboat, Georgiana and Three-Mile sloughs and of the Sacramento River below the upper mouth of Georgiana Slough immediately down stream from Walnut Grove. All measurements were made by current meter, with standard methods and equipment employed. Because of the fact that the rate of flow in these channels during the period of low stream flow is not uniform but varies with the rise and fall of the tide, each complete measurement comprised stream gagings at one-hour intervals through- out a complete tidal cycle period of about 25 hours. However, except for the multiplicity of gagings required, the measurements were of the usual standard type of stream gaging operations b}^ current meter. For the purpose of obtaining comprehensive data on tidal action in the bay and delta channels and determining the effect of tidal action on the variation of salinity, automatic tide gages were established at strategic points in the bay and delta channels. Ten automatic tide gages were already in operation at points in the delta, four by the U. S. Army Engineers, four by the State and two by private agencies. A tide gage was also in operation at the Mare Island Navy Yard and likewise the basic tide gage of San Francisco Bay, maintained by the U. S. Coast and Geodetic Survey at the Presidio near the Golden Gate. Six new tide gages were installed by the State in 1929 and fifteen by the State and U. S. Army Engineers in 1930. All of these tide gages were connected together by precise lines of levels to tie them in to the same datum. In making these level surveys, the U. S. Geological Sur- vey cooperated in running precise level lines from San Francisco to the upper bay region, thus for the first time accurately tying together the level datums from the lower end to the upper end of San Francisco Bay and the delta area. With this system of precise levels connecting all automatic tide gages, it was possible to reduce the tide gage records to the same datum and thus obtain the instantaneous relation of the elevation of the water at all points in the tidal basin. Measurements of stream flow into the delta from the Sacramento and San Joaquin rivers and their tributaries were continued during the 1929 season as in previous years to determine the source and amount of daily inflow into the delta. Gaging stations were maintained at points on or near the rim of the delta for all streams. The comprehensive experiments on consumptive use of water in the delta, which have been in progress in cooperation between the State and the U. S. Department of Agriculture since 1924, were virtually brought to completion. These experimental measurements have been directed to a determination of the consumptive use of water for all of the important crops grown in the delta and also for natural vegetation and evaporation. In order to obtain data on consumptive use, it was found necessary to measure the water used by means of tanks specially constructed for the purpose. The details of these several years of experiments are described in another report * and mil be further amplified in subsequent reports. * Bulletin No. 23, Report of Sacramento-San Joaquin Water Supervisor for the period 1924-1928, Division of Water Resources, 1930. 28 DIVISION OP WATER RESOURCES Duriiij.'T 1929 from May until the end of the year, over 20,000 Avater samples were taken and analyzed for salinity. ()£ these about 5000 samples were taken and analyzed from the regular salinity observiition stations and over 15,000 for the special salinity surveys. The compila- tion and analysis of the larjje amount of data jrathered durinj]: 1929 and in previous years have presented a task of no small magnitude. Inas- much as the study of this salinity problem has involved a field of research in which little if any investigations have ])reviously been made that would assist in the present investigation, the studies liave often required a multii)licity of trial analyses before the final procedure as to proper method of analysis was determined. The results of the investigation of the variation and control of salinity in the Sacramento-San Joaquin Delta and upper San Francisco Bay are briefly summarized in the remaining portion of this Chapter. The detailed presentation of the studies and analyses with graphs and tables in Chapters II to V, inclusive, is essential to a full understanding of the basic relations and conclusions derived from the investigation, and should be consulted for complete information. Salinity Conditions. Although actual records of salinity in the upper bay and delta channels are of rather recent date, there is considerable general his- torical information as to salinity conditions. As early as 1775, a Spanish expedition under command of Don Juan oManuel de Aj'ola reported saline water in the upper part of Suisun Bay in the summer of that year. In the sunnner of 1841, the expedition under Commander Ring- gold reported the presence of saline water in the San Joaquin River near Antioch. The early settlers on the Suisun Bay marshlands were familiar with the fact that saline water invaded Suisun Bay each year, usually to the upper end thereof. Several of the early residents of the town of Antioch have stated that saline water invaded the lower channels of the delta during many years, as early as the sixties and seventies, to such a degree that the water at Antioch was uns'uitable for domestic consump- tion. A more recent source of information as to salinity conditions is available from the records of water barge travel of the California- Hawaiian Suu:ar Refining Corporation. This company, whose plant is located at Crockett, has obtained mo.st of its fresh-water supply from 1908 up to the ]n'esent time (1981) by hauling the same in barges which were filled at points u))stream where fresh water was found. The record of the distance traveled above Crockett thus furnishes information as to the dividing line between saline and fresh water throughout this period. The record shows that saline water extended into the lower channels of the delta in varying degree during a period of three to nine months in most every yeai- fi'om 1908 to 1920. Based upon this historical informa- tion, it is evident that the invasion of saline water into Suisun Bay with some salinity reaching as far upstream as the lower end of the delta is a natural phenomenon which occurred i)rior to the time of extensive develo])ments of reclamation, irrigation, and storage works on and bordering the Sacramento and San Joaquin rivers. The salinity conditions in the upiier bay and delta channels during any season are characterized by mai-ked cyclic variations. The maxi- mum retreat of salinity and the farthest downstream advance of fresh VARIATION AND CONTROL OF SALINITY 29 water oecurs during tlie flood season of winter and spring. As the stream flow gradually decreases with the approach of summer, saline water gradually advances upstream until the maximum extent of advance and degree of salinity is reached in late summer. After the maximum salinity for the .season is reached, it gradually decreases at all points and retreats downstream until it again reaches a point of maxi- mum retreat during the following flood season of winter and spring. Based on the records from 1920 to 1929, saline water generally starts to advance into the channels at the lower end of the delta in the latter part of June, but varying from early May to the latter part of July. The period of saline invasion into the delta channels generally extends from this time until November or December, when the first wnnter freshets of magnitude occur. During the remaining portion of the vear, the water in the entire delta is fre.sh. Saline water advances into Suisun Bay at a much earlier date and remains during a longer portion of the year. However, in many years, the water of Suisun Bay becomes entirely fresh for a certain period during the winter and spring months. In some years of heavy floods, fresh water extends down into San Pablo Bay for limited intervals of time. In most every year, the .salinity of Avater in Suisun and San Pablo bays is greatly reduced during the winter and spring season. However, under present condi- tions, during the greater portion of each year, the water of San Pablo Bay has a saline content approaching that of ocean water, Avhile the water in most of Suisun Bay reaches a salinity usually averaging 50 per cent or more of that contained in ocean water. The salinity conditions in the tidal channels of the Napa Kiver and Sui.sun and Petaluma creeks are quite similar to those in the channels of upper Suisun Bay and the lower delta. The same type of cyclic variations of salinity occur, characterized by the advance of salinity upstream in the channels starting in the late spring and extend- ing throughout the summer and fall months, and the retreat of salinity downstream with the saline water replaced by fresh water during the winter and. spring months. During certain years of the thirteen-year period, 1917 to 1929, the extent of saline invasion into the Sacramento-San Joaquin Delta has been greater than ever before known to have occurred. In 1924, the waters in the channels of about 50 per cent of the delta area had a salinity content, at the time of maximum extent of invasion, in excess of 100 parts of chlorine per 100,000 parts of water (based upon samples taken in the surface zone usually after high-high tide), or a greater salinity than has been a.ssumed suitable for irrigation use in the delta. In 1920 and 1926, about one-fifth of the delta was similarly affected. In the remaining years of this period, the extent of invasion was not serious, only 3 to 9 per cent of the delta area being similarly affected.* * Since the preparation of this report, the extremely dry season of 1930-31 has occurred, which resulted in an unprecedented saline invasion into the delta. At the time of its maximum extent, about 70 per cent of the delta had salinity in excess of 100 parts of chlorine per 100,000 parts of water. Tlie saline invasion started into the delta in early April and gradually advanced upstream as far as Courtland on the Sacramento River, above Stockton on the San Joaquin River, above Williams Bridge on Middle River and above Clifton Court Ferry on Old River. The detailed records of salinity for 1931 are tabulated in Appendix C. The saline invasion in 1931 has been far more serious in its magnitude and affect than in any previous year of record. Irrigation diversions were curtailed on a much larger area of delta and for a much lonarer period of time than in any previous year. The extent of invasion in 1931 is shown on Plate LXXXII. 30 DIVISION OF WATER RESOURCES Based upon records obtained on six typical islands in the delta durinji; 1929, it a])pears in ^'eneral that tlie salinity of drainage water pumped from the islands averages about the same amount as the salinity of water in the adjacent channels during the irrigation season, but becomes somewhat greater on some of the islands during the winter and spring months, in the lower delta where the channels are usually invaded annually with saline water to such an extent that irrigation diversions are discontinued, the salinity of drainage water appears to remain about the same throughout the period of saline invasion as the amount present at the time irrigation diversions ceased, and is apparently unaffected by the presence of large amounts of salinity in the adjacent channels surrounding the islands. The period of invasion of salinity of high degree does not api)ear to have been long enough, up to 1930, to have caused an increase of salinity in the interior ground water. Basic Factors Governing Salinity Conditions. The basic factors governing the extent of saline invasion and retreat and the rate of advance and retreat of salinit}^ are stream flow into the delta and tidal action. The effect of stream flow into the delta is modified by the consumption of water in the delta by crops, vegetation and evaporation. The variation of salinity is the direct result of the relative magnitude of the opposing forces of tidal action and stream flow. Stream Flow — There are wide variations in the stream flow into the delta as to total amount from season to season, and as to the flow from month to month and day to day in any particular season and for different seasons. The total seasonal stream flow into the delta from the combined Sacramento and San Joaquin River systems averages a little over 31,000,000 acre-feet for the 58-year period, 1871 to 1929, inclusive, and practically the same amount for the forty-year period, 1889 to 1929, inclusive. The corresponding averages for the twenty, ten and five-year periods, to and including 1929 are considerably less, being about 24,000,000 acre-feet for the twentj'-year period and about 19,000,000 acre-feet for the ten and five-year periods. The total sea- sonal stream flow into the delta has varied from a minimum of 18 per cent to a maximum of 2G1 per cent of the 58-yoar mean. Prior to 1917 there was a preponderance of wet years with more than average total seasonal stream flow. Since 1917, however, there has been a preponderance of dry years of less than average total seasonal stream flow. This period includes the driest season of record up to 1930, namely, 1923-24, when the total seasonal flow into the delta .was but 18 per cent of the 58-year mean. During the twelve-year period, 1917 to 1929, inclusive, there haA^e been but two seasons of normal stream flow, and, of the balance, there were five seasons with a total seasonal stream flow into the delta of 50 per cent or less of the 58-year mean. Most of the stream flow occurs during the period January to June, in the winter and spring months, during which over 80 per cent of the total seasonal stream flow occurs on the average. During the five or six summer and fall months, only 10 to 20 per cent of the total VARIATION AND CONTROL OF SALINITY 31 seasonal stream flow occurs. Thus, the available stream flow into the delta is a minimum during the period when consumption of water in the delta is a maximum. The variations in daily stream flow into the delta are even more marked. During the period 1919 to 1929, the combined flow of the Sacramento and San Joaquin rivers into the delta has varied from a minimum of about 700 second-feet in August, 1920, to a maximum of 353,000 second-feet in March, 1928. As far as known, this minimum combined flow in August, 1920, is the smallest amount that has ever occurred up to 1930.* It was supplied about equally from the Sacramento and San Joaquin rivers. On the other hand, the maximum daily stream flow into the delta probably has been greater in past years and it is estimated that it might reach a rate of between 700,000 and 800,000 second-feet under future maximum flood conditions. The greater portion of the stream flow into the delta usually comes from the Sacramento River. Hence, under present con- ditions, the delta is dependent to large extent on the Sacramento River for its irrigation supply. The stream flow into the delta has been considerably modified, especially in recent years, by irrigation and storage developments on the Sacramento and San Joaquin River systems above the delta. The direct diversions by upstream irrigation developments have resulted in reducing the flow into the delta during the irrigation season. Where storage developments have been made for irrigation purposes, the regimen of stream flow has been modified by their operation in other months of the year as well as the irrigation season. In addition, the operation of storage reservoirs constructed for hydroelectric develop- ments have considerably modified the regimen of stream flow into the delta, although usually in themselves resulting in no material reduction in total flow. Up to the present time, irrigation has had by far the greatest effect upon the inflow^ into the delta. From 1910 to 1929, the area irrigated from the combined river systems increased at the rate of over 36,000 acres annually, reaching a total of about 1,317,000 acres in 1929. The growth during the five-year period, 1915 to 1920, was much more rapid, amounting to about 67,000 acres annually, chiefly as a reflection of the development of rice culture in the Sacramento Valley. From 1910 to 1929, the gross annual irrigation diversions increased from less than 3,000,000 to over 5,000,000 acre-feet with an increase of over 1,000,000 acre-feet in the five-year period from 1915 to 1920. These irrigation diversions are chiefly in the period April to October and reach a maximum rate in midsummer when, at the same time, the stream flow naturally available is a minimum. Not all of the water diverted for irrigation is actually consumed by the crops and it is estimated that 35 to 40 per cent or more of the gross diversions is returned to the streams below the irrigated area. However, the return flow is delayed and it is estimated that 75 per cent or less of the total return flow actually becomes available during the irrigation season. •Since the preparation of this report, the extremely dry season of 1930-31 has occurred, resulting in an unprecedented minimum flow into the delta of less than 500 second-feet from the combined river systems. During a period of about two weeks, there was practically no inflow into the delta from the Sacramento River passing Sac- ramento, and the only water coming into the delta during this time was return flow from the San Joaquin River and water released from reservoirs on the Mokelumne River. 32 DIVISION OF WATER RESOURCES iStorago developments on the Sacramento ai^d San Joaquin River systems have increased from about 350,000 acre-feet total capacity in iniO to over 4,000,000 acre-feet in 1929. Nearly 3,000,000 acre-feet of this total has come into operation since 1020. Most of tlie water released from storaj-e, whether pi-imarily for power or irrigation, is used for irrigation during the irrigation season before reaching the delta. Based xipun a study of the combined effect of irrigation diversions and storage operations, taking into account tlie amount of return water from irrigation, and the period, amount and use of reservoir releases, it is estimated that the stream flow into the delta has been substantially reduced below that which would have naturally occurred in most' months of the 3'ear, with the possible exception of some of the late fall or early winter months. In this latter period, in some years, the amount of return flow combined with power releases appear to have resulted in actually increasing the flow above that which would have naturally occurred. The reduction of stream flow into the delta, especially during late spring and summer, resulting from these upstream developments, has had a substantial effect in decreasing the force exerted by stream flow against saline invasion, as compared to that which would have prevailed under conditions of natural stream flow before the large increases in diversions and storage of the last 10 or 15 years. This large increase in ii-rigalion and storage developments has been coincident Avith a period of .subnornud precii)itation and nat- urally reduced stream flow, and hence, in the drier years, its propor- tional efiFect on the extent and degree of saline invasion has been large. Consumptive Use of Water in Delta — Based upon observations and experiments for six years as described in Chapter II, the present con- sumptive use of Avater in the delta by crops, vegetation and evapora- tion is estimated to vary from a minimum of about 800 acre-feet per day or 400 second-feet (in midwinter) to a maximum of about 7400 acre-feet per day or 3700 second-feet at the peak of the irrigation season (in midsummer). The estimated total annual consumption on the gross area of the delta of about 488,000 acres amounts to 2.6 acre-feet per acre. The estimated total seasonal consumption on 321,800 acres of irrigated crops alone amounts to 2.1 acre-feet per acre. During several years in the period 1920 to 1929, the inflow into the delta during the summer months has been insufficient to take care of the consumptive requirements. The shortages in supply occurred during periods of one to three months in five years out of ten. These same years have also witnessed the invasions of salinity of greatest degree and extent. Tidal Action — Tidal action in any tidal basin is evidenced by the .rise and fall of the water level and the tidal currents induced by the move- ment of water into and out of the basin. On the Pacific Coast the tide generally rises and falls twice during a lunar day of 24 to 25 hours, resulting in the occun-ence of two his'h and two low phases of water level. Tlu' level actually reached by the high and low tidal phases varies considerably from day to day, and on the same day as well. There are generally tAvo hi<,di phases of the tide each day, designated as high-high and low-high tide, and two low phases designated as low- low and high-low tide. Tlu' difference in level or tlie range of the tide between the successive phases thereof varies widely as between different VARIATION AND CONTROL OF SALINITY 33 phases on the same day and as between the same successive phases on different days. The mean, average, and maximum ranges of the tide are generallj^ greatest at the lower end of the bay near the Golden Gate, and gradually decrease to minimum amounts at the upstream limits of tidal action in the basin. There is also considerable variation in the average water level or mean tide from day to day during the year and for different years. The tidal basin of San Francisco Bay has a total area at mean water surface level of about 500 square miles, with a total volume between the limits of maximum tidal range of about 3,000,000 acre-feet. The volume of that portion of the tidal basin in the Sacramento- San Joaquin Delta between the maximum limits of tidal range amounts only to about 250,000 acre-feet, or about 8 per cent of the total tidal basin volume. The water level in the tidal basin is never a con- tinuous plane surface at the same instant, because of the fact that the time of occurrence of identical tidal phases comes at an increasingly later time after their occurrence at the Golden Gate, the farther upstream in the basin. Identical tidal phases occur at upstream points as much as ten hours later than at the Golden Gate. Since successive tidal phases occur on the average about six hours apart, it may be readily seen that the tide may be rising in the lower part of the basin at the same time that it is dropping in the upper part of the basin and vice versa. The actual tidal flow into and out of the tidal basin, or any portion thereof, is therefore considerably less than the total poten- tial volume in the tidal basin, included within either the maximum or average limits of tidal range. The volume of the actual tidal prism between the limits of water surfaces at time of slack water following any two successive phases of the tide at the mouth of the basin is the chief measure of the amount of tidal flow into or out of the basin between these two successive tidal phases. However, the exact measure of tidal flow must be based not only upon the tidal prism volume, but also upon the additions by stream flow and the extractions by con- sumption into and out of the basin respectively. When the tide rises in what is termed the flood period, stream flow into the basin tends to decrease the magnitude of tidal flow into the basin, whereas consump- tion of water tends to increase the same. When the tide falls during what is termed the ebb period, stream flow tends to increase the tidal flow out of the basin, whereas consumption tends to decrease the same. Thus, if the consumption in a tidal basin above any point exceeds the stream inflow at any time, it is evident that the tidal flow into the basin will tend to exceed the tidal flow out of the basin, even though the tidal prism volume be the same in ebb and flood. On the other hand, during the occurrence of floods of large magnitude, it is apparent that the stream flow into a tidal basin above any point might be suf- ficient to eliminate entirel}'^ the tidal flow into a basin, thus resulting in a continuous ebb flow. The amount of tidal flow past any section in the tidal basin is chiefly dependent upon the volume of the tidal prism in the basin above the section, and therefore increases for sections further down- stream. During the months of low stream flow, the total amount of tidal flow during a lunar day into and out of the delta tidal basin 3—80995 34 DIVISION OF WATER RESOURCES averages about 350,000 acre-feet and, into and out' of the tidal basin of Suisun Bay and the delta combined, about 600,000 ficre-feet. Of the total tidal flow into and out of the delta, about two-thirds results from that portion of tlie tidal basin comprising the channels of the San Joa- quin Hirer and its tributaries. The tidal flow into the upper portion of the San Francisco Bay tidal basin comprising Suisun Bay and the delta has been modified in ])ast years by various changes and developments resulting from recla- mation, flood control and navigation works ; and also from the effects of the movement and deposition of silt and water-borne debris emanat- ing from natural erosion and from hydraulic-mining operations. As far as deposition of debris from hydraulic mining and natural erosion is concerned in the tidal channels of the delta, the effect on tidal flow was temporary and has been mostly removed as a result of natural erosion and dredging operations for reclamation and navigation improvements. ' The reclamation of the lands in the delta has removed a portion of the original potential tidal volume within the delta tidal basin. However, because of the rank vegetation growing under natural con- ditions on the delta lands, and the different rate and character of tidal movement than at present, this larger tidal volume in the delta under natural conditions probably did not result in a much larger tidal flow than at present into and out of the basin. Tt is probable, however, that the reclamation of lands in the delta has had the effect of decreas- ing to some extent the tidal flow into and out of the basin past points at or near the lower end of the delta. Similarly, the reclamation of the marshlands lying north of and adjacent to Suisun Bay has had the effect of decreasing to some extent the tidal flow into and out of the basin past the lower end of Suisun Bay and points downstream. The reduction in tidal flow and the decrease in the consumption of water in the delta by the elimination of considerable areas of aquatic vegeta- tion originally present, have tended to reduce the degree and extent of saline invasion which would have occurred in recent years had these lands not been reclaimed. However, since these changes occurred prior to 1920, they have had no direct effect upon variations in salinity during the period 1920 to 1929. The changes in the tidal basin that have modified tidal flow and hence have directly affected salinity conditions since 1920, include the widening and deepening of Sacramento River from Collinsville to a point above Rio Vista as a part of the Sacramento Flood Control Project, the flooding of the lower end of Sherman Island which accom- panied this channel enlargement, and the flooding of a previously reclaimed area lying south of the San Joaquin River and Dutch Slough. It is estimated that the Sacramento River channel enlargement has resulted in an increase of tidal flow into and out of the delta tidal basin of about 30,000 acre-feet per lunar day, and that the flooding of the previously reclaimed lands has resulted in an increase of tidal flow of about equal magnitude. These changes in amount of tidal flow have had an eft'ect on the extent and rate of advance and retreat of salinity during the last decade. / VARIATION AND CONTROL OF SALINITY 35 ation of Stream Flow Into Delta to Salinity. ^ The stream flow into the Sacramento-San Joaquin Delta is one ^^ the most important factors governing the advance and retreat of i'6/linity in the upper hay and delta channels. The force exerted by . Lream flow opposes the action of the tides in their tendency to push hyaline water upstream. Hence, the variations in amount of seasonal mream flow and of monthly and daily stream flow into the delta during %ny season are directly reflected in the total extent and rate of advance land retreat of salinity in the channels of the upper bay and delta. f The extent of advance and retreat of salinity are approximately I related to the total seasonal stream flow into the delta. In general, the I records show that the drier the season and the smaller the total seasonal stream flow entering the delta, the greater will be the extent of saline invasion during the summer and the smaller will be the extent of retreat of salinity in the winter and spring. However, the degree and extent of saline invasion in the summer season is more particularly governed by the amount and variation of stream flow into the delta during the summer months. The records show that the smaller the total amount of stream flow into the delta during the summer period of June 15 to September 1, the farther upstream will be the advance and the greater will be the degree of salinity reached at points in the upper bay and delta channels. During the period 1920 to 1929, there were no invasions of salinity of material extent into the delta when the summer stream flow from June 15 to September 1 averaged about 5000 second-feet or more. The actual occurrence of advance or retreat of salinity in any channel section of the upper bay or delta depends directly upon the rate of stream flow" passing the section and the degree of salinity present in the particular channel section at any particular time. This governing flow at any particular section is the net stream flow resulting from the flow into the delta reduced by the actual consumption of water in the basin above the particular section. For any particular degree of salinity at any particular point or channel section, there is a rate of stream flow which will equalize the action of the tides and prevent an advance of salinity. If at any time the rate of flow is less than the required amount to prevent advance of a particular degree of salinity, the salinity will tend to advance to points farther upstream and to increase to greater degrees at the particular point or channel section. If, on the other hand, the rate of flow is greater than that preventing advance, the salinity will tend to retreat to points downstream and to decrease to smaller degrees at the particular point or channel section. At any particular section, the rate of stream flow required to prevent advance of salinity increases as the degree of salinity at the particular point or channel section decreases. For any particular degree of salinity, the rate of flow required to prevent the advance of salinity becomes smaller the farther upstream the point or channel section. The maximum extent and rate of advance of salinity and the maxi- mum degrees of salinity which are reached in any season at various points in the upper bay and delta channels are directly related to the amount and variation in rate of flow into the delta and the amount and 36 DIVISION OF WATER RESOURCES variation of consumptive use of water by crops, natural vegetatio, ^ evaporation in the basin above the various points. In order to pi,^ advance of salinity at any point in the upper bay and delta cha. the rate of inflow into the delta must exceed the amount of wate' sumed above the i)articular point by an amount sufficient to eq the action of tlie tide in its tendency to advance salinity upstream, records show that, in 1921, 1922, 1923, 1925 and 1927 when the st ; flow into the delta during the summer months was sufficient to ., the consumptive demands in the delta, saline invasion into the delta g of small extent and degree, afl'ecting only about 3 per cent of the d» v area even at the time of maximum extent of invasion during the seas Saline water did not start to advance into the delta until about mid-Jm On the other hand, in years when the stream flow into the delta duriii^ the summer months w^as insufficient to meet the consumptive demand? in the delta, invasions of saline water of considerable extent and degr( have occurred. This was especially true in the dry years of 1924, 192- and 1926, when the stream flow was insufficient to meet the consumptiv demands for a considerable period of time. The records show tha salinity at points in the upper bay and delta channels continues to increase after the invasion has started until the stream flow into the delta increases to an amount sufficient not only to meet the consumptive demands, but also an excess amount sufficient to counteract the force exerted by the tides toward pushing saline water upstream, with the particular degree of salinity reached at the particular time. The rate of flow into the delta at the time of occurrence of maximum salinit}^ for the season is closely related to the maximum degree of salinity reached at typical points in the upper bay and lower delta channels. This relation shows that, at any particular point, the smaller the degree of maximum seasonal salinity reached the greater is the rate of flow into the delta at the time of occurrence of maximum salinity for the season. Thus, at Antioch, the data show that the rate of flow into the delta which prevented salinity from increasing above a mean degree (mean tidal cycle surface zone salinity), in parts of chlorine per 100,000 parts of water, of about 800 was about 3200 second-feet; of 200 parts, about 5400 second-feet, and of 100 parts about 6700 second-feet. Therefore, as an approximation, it is evident that with these flows main- tained into the delta, the mean tidal cycle surface zone salinity at Antioch would not increase above those stated above for the respec- tive flows. The relation is approximate, however, and applies only to a particular time during the season, averaging about September 1, when the maximum seasonal salinity usually is reached. Since the actual time of occurrence of maximum salinity in different years has varied from August 15 to September 15, at various points, the element of varying consumption in the delta affects the accuracy of the relation. It is evident that, at other times of the season when the consumption in the delta is different than the consumption at the time of occurrence of maximum salinity averaging about September 1, the flow into the delta related to a maximum salinity of any degree would differ by the amount of difference in the consumption on the two different dates. Therefore, the stream flow related to maximum salinity for an average time of about September 1 would have to be modified, with a correction based upon the diff'erence in amount of consumption, if the relation were ( VARIATION AND CONTROL OF SALINITY 37 applied to any other time of the year. The relation also takes no account of possible differences in magnitude of tidal flow at the time of occur- rence of maximum salinity in different years, which might affect the relation to some extent. It has been pointed out previously that the greater portion of the stream flow into the delta comes from the Sacramento River. In certain periods when there is very little inflow from the San Joaquin River sys- tem, the portion of the delta embracing the San Joaquin River and its tributaries is largely dependent for its consumptive requirements on supplies from the Sacramento River. This supply from the Sacramento River to the San Joaquin Delta is limited to the flow which passes through two sloughs ; namely, Georgiana and Three Mile Sloughs. Detailed measurements of the division of flow of the Sacramento River in the branch channels below Sacramento show that the flow through Georgiana Slough is directly related to the flow passing Sacramento, whereas the flow through Three Mile Slough bears no relation to the flow passing Sacramento, but results entirely from tidal movement, at least during the period of low stream flow. The percentage of the total flow passing Sacramento which goes through Georgiana Slough varies considerably with the rate of flow in the Sacramento River, varying from a maximum of about 43| per cent with a flow" of 3000 second-feet to a minimum of about 15 per cent for a flow of 40,000 second-feet or greater. The tidal flow through Three Mile Slough results in a net transfer from the Sacramento to the San Joaquin River of about 950 second-feet averaged over a period of about three months, but with extreme variations as measured from no flow to 3700 second-feet. If the entire consumptive requirements of the delta were required to be furnished from the Sacramento River, a supply of 3700 second-feet passing Sacramento, or the amount required at the time of maximum consumptive demands in the delta, would be distributed through the present connecting channels in about the same proportion as the respec- tive consumptive demands in the Sacramento and San Joaquin deltas. However, with a flow of 7000 second-feet passing Sacramento, or a suffi- cient supply to meet the maximum consumptive demands in the delta and also the net flow required to control salinity at the lower end of the delta, the division of flow would not be in proportion to these combined requirements of consumptive demand and repulsion of saline invasion in the two deltas. The portion flowing into the San Joaquin Delta through the present connecting channels would not be sufficient for the combined needs of the San Joaquin Delta. The effect of the proportional distribution of the Sacramento River flow, when there is very little inflow from the San Joaquin River system, is clearly evidenced in the records of salinity during the period 1920 to 1929. The extent of saline invasion has been proportionately greater in the San Joaquin Delta than in the Sacramento Delta. Moreover, salinity tends to remain in the San Joaquin Delta for a considerable period after increased stream flow in the Sacramento River has almost entirely removed salinity from the Sacramento Delta channels. Hence, if, under future conditions, the water requirements for consumption and repulsion of salinity must be furnished almost entirely from the Sacramento River, the present limited channel capacity connecting the Sacramento River with the San Joaquin Delta would not be sufficient to provide the 38 DIVISION OF WATER RESOURCES necessary flexibility in distribution and permit tli saline content of the water obtained. A map is also shown giving the distances in miles along the line of travel. Beginning in 1920 and up to 1929 the company obtained part of its supply from Marin County, and the broken record on the graph during these last 10 years shows the periods during Avhich water was obtained from this source. These records are of particular interest for the period prior to 1920, when few actual records of salinity are available. As shown on the graph, the distance traveled to obtain water of the purity desired varies from month to month each year, and differs considerably for the same month of different years, thus directly reflecting the changing salinity conditions and the periods of invasion and retreat of salinity. During the lO-j^ear period sfai'ting with 1908, the maximum average monthly distance traveled varied from 24 to 28 miles. In each of these years, it was necessary during a ]Kn-iod of three to six months to go 20 miles or more. By referring to the map, it is seen that water was obtained for considerable periods of time each year in the vicinity of Antioch and Collinsville or near tlie confluence of the rivers. Maxi- mum distances traveled during these years varied from 28 to 39 miles or well above Antioch. In the dry years of 1918 and 1919, the maxi- mum average monthly distance traveled was 38 miles and the maximum 65 miles. For a period of nine months in 1919 and early 1920, barges traveled to a point beyond the mouth of the rivers to get fresh water. It is evident, therefore, that from 1908 to 1920, there have been periods of from three to nine months during each year when all of Suisun Bay up to the lower end of the delta was impregnated by saline water in varying degrees, and that for shorter periods in each year, PLATE IV r'T'l'M" o E I " I " I 1 1 1 1 1 1 < 1 1 I 1 1 1 1 N I I rjlTj "i"i"i"i"i"i"|iir'i"i"i"l"i"n Barge travel up San Joaquin river TTTTTTTrTTT TfTTJTrjT V^-"^ n |i I M nrr 15 V L_ a. ni Q-O 5 e O ■- O '^ rn h i"ini"r'i"iiii"ri'Mii| 'i"i"i"i"i"i"i"|''i"i"i'T'i"i"'"r''"' Dates on diagram indicate the period that water was obtained from the Marin Municipal Water District 'i"i"i' 'I'TTT'I"!"!- ^ ^ o s. -h o ^o LEGEND Minimum barge travel Mean •• " — Maximum ■• •• BARGE TRAVEL OF CALIFORNIA & HAWAIIAN SUGAR REFINING CORPORATION 1908 TO 1929 3A 0£ 01 ■X- u o 3 o 3 o ff c -CO ^ inn f> 4^ '00 ^ 10 i " ° CO ■" ^-, "" iJ4^ c in fO 3 50 aJ o Delta ^ -c JL c s:J5? " -^::v. f_^ )CT. NOV. DEC. ■ " 100 80 60 90 70 0) «-' rt) (S> c ii ;o o O 100 80 60 40 E o >♦- (/) E c o c to 80 Q 60 AO STREAM FLOW INtO DELTA OF SACRAMENTO AND SAN JOAQUIN RIVERS AND RELATIVE VARIATION Of SALINITY IN BAY AND DELTA REGIONS 1919-1924 52 DIVISION OF WATER RESOURCES points on the same dates would be less. The relation of these observed values of salinity to the average or mean salinity on the same days and also the relation to the salinity at the low staples of the tide is pre- sented and disenssed in detail in Chapter IV. These records of salinity taken at the regular observation stations comprise the basic information on the variation of salinity in the bay and delta channels for the period of record. They are graphically presented on the u])per diagrams of Plate V, "Streamflow into Delta of Sacramento and San Joaquin Rivers and Relative Variation of Salinity in Bay and Delta Regions, 1919-1924," and Plate VI, "Streamflow into Delta of Sacramento and San Joaquin Rivers and Relative Variation of Salinity in Ba.y and Delta Regions, 1925-1929." These graphs are prepared in such a way that they not only show the variation of salinity from time to time at any point in the upper bay and delta covered by the actual records, but also the relative salinity at different points in the baj^ and delta at any particular time. The lines on these graphs indicate values of equal salinity in the surface zone after high tide expressed in parts of chlorine per 100,000 parts of water. The abscissa represent time divided into months, days and years. The ordinates represent distance from the Golden Gate measured from the bottom of each graph towards the upper edge of the plate. On the ordinates are shown the location of each of the more important key salinity observation stations. The actual salinity records for each station have been plotted on the horizontal lines repre- senting the location of each station, each recorded salinity being plotted for the day on which it was taken. With these points as a basis, lines of equal salinity were drawn on the graph. The points of intersection of these lines of equal salinity with a horizontal line drawn through the graph, therefore, indicate the variation of the salinity at a point in the basin from day to day through the season. The points of intersec- tion of these lines of equal salinity with a vertical line on the graph indicate the variation of salinity at any particular time at different points in the basin. Thus, for the year 1924 at 0. and A. ferry, the graph shows a salinity of about 350 on June 1st, 750 on July 1st, 1100 on August 1st, 1300 on September 1st, 1150 on October 1st, 700 on November 1st and about 100 on November 20th, all in parts of chlorine per 100,000 parts of water. On September 1, 1924, the salinity at 0. and A. ferry was about 1300, at Collinsville 1100, at Emniaton 800, at Three Mile Slough 700, at Rio Vista 450, at Isleton 50 and at Walnut Grove 10, all in parts of chlorine per 100,000 parts of water. Separate graphs are shown of the variation of salinity along the Sacramento River, San Joaquin River, Mokelumne River and Old and Middle rivers. These separate graphs are necessary because of the marked difference in variation along these separate geographical sec- tions of the delta. The variation of salinity for stations in the bay region are shown combined with the diagram of salinity variation along the Sacramento River section. Inasmuch as the salinity observa- tions at stations in the bay region below the delta were not started until 1926, no graphical records of salinity in the bay region are shown prior to that year. A study of the graphical and tabular records of salinity during the last decade shows that there has been an invasion of saline water into Dreilef Bfrf?e,_ClrflcKi' ■ ■■ A«eti Pump . ttollBtia Pump-' OLD AND MIDOIC RIVERS SECTION 18 — Camp V. Southnvett fv^\ Central Li aiLanttnU.-l i . I . ) I j .,. I ■ I ! ■ \ ■< A A ■ ■■! ■ -^-^ MOKELUMNE IVEFI SECTION UcsstJaieKi^nwayBrlifff - - stockwcc 1'«; . _ MtDonaldPump-.^™; ttftt. _, w^-PBmfersvilleBr™ ! j:. , , __ , ' "j'l , BAV AND SACaAMENTO RrV£R SECTION ■ - Stoekton C C --MtOofiaid Pump - - Blakes Landing "Ceniral Landing Jersey ° Anlioch _ftiniersifllle 8nc -Suner Slough - -fiioVlsra Br Emmaton Siochion"'' " " fiindge Pomp-- Wards Landinji'- WebbPumo " Twncrielllsiand-- CuTTis Landing-- Walnul Grove Islet on Bridge — Three Mile Slough "" Coiiinsville — '%. w 1 - Tcxr 1 f--:4- 1 -■^■f" -'T «».»[ 11 r? 9^i^ fefevi ] 1 1 1 r 1 ,, .... -- — uu - -- '■I'Jrt; ' T ~'^, 'o^^^ \it^^ -WNieMi! -- V..wii,ams Bn"d^ „ ■Clllwi Coun ftrryzDr e.ter Sndge ■ECCID -i^ans«n House ~i iTlandeville Pump - Orwood errdCe — \ Bl «oll«nd Pump -- Webb Pump BAT AND SACn^EKTO RIVER SECTION STREAM aOW DELTA or SACRAMENTO im SAN JOAOU^N RVtBS RELATIVE VARIATION OF SALINITY IN BAY AND DELTA RECIONS /^ r\ /~^ VARIATION AND CONTROL OF SALINITY 53 the delta each year during the period, but with a considerable variation from year to year as to its degree and extent. The invasion of saline water into the delta, as evidenced by the record at Collinsville, has started from as earty as May in 1924 to as late as July 23, in 1923.* After the invasion has started, the salinity usually continues to advance upstream into the delta for a period of about two months, generally reaching its maximum limit of invasion and maximum salinities at various points in the delta channels about the first of September, but varying anywhere from about mid-August to mid-September. After reaching the stage of maximum advance the salinitj^ starts to slowly retreat from the delta channels. This retreat usually continues more or less steadily with the salinity gradually decreasing at all points until about the middle of November to the latter part of December, when the waters in the delta channels down to the lower end generally become fresh again. The actual time at which the delta channels become fresh depends upon the time of the first winter freshets of magnitude. This will be discussed in more detail in Chapter III. It is interesting to note that there appears to be a tendency for saline water to remain in the channels of the San Joaquin Delta later than in the channels imme- diately connected with the Sacramento River. This is illustrated very clearly by the salinity graphs for the year 1929. It will be noted that, in the month of December, when the salinity at 0. and A. Ferry was less than five parts per 100,000 parts of water, the salinity at the same time at many points in the San Joaquin Delta along Old and Middle rivers was "in excess of ten parts per 100,000 parts of Avater. This condition of a considerable degree of salinity remaining pocketed in the San Joaquin Delta occurred similarly in other years in the various branch channels of the San Joaquin River and also in the Mokelumne River. (See Table 33.) It is the result of the lack of a large enough flow from the San Joaquin River to flu.sh out the channels in the San Joaquin Delta. This same condition tends to occur in any channel invaded by salinity during the low water season until there is a fioAV down througli the channel in sufficient amount to flush out the saline water that has previously accumulated therein. The variation of salinity in the upper bay region is similar to that in the delta as shown by the available records from 1926 to 1929, inclu- sive. The minimum salinity at points in both Suisun and San Pablo bays is generally reached some time in the months of February, ]\Iarcli or April during the floods of the winter and spring. The actual mini- mum salinity and the maximum retreat of salinity in any year is generally coincident Avith the maximum flood of substantial duration. After reaching its minimum values and its point of maximum retreat for the season, the salinity gradually advances upstream, continuing until about the first of September. In any particular year, the salinity starts to increase earliest at the farther downstream points and at an increasingly later date at points farther upstream. TIius. in years when salinity retreats below Suisun Bay and the waters of Suisun Bay become fresh in the winter and spring months, the waters in the upper half of Suisun Bay usually remain practically fresh until May or June. Salinity at points farther downstream in the bay frequently closely approaches the seasonal maximum a considerable time before the actual ♦ In 1931 the invasion into the delta at Collinsville started in early April. 54 DIVISION OP WATER RESOURCES maximum ocoiirs, and the period of liigli degree of salinity, closely approaching the maximum, is longer than for points in the delta. Sea water has a salinity of about 1800 to 1900 parts of chlorine per 100,000 parts of water. As compared to this, the salinity at Point Orient during the period 1926 to 1929 has varied from a minimum of 350 to a maxi- mum of about 1900 parts. The minimum salinity in each season has varied from 350 to 1350 parts. At Point Davis near the westerly end of Carquinez Strait, the minimum seasonal salinity has varied from about 24 to 540 parts, with a maximum value of about 1850 parts during this period. Similarly, at Bulls Head Point, the minimum seasonal salinity during the period has varied from about 3 to about 240 parts, with a maximum of about 1690 parts during this period. All of these values of salinity are for the regular observations with samples taken in the surface zone after high tide. In January, 1930, eight additional salinity observation stations were established in the channels on the north side of San Pablo Bay, compris- ing two on Napa River, three on Sonoma Creek and branch channels and three on Petaluma Creek. These records indicate that, in these channels, salinity conditions are quite similar to those in the delta of the Sacramento and San Joaquin rivers. During the winter period of heavy run-off, these streams and the interconnecting channels generally are filled with fresh water. As stream flow diminishes after the spring, salt water advances upstream into the channels in a similar manner to that in the delta, salinity generally reaching a maximum in August or September. Saline water remains in these channels until winter runoff occurs in sufficient magnitude to push out the saline Avater. A very interesting condition as regards salinity exists in the chan- nels in the immediate vicinity of Stockton. It will be noted in the tabular and graphical record for 1929 that salinity in the channel at Stockton averaged about 100 parts all during the low water season. This high salinity affected the salinity in the river channel as far down as McDonald Pump during midsummer. Inasmuch as it was evident that this relatively high salinity in the channels at Stockton was not due to saline invasion from the bay, a special investigation was made for the purpose of determining, if possible, the source of this saline pollution. As a result of this investigation, it was found that the source of the snlinity in the channels in the vicinity of Stockton was the saline water discharged from twelve to fifteen natural gas wells oper- ated by a ]niblic utility in Stockton. The total amount of Avater dis- charged more or less continuously into the Stockton channel from these wells in 1929 amounted to approximately twelve to fifteen second- feet. With practically no fresh water coming in from the San Joaquin or the Calaveras rivers, this discharge of saline water having a chlorine content as high as 400 parts per 100.000 parts of water was sufficient to keep the salinity at about 100 parts in the Stockton channel all season and to affect the salinity to a marked degree at points some distance downstream. Extent of Saline Invnnon — The extent of saline invasion into the delta during each year of the period 1920 to 1930, inclusive, is shown on Plate III. The red lines on this map indicate the upstream limit of saline invasion each year to a degree of 100 parts of chlorine per 100,000 parts of water, and afford a means of visualizing the comparative extent VARIATION AND CONTROL OF SALINITY 55 of saline invasion for different years during the period. Tliey also show for each year the maximum extent to which the water in the channels of the delta was affected at some particular time of the season, with a degree of salinity assumed as too high for general irrigation use in the delta. Whether the application of water with a salinity of 100 parts of chlorine per 100,000 parts of water for the irrigation of crops in the delta would be harmful to crops or land is a question which has not been determined in this investigation. The toxicity of salts to crops depends upon many factors, including the character of the soil, drainage, method of irrigation and the type of crop itself. Some crops are known to be able to withstand more salt than others for any given soil and drainage conditions. IMoreover, many crops in the germinating and seedling stages will stand much less salt than the same crops when mature. Although it is difficult to set an exact limit, it has been assumed for average conditions in the delta that water having in excess of 100 parts of chlorine per 100,000 parts of water is not suitable for irrigation use. Hence this degree of salinity was chosen as the basis for the lines on Plate III depicting the maximum extent of saline invasion in different years. However, it should be understood that salinity of lesser degrees advanced to points upstream a considerable distance above the limiting lines of 100 parts shown on Plate III. The degree of salinity reached at points upstream in these different years may be obtained by referring to the tabular and graphical records of salinity. (See Table 33 and Plates V and VI.) The greatest invasion of salinity during the period 1920 to 1930 occurred in 1924, during or immediately following the driest season (1923-24) of record up to 1930 on the Sacramento and San Joaquin rivers.* In that j'ear at the time of maximum extent of invasion, the Avater in the channels of about 50 per cent of the delta had a salinity in excess of 100 parts. The dry years of 1920 and 1926 resulted in a smaller extent of invasion, the waters in the chan- nels of less than 20 per cent of the delta being similarly affected. In the years 1928 and 1929 and also 1930, le.ss than 10 per cent of the delta was similarly affected. In five years during the last ten, namely, 1921 to 1923, inclusive, and 1925 and 1927, the portion of the delta similarly affected was small even at the time of maximum invasion, being less than 5 per cent. It should be noted that the maximum extent of saline invasion usually occurs in late August or September, or in the latter part of the irrigation season. The maximum extent of saline invasion is usually also of short duration except for certain portions of the delta where the salinity becomes pocketed and remains for longer periods because of the lack of a sufficient inflow through these channels to flush out the saline Avater. The upstream limit of water having a salinity of 100 parts or more of chlorine per 100,000 parts of Avater gradually advances upstream from the loAver end of the delta over a period of two to three months. As a result, irrigation is curtailed on the loAver lands of the delta soon after iuA^asion starts, but at an increasingly later date on * Since the preparation of this report, the extremely dry season of 1930-31 has occurred, which resulted in an unprecedented saline invasion into the delta. At the time of its maximum extent, about 70 per cent of the delta had .salinity in excess of 100 parts of chlorine per 100.000 parts of water. The extent of invasion m 1931 is shown on Plate LXXXII. 56 DIVISION OF WATER RESOURCES lands progressively further upstream. Hence, a considerable portion of tlie delta area finally invaded with water having a salinity of 100 parts or more of chlorine per 100,000 parts of water has had water suitable for irrigation use until the latter part of the irrigation season, even in years of extensive invasion, such as 1924, 1920 and 1926. The observed maximum salinity for the season during the period 1920 to 1930 has varied between the following limits for typical stations in the upper bay and loAver delta: • Limits of variation of observed tnaximuni salijiity for season in parts of chlorine per 100,000 Station parts of water, 1920 to 1930 0. and A. Ferry 510 to 1345 Collinsville 358 to 1150 Antioch 179 to 1085 Jersev 33 to 708 Emmaton t44 to 802 Three Mile Slough 17 to 730 Rio Vista 4 to 608 The relation of the extent and degree of saline invasion to stream flow and other factors affecting the same will be fully discussed in a later portion of the report. Salinity of Drainage Water from Delta Islands — As stated in Chapter 1, the program initiated in 1929 included the taking of samples of drainage water on six of the islands in the delta, the points being selected with a view to obtaining conditions which might be representa- tive of the variable conditions of soil and crops in the delta. Staten Island, including stations at Camp 11 and Camp 35, was especially selected because of the fact that there was also the possibility of obtaining complete records of the amount of water diverted for irri- gation and drainage water pumped. Other stations were located on Mandeville, McDonald, Bacon and Jersey i.slands, representing the peat soil conditions in the San Joaquin Delta, and two stations on Grand Island in the Sacramento Delta, representing the silt soil condi- tions. The salinity records during the seasons 1929 to 1931 are sum- marized in Table 33. It is interesting to consider the relative magnitude of the salinity of the drainage water and that of the water in the adjacent river channels from which the supplies of irrigation water for the islands are obtained. For this purpose, Plate VII, "Comparative Salinity of River and Drainage Water," is presented. The records show con- siderable variation in the relative magnitude of the salinity of river and drainage water. On Staten Island the salinity of the river water in ceneral was someAvhat less than that of the drainage water, but the difference in salinity varied considerably during the season. In the months of July. August and September, 1929, the salinity was about the same. Following Se])tember and continuing during the winter months, the salinity of the drainau'e water increased while that of the river water decreased slightly. On ]\Iandeville, IMcDonald and Bacon • Maximum salinities for 19.31 were: O. and A. Ferrv — 1390, Collinsville — 1230, Antioch — 1240, .Jersey — 1170, Emmaton — 1000, Three Mile Slough — 860, Rio Vista — 740. t Estimated. No record. PLATE VII 20 10 "T — I — I — I — rr -Y T — I — I — 1 — r- "T — t — 1 — I — r Irrigation water being diverted from river 50 40 30 20 10 Mar. Apr. May June July 1930 ; COMPARATIVE SALINITY OF IVER AND DRAINAGE WATER 80995 — p. 56 510 to 1345 358 to 1150 179 to 1085 33 to 708 t44 to 802 17 to 730 4 to 608 56 DIVISION OF WATER RESOURCES lands progressively further upstream. Hence, a considerable portion of tlie delta area finally invaded with water having a salinity of 100 parts or more of chlorine per 100,000 parts of water has had water suitable for irrigation use until the latter part of the irrigation season, even in years of extensive invasion, such as 1924, 1920 and 1926. The observed maximum salinity for the season during the period 1920 to 1930 has varied between the following limits for typical stations in the upper bay and lower delta: * Litnits of variation of observed maxi7)iuni salinity for season in parts of chlorine per 100,000 Station parts of water, 1920 to 1930 0. and A. Ferry Collinsville Antioch Jersey Emmaton Three Mile Slough Rio Vista The relation of the extent and degree of saline invasion to stream flow and other factors affecting the same will be fully discussed in a later portion of the report. Salinity of Drainage Water from Delta Islands — As stated in Chapter 1, the program initiated in 1929 included the taking of samples of drainage water on six of the islands in the delta, the points being selected with a view to obtaining conditions which might be representa- tive of tbe variable conditions of soil and crops in the delta. Staten Island, including stations at Camp 11 and Camp 35, was especially selected because of the fact that there was also the possibility of obtaining complete records of the amount of water diverted for irri- eration and drainage water pumped. Other stations were located on Mandeville, McDonald, Bacon and Jersey islands, representing the peat soil conditions in the San Joaquin Delta, and two stations on Grand Island in the Sacramento Delta, representing the silt soil condi- tions. The salinity records during the seasons 1929 to 1931 are sum- marized in Table 33. It is interesting to consider the relative magnitude of the salinity of the drainage water and tliat of the water in the adjacent river channels from which tlie supplies of irrigation water for the islands are obtained. For this purpose, Plate VII, ''Comparative Salinity of River and Drainage Water," is presented. The records show con- siderable variation in the relative magnitude of the salinity of river and drainage water. On Staten Island the salinity of the river water in central was somewhat less than that of the drainage water, but the difference in salinity varied considerably during the season. In the months of July, August and September, 1929, the salinity was about the same. Following September and continuing during the winter months, the salinity of the drainage water increased while that of the river water decreased slightly. On Mandeville, ]\IcDonald and Bacon * Maximum salinities fnr 19.31 were: O. and A. Ferrv — 1390, Collinsville — 1230, Antioch — 1240, .Jersey — 1170, Emmaton — 1000, Three Mile Slough — 860, Rio Vista — 740. t Estimated. No record. PIRATE VII GRAND ISLAND JERSEY ISLAND BACON ISLAND .Salinitv of d ainajie water ^y^^-^- v^ "'^ <^ -- -..._ »'>,,^£^>^^J:;^^',j»«»»«o««- ftj .U:*,^'*^ ,, ... "^ STATEN ISLAND Mar. Apr. 1930 June July COMPARATIVE SALINITY or RIVER AND DRAINAGE WATER 80995 — p. 66 •t T- t T-r-p-r - -fir^'-V/Z.^- i4AM ^/'-^S'** <^! ■■■■'■'''''''•' ■ ,0£ 5 -'^Jo,, 0) o V -4- .:A-/ f- :i -i ■ esei .$uA xJuL ■^^^^^■ii . III m il . m^t^^mm bii .CJ iiH'\i'- VARIATION AND CONTROL OF SALINITY 57 islands, the salinity of drainage water was about the same as that of the river water during the irrigation season, while it exceeded that of the river water during the winter months. The conditions on Jersey Island in 1929-30 were markedly different than on the other islands. On this island the salinity of river and drainage water was about the same when the record started in the middle of July, 1929. Thereafter, during the months of July, August and September, the salinitj- of the river was greatly in excess of the drainage water, the river water reaching a maximum of 365 parts in early September. In i comparison, the drainage water reached a salinity of about 40 parts in I August and continued at about this degree until May, 1930, although I the salinity of the river water dropped below 10 parts in December, i 1929, and remained below 10 until July, 1930. It is stated that there ! were no irrigation diversions from August, 1929, to the latter part of \ April, 1930. Samples and analyses of drainage water on Sherman I Island during the 1929 season taken by Reclamation District 341, indicate a similar condition on this island. It appears from this record on Jersey Island and the data on Sherman Island that, in the lower part of the river where the channels become impregnated most every season with a relatively high degree of salinity, the water inside the island, at least that portion appearing in the drainage ditches, is unaffected. Definite conclusion as to this matter can not of course be made with but one year's record, but it appears that the shortness of the period of time in which water of a relatively high salinity sur- rounds the islands results in no appreciable effect on the water inside the islands, at least within the depth of the drainage ditches. It should be understood, of course, that, during this period of high salinity in tlie river channels, it is the usual practice not to divert water for irrigation. Hence, any effect of saline water in the adjacent channels j would be indicated presumably by an increase of salinity in the ground water within the island. Any increase in salinity of ground water would show up presumably in the drainage water, providing no water iwere being diverted for irrigation. The apparent lack of effect of relatively high salinity in the river channels on the water inside the islands is of significant importance in a consideration of the possible damage to the delta island lands and crops by reason of saline invasion. Based upon these records of comparative salinity of drainage water and river water, a study was made of the possible effect of irriga- jtion supplies and drainage pumping on the residual salt content of the islands in the delta. This inA^olved an estimate of the amount of salt entering and leaving the islands for the purpose of obtaining informa- tion as to whether more salt in the form of chlorine is being added to the lands by the irrigation water than is being taken out in the drainage Avater. In order to carry out such a study, it is necessary to have Irecords of the amounts of water diverted into the island and the [amounts of water pumped out by the drainage pumps. However, the study is complicated by the fact that there is also involved the extrae- itions of water consumed by the crops, vegetation and evaporation from soil and inland Avaterways; and also the water coming into the island from rainfall and by what may be termed seepage. It is well known tliat the amount of seepage from the channels into the islands is sub- stantial, especially in the lands of peat formation and that this source ,of supply materially contributes to the moisture requirements of crops t 58 DIVISION OP WATER RESOURCES and otlier moisture consuming agencies on the islands. However, no exact information is available as to the quantity or rate of seepage into the islands, as there is no method by which an exact measurement can be made of the same. Exact data as to total input and output of water Avere not available and hence only an approximate analysis could be made. On only one of the islands, Staten Island, was a fairly accurate record available of the irrigation diversions. It was possible to make a fairly close estimate of the consumptive use of water by crops, vegetation and evaporation, based upon detailed crop surveys and estimates from experimental measurements of the rate of use by the several types of crops, vegeta- tion and by evaporation. A study was then made setting up an equa- tion between the total amount of water entering an island (irrigation diversions, seepage and rainfall) and the total amount of water leaving the same (drainage pumping and consumption by crops, vegetation and evaporation). Based upon estimates of the amount of water entering and leaving the island over a year's period and the known saline content of the waters entering and leaving, it Avas possible to make an estimate of the total amount of salt brought in and taken out during a year's period. It was necessary, in making this estimate, to assume that the average elevation of the water table at the beginning and end of the period was the same. This is an approximation in which some error might be involved, but which is believed to be fairly reasonable for the purposes of this estimate. From the data on Staten Island and assuming an equality between the total amount of water entering the island and the total amount taken out during the year's period, it was demonstrated clearly that a con- siderable portion of the water supplj^ entering this island would have had to be supplied by what may be termed seepage. The data inclicated that slightly less than 50 per cent of the total water entering the island came through this source. A similar study for Jersey Island in 1929-30, using approximate estimates of irrigation diversions, indicated that seepage water comprised about the same proportion of the total water entering the island. On the other islands, no data were available on irrigation diversions, but an estimate of the total amount of water entering the island was made on the assumption that it would be equal to the total amount taken out. Thus, with available data upon which to estimate the amount of water pumped bj^ the drainage pumps and the amount of water con- sumed by crops, vegetation and evaporation, and an estimate of water added by precipitation, it was possible to estimate the amount of water entering the island by seepage and artificial diversions over a year's period. The estimates resulting from this study of the amount of salt put in and taken out of the islands are believed to be too approximate to present actual figures. The actual net amounts of salt which the esti- mates showed as being left in or taken out for the periods considered were generally small. Of chief interest, however, the estimates indi- cated for the period studied that about as much salt is being taken out of the islands in the drainage water as is entering the islands in the water diverted or seei)ing in. In order to obtain conclusive data as to this matter it would be necessary to have detailed records of the ground VARIATION AND CONTROL OF SALINITY 59 water levels in the islands and more exact data on the amounts of water entering and leaving the islands than have been available for the limited period studied. The matter is one intimately connected with the problem of alkali accumulation in the delta soils, which is recog- nized as a problem which should receive attention looking toward a suitable solution. Effect of Salinity Conditions on Developments and Interests. The invasion of salinity into the upper bay and delta channels in certain years since 1917 has affected not only the delta but also the industrial and urban developments in the upper Suisun Bay area, par- ticularly in the Antioch-Pittsburg district. The marshlands in upper Suisun Bay have also been affected to some extent. ]\Iany of the industries in the Antioch-Pittsburg district are large users of fresh water for boiler and various industrial process purposes. A large part of their fresh-water supplies have been obtained from the river or bay channels offshore from the plants. With the greater degree and duration of saline invasion in recent years since 1917, the industries have been curtailed in their use of this source of fresh-water supply and it has been necessary for them to obtain a greater portion of their required fresh-water supplies from local underground sources or from public water supply systems, entailing additional capital and a7inual costs. The local underground supplies are limited in amount and are already being drawn upon in excess of the average amount of natural replenishment. This has caused an infiltration of saline water from the adjacent bay or river channels, resulting in the underground supplies becoming saline and hence not fully dependable as a source of fresh-water supply. Industries lower dowTi in Suisun Bay and at points farther downstream have never been able to depend upon the immediate adjacent bay channels as a source of fresh-water supply because saline invasion has always resulted in the water remaining too salty for fresh-water purposes during a considerable portion of the year. Hence, in so far as fresh-water supply is concerned, the change in salinity conditions during the last ten to fifteen years has not affected these loAver intere.sts, except the California and Hawaiian Sugar Refining Corporation. Beginning in 1920, this company found it more economical to obtain its fresh-water supply in the summer and fall months from Marin County instead of by barges filled in the river above, because of the greater distance that had to be covered to reach fresh water. This latter arrangement was not wholly satisfactory and led to this company constructing a new private water supply system in 1930 to furnish fresh water for the sugar factory and the city of Crockett. Water is obtained from wells in lower Napa Valley and con- veyed to Crockett by pipe line. The greater degree and duration of saline invasion in the Suisun Bay channels has also affected the industries to some extent by reason of the increased rate of depreciation on cooling water equipment due to the greater corrosion caused by the salt water pumped from the bay for cooling and condeu'sing purposes. Many of the industrial plants have had to replace their previous cooling equipment with salt-resisting equipment in order to decrease the expense of maintenance and depre- ciation. However, the additional cost of salt-resisting equipment does 60 • DIVISION OP WATER RESOURCES not greatly increase the expense of cooling water to the industries and the actual cost per 1000 gallons is small. Over 80 per cent of the total amount of water used by industries in the upper bay region is for cooling and condensing purposes. The use of saline water from the bay channels for cooling and condensing is satisfactory and little, if any, advantage would be gained if fresh water were available for this pur- pose. From 1880 to 1920, Pittsburg (formerly Black Diamond) obtained all or most of its domestic and municipal water supi)ly from New York Slough offshore. Although the records show that the water became too brackish to be suitable for domestic use during certain periods in the summer and fall months even before 1917 (See Table 34 for record of salinity, 1910 to 1916), the degree and duration of salinity greatly increased from 1917 on and necessitated the provision of a new source of supply. After providing temporary expedients, including the haul- ing of water in barges filled at points upstream where fresh water was available, the use of the river as a source of domestic and municipal water supply was discontinued in 1920 and since that time the supply has been obtained from local wells. From early days, Antioch has obtained all or most of its domestic and municipal supply from the San Joaquin River immediately offshore from the city. This supply also has ah^ays been affected to some extent by saline invasion Avith the water becoming brackish during certain periods in the late summer and earlj' fall months. However, conditions were fairly satisfactory in this respect until 1917, when the increased degree and duration of saline invasion began to result in the water becoming too brackish for domestic use during considerable periods in the summer and fall. To meet this change in conditions, Antioch finally constructed a reservoir which is filled with fresh water from the river in the winter and spring and which is designed to sup])ly the city during the period of the year when the Avater in the river is too brackish for municipal use. The remaining cities and towns in the upper bay region have obtained fresh-water supplies from A-arious local sources such as sur- face streams and aa'cIIs and hence have not been affected by recent changes in salinity conditions. One public utility, serving the cities and toAA'ns of Contra Costa County from Pittsburg to Oleum as well as several industrial jilants, has recently completed a new Avater supply development, pumping water from the lower river near ^lallard Slough about tAvo miles Avest of Pittsburg and piping the same to a storage reservoir at Clyde just south of Bay Point. Water is pumped Avhen fresh and free from saline invasion and the storage ca]iacity is designed to .supi^ly the demands during the remainder of the year Avhen the water at the intake is too salty for fresh-AA^ater purposes. The marshlands adjacent to Suisun Bay, especially the portion thereof in the upper half of the bay, liaA-e been affected to some extent by the more prolonged invasions of salinity of high degree since 1917. Although the area farmed is relatively small in extent, comprising only 5000 acres in 1929, Avater suitable in qualitj^ for irrigation has been available for much shorter periods during the last ten to fifteen years than in former years. This not only has curtailed irrigation diA^ersions to crops, but also has limited the dcA-elopment of these marshlands because of the lack of aA-ailability for a sufficient period of time of fresh water for leaching the salts from the soils to make them fit for crop I VARIATION AND CONTROL OF SALINITY 61 production. In former years these lands were utilized principally for cattle grazing and dairying. These activities have been adversely affected during recent years because of the difficulty in providing fresh water for the cattle during the more prolonged saline invasions. Except for those specifically noted heretofore, the industrial, muni- cipal and agricultural developments and interests in the upper San Francisco Bay region have not been affected thus far by saline invasion in regard to water supply, because the river and bay channels have not been used as a source of fresh-water supply. However, the studies pre- sented in other reports * show that the ultimate water requirements for industrial, municipal and agricultural use in the upper bay region will necessitate the importation of supplies from some suitable source to supplement the local water resources which are capable of economic development. The nearest source of supply would be the lower Sacra- mento and San Joaquin rivers. The studies of water supply, yield and demand in the operation of the initial and ultimate developments of the State Water Plan show that most of the water supply required to be imported to the upper San Francisco Bay region could be furnished from this source. Therefore, the industrial, municipal and agricultural developments adjacent to Suisun and San Pablo bays are directly inter- ested in the investigation of salinity, and particularly in the determina- tion of a means of controlling saline invasion in such a way that water supplies now available or hereafter made available in the lower Sacra- mento and San Joaquin rivers would be maintained fresh at all times for diversion to supply the future needs of the upper bay region. One of the results attributed to the increased degree and duration of saline invasion of the last ten to thirteen years is the destruction by the teredo of untreated timber piling in water-front structures along the shores of San Pablo and Suisun bays. Prior to 1919, most of the water- front structures in the entire upper bay region w^ere supported on untreated timber piling, most of which had stood for many years without molestation by marine borers. The marine borer, known as the teredo navalis, was first reported in a structure at Mare Island in 1914, but its activities did not become serious until after 1917. By 1921, practically all untreated timber piling in the upper bay region had been destroyed b}^ the teredo navalis and necessitated costly reconstruction with various forms of treated timber and concrete piling designed to resist the attacks of these borers. It should be noted, however, that the salinity of the water in San Pablo Bay and most of Suisun Bay was great enough prior to 1917 for the teredo to be active, and had it not been for the introduction of the teredo navalis into the upper bays, probably in a shipment of piling infested with this borer, the untreated timber piling would not have been attacked. Hence, it appears that the change in salinity conditions, in itself, was not the primarj^ cause of the destruction of untreated timber piling, but rather only a contribut- ing factor, providing conditions agreeable to the activities of teredo navalis after its introduction. Within the delta, the greater extent, degree and duration of saline invasion in certain years since 1917 have resulted in the curtailment of irrigation on varying portions of the delta during the latter part of the * Bulletin No. 25, Report to Legislature of 1931 on State "Water Plan, Divi- sion of W^ater Resources, 1930. Bulletin No. 28, Economic Aspects of p. Salt Water Barrier below Confluence or Sacramento and San Joaquin Rivers, Division of Water Resources, 1931. 62 DIVISION OF WATER RESOURCES irrif^atioii season. This has rosultod possibly in some decrease in crop yields but no definite information lias been found as to any losses in crops for any year up to 1930. t This no doubt is partly due to the judicious choice as to type of crops grown especially on the lower lands of the delta such as Sherman and Jersey islands. It is found that the crops grown on these lower lands are generally of a type which have the greatest tolerance to saline conditions and/or which do not require irrigation applications in the late irrigation season. Thus, one of the chief crops grown is asparagus, which is relatively tolerant to salt and which, being deep-rooted, draws its moisture from considerable depths and hence does not require irrigation applications in the late summer and fall months. Shallow-rooted crops requiring irrigation in the latter part of the irrigation season usually are not planted on these lands where saline invasion generally occurs in the adjacent channels to make the water unsuitable for irrigation use. Earlier, more prolonged and more extensive invasions of salinity than have occurred up to 1930 might result in material loss in crop production. t There has been considerable speculation upon the effect of saline invasion on the quality of the lands within the delta. In so far as can be ascertained by the present investigation, the invasions of salinity which have occurred up to 1930 apparently have not affected the quality of land. This appears to be true even for those lands which lie nearest the lower end of the delta, including such areas as Sherman, Jersey, Bradford, Twitchell, and Brannon islands and the Webb Tract. The waters in the channels adjacent to these lands have been invaded by saline Avater to an extent sufficient to make the water unfit for irriga- tion use during varying periods in several of the jiast ten years. How- ever, the period of saline invasion into the delta is usually about three to six months of the summer and fall in the lower delta channels and correspondingly lesser periods at points farther upstream. Just what the effect of a longer period of saline invasion than has been experienced up to 1930 would be on these delta lands is impos- sible to state, nor can a statement be made with any degree of certainty as to what period of saline invasion could be experienced by these lands without affecting their quality. It appears probable that the saving feature in the conditions which have been experienced during the past ten years or even farther back is the fact that fresh water is present in the adjacent channels for a larger portion of the year and is therefore the predominating source of the ground water supplies which fill the voids in the island masses. A fresh water supply thus stored up in the ground is available for a considerable period of time and apparently its quality within the reach of plant roots is unaffected by invasions of saline water in the adjacent channels which extend over periods of considerable duration. However, if water of a high salinity were to remain present in the channels of the delta during a larger portion of the year, it appears probable that the ground waters in the islands would gradually become saline and thus affect the quality and utilization of the soil. Conditions would tend to approach those which are found in the marshlands of Suisun Bay, where saline water conditions have predominated over a longer period of time. t Surveys and studies under way indicate that the uprecedented saline invasion in 1931 resulted in a very material loss in crops in the delta and also some loss in the delta uplands. I VARIATION AND CONTROL OF SALINITY 63 Although the evidence appears to show that the delta lands and crops have not been materially damaged by saline invasions which have occurred up to 1930, the salinity menace has tended to depreciate land values in the delta. Until this menace is rem6ved there exists a more or less constant threat of more extensive and prolonged saline invasions than have heretofore occurred up to 1930, which might result in material damages to crops and lands in the delta. There does exist a more or less serious problem of salt accumula- tions in the soils of the delta islands which it is deemed desirable to discuss in this connection, inasmuch as there has been a considerable tendency to confuse this problem with the invasions of saline water from the bav. Because of the method of irrigation in the delta with ground water levels held from six inches to three feet below the ground surface to supply the moisture requirements of the crops, there results a positive tendency for the gradual accumulation of salts in the surface layers of the soil. This is due to the fact that capillary action draws the moisture from the water table to the ground surface and upon evaporation leaves in the surface layers of the soil whatever salt con- tent it had. Where the water is generally very pure and contains but a small amount of salts, the accumulation of salt by this action is extremely slow and it takes many years to accumulate enough salt to affect crop production. AVhile the water supply in most of the delta is usually comparatively free from salt, the result of many years of irriga- tion under the methods used has been the gradual accumulation of con- siderable amounts of salt in the surface layers of some of tlie island soils. Direct rainfall, when of sufficient quantity, helps considerably in leach- ing out such accumulations. However, during periods of subnormal precipitation such as the last thirteen years, the leaching action of rainfall is greatly diminished. Thus far the problem has not reached serious proportions except in a few isolated instances. However, the evidence of actual accumulations is sufficientl.y clear to have brought it to the attention and serious consideration of many of the delta land owners. It is evident that measures should be taken before many years to eliminate these accumulations of salt which tend to gradually occur. The evidence shows that the salt which has been accumulated in the surface layers of soils in the delta is chiefly the result of the methods used in irrigation involving the maintenance of high water tables for the growing of crops. However, it is important to point out that fresh water is especially essential with this method of irrigation, as the use of water of greater salinity would tend to increase salt accumulations in the soil. Basic Factors Governing Salinity Conditions. The basic factors governing the extent of saline invasion and retreat and the rates of advance and retreat of salinity are stream flow into the delta and tidal action. The effect of stream flow is modified by consumption of water in the delta by crops, vegetation and evapora- tion. In other words, the stream flow at the confluence of the Sacra- mento and San Joaquin rivers into Suisun Bay is the difference between the stream flow into the delta and the amount of water con- sumed within the delta. The studies of variation and control of io! salinity are chiefly directed to the determination of the relation of the siJ 64 DIVISION OF WATER RESOURCES variation of salinity to the basic factors affecting the same, namely; stream flow and tidal action. It has, therefore, been essential to obtain as accurate and complete data as possible as to these basic factors and the compilation of the data regarding the same has been an important part of the present investigation. Stream Flow— The records of stream flow used in this investigation are from measurements made at established gaging stations maintained and operated by the United States Geological Survey in cooperation with the State together with special stream gaging stations maintained and operated by the State alone. The location of the stream gaging stations from which records of flow are used in this report are shown on Plates I and II. These gaging stations have been in operation for varying periods of time. During earlier years, most of the gaging stations established and operated were on the main streams at or near the rim of the valley. For the purpose of this investigation it was necessary to determine the inflow into the delta. Fortunate!}", during the past ten years since 1920, stations have been maintained and operated at or near the rim of the delta which has made it possible to closely estimate daily inflow into the delta, especially during the summer and fall months covering the period of invasion and retreat of salinitv. These records of daily inflow into the delta, for the seasons 1919-1920 to 1928-1929 j have been compiled and are presented in tabular and graphical form. Table 37 summarizes the daily infloAv into the delta for both the Sac- ramento and San Joaquin River systems separately and combined from 1919 to 1929, inclusive. The basis of compilation of the figures on inflow are presented in detail with the table. The Sacramento River flow includes the flow of the main Sacramento River and all of its branches into the northern end of the delta, as measured at Sacramento. It also includes the flow of Cache and Putah creeks and Yolo By-Pass. The San Joaquin River flow includes the flow of the San Joaquin River as measured at the south rim of the delta near Mossdale Bridge, together with the flow of the Calaveras, JNIokelumne, and Cosumnes rivers and Dry Creek. These records of daily inflow into the delta are graphically pre- sented on Plates V and VI. These are shown by the diagrams on the lower half of these plates directly below the grapliical record of salinity so that the variation of infloAv into the delta can be directly and con- veniently compared with the variation of salinity. The heavy lines on the graph of stream flow are for the combined flow of the Sacrament and San Joaquin rivers into the delta. There is also shown in lighter line the flow alone of the San Joaquin River and its branches During the low flow period of the summer and fall months, the stream flow is shown each season on a larger scale so that the amounts of flow can be more readily taken off the graph. There is also shown on the larger-scale diagrams of flow the consumption of water in the delta, based upon estimates and data presented hereafter. This is shown for the entire delta and also separately for the Sacramento and San Joaquin deltas. The assumed dividing line between the Sacramento and San Joaquin deltas is shown on Plate III. The direct comparison between the stream flow into the delta and the consumption of water in the delta can be readily made on this graph which clearly illustrates the fact that, in several of the years during the ten-year period, the n i VARIATION AND CONTROL OF SALINITY 65 stream flow entering the delta has been insufficient to take care of the consumptive needs of the delta. Prior to 1919, stream flow measurements are not available for estimating the daily inflow into the delta. However, the records avail- able are sufficient to make a reasonably close estimate of the monthly inflow as far back as 1911-1912. The monthly stream flow has, there- fore, been compiled for the period 1911 to 1919 for use in general studies as to relation of stream flow to salinity. The estimated monthly stream flow from 1911 to 1929 is shown in Table 38 and on Plate VIII, "Monthlv Stream Flow into Delta of Sacramento and San Joaquin Rivers."^ Table 39 summarizes the seasonal stream flow and the per cent of each season's stream flow to the average for the 58-year period, 1871 to 1929. The estimates of seasonal stream flow from 1871 to 1911 are not shown in Table 39, because only an approximate estimate could be made based upon the estimates in a previous report * and records of stream measurements at stations at the rim of the valley. However, the inflow for the seasons prior to 1911 has been estimated as a per- centage of the 58-year mean (1871-1929) and shown w^ith the per- centage estimates from 1911 to 1929 on Plate IX, "Seasonal Stream Flow in Delta of Sacramento and San Joaquin Rivers." The per- centage estimates of seasonal stream flow were made for the seasons prior to 1889, because it was desirable to correlate these earlier years' stream flow with historical information available on salinity conditions. Variation of Stream Flow — Stream flow into the delta varies in magni- tude in accordance with the wetness of the year. The mean seasonal stream flow into the delta for the period 1871 to 1929, inclusive, is estimated at 31,346,000 acre-feet. The 40-year mean from 1889 to 1929, inclusive, is practically the same amount. The mean for the last 20, 10- and 5-year periods is, however, considerably less than the long period means, the 20-year mean being estimated at 23,765,000 acre-feet and the 10- and 5-year means being about 19,000,000 acre-feet. During the last 58 years, the period up to and including 1916 contains a preponderance of wet or above normal years. As shown on the upper diagram of Plate IX, the accumulated percentage departure of seasonal stream flow from mean stream flow for the period 1871 to 1917 amounted to about 500 per cent excess above the 58-year mean. Begin- ning with the season 1916-1917, however, there has been a jn-eponder- ance of dry years up to 1930, the effect of wliich is indicated by the almost continuous downward slope of the cumulative curve of ])ercent- age de])arture from the mean. The total stream flow for individual seasons varies widely. Based on the 58-year mean (1871-1929), the percentage of mean seasonal stream flow varies from a minimum of 18 per cent for the season 1923-1924 to a maximum of 261 per cent for the season 1889-1890.** During the 58 years there have been 29 years in which the stream flow * Bulletin No. 5, Flow in California Streams, Division of Engineering and Irrigation, 1923. ** The percentages of mean seasonal stream flow into the delta are affected by upstream diversions and, hence, differ for identical seasons from corresponding per- centages of mean run-off naturally tributary to the delta. Upstream diversions effect a proportionately greater reduction of the tributary run-off in dry seasons than in wet seasons. Therefore, especially in dry seasons, the percentage indexes for stream flow into the delta are considerably less than those for the natural tribu- tary run-off of the same seasons. 5 — 80995 66 DIVISION OF WATER RESOURCES was equal to or greater than normal. However, in the 10-year period, 1919-1929, only two seasons have had normal stream flow and of the remainder, four have had but 50 per cent or less of normal stream flow. In the 13-year period, 1917-1929, there have been but two normal seasons of stream flow and of the balance, five seasons have had a total stream flow of 50 per cent or less than normal. It is particularly important to note that the period 1917-1929 has been one of unusual dryness and subnormal stream flow and that this condition has been a most important contributing factor to the abnormal extent of saline invasion which has occurred during this same time. Other factors which will be discussed hereafter have contributed to the salinity con- ditions, but the conditions of subnormal stream flow are believed to have been a major factor in bringing about the abnormal salinity conditions. Even more marked variations occur in monthly stream flow into the delta. As shown in Table 38 and on Plate VIII, the monthly stream flow has varied from a minimum of 70,000 acre-feet in 1920 to a maximum of over 12,000,000 acre-feet in 1914, with an average of 1,845,000 acre-feet per month for the period 1911-1929, The average of the maximum monthly stream inflows for all seasons from 1911 to 1929 is 4,916,000 acre-feet. The smallest maximum monthly stream flow in any season during the period was in 1923-1924 and amounted to 1,254,000 acre-feet. For the thirteen-year period 1917 to 1929, the average monthly stream flow was 1,604,000 acre-feet. The minimum monthly stream flow from 1911 to 1929 during the summer period June to September, inclusive, in each season, ranged from 70,000 acre- feet in 1920 to 557,000 acre-feet in 1912, The months of large stream flow generally occur in the period December to May corresponding with the winter and spring flood period. During the earlier months of December to March, inclusive, the larger stream flows are caused usually by rainfall in the valleys and foothill areas, occasionally augmented by melting snow in the lower mountains. It is in this period that most of the large floods have occurred. In the later months, April, May and June, the larger stream flows usually come directly from melting snows in the Sierra Nevada. Based on this period of record, 1911-1929, stream inflow during the six months' period, Januaiy to June, inclusive, on the average comprises 82 per cent of the total seasonal stream flow and during the seven months' period, December to June, inclusive, 88 per cent of the total seasonal stream flow. This leaves but twelve to eighteen per cent of the total seasonal stream flow occurring during the five or six summer and fall months up to the time that rains and winter freshets start normally each year. It is during this latter period that the maximum demands for irrigation and water consumption occur and this situation typifies the usual discrepancy which exists in California as between the occur- rence of supply and demand for water. The period of low stream flow is also coincident with the annual invasion of salinity into the upper bay and delta channels. The variations in rate of flow of the Sacramento and San Joaquin rivers into the delta are even more marked and of greater significance than the variations in monthly and seasonal inflow. During the period 1919 to 1929, inclusive, the combined flow of the Sacramento and San Joaquin rivers into the delta has varied from a minimum of about 700 PLATE VIII 1926 1927 1928 1929 i/IONTHLY STREAM FLOW INTO DELTA OF SACRAMENTO AND SAN JOAQUIN RIVERS 66 DIVISION OF WATER RESOURCES was equal to or greater than normal. However, in the 10-year period, 1919-1929, only two seasons have had normal stream flow and of the remainder, four have had but 50 per cent or less of normal stream flow. In the 13-year period, 1917-1929, there have been but two normal seasons of stream flow and of the balance, five seasons have had a total stream flow of 50 per cent or less than normal. It is particularly important to note that the period 1917-1929 has been one of unusual dryness and subnormal stream flow and that this condition has been a most important contributing factor to the abnormal extent of saline invasion which has occurred during this same time. Other factors which will be discussed hereafter have contributed to the salinity con- ditions, but the conditions of subnormal stream flow are believed to have been a major factor in bringing about the abnormal salinity conditions. Even more marked variations occur in monthly stream flow into the delta. As shown in Table 38 and on Plate VIII, the monthly stream flow has varied from a minimum of 70,000 acre-feet in 1920 to a maximum of over 12,000,000 acre-feet in ]914, with an average of 1,845,000 acre-feet per month for the period 1911-1929. The average of the maximum monthly stream inflows for all seasons from 1911 to 1929 is 4,916,000 acre-feet. The smallest maximum monthly stream flow in any season during the period was in 1923-1924 and amounted to 1,254,000 acre-feet. For the thirteen-year period 1917 to 1929, the average monthly stream flow was 1,604,000 acre-feet. The minimum monthly stream flow from 1911 to 1929 during the summer period June to September, inclusive, in each season, ranged from 70,000 acre- feet in 1920 to 557,000 acre-feet in 1912. The months of large stream flow generally occur in the period December to May corresponding witli the winter and spring flood period. During the earlier months of December to March, inclusive, the larger stream flows are caused usually by rainfall in the valleys and foothill areas, occasionally augmented by melting snow in the lower mountains. It is in this period that most of the large floods have occurred. In the later months, April, May and June, the larger stream flows usually come directly from melting snows in the Sierra Nevada. Based on this period of record, 1911-1929, stream inflow during the six months' period, January to June, inclusive, on the average comprises 82 per cent of the total seasonal stream flow and during the seven months' period, December to June, inclusive, 88 per cent of the total seasonal stream flow. This leaves but twelve to eighteen per cent of the total seasonal stream flow occurring during the five or six summer and fall months up to the time that rains and winter freshets start normally each year. It is during this latter period that the maximum demands for irrigation and water consumption occur and this situation typifies the usual discrepancy which exists in California as between the occur- rence of supply and demand for water. The period of low stream flow is also coincident with the annual invasion of salinity into the upper bay and delta channels. The variations in rate of flow of the Sacramento and San Joaquin rivers into the delta are even more marked and of greater significance than the variations in monthly and seasonal inflow. During the period 1919 to 1929, inclusive, the combined flow of the Sacramento and San Joaquin rivers into the delta has varied from a minimum of about 700 I PLATE VTII 191) r9l2 1913 LEGEND r/////A Sacramento Rjver System L I San Joaquin River System TTTTTTTTTTTTTTTTTTTTTT I I I I I I I I I I I I H 11 I I I I I I I M I I 1920 1921 192 2 1923 192 4 192 S 19 2 6 1927 1928 1929 MONTHLY STREAM FLOW INTO DELTA OF SACRAMENTO AND SAN JOAQUIN RIVERS PLATE IX 58 year 40 •■ 20 ■' 10 •• 5 •• mean stream flow Sacramento River 23,449,000 acre-feet 23,442,000 •• •• 18,228.000 •• •• 14,995,000 •• 16,058,000 •• San Joaquin River 7.897,000 acre-feet 7,805.000 •■ 5,537,000 ■• •• 4,136,000 ■• •■ 3,599,000 •■ Combined 31.346.000 acre-feet 31,247,000 •• •• 23,765,000 •■ •• 19,131.000 •• •• 19,657,000 ■• •• LEGEND Sacramento River San Joaquin River Combined Sacramento and San Joaquin Rivers S0995— p. C6 SEASONAL STREAM FLOW INTO DELTA OF SACRAMENTO AND SAN JOAQUIN RIVERS VARIATION AND CONTROL OP SALINITY 67 seeond-feet in August, 1920, to a maximum of 353,000 second-feet in Marcli, 1928. As far as is known, the minimum flow in 1920 is the smallest combined flow of the Sacramento and San Joaquin rivers into the delta that has ever occurred up to 1930.* At the time this mini- mum flow occurred, about half of the flow was supplied by the Sacra- mento River and about half by the San Joaquin River and its branches. From July 24 to August 23, 1920, or practically a month's period, the combined inflow ranged from 700 to 1600 second-feet with an average of about 1000 second-feet. In the summer of 1924, the minimum flow was nearly as small as in 1920, decreasing to about 1000 second-feet in the middle of July of that year. From July 1 to August 15, 1924, the aver- age flow into the delta w^as about 1300 second-feet. In the summer of 1926, the minimum flow^ was 1600 second-feet with an average flow from July 20 to August 12 of about 1800 second-feet. As compared to these lower minimum flows which have occurred during the period 1920- 1929, the minimum flow in 1928 was 3100 second-feet and in 1929 about 2600 second-feet, while in the more normal years of 1921, 1922, 1923, 1925 and 1927, the minimum flow Avas at all times greater than 3000 second-feet, and, wdth the exception of 1921 and 1925, was over 4000 second-feet. The minimum flow of the Sacramento River into the delta during the ten-year period was about 300 second-feet about August 1, 1920, as compared to about 700 second-feet in July, 1924, while the minimum flow of the San Joaq-uin River and its branches into the delta was about 200 second-feet in 1920, and 300 seeond-feet in 1924. In 1926 the minimum flow of the Sacramento River was 1300 second-feet while the minimum flow of the San Joaquin River was 200 second-feet. The greater portion of the stream flow into the delta usually has come from the Sacramento River. The graphical record of flow on Plates V and VI clearly illustrates the proportionate amounts supplied from the two streams. This is of particular significance in the summer period. During the ten-year period from 1920 to 1929, except 1923 and 1927, the flow of the San Joaquin River and its branches has dropped below 1000 second-feet and in most years to 500 second-feet or less for a considerable period in the summer of every year, whereas in only two years, 1920 and 1924, did the flow of the Sacramento River into the delta reach such a low discharge.* Therefore, it is clear that the Sacra- mento-San Joaquin Delta is dependent to a large extent upon the flow of the Sacramento River into the delta for its water supply. It is equally clear that the usually greater flow of the Sacramento River is of relatively greater importance in the effect of stream flow on salinity conditions in the delta and uj)per bay channels. The maxi- mum flow of 353,000 second-feet, which occurred during the ten-year period (1920-1929) is considerably less than the maximum flow^s w^hich maj^ be likely to occur in future years. It has been estimated that the maximum flood discharge of the combined Sacramento and San Joaquin ♦Since the preparation of this report, the extremely dry season of 1930-31 has occurred, resulting in an unprecedented minimum flow into the delta during the sum- mer of 1931. The combined flow of the Sacramento and San Joaquin River systems into the delta was less than 500 second-feet for a considerable period during the summer ; and, for a period of about two weeks, there was practically no flow passing Sacramento in the Sacramento River. The only flow coming into the delta during this period comprised return water from lands irrigated on the San Joaquin River system and some water released from reservoirs on the Mokelumne River. 68 DIVISION OF WATER RESOURCES rivers into the delta under present conditions of reclamation and flood control develoi)ment might reach a maximum of between 750,000 and 800,000 second-feet. The amount and variation of stream flow into the delta during the summer and fall months are of chief significance and importance as affecting the extent, degree and duration of saline invasion into the upper bay and delta channels. The amount and variation of Avinter and spring flows, and especially the floods, chiefly atTect the extent of retreat of .salinity. However, the amount and variation of winter and spring flows also have a material effect upon the succeeding summer invasion of salinity. This feature will be discussed more fully in Chapter III. Consumptive Use of Water in Delta — The consumptive use of water in the delta of the Sacramento and San Joaquin rivers is based chiefly upon six years of tank experiments made by the United States Depart- ment of Agriculture in cooperation with the State as previously described in Chapter I. The complete report of these measurements has not as yet been prepared. HoAvever, a summary of the results of the measurements has been made especially for this investigation, which furnishes what may be considered reasonably close figures on estimated water consumption b}- crops, vegetation and evaporation in the delta. In the data and discussions presented herein, the term "consumptive use'.' is used in its absolute sense. It represents amounts of Avater consumed irrespective of source and hence includes amounts consumed from rainfall. HoAvever, the greater part of both annual and seasonal consumption occurs in the dry months, and hence the source of supplj' is chiefly from the delta channels. Table 1 shoAvs the estimated consumptive use in feet depth (acre- feet per acre) for all important crops and, in addition, for natural A'ege- tation, and evaporation from bare and idle land and open Avater. These rates of estimated consumptive use of Avater Avhen applied to the acreages of crops, natural vegetation, idle land and open Avater surface give the Avater consumed in the delta in acre-feet. The esti- mated monthly, total seasonal and total annual consumption in acre- feet in 1929 are shown in Table 2. The total seasonal consumption comprises tlie estimated amounts of Avater used by crops and A'egetation during tiie groAving season and by evaporation for the entire year. The total annual consumption includes, in addition, the use of water on the cropped area during the nongroAAJng or dormant season. The consumptive areas are based upon th(> 1929 crop surveys of the Sacra- mento-San 'loatiuin Water Supervisor, supplemented by special surve3\s and compilations made for this report. Crop areas are available for all years from 1924 to 1929. inclusJAe. No reliable complete data are aA'ailable for the years 1920 to 1923, inclusiA-e. HowcA-er, as shoAvn in Table 3, Avhich summarizes the area in irrigated crops and the estimated total seasonal consumption of water by crops from 1924 to 1929, inclusive, there has been no A'ery great change in the irrigated crop area during tliese years and it is probable tliat the irrigated area Avas about the same as far back as 1920. The average depth of Avater used by irrigated crops in the entire delta, as estimated from the con.sumpti\'e use figures adopted, is about 2.1 feet during the composite growing season of all crops. 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"rt CM lO -H CM -^ to .So ci" r-T --r i>r 00 o tC s — ^ CM CM C^l CM CM CO CM 03 "r CM CM CM CM CM CM CM s a: "Sfe s H§ a 03 »ri OQ GO OOOOOO O c oooooo o o CO O CO CO C^l O I^ o « S ^'^'■co-i'''ro*co" CM ^_ £: OOOOOO o CS'C O ^ ^H^H *^ M ^ « OJ CS ». -^ ^ Ci CM o» ki 03 a> o >- -*}» uo CO r^ CO OS CM CM CM C OS i 1 .— 1 1— ( ^H 1— 1 .— I .— « 74 DIVISION OF WATER RESOURCES In compiling the area of irrigated crops, it is assumed that all crops planted on lands which lie below an elevation of five feet above mean sea level consume water from the delta channels even though no artificial diversion of water with siphons or pumps is made for irriga- , tion. The assumption is based upon the fact that the average water ) level in the delta is about 1.5 feet above mean sea level and reaches higher levels each day, and the high water table in the islands resulting therefrom affords "an opportunity for the plants to obtain their moisture without artificial diversions. HoAvever, most of the crops in the delta are irrigated by artificial diversions. The total consumptive use of water has been estimated for the Sacramento and the San Joaquin deltas separately and for the entire delta. The line of division assumed between the Sacramento and San Joaquin deltas is based upon the source of water supply, the Sacramento Delta embracing all those lands which obtain their water supply from the Sacramento Kiver channels -and the San Joaquin Delta all those lands which obtain their supply from the San Joaquin River channels, including its branches, the Mokelumne and Calaveras rivers, as well. This division line is shown on Plate III. Plate X, "Consumptive Use of Water in Delta of Sacramento and San Joaquin Rivers," graph- ically" shows for all months of the year the consumptive use of water in the Sacramento and San Joaquin deltas separately and combined and the proportionate use of the total consumption by each crop and water-using agency. Crop acreages for 1029 are used in the compila- tion of this graph. The results for other years during the last 10 would be quite similar in the total use but with certain variations as to the proportionate use by different crops and other agencies. The estimated monthly consumption shown in Table 2 for each individual water use was plotted cumulatively on the vertical scale.* The lines on the graphs are drawn as smooth curves through the plotted points. The areas, designated by index number between the curved lines, as compared to the total area under the upper curved line of each graph give a graphical representation of the proportionate use of the total consumption by the different crops and agencies. As shown by this graph and the tabulations, the present estimated consumptive use of water in the entire delta varies from a minimum of about 800 acre-feet per day or 400 second-feet during the winter months to a maximum of about 7400 acre-feet per day or 3700 second-feet at the peak of the irrigation season, which occurs about the middle of August. The total annual consumption in 1029 by irrigated crops, compris- ing 321,800 acres, averages 2.6 feet in depth. The difference between tliis amount and the total seasonal use by the irrigated crops of 2.1 feet in depth is due to soil evaporation and use by weeds and similar vegetation on the cropped areas dui-ing the nongrowing or dormant season. As a coincidence, the total annual consumption for the gross area of 488,600 acres and the total seasonal consumption for the total consumptive area of 420,900 acres (see Plate X) also averages 2.6 feet in de]ith. It is of particular interest to note the large amount of * In plotting and tabulating the consumption and consumptive areas on Plate X, certain items in Table 2 were combined. The area shown for index No. 11 includes 9500 acres of pasture. 1800 acres of brush and oaks, 3700 acres of weeds and 5600 acres of willows, total inpr 20,600 acre."?. Under the summary in the tabulation, the area of pasture is included with other irrigated crops ; brush and oaks with tules and willows as natural vegetation ; and weeds with the idle land below elevation 5.0. PLATE X LEGEND Area in acres ir delta Seasonal Crops or classification consumptive use of water In feet depth Sacramento San Joaquin Combined Grain and ha_y 6,100 63,900 70,000 1.7 Asparagus 29,100 33,400 62^00 2.7 Alfalfa 8,600 15,900 24,500 3.2 Beans 18,200 14,300 32,500 \3 Beets 7,300 11,000 18,300 2.3 Corn 5,«00 35,600 41,000 2.4 Fruit 12,600 2,400 15.000 2.3 Celery, onions, and potatoes 5,700 25.400 31,100 1.4 Seed and truck 9,500 7,900 17,400 2.3 Tules 1,200 6,200 7,400 9.6 Brush.willows, pasture etc. 4,200 I6AO0 20,600 2.3 Idle land below elev.58US.G5 6,100 21,200 26,300 1.8 Evaporation from water surface • 15,600 SUMMAR 38,700 Y 54,300 4.9 Total area of Irrigated crops 103,000 218,800 321,800 2.1 Natural vegetation . • 3,300 1 1 ,500 14,800 6.1 Idle land below elev.59U.S.G.S. 6,700 23300 30,000 1.8 Water surface 15,600 38,700 54,300 4.9 Total consumptive area 128,600 292,300 420,900 2£ Average seasonal consumptive use of water in feet depth 2.6 2.6 2.6 L NOTE Data obtained from 1929 crop survey. Water surface area includes 1,100 acres of channel water surface between delta boundary and stream paging stations. Includes willows, tules, brush and oaks. CONSUMPTIVE USE OF WATER IN THE DELTA or THE SACRAMENTO AND SAN JOAQUIN RIVERS 74 DIVISION OF WATER RESOURCES In compiling the area of irrigated crops, it is assnmed that all crops planted on lands which lie below an elevation of five feet above mean sea level consnme water from the delta channels even though no artificial diversion of water with siphons or pumps is made for irriga- tion. The assumption is based upon the fact that the average water level in the delta is about 1.5 feet above mean sea level and reaches higher levels each day, and the high water table in the islands resulting therefrom affords 'an opportunity for the plants to obtain their moisture without artificial diversions. Ilowever, most of the crops in the delta are irrigated by artificial diversions. The total consumptive use of water has been estimated for the Sacramento and the San Joaquin deltas separately and for the entire delta. The line of division assumed between the Sacramento and San Joaquin deltas is based upon the source of water supply, the Sacramento Delta embracing all those lands which obtain their water supply from the Sacramento River channels -and the San Joaquin Delta all those lands which obtain their supply from the San Joaquin River channels, including its branches, the Mokelumne and Calaveras rivers, as well. This division line is shown on Plate III. Plate X, "Consumptive Use of Water in Delta of Sacramento and San Joaquin Rivers," graph- ically shows for all months of the year the consumptive use of water in the Sacramento and San Joaquin deltas separately and combined and tlie proportionate use of the total consumption by each crop and water-using agency. Crop acreages for 1929 are used in the compila- tion of this graph. The results for other years during the last 10 would be quite similar in the total use but with certain variations as to the proportionate use by different crops and other agencies. The estimated monthly consumption shown in Table 2 for each individual water use Avas plotted cumulatively on the vertical scale.* The lines on the graphs are drawn as smooth curves through the plotted points. The areas, designated by index number between the curved lines, as compared to the total area under the upper curved line of each graph give a graphical representation of the proportionate use of the total consumption by the different crops and agencies. As shown by this graph and the tabulations, the present estimated consumptive use of water in the entire delta varies from a minimum of about 800 acre-feet per day or 400 second-feet during the winter months to a maximum of about 7400 acre-feet per day or 3700 second-feet at the peak of the irrigation season, which occurs about the middle of August. The total annual consumption in 1929 by irrigated crops, compris- ing 321,800 acres, averages 2.6 feet in depth. The difference between this amount and the total seasonal use by the irrigated crops of 2.1 feet in depth is due to soil evaporation and use by weeds and similar vegetation on the cropped areas during the nongrowing or dormant season. As a coincidence, the total annual consumption for the gross area of 488,600 acres and the total seasonal consumption for the total consum])tive area of 420,900 acres (see Plate X) also averages 2.6 feet in depth. It is of particular interest to note the large amount of * In plotting and tabulating the consumption and consumptive areas on Plate X, certain items in Table 2 were combined. The area shown for index No. 11 includes 9500 acres of pasture. 1800 acres of brush and oaks, 3700 acres of weeds and 5600 acres of willows, totaling- 20,600 acres. Under the summary in the tabulation, the area of pasture is included with other irrigated crops ; brush and oaks with tules and willows as natural vegetation ; and weeds with the idle land below elevation 5.0. SACRAMENTO DELTA 2000 - 1 1 1 1 — 1 — I — — 1 — 1 — — r — i — T ■ 1 I 1 - - A /^ F^ \ - - rtS^ te k^ \ ' . /. ^ ' — -^ $^^ \ \ - ■ m ---~®^ ■pZ^ — =^ \^ - ^ ^ ^^ 1 1 1 1 ® 1 1 1 1 ""~i ' ^ COMBINED SACRAMENTO AND SAN JOAQUIN DELTAS 8000 I — I — I — I — \ — rn — 1 — ' — I — I 1 I I I — I — 1 — I — I — r~ Jan. Feb Mar. Apr. May June July Aug. Sept. Oct Nov. Dec. 1929 "I 5000 (—1—1 — I — r SAN JOAQUIN DELTA 4000 Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 1929 Jan. Feb. Mar. Apr. May June July Au|. Sept. Oct. Nov. Dec. 1929 LEGEND 80995 — p. Index number Area delta Seasonal Crops or classification consumptive use of water in feet depth Sacramento San Joaquin Combined 1 Grain and ha^ 6,100 63,900 70,000 1.7 2 Aspara|ui 29,1 00 33,400 62,: 00 2.7 3 Alfalfa 8,600 15,900 24,500 3.2 4 Beans 18,200 14,300 32,500 IJ S Beets 7,300 11.000 18,300 2 3 6 Corn 5,400 35,600 4r,ooo 2.4 7 Fruit 12,600 2,400 15,000 2.3 8 Celery, onions, and potatoes 5,700 25,400 31,100 1.4 9 Seed and truck 9,500 7,900 17,400 2.3 10 Tules 1,200 6,200 7,400 9.6 II Rrush.wlllows. pasture etc. 4,200 16A00 20*00 2.3 12 Idle land belo«elev.5«USfiS S.IOO 21,200 26,300 1.8 13 • 15,600 38,700 54,300 4.9 SUMMARY Total area of Irrigated cftjps 103,000 218,800 321,800 2.1 natural vegetation - . 3.300 1 1 ,500 14,800 6.1 Idle land below elev.5!U.SG.S. 6,700 23300 30.000 1.8 Water surface 15,600 38,700 54.300 A.9 Total consumptive area 128,600 292.300 420,900 2£ Average seasonal consumptive use of water in feet depth 2.6 2.6 2.6 NOTE Data obtained from 1929 crop survey. * Water surface area includes 1,100 acres of channel water surface between delta boundary and stream paging stations. *• Includes willows, tules, brush and oaks. CONSUMPTIVE USE OF WATER IN THE DELTA OF THE SACRAMENTO AND SAN JOAQUIN RIVERS < r i^ VARIATION AXD CONTROL OF SALINITY 75 Avater used by native vegetation, especially by tiiles and cat-tails wliich are estimated to consume 9.6 feet in depth annually or nearly three times as much as alfalfa and nearly four times as much as the average for all crops grown in the delta. Evaporation from open water is also relativeh' large, with an estimated amount of nearly five feet in depth per annum, or about twice the amount used by the crops. By comparing these amounts of consumptive use with the stream flow into the delta, it will be noted that there have been several months in several years since 1919 in which the flow into the delta was insuffi- cient to take care of the consumptive demands therein. The comparison of flow with consumptive use is graphically shown on Plates V and VI. With a maximum monthly consumptive use in August of about 221,000 acre-feet and an average for July and August of 212,000 acre-feet, there have been shortages in these two months in 1920, 1924, and 1926, and a shortage in one month in 1928 and most of one month in 1929. In 1924, there was also a shortage in the supply meeting the demand in the month of June. In these years in which shortages have occurred in the supply meeting the consumptive demand in the delta, the greater inva- sions of salinity into the delta have occurred. The largest monthly shortage which occurred during the ten-year period 1920 to 1929 was in August, 1920, when it amounted to 151,000 acre-feet or about 2500 second-feet average daily flow. The shortage during the two months of July and August in 1924 amounted to an average of 121,000 acre-feet a month, or at the average daily rate of about 2000 second-feet. On the other hand, in years such as 1921 to 1923. inclusive, and again in 1925 and 1927, when there was no shortage in the water supply entering the delta meeting the demand, the maximum extent of saline invasion to a degree of 100 parts or more of chlorine per 100,000 parts of water was relatively small, affecting less than 5 per cent of the delta area. The significance of these relations will be more fully discussed in Chap- ter III. Tides — The tidal records gathered in connection with this investigation represent the first attempt which has ever been made to obtain anything like complete tidal information in the bay and delta channels. Prior to this investigation there have been a few scattered observations made usually for short intervals only. Some of these were made by the United States Coast and Geodetic Survey and others by the United States Army Engineers, the State and private agencies. Never before has a compre- hensive system of automatic tide gages giving continuous records of tidal stage been connected together by precise level lines so that the relative elevation of the water surface at the same time and at different points in the bay and in the delta channels might be ascertained. The records obtained, therefore, are of great value, giving definite information for the first time as to the action of the tides, which is a most important factor affecting salinity conditions. A great deal of data could be compiled from automatic tide gage records. For the purpose of this investigation, however, there have been compiled only those elements which are chiefly important to this study. Table 4 summarizes the location and period of record for all of the automatic tide gages from which records have been obtained and used in this investigation. There are also shown the owner of the tide gage and the elevations of the zero of the tide gage staff referred to mean sea 76 DIVISION OF WATER RESOURCES < u O < O u Q H O < o H < o D OS o u u a: b O Q O u a< Q Z <; z o < O O CO > (^ en**- ■ ■•-• iO C^ C< CO CO I I i J I I J I 3 3 C3 1-5 3 a < O o o a i_ > .c CJ o o ^- — — a» w J2 o ■* . CJ ??co . Oi ^ s a . o a 5 o — -^ — — -^ o o — a a D. g2 = "3 31-a OC4 08 « 2 « o. < 3 . 3 O w O W if X O) « (- a> o^o c . _ .2 a:. 2 (5 ia I 3 I OT O 60 h> en k< a> oj cj ° E '5 "-"5) ; c^ c ■ >!^ >, a_ a fc, O fc- Q 3 CZ3 CO in OJ « '5 > o O O) o GJ o q^ C.S H fe =.= « a e "< a O t, fc, c t- U"*-"^.2a3'* CO b. I- V 3 o , pppQ p c c WW a a << coco ^ = « a e"° oico g ppS IK >>« ^ ^ ^ Qj w aj *j i^ -»* ' o ^ o o -^ o ,.> a.S _ e £ O) O 0^ o 0^ a> 5 S.5 = B C WWW a H a »- k. fc. <->;-!; cooiai I o O 2cc O o o c c o o I I i5 Q CD >^ = 5 2 = "? •^ o g c _ ♦> -*^ CQ k. *^ (U — ' (/> oa o o to GO C CQ »-■ -^ ■2S "5 00 "1 Q- O « I- JS " 5 S — '^ C 58 a fl) >> aCO § V <= g w g-o'S CO a « pa &cg S..S It Oh a S&< OS 2(S 3 o « 3 CO.? cO 92 I a— - , a ■" eg 5| If JO II ^ ^ ft 0= Sir-be -g - --- ra "■ « C V 3 Bca-c .2 b" OO HE •is.s OO - c3 « s oj 3 rt , .a aco-M<: >.^' k-0_N- «^ -ado a ,.2 " a CQ— ° C raw. SRO « S ^OCDK C>S_W o = 8.2-§|^a-5 5j= I 1 ■•3 2 = S CO ^ «o 22 w « .5 few. " « !s 5 c« g aj3 CQ o 53 S'3 O.S'S5'3-C E B OS o'c See OOOt)5PWOO &V V -S .2 a. M:2 B W .H CQ OQ a 3 ^ 1 " 3 a eg B •5 s ii o o 5 c >i.2.= -S ki S^ « OS 3 o c^OO><03aQa>A. J M o O M-O tn V a; .^. o J3 c a H VARIATION AND CONTROL OF SALINITY 77 I I + ij J o + I 1 + rt . ?» -a CS o -a o> ■•3 -a*^ C o Oa> OOO J5 *»C-J go? •g C5 -en '- >. iD 05 40 - ?> ^^ C^ =°S 1^ L^ o 0) « s P5 ^ bo a c °a (5 > (3 5^ s c a _ 1_ 1 e« , K ! u > en 1 ^ 1 c3 c^ 1 p ! -^ ! =3 ' ' 1- O ' ' paj ' ;.s^ ; ■« o ■ \oS • .CO ' , a; c , ; a.^ ; , OTCO . ; oc«" ; ; "-^ I 1 0) & 1 M. i-a- . . ''Z o ' ;ao ; ;22 j ■ -^ a>:H C t- bO 3 O O CO ^ o em co.S O g S =■ ^m o o a > § o c'C -J -i aj .OS o cS? _ 32.2 rs "c c »i o ■" 22 ^ C J ■ g aj a a n a o W z n o a mS C9 a o •ia T3 C o &i a fl rt 3 D. " « 0.2 a m >., C5 O c OJ o O 0) bc 3 & 3^ •— w -** C fc- W3 . t 3 C ,.o o- ■^ &■« o" to ^ k- rt .M L- (l^ OJ H-aj3 3 -O g 3 ja U •" O o_.iii » £5 a ° ^m " -H a a "" •►^ o ^ 3 o t. i •T3 d 1(5 O sa t9 aa dd a =« CO s> a . C8 3 r>j bo-S ■■^cz5 "^-' a.„-£o ^ r-i 3 aj c3 • dj , bO IJ ' -a 4J -s M a) m -^=„ o-^ia ■<** t^ la *-. _ cc **-* 5 a; £ o M i5 M c3 "- ~ flj 3 _. C3 aJ O .2 § "« . o a) > N 2 *— --^ aj - 3 ^ ■■ CJ o2 60 c :2^_o-cW.2 ^-r -*^ o- >> c8 3c3n!r2'-"t35-X,— 'tj-' g=-s £.23 a a^-.F^ 5? 35 rj o &-H a c J o'- '-S-3 C 53 aT o 3_2-2 = in o S5 ~s c 2 t; £.i= 78 DIVISION OF WATER RESOURCES ffl < •o u o i> M •0 a E • o u a; o H <: Q JS t •n o 0) r, ^ c! o T3 -a CO d CO 0:2 CZ -t^ 3-T3 a- ■3 & i3 o a ^i Oi OS O) 05 OS OS OS OS OS OS OS OS OS OS OS OS CO OS O o « as o o ooooooooooooooco '"' Oi Oi OOOOOOOOOCTiOicrsOOOO ■ «■ c a"-!" « rt* i-S "I yi 3 O 3-_ .. -- „ -_ „-.---;., — -- C3 C3 W WJ ;^ssHi5:?. co"*cc(rOfO'^co-^'*-*'"*'-*'^'^'»rcC'^cC'^ C^l tr: ■^ ^ --< (N ■^C^OOOMOOO ^H ^H ^H O O O *^ CM 010 »oooor-*or^■ -^ u^ M I M I I I 10 10 ^ +++ CMlClOrHt'-O^'^ *0 ''J* ^P '^ CO "^ ^J* '^ 00 :a, go \ 22 n S5 C — I M -3 C H PhcqQ «'5 Cq CM ^ '-' I I I iTT (MCMCMCMC^C<»COCO«CO OOOOOO*— '»— '•^•-t iO'ccO'-Hr^'^oooOf^t^ COCOCO-^COOOC^CMC^W I I I I I I M I I co»-i'Mj.dO03O.3VoV ^ ^ ta~i V n 3 ^^ ^-« PMPL,PH(i,aiOOHa > > > oooo > o o o o o o o o oooo ^ ^ ^ >^ o* -4J o o o o o o o -«J -4^ .t^ -t^ .t^ .»A -«^ OS OS CI Oi C^ C-1 C^ C-l OS OS OS OS 1— * T-H .— 1 1— ( OS OS OS OS OS OS OS OS OS C■ »0 t~- 1— t O C^l C^3 CO CO f>\ C^ CO iM C^l CI CO CO + ++++ + O O OSfMOO C^ C^l »-i o o I 111 + OS r^c^toio^iMeo T TTTTTT+ + o o ■<*< o ^"^ -^ lO o + OS CO O t^ OS -^ o CO -^ "^ CO CO ■^ ^ > o a b( o C3 CO bO 3 _o O) « M .2 ^ "'.5 g.>> a OH Ph&: > J3-2 MOT- T3^0 m ■^ c « «i3 " m a. ^ m (U c3 --^^ B o. o 03 o -a bO 80 DIVISION OF WATER RESOURCES level (U.S.G.S. datum). These tide g:ages have l?een located at strategric points covering the entire San Francisco Bay tidal basin from the Golden Gate to the npj)er limits of the delta. The period of record is not of the same length at all stations. There were twelve automatic gages operating at the time the investigation started in the summer of 1929, comprising the basic gage at Presidio of the United States Coast and Geodetic Survey, one at ]\Iare Island Navy Yard, four in the delta maintained by the United States Army Engineers, four in the delta maintained by the State, and two others in the delta maintained by private interests. Five new tide gages were installed by the State in the delta and upper bay in the summer of 1929. At the same time, new and more suitable tide gage recorders were installed al the four stations already operated by the State. These were folloAved in the succeeding winter by installation by the State of five additional gages at lower bay points and later, in the succeeding spring and sununer of 1930, by eleven additional gages installed by the United States Army Engineers in their coo))erative investigations. Thus, during a sub- stantial part of 1930, 33 automatic tide gages were in operation. All of these gages have been referred to a connnon datum (U.S.G.S. datum) by ]irecise level lines run by the Ignited States Geological Survey in cooperation with the State. The connecting level ties to the individual gages were run by the State and the United States Army Engineers. Table 5 summarizes the maximum, minimum and mean elevations of high and low tides, mean half tide, and tlie maximum, minimum and mean range of the tide for all of the tide gage stations in the bay and delta for w^hich records are available. The elevations .shown are all referred to mean sea level (U.S.G.S. datum). The period of recoi-d from which the data were com]uled is also shown. The height of mean tide (ap]n-oximately the same as half tide) varies from day to day through the season. This is shown on Plate XI. "Mean Daily Tide Elevations in San Francisco Bay and Delta of Sacra- mento River," and Plate XII, "Mean Daily Tide Elevations in San Francisco Bay and Delta of San -Joaquin River." On these plates the elevation of half tide is plotted for each day during the season of 1929 from July to December, at which time the first winter freshets occurred. There is a marked similarity in the general slia])e of the curves for both bay and river channels. The elevation of half tide rises and falls at each point in an almost exactly similar and i)arallel way. A rise in watei' level resulting from increases in stream floAv in the fall is shown at upstream stations such as Sacramento, but the variations in mean water level from day to day continue to follow the variations at stations down- stream and in the bay. These graphs also show the gradual increase in elevation of mean water level from the bay upstream. Plate XIII, "Height of Mean Daily Tide Above Mean Daily Tide at Presidio in San Francisco Ba}' and Delta of Sacramento River," and Plate XIV, "Height of Mean Daily Tide Above Mean Daily Tide at Presidio in Delta of San Joaquin River," show the height of mean water level (half tide) at points in the bay and delta above the mean water level (half tide) at the Presidio. The tidal variations at the Presidio, wiiich may be considered to represent the basic tidal fluctuation of the entire San Francisco Bay tidal basin, are simulated by all of the other tide gage stations above in the bay and delta VARIATION AND CONTROL OF SALINITY 81 PLATE XI »^nrM — O — '-' — <-> I Elevation in feet U.S.GS. Datum NOTE Mean daily tide elevations are computed as the mean of the elevations of hi^h-hi|h,low-hi|h h'4h-!ow and the ave'age of the two low-lov. tides occurring during each "-'dal c_yc!e MEAN DAILY TIDE ELEVATIONS IN SAN FRANCISCO BAY AND DELTA or SACRAMENTO RIVER -80995 82 DIVISION OP WATER RESOURCES PLATE XII ''III'''' Olf^ — O fM — OI o 0) o <_> O E Q. CO 3 MO < 3 Mean daily tide elevations are computed as the mean of the elevations of high-hi^h. low-high hi^h-low and the average of the two low-low tides occurring during each tidal cycik MEAN DAILY TIDE ELEVATIONS IN SAN FRANCISCO BAY AND DELTA OF SAN JOAQUIN RIVER r VARIATION AND CONTROL OF SALINITY 83 PLATE XIII Difference in elevation in feet of mean daily Tide at station and at Presidio NOTE Mean daily tide elevations are computed as the mean of the elevations of hi^h-high, low-high high- low and the average of the two low-low tides occurring during each tidal c_ycre. HEIGHT OF MEAN DAILY TIDE ABOVE MEAN DAILY TIDE AT PRESIDIO IN SAN FRANCISCO BAY AND DELTA OF SACRAMENTO RIVER 84 DIVISION OP WATER RESOURCES PLATE XIV P" '^ ■^' ^. ^N > \ 9 a o I $ UJ Z ^P^5P £ o o UJ .a o *- o o CD Xi E 0; *- a. 0) ft < 3 Difference in elevation in feet of mean daily tide at station and at Presidio NOTE Mean daily tide elevations are computed as the mean of the elevations of high-tii'ghjow-hi^h high- low and the average of the two low-low tides occurring during each tidal cycle. HEIGHT OF MEAN DAILY TIDE above: MEAN DAILY TIDE AT PRESIDIO IN DELTA OF SAN JOAQUIN RIVER VARIATION AND CONTROL OF SALINITY 85 channels. Plotting the height of mean tide level for the upper stations above the level of mean tide at the Presidio, therefore, has the effect of eliminating the primary tidal variation, which is approximately paral- leled by the variations from day to day at all points in the tidal basin. Although there are variations in the difference in elevation from day to day, the graph shows that the general water level in the delta channels gradually lowered during the 1929 season from about July to November. This is shown by all of the downstream stations such as Walnut Grove, Three Mile Slough, Rio Vista, Georgiana Slough, Antioch and Collins- ville. The upper stations, Mossdale, New Hope Bridge and Sacramento, show the effect of increased stream flow in the fall months. The fact that the water level in the delta channels fell during the summer and autumn of 1929 appears to indicate that the basin formed by the delta channels may be considered to be similar to a storage reservoir. The water level in this storage reservoir averages one to two feet or more above mean sea level during the period of low stream flow, although it fluctuates up and down with the tide several times daily. The gradual lowering of mean daily water level in the late summer and early fall months of 1929 appears to be partly due to the fact that there was an excess of consumption of water in the delta over and above the stream inflow. This would not entirely explain the occurrence, how- ever, because the mean water level continued to lower after the supply coming into the delta was sufficient to take care of the consumptive demands. Other factors, including, especially, the variation in the tidal flow at the Golden Gate and into and out of the delta tidal basin, and, possibly to some extent, the progressive change in relative salinity and specific gravity of the waters in the upper bay and delta, probably had an effect of equal or even greater importance upon this change in average water level in the delta. Studies of records for other years would be necessary before a definite conclusion could be made as to this situation. The tabulations and graphs previously presented show a gradual increase in the elevation of the mean water levels for various tidal phases with greater distance from the Golden Gate. It may also be noted that the mean and maximum ranges of the tide gradually decrease for points farther upstream. These relations are more clearly shown by the graphs on Plate XV, "Tidal Reference Planes in San Francisco Bay and Delta of Sacramento and San Joaquin Rivers." On this graph, the data in Table 5 are plotted for each station witli reference to its distance from the Golden Gate. The points for each phase of the tide have been joined by smooth lines. There results a graphic illustration of the more important tidal reference planes of particular value in this study. These reference planes are shown with separate diagrams, one extending from the Presidio througli San Pablo and Suisun bays up the Sacramento River, a second up the San Joaquin Rii^er from the confluence of the two rivers, and a third extending from the Presidio through South San Francisco Bay to its southerly end. The graphs show the relative elevation of the water in all parts of the bay for the minimum and mean low tides, for mean half tide and for the mean and maximum high tides. The relative magnitude of the mean and maximum ranges of the tide at various points in the bay and delta can also be clearly pictured. The 86 DIVISION OF WATER RESOURCES data for the sections of the tidal basin along the Sacramento and San Joaqnin rivers are representative of the low flow conditions of these streams. Table 5 shows the period of record which was used for each station in compiling the mean, minimum and maximum tidal elevations .sliown. For the river stations, this period generally included August to November, 1929. With a large flow in the rivers, the water levels at all stages of the tide would tend to be at a considerably higher eleva- tion tlian those shown. The collection and compilation of the tidal data have been a most essential part of the present investigation. These data have been used in evolving the relation between tidal action and salinity, which is pre- sented in Chapter IV. PLATE XV SACRAMENTO RIVER E ■D ■♦— (O -a to CO «..?!i'.?- miyn. ^ L.^j__ 1 1 1 ] 1 i-H^. i 1 ' 1 1 ' 1 1 1 T __ ^. «- 1 1 i=-^=^ Jl 'Mean hrj^Mtfle,^ . ^ A [ — 1 . 1 • * ^"' 1 1 , 7^ — ii-^-^: ! ] ' ] T Mean low tide —jr* r r^- 1 Mmimumiovj.?;^?-"' 1 1 ealevei-'"" ...i lt----ir- .4. — -^^ — ,;^^ :i-^T ...j ti ]■■ 1 ^' 1 ? {■•■ ■■; !i: kOX. 1 '11 ...1 ...i.i 1 10 Distance 20 30 40 50 60 in miles from the Golden Gate ). -— - — /~, i A c a ,1 M E >J T I i S ■^ Sonoma C Beacon N?2'r 'setS^^^,^^^^'^^*'^'^:^:!!:^*^''^''^ .e::*Po,nt Orient '''VallanJ Slough COST;! ; ^ E.CCI-D ^-^ i^Mossdale »£ ,,-'"' |SJ"RR.Bric){i ■" :0 A (J u I N V- S. I ! / LOCATION MAP A Automatic Tide Gage Station SCALE OF MILES 70 80 90 SAN JOAQUIN RIVER -6 110 6 ii T3 4 Cj 60 70 eO 90 100 110 Distance in miles from the Golden Gate NOTE: Compiled f roin .automatic tide ^age records obtained during 1929 and 1930 The fidal levels for the Sacramento and San Joaquin river chan- nels are representative of low stream flow con- ditions in the summer and fall months. TIDAL REFERENCE PLANES IN SAN FRANCISCO BAY AND DELTA OF SACRAMENTO AND SAN JOAQUIN RIVERS I«rt- T 1 I a '♦■^^ (! t- ~\' i I- VARIATION AND CONTROL OF SALINITY 87 CHAPTER III RELATION OF STREAM FLOW INTO DELTA TO SALINITY One of the two basic factors governing salinity conditions in the bay and delta channels is the stream flow of tbe Sacramento and San Joaquin rivers into the delta. The variation of salinity and extent of saline invasion and retreat are related generally to the total amount and the monthly distribution of seasonal stream flow, but are more particularly related directly to the actual rate of flow as it varies in amount from day to day during any season. Evidence of the direct effect of stream flow entering the delta upon salinity conditions in the upper bay and delta channels is shown by the records of salinity and stream flow delineated on Plates V and VI. An exhaustive analysis has been made of the records of stream flow and salinity to determine, if possible, their relation. Relation of Total Seasonal Stream Flow into Delta to Salinity. It appears from a study of the records of stream flow and salinity during the period 1920 to 1929 that there is a general relation existing between the total amount of seasonal run-off into the delta and the extent of saline invasion and retreat. It has been previously pointed out that the maximum extent of saline invasion into the delta during this ten-year period occurred during the summer of 1924 following the driest season, 1923-24, of the period 1920 to 1929. The invasions next in extent occurred in 1920 and 1926 following subnormal run-off seasons. It appears that the drier the season or the smaller the total seasonal stream flow entering the delta, the greater has been the extent of saline invasion. Furthermore, the records show that the extent of retreat of salinity is also related to the total seasonal stream flow. The wetter the season and the greater the total seasonal stream flow, the farther downstream has saline water been displaced by fresh water. Maximum Salinity During Season — The maximum extent of saline invasion during the season is shown directly by the maximum observed salinity for the season at the various points in the delta and upper bay channels. These maximum values of observed salinity (in the surface zone after high tide) at the more important observation stations are given in Table 6 for the period 1920-1929. In a parallel column of this table is shown also the total seasonal stream flow into the delta, expressed as a percentage of the 58-year mean (1871 to 1929). The values of maximum salinity are shown for the actual observations (samples taken in the surface zone usually after high tide) and also for the estimated mean salinity (mean tidal cycle surface zone salinity), representing an average value of the salinity during a tidal cycle period of about 24 hours. These mean tidal cycle values of salinity have been computed from a relationship established as to variation of salinity with tidal stage, which is described in Chapter IV. 88 DIVISION OF WATER RESOURCES Z o CO <: M O z a o. o o o o ■»» o a u £ o, >> o 03 a m o a a T3 "a J O P4 a o Ph M CO m Q o a, 1'» o a o » 1«>. p^ CO *0 C*5 '^ ^^ ^J* ^^ O CO O 1"» 1-1 :a^ o «> 13 t3 - O m o O w lis ^4 r^ ^ ^ c2! 0000 M CO ^^00 CC 00 OS 05 gooo 000000 o> Oi-^ oi ^^ r- U5 O kO O*-" »-' 0000 OJCO ^ t- «0C0 ^ CO O »/300 t^ •— < r^ to J^ CO •*}• "^ 0000 u^ ^ ^ cr> 00 lO 50 CO 00000 o ^^ 10 ^« Oi "to t- t-^ s? 0000 ciao ^*co O 00 00 00 > o s 3 ja 8 a 1 "» S S d 1%, O 00 O B O CO o ko o hO m t'^ 10 1-" -^ ^« .-. c^ »c c^ U5 CO 1-^ t^o 'hoo a»kQ ^HCOOOCONOO tO*0»OOiCOiOOU50 CO-^C^O^t— Ot-CD'-'OS CO CD .-< -^ — . .-H If O 50 O " *9HO'^'^(MOOiOtOO t^«D'»»''^OcO^^»C<— • -^ " QO ^ »0 -^ CO CO -^ «oc^co^oo — oeoMu^ ^^•eocoooot^icoseo CO r^ ■««< ^ CO o * COOOOou^cOOOliOO ^c4 ■^^tOOSOOOOOOSOSOS COOOOkA^COiOOacOC^ O-^C^C^TfiOcOt^OOOJ I 1 I I I 1 I I I I OsO'-^C^CO'^iCtOt^OO 03 03 O^ Oi 03 O) O^ 0> 03 ^ 0'-^c^eo^»oeot~»oooi 1 I I I 1 i 1 I I I OSO'-«C^CO^'»OCDt^OO O) OS O^ 03 Od 03 OS OS 0> OS •a a i C J, 10 a> eg fl rst: o 5 5 «. CQ fe C fc !> S £ 3 '^ aiS| 5 O 4> « ££SW VARIATION AND CONTROL OP SALINITY 89 PLATE XVI L. V -*- (0 1800 1600 a. o o o o o l_ a. ^ .- « _o ^ o ^ t « c ^ 1400 E 1200 1000 i= -s 800 o c ■a 600 ~ 400 to E E x 200 20 40 60 80 100 120 140 Seasonal stream flow in per cent df SByezr mean (I00%= 31346,000 acrft) LEGEND A Three Mile Slough O Rio Vista X Jersey a Emmaton © Antioch B Collinsville 0. & A. Ferry Bay Point Bulls Head Pbint Point Davis Point Orient RELATION OF SEASONAL STREAM FLOW INTO DELTA TO MAXIMUM SALINITY DURING SEASON 90 DIVISION OF WATER RESOURCES The data in Table 6 have been plotted and pfraphieally shown on Plate XVI, ' ' Relation of Seasonal Stream Flow into Delta to Maximum Salinity During Season." The mean tidal cycle values of maximum salinity (in the surface zone) for the season at the several repre- sentative stations have been plotted against the total seasonal stream flow expressed in per cent of the 58-year mean for each season of record. Smooth curves have been drawn for each station averaging the plotted points. It Avill be noted that these curves depart considerably from the actual points in most of the years, thus indicating that no exact relation, uninfluenced by other conditions, exists between the maximum salinity for the season and the total seasonal stream flow into the delta. However, an approximate general relation of interest and value is indicated, that, in the upper bay and delta channels, the maximum seasonal salinity at any point and the extent of saline invasion is greater, the smaller the total amount of seasonal stream flow into the delta. This relation is more pronounced for points pro- gressively further upstream. Only two of the seasons, 1920-21 and 1926-27 of the ten-year period, 1920 to 1929, had a normal amount of stream flow as compared to the 58-year mean. In general the minimum values of maximum seasonal salinity during the entire ten-year period occurred at all stations in the years 1921 and 1927, when the total seasonal stream flow was normal. There are exceptions, however, to be noted, especially in 1922, 1923 and 1925 when the maximum salinities at points in the lower delta Avere about the same as in the normal years of 1921 and 1927. Therefore, in so far as stream flow is a factor in the extent of saline invasion, it is evident that other elements must be taken into account in addition to the total amount of seasonal stream flow. These other elements arc the monthly and daily distribution of seasonal stream flow, which vary considerably from year to year and explain the wide varia- tions between the average curves and the actual plotted points shown on Plate XVI. That the relation between maximum salinity reached during any season and the total seasonal stream flow is approximate and variable simply means, first, that the distribution of the stream flow during the season is not similar from year to year, and, second, especially, that the portion of tlie total seasonal flow oeeui'ring during the summer months bears only a general relation each season to the total seasonal stream flow. The curves (Plate XVT) should therefore be considered as showing only general and ajiproximate relations. The general relation shown is of chief interest in that it furnishes an approximate basis for estimating what the maximum salinity con- ditions will be in the future and also what they may have been in past years before any records were available. It is generally possible prior to the summer period of saline invasion to obtain a fairly close estimate of the total seasonal stream flow. Accurate surveys are now being made by the State of the depth and water content of snow in the mountains so that, in April or May, rough ])redictions can be made of the remaining portion of the seasonal stream flow from which, with the previously measured flow, the total amounts for tlie season can be estimated. With this estimated total seasonal stream floAv available and the approximate general relations shown on Plate XVI, predictions can VARIATION AND CONTROL OF SALINITY 91 be made of the maximum salinities which are likely to occur in the followino; summer. The relations shown are, of course, for conditions during the ten-year period 1920 to 1929, especially as to upstream irrigation and storage diversions which effect the summer stream flow into the delta. Hence, with changed conditions as to upstream diver- sions in the future, the relations shown would be somewhat altered. This also would be true, of course, in any application of the gen- eral relations shown to estimates of stream flow for early years, when conditions were certainly very different than in recent years. The summer stream flow into the delta has been decreased in the last two decades or more by upstream diversions, and hence the relative amount of summer stream flow to total seasonal stream flow is now considerably different than in early years. However, it is of interest to apply the relations of Plate XVI to the estimates of seasonal stream flow shown on Plate IX. These estimates show a 62 per cent season for 1872-1873,. 52 per cent for 1874-1875 and 60 per cent for 1876-1877. Applying these values to the curves on Plate XVI, it is indicated that there was a material amount of salinitj^ in the lower river channels in those years as far up as Three Mile Slough, with a maximum salinity at Antioch of 200 parts or more of chlorine per 100,000 parts of water. It is probable that the actual maximum salinity was considerably less than the amount indicated by the curve because of a greater summer stream flow in the period 1870 to 1880 than during the period 1920 to 1929. Kegardless of the accuracy of the actual amount of salinity indicated, it is especially interesting inasmuch as it confirms the testimony given in the Antioch suit to the fact that saline water was present in the San Joaquin River at Antioch during several years of the period from 1870 to 1880, and even as far up as Three IMile Slough during the same period. The relations also clearly evidence the fact, confirmed by the observation of inhabi- tants familar with the conditions since the early period of settlement, that the waters in Suisun Bay have always been invaded by saline water during a portion of the year. Even with a total seasonal run-off of as much as 150 to 200 per cent of the 58-year mean, it may be concluded from the relations shown on Plate XVI that the waters of Suisun Bay would become impregnated with saline water at the time of maximum invasion to an extent sufficient to make the water unquestionably unsuitable for domestic or industrial fresh-water uses and unfit even for irrigation use in most of Suisun Bay. The seasons 1911-12 and 1912-13 had an estimated seasonal stream flow of less than 50 per cent of the 58-year mean, which would indicate a saline invasion into the lower delta as far up as Three Mile Slough. This is substantiated by the records of barge travel of the California Hawaiian Sugar Refining Corporation showing the distance traveled above Crockett of 32 to 37 miles maximum or six to eleven miles above Antioch and also by some actual tests of salinity taken in 1913 and shown in Table 34. Minimum Salinity During Season — ^A similar approximate relation appears to exist between the total seasonal stream flow and the extent of retreat of salinity as evidenced by the minimum values of salinity during the season. Table 7 summarizes the data from the available 92 DIVISION OP WATER RESOURCES Z o < v> O z -2 o iS o o o o o s. n 3 pa € I a a o < CO " ;^ o z o < H z o CO < CO b O Z o H -•J "3 Q o l.-h S.S a-3 H e.2 O * 1 Pd ■s 3 J o>no>o tooceioiooo CO oa o a "'S s'-i H I -a g a.s £ ^c 0*000 OS C4 CO ex (M TT OO OOC^ CO'**' OOOO OOOO »0 "3 t* "^ OS CO U5 CO O^OO OO O 9 OS A tCH O Ud OS COC4 ■« a 3 a •a a "S "H-S a I CS C»* CN CN C^ C^ C^ C4 M ^< kO CO ^« 00 e« c5 M c^ w c^ c^ 03 O) 0& C3 ^ ^ 9 cS _ - .a ee . 0) m 3— 3 lU CO o 25 . •am g ;j C9 u o 3 — i^ii a a a 5 2££| VARIATION AND CONTROL OF SALINITY 93 records in regard to this relation, showing the seasonal stream flow in per cent of the o8-year mean, the minimum observed salinity for the season (samples taken in the surface zone usually after high tide.) and the estimated mean tidal cycle surface zone salinity corresponding to the observed salinity, for each station and year of record. Records of salinity in the bay channels were not started by the State until 1926 and the data available for the study of this relation cover only four years and five stations from Point Orient to Bay Point. Some private records of observations at Crockett were procured for the years 1923 to 1925, inclusive, and at Bulls Head Point for 1924. For the stations above Bay Point, the minimum salinity during the season was zero for the years of record. In other words, in every year during the period 1926 to 1929, the channels in the delta and all of the upper portion of Suisun Bay were filled with fresh water sometime during the winter and spring. On Plate XVII, ' ' Relation of Seasonal Stream Flow into Delta to Minimum Salinity During Season," the data in Table 7 are graphically shown, minimum mean tidal cycle surface zone salinity during the season for all years of record being plotted again.st seasonal stream flow in per cent of the 58-year mean. Smooth curves have been drawn on the diagram averaging the points plotted for each station. The curves through the points of record, especially for Point Orient and Point Davis, indicate a fairly close relation. The relations on Plate XVII show that the occurrence of a total seasonal stream flow of 70 per cent or more of the 58-year mean has resulted in fresh water extending downstream as far as Crockett or nearly to the upper end of San Pablo Bay in those years for which records are available. Salinity records are not available for other years, especially covering periods of large floods. However, the freshening effect of winter and spring flood flows on the waters of San Pablo Bay even as far down as Point Orient is shown by the available records. Thus, in 1927, which was a season of about normal stream flow, the mean salinity at Point Orient dropped to a minimum value of about 350 parts of chlorine per 100,000 parts of water, while the salinity at the upper end of San Pablo Bay at Point Davis dropped to a mean value of about 25 parts of chlorine per 100,000 parts of water. It is of interest to compare the records of barge travel of the California-Hawaiian Sugar Refining Corporation (Plate IV) with the estimated minimum seasonal salinity at Crockett as indicated by the application of estimated seasonal stream flow to the curve shown on Plate XVII. The relations on Plate XVII indicate that fresh water would occur at Crockett with a seasonal stream flow of 70 to 100 per cent or more of the 58-year mean. Plate IV shows that fresh water was obtained at Crockett for a short period of time in 1909, 1910, 1911, 1914, 1915, 1916, 1917, 1919, 1925, 1926, 1927 and 1928. In most all of these years the total seasonal stream flow ranged from 100 to 160 per cent of 58-year mean. In three of these years, it was 70 to 80 per cent and, in two of these years, less than 70 per cent of the mean. In 1926, which was a year with 50 per cent of mean stream flow, the fact that fresh water was available at Crockett is explained by large floods ' which occurred in February and April of that season. The relations I shown on Plate XVII for Crockett are supported by the barge travel I records. 94 DIVISION OP WATER RESOURCES PLATE XVII t ro Q. C3 O CD o" 8. a> c •c o 1800 1600 1400 o c io I V) t> c s « u 10 0) o 200 000 800 600 c ■ o : w ' nj a> w . •oo.: c •T3 •^ 400 03 E E 200 20 40 60 80 100 Seasonal stream flow in per cent of 58 year mean (100%" 31,346,000 acrfU LEGEND A Crockett ■ Bay Point B Bulls Head Point A Point Davis • Point Orient RELATION OF SEASONAL STREAM FLOW INTO DELTA TO MINIMUM SALINITY DURING SEASON VARIATION AND CONTROL OF SALINITY 95 The closer relation indicated between the total seasonal stream flow and minimum salinitj^ during the season than in the case of maxi- mum salinity during the season is probably due to the fact that the greater part of the total seasonal run-off occurs during the winter and spring months. It is this portion of the seasonal run-off which directly governs the maximum retreat of salinity and hence it is reasonable to expect that a closer relation would be found. It is true, undoubtedly, that the maximum salinity during the season is also partly affected by the larger portion of the total seasonal run-off occurring during the winter and spring, because of the fact that, the greater the magnitude of winter and spring flow, the greater will be the extent of retreat of salinity and hence the longer will the period of time tend to be for the salinity to advance upstream to invade points in the upper bay and delta. In other words, a large winter and spring stream flow putting fresh water in Suisun and San Pablo bays will delay the advance of saline water upstream and hence tend to decrease the extent of saline invasion in the succeeding summer period. However, the records indicate that the rate of advance of salinity upstream is dependent also upon the rapidity with which the stream flow decreases after the late spring freshets of relatively large magnitude. If a relatively large stream flow is maintained into the late spring or early summer months, the records show that it has a marked retarding effect upon the advance of salinity. Advance of Salinity — The time at which saline invasion starts at any point in the bay and delta varies to a considerable extent in different years. From a study of the records of salinity and stream flow during the period 1920 to 1929, as graphically shown on Plates V and VI, the effects of the amount and distribution of stream floAv are evident. In seasons of large stream flow, there has been a tendency for the invasion of salinitj^ to be delayed at points in the upper bay and lower delta. Thus, in a year like 1927 which followed a normal season from the standpoint of total seasonal stream flow and during which salinitj'' retreated to a greater extent than in any other year of record from 1926 to 1929, salinity did not start to advance at the mouth of the river until July 13th. In 1921, which followed a normal season of stream flow, salinity started to advance into the delta about the same date. Compared with this, in 1929. when the retreat of salinity was much smaller and the seasonal stream flow (1928-1929) was about 30 per cent of the 58-year mean, saline invasion started at the mouth of the river about June 1st. After advance of salinity had started, a storm followed by a fairly large freshet occurred after the middle of June and temporarily halted the advance which had previoush^ started but invasion started again prior to the first of July. As another com- parative example, in 1926, which followed a 50 per cent season as regards total seasonal run-off, salinity invasion started at Collinsville on June 1. No records are available in 1924, but it is probable that the advance started at the mouth of the river as early as May.* Table 8 summarizes the data from all the available records showing the relation between the total seasonal stream flow and the date * In the dry season of 1931, salinity started to advance into the delta in early April. 96 DIVISION OF WATER RESOURCES U nJ % 0^ I O (S 5 1 1 1 1 1 I I 1 1 1 Id ilO 1 tco .2 > 2 iiiiii^iii 1 1 1 ■>-» 11-3 1 '''• S l 1 1 1 1 1 ' a> 1 1 1 ^ . I .(NCO -3 i-j H 1 1 1 a III 1 c^i t^ 1 1 lO^wa ' t^ o ^ 1 1 i(M« 1 -*a ■33 . . '3 33 . 3 >-3--3< "-3 W i ; i i MID i 1 rt t~- -"f >0 00 >> C^4 CJ en 1 1 4) •-3 •o c t^cO lO iiOCCO— 'O 5 ^ CS ICO .^^^c^^ > 8 f3 33 «:3 ,33333 o -Jj ►^h:; ■•-3 I'-s'-s'-s'-^'-s -o 1 1 1 1 JJ ^ CO"^ ' C^ i^^^HCOTt*CO >* > >>>. ; >> ; >'ci?c a *s 3S i3 '33333 1 *o i^>4 '1-3 '►^l-s'^^^i-s O 1 ! € ' ' la t^W I CO lOil^^cDOO rt 1 -< .«C^ (M B O S^ i^ ;S&i?§& ^= \^ :^s.5^S Q o ; i I I I 1 1 I o»«c 1 , 1 1 , 1 .-iCS »-^ Ct V >, >, «l i 1 1 I • 1 cd Ci 03 C3 i i i i i i^"^^^ 1. ; 1 I 1 ira N « (M , 1 1 ,^ — oi — icq M e 1 I I 1 ■ CD :^ >»? >^ :2| 3 1 i ■ >* « (» ! 1 1 ! ) ! cor^tfco 1 > 1 1 ) 1 ^HC4C<)C<4 .«j (A N i N ilill 1 1 1 1 1 1 1 1 1 1 • I III!! \%ot^T^^ t r 1 1 • 1 ^ N CO-^ i ' i i i illll 1 1 1 1 I 1 < •3 PQ o VARIATION AND CONTROL OF SALINITY 97 of beginning of advance of salinity for eleven representative stations in the bay and delta. The total seasonal stream flow is shown in per cent of the 58-year mean. At the lower bay stations, the date shown for the beginning of advance of salinity has been taken as the time when the salinity at the particular station started to increase contin- uousl}' above the minimum value for the season. At the stations in the upper bay and delta, the date shoM^n is generally taken at the time when saline water of a definite degree of about 10 parts started to be present at the particular station with the salinity increasing contin- uously thereafter to higher values. The data for the upper bay and delta stations have been plotted on Plate XVIII, "Relation of Seasonal Stream Flow into Delta to Date of Beginning of Advance of Salinity. ' ' In general there is considerable discrepancy in these records, showing that there is no clear and direct relation between the total seasonal stream flow and the date at which salinity starts to advance. Dotted curved lines have been drawn on the diagram, indicating the approxi- mate trend for each station. Although the relation is only approximate, it shows a general tendenc}" of wet years, with normal or more than normal stream flow, to delay the time at which salinity starts to advance at points in the upper bay and lower delta channels. That no exact rela- tion exists is to be expected because of the fact that the exact time at which saline invasion starts at any point obviously must be affected by the monthly and daily distribution of the total seasonal stream flow and, especially, the monthly and daily stream flow during the late spring and early summer months. In other words, the rapidity with which the stream flow falls off after the floods of winter and spring is bound to affect the rate of advance of salinity upstream from the points of maxi- mum retreat and hence the date at which saline invasion starts at any point in the basin. Relation of Summer Stream Flow into Delta to Salinity. As shown by the records in Table 8 and Plate XVIII, the invasion of salinity into the lower end of the delta generally starts some time between May and July, with an average perhaps of about June 15. The period of advance of salinitj^ upstream into the delta generally continues thereafter until about the first of September, when the maximum salinities for the season generally occur on the average, based upon the records during the period 1920 to 1929. This period from the middle of June to the first of September generally embraces the period of minimum stream flow into the delta. During the same period, the main movement of saline invasion occurs throughout the upper bay and delta. In general, the period from about the middle of June to the first of September covers the entire period of advance of salinity in the delta channels above the confluence of the Sacramento and San Joaquin rivers, except in cases of "pocketed" salinity where there is little or no inflow to effect its retreat. In analyzing the records of stream flow and salinity, it appeared reasonable to assume that the stream flow into the delta during the period of advance of salinity should bear some direct relation to the maximum salinity occurring during the season at the end of the period of advance. Several trial studies were made of this relation, using different periods of the total summer flow. Based on these trial studies it was found that the summer stream flow during the period from June 15 to August 31 7—80995 98 DIVISION OP WATER RESOURCES PLATE XVni 10 February 20 10 March 20 10 April 20 May I 10 June 20 10 July 20 10 August 20 1 1 1 1 1 1 1 1 1 III 1 1 1 1 1 1 1 1 1 - - - - \ \ \ ■ 1929^, AI929 V \ ■1926 \ \ AI92N ■ 1928 V - i92*X 1924 0^ \ \ 31929- \ (91929 A$\,9. V a 1926 \%Ol92K n£ xm26 \ XI926^ ^1928 ^^a.928 ^928 ^ XI9?8^ 19271 - \ ^ajg; 19295 ©'l9: ,929^^2;'= XI9 "^^ oN ^ ^ 1926V "^^ n I92S 1923^ 1923 $1925 " .^,^^ l5274 1927 • ,^ 1927 S Vv 11921 3^321 91921^ 1 1 1 19290 1 1 1 N 1 1 1 1 1 1 1 1 1 31921 o '£ o 1 .o»oo»c»«»cic 10 1 ti-t^^ — (MiON »i-a o CO CO ^'4« ^ ^H C3 Ui s a w *ts o 1 00000»d00>0»0 ^MC^c^-^'trcocc05'r> >> c^ »c eo •-< o. o S; o o 1-5 o o l_ 0*Oi«tO»COOOOift 8 C?5000ii-H<-^OOCOCOJ fcOr-ll-Hi-lOO.-Ht^l-ICO'^ V .S -5 'C o 3 -< •o a OiO"5iftOOW5iCOO -2 =3 eocoicccco'«*^4<^r^ 'C §1 ^ >> d <*A *n *« II!!! !oooo CO cs CO ^ 00 Sf° 1 1 1 1 1 1 CO 00 0> Oi i «l J *x "S I I I loooooo 1 1 1 1 en 05 ■^ 1 h- ^ t^iO ^^"^"^ •3 s (IhQ 1 I I I looooo 1 1 t 1 . C^ »-• 40 •<*< 1 I t 1 -to^cor^t^ "S i 1 I : i^li"""" 1 0000000000 OOOQOOOOOO OOTOCTh-Oi^cDuOO ■2 a o 5 CD oT 00 c^ -^ OS f ^ -^ 00 ^0'^»oeocoO!r^»^a> 10 CO coc5 c^-*oor^ r* 03 ^ .5 t^ eH a >* 0-i'NDO'^«CDt^odos OS OS ^ Oi OS OS OS ^ OS ^ iS T3 ■§■ P-, 2 o " > >> • pa « " 8 " 3 I- Q)>-5 ■«'g.s .2 o ° J3— S d cQ o M« g lis fcScQ VARIATION AND CONTROL OF SALINITY 101 PLATE XIX u in t: Q- O O o o' o 2,000 1.800 1,600 1.400 a. .5 ,1,200 o : 1,000 O •— o' C ra O .'H -^ rtJ c 1) (O •oo5 c ■o 800 600 in E ZJ E x 400 200 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 Total stream flow into delta from June 15 to Sept. I in million acre-feet LEGEND A Three Mile Slough O Rio Vista >< Jersey D Emmaton « Antioch a Collinsville aa A. Ferry Bay Point Bulls Head Point Point Davis Point Orient RELATION OF SUMMER STREAM FLOW INTO DELTA TO MAXIMUM SALINITY 102 DIVISION OF WATER RESOURCES Relation of Rate of Stream Flow into Delta to Salinity. The study of the detailed records of daily stream, flow into the delta and salinity at various points in the bay and delta channels during the period 1020 to 1929 indicates that the degree of salinity at any point in the basin is generally related to and varies with the rate of stream flow. This is well shown on Plates V and VI on which the salinity records are graphically shown directly above the graphical record of stream flow. The general relation of salinity to rate of flow and the effect of changes in rate of flow upon salinity may be.setforthmost effectively by a consideration of the records of stream flow into the delta and salinity at a particular point in a typical season. For this purpose the varia- tions and relations at 0. and A. ferry in 1929, as shown by the curves on Plate VI, afford a good illustration. In the following discussion it will be understood that the figures for salinity are expressed in parts of chlorine per 100,000 parts of water. At the beginning of the year in 1929, the salinity Avas 50 parts with a stream inflow of about 18,000 second-feet. From January 1 to January 15, the stream flow gradually dropped to about 10,000 second-feet and salinity at 0. and A. ferry rose to a little over 100 parts. The stream flow then increased to 14,000 second-feet, and the salinity immediately decreased, dropping to about 50 parts on the first of February with a flow of about 12,000 second- feet. • The stream floM^ then increased to 50,000 second-feet on about February 5 and the salinity dropped off to less than ten parts. The stream flow decreased immediately thereafter, reaching about 16,000 second-feet on February 17 and 18,000 second-feet on March 1. The salinity did not immediately increase, but by March 1, it had risen to about 50 parts again. About March 10, the flow increased to about 30,000 second-feet and the salinity immediately dropped to less than ten parts. The flow then decreased to about 20,000 second-feet and averaged about this amount from March 20 to May 20. During this period, the salinity averaged about 25 to 40 parts. On oMay 20, the stream flow dropped off, reaching 10,000 second-feet on June 1 and continued at jibout this rate for about fifteen days. P>y June 10th, salinity increased to about 100 parts. A small freshet then occurred, the stream flow increasing to a little over 20,000 second-feet. This caused a drop in salinity, but the freshet was only of short dura- tion and the stream flow immediately decreased, reaching about 6000 second-feet on July 1. The salinity again ro.se to 100 parts on July 1 and then increased rapidly with the further decrease of stream flow. Tlie stream flow reached a minimum about July 20 of about 2500 second-feet. At this tiine the salinity at 0. and A. ferry had risen to about 400 parts. The stream flow then increased gradually to about 3000 second-feet on August 1 and continued at about this rate on the average during the month of August. During this time, however, the salinity did not remain constant at 0. and A. ferry but continued to increase from about 400 parts on July 20 to a maximum of about 800 parts on September 1. During September the flow gradually increased to a little over 6000 second-feet and in October to about 7000 second-feet, remaining about this average flow until December 10. During this period the salinity at 0. and A. ferry gradually dropped to about 300 parts. A relatively large flood flow then occurred, reach- VARIATION AND CONTROL OF SALINITY 103 ing about 106,000 second-feet on December 18. This freshet resulted in saline water being removed entirely from the lower delta channels and the water became fresh at 0. and A. ferry at the peak of the freshet. The stream flow rapidly fell off, however, and by the first of the 3^ear had decreased to about 15,000 second-feet, accompanied by an increase in salinity at 0. and A. ferry to about 25 parts. The relations shown between rate of flow into the delta and salinity at 0. and A. ferry may be considered as typical of those which have occurred at all of the upper bay and delta observation stations during the period of record. Although there is no constant relation indicated between the degree of salinity and the rate of flow during all times of the 3'ear, the record clearly shows that the salinity at any particular time at a typical point usually is directly affected by a change in the rate of stream flow. An increase in stream flow at any particular time tends to decrease the salinit3^ while, on the contrary, a decrease in stream flow tends to increase the salinity. It is evident that the ques- tion as to whether an increase in stream flow effects a decrease in the salinity depends upon the degree of salinity present at the time as well as the amount of increase in flow. The effect of stream flow is also modified by the relative amount of consumption in the delta as will be more fully explained hereafter. When the salinity at 0. and A. ferry was about 100 parts on June 10, an increase in stream flow from 10,000 to 22,000 second-feet resulted in a decrease in salinity to about 10 parts, whereas, with a salinity of about 400 parts on July 20, an increase in stream flow from 2500 second-feet to 3500 second-feet did not decrease the salinity but, instead, the salinity continued to increase and advance upstream. A great multiplicity of studies have been carried out in an effort to discover any relations existing between rate of stream flow into the delta and resulting degree and variation of salinity at various points in the delta and bay. These have included analyses as to relation of rate of flow to date of beginning of advance of salinity, rate of increase and advance of salinity, rate of decrease and retreat of salinity and maxi- mum seasonal salinity. The analyses as to date of beginning of advance of salinity and rate of increase or decrease of salinity were not con- clusive. With respect to maximum seasonal salinity, trial studies were made of the relation of minimum rate of flow during the season to maximum salinity during the season, using minimum one-day, five-day and ten-day average daily rate of stream inflow. No definite rela- tions were shown by any of these trial studies. The reason why a definite relation does not exist between minimum rate of stream inflow and maximum salinity during the season appears to be evi- dent if the governing factors be carefully analyzed. Thus, consider- ing any typical point in the lower delta, the .salinity, after invasion starts, increases at a rate depending upon the rate of decrease in stream flow. When the rate of stream flow has reached a minimum for the season and starts to increase again, the increased flow usually is not sufficient at first to prevent a continued advance of salinity, especially at points in the lower delta and upper baj'' channels, and the salinity continues to increase generally and reaches a maximum for the season only at a time when the stream flow has increased to a sufficient extent above the minimum flow for the season to start a decrease of salinity ]04 DIVISION OP WATER RESOURCES for the degree which has been reached at any typical point by that time. It is evident, therefore, that the maximum salinity reached during the season at any point is dependent upon the amount and variation of stream flow during the entire period of advance of salinity, that is, the period between the time when salinity starts to advance and the time at which the maximum salinity for the season is reached. There is no reason to assume that the minimum stream floAv during the season is the direct cause of the maximum salinity during the season or that they are directly related. The conditions of salinity and flow at the time of maximum salinity are entirely different than those at the time of minimum stream flow, and their occurrence is separated usually by a considerable interval of time. As a result of these studies as to maximum seasonal salinity, it appeared that the rate of flow into the delta at the time of occurrence of maximum salinity for the season should be related most closely to the maximum salinity reached at various points in the delta and upper bay. Studies were, therefore, made of this relation, based upon all the avail- able records during the period 1920 to 1929. Table 10 summarizes the records of maximum salinity during the season and the rate of stream flow into the delta at the time of occurrence of maximum salinity. The data are compiled from the records for eleven typical stations from Point Orient to Rio Vista. The maximum salinities in the tabulation have been estimated from the observed maximum salinities (from samples taken in the surface zone usually after high tide) as the mean values during the tidal cycle period corresponding to the observer's sample. The basis of these estimates of mean tidal cycle salinity is presented in Chapter IV. Mean tidal cycle salinity is used in place of the observed salinity taken from samples after high tide becau& the rate of flow is the mean daily rate and should be related to the mean salinity for the day, which is approximately the period of a tidal cj^cle. The relation is more exact because of the fact that there is considerable variation between the mean salinity for a tidal cycle and the maximum salinity after high tide depending upon the range of the tide occurring at the particular lime the sample was taken. The detailed relations, on the tidal variations of salinity are discussed in Chapter IV. The data in Table 10 are presented in graphical form on Plate XX, "Relation of Rate of Stream Flow into Delta to i\Iaximumj Salinity. ' ' Smooth curves have been drawn averaging the plotted points' for each station. For the most part the points conform fairlyj closely with the average curves, thus indicating a fairly close relatio between the maximum salinity for the season and the rate of streamj flow into the delta at the time of occurrence of maximum salinity. Th reason that the plotted points do not more closely conform to the average curves drawn for each .station may be explained by the fact that ther is a considerable variation in the actual time of occurrence of maximu salinity from year to year at each station and hence some material' difference in the amount of water being consumed in the delta at the time of occurrence of maximum salinity in different years. The average relations shown should be considered to be for average conditions as to consumption in the delta in early September, which is about the average time of occurrence of maximum salinity for the several years of record at the typical stations considered. For any other time in the year the J VARIATION AND CONTROL OF SALINITY 105 z o < CO O z D Q >! H CO X < o CO D 2 S CO o o [1, s H Hi Q O H Z O < o: H CO b O H < on tu O Z o H <: u a: >> m "3 3 « 03 Q a '3 Q - 3 >> .§•3 S=2 ceo § o 0- 3 >> ■►3:2 « e8 0.3-2 -ts o g 0) 0- 3 >i 0-= oooooooooo oooooooooo oooooooooo oooooooooo 0.S'S 0-^ ■s| C3 c3 c^ ^ ^ ^ CO 53 S a ■3 PL< a- 3 >) 0-^ ««8 0- 3 >. 0-^ S"" 0000 Ofl CO T-< 00 CO 00 05 01 0000 0000 CO to iC CO 000000 03 CT> -^ -M f— • t* 100 lO O *-« '-< 000000 000000 t^ -^ un 00 -^ ■^^ o iCOO t"^ CO ^* ^* > o 3 >> c£ 3 o 0- 3 >, II 0.S-S -!3 og 0000 0000 000^00 00000 CO Ci :0 t^ t^ 00000 00000 ■^cn 00 — ^CD 10 CO *r3u3 CO c3 a a- 3 >. §•3 « c3 000 000 « ■* CO 00 00 ■^ CO 000000 000000 ci" -^ c4" LO »ff CO »OiO»00*OOU^O»^0 co^wc^t^ot'-co^^as CO CO »-H Tj< »-l ^H s-s ■ t- jr c CQCO a 3 >> 0-- a.s- jcqa o O^^C^CO^»OCOt— 0OC3 c^c<»c^c*icic^c> ■s.a « CS 00 00 00 CO C^'tC 000000 oo>o o 00 CO 05 Q> CO t!* C^ CO »-» 03 oooooooooo oooooooooo CO-H(MCo«oeo»oeo?D^^ o a o •s a B a 03 O CO C9 to ac o'C O 3 0-0 §.§ 06 fc^.S Hi 3*3 a O'-«C^C0^*'»'3C0l^00OS CM C-1 C^ C^ 05C3C5CS350S3iOiC305 ^f■S° .S a ® a ITS S "> o Q) a c8 li§ ^ **^ ♦* §•32 a ^ >» l£ ■s t3ta 03 H H a s hSoq 106 DIVISION OP WATER RESOURCES PLATE XX 2000 2 3 4 5 6 7 Stream flow into delta in thousand second -feet (at time of maximum salinity) LEGEND A Thr<>e Mile Slough O Rio Vista X Jersey a Emmaton O Antioch a Collinsville A 0.6iA. Ferry ■ Bay Point B Bulls Head Point A Point Davis • Point Orient RELATION OF RATE OF STREAM FLOW INTO DELTA TO MAXIMUM SALINITY VARIATION AND CONTROL OF SALINITY 107 relation shown between the rate of flow into the delta and the raaximum salinity wonld be modified by the difference in amount of consumption of water in the delta at the particular time and that on September 1. At a time when the consumption of water was greater than that on September 1, the rate of flow into the delta related to a particular degree of salinity at a particular point would be greater than that shown by the curves by an amount equal to the difference between the greater consumptive use and the use in early September. It is clear, therefore, that the relation between rate of flow into the delta and maximum salinity shown on Plate XX is not strictly applicable to any time of the season, but only for the particular time of year as of about September 1. The relation also takes no account of possible differences in magnitude of tidal flow at the time of occurrence of maxi- mum salinity in different years, which might affect the relation to some extent. With a flow of 6000 second-feet into the delta, the curves on Plate XX show that the mean tidal cycle salinity might reach maximum degrees of 360 at 0. and A. ferry, 200 at Collinsville, 150 at.Antioch, 60 at Emmaton, 40 at Jersey, 20 at Three Mile Slough, and 10 or less at Rio Vista, all in parts of chlorine per 100,000 parts of water. With a flow of 5000 second-feet, the maximum degrees of mean tidal cycle salinity in parts of chlorine per 100,000 parts of water would be : 0. and A. ferry, 500; Collinsville, 310; Antioch, 250; Emmaton, 100; Jersey, 70; Three Mile Slough, 40; Rio Vista, 10. These values of maximum salinity relative to these inflows into the delta would be for conditions of consmnptive use in the delta as of September 1. It is interesting to note that all of the curves for the stations near the mouth of the river have a trend toward the vertical at a flow of about 3000 second-feet. This is to be expected inasmuch as at the usual time, in early Septem- ber, when the maximum salinities in the lower delta have occurred in the several years of record, the consumption of water in the delta is at the rate of about 3000 second-feet, resulting in practically zero flow at the mouth of the river and affording the potential opportunity, if the same conditions continued, for salinity to increase to that of sea water. The vertical trend of the curves indicates this tendency. The relations shown are of particular interest from the standpoint of control of salinity. Inasmuch as the rates of flow were of simulta- neous occurrence with the maximum salinities reached at the various typical stations, it is evident that these flows were sufficient under the conditions obtaining at the time to prevent the further advance or increase of salinity at the particular points and for the particular degrees of salinity reached. Hence, these rates of inflow represent con- trol flows for various degrees of maximum salinity reached at these particular points at particular times of the season. A subsequent increase in flov/ resulted in a decrease of salinity and a retreat move- ment. The maximum salinities occurring during the years of record at Antioch and Collinsville near the lower end of the delta, have all been above 100 parts of chlorine per 100,000 parts of water. Therefore, the curves of relation l)etween rate of stream floAv into the delta and maxi- mum salinity must be extended to obtain an approximation of what the control flows would be for jireventing a further increase of salinity at a degree of 100 parts or less at these points. The protection of the entire 108 DIVISION OF WATER RESOURCES delta from harmful saline invasion in such a 'vvay as to make available fresh-water supplies at all times with 100 parts or less of chlorine per 100,000 parts of water would require a determination of the amount of flow required to prevent the salinity from increasing further after reaching a degree of 100 parts or less near the loAver end of the delta. By extending the curve for Antioch, the relation shows that a flow into the delta of about 7000 second-feet would prevent the salinity from increasing at Antioch above a mean degree of 100 parts for conditions as of about September 1. Although this is somewhat of an approxima- tion, the relation indicated is of considerable value as a check on the more accurate determinations of control by stream flow evolved from a consideration of tidal action as well as stream flow as presented in Chapter IV. The curves of relation for Antioch and Collinsville and the stations upstream indicate that a flow of about 7000 second-feet into the delta would afford ample protection from harmful saline invasion into the delta for conditions as of about September 1. Relation of Source and Distribution of Stream Flow into Delta to Salinity. The source and distribution of flow into the delta has an important bearing on salinity conditions therein. The greater part of the stream flow entering the delta comes from the Sacramento River. The detailed records of stream flow presented in the tabular summaries and on the graphs show the relative magnitude of the flow from the two stream systems which in combination make up the total inflow into the delta. During the summer months of July and August, for example, the flow from the San Joaquin River system during the period 1920 to 1929 has averaged but 30 per cent of the total combined flow. Thus, the delta usually must depend to the greater extent for its water supply on the flow of the Sacramento River. The portion of the total inflow of the Sacramento River entering the San Joaquin Delta comes through two interconnecting channels of limited capaeit3^ Because of the relatively small inflow usually avail- able from the San Joaquin River system, salinity conditions in the San Joaquin Delta depend to a large extent on the water supply contributed from the Sacramento River. The limitation in this chief source of supply for the San Joaquin Delta has resulted in considerably different salinitj^ conditions in the San Joaquin than in the Sacramento Delta. This is shown especially for the years 1920, 1926, and 1924, when the extent of saline invasion was much greater in the San Joaquin than in the Sacramento Delta. For example, in 1924, the channels of 54 per cent of the San Joaquin Delta were invaded by salinity to 100 parts or more, while only 30 per cent of the Sacramento Delta was similarly affected. In years of subnormal streamflow, the portion of the Sacra- mento River flow supplied to the San Joaquin Delta together with the relatively small infloAV usually available from the San Joaquin River system has not been sufficient to take care of the combined requirements of water consumption and resistance to saline invasion. Even in such years as 1929, the salinity in the channels of the San Joaquin Delta was in general considerably greater than in the Sacramento Delta at points equidistant from the mouth of the river. The records also show that salinit.v has tended to remain in the San Joaquin Delta channels, espe- ciall}' in the region of Middle and Old rivers and the upper Mokelumne VARIATION AND CONTROL OF SALINITY 109 River, for a considerable period of time after the Sacramento Delta channels have been completeh^ flushed out. In all years in which the invasion of salinity into the San Joaquin Delta did not reach a material extent, the inflow from the San Joaquin River system, during the period of low stream flow, Avas considerably larger than in the years of greater invasion. If this larger flow had not been available in these years, the salinity conditions in the San Joaquin Delta undoubtedly would have been entirely different with a greater extent of invasion in all of these years. Any future developments which would still further decrease the inflow from the San Joaquin River and its main tributaries would tend to increase the extent of saline invasion into the San Joaquin Delta. It is, therefore, important to determine the distribution of flow of the Sacramento River between the several channels into which this river branches below Sacramento and more particularly as regards the pro- portion of the total Sacramento River flow which is carried into the San Joaquin Delta by the two connecting sloughs, Georgiana and Three Mile. This has been determined by a series of measurements of the flow through the branch channels, comprising Sutter, Steamboat, Georgiana and Three Mile sloughs and of the Sacramento River below its junction with Georgiana Slough. The location of these branch channels is shown on Plate III. The first branch below Sacramento is Sutter Slough, which leaves the main stream on its right or westerly bank about opposite Courtland, or about 25 miles downstream from Sacramento. The next branch downstream is Steamboat Slough, which leaves the main channel on the right or westerly bank about two miles below Courtland. These two sloughs form a junction a few miles downstream and finally again join the main river about two miles above Rio Vista. Georgiana Slough branches off from the main river on its left or easterly bank immediately downstream from Walnut Grove, or about 32 miles below Sacramento. This is the first branch channel which connects with the San Joaquin Delta. It joins the Mokelumne River about three miles upstream from the confluence of the Mokelumne and San Joaquin rivers. Three Mile Slough forms the second and farthest downstream connect- ing channel between the Sacramento and San Joaquin rivers. It leaves the left or easterly bank of the Sacramento River about three miles downstream from Rio Vista, or about 50 miles below Sacramento. It is located about ten miles above the confluence of the Sacramento and San Joaquin rivers. Bisiribution of Flow of Sacramento River in Delta Channels — Plates XXI to XXV, inclusive, show the results of typical measurements made of the flow through the several branch channels of the Sacramento River below Sacramento. For each channel, typical stream flow measure- ments have been selected for graphical presentation covering different rates of discharge of the Sacramento River past Sacramento. Plate XXI shows typical measurements for Sutter Slough; Plate XXII for Steamboat Slough; Plate XXIII for Georgiana Slough; Plate XXIV for the Sacramento River below "Walnut Grove (below junction of upper mouth of Georgiana Slough) ; and Plate XXV for Three Mile Slough. The graphs show the character of the flow which varies in rate from time to time during a period of 24 hours with the rise and fall and the flood and ebb of the tides. Each separate measurement of flow made no DIVISION OF WATER RESOURCES PLATE XXI ID T3 C o o 0) 8 12 -_ -*l-Ga|e heignt Mean ^ge^heighT^3^0 fW- \ viean discharge 5500 second-feeT To San Francisco for tidal cycle period of 24 hrs..5Smin. from 1 :40 A.M. Jan. 7. gage height 4.4 ft. to 1235 RM. Jan.S.gage height 4.70ft. Flow of Sacramento River at Sacramento 23.600 second^feet. 8 10 12 6 8 10 12 2 8 10 12 o it' 13 to T3 _ C h- (D O o IS 16 ^— Ga^e height I : I ! I L — Me8n_gage Ji^ej^ght =10.78^- — -rnl* 13 ^ — ^12 J I L 0} K) Mean discharge 13,800 second-feet to San Francisco for tidal cycle period of 24 hrs.,21 min from 8:45 A.M.Dec.l8. gage height 10.8 ft. to 9.06 A.M. Dec.l9,gage height 10.70ft. Flow of Sacrannento Hiver at Sacramento 64,400 second-feet. lop o 2 ^- c JZ a (0 Mean discharge 240 second-feet to San Francisco for tida cycle period of 24 hrs., 50 min. from 3:20 RM.July26.gage height 2.6 ft to 410 RM. July 27, gage height 2.6ft Flow of Sacramento River at Sacramento 2.490 second-feet. MEASURED FLOW THROUGH STEAMBOAT SLOUGH AS SHOWN BY TYPICAL MEASUREMENTS THROUGHOUT COMPLETE TIDAL CYCLE PERIODS 112 DIVISION OP WATER RESOURCES PLATE XXIII 8 10 12 8 10 12 8 K)^ a: _ e^ ■P-S 9 c .0 o 1 00 Tn — 1 — I — rn — i— 1 r Dec. 15, 1929 Dec 16,1929 § 0) H- ■u c 0} fr. « ■> t -0 or tn 1- 3 rr u ^ ro c ,0 Mean dischar^ 8,800 second-ftet to San Joaquin River for tidal cycle period of 24 hrs.,50 min. from 6-00 P.M. Dec. 1 5, gage height 9.4 ft. to 6:50 P.M. Dec. 16 gage height 9.8 f[. Flow of Sacramento River at Sacramento 59,700 second-feet. (0 D O (0 JZ o CO > E Mean discharge 5,B00 second-feet Id San Joaquin River for tide cycle period of 24 hrs.,50 min. from r.50 RM. Dec. 12, gage height 6.6 ft. to 2:40 RM. Dec.l3,gage height 7.8 ft. Flow of Sacramento River at Sacramento 29,500 second-feet. 8 10 12 8 10 12 8 10 0) .9i ■4) CO T" —\ — I — I I T" July 29, 929 —T~\ — r~i — r— July 30. 929 Mean discharge 1,290 second ftet to San Joaquin River for lida cycle period of 24 hrs.,50 min. from 8:10 AM July 29. ga^e height 3.6 ft. to 9:00 A.M. July 30, gage height 3.0 ft. Flow of Sacramento River at Sacramento 2,590 second-feet. MEASURED FLOW THROUGH GEORGIANA SLOUGH AS SHOWN BY TYPICAL MEASUREMENTS THROUGHOUT COMPLETE TIDAL CYCLE PERIODS VARIATION AND CONTROL OF SALINITY 113 PLATE XXIV 10 12 o o 'o c to c to en -\ — I — r 8 10 12 July 27, 1929 f July 28. 1929 "T — i — r 8 W, ■J— 1-1 '55 (D "OO Mean discharge 330 second-feet to San Francisco for tidal cycle period of 24 hrs.,50 min. fromS'-IO P M.July 27, gage height 2.9 ft. to 9^00 PM.. July28,gage height 3.4ft. Flow of Sacramento Kiver at Sacramento 2,590 second-feet. MEASURED FLOW OF SACRAMENTO RIVER BELOW WALNUT GROVE AS SHOWN BY TYPICAL MEASUREMENTS THROUGHOUT COMPLETE TIDAL CYCLE PERIODS 8—80995 114 DIVISION OF WATER RESOURCES PLATE XXV 30 ■2^20 2 E ,0(0 1^ o CO a> -oS 10 <- c 5 3 t/7 30 0) i/Iean discharge 2500 second-feeT To San Joaquin River for tida >om 3:40 RM.July 30, gage height OOfT. to 4:40 RMJuly cycle period of 25 hrs. ,gageheighT 0.65 ft. Flow of Sacramento River at Sacramento 2.590 second"feet. £ 3 "OO (- <0 o Mean discharge 3700 second-feet to San Joaquin River for tidal cycle period of 24 hrs.,55 min. from 5.-00 P.M. Dec.l9.|age height 4.2 ft. to 5--55 RM. Dec. 20, gage height 3.5 ft. Flow of Sacramento River at Sacramento 103,600 second -feet. > I o g to CO . cz rs : '='' ■ > (O ■ o —} c ro to T0'° 12 2 4 ( > 1 } 1 12 \ \ ( 5 i 10 12 ' t < 20 10 10 20 30 1 C L 1 1 1 / ^ <. 1 1 1 1 1 1 ~^ Noon 1 k s c CQ r / s ^ .f> D ischor ge-^ ^ \ - V h_ei£lT \ ' 1.79 f r.->-- \ > - "] r pf — ^" i >^ - Gaj e heij ;ht^ \ ,/^ \ \ c - t: J 1 Jan 1 12.1930 1 ! 1 1 1 1 1 Ja Y 13, 1 1930 N >-L- 1 SI ro (£> Mean discharge second-feet for tidal cycle period of 25 hrs., 10 min. from IhOO A.M. Jan. 12, gage height 4.0 ft. to I2:|0 P.M.Jan. I3,« height 3.7ft. Flow of Sacramento River at Sacramento 23,800 second -feet. MEASURED FLOW THROUGH THREE MILE SLOUGH AS SHOWN BY TYPICAL MEASUREMENTS THROUGHOUT COMPLETE TIDAL CYCLE PERIODS VARIATION AND CONTROL OF SALINITY 115 at about hourly intervals during a tidal cycle period of about 24 to 25 hours is plotted on the g:raph. When the flow of the Sacramento River is small, there is usually a reversal of current and flow in each of these channels during flood tides. This is shown on the lower graphs of Plates XXI, XXII, XXIII, and XXIV. However, with larger flows, there is no reversal but usually a slackening of downstream velocity and flow during flood tide. For the flow conditions in the Sacramento River during the 1929 season, it was found that the net flow for a 24-liour period in all channels except Three Mile Slough was always downstream towards San Francisco or towards the San Joaquin River. The net flow for the. approximate 24-hour period is computed as an average of the variable flow during the tidal cycle period. In Three ]\Iile Slough, there is always a reversal of flow during a tidal cycle period of 24 to 25 hours regardless of the flow in the Sacra- mento River at least up to maximum flows of 100,000 second-feet past Sacramento which is the largest flow at which a measurement was taken. The measurements on Three Mile Slough indicate that the preponder- ance of net flow through Three Mle Slough is from the Sacramento to the San Joaquin River. However, three of the measurements which were made indicated a zero net flow ; that is, the net result of the tidal flow from the Sacramento to the San Joaquin and from the San Joaquin to the Sacramento River during the tidal cycle period of about 25 hours was no net transfer of water either way. In making all of these stream flow measurements, but especially those on Three Mile Slough, an effort was made to schedule the measure- ments so that they would cover all variations of tidal conditions includ- ing range and type of tide. In addition, the schedule for measurements was fixed to cover different discharges of the Sacramento River. The compiled data covering all measurements are summarized in Table 11. There are shown for each station the date of measurement, the computed net flow from each measurement and the flow of the Sacramento, San Joaquin, Cosumnes and Mokelumne rivers, and the combined flow into the delta on the date of each measurement. The figures shown in Table 11 for the flow of the Sacramento River past Sacramento, except for Three Mile Slough, comprise only the flow in the main channel and hence differ from amounts on corresponding dates in Table 37, the latter of which include the flow, if occurring, in Yolo By-Pass. Those for Three Mile Slough include the flow in the main channel and in the Yolo By-Pass as well. The dates shown in Table 11 indicate the day on which the mean time of measurements fell. The corresponding flows for the Sacramento River past Sacramento and for the San Joaquin River and its tributaries are for dates preceding the actual dates of measurement in the branch channels, differing by the esti- mated period of time required for the water to flow, at the rate pre- vailing at the time of measurement, from Sacramento to the gaging stations on the branch channels. The division of flow and its relation to the flow of the Sacramento River past Sacramento are shown for all branch channels except Three Mile Slough on Plate XXVI, "Distribution of Flow of Sac- ramento River Through Branch Channels Below Sacramento." For each slough, the computed discharges for each measurement are plotted 116 DIVISION OP WATER RESOURCES CO « 3 «'■'«' I-. 45 OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 00«-«Q0Q0OsiC'*00>-«0000O>O5?0OC000»-'C«-HloaiC^cOOC^O»O(?;t^00OO»-'l CS4 »-t ^H »H f-< .-I C^ 1-^ ,-, ,-H ^H l-H 1/5 l-l rH 1-H • KNNC^i-liOCC'-ti-H^ ^ -H^ ^^C^ •^ •-< ■^ f-t r^ »-t ■«*' .-r t-i r^ oo c>j i-" eO00O«-HC00sC^*:O00O^Hc0Os *:OOOO^HCOOSOOOOSC»'-<00003'©C«OOOiiOOS^Hr--QO»-1iOC^t^OOO .-< »-• i-H M ■^ rH 1-H »H r-t CO C^ *-« .-I -H •-< 42 a -as OS 000*MOOOOCOOt^OOOOOOOOOOOOOOOOOOOOOOOOOO eoo•^eoow^o•-'QO^c^oco»o»ooeoc^c-^oooot^|^^oooco^-coooo>o^-OO^^go OOCClOOOOOOOcOC001C<|iOO'--"OOOcOCOCOOOW500»-lC50SC^'i»* OOO ^M C^l^OO OO lO 00 ■^o wt ,_( * • » • C^» • O 03 O) O^ O) O O O^ OS 03 O O O O O^ Oi 0> O OS O OOSOSOSOSOdOiOsOOS o> o o> o> A o o 030>CAO>OS0390>CsO>CA030>CTSOSO>OS030S030SOSOSO>OS03030dOsa30>^<^OSO>OSO* CO O -^9*t^t^t^oi>^c^oor-co»o»ooit-t— cot- OSdC^t-tOCOOOOCO'-HTpCOCOCOCOCOCOC^COCOCO'-' »-H ^ 1-1 CO (M --• i-< OOOOOOOOOOOOOOOOOOOOOO r^-^CDOOroco-^LC:ric3Ct^roCi-^ — ;^cc-— cr. oo Oi c- c-i oc Ti ro cc o TT »o t^ >~^ ex «o — r>. r- --C i^ o > 3 O a o o. 00 3 O o o ^ ■a o *c S. _2 "w >> o o "a 8 3 & . C5 cn -«^ O . OS**- o . a> m-a a c » a> III 118 DIVISION OF WATER RESOURCES against the How of tlie Sacramento River ]iast Sacramento. Sep- arate graphs are sliown for Georgiana, Steamboat and Sutter slongli.s and tlie Sacramento River below the liead of Georgiana Slough. The data thus plotted show that a close relation exists between the flow in the Sacramento River past Sacramento and the flow through the various sloughs and the lower river. In the case of all these measurements of flow and the relations established, it must be understood that they apply especially to con- ditions which existed covering the range of measurements during the 1929 season. In all of the measurements, the flow into the delta from the San Joaquin River system was very small. It is possible that the relation shown as to division of flow would be changed with larger inflow coming from the San Joaquin River sy.stem but with like con- ditions of flow on the Sacramento River. Moreover, any changes in channel conditions or reclamation affecting tidal fluctuation and flow also might modify the relations established from the 1929 measurements. It is of interest to note that measurements in previous years of the flow through Georgiana Slough, including several made in the summer and fall of 1920 by engineers employed in the Antioch case and a single measurement in August, 1908, by the United States War Department,* check tlie curve on Plate XXVI reasonably closely. The measurements in 1920 were made for flows in the Sacramento River past Sacramento ranging from about 700 to 8000 second-feet and with small inflows from the San Joaquin River system of similar amount to 1929. The measurement made in 1908 was for a flow in the Sacramento River passing Courtland of about 7400 second-feet. These data from measurements in previous years indicate that the division of flow through Georgiana Slough was about the same as 1929, at least as far back as 1920 and possibly even in previous years. The flow from the Sacramento River through Georgiana and Three Mile sloughs into the San Joaquin Delta is of chief importance when the flow from the San Joaquin River sy.stem is small and insufficient in amount to meet the demands in the San Joaquin Delta for consumptive demands, present or proposed diversions to outside areas, and the repulsion of saline invasion. Hence, inasmuch as conditions approxi- mating those during the period of measurements in 1929 probably will prevail in the future during the summer and fall months, especially with future increase of storage and use of water on the San Joaquin River system, the distribution of flow^ and particularly the propor- tional flow through Georgiana Slough as shown by the 1929 measure- ments may be considered to be applicable to future conditions of con- snm|)tive d'-mands in the delta and salinity control. The only changes Avhich might affect the distribution of flow shown by the 1929 measure- ments and the accuracy of apjilying the relation shown to future years, would be channel dredging or reclamation works subsequent to 1929 that would i-esult in niodificatioii of tidal fluctnalion and flow.** • House document 1123, Sixtieth Congress, Second Session, House of Representa- tives, 1909, page IS. •♦ Since the mea.surements were made in 1929, considerable dredg^ing work was done by the United States War Department in the Sacramento River cliannel from Rio Vista up to the triple junction of Steamboat Slough, Cache Slough and the main river channel and also up into the main river channel toward Isleton. In order to determine, if possible, whether the changes thus made in the channel had modified the proportional flow through Georgiana Slough, a few measurements were made of PLATE XXVI COMBINED RIVER AND DELTA CHANNELS 10 20 30 ^^0 50 60 Flow of Sacramento River in thousands of second-feet >8 25 >4 >2 >0 8 16 14 12 10 8 6 4 2 SACRAMENTO RIVER BELOW HEAD OF GEORGIANA SLOUGH i i > y^ /^ / / / M / / y / > v y / 9. fa J. / / X §s / y -3 > 5 d " , " ^^ (0 10 20 30 40 SO 60 Flow of Sacramento River in thousands of second-feet SUTTER SLOUGH t 8 i/> 6 ^ ''''^. * 10 20 30 '.O 50 60 Flow of Sacramento River in thousands of second-feet COMBINED RIVER AND DELTA CHANNELS 3 O 10 20 30 40 50 60 Flow of Sacramento River in thousands of second-feet SACRAMENTO RIVER BELOW HEAD OF GEORGIANA SLOUQH •^22 _o I/) 20 <0 O ra O 12 s ' O Ql 6 1 1 y 1 / ^ 1 / "t / = / / s. y / / / / / « 5 ^ / i / ^ ss £ / • y 1 10 20 30 40 50 60 Flow of Sacramento River in thousands of second-feet DISTRIBUTION OF FLOW OF SACRAMENTO RIVER THROUGH BRANCH CHANNELS BCLOW SACRAMENTO 80995— p. lis O r> ;r h f o CM VARIATION AND CONTROL OP SALINITY 119 The flow through Georgiana Slough is of particular importance, because this slough is the chief connecting channel through which the San Joaquin Delta obtains water from the Sacramento River. Based upon the 1929 measurements, with a flow in the Sacramento River past Sacramento of 3000 second-feet, about 1300 second-feet or 43^ per cent of the total flow is discharged through Georgiana Slough into the San Joaquin Delta ; with 5000 second-feet, about 1800 second-feet or 36 per cent of the total flow; with 10,000 second-feet, about 2400 second-feet or 24 per cent; with 20,000 second-feet, about 3500 second-feet or 17^ per cent; with 40,000 second-feet, about 6000 second-feet or 15 per cent; and with 60,000 second-feet, about 9000 second-feet or 15 per cent. It is thus seen that, for the lower flows in the Sacramento River with conditions as in 1929, Georgiana Slough takes a relatively larger share of the total. As the flow of the Sacramento River increases, however, the percentage of the total which flows through Georgiana Slough decreases rapidly. The diagram in the upper right-hanrl corner of Plate XXVI shows the diA'ision of flow of the Sacramento River between the three sloughs, Georgiana, Steamboat and Sutter, and the Sacramento River below Georgiana Slough. For any flow of the Sacramento River pass- ing Sacramento, the division of flow through the separate channels can be obtained from the diagram. Points on the upper line of the diagram show the total combined flow through the four channels for any flow in the Sacramento River. It will be noted that the points on this line for any flow give total flows through the branch channels slightly less than the flow coming past Sacramento. This is to be expected inasmucli as a part of the total flow is diverted to irrigation or otherwise consumed. The results of the measurements of flow through Three Mile Slough show that no relation exists between the flow in the Sacramento River and the flow through this slough. Thus, in Table 11 which summarizes all of the measurements made and the corresponding flow of the Sacra- mento River past Sacramento, the measured flow through Three Mile Slough ranged from nothing to 2500 second-feet with a flow of 2500 to 2800 second-feet in the Sacramento River. "With a flow of 7000 second- feet in the Sacramento River, the measured flow through Three Mile Slough ranged for two separate measurements from about 600 to 1800 second-feet. The largest measured net flow tlirough Three Mile Slough occurred when the flow of the Sacramento River was 103.600 second- feet. However, this measured flow which amounted to about 3700 second-feet does not greatly exceed the measured flow on July 31 of 2500 second-feet when the flow of the Sacramento River was only 2590 second-feet. Therefore, it is concluded that the flow through Three Mile Slough is a tidal flow, the magnitude of which depends upon the character of the tide. the flow through Georgiana Slough in 1931. These covered ranges in flow of the Sacramento River past Sacramento from 4500 to ISOO second-feet. The results of these measurements indicate that the proportional amount of flow through Georgiana Slough has been decreased below that shown by the 1929 measurements; or in other words that a greater proportion of the flow passing "Walnut Grove is now i continuing down the main river channel than in 1929. However, the number of ' measurements made is not sufficient upon which to base a conclusion as to what I change, if any, has occurred in the division of. flow at this point. i ll 120 DIVISION OF WATER RESOURCES This fact is snp])ortod by tlie prrnplis on Plate XXVIT, "Relation of Flow Throujrh Three Mile Sloujrh to Kano V - \ obta from rame 1 1 in i ft 11 points shown were f measurements and st^e recorder at Sa 30 3 tion in hour - \ \o II points shown were ' measurements and strfe recorder at Saci 1 T "1 ZJ c f- " .2 \ \ - \ u** s-s. es \ ■li< i-S- ro \ ^ t 5: j: L. % fc ^ '^ i- Z 3 lO TO CM - \ z 3 (M VO \ A -0 c CO - ) I - -D C CO o\o - ° \ - \ - s| [\ jL •4- ~ ' \r V c : \ _ c A — '00 - \ - <0 ~ c u \ - v c ~ \ ~ (0 - \ - \ - u - \ - \ - .^ \ \ ~ - - L - 3 - D - \ 3 ■u _ "O _ 1 k — - - V o. - UI L^ - \ lO 1 1 1 1 1 t 1 1 1 1 1 1 r 1 r r 1 1 1 1 p c 3 O O « D C D C 5 O O o o o o o o o o o o o o N 00 <4- *£ ^ 00 1 1 1 1 1 1 1 1 1. 1,. V - 1 1 1 V V o w O 1- o *- ea <«> T} C (0 s^ CD 1. o I/) 4^ — o -o o t- O o o o Toward Toward San Joaquin River during flood Sacramento River during ebb Tidal flow in acre-feet from slack water to slack water at Three Mile Slough metering station RELATION OF TIDAL FLOW THROUGH THREE MILE SLOUGH TO RANGE AND DURATION OF TIDES AT PRESIDIO VARIATION AND CONTROL OF SALINITY 123 tion of the total flow remains in the Sacramento Delta and a constantly decreasing portion goes to the San Joaquin Delta. Thus, with 8000 second-feet in the Sacramento River, only about 3000 second-feet or 37 per cent would be carried to the San Joaquin Delta while 5000 second-feet or 63 per cent would remain in the Sacramento Delta. For flows less than 5200 second-feet, a larger portion of the total goes to the San Joaquin Delta. Thus with 3000 second-feet passing Sacramento, about 2200 second-feet or 73 per cent would go to the San Joaquin and about 800 second-feet or 27 per cent remain in the Sacramento River. All of these figures are based upon measurements for 1929, and might be modified for different conditions in future years. The total maximum rate of consumption in the delta is estimated at about 3700 second-feet. About two-thirds of this total, or 2500 second-feet, is estimated to be the maximum consumptive rate in the San Joaquin Delta. If it be assumed that all of the water required for the delta would have to come from the Sacramento River, a flow of about 3700 second-feet, or enough to satisfy the total water require- ments would result in a flow into the San Joaquin Delta of about 2300 second-feet, while about 1400 second-feet would remain in the Sacra- mento River channels. This indicates that the present channel capacity between the Sacramento and San Joaquin deltas, as shown by the 1929 measurements, would be just about sufficient to satisfy the proportionate consumptive water requirements, there being only a slight deficiency in the San Joaquin Delta. However, if the entire supply were coming from the Sacramento River and were just sufficient to meet the consumptive demands of the delta, there would be no excess stream flow available to keep saline w^ater from advancing into the delta. Since the San Joaquin Delta tidal basin lias a very much greater area and volume than the Sacramento Delta tidal basin, there would be a greater tendency for the saline water to advance into the San Joaquin than into the Sacramento Delta. Therefore, of the total additional inflow required to prevent saline invasion, the greater proportion of the total would be required in the San Joaquin Delta. If the entire flow required to repel saline invasion were to be furnished from the Sacramento River together with the total supply for consumptive use, the division of the total required flow would not be in proportion to the respective combined requirements of consumptive use and repulsion of saline invasion in the Sacramento and San Joaquin deltas. The portion of the total inflow going to the San -Toaquin Delta would be deficient. Therefore, under conditions where all or most of the water supply for the delta comes from the Sacramento River, it may be concluded that the present channel capacity connecting the two dleltas is insuffi- cient to provide the proportionate amount of water required for the San Joaquin Delta. Under present conditions this results usually in a greater extent of saline invasion into the San Joaquin Delta than into the Sacramento Delta, unless the inflow continuously available from the Sacramento River is considerably in excess of the total con- sumptive requirements of the delta. Moreover, if the entire future water requirements of the delta in the lieight of the growing season during the sunnner were to be furnished from the Sacramento River together with additional water supplies required for control of salinity, the ^ 124 DIVISION OF WATER RESOURCES effectiveness and flexibility of control would be limited by the lack of required channel capacity from the Sacramento River to the San Joaquin Delta, and it would be necessary to enlarge this connecting channel capacity in order to insure the most effective and efficient results from the water supplies provided. Water requirements for consumptive demands and salinity control in the San Joaquin Delta could be provided either by increasing tlie flow into the delta from the San Joaquin River and its main branches, or by making available a supply from the Sacramento River by increasing the present capacity of the interconnecting channels. To provide the greatest effectiveness, this additional channel capacity between the Sacramento River and the San Joaquin Delta should be placed as far upstream as possible so that the flow would be affected least by tidal action and above any point of possible pollution b}' saline invasion. An increase in channel capacity in the vicinity of Three Mile Slough would have little effectiveness on account of the marked variability and small amount of net flow through this channel. The matter of addi- tional channel capacity will be further discussed in Chapter V. Effect of Irrigation, Storage and Reclamation Developments on Stream Flow into Delta. The importance of stream flow as a primary factor governing salinit}^ conditions in the delta and bay channels has heretofore been demonstrated. Therefore, it is of special interest to consider the factors which have modified, or will modify, stream flow. The chief factors modifying stream flow are upstream irrigation and storage developments. Irrigation affects stream flow by a direct consumption of a part of the available natural floAv, whereas storage of water may affect not only the distribution of stream flow, but also may result in a final reduction of flow for such storage developments as are primarily for irrigation. As far as the delta and upper bay are concerned and the effect on salinity conditions therein, only developments which directly affect the distribution and amount of surface water in the natural streams Avhich flow into the delta are involved. Consideration has also been given to the affect of reclamation of upstream flood basins, chiefly in the Sacramento Valley, which is a third modifying factor. The compilation of data on irrigation and storage developments has been somewhat difficult. For the most part, authentic data on irrigated areas, irrigation diversions and storage operations are meagre and freciuently unavailable. A search has been made for all sources of data. These have included the U. S. census, State publications, results of unpublished investigations, reports of the U. S. Geological Survey and the U. S. Department of Agriculture, county assessor's records, records of irrigation districts and public and private irriga- tion companies, power companies and other miscellaneous agencies. The records have been compiled and critically analyzed and it is believed that the data presented are rea.sonably accurate and the best that can be obtained from the sources available. Growth of Irrigation — The practice of irrigation in California had its beginnings in the early days of the Spanish occupation. With the VARIATION AND CONTROL OF SALINITY 125 coining of the Spanish missionaries, ditches were constructed and water diverted from the streams near the missions for the irrigation of small areas of crops. With the coming of the American settlers into Cali- fornia in the fifties, the necessity of irrigation was immediately realized by the farmers and ditches were constructed and water diverted from the streams for this purpose. In many cases ditches constructed primarih^ for carrying out of hydraulic-mining enterprises supplied water for the irrigation of nearby farms. On the streams of the San Joaquin Valley draining directly to the delta area, the first extensive ditch system built primarily for irrigation was constructed in 1852 diverting water from the Merced River for the irrigation of bottom lands. The first large irrigation canal to be com- pleted in the San Joaquin Valley was the San Joaquin and Kings River Canal which started operation in 1871. This canal, the first of a number of canals to be constructed by the Miller and Lux interests, diverts water from the San Joaquin River. By 1890, almost all of the major irrigation systems taking their supply from tributaries of the San Joaquin River, including the Fresno, Merced, Tuolumne, Stanis- laus and Mokelumne rivers, had been started. On the main San Joa- quin River, considerable development occurred at a later period. Between Patterson and the delta, some irrigation was started as early as 1910 and additional lands were irrigated in 1911 and 1913. How- ever, most of the development taking its supply from this section of the stream was carried out after 1915. Irrigation in the Sacramento Valley was started just about as early as in the San Joaquin Valley. Development was much slower than in the San Joaquin Valley, due to the more abundant rainfall and to the unusual success of grain farming in the bonanza days of that industry. Most of the early irrigation was on farms in the mountain valleys and foothills served by water supplied from mining ditches. It was not until about 1910 that any great or rapid increase in irrigation development occurred in the Sacramento Valley. At about this time, because of the decline in grain prices and yields and the interest stimulated in irrigation, many of the larger ranches were subdivided and put under irrigation, giving rise to a rapid growth in irrigated agriculture. Later, in about 1916, a more rapid increase in area irrigated and in consumption of water by irrigation was brought about by the inception and growth of the rice industry. This was stimulated by the abnormal demand for foodstuffs during the World War. In 1920 the rice market broke and for the next three j^ears a decline was experienced in irrigated agriculture, mostly due to a reduction of rice farming. Since 1923, however, the area irrigated has again increased and reached a total acreage in excess of that in 1920. The area irrigated by direct diversion from the Sacramento and San Joaquin River systems is summarized for each year from 1879 to 1929 in Table 12, and graphically shown on Plate XXIX, "Growth in Area Irrigated by Direct Diversion from Sacramento and San Joaquin River Systems Exclusive of Delta of Sacramento and San Joaquin Rivers." Lands irrigated by wells are not included nor are there included any lands irrigated from the Kings River which at times is partially tributary to the San Joaquin River. In the Sacramento Valley, the irrigated area has gradually increased from about 80,000 126 DIVISION OF WATER RESOURCES acres in 187!) to about 22(),()()0 acres in 1910, 286,000 acres in 1915, 502,000 acres in 1920 and 537,000 acres in 1929. In tlie San Joaquin Valley, the area irrifrated {jraduallv increased from about 70,000 in 3879 to 170,000 acres in 1900, and then at a ^n-eater rate to about 780,000 acres in 1929. In the 20-year period since 1910, the combined area irrigated in the two valleys from the Sacramento and San Joaquin Kiver systems lias more than doubled. The growth in the Sacramento Valley during the last 15 years has been even more noteworthy, with nearly a 100 per cent increase in area irrigated. Most of this growth TABLE 12 AREA IRRIGATED BY DIRECT DIVERSION FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Exclusive of Sacramcnlo-San Joaquin Delta 1879-1929 Year Area irrigated from Sacramento River system in acres Area irrigated from San Joaquin River system in acres ■ Total area irrigated from the combined Sacramento and San Joaquin River systems in acres 1879 - - - --- -- 80,000 160,000 180,000 220,000 243,000 260,000 286,000 270,000 286,000 313,000 351,000 412,000 474,000 502,000 448,000 445,000 438,000 475,000 463.000 515,000 525,000 512,000 537,000 70,000 170,000 270,000 400,000 430,000 463,000 494,000 522,000 540,000 537.000 579,000 599,000 618,000 657,000 669,000 660,000 719.000 668,000 743,000 759,000 794,000 776,000 780,000 150,000 1900 330,000 1905 450,000 1910 - 620,000 1911 673,000 1912 -.- - 723,000 1913 - 780,000 1914 792,000 1915 -- 826.000 1916 -- 850,000 1917 - - --- 930,000 1918 . - 1,011,000 1919 - --- - 1,092,000 1920 - - 1,159,000 1921 . - 1,117,000 1922 . -- -- 1,105,000 1923 1,157,000 1924 1,143,000 1925 1,206,000 1926 -- 1,274,000 1927 - 1,319,000 1928 1,288,000 1929 - - - 1.317,000 Note. — This table was compiled from data obtained from the U. S. census, county horticultural reports, Stite Rail- road Commission files, irrigation district ani water company reports. Federal and State reports and estimates. occurred in the five-year period, 1915 to 1920, there having been an average increase during this period of over 40,000 acres per year. In the San Joaquin Valley, from 1900 to 1929, there lias been a fairly uniform growth averaging about 21,000 acres increase annually. The area irrigated in 1929 is a little less than one and one-hall: times that irrigated in 1915. For the total area irrigated from the combined river systems, the average growth from 1910 to 1929 has been at the rate of about 36,000 acres annually. During this period, the most rapid growth occurred from 1915 to 1920, chiefly as a reflection of the development in the Sacramento Valley, and was at the rate of about 67,000 acres annually. The foregoing data presented on irrigated areas are compiled from miscellaneous sources and it is not known whether they represent net or gross irrigated areas. However, this is not important in respect to the purpose of presenting these data, namely that of showing the general trend of growth in area irrigated VARIATION AND CONTROL OF SALINITY 127 PLATE XXIX SACRAMENTO RIVER SYSTEM € 4 2 — / S>o^ r-^-. — / — ~ o- r — ^875 1880 1885 1890 1895 1900 1905 1910 1915 1920 1925 1930 § SAN JOAQUIN Driver system hundred thousands of i - ^<^ wV y^- - A ^ — — ^ y - o- y^ — .C 1875 1880 1885 1890 1895 1900 1905 1910 1915 1920 1925 1930 (0 Year 2 COMBINED SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS -co 12 i- g 10 c c 75 8 6 4 2 - r- - / ^ - i — - t V r — - > Y — - y — o- ""^^ — i75 1880 1885 1890 1895 1900 1905 1910 1915 1920 1925 19 Year 30 GROWTH IN AREA IRRIGATED BY DIRECT DIVERSION FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS EXCLUSIVE OF DELTA OF SACRAMENTO AND SAN JOAQUIN RIVERS 128 DIVISION OF WATER RESOURCES upstream from the delta by direct diversions from the Sacramento and San Joaquin River systems. These data on area irrigated reflect the effect that irrigation has had upon natural stream flow into the delta. However, the magnitude of this effect is more clearly shown by the amounts of irrigation diver- sions. Records and estimates of irrigation diversions from the Sacra- mento and San Joaquin River systems have been compiled by seasons to show the growth in irrigation diversions and by months to show the amount and variation of the monthly distribution of seasonal diver- sions. Table 13 and Plate XXX, "Growth of Irrigation Diversions from Sacramento and San Joaquin River Sy.stems, " show the total annual gross irrigation diversions from 1879 to 1929. Irrigation diver- sions in the Sacramento-San Joaquin Delta and in the San Joaquin Valley from the Kings River south are not included. The data presented on animal gross irrigation diversions are partly based upon actual records and partly upon estimates. The estimated amounts have been computed from the irrigated areas, using the best available information as to probable duty of water in acre- feet per acre. For the earlier years, prior to 1900, the figures are practically all estimated. Since 1924, about 70 per cent of the amounts shown for the Sacramento River system, is from actual records. For the San Joa((uin River system, hoAvever, from Go to 90 per cent or more of the amounts shown are from actual records as far back as 1912; and, with the exception of 1925 when about 30 per cent of the amount shown was estimated, 85 to 92 per cent of the amounts shown from 1919 to 1929 is from actual records. TABLE 13 GROSS ANNUAL IRRIGATION DIVERSIONS FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Exclusive of Sacramcnio-S'jn Joaquin Delta 1879-1929 Year Gross diversions from Sacramento River system in acre-feet Gross diversions from San Joaquin River system in acre-feet Total poss diversions from combined Sacramento and San Joaquin River systems in acre-feet 1879 333,000 640.000 730,000 942.000 1,106,000 1,094,000 1.106,000 1,154,000 1,443,000 1,567,000 674.000 921,000 1,529.000 1,809,000 2,135,000 2,1.30,000 2,541,000 2,352,000 2,560,000 2,755,000 1,007,000 1900 1,561,000 1905 2,259,000 1910 . - 2,751,000 1912 3,241,000 1913 - --. 3,224,000 1914 3,647,000 1915 - 3,506,000 1916 -. - 4,003,000 1917- 4,322,000 1918 1,914,000 2,329,000 2,273,000 2,221,000 2,196,000 2,138,000 2.171,000 2.108,000 2,492,000 2,654,000 2,476,000 2.425.000 2,590,000 2,281,000 2.433,000 2,643,000 2,550,000 3,00 -',000 1,770,000 2,745,000 2,706,000 3,203,000 2,855,000 2,707,000 4.504,000 1919 4,610,000 1920 4,706,000 1921 4,864,000 1922 4,746,000 1923 . 5,140,000 1924 - 3,941,000 1925 - 4,853,000 1926 5,198,000 1927 5.857,000 1928 --- 5.331.000 1929 .-. 5,132,000 NoTB. — Compiled from data obtained from the U. S. census, county horticultural report. State Railroad Commis- sion files, irrigation district and water company reports and estimates, Federal and State reports, and estimates. VARIATION AND CONTROL OF SALINITY 129 PLATE XXX SACRAMENTO RIVER SYSTEM 3| I I M I I I M I M I I I I I I I I I I I I M I I I I I I I I I M I I I I I I I I M I I I I I I I I I I I I I I I 1875 1880 1885 1890 1895 1900 1905 1910 1915 1920 1925 1930 Year .4J L. O (0 c I 2 E c I c o SAN JOAQUIN RIVER SYSTEM 2 0. 1 1 1 1 1 1 M 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 I'M 1 M 1 Mil MM MM - - - A _ >V fj[ i l/v - A, r\J Y^\i - - .^ 1 '^ V - _ ' 8 _ _ _ - ^^^^^ .---^ - _LJ_ii_ ,J..Li„ ! J 1 1 n 1 1 1 1 MM .i.i-U_ -Dry se -of 1923 .1 1J_L "l 1 1 1 1 1 1 1 III! 1- > (0 6 c c (0 •t- 1^ 4 1875 1880 1885 1890 1895 1900 I90S 1910 1915 1920 1925 1930 Year COMBINED SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS I M M I I I I I M II I M II I I II M M I l| I I II I M II I ! M 11 I I I [ I I k M O' M I M I I I M M M If I II M II I II I ll I M I ll M I |_UJ UJ_L 1875 1880 1885 1890 1895 1900 1905 1910 1915 1920 1925 1930 Year GROWTH OF IRRIGATION DIVERSIONS FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS 9—80995 130 DIVISION OF WATER RESOURCES The data indicate that the gross annual irrigation diversions have increased over five times in the 50-year period from 1879 to 1929. For the San Joaquin River system, annual irrigation diversions gradually increased from 074,000 acre-feet in 1879 to 921,000 acre-feet in 1900, and then at a more rapid rate to about 3,000,000 acre-feet in 1923, and 3,200,000 acre-feet in 1927. The decrease in annual irrigation diver- sions since 1927 and in 1924 has been due chiefly to deficient water supply during dry j^ears. This effect of deficient M'ater supply is particularly noteworthy in 1924 when there was an abrupt drop from 1923 to 1924 of about 1,230,000 acre-feet or about 40 per cent of the total diverted in 1923. As of 1929 the gross annual irrigation diver- sions from the San Joaquin River system api)ear to be at the rate of about 3.5 acre-feet per acre of area irrigated. From the Sacramento River system, gross annual irrigation diver- sions gradually increased from 333,000 acre-feet in 1879 to 640,000 acre- feet in 1900, and then at a slightly greater rate to 1,154,000 acre-feet in 1915. From 1915 to 1920 a much more rapid increase occurred due to the rice industry, gross annual diversions increasing to about 2,300,- 000 acre-feet in 1919 and 1920. Following the failure of the rice industry in 1920, the use of water from the Sacramento River system slightly decreased up to 1925 and then gradually increased in the next two years, reaching a total of over 2,600,000 acre-feet in 1927. As of 1929, the gro.ss annual irrigation diversions from the Sacramento River S3%stem appear to be at the rate of about 4.5 acre-feet per acre of area irrigated. This larger rate of use in the Sacramento Valley as com- pared with the San Joaquin Valley is due to the large acreage of rice which is a heavy water user, and the relatively large use of water in the mountain valleys. For the combined Sacramento and San Joaquin River systems, the gross annual irrigation diversions as of 1929 appear to be at the rate of about 3.9 acre-feet per acre. The growth in gross annual irrigation diversions in general indi- cates the total magnitude of the progressively increasing diminution of natural stream flow by irrigation. However, all of the water diverted is not actually consumed by the crops and it is estimated from records of return water measurements which have been made during the period 1924 to 1929, that from 35 to 40 per cent or more of the gross irriga- tion diversions for the main valley lands is returned to the streams and becomes available for use at farther downstream points. Hence, as an approximation, the actual total reduction in natural stream flow of the Sacramento and San Joaquin River system into the delta, due to irrigation, may be considered to be about two-thirds of the gross annual diversions. The amount of water diverted for irrigation from month to month during the irrigation season varies considerably. Therefore, in order to ascertain the effect of irrigation diversions on stream flow into the delta, the amounts diverted month by month are of special importance and have been compiled for the period 1912 to 1929 from available records and estimates. Records are available on some of the larger canals and irrigation systems over a considerable period of time. Measurements by the Sacramento-San Joaquin water supervisor are available for the years 1924 to 1929 for the Sacramento River system and for the diversions to the delta uplands from the lower "San Joaquin VARIATION AND CONTROL OF SALINITY 131 TABLE 14 GROSS MONTHLY IRRIGATION DIVERSIONS FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Exclusive of Sacramento-San Joaquin Delta 1912 to 1929 Year and month 1912— January February March ApriL May June July August September October November December Total annual 1913— January February March April May June July August September October November December Total annual 1914— January February March ApriL. May June July August September October November December Total annual 1915— January February March April May ,June fuly fAugust "iptember stober fovember tDecember > Total annual Gross diversions from Sacramento River system in acre-feet Gross diversions from San Joaquin River system in acre-feet 4,000 124,000 225,000 221,000 191,000 161,000 154,000 25,000 1,000 1,106,000 43,000 77,000 188,000 286,000 446,000 38?,000 288,000 171,000 118,000 68,000 36,000 32,000 2,135,000 Total gross diversions from combined Sacramento and San Joaquin River systems in acre-feet 43,000 77,000 192,000 410,000 671,000 603,000 479,000 332,000 272,000 93,000 37,000 32,000 3,241,000 I 3,000 116,000 216,000 217,000 194,000 166,000 153,000 28,000 1,000 1,094,000 43,000 77,000 187,000 286,000 445,000 381,000 288,000 170,000 117,000 68,000 36.000 32,000 2,130,000 43,000 77,000 190,000 402,000 661,000 598,000 482,000 336,000 270,000 96,000 37,000 32,000 3,224,000 2,000 112,000 214,000 218,000 200,000 173,000 155,000 31,000 1,000 1,106,000 51,000 91,000 224,000 341,000 531,000 455,000 343,000 203,000 140,000 81,000 43,000 38,000 2,541,000 51,000 91,000 226,000 453,000 745,000 673,000 543,000 376,000 295,000 112,000 44,000 38,000 3,647,000 3,000 119,000 226,000 228,000 207,000 178,000 161,000 31,000 1,000 1,154,000 47,000 85,000 207,000 315,000 492,000 421,000 318,000 188,000 129,000 75,000 40,000 35,000 2,352,000 47,000 85,000 210,000 434,000 718,000 649,000 525,000 366,000 290,000 106,000 41,000 35,000 3,506,000 132 DIVISION OF WATER RESOURCES TABLE 14— Continued GROSS MONTHLY IRRIGATION DIVERSIONS FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Exclusive of Sacramento-San Joaquin Delta 1912 to 1929 Year and month Gross diversions from Sacramento River system in acre-feet Gross diversions from San Joaquin River system in acre-feet Total gross diversions from combined Sacramento and San Joaquin River systems in acre-feet 1916— January February March April May June - July August September October November December Total annual 1917— January February March April May June July August September October November December Total annual 1918— January February March April May June July....- August September October November December Total annual 1919— January February March April Nlay June July August.- September October November December Total annual 5,000 135,000 270,000 285,000 270,000 235,000 198,000 43,000 2,000 1,443,000 7,000 142,000 290,000 310,000 296,000 260,000 213.000 47.000 2,000 1,567,000 51,000 92,000 225.000 343.000 535,000 458,000 346,000 205,000 141,000 82,000 44,000 38,000 2,560,000 55,000 99,000 242,000 369,000 576,000 493,000 372,000 221,000 152,000 88,000 47,000 41,000 2,755,000 6,000 154,000 347,000 383.000 377.000 333.000 254,000 58.000 2.000 1.914.000 52,000 93,000 228,000 347,000 541.000 464,000 350,000 207.000 142,000 83,000 44,000 39,000 2,590,000 7,000 179,000 418,000 467,000 465,000 413,000 305,000 73.000 2.000 2,329,000 47,000 84,000 204,000 312,000 486,000 417,000 314,000 186.000 128,000 52,000 25.000 26,000 2,281,000 VARIATION AND CONTROL OF SALINITY 133 TABLE 14— Continued GROSS MONTHLY IRRIGATION DIVERSIONS FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Exclusive of Sacramcnto-San Joaquin D;lta 1912 to 1929 Year and month Gross diversions from Sacramento River system in acre-feet Gross diversions from San Joaquin River system in acre-feet Total ^ross diversions from combined Sacramento and San Joaqnin River systems in acre-feet 1920— January February March April May June July — . August---* September October November December Total annual 1921— January February March April... May June July August September October November December Total annual 1922— January February March April May June July August September October. November December Total annual 1923— January February March April Mlay June July August September October November December Total annual 3,000 167,000 406,000 457,000 458,000 409,000 299,000 72,000 2,000 2,273,000 39,000 58,000 225,000 411,000 559,000 519,000 269,000 120,000 93,000 67,000 41,000 32,000 2,433,000 39,000 58,000 228,000 578,000 965,000 976,000 727,000 529,000 392,000 139,000 43,000 32,000 4,706,000 7,000 169,000 397,000 445,000 444,000 395,000 291,000 71,000 2,000 2,221,000 35,000 70,000 203,000 399,000 559,000 610,000 397,000 139,000 99,000 63,000 38,000 31,000 2,643,000 35,000 70,000 210,000 568,000 956,000 1,055,000 841,000 534,000 390,000 134,000 40,000 31,000 4,864,000 7,000 169,000 391,000 438,000 438,000 390,000 290,000 71,000 2,000 2,196,000 50,000 51,000 116,000 231,000 567,000 617,000 514,000 184,000 108,000 70,000 26,000 16,000 2,550,000 50,000 51,000 123,000 400,000 958,000 1,055,000 952,000 574,000 398,000 141,000 28,000 16,000 4,746,000 6,000 165,000 384,000 428,000 425,000 378,000 282,000 68,000 2,000 2,138,000 20,000 71,000 242,000 361,000 637,000 600,000 450,000 260,000 163,000 109,000 54,000 35,000 3,002.000 20,000 71,000 248,000 526,000 1,021,000 1,028,000 875,000 638,000 445,000 177,000 56,000 35,000 5,140,000 134 DIVISION OF WATER RESOURCES TABLE 14— Continued GROSS MONTHLY IRRIGATION DIVERSIONS FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Exclusive of Sacramento-San Joaquin Delta 1912 to 1929 Year and month Gross diversions from Sacramento River system in acre-feet Gross diversions from San Joaquin River system in acre-feet Total ^oss diversions from combined Sacramento and San Joaquin River systems in acre-feet 1924- Januarv _- -- 3,000 223,000 414,000 423,000 410,000 357,000 277,000 62,000 2,000 2,171,000 39,000 88,000 170,000 296,000 439,000 210,000 168,000 132,000 81,000 62,000 50.000 35,000 1,770,000 39.000 88.000 173.000 April 519.000 853,000 633.000 July - -- 578.000 August . 489,000 358,000 October .- -- 124,000 November . 52.000 December -- 35.000 3.941.000 1925— 6,000 126,000 315,000 426,000 447.000 403,000 318,000 65.000 2,000 2,108,000 79,000 86,000 180,000 300,000 556,000 578,000 417,000 226,000 156,000 90,000 44,000 33,000 2,745,000 79.000 February _ 86.000 186,000 426,000 May - - - 871,000 June - . - 1,004,000 July _. __ 864,000 Auzust _ 629.000 474,000 155,000 46,000 December 33,000 Total annual 4,853,000 1926- 7,000 164,000 447.000 525.000 517,000 453,000 299,000 78,000 2.000 2.492.000 54,000 106,000 242,000 409,000 590,000 404,000 312,000 244,000 156,000 92,000 62.000 35,000 2.706,000 54,000 February 106,000 249,000 J 73,000 1,037,000 June _ 929,000 July 829.000 August - - - 697.000 455.000 October 170.000 64.000 35.000 5.198.000 1927- 8.000 168.000 474.000 521.000 540.000 488,000 355,000 97,000 3,000- 2,654,000 59,000 42,000 133,000 323.000 633.000 630.000 517.000 351,000 270,000 152,000 50,000 43.000 3.203,000 59,000 42,000 141,000 April 491,000 1,107.000 June .... 1.151.000 July 1.057.000 839.000 Seotember _ _ . 625.000 October 249.000 53.000 43.000 Total annual 5.857.000 VARIATION AND CONTROL OF SALINITY 135 TABLE 14— Continued GROSS MONTHLY IRRIGATION DIVERSIONS FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Exclusive of SacrEmentfj-San Joaquin Delta I9I2 to 1929 Year and month 1928— January February March April May June July August September October November December Total annual 1929— January February March April- May June July _... August September October November December Total annual Gross diversions from Sacramento River system in acre-feet 7,000 184,000 464,000 502,000 491,000 448,000 299,000 79,000 2,000 2,476,000 Total gross Gross diversions from diversions from San Joaquin combined Sacramento and San Joaquin River systems River system in acre-feet in acre-feet 34,000 34,000 79,000 79,000 179,000 186,000 318,000 502,000 609,000 1,073,000 489,000 991,000 369,000 860,000 312,000 760,000 238,000 537,000 125,000 204,000 65,000 67,000 38,000 38,000 2,855,000 5,331,000 16,000 16,000 46,000 46,000 162,000 166,000 363,000 658,000 5; 0,000 1,063,000 410,000 841,000 382,000 827,000 364,000 763,000 211,000 485,000 95,000 177,000 46,000 48,000 42,000 42.000 2,707,000 5,132.000 4,000 295,000 493,000 431,000 445,000 399,000 274,000 82,000 2,000 2,425,000 Note. — This table was compiled from data obtained from the U. S. census, county horticultural reports. Slate Railroad Commission files, irrigation district and water company reports and estimates. Federal and State reports, and estimates. 136 DIVISION OP WATER RESOURCES River and tributary eliannels of the delta. On the San Joaquin River system, there are records of the diversions from the Tuolumne and Stanislaus rivers, from the main San Joaquin River through some of the Miller and Lux canals, from the Fresno River (Madera Canal) and from the jMereed and ]Mokelumne rivers. These afford a fairly complete record during the period 1920 to 1929, but estimates in a few instances were necessary to complete periods of missing records. No records Avere available for the Chowchilla. Calaveras and Cosumnes rivers. Where no records were available, the monthly diversions were estimated from the total annual diversions based upon the best data available as to the monthly distribution of total annual use. The estimates of the monthly diversions for periods of missing records were based upon actual measurements on irrigation sj'stems supplying areas of similar character. The gross monthly irrigation diversions are summarized for the years 1912 to 1929, inclusive, in Table 14, and are graphically shown on the lower diagram of Plate XXXI, '* Monthly Diversions for Irri- gation and Storage from Sacramento and San Joaquin River Systems, Exclusive of Deltas of Sacramento and San Joaquin Rivers." The data presented, although approximate, furnish a reasonable estimate of the gross monthly irrigation diversions, and afford a basis for judg- ing the gross amount of the progressively increasing monthly diminu- tion of stream flow into the delta bv direct irrigation diversions. Growth of Reservoir Storage Developments — The growth and develop- ment of storage works for irrigation, power and municipal Avater supply is another important factor modifying stream flow into the delta. Data have been gathered on reservoir storage capacity and on the amounts diverted to and relea.sed from storage. The data have been obtained from all available sources and include all of the important storage developments on the Sacramento and San Joaquin River sy.stems. Table 15 and Plate XXXII, "Growth of Reservoir Storage Capac- ity in Sacramento and San Joaquin River Systems," show the growth in reservoir storage capacity for the Sacramento River and the San Joacpiin River systems separately and combined. The capacity of storage reservoirs for the combined river systems increa.sed from about 2000 acre-feet in 1850, which is the earliest record available, to about 200,000 acre-feet in 1907, or an increase at the rate of only 3500 acre- feet i)er year. Most of the storage development has occurred since 1910, and about two-thirds of the total since 1920. In the period 1910 to 1929, new storage developments have been constructed on the Sacramento River system to the amount of 2,171,000 acre-feet, and on the San Joaciuin River system to the amount of 1,576,000 acre-feet. Nearly 3,000,000 acre-feet of storage on the combined river systems was added from 1920 to 1929. The average rate of growth of storage capacity on the combined river systems from 1910 to 1929 lias been about 200.000 acre-feet per year. This develojnnent has been partly for irrigation, partly for power and to a smaller extent for municipal water sujijJy. Table 16 .summarizes data for the more important reser- voirs having a capacity of 50,000 acre-feet or more, showing gross storage ca)>aeity. date of construction, location and the purpose for which the water is used. PLATE XXXI ^QUIN RIVER SYSTEMS j:Sd. ?' ^ ^^$' ments have been constructed on the Sacramento River system to the amount of 2,171,000 acre-feet, and on the San Joaciuin River system to the amount of 1,576,000 acre-feet. Nearly 3,000,000 acre-feet of storage on the combined river systems was added from 1920 to 1929. The average rate of growth of storage capacity on the combined river systems from 1910 to 1929 has been about 200,000 acre-feet per year. This development has been partly for irrigation, partly for ]iower and to a smaller extent for municipal water supjily. Table 16 summarizes data for the more important reser- voirs having a capacity of 50,000 acre-feet or more, showing gross storage capacity, date of construction, location and the purpo.se for which the water is used. I PLATE XXXI DIVERSIONS TO RESERVOIR STORAGE FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS 1915 i9ie 1917 1918 1919 1822 1923 1924 1925 1926 1920 1921 Year DIVERSIONS FOR IRRIGATION FROM SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS 1927 1928 1929 1,200 1920 1321 Year LEGEND Sacramento River System San Joaquin River System 80995 — p. 136 MONTHLY DIVERSIONS FOR IRRIGATION AND STORAGE FROM SACRAMLNTO AND SAN JOAOUIN RIVER SYSTEMS EXCLUSIVE or DELTAS OF SACRAMENTO AND SAN JOAOUIN RIVERS jir*. ir>Gi\/in ^ 4>7- U\ i c 00$ 5 3, 00! (yr , 01 a r t <9 in s* I VARIATION AND CONTROL OF SALl5lITY 137 TABLE 15 RESERVOIR STORAGE CAPACITY ON SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS 1850-1929 Year 1850. 1852. 1855. 1856. 1857. 1859. 1962. 1864. 1870. 1871. 1872. 1873. 1874. 1875. 1876. 1877. 1878. 1880. 1881. 1883. 1884. 1885 1887 1888. 1890 1891. 1895 1898. 1899 1900 1901 1902 1905 1907 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 Sacramento River system Storage capacity added in acre-feet 2,000 2,000 15,000 16,000 10,000 4,000 1,000 12,000 3,000 1,000 10,000 3,000 1,000 16,000 -15,000 8,000 5,000 1,000 1,000 1,000 8,000 . 3,000 11,000 2,000 2,000 56,000 2,000 10,000 1,000 47,000 535,000 3,000 26,000 79,000 24,000 12,000 1,000 80,000 3,000 6,000 79,000 46,000 1.041,000 14,000 165,000 ^-1,000 Accumulated storage capacity in acre-feet 2,000 2,000 4,000 19,000 19,000 35,000 35,000 45,000 49,000 50,000 62,000 65,000 65,000 66,000 76,000 79,000 80,000 80,000 96,000 81,000 89,000 94,000 94,000 94,000 95,000 95,000 96,000 97,000 97,000 105,000 108,000 119,000 121,000 123,000 179,000 181,000 191,000 192,000 239,000 774,000 777,000 803,000 882,000 906,000 918,000 919,000 999,000 1,022,000 1,008,000 1,087,000 1,133,000 2,174,000 2,188,000 2,353,000 2,352,000 1 Joaquin River system Storage capacity added in acre-feet 3,000 4,000 1,000 10,000 7,000 4,000 6,000 1,000 15,000 1,000 1,000 3,000 5,000 1,000 6,000 7,000 2,000 2,000 2,000 5,000 86,000 89,000 49,000 17,000 28,000 36,000 4,000 3,000 26,000 469,000 466,000 136,000 240,000 13,000 Accumulated storage capacity in acre-feet 3,000 3,000 7,000 8,000 8,000 18,000 18,000 18,000 18,000 25,000 25,000 29,000 29,000 35,000 35,000 35,000 36,000 36,000 36,000 51,000 52,000 53,000 56,000 56,000 61,000 61,000 62,000 68,000 75,000 77,000 79,000 79,000 81,000 86,000 172,000 172,000 172,000 261,000 261,000 310,000 327,000 355,000 391,000 391,000 395,000 398,000 424,000 893,000 893,000 893,000 1,359,000 1,495,000 1,735,000 1,748,000 Combined Sacramento and San Joaquin River systems Storage capacity added in acre-feet 2,000 3,000 2,000 19,000 1,000 16,000 10,000 10,000 4,000 1,000 19,000 3,000 4,000 1,000 16,000 3,000 1,000 1,000 16,000 '-15,000 23,000 6.000 1,000 3,000 1.000 5,000 1,000 2,000 6,000 15,000 5,000 13,000 2,000 4,000 61,000 88,000 10,000 1,000 136,000 535,000 52,000 43,000 107,000 60,000 12,000 5,000 83,000 29,000 475,000 79,000 46,000 1,507,000 150,000 405,000 12,000 Accumulated storage capacity in acre-feet 2,000 5,000 7,000 26,000 27,000 43,000 53,000 63,000 67,000 68,000 87,000 90,000 94,000 95,000 111,000 114,000 115,000 116,000 132,000 117,000 140,000 146,000 147,000 150,000 151,000 156,000 157,000 159,000 165,000 180,000 185,000 198,000 200,000 204,000 265,000 353,000 363,000 364,000 500,000 1,035,000 1,087,000 1,130,000 1,237,000 1,297,000 1,309,000 1,314,000 1,397,000 1,426,000 1,901,000 1,980,000 2,026,000 3,533,000 3,683,000 4,088,000 4,100,000 • English dam on the Middle Yuba River failed. 2 Dams in Modoc County failed. Notes: This table was compiled from data from the following sources: Bulletin No. 100, "Report of Irrigation Investigations in California." United States Department of Agriculture, Office of Experiment Stations, 1901. "Practical Treatise on Hydraulic Mining," August J. Bowie, 1885. "Reservoirs for Irrigation and Water Supply," James D. Schuyler, 1900. Water Supply Paper No. 493, 1923. Bulletin No. 21, "Irrigation Districtsin California," Division of Engineering and Irrigation, 1929. Data on file in office of Siate Engineer. 138 "DIVISION OF WATER RESOURCES TABLE 16 PRINCIPAL STORAGE RESERVOIRS ON SACRAMENTO AND SAN JOAQUIN RIVER SYSTEMS Including only reservoirs of 50,000 acre-feet or more capacity. Stream Reservoir Date of construc- tion Total stor- age capacity in acre-feet Use of water Stony Creek... Feather River. Pit River... Yuba River. Mokelumne River. Stanislaus River.. Tuolumne River. . Merced River San Joaquin River East Park Stony Gorge Lake Al manor Lake Almanor Lake Almanor Butt Valley Bucks Creek Big Sage Bowman Bowman Lake Spaulding.. Lake Spaulding.. Lake Spaulding.. Pardee Mclones Hetch Hetchy Don Pedro Exchequer- Huntington Lake Huntington Lake. Florence Lake Shaver Lake 1910 1928 1914 1917 1927 1924 1928 1921 1876 1927 1913 1916 1919 1929 1926 1923 1923 1926 1913 1917 1926 1927 51,000 50,200 224,000 300,000 1,308,000 49,800 lO^.OOO ♦77,000 20,700 67,000 43,500 64,000 74,500 222,000 113,000 206,000 290,r00 279,000 45,000 88,800 64,400 135,300 Irrigation Irrigation Power and Power and Power and Power and Power and Irrigation Irrigation. Irrigation. Power and Power and Power and Municipal Power and Power and Power and Power and Power Power Power Power irrigation irrigation irrigation irrigation irrigation power and mining power and mining irrigation irrigation irrigation irrigation municipal irrigation irrigation 'Largest volume stored, 22,500 acre-feet in 1922. VARIATION AND CONTROL OF SALINITY 139 PLATE XXXII SACRAMENTO RIVER SYSTEM V ^ 1850 I ^ 2 c o E c - /- - t - I860 1870 1880 1900 1910 1890 Year SAN JOAQUIN RIVER SYSTEM 1920 1930 .^ o (O a. (0 o (U ittO o ■(- to o > L. 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'" DEriV .?•' ;»''>■■■ % /'■ i.iiTjia / /-:• fe >v> y ^ 'i \ ■-UCiCJ^Ui/ 152 DIVISION OF WATER RESOURCES The water level in the tidal basin of San Francisco Bay is never a continuous plane surface at the same instant. The mean water level (see Plate XV) closel.y approximates a plane surface which in general extends on a rising slope from the Golden Gate to the upper limits of the basin. However, at any particular time, the actual level at various points in the basin is above and below this mean level. This is due to the fact that there is a lag in occurrence of tidal phases at points upstream from the Golden Gate, which increases with greater distance from the Golden Gate. This lag amounts to as much as 10 hours or more for points at the extreme upper limits of the tidal basin on the Sacramento and San Joaquin rivers. Since the tide in San Francisco Bay usually rises and falls twice in a lunar day of approximately 24 to 25 hours, with four tidal phases comprising two high and two low water levels occurring during this period at intervals approximately six hours apart, identical tidal phases or stages occur at different times and different tidal phases or stages occur at the same time at various points in the tidal basin. At the present time, the effect of tidal action is felt at points as far upstream as a few miles below Verona (near mouth of Feather River) on the Sacramento River, between Mossdale Bridge and Vernalis on the San Joaquin River and between New Hope Bridge and Thornton on the Mokelumne River. These limits vary considerably throughout the season, depending upon the magnitude of stream inflow and tidal action. During the winter and spring when the streams are in flood, the limits of tidal action are forced a considerable distance downstream. Thus, on the Sacramento River, the records show that when the flow of the Sacramento River passing Sacramento reaches about 25,000 second-feet, there is no tidal action at Sacramento. As the flow of the Sacramento River increases, the limit of tidal action is forced still fartlier downstream to the vicinity of Freeport. Similarly on the San Joaquin River, the effect of tidal action is eliminated at the Mossdale Bridge when the flow of the San Joaquin River reaches about 13,000 second-feet or more. During large flood flows, it is stated by observers in the delta that the effect of tidal action is eliminated as far down- stream as McDonald Island on the San Joaquin River and the Santa Fe Railroad crossing on Middle River. During periods of large floods, the range of the tide within the limits of tidal action is materially reduced at all points as far down as the mouth of the two rivers at Collinsville. For the period of low stream flow, tlie minimum, maximum and average ranges of the tide at the various points in the delta and bay channels are summarized in Table 5, and are graphically shown on Plate XV. Historical Limits — ^IJnder natural conditions, before any development of reclamation occurred within the delta, the tidal basin potentially embraced a large part of the delta area. Most of the lands within the delta were originally low-lying marsh lands, of varying elevation. If it be assumed tliat the mean water level at various points in the delta was about the same under the original natural conditions as at present, it is possible to estimate the original boundary line of the limits of tidal action. This boundary line showing the estimated limit of tidal action under natural conditions in the delta is shown in red on Plate XXXIV, "Tidal Basin of Sacramento-San Joaquin Delta PLATE XXXIV ME^N- DEPARTURE IN TIME OF ACTUAL TIDAL. PHASE FROM MEAN TIME OP ALT- FOUR TIDAL PHASES station Jiame Bigh-Blah Phaae nourit-Minutet of tide Bigh^Low Hour»-MiilMt«» Low-Low fiour»-jnniitei 0:00 0:00 0:00 0:00 Hanun Point ., , — y;06 —0:08 +0:06 + 0:08 Sjin M«tr.} Bridge . -0,1S — 0:!1 + 0:18 + 0:16 iunil>iiir..n Bridge . ~0 :09 — 0:!0 +0:i2 + 0:17 t-olnt BluK -0:01 —0:01 +0:01 + 0:02 Oakland Mole... —0:0* —0:04 +0:03 +0:OB + 0:07 + 0:0! + 0:04 +0:06 I'Lntl* P.>int . -^):06 -0:08 BMCon No. 8- -O.OK — 0;10 + 0:08 +0:19 Sonoinft Crttk . — 0:!6 -0:17 —0:06 +0:64 Pe tsl uniB Creek . -0:!6 —0:18 —0:08 +0:59 - —0:11 —0:09 + 0:0J — «.p)l Miir* I-lanil -0:0S , — >«:• + T*;«4. »0:0— dO:04- Sttitt-f W:0- 1/ '-' . 1^ «4:0 + $4); 9+ fliiO— X fi ^^:0f 80:0— V8:0— •:?! OJ- Sb^^ hk-o- ^6:0- -Jla^O Hfn :-.o + o0:0+ di:0 vSiO-i- ♦ 0:04- «r:0 »»!0+ |iJfl+ aS:Q ai; VARIATION AND CONTROL OF SALINITY 153 and Upper San Francisco Bay Region, Showing Progressive Changes in Reclamation Development, Time of Occurrence of Tidal Phases and Tidal Flow Stations." This line is drawn at the intersection of the present mean water level during the low water season at the various points in the delta with the corresponding ground elevation or contour. In addition to the area shown within this boundary, tidal action extended up the channels of Sacramento, San Joaquin and Mokelumne rivers about the same distance as at present. Under natural conditions, the potential gross area of the tidal basin in the delta within the red line on Plate XXXIV comprised about 300,000 acres. However, it appears that only a portion of the lands potentially within the tidal basin were actualh^ submerged by tidal fluctuations during the period of low stream flow in the summer and fall months. The limits of the tidal basin and the volume in the tidal prism have been modified in past years by three important agencies ; namely, hydraulic mining and natural erosion, channel erosion and improve- ments, and reclamation. Effect of Hydraulic Mining and Silting — The Sacramento and San Joa- quin River systems when in flood bring down large quantities of debris from the natural erosion of the valleys, foothills and mountains. It has been estimated * that the volume of material brought down by the Sac- ramento and San Joaquin rivers from this natural erosion amounted to 700,000,000 cubic yards during the 65-year period, 1850 to 1914, or about 11,000,000 cubic yards per year on the average. Of this total it is estimated that 420,000,000 cubic yards or an average of about 6,500,- 000 cubic yards per year was brought down by the Sacramento River alone and the balance by the San Joaquin River. It may be assumed that considerably larger quantities of debris than the average have been brought down during years of very large floods, perhaps as much as two or three times the average estimated amount. Under natural conditions, this debris was deposited in the channels and in the flanking overflow basins of the river systems, and especially in the lower portions of the channels where the gradients flattened out and the velocities decreased to such an extent that the loads of material were dropped. Large amounts of debris were deposited also in Suisun and San Pablo bays. These deposits in the river channels and upper bays formed shoals a:_d islands. The lighter materials deposited in the bays were transported by tidal currents toward the shores, gradually building up extensive areas of mud flats extending out for considerable distances from the shore line. ' The debris from natural erosion transported by the Sacramento and San Joaquin rivers w^as greatly augmented by the advent of hydraulic mining in California. This system of gold mining was started in the early fifties soon after the discovery of gold. Hydraulic-mining operations thereafter increased with rapid strides, reaching maximum proportions in the early eighties. In 1880, it is estimated by Wm. Ham Hall, former state engineer, that there was a total of over 53,000,000 cubic yards of gravel washed in the hydraulic-mining operations during that year alone. * Prof. Paper No. 105, "Hvdraulic-Mining Debris in the Sierra Nevada," G. K. Gilbert, U. S. Geological Survey, 1917. 154 DIVISION OF WATER RESOURCES The location of the auriferous gravels is shown on Plate XXXIII. The bulk of these gravels are situated within the drainage basins of the Feather, Yuba, Bear and American rivers. Smaller deposits are located on tributaries of the San Joaquin lliver from the ]\Iokelumne River as far south as the Tuolumne River. The larger operations were carried on in the drainage basins of the Yuba, Bear and American rivers. The scale of operations was much smaller on the San Joaquin River tributaries. The larger hydraulic mines, such as the Malakoff of the North Bloom- field Mining Company, North Columbia, Omega, Sailor Flat, Blue Tent, Scott's Flat, Quaker Hill, Red Dog, You-Bet, Dutch Flat, Gold Run, Iowa Hill and Michigan Bluff all lie within the Yuba, Bear and Ameri- can River basins and are famous in the annals of the h^'draulic-mining industry. The debris washed out by these hydraulic mines was discharged into the natural streams nearby and was gradually carried downstream into the lower portions of the river channels and into the bay. It was esti- mated by Gilbert * that the total amounts of debris discharged into the natural streams from h,ydraulic-mining operations amounted to 1,675,- 000,000 cubic yards in the period from 1850 to 1914. Of this total over 80 per cent, or about 1,400,000,000 cubic yards, is estimated to have been brought down by the Feather, Yuba, Bear and American rivers. It is thus seen that the estimated amount of debris brought down from these mining operations is nearly two and one-half times the estimated amount emanating from natural erosion of m^ountain, foothill and valley areas. Of the total amount of debris brought down by the two river systems from both natural erosion and hydraulic-mining operations during the period 1850 to 1914, inclusive, estimated by Gilbert at 2,375,- 000,000 cubic yards, the same authority estimated the distribution of the deposition of this material as of the year 1914 in accordance with the following tabulation : Million cubic yards Deposits within the Sierra Nevada 205 Piedmont deposits 520 ^„j^| Deposits in the channels of valley rivers 100 Deposits on inundated lands, including tidal marshes 294 Deposits in the baj'S 1,146 Deposits in the ocean 50 Total 2,375 It appears from Gilbert's estimates that nearly half of the total amount of debris brought down by the rivers during this period had been cari-ied into the bays by 1914, while only about 37 per cent still remained in the river channels. This tremendous increase in the load of debris carried by the streams in flood resulted in the creation of very serious conditions in the Sacramento Valley. The river channels were gradually filled with debris and choked up to such an extent that the larger floods overtopped the banks and low levees constructed by the early settlers and inundated large areas of farm lands, covering them in large part with debris which * Prof. Paper No. 105, "Hydraulic-Mining Debris in the Sierra Nevada," G. K. Gilbert, U. S. Geological Survey, 1917. VARIATION AND CONTROL OF SALINITY 155 destroyed growings crops and rendered the land useless at that time for farming. These conditions brought about a prompt response from the farmers of the Sacramento Valley, which took the form of several suits filed in the courts seeking to enjoin hydraulic-mining operations. This issue Avas finally settled by the decision in the famous suit of Woodruff vs. The North Bloomfield Mining Company, rendered on appeal to the Federal Circuit Court in 1884. By the decision of the court, the oper- ators of hydraulic mines were enjoined from discharging debris into the streams. After this decision was made no operations of large magnitude were continued and in about 1895 hydraulic mining was practically ter- minated. In 1893 the California Debris Commission Act was passed by Congress creating a commission of army engineers to take charge of the whole debris problem created hy hydraulic-mining operations and pro- hibiting and declaring unlawful hydraulic mining on the Sacramento and San Joaquin River systems, except under certain restrictions. This commission not only has charge of the regulation of hydraulic mining but also the preparation of plans and the construction of works for flood control and improvement and maintenance of navigation. As far as salinity conditions and this iuA^estigation are concerned, it is of particular interest to determine what the effect of hydraulic mining and the consequent abnormal silting of the river channels and upper bays has been upon the tidal prism and the magnitude of tidal flow and tidal action. The abnormal load of debris carried down from the hydraulic-mining operations was deposited initially in the channels of the rivers below the rim of the valley. In the early stages of the movement of debris downstream, the channels of the branch rivers such as the Yuba, Bear and American, were first filled with debris in the mountain sections. This debris gradually moved downstream each year in constantly increasing magnitude. The gradual filling of the channel of the main Sacramento River is best illustrated by the graph on Plate XXXV, ''Changes in Channel Bed of Sacramento River, 1841 to 1929," which shows profiles of the channel bed of the Sacramento River from the city of Sacramento to Suisun Bay, based upon the records of surveys made in different years from 1841 to 1930. For purposes of comparison, it is particularly fortu- nate to have the early profile of 1841, which is based on a survey made in that year and enlarged in 1850 by Wilkes and Ringgold. This is the best information available as to the natural level of the stream bed prior to hj^draulic mining. The next survey was made in 1878 and by that year the debris from hydraulic mining had already started to fill the river channels clear through to the bay. Later surveys in 1894, 1895, 3907, 1917, 1920, were made by the Federal and State governments and finally the last available survey in 1929 and 1930 by the Federal govern- ment. These data show the magnitude of the filling of the river chan- nels after hydraulic mining started until about 1894 and 1895, when the accumulation of debris reached maximum proportions in the channel from Sacramento downstream. It appears that the debris filled up the channel to a depth of ten feet or more for a considerable distance below Sacramento, the depth of filling in general decreasing at points farther downstream. Subsequent to 1895, the data indicate that the bed of the river channel has gradually lowered, due to the combined effect of scour by 156 DIVISION OF WATER RESOURCES floods, and dredging for reclamation development and channel improve- ments. Although the deepening of the channel has not been uniform in all portions of this stretch of the river, the records evidence a positive tendency toward a lowering of the channel bed. Up to 1930, the data from the available surveys indicate that the main channel of the Sacra- mento River from Sacramento to the lower end of Grand Island has been deepened an average of about five feet below the levels of 1895. These changes in the channel of tlie Sacramento River had a material effect upon the water level in the channel and the extent and magnitude of tidal action. Table 21 summarizes the record of mini- mum and maximum seasonal gage heights of the Sacramento River at Sacramento from 1849 to 1929, as obtained from the U. S. AVeather Bureau records published in government reports. The gage heights are referred to a gage established in 1856, the zero of which is approxi- mately mean sea level (U. S. G. S. Datum). As sho^vn in this record, the low water level for the season in early years was as low as zero on the gage. Following the advent of hydraulic mining, the elevation of low water gradually increased from year to year until it reached a maximum in 1890 to 1895 of about seven to eight feet. At about this time, tidal fluctuation at Sacramento is reported to have ceased. Where under natural conditions the tidal range at Sacramento was about two feet, it was gradually decreased from 1860 to 1871 to about one foot and by 1883 is stated to have entirely disappeared. It is reported that the limit of tidal action at about this time was over ten miles below the city of Sacramento. Since 1896 the low water level at Sacramento has gradually lowered until at the present time it is within one-half foot to one foot of the low level during the days before hydraulic mining. This low level, of course, is materially affected by the quantity of the summer and fall stream flow which, because of large diversions from the river in recent years, is probably very materially less than in the fifties and sixties. However, the fact that the elevation of low water at Sacramento has decreased six or seven feet during the last 30 years is a fairly good index of the cleaning out of the channel by the combined action of stream erosion and dredging operations. This lowering of water level at Sacramento may also be assumed to be an index of a proportional amount of lowering, although of smaller amount, at points farther downstream. At the same time the effect of tidal action and the tidal limits have advanced upstream during this 30-year period until the range of fluctuation and the limits of tidal action evidently are at present about the same as in the earlj^ days before hydraulic mining. Under the maximum conditions of channel filling by hydraulic- mining debris, there is no question but what there was some effect upon the magnitude and extent of tidal action. Other things being equal, the tidal flow into the tidal basin of the delta was probably diminished during this stage of debris-loaded channels. As will appear from the discussion hereafter, such a change in tidal flow would have had some effect upon the advance and retreat of salinity. However, con- ditions in the delta and river channels have been restored practically to their original natural state, at least as to any limiting effect on the tidal prism is concerned. Therefore, it appears evident that the salinity con- ditions in the upper bay and delta channels during recent years have not been affected by or connected in any way with the deposition of debris emanating from past operations of hydraulic mining. 20 10 -10 H -20 -30 -40 -50 -60 E 4- (B O Q UJ CO 20 H 10 -10 tt) -20 C -30 -50 -60 ^^ I2( -10 -20 -30 -AO -50 -60 Q d ui ; -70 24 80995 — p, -rS- -r-il Tjtew *«.oJ ■■n' "ui . li- I I I t as at 1 r . •" I 1 ^ ^ 6 O) — i 1 i 1 i i i 1 oei 0«^f 1 — r— I r 1 — ^— 1 — r anil T9T6W woJ'"* i . .1 ers eas 156 DIVISION OF WATER RESOURCES floods, and dredging for reclamation development and channel improve- ments. Although the deepening of the channel has not been uniform in all portions of this stretch of the river, the records evidence a positive tendency toward a lowering of the channel bed. Up to 1930, the data from the available surveys indicate that the main channel of the Sacra- mento River from Sacramento to the lower end of Grand Island has been deepened an average of about five feet below the levels of 1895. These changes in the channel of the Sacramento River had a material effect upon the water level in the channel and the extent and magnitude of tidal action. Table 21 summarizes the record of mini- mum and maximum seasonal gage heights of the Sacramento River at Sacramento from 1849 to 1929, as obtained from the U. S. AVeather Bureau records published in government reports. The gage heights are referred to a gage established in 1856, the zero of which is approxi- mately mean sea level (U. S. G. S. Datum). As shown in this record, the low water level for the season in early years was as low as zero on the gage. Following the advent of hydraulic mining, the elevation of low water gradually increased from year to year until it reached a maximum in 1890 to 1895 of about seven to eight feet. At about this time, tidal fluctuation at Sacramento is reported to have ceased. Where under natural conditions the tidal range at Sacramento was about two feet, it was gradually decreased from 1860 to 1871 to about one foot and by 1883 is stated to have entirely disappeared. It is reported that the limit of tidal action at about this time was over ten miles below the city of Sacramento. Since 1896 the low water level at Sacramento has gradually lowered until at the present time it is within one-half foot to one foot of the low level during the days before hydraulic mining. This low level, of course, is materially affected by the quantity of the summer and fall stream flow which, because of large diversions from the river in recent years, is probably very materially less than in the fifties and sixties. However, the fact that the elevation of low water at Sacramento has decreased six or seven feet during the last 30 years is a fairly good index of the cleaning out of the channel by the combined action of stream erosion and dredging operations. This lowering of water level at Sacramento may also be assumed to be an index of a proportional amount of lowering, although of smaller amount, at points farther downstream. At the same time the effect of tidal action and the tidal limits have advanced upstream during this 30-year period until the range of fluctuation and the limits of tidal action evidently are at present about the same as in the early days before hydraulic mining. Under the maximum conditions of channel filling by hydraulic- mining debris, there is no question but what there was some effect upon the magnitude and extent of tidal action. Other things being equal, the tidal flow into the tidal basin of the delta was probably diminished during this stage of debris-loaded channels. As will appear from the discussion hereafter, such a change in tidal flow would have had some effect upon the advance and retreat of salinity. However, con- ditions in the delta and river channels have been restored practically to their original natural state, at least as to any limiting effect on the tidal prism is concerned. Therefore, it appears evident that the salinity con- ditions in the upper bay and delta channels during recent years have not been affected by or connected in any way with the deposition of debris emanating from past operations of hydraulic mining. "^t^rC- o 3 r^~0 T £ :-■ 0) a I, -J (vlo rn T r 44 ■" J_L J L i_L est 1 I ..I , 1 . ^ r ■ i _i.T_ .- nn ■ 3S' VARIATION AND CONTROL OF SALINITY 157 TABLE 21 ANNUAL MINIMUM AND MAXIMUM RIVER STAGES OF SACRAMENTO RIVER AT SACRAMENTO 1849-1929 L< Year Gage heights, in feet Year Gage heights, in feet Minimum stage Maximum stage Minimum stage Maximum stage 1849 —0.6 —0.1 —0.1 2.1 0.3 1.9 1.3 1.6 0.2 1.0 1.9 1.3 18.8 20.2 9.8 21.7 19.4 20.2 20.3 12.4 18.2 18.9 19.0 15.2 21.8 24.0 24.1 1895 8.3 8.5 8.3 7.1 7.4 7.6 7.2 6.9 7.0 8.2 6.3 6.8 7.3 5.3 5.5 5.1 5.5 4.1 2.6 4.2 4.0 2.9 2.7 0.9 0.7 —0 3 1.2 1.3 0.8 -0.2 0.8 0.1 0.8 0.7 0.8 26.6 1850 1851 1896. 1897 26.7 24.2 1852 1898 16.7 1853 -- . 1899 1900 . 24.2 1854 27.0 1855 ■ 1901 28.2 1856 1902 28.2 1857 1903 - 27.6 1858 1904 27.9 1859 1905 22.0 1860 1906 27.4 1861 1907 27.2 1862 1908 20.4 1867 1909 29.6 1869 2.9 4.6 4.3 7.1 5.2 5.3 5.8 7.4 6.4 6.5 6.5 7.5 7.3 7.5 7.2 7.1 7.0 9.3 7.4 7.0 7.6 7.5 1910 22.8 1874 19.1 22.2 24.7 18.1 26 23.7 24.4 26.5 21.2 20.7 24.6 23 9 25.6 20.5 20.0 27.0 24.6 26.9 28.6 26.5 22.6 1911 26.9 1875 1912 16.7 1876 1913 17.9 1877 1914 27.8 1878 1915 26.8 1879 1916 25.9 1880 1917 26.4 1881 1918 20.6 1882 1919 - 28.6 1883 1920 23.8 1884 . 1921 26.3 1885.. 1922 25.4 1886 .... -- . '1923 21.3 1887 51924 18.4 1888 fl925 28.0 1889 . tl926 24.8 1890 11927 27.4 1891...: '1928 29.5 1892 1929 23.2 1893 1894 Note.- Data for periods 1849 to 1879 ail 18?3 to 1833 fron -epart of Con-ni?3ioner of Public Works 1894-95; for periods 1879 to 1888 and 1891 to 1929 froai re.)ort! o.i Daily River Stages on Important Rivers in United States, by U. S. Weit'aer Bureau. Growth and Effect of Reclamation in Delta — Reclamation development in the delta of the Sacramento and San Joaquin rivers was started in the fifties. The first work was done on a very small scale by indi- viduals who put up small levees, usually by hand labor, to partially reclaim small acreages. Following the adoption of the ''Arkansas Act" by the United States Congress in 1850, which provided for Federal grant of swamp and overflow lands to the various states, the State Legislature passed several acts beginning in 1855, consummating in the creation of a Board of Swampland Commissioners in 1861. This act provided for the sale of swamp lands by the State to individuals who would undertake to reclaim the lands purchased. From the time of the passage of this act, reclamation development increased rather rapidly. The works required were of considerable magnitude and hence it soon became the usual practice for groups of individuals to band together in a cooperative organization to cany out the required construction work. Swampland or Reclamation districts were formed in large numbers immediately after the passage of the Swampland Act 158 DIVISION OF WATER RESOURCES in 1861. District No. 1 comprised the whole of the American Basin between the American and Bear rivers; District No. 2, the Sacr.imento Basin between the American and Mokelumiie rivers; and District No. 3, Grand Island. Considevablo work was started after the forma- tion of these districts but the magnitude and cost of the work was very much greater than was first estimated by the ])romoters. Frequently the initial group of promoters failed to complete the reclamation works. For the most part, a considerable number of years, accompanied often by changes in ownersliip and management, were required before reclama- tion was completed. In some cases low levees were fir.st completed affording partial protection, at least for conditions of low stream flow, from tidal fluctuations. During winter floods tliese partially reclaimed lands would be submerged and often considerable portions of the levees were destroyed. A search of all available records and sources of information was made for the purpose of ascertaining the date at which the various reclamations were completed within the delta area. These have included all the records in the office of the State Reclamation Board, State and Federal reports, county records, early maps and neAvspapers, and information from reclamation district officials and early settlers in the delta. It has been found that, in many cases, there is considerable doubt as to the exact time when levee reclamation may be considered to have been completed. From the standpoint of its possible effect on the tidal basin, effort has been made to determine the date when each reclamation development completed its levees to a sufficient extent to permanently eliminate the area thus reclaimed from the tidal basin. For those areas which, after first being reclaimed, were later flooded again by breaks in the levees, the last date of complete reclamation after the breaks were repaired has been taken. TABLE 22 GROWTH OF RECLAMATION IN SACRAMENTO-SAN JOAQUIN DELTA 1860-1930 Decad? Area reclaimed, in acres .\ccutnulated area reclaimed, in acres 1860-1870 . , - 15,000 92,000 70,000 58,000 88,600 94,000 24,000 i,5,ono 1870-1880. . 107,000 1880-1890 ... . 177,000 1890-1900 - 235,000 1900-1910 323,(i00 1910-1920 417,600 1920-1930 - 441,600 Note.— Prior to 1890 reclamation was of a tempsrery nature and its exact extent small but indefinite. The compiled data on growth of reclamation are shown in Table 22 and grai)hically illustrated on Plate XXXVl, "Growth in Reclamation Development in the Sucramento-San Joaquin Delta." The progressive growth of reclamation is also shown on Plate XXXIV, on which is depicted in various colors the area reclaimed during successive decades from 1860 to 1930. The data show that there was but little acrea^ actually reclaimed prior to 1870. During the decade 1870-1880 a very substantial development took place, over 90,000 acres being reclaimed VARIATION AND CONTROL OF SALINITY 159 I'LATE XXXVI 1/5 o ABO AOO 350 300 CO ■o d (0 1/5 250 O CO 4) 200 E JO o CC 1850-70 1870-80 1880-90 1890-1900 1900-10 1910-20 1920-30 Decade GROWTH JN RECLAMATION DEVELOPMENT IN THE SACRAMENTO - SAN JOAQUIN DELTA 160 DIVISION OF WATER RESOURCES From 1880 to 1900, the rate of development fell off somewhat, there being less than 130,000 acres reclaimed. However, from 1900 to 1920, an additional area of over 180,000 acres was reclaimed. The maximum area reclaimed in any decade from 1860 to 1930 was 94,000 acres during the period 1910-1920. It is important to note that the bulk of the reclamation development was completed prior to 1920. Only about 24,000 acres have been added during the last decade. The reclamation of the delta has resulted in a change in the total area and volume of the delta tidal basin. Under natural conditions, the gross area potentially embraced within the tidal basin above the confluence of the Sacramento and San Joaquin rivers (see Plate XXXIV) at mean tide level during the low water season was about 300,000 acres. However, all of this gross area was not submerged by the tidal fluctuation. The lands along the banks of the natural channels were built up by deposits of sediment from the overflow of the streams during flood, so that the rims of the islands were consider- ably higher in elevation than the interior of the islands. In many cases the banks were high enough to keep out the tidal waters during the period of low stream flow in the summer and fall. Within the Sacra- mento Delta, pronounced ridges were built up by silt deposits along the banlcs of the river and branch channels and, thus, considerable areas of land lay above tidal levels in tlie period of low stream flow. There is no definite or complete information available as to the elevation of most of the lands in the delta before reclamation or as to what areas were submerged by tidal fluctuation. The available information as to elevation consists of the topographic maps of the United States Geo- logical Survey compiled from surveys which were made after the delta lands were reclaimed. It is well knoAvn that the peat lands comprising most of the San Joaquin Delta and the lower Sacramento Delta have subsided materially since their reclamation and, hence, the elevations shown on these topographic maps for the peat lands can not be assumed to show the level of the lands under natural conditions prior to reclama- tion. It is stated by individuals fnmiliar with conditions in the San Joaquin Delta prior to reclamation that considerable areas in the San Joaquin Delta were not submerged by tidal fluctuations in the low water season, although the government topographic maps indicate that these areas would have been submerged at mean higli or high tidal stages. Therefore, it is im])ossible to make an estimate of the area submerged by tidal fluctuation under natural conditions before reclamation but it appears that a substantial portion of the gross area of 300,000 acres potentially within the delta tidal basin w'as submerged at least by the high tides. In connection wdth the reclamation of lands in the delta, there has been a considerable alteration of the open channels. Some of the smaller natural channels have been closed, but many new artificial channels have been created by dredge cuts for levee construction. Most of the main natural channels have been widened by the excavation of levee material. New channels have also been created along the San Joaquin River by the Federal Government for improvement of naviga- tion. All of this work has probably increased the area and volume of open channels within the tidal prism. However, the simultaneous VARIATION AND CONTROL OF SALINITY 161 leveeing-off of lands wliich were originally submerged by tidal flow probably has more than counterbalanced the increase in open channels. At the present time the area of the tidal basin is about 39,000 acres. Assuming that the tidal levels and fluctuations in the delta under natural conditions were about the same as at present, the tidal volume within the limits of mean tidal range probably was somewhat greater under natural conditions than the present tidal volume of about 120,000 acre-feet. However, it can not be inferred that the tidal flow into the delta before reclamation was very materially greater than the present tidal flow. The original natural conditions within the delta were entirely different than at present. The lands subject to tidal submergence were covered largely with a thick growth of tules and similar aquatic vegetation. It is reasonable to assiune that the move- ment or flow of water onto and away from the lands subject to sub- mergence would have been substantially delayed by the retarding effect of this vegetation. Hence, the flow of tidal waters into and out of the original tidal basin, taken as a whole, undoubtedly would have taken place with a different rate and character of tidal movement than occurs at present. It appears that the actual tidal flow into the delta tidal basin, under original natural conditions, could not have been much greater in magnitude than the present tidal flow. The historical infor- mation previously presented in Chapter II as to salinity conditions, including data as far back as 1775, again in 1841 and also in the sixties and seventies, shows that the invasion of saline water into the delta, under natural conditions before reclamation, extended only a short distance above the confluence of the Sacramento and San Joaquin rivers even in dry years. If the original tidal flow had been materially greater than the present tidal flow, it would have resulted in a much greater magnitude of saline invasion than is known to have occurred. The reclamation of the lands in the delta has eliminated a large area of aquatic vegetation such as cat-tails and tules which consume three to four times as much water as the crops which are now grown on these reclaimed lands. As a result, it appears probable that the consumption of water within the delta has been decreased by reclama- tion development, and that a greater proportion of the stream flow entering the delta now reaches the lower end of the delta to repel saline invasion than before reclamation. Based upon the foregoing considerations, it appears reasonable to conclude that the reclamation of lauds in the delta, by decreasing tidal flow and reducing consumption in* the delta, has had the effect of decreasing to some extent the degree and extent to which saline invasion would have occurred during the last decade, if these lands had not been previously reclaimed. In other words, with the same stream flow into the delta as during the period 1920 to 1929, salinity conditions probably would have been worse in the delta if the lands had not been reclaimed. The reclamation of the marsh lands adjacent to Suisun Bay also has had the effect of decreasing tlie magnitude of tidal flow into Suisun Bay to some extent and hence reducing the tendency of saline invasion into the Suisun Bay channels and tending to delay the advance of salinity through Suisun Bay to the delta. Effect of Recent Changes in Delta Tidal Basin — There are certain changes during the last ten to fifteen years in connection with reclama- 11—80995 162 DIVISION OF WATER RESOURCES tioii and flood control works within the delta which have had the effect of increasinfi" tidal flow into the delta. These changes are of im])ortance, in that they liave been a contributin-) u u o z u u H u CO > H Z < o CO o Ml H ?n /4 u -n s *-> < o q: 4-> C3 u E n < (0 3 Q ta ^ c 8. 3 0) Jan. 16 to Feb. 13, 1930 Jan. 18 to Feb. 24. 1930 .Tan. 18 to Feb. 11. 1930 o CO ►-a O OOOOOOOOIOTOOOOO eococccococococic-icocococoeo OS OS 3i C3i Oi Oi - CI Oi Oi Ci 05 OT O May 6 to July 1 Jan. 21 to Mar. 3 May 1 to Sept. 30 July 28 to Sept. 30 May 1 to June 30 May 1 to July 1 Oct. 10, '29 to Jan. July 1 to Oct. 31 July 7 to Oct. 31 April 1 to July 30 April 1 to July 30 Aug. 9 to Aug. 31 April 1 to May 18 April 1 to July 30 Mean time interval for all tidal phases Minutes.. Hours « o — o — - coco»oc>i-<» O^ 03 O) .»j •»> .*a .»3 f). O O « O Qj OOOOc^ o o o o o .*A -^A -^A -«J -t^ ,_! ,-H ,-1 .— I CO ■^■^ Tt4 cocao ■^lOUD t^ O Tt* ■^ -^ ^C Oi lOiX) COOO'-H •^ -^ ■^ to Oi CO"^-* lOOO •<*«iCiO t^o CO-^Tf Uti t^ CO CO CO »o t^ rj< lO lO !>. OS CO'Tj<^iCO0 CO CO ■<*< lO !>• •^ifllOb^ OS :e« O^ OS OS OS Q) O) OS OS M . .^Jt .fc^ -tJ . " " 0? " « « S) " OOcoOcQOJcoO oooooooo ^iOtOeOt^t^tsoO lOU^CDCOt^OOOS^H TPW5iO«Dt^t^OOO iCt^lr^t^OSOOOCC '^icuricDt^t^ooo --t--t--OSO ■^•^lOir^soeot^Os CO-*'^loincCi:D0O io»o o I CO « " «, *> .2 S.2 ti 5 ^ ja-2 £, id °"!^ ^ o o a a o O I 168 DIVISION OF WATER RESOURCES The advance of tlie tide in the tidal basin of San Francisco Bay and i)arti('nlarly in tlip upper bay and delta channels represents a progressive wave movement. The crest of this wave advances progres- sively upstream, and the culmination of low and high waters takes place at constantly increasing time intervals after the occurrence of the same at the Golden Gate, as the distance from the Golden Gate is increased. In a tidal movement, it is necessary to distinguish clearly between the velocity of current induced and the progression or rate of advance of the tide. In the former case, reference is made to the actual speed of a moving particle of water while, in the latter case, reference is to the rate of advance of a particular tidal phase or the velocity of propagation of the progressive wave. In general, the rate of advance of a tidal phase or the progressive wave is many times greater than the actual velocity of the current induced by the tidal movement. It does not necessarily follow that there is a relation between the velocity of tidal current in any channel section and the rate of advance of the tide in this same section. The existence or non- existence of a velocity of tidal current can not be inferred alone from a known rate of advance of the tide. The velocity of tidal current or the actual speed with wliich the particles of water are moving past any fixed point depends upon the volume of water which passes the given point and the cross-section of the channel at that point. The velocity of the tidal current is, therefore, independent of the rate of advance of the tide. The rate of advance of the tide in any given channel depends upon the type of the tidal movement. For the upper bay and delta channels the tidal movement takes the form of a progressive wave which moves approximately in accordance witli the following theo- retical formula: r = yid" in which r = rate of advance of the tide in feet per second. g = acceleration of gravity in feet per second squared, d = the depth of the waterway in feet.- This formula becomes r = 3.87 V"~d" with r expressed in miles per hour. Based upon the data on time of occurrence of tidal phases as pre- viously presented, comi)utations were made to determine the rate of advance of the tides in the channels of the Sacramento and San Joa- quin rivers. The results of this study are sliown on Plate XXXVII, "Rate of Advance of Tides in Sacramento-San Joaquin Delta Chan- nels." On this plate the curve plotted from the theoretical formula is shown on the lower part of the diagram and, in addition, a separate curve is shown for the Sacramento River and San Joaquin River channels. The.se curves are drawn through ]>lotted points determined from a computation of the difference in time of occurrence of tidal phases and channel depths. Thus for the channel section from CoUins- ville to Three INIile Slough on the Sacramento River, the difference in time of the occurrence of tides as shown on Plate XXXIV is hours VARIATION AND CONTROL OF SALINITY 169 PLATE XXXVII 4 8 12 16 Rate of advance of tide in mi 20 24 ies per hour RATE OF ADVANCE OF TIDES IN SACRAMENTO -SAN JOAQUIN DELTA CHANNELS no DIVISION OF WATER RESOURCES and 32 minutes over a channel distance of 9.2 miles, from which the actual rate of advance of the tide is computed as 17.2 miles per hour. This channel section has an average depth of 35.5 feet. In a similar manner all of the ])oints on the dia<;ram were computed and plotted. The difference hetween the curves determined for points along the Sacramento River and San Joaquin River channels probablj'" is due to the variable character and com])osition of the net work of branch cliannels whicli affect the tidal movement along these main channels of the basin. The rate of advance in relation to channel depth as shown by the.se curves indicates that the movement is similar to a progressive wave. These curves have been used for the purpose of interpolating points of equal time of occurrence of tidal phases between tide gage stations. These data have been especially important and essential in the com- pilation of the maximum effective volume in the tidal prism of the delta and Suisun Bay. Tidal Volumes in Delta and Suisnn Bay — The maximum effective volume of the tidal prism in the delta of the Sacramento and San Joa- quin rivers and in Suisun Bay comprises the total volume between the extreme limits of tidal range from lower low water to higher high Avater. For convenience, this volume is referred to as the "tidal volume." For the purposes of this investigation, the limits of tidal range considered are for the period of low stream floAV during summer and fall months, covering the advance and retreat of salinity. These tidal volumes have been computed separately for the tidal basin in the delta proper above the confluence of the Sacramento and San Joaquin rivers at Collinsville (Chain Island) and for Suisun Bay from Army Point to Collinsville. The results of tlie computations are shown on Plate XXXVIII, "Accumulated Tidal Volume in Sacramento and San Joaquin Delta Channels," and Plate XXXIX, "Accumulated Tidal Volume in Suisun Bay." The tidal volume in the delta has been divided as between the Sacramento Delta and the San Joaquin Delta. It should be noted that tidal volume is distinct from total storage volume in the basin, the latter being the total volume in the basin from the bed of the channel to the water surface and the former includ- ing only the volume between the limits of tidal range. The tidal volumes of the delta channels have been computed from the surveys of the United States Army Engineers. These surveys have been made over a considerable iieriod of years. Some are far from up to date, particularly for portions of the channels in the San Joaquin Delta, such as Old River and IMiddle River and the connecting channels thereof, and the lower San Joaquin River below the mouth of the ]\rol\e]unnie River, which were surveyed in 1908. For the upper San Joaquin River from the mouth of the Mok(>lunine River to Stockton, the rather recent surveys made in connection with the Stockton Ship Canal are available. There are similar variations in the dates of surveys on the Sacramento River. Certain ])ortions, especially the lower end of the Sacramento River, have been surveyed during 1929 and 1930 and other portions during the previous ten years. In all eases, however, the latest survey data have been used in the compilation of tidal volumes. PLATE XXXVIII 15 1 - E OF TWO-MILE INCREMENTS TABLE OF TWO-MILE INCREMENTS :ramento river channels SAN JOAQUIN RIVER CHANNELS ROM VOLUME IN VOLUME IN ACRE-FEET MILES FROM VOLUME IN VOLUME IN ACRE-FEEt| en o . c - END ACRE- FEET BETWEEN ELEV. PER FOOT OF DEPTH LOWER END OF ACRE-FEET BETWEEN ELEV. PER FOOT OF DEPTH | BELOW ABOVE BELOW ABOVE UNO -3.0 & '7.0 ELEV. ♦1.0 ELEV. +1.0 CHAIN ISLAND -3.0 &' 7.0 ELEV. ♦ 1.0 ELEV. 1 1.0 U.S.G.S. DATUM U.S.G.S. DATUM U.S.G.S. DATUM U.S.G.S. DATUM U.S.G.S. DATUM U.S.G.S. DATUM 3 *1\ ") 10,100 900 1,083 14,500 1,200 1,617 8,700 775 933 27,600 2.175 3,150 «3p 7,700 625 867 8.600 775 917 2; 8,000 750 834 6,600 600 700 o : 8,200 800 833 16 18 20 ?7 6,600 600 700 ^l 9,000 775 984 7.900 750 817 12,100 1.075 1,300 8,900 725 1,000 7,700 600 883 11.800 812 1.425 ^ 4,100 325 467 2lt 26 28 30 'K 7 11,800 1,000 1,300 tt 3,200 300 333 7.80O 637 875 9 3.400 300 367 9.700 875 1,033 3,400 300 367 13,000 1,000 1,500 5 2,100 200 217 17,300 1,262 2.041 C 4 1,600 150 167 c. "XL 14,000 1,237 1,508 1.700 150 183 OH 36 \ ft 14,900 1,075 1,767 O 8 D 1.800 150 200 14.500 1,075 1,700 1.700 150 183 J O 40 47 18,800 1,450 2,167 1.500 125 167 10.800 725 1,317 1,200 100 133 44 8,900 725 1,000 6 ^2 C * i — 2 C 4 1.000 100 1 17 46 48 SO 52 54 56 58 60 62 64 66 68 70 72 74 7,700 650 850 1.200 100 133 3,200 300 333 1.600 150 167 2,700 237 292 1,100 100 1 17 2,900 187 358 1.100 100 i 17 2.000 162 225 1,100 100 1 17 2.100 187 225 900 75 too 1.400 137 142 1,200 100 133 1.400 100 167 1,000 75 1 17 500 37 58 liOOO 75 133 600 SO 67 900 75 100 300 25 33 1,000 75 1 16 300 50 1,000 50 133 300 50 800 75 83 300 50 500 25 67 ISO 25 ISO 25 V «oo ff o «^ CO ACCUMULATED TIDAL VOLUME IN SACRAMENTO AND SAN JOAQUIN DELTA CHANNELS : 80995 1 170 DIVISION OF WATER RESOURCES and 32 minutes over a channel distance of 9.2 miles, from which the actual rate of advance of the tide is computed as 17.2 miles per hour. This channel section has an average depth of 35.5 feet. In a similar manner all of the i)oints on the diaj>ram Avere computed and plotted. The difference between the curves determined for points along the Sacramento River and San Joaquin River channels probablj^ is due to the variable character and composition of the net work of branch channels Avhich affect the tidal movement along these main channels of the basin. The rate of advance in relation to channel depth as shown by these curves indicates that the movement is similar to a progressive wave. These curves have been used for the ])ur])ose of interpolating points of equal time of occurrence of tidal phases between tide gage stations. These data have been especially important and essential in the com- pilation of the maximum effective volume in the tidal prism of the delta and Suisun Bay. Tidal Volnmes in Delta and Suisun Bay — The maximum effective volume of tlie tidal prism in the delta of the Sacramento and San Joa- quin rivers and in Suisun Bay comprises the total volume betAveen the extreme limits of tidal range from lower low water to higher high water. For convenience, this volume is referred to as the "tidal volume." For the purposes of this investigation, the limits of tidal range considered are for the period of low stream flow during summer and fall months, covering the advance and retreat of salinity. These tidal volumes have been computed separately for the tidal basin in the delta proper above the confluence of the Sacramento and San Joaquin rivers at Collinsville (Chain Island) and for Suisun Bay from Army Point to Collinsville. The results of the computations are shown on Plate XXXVIII, "Accumulated Tidal Volume in Sacramento and San Joaquin Delta Channels," and Plate XXXIX. "Accumulated Tidal Volume in Suisun Bay." The tidal volume in the delta has been divided as between the Sacramento Delta and the San Joaquin Delta. It should be noted that tidal volume is distinct from total storage volume in the basin, the latter being the total volume in the basin from the bed of the channel to the water surface and the former includ- ing only the volume between the limits of tidal range. The tidal volumes of the delta channels have been computed from the surveys of the United States Army Engineers. These surveys have been made over a considerable period of years. Some are far from up to date, particularly for portions of the channels in the San Joaquin Delta, such as Old River and Middle River and the connecting channels tliereof, and the lower San Joarpiin River below the mouth of the IMokelumne River, which were surveyed in 1908. For the upper San Joa(|uin River from the moutli of the ^Fokelumne River to Stockton, the rather recent surveys made in connection with the Stockton Ship Canal are available. There are similar variations in tlie dates of surveys on the SacranuMito River. Certain ])ortions, esjieeially the lower end of the Sacramento River, have been surveyed during 1929 and 1930 and other portions during the previous ten years. In all eases, however, the latest survey data have been used in the compilation of tidal volumes. PLATE XXXVIU S 160 SACRAMENTO RIVER CHANNELS 1 1 1 1 1 1 1 1 1 Till 1 1 1 1 1 1 1 1 Between elevations -3.0 and 1 1 1^ 1 1 1 1 1 1 1 '7.0 feet U.S.G.S. datum 1: 1- TABLE OF TWO-MILE INCREMENTS SACRAMENTO RIVER CHANNELS TABLE OF TWO-MILE INCREMENTS SAN JOAQUIN RIVER CHANNELS ands of acre o - : y ^ _ MILES rPOM LOWER END OF CHAIN ISLAND volume: in acbe-feet between elev. -3.0 &«7.0 U.S.G.S. DATUM VOLUME IN ACRE-FEET PER FOOT OF DEPTH MILES FROM LOWER END OF CHAIN ISLAND VOLUME IN ACRE-FEET VOLUME IN ACRE-FEET PER FOOT OF DEPTH 3 9 or, BELOW ABOVE ELEV. ♦1.0 ELEV. +1.0 BETWEEN ELEV, -3 0i>70 U-S.G.S DATUM BELOW ABOVE ELEV '1.0 ELEV-' 1.0 U.SGS DATUM U5.6i. OATUII £ 80 "i >> 11 ^ 1 ySetween elevations -3.0 and* 1.0 feet U.S.G.S. datum - U.S G.S. DATUM J.S.G.S. DATUM 03 1^ — a- V i 1 J 1 1 1 1 1 1 1 1 1 1 1 , ill 1 1 i l.L_ 1 1 1 1 1 1 1 1 1 1 1 1 E 1 1 1 ll 1 1 1 1 1 1 1 1 1 1 1 1 1 10 1 1 1 ll 1 1 1 1 1 (/) K ) 15 20 25 30 35 40 45 50 55 60 65 70 75 Distance in miles from lower end of Chain Island near Collinsviile SAN JOAQUIN RIVER CHANNELS 80 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 i^r 1 1 1 T 1 1 Till 1 1 r 1 1 1 1 1 Till 1 1 1 1 - ^ -^ ^ 200 - Bei ween elevat ons -3.0 ane '7.0 feet U S.G.S. datur ■/ T3 c to o _ / E - ^ y ^ 120 ■ > - 1" C -J ,^ ^ 1 ^ Be tween eleva ions -3.0 an )• 1.0 feet I SG S dat jm, c to _ O y m 1 w -1 1 1 o lu _^ >> 1 •3- c CO CO AG ACCUMULATED TIDAL VOLUME IN ^ CI < l 1 1 1 1 1 1 1 1 1 1 1 1 r 1 ii 1 1 ,1 1 1 1 1 1 1 1 1 tc a: III, 1 1 1 1 1 1 1 1 1 1 1 1 % Q 1, 1 1 1 3 1 3 15 20 25 30 35 40 45 50 55 60 65 70 75 Distance in miles from lower end of Chain Island near Collinsviile 80 SACRAMENTO AND SAN JOAQUIN DELTA CHANNELS mj99b — p. 170 ^ARDAa H ■ },;n •un ni oon&l2iU 1 71 .q~ VARIATION AND CONTROL OF SALINITY 171 PLATE XXXIX o 1 /^ J t.\J 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I I I i - Between elevations "3,0 and*50 1 1 1 1 - feet US6S datum - _ 1 --.^ r ■7 O A / O V E fl5 - 3 ; CO * ~ ^ 60 c 1 o -1— ~ 1 5- c - 1 (U - 1 SS - a> 1 120 c ^ * * i i 3 l 1 j mm o -o 1 1 J ^ 1 > Hea 1 / ./ I - > // & f// 0> l- E // >^ K/ < ? i 1// " /y oB O °3 W.y^ 1 1 : 1 1 1 ; 1 1 1 35 40 45 50 5 5 Distance in miles from Golden Gate TABLE OF INCREMENTS ABOVE ARMY POINT ABOVE BAY POINT VOLUME IN VOLUME IN ACRE-FEET VOLUME IN VOLUME IN ACRE-FEET MILES ACRE-FEET PER FOOT OF DEPTH ACRE-FEET PER FOOT OF DEPTH FROM GOLDEN GATE BETWEEN ELEV - 3,0 8i . 6,0 BETWEEN ELEVATIONS BETWEEN ELEV. BETWEEN ELEVATIONS -3.0 a t 3.0 1 *i.O 8i»6.0 -3O&<-60 -30 a +3.0 ♦30 at 60 US.G.S DATUM lUS.G.S, DATUM U,S.G.S DATUM USG.S.DATUM U.S.O.S. DATUM US.GS. DATUM 33.8 34.0 360 38.0 1 ^ 1 1933 195 255 22418 2221 3031 31969 3122 441 1 33928 3530 4250 » 1092 • 116 • 132 400 42.0 38876 4195 4569 21890 2 338 2 621 'Volume above mile 39.9 49385 5274 5914 22937 2480 2 685 44.0 46 48,0 50.0 50,3 54III SS24 6989 24337 2 595 2922 3 1520 2S30 4846 16 534 1 707 2098 30857 2830 4626 15342 1 582 1951 46:9 425 694 2302 23:" 293 A CCUMULATED TIDAL VOLUME IN SUISUN BAY \ 172 DIVISION OF WATER RESOURCES The computations of tidal volume in the delta are of a tedious and voluminous nature, involvino* some 550 miles of channels. Volumes within the tidal ranf>e were first computed for successive segments of each channel from the channel cross sections on the survey maps and these volumes were then accumulated with distance from the lower to the upper end of each channel. The total tidal volume for the Sacra- mento and San Joaquin Delta tidal basins was then accumulated separately for each basin, progressing upstream from the confluence of the rivers at Collinsville (Chain Island) to the upper limits of the tidal basin. In this progressive accumulation, the distance in miles from the mouth of the river up through each basin was measured along the main channels, as shown on Plate XXXIV. The volumes in the branch channels were accumulated with the volumes in the main chan- nels on the basis of equal time of occurrence of tidal phases. Thus, the | volume in any branch channel was accumulated with the volume in the ' main channel up to points having an equal time of occurrence of tide. By this method, the volume of the tidal basin was accumulated in the same manner as the basin is filled or emptied by tidal waters. The accumulated tidal volumes for both the San Joaquin and Sacramento River cliannels have been computed for the tidal volume between elevations — 3 and + 1 and between elevations — 3 and + 7,. U. S. G. S. Datum. The tabulations on Plate XXXVIII summarize, by j two miles increments, the tidal volumes in acre-feet and, in addition, the variation of tidal volume per foot of depth for each zone between elevations — 3 and + 1 and elevations + 1 and -\- 7. For the tidal volume in Suisun Bay, the hydrographic survey made in tlie sjiring of 1930 b.y the United States Army Engineers was used. The compiled data are shown on Plate XXXIX. The tidal volumes between elevations — 3 and -f- 3 and elevations — 3 and + 6, U. S. G. S. datum, were progressively accumulated from the lower end to the upper end of the basin. The distance in miles along which the accumulation was made was measured along a median line from Army Point to the mouth of the river, as shown on Plate XXXIV. The accumulation of the volumes for the bay proper and for the branch channels was made in the same manner as in the case of the delta channels in proportion to the advance of the tide. Tidal Pris7n Volumes in Delta and Svisnn Bay — The actual changes in volume in the tidal prism of the delta and Suisun Bay between suc- cessive tidal phases vary with the range of the tide and include only a portion of tlie total tidal volume. These volumes of actual tidal prisms are designated herein as "tidal prism volumes." The determination of actual tidal prism volumes is made possible by the continuous records of tidal stage obtained from the several automatic tide gage stations established in the basin, combined with the tabulations of tidal volume compiled in tlie manner previously described. Typical tidal prisms for the delta and for Suisun Bay are shown on Plates XL to XLV, inclusive. These are representative of a large number of actual tidal prisms compiled and computed for these basins covering considerable variations of tidal range. As an example, Plate XL, "Tidal Prism Volumes in Sacramento River Channels," shows the tidal prisms or changes in tidal volume during a tidal cycle on August 27 and 28, 1929. The instantaneous position or profile of the water PLATE XL 3 2 1 3 *^^ 2 ,£ • 3 00 CO *3 o •1- 3-D Jii > f=u, O (- □C o •s u E / Slack water after low \ 1 1 i|h tide at Collinsville, 10:21 AM. -Aug. 27,1929 ..--'-A' — — _- -_: ;^ ' 1 1 __ ! = = X- — = — ;^=t : ^ [Q^_^JiO — " 5^ i= = = p — — ^^~^ —J '-^^ ^^ r^T!ooMv -Au5,2X«" — — ■ — ■" HMFp-m. 5s — - ■:^S^ '<^^^ "h" gh lovN tide ' — . 3 O +- -o3 4} L. U •I- 2 L. ♦- (U w c o ■p" > ___-=. — = :^= = ■--ftp */"= ,-- SlacK water ; J 1 after high h' Jh tide at C ollinsville.9-.27 P.M.-Au^.27.l929__ _ [."3:-"^-- ;_ i_cr " -3:00PM.4j— -^= ■q rrr— — J ^ — -'' ,— — ^ ,^V.OOV^■ ^-"-'' ~.^'^'^^^ fiw^..- ^ —^^ ^^_ ■^-^^ — _ ^^r= = — =^ 1^ "" „^— ' Z~-' »" --'" — - — ^,^..00^^* >< — — -•-"' ?w1^ -^Im^^ t^^^"^^' -- — — — SI JT^S?^ ■^Ti^ ;^ =.^^ ■— ^ — — — ^ ^'~ 1 24 28 32 36 40 44 48 DisTance in miles from lower end of Cinain Island 0) 1- 0) 0) in c o TIDAL PRISM VOLUME Computed from slack water to slack water Change in volume in tidal basin Tidal period Low hi^h to high low High low to high high High high to low low Low low to low high Total Increase Decrease 13,700 38,400 45,700 24,000 "62,400 59,400 NOTE Slack water lines as shown indicate the position of the water surface throughout the tidal basin at the time of occurrence of slack water at Collinsville.Time of slack water assumed at I'A hours after time of occur- rence of tidal phases at Collinsville. TIDAL PRISM VOLUMES SACRAMENTO RIVER CHANNELS 80995 — p. 172 PLATE XLl Distance in miles from lower end of Chain Island TIDAL PRISM VOLUME Computed from slack water to slack water Change in volume in tidal basin ■r J , J Acre -feet ^"'»' P^'"'°<' Increase Decrease Low high 10 high low 11,600 High low 10 high high 28.700 High high to low low 4A,500 Low low to low high 30.600 Total "59.300 ^56,200 NOTE Slack water lines as shown indicate the position of the water surface throughout the tidal basin at the time of occurrence of slack water at CoUinsvitle.Tlme of slack water assumed at I'A hours afler time of occur- rence of tidal phases at Oollinsville. TIDAL PRISM VOLUMES SACRAMENTO RIVER CHANNELS SOOilS— p. 172 PLATE XLII 20 24 28 32 36 40 44 48 Distance in miles from lower end of Chain Island (D 0) in c o '■(- > 03 TIDAL PRISM VOLUME Computed from slack water to slack water Change in volume in tidal basin E D Low high To high bw (0 High low to high high High high to low low c/) Low low TO low high u> If) Total Acre -feet Increase Decrease 19900 62.500 81, 30: 14,700 107,300 101,200' NOTE Slack water lines as shown md'care the position of the water surface throughout the tidal basin at the time of occurrence of s'acK water at Antioch.Time ot slack water assumed at \'/u hours after lime of occur- rence of tidal phases at Antioch. TIDAL PRISM VOLUMES SAN JOAQUIN RIVER CHANNELS -p. 172 PLATE XLIII 1/1 d T3 -1-f i 1 s FLOOD TIDE frljgh low to high high) 3 5 S m a: J a 1 1 EBB TIDE (High high 10 low low) " i a: __ i ,,^ J 1 § , Slack water afier fitgh high ide al Am, Wnt 3l!A_M.May M. 930 a: — i -ilOOflH_ ^^^-^ ^Ojitt^.^- Xi ~=^ ~"~H^^" :^e- ~-^ -= ~-^., :^ -^■" -- "•" • ." 1 -— .— — _ ~~~ 303 ?oo =^= ■=T^ rr: 2=- ■ — ' ^--■^^ -j^ ^ ■^^^ ^ -'^-^'' ^ ^ 6 00 AM- - SOOAll" ' ^-^ ^--- — r^ ^^^^ i^ 5^=5 S i^ ^^:lC 'y^^- ^^ --' '■ -— - — JJ^OO f= IIXIAU-. ..Si^ ;=^^ P>^^ - ^"^ ^ •^— --. ::::z !n ~" ^^-^ "i--^ ' _- - 1,00 >» a 00 f^'* _^^ ^--^"^ - ■V- ""^■.i^lSi^ M«o^ ^^^""^ >^=^^ =^^^ •- =— :e^ Sfack waier aficr .Igh low 11 r '■ ■ 1 t t at Arinj Point 9:18 PM..May 13.1930 - -^ . 500 "■i*- -^^ '-.^^^ _w«^ - --- — ' _. ■ =^^=^ -'^ ■"-' ^ 104 1 108 1 2 1 6 -^ ^^ 1 108 1 112 1 6 120 124 m ACRAMtNTO RIVER CHANNELS E to to 1 1 -E 1 SACRAMENTO RIVER CHANNELS 1 -0 (n U5 s 1 1 % c i > 9 8 7 6 5 3 2 C -2 -*< M, TIDAL PRISM VOLUME Computed from slack water to slack water Change in volume in tidal basin Tld8) period Aer,.fe« High low to high high 156.700 High high W low low 276,700 Low low to low high 192.000 Low high to high low 51.400 Total 3Wod aitaioo NOTE SlacK wBter lines as shown indicate the posit ibn of lime of occurrence of alach water b1 Benicia ■ Time of sl»ck wotcr asiume'S st iVi hours after lime of oeeurrefw of tidal phases M Benicla. Thi5 and the followini! plale show tidal prism vDlume! for one ccmplere lida! c/cle f^vl3-l''.l930. £ 3 s « ■s b 3 1 S ' - ( c o 1 1 i f ^ 1 , ^ 1 1 1 f 1 1 ^ ^- ^ i g i 4 1 ■' 1 .° _ v^ ^ 1 ,i £ 1 r 3 3 1 u I 2 5 \ .^ 5^. 1 s 1 ~t V^ ;^ 1 ' 1 1 $ 1 ^■^^ a ^ 1^^ ^^- ^ f" Slack warer after hig high tide at Arm Point 3:i2fr^-^ ;J^ UOQ,„ -- ^ ^ ■'J,'''OM;dn,gh -- — i r-'^^r ^ ^ ^ -' ^ — — -\ — - •><<* <^ r^ — — - 10 DOPM - -9.00 PM ^ P- -Si.c.-i .f«r ki. lov- ae ai Army Fb.m 9(8 pill ytAf 13, 19; FLOOD TIDE (H^h low to high high] ^^ y ^ ^^ - - — — — '"' ■^ y^ kf-*' 1 EBB TIDE (hi^ high to low low) y^^y'^':.^ ,.-■ ^ / / -" _-- s yy'-\ y y -' 7 iP ^ .S «»" 'SteTtow TIDAL PRISM VOLUMES IM SUISUN BAY AND DELTA CHANNELS - A -4^ iJTf" J'^ 3b 10 ftt as M3 t: S6 SO W 68 72 76 BO 84 88 92 96 lOO KW"" Distance in miles from the Golden Gate 32 3e 40 tt4 4B 503 52 J.6 60 64 6B 72 7G 80 84 88 92 9G '00 Distance in miles from the Golden Gate 104 lOB soy&s— p. I FUATE XLV - 1 1 1 ■-^1 : j ':U2IUE i^ 1 f — ■ ' " - t I OOt r' 1- IL 3 c & (V t: o U> (A (0 9 ». ^ en .a OJ- 8A 'CW ♦* lOS 0* iae iG -e«808 VARIATION AND CONTROL OF SALINITY 173 surface in the basin for each hour during the tidal cycle is plotted from the automatic tide gage records. The uppermost diagram on Plate XL covers the period of ebb from low-high to high-low tide ; the second from the top covers the flood period from high-low to high-higli tide; the third diagram covers the ebb period from high-high to low-low, and the bottom diagram covers the flood period from low-low to low-high tide. The heavy lines at the bottom and top of each of these diagrams show the profile or position of the water surface at time of slack water follow- ing the several tidal phases. Hence, the area between these two heavy lines graphically represents in cross-section the magnitude of the actual change in volume in the tidal basin during the particular periods of ebb and flood. The computation of the actual change in volume between tidal phases is based on the actual water levels shown in these diagrams, com- bined with the tidal volumes shown on Plates XXXVIII and XXXIX. These computations of volume were made for each two-mile section. Using the vertical range between the upper and lower water level at time of slack water and the variation of volume per foot of depth as shown in the tabulations on Plates XXXVIII and XXXIX, the total volumes for each tw^o-mile section are readily computed. The volume above and below elevation -\-l U.S.G.S. Datum was computed separately in order to take care of the variation in volume per foot of depth as between upper and lower zones. It was not considered necessary to use any smaller subdivisions of vertical depth than those two. The total tidal prism volume was then obtained by summing up the volumes com- puted for each two-mile increment. It will be noted on Plate XL in the ease of both the period of ebb from low-high to high-low and of flood from low-low to low-high tides that the change in volume in the extreme upper part of the basin w^as opposite to that in the lower part. In other words the water levels in the upper part of the basin were rising, while those in the lower part of the basin were falling and vice versa. In computing the total change in volume for such cases, the volume changes of opposite sign were added algebraically. The tidal prism volumes computed in the above manner, are shown tabulated on each plate. The total change in volume during flood and during ebb tides very nearly balance each other. This is characteristic of all tidal movements in the tidal basin, especially during periods of low stream flow. The difference between the total change in volume for the two flood tides and for the tw^o ebb tides is repre- sented by the difference in water level in the basin at the begin- ning and end of the tidal cycle. If the water level at the beginning and end of the tidal cycle happens to be the same, which is frequently the case, the volume changes during ebb and flood wdll equalize each other. The effect of greatly increased stream flow upon the shape of the tidal prisms is shown on Plate XLI, covering the tidal cj^cle period of December 18 and 19, 1929, when the flow of the Sacramento River past Sacramento was about 100,000 second-feet. As would be expected, the profile of the water surface in the basin is materially changed from that of the low stream flow period, the water levels in the upper part of the basin being generally at much higher elevations. The shortening-up of the tidal basin with the limits of tidal action pushed downstream is evident also. All of the tidal prisms extend only 174 DIVISION OF WATER RESOURCES a sliort distance above AValiiut Grove whereas, durinnf the low flow period, tlicy extend Jiboiit twelve miles above Sacramento. Tidal prism vohunes have been comjnited in the above manner for the delta and for Suisun Bay coverin<>: typical variations of tidal range in the ba.sins and for several ditferent tidal cycles during the low water season within the period of advance and retreat of salinity. The results of these computations are .shoAvn in Table 24. This table shows the com- puted increase and decrease and net change in volume in the tidal basin and the corresponding tidal range from slack water to slack water at the lower end of the basin ("Home Section") for numerous typical tidal prisms covering the delta alone and all or portions of Suisun Bay in combination with the delta. The change in volume in tlie tidal basin of the delta and Suisun Bay 'between successive tidal ])hases is related to the tidal range at the "Home Section" between these two jihases. This is grai)liically shown on Plate XLVI, "Relation of Tidal Prism Volumes to Tidal Range (Antioch and Collinsville Home sections)" and Plate XLVII, "Relation of Tidal Prism Volumes to Tidal Range (Suisun Bay Home sections)." The points plotted on these diagrams are based upon the computed tidal prism volumes and the coincident tidil range at the section at the lower end at the tidal basin, designated the "home section." The relation api^ears to be approximately a straight line variation. The actual plotted points depart somewhat f i-om the average lines, but the variation is not ot' great magnitude and it is believed that the relation indicated is as accurate as the data and computations warrant. The relation established is of great value inasmuch as it saves a tremendous amount of detailed computations Avhich would be required to obtain the tidal prism volumes for each tidal cycle during the season. AVith the use of these established gra])hical relations, the tidal ))rism volumes or net changes in tidal volume in the tidal basin for any tidal movement can be obtained immediately from the diagrams with the known range of the tide available from the tide gage records at the home section. Tidal Flow — Tidal flow is detined as the amount of water entering or leaving a tidal basin between any two successive tidal phases. The actual tidal prism volume or the change in volume in a tidal basin between any tAvo successive tidal phases is a measure of the tidal floAV passing into or out of a tidal basin. HoAvever. it is not an exact measure of tidal flow. The exact measure of tidal flow must be based not only upon the change in volume in the tidal basin but also upon the additions and extractions from the tidal basin dui'ing any particular ]ieriod of tidal floAV. These additions and extractions consist of stream infloAv and AAater consumj^tion. respectively. Tlie actual change in volume in the tidal basin is the combined result of the tidal flow entering or leaving the tidal basin and the Avater entering and leaving the basin by stream floAV and consumption respectively. Considering any period of ebb or flood betAveen two successi\'e phases of the tide, the magnitude of tidal floAV into or out of a tidal basin is expressed by the f olloAving formulae : t = v — s + e (for flood tides) t = V -|- s — e (for ebb tides) Avhere, t = the tidal floAV entering or leaving the tidal ba.sin V = the change in volume in the tidal basin s = the stream floAV into the tidal basin e = the extractions of water from the tidal basin. VARIATION AND CONTROL OF SALINITY 175 PLATE XLVI ANTIOCH HOME SECTION -SAN JOAQUIN RIVER •00 c (0 L. "(0 -a ^ _^ o ^^ ^ ^ ^^ ;^ ^ .'' o ^ 10 20 30 40 50 60 70 80 90 100 110 Tidal prism volume in thousands of acre-feet g COLLINSVILLE HOME SECTION -SACRAMENTO RIVER p a o .'' A o ^ o O a D •> Q o >^ o i 'S 5 10 15 20 25 30 35 40 45 50 55 Tidal prism volume in thousands of acre-feet RELATION OF TIDAL PRISM VOLUMES TO TIDAL RANGE LEGEND o stream flow into delta less than 6,000* sec.-ft. o Stream flow Into delta more than 100,000 sec. -ft. (from Sacramento River). 17G DIVISION OF WATER RESOURCES PLATE XLVII \ SUISUN BAY HOME SECTIONS . - ° 9 o ^o3 — .5 o S ^ - fc 3 «^ ..5 o " S. I CO *-l « CO tOQO 0000% ^H C^ 0 U? kO OOOOOOOOOOiOO-^OOCDOOOOO '<*«O00t0C^C^It-.':0.— iM fCCOCOC^C^fCOiOO^* O O =o -H lO t-» t>- ?o c> c^^ O O lO t^ Oi t^ (M lO .-« (M l^ to CO CO -^ CO C^l c^ C^l M t^ M W5 »OC^COC<^HOi'*«C^^05COOO«0'-«t-*eO»C^-HCO »oasc^ococcioccoo t--*<-j e^ c*5 O t>- 00 oo OS t>- lO <0 -^ -^ CO -^1-tMC^CO a Is? OOOOOOOOOOOOOOOOOOOOOOOOOOOiCcosOOOW'^OOOOO OOOOO'— 'Oi'^J'QOCO'OOSOr^'— 't^t^^'^t^'^OI^CI^'^l^— 'OSCO C'*C^C3O00'— !©00^0 r-t^^^.— f^co'-9'-— 'COOOiOCDO^H'OiO^CVlOeoOOCSiOOOCO'— oseoOio OOr^C^':DOOCOOCOOScO"^C^OSOC>100cOMiCt-CDI--OOC^10ir'- •-»C^COCO^C4t>-C^ COCOCDOOCNl»-HCOCOCOMC>^C^C^^riOOOOOOOO'-'OSCSOSt^COiO •-•(NC'ICOCO^ OOOOOOOOOOOOOOOOOOOOOOOOOOOtM-^ iO^J*C0'-HOCD(MTt •-ico:o^r^ooooast>-iccDiO"^co ^(:00'1'-«C-)'- . . . .. _*__•_ o o o S^-g 3 D 3 u u oJ2 § §*533 3 = 3 o o o o o o^ 5 ^ 3'B3'B3'5 -; -i »-HCSlC0»-«MC0'*i0e0t*00 0S»--c0C<»^• iM '-' 1— • CO ^C TJ< -?0T}«»-t :0'^'^CCt-t^'-'OCOiOcDOOI>-000 (MCO OOOOOOOOO03^a::: hi; ^ <; <; <; <; < < J eS ^J3 OS GO fl B a J3 s > .2 o< Cs; 182 DIVISION OF WATER RESOURCES Tidal Variations of Salinity — The effect of tidal action on the variation of salinity at points in the bay and delta channels is best indicated by the results of the special tidal cycle salinity surveys. The data com- piled from these surveys are summarized in Table 25. The variation of salinitj' during a tidal cycle resulting from tidal action is more clearly shown, however, in graphical form. Plates XLVIII to LIX, inclusive, "Tidal Variation of Salinity" graphically present the results of typical surveys of this type made at fourteen stations in the bay and delta channels during 1929. In general, the surveys shown in graphical form have been selected to illustrate the variations under different salinity and tidal conditions. Two surveys each are shown for Point Orient, Bulls Head Point, Bay Point, Collinsville, Antioch, Antioeh Bridge, Rio Vista ; three for Crockett; and one each for Avon, Nichols, Central Landing, Curtis Landing, Sacramento and Mossdale Bridge. Immediately below the salinity record on each diagram is shown the record of tidal stage. Separate lines are shown for the variation of salinity at each depth zone sampled. Thus, the graphs show the variation of salinity not only at various depths throughout the period of the tidal cycle, but also show the relative magnitude of salinity at the various depths from surface to bottom at any particular time. "While in some cases the survey data appear to indicate a con- siderable complication in the variation of the salinity at different depths, there is exhibited, nevertheless, for most of the surveys a sub- stantially parallel variation at all depths from surface to bottom. In general, the data show that salinity increases and decreases prac- tically in parallel Avith the rise and fall of the tide, thus demonstrat- ing the direct effect of tidal action on salinity. There is usually a lag between the actual time that the high and low phases of the tide occur and the time of occurrence of maximum and minimum salinities corresponding thereto. The maximum and minimum salinities occur generally from one to two hours after the time of occurrence of high and low tides respectively, with an average lag of about one and one-half hours. As will be shown more clearly with the tidal velocity surveys, the actual time of occurrence of maximum and mini- mum salinities corresponds with the time of slack water following high and low tides respectively. The data compiled in Table 25 are of great interest. For each tidal cycle survey are shown the minimum, maximum and mean .salinity in the surface zone and in the vertical section and the relation of mean surface zone salinity (Ss) and mean salinity in the vertical section (Sv) to the maximum surface zone salinity (S). Both mean surface zone and mean vertical salinity are com]iiled as an average for a complete tidal cycle period. It appears from these data that the mean salinity in the sui'face zone (Ss) and the mean vertical salinity (Sv) for a tidal cj'cle period are usually about equal in magnitude. For all the surveys, the mean vertical salinity in per cent of mean surface zone salinity varies from about 92 to 115 per cent. The mean vertical salinity is usually only 3 to 5 per cent irreater than the mean surface zone salinity. Hence, the relations of both mean vertical and mean surface zone to maximum surface zone salinity are about the same. The relative magnitude of mean surface zone and maximum VARIATION AND CONTROL OF SALINITY 183 PLATE XLVIII 1800 SURVEY NO I QJ Q. ex 24 68 10 12 2468 10 12 246 Oct.lOJ929 -H^- Oct. 11,1929 c o 1600 O 1500 CO c lAOO 1300 1200 1100 ^Mean salinity in surface zone <\alinit\/ Depth of 50 feet to 2 4.68101224681012246 Oct. 10. 1929 H' Oct.llJ929 <1> ^, sr^ \ K c / " f^ ^ > © -\, :2 — '~y ^__ J^ __^. -• - o k" Mean tide 'S.eOfeef^ X 5> f7 Tide sta^e- >\ y g o in N€ ap ti de o ■z. c UJ 2 4 8 10 12 8 10 12 Oct.lOJ929 Oct. 1 1,1929 TIDAL VARIATION OF SALINITY CROCKETT LEGEND -SALINITY *T DEPTH Of I FOOT (sur«t ZOMt ) II •• .. .. 10 KET .. .. .. I.JO .. 30 " to .• ■ SALINITr AT OtPTH OF SO FttT to 70 to 2 FtfT FROII BOTTOM 186 DIVISION OF WATER RESOURCES PLATE LI SOO SURVEY NO 2 Mean salinity in .surface zone — a> o o CJ o o 6 8 10 June 1.1929 6 8 10 12 2 June 2.1929 SURVEY NQ8 4 6 8 10 12 Aug. 2, 1929 -H- 6 8 10 12 2 Aug, 3. 1929 TIDAL VARIATION OF SALINITY BULLS HEAD POINT LCSCND -SALINITY »i otPTM or I FOOT (su»r»ct aw) 10 FEET •• • 20 " 2 FECT FROM 60TT0U VARIATION AND CONTROL OP SALINITY 187 PLATE LIT 1200 ■*T^-V- AVON — SURVEY NQ| QJ Q. c 900 2 4 5 8 10 12 2 A 6 8 10 12 Z 4 Nov. 4,1929 >h Nov. 5, 1929 NICHOLLS — SURVEY NQI 600 o ^ 700 u 600 500 AOO 300 >> 2468 10 12 2468 10 12 246 Nov 19, 1929 > l * Nov 20, 1929 TIDAL VARIATION OF SALINITY AT AVON AND NICHOLLS -5»i.l'Jirv i.r OCfTM OF 1 FOOT (SlSFftCE 20M) 10 FEET to •» 7 'I^.T FBOV BOTTOM-" 188 DIVISION OF WATER RESOURCES PLATE LIII 1000 SURVEY NS 1 & t- o O tlfl CD c^ O c cf c o ■?f' CO c iZ o Tide stage Spring tide 10 12 2 A 6 6 10 12 2 4 6 8 10 Nov. I, 1929 — H— Nov. 2. 1929 SURVEY NS 2 12 i->IOOO 2 A 6 8 10 Nov 26, 1929 4 6 10 12 Nov. 57, 1929 TIDAL VARIATION OF SALINITY AT BAY POINT — ^^^^•^^^^■^ LC6CN0 ° SAUNITY AT DEPTH Of 1 FOOT (su«f»Ct ZONl) a O FttT . .. .. .. .. 20 '■ O • •• ..2 reCT FROM BOTTOM VARIATION AND CONTROL OF SALINITY 189 PLATE LIV 120 100 60 "fo 60 in SURVEY NQ 5 <0 o. o o CD" O (U a. 0) c o u 20 - Between spring and neap tides . ^Mean salinity in ■*" ■ surface zone - E D ■•— x> CO d =5 0) "OO (D ••— ^ '.^ 20 at ^'A ! Y (^ 'Salinity / K^ \ ;«A f \--. y . Mea n vert iral f --\ L-^ ^" / salinity i _J^ ^w/i Mean salinity ~f c o \ ^ \\ in 5u ' nace zone A f ■z. 1 ^ ^. J I is Uf — H— - O c CO K — ^ > X ^ y^'"^ _.-^ s^ Mean tide- 3.20 feet,^ ^ 0) **- O /T ' ^s / / ■^Tide sTa.^e X s^ / Neap tide UJ 4— 0) -o 10 12 2 A 6 8 Nov. 10, 1929 10 12 4 6 8 10 12 Nov. II, 1929 TIDAL VARIATION OF SALINITY AT ANTIOCH BRIDGE LEGEND ■ SALINITY AT DEPTH OF I TOOT (suRf ACE 20Nt) FCtT ,. .. !• 20 •• • ' 30 " ■• " J FEET FROM BOTTOM 192 DIVISION OF WATER RESOURCES PLATE LVII SURVEY N5 2 4- o Q. o o o o' o J- Q. c _o o Q. c to ^ i Mean Vertical .Salinity 10 12 2 4 6 8 July 5, 1929 10 12 2 4 6 8 10 12 July 6J929 E -»- •o to I ^ 0) 0) 3«f- c ^■^ •1:2 ■2 90 SURVEY NQA n 70 m » 'Salinity i / Y 50 /// V •'/ c 8 30 I- Mean vert / salinity cal 2 -.-. 1 ~ r r .--- y) 5 ■ -L- rs' - -* .-.-_-. .---.- r.-.-.- .-.-.-- 10 M s-^^J.gr^^'s^ pi^ Ns^ nJ U^ .^^ i^-ftfJ *^ h / ^ Mean salin in surface : ty .one / \ V^ Mean tide =1.33 feet >^ -^ ^- c llJ -y4 r — -\ / — — 7 /!_ \" ii^ ■\ \, / X ^ Tide staj^e V / f CD Tropic : tide \ ^ CO T3 to O to ID A 2 FEET FROU BOTTOM 13—80995 194 DIVISION OF WATER RESOURCES PLATE LIX SACRAMENTO I ST. BRIDGE - SURVEY NQ3 2 4 6 8 10 Aug.6,1929 0) c MOSSDALE- SURVEY NQ3 spring tide 0) (0 2^ 1 .:5 A 6 8 10 12 Aug. 5, 1929 -*k 6 8 10 12 2 Aug. 6. 1929 -2 TIDAL VARIATION OF SAUNITY AT SACRAMENTO I ST BRIDGE AND MOSSDALE LEGEND O SAUNITV AT DtPTM OF I FOOT (SURFACE ZONE) A ., . „ ,, ,. 10 fi^x a '• ■' 2 FCCT FROM BOTTOM PLATE LX Ti! iS after occurrence of ^a^e height UO 680 720 760 800 840 880 920 960 ,400 1,500 1,600 1.700 rs after occurrence of gage height 1.800 VARIATION OF SALINITY WITH TIDAL STAGE 194 DIVISION OF WATER RESOURCES PLATE LIX SACRAMENTO I ST. BRIDGE - SURVEY NQ3 /t I \ WJ /M- ,. .. T^>Salinity I Mean salinity in J / surface zone \jt L e +- CD •o i/i I 12 2 A 6 8 Aug. 5, 1929 2 « 6 8 10 Aug 6, 1929 a> Q. a> c MOSSDALE- SURVEY NQ3 4 6 8 10 Aug. 5. 1929 12 6 8 10 12 2 Aug. 5. 1929 TIDAL VARIATION OF SAUNITY AT SACRAMENTO I ST BRIDGE AND MOSSDALE LEGEND O SAUNITV AT OtPTH Of I FOOT (SURFACE ZONE) » „ . ., ,, ,, ,0 rtcT D •• ■• 2 Ftrr FROM BOTTOM PLATE LX Surface zone salinity in parts of chlorine per 100,000 parts of water V/i hours after occurrence of gage height 80 1 20 160 200 240 2B0 320 36 ^0 440 480 520 560 b O O 640 6 8 72 760 ^BOO 840 880 920 960 COLLINSVILLE N?^ 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1.700 Surface zone salinity in parts of chlorine per 100,000 parts of water \V^ hours after occurrence of gage height 1.800 note; Compiled from tidal cycle salinity surveys during 1929 VARIATION OF SALINITY WITH TIDAL STAGE S099D — 1). 194 : ff^»' ,^*i\.'?, ' '! \ !.«<;» '^ \ \- ■ ^ - ^0 ^w* • b (i I -4- 1 CD I ; i WOBST o: ■■MBVWI VARIATION AND CONTROL OF SALINITY 195 surface zone salinity exhibits marked variations both for different mean salinities and for equal mean salinities. Thus, for tidal cycle surveys No. 6 and 7 at Collinsville with a maximum salinity of 284 to 310 parts of chlorine per 100,000 parts of water, the mean salinity in per cent of maximum salinity shows a variation of from about 47 to 74 per cent. Again, for surveys No. 20 and 14 with a maximum salinity of about 580 parts per 100,000 parts of water, the mean salinity in per cent of maximum salinity Avas 69 and 80 per cent. Many other similar examples could be pointed out in the tabulation for any station. It is evident, therefore, that there is some modifying influence or factor, "vih^ch is responsible for the variation in relative magnitude. The studies show that this modifying factor is the variable character of the tia > and in particular the variable range and diurnal inequalities of tb" tide. It is therefore impossible to obtain any simple relation oen the magnitude of mean and maximum salinity during a tidal '■ without taking into account the vai'iable character of the tide. nation of Salinity with Tidal Stage — It has been pointed out pre- \iourV that salinity varies during a tidal cycle in parallel with the rise and fall of the tide. That this is true is more clearly shown on Plate ''iX, "Variation of Salinity with Tidal Stage." The graphs on Plate uX have been plotted from the data of the tidal cycle salinity surveys. Taking into account the lag averaging one and one-half hours between the time of occurrence of high and low tides and the maximum and mininum salinities corresponding thereto, the graphs on Plate LX nav^ been prepared by plotting the gage height or tidal stage above ' DWo.jt low water against the salinity in the surface zone one and one- half hours after the particular gage height. Smooth curves have been f^raTNu connecting the points thus plotted. While in detail they take 1 a I itlier fantastic form, there is exhibited, nevertheless, a funda- lent^l relation showing that salinit}' directly increases and decreases respectively with the rise and fall of the tide during a particular tidal cle. Ti"3 mean relation of tidal stage to salinity is shoAvn by the dashed lirioc- oj each diagram. For the most part the actual departures from . i: lean lines at different times during the tidal cycle are not of '' magnitude. The diagrams show that the rate of variation of 'r / with tidal stage gradually increases as the salinity increases, ng a maximum variation with salinities of about 800 to 1100 r+ of chlorine per 100,000 parts of water and then gradually decreas- :• higher salinities. The variation shown appears to be an entirely ;■ ':>1 one. It is evident that, for entirely fresh-water or entirely salt- t r conditions, there should be no variation of salinity with the rise id 1 of the tide. It appears reasonable that the maximum variation oaid )e found for water with about 50 per cent saline content. This mov clearly shoA\Ti on Plate LXI, "Rate of Variation of Salinity ith ± :dal Range in Relation to Mean Salinity." The graph on this 'ate has been plotted using as ordinates the mean rate change of sur- face zone salinity per foot of tidal range during a tidal cycle and the mean surface zone salinity for the tidal cycle as abscissae. Based upon the relation established between variation of salinity md tidal stage during a tidal cycle for various mean degrees of salinity, there is presented on Plate LXII, "Relation of Salinity to Tidal 196 DIVISION OF WATER RESOURCES PLATE LXI m t: o CD O o' O t_ .- o in XI 03 Q- 100 90 80 70 60 ro 50 T3 ,8 40 2^ c o o 13 ■oo c: JO. o 30 20 10 Mean tidal cycle surface zone salinity in 100 parts of chlorine per 100.000 parts of water 4 6 8 10 12 14 16 18 20 o yr \ r ^ o / o ^ o X \ go \ o / \ o ~Y ~~ \ / o \ o / \ / V / O * i o \ / \ o F t I o \ — rcr T o| \ NOTE The mean surface zone salinities for the tidal cycles were plotted as abscissas. The rate change per foot of tidal range was compuTed by dividing the difference in surface zone salinit^^ in parts of chlorine per 100.000 pans of water after high htgh and low low tides by the tidal range in feet between high high and low tow tides, and these values were plotted as ordinates. RATE or VARIATION OF SALINITY WITH TIDAL RANGE IN RELATION TO MEAN SALINITY PLATE L.XII to a. c *i_ _o JZ u I- Q. 140 160 NOTE The percentage on each line of the graph represents the height of the tide at any time in percent of the height of mean tide for the tidal cycle, both above lowest iowwater. Compiled from tidal c_yc!e salinity surve_ys. The points on the graph are plotted for typical surveys. (0 a> c o M Oi O (0 M- l- 1900 RELATION OF SALINITY TO TIDAL STAGE 196 DIVISION OF WATER RESOURCES PLATE LXI -♦-- Q. o O) o «1 0) ■OO c <0 jC o (U 40 30 20 10 Ojr » r \ o o X \ go \ oy \ ^ o "P \ / o \ M o " °\ o / \ / V i ** \ / O \ O f I O NOTE The mean surface zone salinities for the tidal cycles were plotted as abscissas. The rate change per foot of tidal range was computed by dividing the difference in surface zone salinity in pans of chlorine per 100.000 parts of water after hi^h high and low low tides by the tidal range in feet between high high and low low tides, and these values were plotted as ordinates. RATE OF VARIATION OF SALINITY WITH TIDAL RANGE IN RELATION TO MEAN SALINITY PLATE LXII l»OU c "^1800 0) g^ieoo ^1500 15 !?1400 2 ■u- .'<^ o CO o- -z — 1 O' z 9 J TD — ^ r5 i 9/// SI z "o c o t £ J^ t y\/ O oo 5o 1 O' Z C D o> z "o SI u z / ^ {/, o o o 1 15- C *p // >'°o\o \ CD c o 5 1 en •E "= c *- 3 ^ y^w fe c •— -inn S X 'V Vj^x^^ y C O o c (Oft) J ^ ^^ AM- SI Z w Oi z 01 ^/ ^ ^ < /Y r o i yI Surface zo o o < ^ p ^ j^. c o 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 Mean surface zone salinity in parts of chlorine per 100,000 parts of water for tidal c_ycle (Sjt) 100 120 140 160 The percentage on each line of the graph represents the height of The tide at any Time in percent of The height of mean tide for the tidal cycle, both above lowest low water. Compiled from tidal cycle salinity surveys. The points on the graph are plotted for typical surveys. RELATION OF SALINITY TIDAL STAGE 80995— p. 196 ■ DOS J -+-■ G VARIATION AND CONTROL OF SALINITY 197 Stage," a comprehensive graph showing in detail the relation of salin- ity to tidal stage for all variations of tidal conditions and degrees of salinity covered by the surveys in 1929. The basis of compilation of this diagram is somewhat complex. From the mean curves of variation of salinity with tidal stage, typified by those shown on Plate LX, cor- responding values of salinity and gage height were taken at convenient intervals of salinity and tidal stage. The actual gage height was then expressed as a percentage of the height of mean tide above lowest low water at the particular station. Thus, mean tide is expressed as 100 per cent. The mean salinity for the tidal cycle also was determined for each survey. Points were plotted on the graph, using mean sur- face zone salinities for each tidal cycle as abscissae, and the different values of salinity for various gage heights, as taken from the mean curves, as ordinates. Each of these plotted points was then marked with a percentage computed as the gage height (corresponding to the particular value of salinity) in per cent of the mean height of the tide, both above lowest low water. Through the points thus plotted, smooth curves were drawn representing the variations of salinity for different tidal stages expressed as a per cent from zero to 180 per cent and at intervals of 20 per cent. The derivation of the diagram shown on Plate LXII of the rela- tion of salinity to tidal stage represents one of the important contri- butions of the salinity investigation. It has been of invaluable use in carrying out the analyses of the relation of salinity to stream flow and tidal action. All of the records of salinity which furnish the basic data on variation of salinity during invasion and retreat for the last decade have been from samples usually taken after high tide. The salinity records of the regular observation stations therefore represent nearly maximum degrees of salinity at the various stations on the dates when samples were taken. The relations of salinity to stream flow and tidal action, however, have to do with the variation and advance and retreat of mean daily, or tidal cycle, salinity. Therefore, inasmuch as it is evi- dent from the data heretofore presented that mean salinity does not bear a constant relation to maximum salinity during a tidal cycle for all degrees of salinity and for variable tidal conditions, it has been deemed necessary to use mean salinity for a tidal cycle instead of the maximum salinities of the observer's samples. In all of the relations analyzed in this study as between stream Aoav and i=alinity and as between tidal action and salinity, mean surface zone salinity for the tidal cycle, or, what has been termed for convenience mean surface zone salinity, has been used throughout. The use of the diagram is explained as follows : Having a value of the surface zone salinity determined from an actual sample taken at any particular time, the diagram is entered with this value on the ordinate scale, and a horizontal line drawn to intersect the percentage line corresponding to the height of the tide, one and one-half hours before the time the sample was taken, in per cent of the mean height of tide, both measured above lowest low water. The mean surface zone salinity is then taken off the abscissa scale of the diagram by drawing a vertical line directly from this point of intersection to the abscissa scale. The salinity at any other stage of the tide is also readily obtained at points on the ordinate scale directly opposite horizontally from the 198 DIVISION OP WATER RESOURCES l^oints of intersection of the vertical line previously described with the various curves of percentajre of tidal stage. For example, if the observed salinity is 500 parts taken about one and one-half hours after hip:h-hi! ' &i ., e (s) .. .. ■• iO ® NOTE Complied from IWb) eyeie Ullnily mrvFyj during 1929 VARIATION OF SALI^4ITY WITH DEPTH oos f-r X'^ M 001 ^ 71 i\ T^ t— t- 001 ' 1 ■ '' i oc. (Dl 0J« (0 Oi-tn ^ oe< oe o - ov- CD OG OT - , Ch •• -♦ 1 X) V y a> i 1 1 - 1 Q © ,_ J «ex .(|— 3««oi< VARIATION AND CONTROL OF SALINITY 199 salinities of about 1000 to 1300 parts of chlorine per 100,000 parts of water. For the low and high salinities as well, there appears to be less variation with depth. This is to be expected inasmuch as no variation should occur in the case of either entirely fresh or salt water. One of the most interesting surveys showing the variation with depth is that taken at Crockett (Index No. 20 on Plate LXIII) which was made on October 10 and 11, 1929. This survey covered a depth of channel of about 90 feet. The mean salinity varied from 1240 parts at the surface to about 1400 parts at the bottom of the channel or an increase of about 160 parts, or 13 per cent of the surface zone salinity, or about 0.15 per cent increase per foot of depth. Surveys at other points showed an increase of as much as 0.3 per cent per foot of depth for mean salinity. At the time of minimum salinity during this tidal cycle at Crockett, the magnitude of variation with depth appears to be about the same. However, at the time of maximum salinity, the increase appears considerably less, being not over 60 parts, or about 4 per cent of the salinity at the surface zone. Variations in the individual sur- veys from a gradual increase of salinity with depth are difficult to explain but are probably due in large part to the erratic character of the tidal currents which are known to exist in the various parts of the channels during the flood and ebb of the tide. The extent of lateral variation of salinity throughout a tj'pical channel section is indicated by the special river cross-section salinity surveys, described in Chapter I. These surveys were made chiefly at high-high tide but a few were made at low-low and low-high tide. The work was scheduled so that the samples would be taken as near as possible to the time of slack water following the particular high or low tidal phase for which the survey was made. However, each survey usually involved a time interval of tliree-quarters of an hour to an hour or more to take the large number of samples across the entire channel section. Hence, the actual samples taken over the entire section were not representative of a particular time. This was not important for the lower degrees of salinity in the surveys early in the season. However, for the surveys of higher salinity, the observed salinities were corrected by relations established from tidal cycle salinity surveys at Antioch.and Collinsville and values of salinity Avere computed for the time of slack water following the particular tidal nliase of the survey. These adjusted values of salinity have been used in the diagrams and tables presented hereafter. Table 26 summarizes the results of these special river cross-section salinity surveys. The data are more clearly illustrated graphically on Plate LXIV, "Lateral Variation of Salinity," which presents the results of typical surveys of this type both for the San Joaquin River cross-section at Antioch and the Sacramento River cross-.section immedi- ately north of Antioch, designated as near Collinsville. The location of these sections is shown on Plate III. The upper diagrams show the results of three typical surA^eys taken in the San Joaquin River at Antioch, two for high-high tide conditions on June 10 and July 31, 1929, and one for low-low tide conditions on August 4, 1929. The lower diagrams show the results of surveys for two high-high tides and one low-low tide in the Sacramento River cross-section above Collinsville. The heavy line represents the bottom of the river bed 200 DIVISION OF WATER RESOURCES > V) >- H HH ?: c NM C) ^ w 1/5 7 S! ve ^ "i NM S u CO < > 5 H CO o Cfl O > Pi (ft r u a o (/5 if- a I .^ Hi o "5 "c3 1^ Ji3.3i.S?.?f.»-a:5 5f-&.5f.Sf ic.5f.tf ■a ^- i:§M:l:f:li.-|:l|l-f*."l:t e " " " g2 OOO05O0SOO«^OOOC3OOO o -S c o. o 1: 3 c g B a a is C23333333333 = 22« •-■pie>9^>oo«iMc<5'««>n« 8^3 ■■S-S,J3 Sii ell VARIATION AND CONTROL OF SALINITY 201 w •a 0? 9 S " ca>2'3'S- 2"^ la 03 CO ^■. Sg°'a ,^ C M " « fi«S q; c3 <» C O';^ vr; H Cl. ca CI ^™ 1 G 2 CU u 1 «) ^o O ai CO C>^ < a: c u < a •a o =1 ^ jq ja ^ ^ -a J3 ^ -i3 ja ^ "2 -^ -« o-^-^ tj. jd -a ^ j3 j3 ja »a j3 ja J3 t^ja^Tja > O0101'^O»C»0C000'^00Od'^C0<©'— • C»00t~-00Ci0it-^t^000SI>-OC7>CTJ0iO5O Tpi-l»-li-H0005lOCO-«0"^ ■^iO"T}it^Oi»-H(M05'--H »0 CO OO CO t^ CO C^ CO o CO CN (M CO CO CO O '-« CO i>- CO T-H Cq (M CSJ ,-1 ^H CO 1-H ^H-sl-5l-,»-3t-^l-3l-^t-3l-t,h-3l-sl-5"<<;C»CQ rHC^eo^irieot*ooo30*- tn ^ M -« (o ja w M) m c* to .SPS'^ S3S -a t. SP t- ^ 1^ j^ i« O »- o ^ oja s.£3 sua a§i.ii.i ^<: a<.3< -<; S S 202 DIVISION OP WATER RESOURCES in profile on the line of the cross-section. The small circles represent the points where samples were taken and along side of each circle is shown the salinity in parts of chlorine per 100,000 parts of water, as determined from the analysis of the sample. There are also sliown the maximum salinity in the surface zone (S), the com- puted mean surface zone salinity (Ss), and the mean salinity in the entire channel cross-section. (Sa). Below each diagram is finally shown the relation between the maximum and mean salinities above described. The mean salinity in the surface zone and the mean salinity in the section is expressed in per cent of the maximum salinity in the surface zone and the mean salinity in the section is expressed in per cent of the mean salinity in the surface zone. The summarized data in Table 26 present similar percentage relations for all of the surveys made. In general, the data from these surveys indicate no large variations of salinit}^ either laterally or vertically in these channels. As shown in Table 26, the mean sectional salinity (Sa) averages 104 per cent of the mean surface zone salinity (Ss) for all surveys at both river cross- sections, and varies from a minimum of 95 to a maximum of 121 per cent. This is a measure of the magnitude of variation found. No abnormally high salinities w^ere found either along the bottom or sides of these channels. The variation of salinity in the surface zone across a river section is indicated by the relation of the mean to the maximum surface zone salinity. This relation for all surveys at both cross-sections shows a variation from a minimum of 60 to a maximum of 97 per cent with an average of 83 per cent. It would appear from this that, in any large channel such as those in which the surveys were made, there may be individual variations of salinity of considerable magnitude and that the single point observations of salinity at the regular observation stations may occasionally not be accurately representative of the average salinity conditions for the entire channel. This would happen per- haps only occasionally, but possibly explains the fact that some of the observed salinities at regular observation stations, as also some of the observed samples on tidal cycle surveys do not appear to follow in line with similar or related data. However, it is believed that the observed salinities in the surface zone as taken at the single point observation stations afford a close enough ajiproximation of the average salinity conditions in the entire cliannel for ascertaining the relative variation of salinity at various points during the period of advance and retreat. The results, hereafter presented, of the special tidal cycle salinity and velocity surveys afford further verification of this conclusion. Variation of Salinity with Tidal Velocity — The relation of tidal velocity 1o salinity is of significant importance because tidal velocity represents the basic element and direct evidence of tidal flow which is one of the chief factors affecting the variation and advance and retreat of salinity. Measurements of tidal velocity, made during 1929, have been described in Chapter I. Tidal velocity was measured by current meter at three stations in each of the river cross-sections on the San Joaquin River at Antioch and on the Sacramento River above Collinsville. The posi- tion of these current meter stations and the results of typical tidal velocity measurements are shown on Plate LXV, "Variation of Tidal PLATE LiXIV r ^ ANTIOCH Distance from left bank in feet —o — k) o- to o— Lo — < fcjl 382 384 385 397 I3S7 10 20 Hi^h High Tide Survey N° 13 July 31, 1929 12:25 A.M. to l:|0 A.M. ja 30 40 50 o», O' O O' ■'►S -133 IIB 120 123 6 13* o o' o Co qI o 1 125 117 ti6 113 116 130 128 1 SI 1 132 134 123 J22 rii i 12a : S,= I24 1 J ! 1* 1 131/ -o--o^-o — o!"-o — Oi-qf "VW 120 122 118 126 r33 j Sa1I35 1 1 , ' 1313, 4-0 — ol — a- -d — OH \ 142 136 125 126 126 I 1 1 1 ^"291 1 ' / \l52 J62 15*. 155 1«1 V ' J Low Low Tide Survey N2 15- Aug. 4, 1929 10:05 A.M. to 10:55 A.M. Sg in per cent of 5 = 90 Sa in per cent of 5 = 92 Sa in per cent of 83= 103 COLLIN SViLLE Distance from left bank in feet 800 1200 1600 2000 2400 2800 3200 Sg in per cent of S = 86 S* In per cent of S ' 93 Sa in per cent of $5=108 COLUNSVILLE Distance from left bank in feet SCO 1200 1600 2000 2400 2800 3200 s Low Low Tide Survey NO 14 Aug. 4, 1929 8 15 A.M. to 9:05 A.M. Sj in per cent of S = 69 Sa in per cent of S = 94- Sa in per cent of S^ = 106 NOTE figures in dia^gram show salinity In parts of chlorine per 100,000 parts of water High High Tide Survey N9 15 - Au^. 13, 1929 10:20 P.M. to l|:25 P.M. $5 in per cent of S = 93 Sa in per cent of S = 97 Sa in per cent of 5;= 104 LATERAL VARIATION OF SALINITY -13. 202 PLATE LXV Aug. 21.1929 ELEVATION OF WATER SURFACE AND MEAN VERTICAL SECTIONAL VELOCITY IN FEET PER SECOND Aug. 22.1929 *r Aug. 23.1929 VERTI CAL SECTI ONAL V ELOC ITY IN FEET PER SECOND Ebb ilde I Flood Tide Ebb fide Floo d tid e Ebb Tide Flood tide Eb I Water surfaceT i/ / ».; "tllB, c\-f,\t, Be.'So, ,^ .ffl i'l ^'i Oi,' =.-.\o, H,' M,'-. Hi'v ^'li .-ii /I, J, ,■ Lifsl /Pi PiV.Pt d«tl*(* NOTE: T>ie letters A, K. A, Bi ek.on the upper diagram Oes^t. r^pKJl (joinls ot rrean vertCal velocity for each seelion.corr'- """"""" .1 velocity curves designated by the fCf diagram Thu; Ihg pol^ .p^rt.^^l .jiilvLt^. ^r ->fe... putfd fiem 11 ne upper dijjran i-. (he'ruean vertical velKity of Jfec per seccod computed from ine veriical velocity curve marKe.: A{ in th« Igwer dutram The ligutei ihmn at ex^ plotted pciil on the velocity turuei in the lower diagram 'eereseni measured velotily in feet per second. VARIATION OF TIDAL VELOCITY IN SAN JOAQUIN RIVER NEAR ANTIOCH PLATE LXVI 12 1 2 3 " 4 5 6 7 ELEVATION OF WATER SURFACE AND MEAN VERTICAL SECTIONAL VELOCITY IN FEET PER SECOND September 22.1929 September 23,1929 9 10 1) Noon I E 3 4 5 6 7 8 9 10 II Midnight I a 3 4 5 6 7 8 9 10 II Noon 12 3 4 5 6 7 10 II 12 •D . UJ 3 J K 1 £ 10 „ ^ f O) *\ I » )! s ■^ } c o ^,«„ """^ e ■D i/J Ebb lide Water surface .".p?- -a^?^ "/rt- I ■■' ' ■■<« joffirn ■■ 4« l>» I ^'^^" ■>.\\\i>i VERTICAL SECTIONAL VELOCITY IN FEET PER SECOND riocd tide i„ iirtftcf.i •W" /.■■ // E.IJE. \ \ Ebb tide I / • ;' 4+- / '; \ -r-T- -'■^ flood tide ^„ , ■•yp^" ^_ ^ — ^1" (,.,, J. .//Ji #,. -fe — / Ebb tide Li" lK~ _,. ^-:^ %- ■■"■',*v" .■■/ \ ■■ il •1 , '/ \ .'I Velocity in_\\ i( y .^ i I Ebb tide W.. - 2::::j ■^= i- '"W." "i\;\". ">,}". _L toitf tfiii 9tii / u 4 3*— "-■^.N nVss ..■■i|\ W y» TT /N, 0,1.0,/ |0, ^.= JO OvM^ it -tr i- ^. -tr \ \ jS? Vso V*l -IS Tide sta^e o— Section CD NOTE: "^, Theletiers A,.A,.A,.B,.etc.on the upptrdiagram designate I/) rypical points of mean vertical velocity for each section com- l3 puicd from the veritcal velocity curves designaied by the ^/i same letters in the lower diagram Thus.ihe pomt marked Aj — c on the upper diagram is the mean vertical velocity of C9 toot I per second computed from the vertical velocity curve marked ^L A; in the lower diagram. The figures shown at each plotted (D pomt on the velocity curves m the lower diagram represent a> measured velocity in feet per second VARIATION OF TIDAL VELOCITY SACRAMENTO RIVER NEAR COLLINSVILLE cr b 01 10 3 D cr. C I*. < (JD < 0) < PLATE LXVI ♦A E*3 ■D C o o a> I/) I- a> a. + 1 +- OJ > 0) -2 c u 0) +4 ♦3 '♦2 ^ 5--0 m c .2 tj (U If) 15 o '+- u c 0) c m to D 0) ^^ o 75 c o «/) "to o c a> E Z3 •4— <0 •D to O to I d> 0) s- c c o I LU Lt. Bank RIVER CROSS SECTION 7*30 17+00 23+00 ♦ 5 E D 4- «D T3 to* to 3 10 •^-15 §-20 (D > UJ 25 -30 LEGEND — Tide sta^e — Section I — ., 2 3 NOTE: The letters A,. Aj. A3, B„ etc. on the upper diagram designate typical points of mean vertical velocity for each section com- puted from the vertical velocity curves designated by the same letters in the lower diagram Thus.the point marked A; on>the upper diagram is the mean vertical velocity ot 0.3 toot per second computed from the vertical velocity curve marked A7 in the lower diagram. The figures shown at each plotted point on the velocity curves in the lower diagram represent measured velocity m feet per second VARIATION OF TIDAL VELOCITY IN SACRAMENTO RIVER NEAR COLLINSVILLE •95— p. 202 ;>« • e s '8 U-.- - £ rr o 3 3 O (1) m U > 5 lU -♦ rT<5 1 -i J 0> < 1 .»_ ii m o _} o f^. -«•' ^ (V) er> u ^ c ¥ ' « s c 2 r- 1/5 o t > C3l 600 a> L. VI OJ TO ^500 k. ^ ■^ ■> *-o c_> t: 400 o o. '_ VI o m g 300 (-0 o 200 Noon 3 Au0. 18,1929 2 A 6 8 10 Midnight 2 Aug. 19, 1929 4 6 6 10 Noon LEGEND — Tide stage RIVER CROSS SECTION 5*10 l?»30 I9»80 = Section N9 I » Section N2 2 ■> Section N9 3 VARIATION OF SALINITY AND TIDAL VELOCITY IN SAN JOAQUIN RIVER NEAR ANTIOCH \ 206 DIVISION OF WATER RESOURCES velocity at the three different stations in the two river cross sections vary quite uniformly, with only slight dift'erences in the amounts at any particular time. It is evident that, for all practical purposes, the variation of salinity throughout a large river channel is a uniform one and, hence, observations at one point or at one section in a channel may be considered in general to be representative of an entire channel-. The relation between salinity and tidal velocity perhaps is shown more clearly by the graphs presented on Plate LXIX, "Variation of Salinity and Tidal Velocity with Depth." On these graphs the observed salinity has been plotted directly against simultaneous measurements of velocity at identical points. The upper and lower diagrams present data from typical measurements on the Sacramento and San Joaquin rivers respectively. The data have been plotted for observations at various depths at ten-foot intervals from surface to bottom at one station in each of the sections used on the Sacramento and San Joaquin rivers. The variations indicated are similar for each depth. The relation of mean salinity and mean velocity in the vertical section is shown for each station by the heavy' solid line on each graph. As shown by these mean relations, the maximum and minimum salinities during a tidal cycle occur approximately at the time of slack water or when there is no current either upstream or downstream. The curves indicate the cyclic character of the variation of both tidal velocity and salinity during a tidal cycle. Variation of Salinity with Tidal Flow. From the above demonstrations of the direct relation that exists between salinity and tidal velocity, and the inter-relations of these to the rise and fall of the tide, it is evident that tidal flow is a basic factor affecting the variation of salinity. It is a factor entirely inde- pendent from stream flow and has an effect of equal importance to stream flow on the advance and retreat of salinity. As the tides rise and fall in flood and ebb, tidal floAvs of varying magnitude occur, the pulsating action of which cause a mixing and diffusion of the more saline waters from points downstream with the fresher waters upstream. This action of the tides exerts at all times a positive and continuing tendency to push the more saline waters from downstream to points farther upstream in the tidal basin. Opposed to this action, stream flow into the basin is at all times exerting a tendency to push the saline waters to points farther downstream in the tidal basin. It is the relative magnitude of these two opposite and opposing forces which governs the advance or retreat of salinity at any point in the tidal basin. The effect of tidal action and tidal flow on the variation and advance and retreat of salinity is well illustrated by the data pre- sented on Plate LXX, "Variation of Salinity with Tidal Action and Stream F'low at Antioch, 1929." On this plate, the record of salinity at Antioch is graphically shown for the period July to December, 1929, while in parallel diagrams are shown detailed data covering all of the basic factors affecting the variation of salinity at this point. These: basic factors include stream flow into the delta, consumption of water in the delta above Antioch and tidal flow at Antioch. The record of high and low stages of the tide at Antioch is also shown. The upper- PLATE LXIX velocity SACRAMENTO RIVER CROSS SECTION 7*30 I7»00 23»00 1 / ^ .0 c izo o. a L 4>' VI mi y Wl / •> / 30 L NOT E: Number I indicates beginning of survey " 21 " end •• " ft. LEGEND Mean salinity and velocity Salinity and velocity at depth of 1 foot . ^» '• '< »» '• 10 feet 20 560 580 ' 2 feet from bottom Salinities and velocity as measured in section 1 of Sacramento River cross section. nd velocity _l_ 480 500 LtBank SAN JOAQUIN RIVER CROSS SECTION 5+10 12*30 19*80 NOTE: Number I Indicates be^innin^ of survey ». 25 " end « " LEGEND Mean salinity and velocity Salinity and velocity at depth of I foot 10 feet 11 « «• «• 20 " »• M •• " 30 " •« « " " />0 »• " " 2 feet from bottom Salinities and velocity as measured in section I of San Joaquin River cross section. VARIATION OF SALINITY AND TIDAL VELOCITY WITH DEPTH I'LATB LXIX SACRAMENTO RIVER NEAR COLLINSVILLE SECTION N9I SURVEY N2I8 SEPT. 16-17.1929 2 2A0 260 280 300 320 340 360 380 MO 420 440 460 480 500 520 540 560 580 Salinity in parts of chlorine per 100,000 parts of water SAN JOAQUIN RIVER NEAR ANTIOCH SECTION N9I SURVEY N9I8 AUG. 18-19,1929 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 Salinity in parts of chlorine per 100,000 parts ot water SACRAMENTO RIVER CROSS SECTION 7*30 17*00 23*00 NOTE; Number 1 Indicates beginning of survey " 21 " end " *• LEGEND Mean salinity and velocity Salinity and velocity at depth of 1 foot • lOfeet " " 20 " ' 2 feet from bottom SaliniTies and velocity as measured in section I of Sacramento River cross section. SAN JOAQUIN RIVER CROSS SECTION 1 5*10 12*30 19*80 Lt-Bank •.-20 I / ^*— - - 1*^ '. J-. } £ \ '"'^^^ ^" / ^40 J NOTE: Number I Indicates beginning of survey " 25 •• end •• '• LEGEND ' Mean salinity and velocity Salinity and velocity at depth of I foot >• " iOfset ., .. 20 •• .. .. 30 •• .. .. 40 " 2 feet from bottom Salinities and velocity as measured in section I of San Joaqui'n River cross section. VARIATION OF SALINITY AND TIDAL VELOCITY WITH DEPTH S099.i— p. 20(J PLATE LXX CONSUMPTIVE USE Of WATER IN SAN JOAQUIN RIVEIR DELTA ■I I Tl- ' ' • ' .... r-TT-i" ri'i 1 ' ' ' ' 1 1 1 1 .... .... .... .... .... .... 1 ' i 1 I . 1 1 1 1 -L.l 1 1 . 1 1 1 1 1 1 1 1 , , , , 1 1 1 1 1 1 1 1 1 1 1 1 i 1 I 1 1 1 1 1 1 1 1 1 1 ■ ■ 1 1 ■ ■ 1 1111 1 1 1 .L.J- .ill STREAM FLOW INTO SAN JOAQUIN RIVER DELTA VARIATION OF SALINITY WITH TIDAL ACTION AND STREAM FLOW ANTIOCH ' in' T 1 r m i S .7.1 S. fr =1 CD I '. P I, I I I I, t ^ 3 — ■ - i m i mm a < El w^ VARIATION AND CONTROL OF SALINITY 207 most diagram shows the variation of estimated consumptive use of water in the San Joaquin Delta above Antioch. The next diagram below shows the stream flow into the San Joaquin Delta, including inflow of the San Joaquin River and its main tributaries and also the flow from the Sacramento River into the San Joaquin Delta. The light dotted line on this same diagram shows the estimated net stream flow in the San Joaquin River at Antioch, which represents the dif- ference between the gross flow into the San Joaquin Delta and the consumption in the San Joaquin Delta above Antioch. The third diagram from the top shows the variation of salinity at Antioch, the light dashed line showing the actual observed salinities from samples taken in the surface zone usually after high-high tide and the heavy solid line the estimated mean tidal cycle surface zone salinities cor- responding thereto. The lower diagram on the plate shows the com- puted tidal flow into and out of the San Joaquin Delta tidal basin past Antioch. The tidal flow was computed on the basis of the formulae previously presented. There is also shown on this diagram the accumu- lated net tidal cycle flow from the beginning of July to the latter part of September, which represents the successive accumulations of the net algebraic sums of the two flood and two ebb flows for each tidal cycle. It will be noted that the magnitude of flood and ebb tidal flows is directly related to the magnitude of tidal range as shown by the tide record in the diagram immediately above, and varies between maximum and minimum values reached at intervals of about fourteen to fifteen days. The data show that the variation of salinity at Antioch during this period is due to the combined effect and relative magnitude of the net stream flow and the flood and ebb tidal flows passing Antioch. On July 1, the salinity at Antioch was about 25 parts with a net stream flow past Antioch of about 1500 second-feet. By July 20 the net stream flow had dropped to practically a zero quantity, remaining so until about the end of August. The net tidal cycle flow, which is approximately equal to net stream flow, was also practically zero during this period. From July 20 to the end of August, the mean salinity at Antioch increased to over 400 parts of chlorine per 100,000 parts of water. Inasmuch as there was practically no change in the net stream flow and the net tidal cycle flow during this period, it is evident that the increase of salinity must have been due to the pulsat- ing flow of the tide. It will be noted that the rate of increase in salinity varied with the magnitude of tidal flow. Thus, from July 1 to July 10, the salinity rapidly increased from about 25 to over 100 parts in parallel with the rapidly increasing magnitude of tidal flow during this period. From July 10 to about July 15 or 16, the salinity remained about the same or, if anything, decreased, corresponding to a simul- taneous decrease in magnitude of tidal flow. There then followed another period of greater rate of increase in salinity coincident with an increasing magnitude of tidal flow, with the salinity reaching 200 parts about July 25. Similarly the record of increase in salinity at Antioch may be seen to be in sympathy vnth. the varying magnitude of ebb and flood tidal flows passing Antioch. After the maximum salinity was reached about September 1 to 5, the decrease and retreat of salinity was exceedingly slow during the next 15 days, even though 208 DIVISION OF WATER RESOURCES the net stream flow past Antiocli p:radiial]y increased to abont 2000 second-feet during this period. After September 20, the record of salinity shows a definite trend downward with a gradually increas- ing stream flow. However, the effect of pulsating tidal flow in defi- nitely retarding the decrease of salinity or even temporarily increasing the salinity at about 14 day intervals when the tidal flow was at a maximum, is evident during this retreat period. Although the net stream flow past Antioch had reached about 4000 second-feet about November 1 and continued at about this rate until December 10, salinity averaging about 100 parts continued to remain at Antiocli until a large increase in stream flow starting about December 10 carried the saline water out of the delta entirely. If salinity in any degree is once present at any point in the tidal basin, these data indicate that a larger amount of stream flow is required to effect a decrease in salinity than would be required to prevent salinity of the same degree from increas- ing at the same point. This will be more fully referred to in a later portion of the report. It is not a necessary part of the conditions giving rise to saline invasion and increasing salinity at any point in the tidal basin that the net stream flow should drop to zero as it did at Antioch in 1929. In a year like 1927, the records indicate that there was at all times a net flow doAvnstream at the confluence of the Sacramento and San Joaquin rivers. Nevertheless, salinity increased at Collinsville and Antioch and advanced into the lower delta in that year. Thus, if the net stream flow is not sufficient to counteract the force exerted by the pulsating tidal flows tending to push saline water upstream, saline invasion will occur. However, if net stream flow is zero or is actually negative in quantity, it is evident that the effect of tidal action without any repelling force of stream flow would be increased. It is under condi- tions of negative net stream flow at the lower end of the delta that the more abnormal invasions of salinity such as in 1924 have occurred. The study demonstrates that tidal flow has a direct effect upon the variation of salinity and that tidal action is a basic factor of equal importance to stream flow governing the rate and extent of advance and retreat of salinity. The positive and continuing effect of tidal action, tending always toward pushing saline water upstream, will always result in an increase and advance of salinity unless the stream flow is of sufficient magnitude to counteract the forces exerted by the pulsating tidal flows. Tidal Diffusion. The magnitude of advance or retreat of salinity during a par- ticular time interval is measured by the volume of water in the channel or channels through which salinity of a particular degree has traveled. This total amount of advance or retreat is due to the com- bined effect of tidal action and net stream flow in the particular channel section. The effect of tidal action on the advance or retreat of salinity during a particular time interval is represented by the difference between the total volume of channel through which advance or retreat takes place and the total volume of net stream flow passing the section during the same period of time. It is the result of the pulsating tidal flows, accompanied always by the positive and con- VARIATION AND CONTROL OF SALINITY 209 tinning tendency to mix the generally more saline waters from down- stream with the fresher waters upstream. This effect of tidal action has been designated as "Tidal Difl'usion." The magnitude of tidal diffusion in any channel section of the tidal basin varies with the magnitude of tidal flow passing the par- ticular section. The effect of tidal diffusion in any time interval on the magnitude of advance or retreat of salinity in any channel section depends upon the volume of channel through which diffusion takes place, and upon the amount of net stream flow tending to oppose the same. Tidal diffusion is always directed upstream during both advance and retreat of salinity. However, the net stream flow may be either upstream or downstream at any particular section in the tidal basin, depending at a particular time on the relative magnitude of stream flow into the basin and of water extractions from the basin above the section. The theory evolved for the relation between the magnitude of advance or retreat of salinity and the basic factors of tidal diffusion and net stream flow governing the same, is expressed by the following formulae : Let C = the total amount of advance or retreat of salinity in a par- ticular channel section, expressed as the volume of channel through which salinity of a particular degree advances or retreats during a particular time interval. D = tidal diffusion, or the effect of tidal action on the total amount of advance or retreat of salinity (expressed in terms of channel volume) during the same time interval. S = the net stream flow passing the particular channel section during the same time interval. Then, C = D ±: S (1) And D = C=pS (2) The above relation evolved between advance or retreat of salinity, tidal diffusion and net stream flow is the most important result of this investigation. The fundamental relation expressed by the formula affords an adequate basis for a complete understanding of the phenomena of adA'ance and retreat of salinity. It furnishes the basis for the determination of the amount of stream flow required for control of salinitv. \ ^^ *■' From equation (1), it is evident that, if the net stream flow "S" is downstream and equal in magnitude to tidal diffusion "D," the advance or retreat of salinity "C" will be zero. If, however, the magnitude of tidal diffusion is greater than the net stream flow even though the latter be in a downstream direction, advance of salinity will result therefrom. If tidal diffusion is smaller in magnitude than net stream flow downstream, there will be retreat of salinity. Finally, if the net stream flow is negative or upstream, both stream flow and tidal diffusion are acting in the same direction and hence, for any given degree of salinity, the maximum advance of salinitj'' will occur. It is under this latter combination of conditions which have occurred fre- quently during the period of low stream flow in the last ten years or more that the greatest degree and extent of saline invasion has occurred in the upper bay and delta channels. 14—80995 210 DIVISION OF WATER RESOURCES Magnitude of Tidal Diffusion — Thn magnitude of tidal diflfusiou lias been determined from tlie relations shown in e(}nation (2) by the use of the available data on stream flow, salinity and channel volumes. The net stream flow at any particular section was computed from the records of stream flow into the delta, reduced by the estimated amount of water consumed above the section. The channel volumes for the sections of channel for which diffusion was computed were compiled from the hydroo-raphic surveys of the United States Army Engineers previously referred to in describing the com]nitations of tidal volumes. These channel volumes are graphically sliown on Plate LXXI, "Channel Volumes in Suisun Bay, Sacramento and San Joaciuin Rivers." The volumes are accumulated with distance upstream from the lower end of the delta near Collinsville for the two river channels and from Army Point to the mouth of the river for Suisun Bay. Separate graphs are sliown for volumes below various levels for each foot of elevation. The records of salinity for the period 1920 to 1929 provided the necessary data for determining the time re(}uired for various degrees of salinity to advance or retreat through a particular channel volume. Tidal diffusion has been computed for several sections in the tidal basin from Bulls Head Point as far upstream as Emmaton and Jersey. The chan- nel sections selected comprise the following : Bulls Head Point to Bay Point, Bay Point to 0. and A. ferry, 0. and A. ferry to Collinsville, Collinsville to Antioch, Collinsville to Mayberry Slough, Collinsville to Emmaton, Antioch to Curtis Landing, Antioch to Jersey, IMayberry Slough to Emmaton, Emmaton to Three Mile Slough. For the sections above Collinsville, the combined channels of the Sacramento and San Joaquin rivers were used in computing tidal diffusion quantities. The detailed method used for the computations of tidal diffusion during advance of salinity is described briefly as follows : For any assumed degree of salinity, the time interval required for salinity of this degree to advance from the lower to the upper end of each of the sections was obtained from the salinity records of the regular observation stations. These salinity records were first reduced to mean tidal cycle surface zone salinity. The values of mean salinity for each year of 'record were then plotted on an appropriate scale and smooth curves drawn to average the points. These graphs of mean salinity for the various key stations are shown on Plates LXXII and LXXin, "Estimated Mean Surface Zone Salinity." Time intervals for various degrees of salinity to advance from the lower to the upper end of each section were taken from these curves. Having determined the period of time for tho' advance of a particular degree of salinity, the net stream flow passing the section during the same period of time was then com]:)uted in acre-feet as the difference between the total inflow into the basin and the consumption of water above the par- ticular section. The total magnitude of advance was computed as the volume of channel in acre-feet between the two ends of each section. This volume was taken from the curves shown on Plate LXXI, using the mean water level during the period of advance considered. The total tidal diffusion in acre-feet during the particular period of time con- sidered was then computed by equation (2) using the total volume of channel through which the advance occurred and the total net stream flow, due regard being given to the proper algebraic signs of the quan- PLATE LiXXI SUISUN BAY JN E to B- -1 r SOUTH ARM OF SUISUN BAY -Bay Point to lower end Chain Island ■ Ml eons referred to U S.GS.datum. y4 ^ ■2-2 ^> fcs L. 3 " Oi o ^ IL _l o < f <* C5 ",1 40 4-4 48 50.3 52 Cice in miles from the Golden Gate 56 CHANNEL VOLUMES IN SUISUN BAY. SACRAMENTO AND SAN JOAQUIN RIVERS 210 DIVISION OF WATER RESOURCES Magnitude of Tidal Diffusion — Tlio magnitude of tidal diffusion has been detennined from tlie relations shown in efjuation (2) by the use of the available data on stream tlow, salinity and ehannel volumes. The net stream flow at any particular section was computed from the records of stream flow into the delta, reduced by the estimated amount of water consumed above the section. The channel volumes for the sections of channel for which diffusion was computed Avere compiled from the hydrographic surveys of the United States Army Engineers previously referred to in describing the computations of tidal volumes. These channel volumes are graphically sliown on Plate LXXI, "Channel Volumes in Suisun Bay, Sacramento and San Joaquin Rivers." The volumes are accumulated Avith distance upstream from the lower end of the delta near Collinsville for the two river channels and from Army Point to the mouth of the river for Suisun Bay. Separate graphs are shown for volumes below various levels for each foot of elevation. The records of salinity for the period 1920 to 1929 provided the necessary data for determining the time required for various degrees of salinity to advance or retreat through a particular channel volume. Tidal diffusion has been computed for several sections in the tidal basin from Bulls Head Point as far upstream as Emmaton and Jersey. The chan- nel sections selected comprise the following : Bulls Head Point to Bay Point, Bay Point to 0. and A. ferry, 0. and A. ferry to Collinsville, Collinsville to Antioch, Collinsville to Mayberry Slough, Collinsville to Emmaton, Antioch to Curtis Landing, Antioch to Jersey, Mayberry Slough to Emmaton, Emmaton to Three Mile Slough. For the sections above Collinsville, the combined channels of the Sacramento and San Joaquin rivers were used in computing tidal diffusion quantities. The detailed method used for the computations of tidal diffusion during advance of salinity is described briefly as follows : For any assumed degree of salinity, the time interval required for i salinity of this degree to advance from the lower to the upper end ; of each of the sections was obtained from the salinity records of the j regular observation stations. These salinity records were first reduced ' to mean tidal cycle surface zone salinity. The values of mean salinity for each year of 'record were then plotted on an appropriate scale and smooth curves draAvn to average the points. These graphs of mean salinity for the various key stations are shown on Plates LXXII and LXXllI, "Estimated Mean Surface Zone Salinity." Time intervals for various degrees of salinity to advance from the lower to the upper end of each section were taken from these curves. Having determined the period of time for tlie advance of a particular degree of salinity, the net stream flow passing the section during the same period of time was then computed in acre-feet as the difference between the total inflow into the basin and the consumption of water above the par- ticular section. The total magnitude of advance was computed as the volume of channel in acre-feet between the two ends of each section. This volume Avas taken from the curves shoAvn on Plate LXXI, using the j mean Avater level during the period of advance considered. The total tidal diffusion in acre-feet during the particular period of time con- sidered Avas then computed by equation (2) using the total volume of channel through AA'hich the advance occurred and the total net streai flow, due regard being given to the proper algebraic signs of the quan-j PLATE LXXI ;300 C o ^ 200 O 100 > SACRAMENTO RIVER CHANNELS ABOVE LOWER END OF CHAIN ISLAND, NEAR COLLINSVILLE *-200 (U r 'feioo 1/) Q) T3 C C C tu 03 JLl 3 O o 1 jerry 1 c o fl) E E - r i 1 1 i J^-'-'-rJ 1 = > -^ 2 1 1 — o in 1 -Rio Vista ' Bridge = — Junction Pt ^Volume below elev -3,0 ft. - 1 4 8 12 16 20 Distance in miles above lower end of Chain Island, near Collinsville SAN JOAQUIN RIVER CHANNELS ABOVE LOWER END OF CHAIN ISLAND NEAR COLLINSVILLE 1 1 1 1 : 1 i I 1 1 1 1 1 1 1 1 1 1 1 1 i '''',-.5.0 - «, ^ ^ S^''--''' ;^^ '1,0 - ;';I---l,0 - - :3 ;r^f*- _ -^ 1, . . 1 1 — ^ — 1 — 1 E w 1 1 1 —Blakes Landirij 1 1 1 Distance in miles above lower end of Chain Island, near Collinsville SUiSUN BAY ■5 300 (J SUISUN BAY -.^rmy Point to Bay Point SOUTH ARM OF SUISUN BAY Bay Point to lower end Chain Island - -> 36 40 44 48 50.3 52 Distance in miles from the Golden Gate NOTE: ^11 elevations referred to U.S,GS. datum. 80996— p. 210 56 CHANNEL VOLUMES IN SUISUN BAY, SACRAMENTO AND SAN JOAQUIN RIVERS PLATE LXXII BULLS HEAD POINT -1 — r 1200 O 800 o o o o — 600 £ 400 ^ 1200 1000 Jan. Feb. Mar. Apr. May June July Aug Sept. Oct. Nov. Dec. O&A FERRY 600 > < 400 200 Jan. Feb. Mar. Api Sept, Oct. Nov. BAY POINT 1200 800 600 1000 Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. COLLINSVILLE 400 200 Apr. May June July Aug. Sept. Oct. Nov. 80995 — p. 210 ESTIMATED MEAN SURFACE ZONE SALINITY PLATE LXXIII MAYBERRY 600 ro 400 o o °- 200 o I 1 1 1 1 1 - - - 1929^ \- V 1 1 1 1 EMMATON n — r SACRAMENTO RIVER STATIONS THREE MILE SLOUGH 1 1 1 1 1 1 1 ) 1 1 1 1 - 1924^ , y" - - / / 1926^0 / . \ N N V \.--y.l9Z0 '\^ - 1/ 1/ y/zsX \ \ 1 .i^f^^^,>j^'iiS^'^=j^^^^ — r-^^rt=^iP^+ — -^--K. u July Aug. Sept. June July Aug. Sept. Oct Nov. June July Aug. Sept. Oct. Nov. 2 jc o in ANTIOCH SAN JOAQUIN RIVER STATIONS CURTIS LANDING 800 ^ 200 200 1 1 1 1 1 1 1 1 1 1 i 1 - - - - - ^ ^192 i - ^\ \ 1 1 1 \^ ^1 - 1 1 1 1 ' 600 400 eoo RIO VISTA 1 1 1 1 1 1 1 1 1 1 - '?i-. - / r926 ' i^ \ y i92#\ \ — 1 ^' ^V-^'< .1928 .'925 i^v. June July Aug Sept, Oct. JERSEY 1 1 1 1 1 1 /S924 I 1 - / / f t f / / 1926^ - v^ / \ \ - / — -t^sS \ - June July Aug. Sept. Oct. Nov. Dec. June July Aug. Sept. Oct. Nov July Aug. Sept. Oct. Nov Dec. ESTIMATED MEAN SURFACE ZONE SALINITY ''9.'.— p. 210 i "AMMB TH«3SYAM Ml -- - V - . 1. ., -, 008 - 003 OOA OOS >08 ooa oo» $ -♦» o r» V) JQ O O O "o o -1 o. 3. o a' a si ■w^rrTM/ -, II II " t I — -1 0001 008 003 JO^ ^^■^SP^'V osQ vc'* o O c m B - OOS <^ 0) < > Vbf.'i VARIATION AND CONTROL OF SALINITY 211 titles. The total tidal diffusion was then divided bj^ the number of days in the particular time interval and a final figure obtained of tidal diffu- sion in acre-feet per daj- for the particular degree of salinity and in the particular section of channel considered. The computations were carried out in this manner for all of the above channel sections for different degrees of mean surface zone salin- ity, including 15, 25, 50, 75, 150 and higher values as necessary, in parts of chlorine per 100,000 parts of water. The salinity records available for all years from 1920 to 1929 were used in the computations. The results of these computations of tidal diffusion during the period of advance of salinity are graphically presented on Plate LXXIV, ' ' Tidal Diffusion in the Combined Channels of the Sacramento and San Joaquin Rivers," and Plate LXXV, "Tidal Diffusion in Suisun Bay." The actual computed tidal diffusion quantities are shown by the points plotted on these graphs, a separate legend being used for each year of record. The points are plotted using the mean values of surface zone salinity, for which the diffusion was computed, as ordinates and the computed amounts of tidal diffusion in acre-feet per day as abscissae. Smooth curves have been drawn averaging the plotted points. The amounts of tidal diffusion shown by the graphs may be considered to be mean values corresponding to average tidal flow, because the time intervals involved in the computations of total diffusion in various channel sections generally covered a long enough period to include all of the variations in tidal flow occurring in periods of seven to fifteen days. The magnitude of tidal diffusion would be greater or less than the computed mean values when the tidal flow were respectively greater or less than average. The amount of departure of the individual points during various years from the average curves drawn probably is due partly to inac- curacies in the basic data comprising records and estimates of salinity, stream flow, water consumption, and channel volumes. Changes in the tidal basin during the ten-year period of record covered by the study, affecting the magnitude of tidal flow, probably explain the dis- crepancies between the diffusion quantities computed for early years and those of more recent years. This will be referred to more fully in the latter part of this chapter. It is possible that the actual amount of consumption in the delta at the time of maximum saline invasion in the dry years such as 1920 and 1924 may have been less than the full demands estimated and used in the computations, because of cur- tailment of irrigation diversions. If this were true, the estimated negative net stream flows would be smaller and hence the diffusion quantities for the higher degrees of salinity during those years would be greater than estimated and the indicated negative values of diffu- sion possibly would be made positive. In plotting the curves, more weight has been given to the data for 1929 and more recent years than in the earlier years, because of the belief that the more recent data are more dependable and accurate, and because the relations for present conditions are of chief concern as related to remedial measures. Similar computations of tidal diffusion were made for the period of retreat of salinity. For any particular degree of salinity, it was found that the computed amounts of diffusion for each channel section were somewhat greater during retreat than those computed for advance k 212 DIVISION OF WATER RESOURCES of salinity. The shape of the diffusion curves was practically the same as those shown on Plates LXXIV and LXXV. It appears that the proportional eft'ect of tidal action on the variation of salinity is greater when the salinity is being pushed do^vnstream by stream flow and retreating than when salinity is advancing upstream with stream flow resisting the same. The diffusion curves for the retreat period have not been presented because they are not related to the chief purpose of this study which is concerned with the factors governing advance of salinity and the means of preventing such advance. Therefore, the discussions and presentation of data which follow in regard to the relation of tidal diffusion to salinity and tidal flow, apply chiefly to tidal diffusion during advance of salinity. Variation of Tidal Diffusion with Salinity — The basic variation of tidal diffusion with degree of salinity for various channel sections is shown by the graphs on Plates LXXIV and LXXV. It is evident from these graphs that the magnitude of tidal diffusion varies with the degree of salinity, increasing from a minimum approaching zero for relatively high salinities to a maximum for low salinities. The empirical relations evolved from the actual data appear to be logical, inasmuch as it is reasonable to presume that, during a continuous advance movement of progressively increasing salinity in any reach of channel, the pulsating flow of the tides would impregnate progressively lesser volumes of channel with an increased degree of salinity in a particular interval of time as the saline content of the water already present gradually increased to greater degrees. Geograjihical Variation of Tidal Diffusion — A study of these graphs indicates that the magnitude of tidal diffusion for any degree of salinity varies considerably for different geographical locations of the channel sections considered. It will be noted that the amount of tidal diffusion for any particular degree of salinity increases for channel sections farther downstream. This variation is more clearly shown on Plate LXXVI, ' ' Geograph- ical Variation of Tidal Diffusion." This graph has been compiled from the curves shown on Plates LXXIV and IjXXV. The variation of tidal diffusion for different degrees of salinity from 15 to 1000 parts of chlorine to 100,000 parts of water is shown in terms of dis- tance in miles from the Golden Gate. The distances used for the points taken off the curves of tidal diffusion for the various channel sections correspond to the location of the center of mass of the channel volume in each section. Smooth curves have been drawn averaging the plotted points. The relations depicted on this graph demonstrate that the mag- nitude of tidal diffusion for any degree of salinity increases for points farther downstream. For example, the diffusion at Bulls Head Point for a degree of salinity of 100 parts of chlorine per 100,000 parts of water is about 94,000 acre-feet per day as compared to about 8600 acre-feet per day at Collinsville or in the ratio of about eleven j to one. For greater degrees of salinitj^, the difference is even more marked. Thus, for a salinity of 500 parts, the tidal diffusion at Bulls Head Point and Collinsville is in the ratio of about eighteen to one. Relation of Tidal Diffusion to Tidal Flow — The greater magnitude of tidal diffusion at downstream points as compared to upstream points PLATE LXXIV COLLINSVILLE TO EMMATON BOO 1 1 I 1 1 1 I • 1 600 It f 1 * 1 1 » - U>0 ' 1 l^e \\» 200 n - %\ " 1 1 — 1 xA «'^l A« I -4 4 of acre -feet per day 12 LEGEND o 1929 data ^ 1928 o 1927 i^ 1926 • 1925 • 1924 > 1923 htone 1922 4 1921 1920 TIDAL DIFFUSION COMBINED CHANNELS OF THE NTO 8c SAN JOAQUIN RIVERS PLATE LXXIV 0.a.A. FERRY TO COLUNSVILLE ^ 800 t ca a. C3 - •. 1 - 1- ' (A * 1 °'\ ' 4 - S "*" o" o 1 » tf 1 * i tt - c c ' ■ 1 '°>' ■^ lO Iff 1 1 COLUNSVILLE: TO ANTiOCH COLUNSVILLE TO MAYBEIRRY SLOUGH ' -to V * 20 24 28 32 36 4 8 Tidal diffusion in thousands of acre- feet per day 16 20 1000 aoo soo AOO 200 —~~[ 1 - • - - - \ - V - a> 1000 5 q o N o 600 COLUNSVILLE TO EMMATON 3 5i - • < L ■ 1 • - 1 % • ■ 1 ' °\. a ° A« •>A U "i •< 12 16 20 -4 U 4 Tidal diffusion in thousands o' acre -fee* per day ANTIOCh TO CURTIS LANDING - \ ■ N <. — 1 - ANTIOCH TO JERSEY MAYBERRY SL0U6H TO EMMATON '•J ~ i-v £1 •* \J H Tidal diffusion in thousands of acre -feet per day 800 — 1 — - 400 300 - - V — 1 -r^ - EMMATON TO THREE MILE SLOUGH b 1000 r w R N c_> O 600 t- 1- QJ 0) ^- \ I \1 *^-r if I i_£_ Trdal diffusion in thousands of acre -feet per day LEGtND o 1929 dBTi . 1928 ■ • o 1927 ' • A 1926 « • • 1926 • • • 1924 • • ■ 1923 •• None 1922 •• • 1921 •• 1920 <• TIDAL DIFFUSION IN THE COMBINED CHANNELS OF THE SACRAMENTO & SAN JOAQUIN RIVERS CHANNEL BETWEEN BULLS HEAD POINT AND BAY POINT .^ S 16 24 32 W AS Si E« Tidal diffusion in thousands of acre-feeT per day CHANNEL BETWEEN BAY POINT AND 0.&.A.FERRY I ! 1 1 1 1 1 1 1 1 ~T — 1 1 — v - \ - - ^. - >s^ ■^--.^ - 8 16 2« 32 40 18 Tidal diffusion in thousands of acre - feet per day LEGEND ' 1929 data : 1928 •• I 1921 " ■ 1926 •• TIDAL DIFFUSION IN SUISUN BAY : — j — I — 1 — 1 — I — I — r- 7~j 00*1 OOOI 0) 008 3" ,C5 ooa o -I 00* ^ -i" o_ a. u oos ^ ^')-r:^.oe }o 2bn6tfUofiJ ni noi^uTiib IsbiT Yflfl31 A Ji p nwA TWinq YAa M33WT3a J3MMAH3 "I — I — r- -T — I — \ — I — I — r-^ — I — ! — I — r ill! t- Mi I I ^ -T*- dc 8* OA f5 OOOI ^ AS ai 8 £1!; .<; VARIATION AND CONTROL OF SALINITY 213 PLATE LXXVI 96 88 80 72 0) QJ (/) XI C w O c o 3 64 56 48 40 32 24 16 1 — \ — r "1 — r -| — r "1 — r— r "1 — I — r NOTE Tidal diffusion of salinity between observation stations is plotted at the center of mass of the channel volume between stations. Points are mean values computed from data secured between 1920 and 1929 inclusive except as noted. Numbers on curves indicate mean surface zone salinity in parts of chlorine per 100,000 parts of water. 32 36 40 44 48 52 56 60 64 Distance in miles from the Golden Gate via Sacramento River GEOGRAPHICAL VARIATION or TIDAL DIFFUSION 214 DIVISION OF WATER RESOURCES in the tidal basin is to be expected because of the greater magnitude of tidal flow at points farther do\^^lstreanl in the tidal basin. Tidal diffusion of salinity is the result of the pulsating tidal flows and hence tidal diffusion increases with the magnitude of tidal flow. This is demonstrated by the graph presented on Plate LXXVII, "Relation of Tidal Diffusion to Tidal Flow." This graph has been prepared by plotting for the various key stations or sections the tidal flow during a tidal cycle against tidal diffusion for various degrees of salinity as taken from the curves on Plate LXXVI. Tidal flow, as directly related to tidal diffusion at any given section, is equal to the total A'olume of water which flows past the section into and out of the tidal basin above the section during a tidal cycle. It is computed as the arithmetical sum of the two flood and two ebb flows. Mean values of total tidal flow are used on the graph, corresponding to the mean range of the tide for each section. Effect of Recent Changes in Delta Tidal Basin on Saline Invasion. From the foregoing relations established between tidal action and saline invasion in the upper bay and delta, it is possible to make an approximate estimate of the effect of recent changes in the delta tidal basin on tidal flow into the delta and tidal diffusion of salinity affecting saline invasion. As previously described in this chapter, the recent changes within the delta, Avliich have modified the volume in the delta tidal prism, comprise the widening of the lower Sacramento River from Collinsville to a point above Rio Vista, the flooding of the lower end of Sherman Island, and the flooding of a previously reclaimed area lying south of Dutch Slough and the San Joaquin River. These changes have all had the effect of enlarging the volume in the tidal prism above the lower end of the delta. This has resulted in increasing the volume of tidal flow passing into and out of the tidal basin above all points from the lower end of the delta downstream through Suisun Bay. The curves presented on Plate LXXVII show the relation between tidal dift'usion for various degrees of salinity and tidal flow. The tidal flow used on these diagrams is based upon 1929 conditions in the tidal basin as computed from actual tidal prisms. The amounts of tidal diffusion were determined separately from actual records of salinity, stream flow into the delta, and estimates of con- sumption of water in tlie delta. It appears reasonable to assume that the relations established and sliown on Plate LXXVII would hold for the ditferent conditions in U\o tidal basin before these changes occurred, even though the rate of tidal movement in the lower Sacramento River channel probably has been increased to some extent by the deepening of this section of channel. It appears that the rate and character of tidal movement into the d(>lta basin as a whole, past the lower end of the delta at Collinsville, may be considered to be approximately the same both before and aftei" the changes took place. In other words, it is believed that the vertical limits of the tidal prisms in these sections of the tidal basin before the changes were made were probably about the same as those determined for present conditions. This is the chief element affecting the estimate of change in tidal flow, and it is believed that estimates of tidal flow for former years made on the basis of the present tidal prisms may be considered to be a fairly close approxi- VARIATION AND CONTROL OF SALINITY 215 PLATE LXXVII 96 88 80 "O l_ - " 1 \\ \ \ \ v" 1 g 1 s 3 MILES AE JERSEY 1 1 1 < \\ \ \ \ \ \ '' c \ \ - \\ \\ \ ' - \^ \ \ \ V\ \\' - \ \ ^^^ A^ \V^ J : ' \\ O^ \^ ^ 1^ "i^ r 1 1 1 1 1111 ! 1 1 1 1 [ 1 1 111! ^^^ fe N: 6 50 600 550 500 450 400 350 300 2 Mean tidal flow in thousands of acre-feet 50 RELATION OF TIDAL DIFFUSON TIDAL FLOW 216 DIVISION OP WATER RESOURCES mation. It has been demonstrated that the pulsating? tidal flow is the direct cause of the tidal diffusion of salinity and it appears reasonable to conclude that an increase of tidal flow past any section would have the positive effect of increasing^ the magnitude of tidal diffusion at that section. It is believed that the following estimates of increased tidal diffusion, based upon the application of the change in tidal flow to the relations on Plate LXXVII, may be considered to be a fairly close approximation of the true effect of these changes in the tidal basin. However, the quantities estimated should not be considered as being exact, but as a fair indication of their magnitude. Effect of Sacramento River Channel Enlargement — As previously stated, the enlargement of the Sacramento River channel from Collinsville to a point above Rio Vista has resulted in a progressive enlargement of the area in the tidal prism of about 3000 acres. With a mean tidal range of about three feet in this section of the tidal basin, this would result in increasing the volume in the tidal prism by between 8000 and 9000 acre-feet, and increasing the average total tidal flow passing points downstream by about 32.000 to 36,000 acre-feet. The actual change in tidal flow would not be this much, however, on account of the shape of the tidal prisms. (See Plates XL to XLV). It is esti- mated that the increase in total tidal flow resulting from this channel enlargement, at various downstream points, would be as follows: Collinsville 28,000 acre-feet 0. and A. ferry 32,000 acre-feet Bay Point 35,000 acre-feet Bulls Head Point 30,000 acre-feet Appljdng these increased amounts of tidal flow to the relations shown on Plate LXXVII, the following tabulation shows the estimated amounts of increased tidal diffusion resulting from this increased tidal flow: INCREASE OF TIDAL DIFFUSION RESULTING FROM SACRAMENTO RIVER CHANNEL ENLARGEMENT Mean tidal cycle surface zone salinity in parts of chlorine per 100,000 parts of water Estimated increase of tidal diffusion in acre-feet per day Collinsville 0. & A. Ferry Bsy Point Bulls Head Point 151 5,600 4,900 4,200 3,300 2,000 2,200 1,200 900 9,800 7,900 6,500 5,200 4,300 3,800 2,000 1,700 1,400 25 17,300 13,100 10,600 8,400 7,600 5,500 5,100 3,800 2,900 2,300 1.900 1,300 50 .. . -- 100 13,000 150. 10,200 200... - -- 9,400 300 6,300 400 - 4,800 50Q 4,000 600 . 3.800 700 3,300 800 - -- 2,800 900 2,200 It is of particular interest to note that the amount of tidal diffusion for a mean surface zone salinity of 100 parts of chlorine per 100,000 parts of water is increased at Collin.sville, at the lower end of the delta, by an estimated amount of 3300 acre-feet per day. VARIATION AND CONTROL OP SALINITY 217 Saline invasion through Suisun Bay and into the delta has also been affected by this elianuel enlargement due to an increased rate of advance of salinity resulting from the increase in amount of tidal diffusion for all degrees of salinity at points down stream from the delta. It is evi- dent from the formula previously presented on the relation between advance of salinity, stream flow and tidal diffusion, that the rate of advance of salinity for any degree would be increased with an increased amount of tidal diffusion. Thus, the time required for any degree of salinity to travel from the lower end of Suisun Bay to the lower end of the delta would be decreased. Hence, for any particular stream flow conditions, the channel enlargement of the lower Sacramento River has resulted in salinity arriving at the lower end of the delta earlier in the season than would have occurred before the enlargement was made. On the other hand, the rate of advance of salinity along the enlarged channel section of the lower Sacramento River would be decreased. Even with the greater amounts of tidal diffusion resulting from increased tidal flow, studies indicate that the enlarged channel volume would have the effect of increasing the length of time required for any degree of salinity to travel from Collinsville to Rio Vista. Therefore, although this channel enlargement has resulted in saline water arriving at the lower end of the delta at an earlier date than would have occurred before the enlargement was made, it has also resulted in delaying the advance of salinity to points farther upstream in the delta. The studies indicate that the increased and decreased rates of advance below and above Collinsville respectively would tend to balance each other in regard to the total time of travel of salinity from lower Suisun Bay points to Rio Vista and points upstream there- from on the Sacramento River. Effect of Flooding of Previously Reclaimed Lands — The flooding of the lower end of Sherman Island and tlie previously reclaimed area south of Dutch Slough and the San Joaquin River has had a similar effect to the enlargement of the lower Sacramento River channel in increasing the volume of the tidal prism, and hence the volume of tidal flow and amount of tidal diffusion at points downstream. The area flooded on lower Sherman Island comprises about 1800 acres, while that near Dutch Slough amounts to 2200 acres or a combined total of about 4000 acres. Based on a similar analysis to that presented for the change on the lower Sacramento River, it is estimated that the tidal flow past Collinsville has been increased by about 30,000 acre-:teet as a result of the flooding of these two previously reclaimed areas. The effect on tidal diffusion for any degree of salinity is, therefore, of about the same magnitude as that previously estimated for the channel change in the lower Sacramento River. It appears from these estimates that, if the flooded reclamations on the lower end of Sherman Island and in the vicinity of Dutch Slough were reclaimed and removed from the tidal prism, the amount of tidal diffusion at the lower end of the delta (Collinsville) would be decreased by about 3200 acre-feet per day, for a mean surface zone salinity of 100 parts, and that the net stream flow required to repel tidal diffusion of salinity at this degree at Collinsville w^ould be correspondingly decreased. 218 DIVISION OP WATER RESOURCES The flooding? of the lower end of Sherman Island has probably not affected the tidal flow past the Antioch section; and hence, it may be assumed that the increase in tidal diffusion at Antioch resulting from recent changes in the tidal basin would include only the Dutch Slough reclamation and a portion of the Sacramento Kiver channel enlarge- ment. The effect of the Dutch Slough reclamation itself would be an estimated increase in tidal flow past Antioch of 16,000 acre-feet per day. This would increase tidal diff'usion for 100 parts of mean surface zone salinity by 1600 acre-feet per day. Tlie result of the lower Sacra- mento Eiver cJiannel enlargement at the Antioch section, is estimated to be an increased tidal diffusion of about 1600 acre-feet per day. Thus, if these changes had not occurred, the studies indicate that tidal diffusion at the Antioch section for 100 parts of salinity would be reduced by about 3200 acre-feet per day, and that the net stream flow for repelling tidal diffusion of salinity to this degree at this section would be correspondingly reduced. Moreover, if the previously reclaimed area near Dutch Slough were again reclaimed, the studies indicate tliat the net stream flow for preventing advance of salinity of 100 parts at the Antioch section might be decreased by about 1600 acre-feet per day. Effect on Tidal Diffusion — In connection with the presentation of the tidal diffusion curves on Plates LXXIV and LXXV, it was pointed out that changes in the tidal basin during the period since 1920 might explain the discrepancies between the computed values of tidal diffu- sion in the earlier and later years of record. Inasmuch as the forego- ing studies indicate that the changes in the tidal basin since 1920 have increased tidal diffusion at the loAver end of the delta and points downstream it appears that this offers a reasonable explanation for the diffusion quantities, as computed for such years as 1920 and 1921, being generally smaller than those for the more recent years. Effect of Stockton Ship Canal — The results of these studies indicate that any enlargement in tidal prism volume resulting from tlie con- struction of tlie Stockton Ship Canal would have a similar effect of increasing the amount of tidal diffusion at points lower down in the delta, and, hence, of increasing to some extent the stream flow required for control of salinity in the lower delta. Studies have been made of tlie proposed construction plans for this work. For the main work along the upper San Joaquin River, it appears that tlie widening of old channels and the construction of new channels will be largely offset by cutting off and filling in some of the existing channels and submerged areas. If the volume in the tidal prism is not materially increased by the work actually carried out in this section of the project, it would have no effect on salinity conditions. The widening of New York Slough, Avhicli is a part ol" this deep-water project, may have the effect of increasing tidal diffusion below the lower end of New York Slough and possibly increasing to some extent the degree of saline invasion in the vicinity of Pittsburg and Antioch. No studies have been made to estimate the possible effect of this particu- lar channel enlargement. VARIATION AND CONTROL OF SALINITY 219 CHAPTER V CONTROL OF SALINITY The primary purpose of the investigation of salinity is the deter- mination of an effective means of controlling salinity and preventing the harmful effects of saline invasion in the upper bay and delta region. This is the objective toward which all the activities and studies of the investigation have been directed. The conditions brought about by saline invasion in the upper bay and delta region are of serious concern. The frequent repetition of saline invasions of considerable magnitude and the possibility of even more prolonged and more extensive invasions than have heretofore occurred may result in permanent injury to the rich agricultural lands in the delta. The saline menace has tended already to depreciate land values in the delta. The conditions have been the cause of expensive water right litigation and probably will lead to even more serious and expensive litigation between the delta interests and upstream water users, unless water supplies free from saline invasion are provided for the delta. The industries in the upper bay region have been curtailed in their use of cheap fresh-water supplies from the lower river and are experiencing considerable difficulty and expense in obtaining dependable and adequate fresh-water supplies for their needs. Remedial measures are desirable and necessary to protect the delta and provide adequate and dependable fresh-water supplies for the needs of the delta and upper bay region. One method for controlling salinity would be the provision of a physical barrier to obstruct the entrance of saline water into the upper bay and delta channels. It is not within the province of this report to consider this method of control. The physical and economic aspects of a salt water barrier are presented in detail in other reports.* The intensive investigations and studies presented in the foregoing chapters point to an obvious solution of this entire salinity problem ; namely, the control and preventon of saline invasion into the delta by means of stream flow. The records and studies of the variation of salinity and stream flow demonstrate that the more extensive saline invasions into the delta channels have been due to deficiencies in stream flow entering the delta. It has been shown during the period 1920 to 1929 that the stream flow entering the delta in the summer months often has been insufficient to take care of even the comsumptive demands of crops and other uses in the delta. It has been under such conditions of deficient stream flow that the maximum invasions of salinity have occurred. During the years 1921 to 1923, inclusive, and 1927, the stream flow into the delta during the summer months was just about sufficient to take care of the consumptive demands therein. In those years, the * Bulletin No. 22, Report on Salt Water Barrier Below Confluence of Sacra- mento and San Joaquin Rivers, California — 2 Vols., Division of Water Resources, 1929. Bulletin No. 28, Economic Aspects of a Salt V^ater Barrier Below Confluence of Sacramento and San Joaquin Rivers, Division of Water Resources, 1931. 220 DIVISION OP WATER RESOURCES deprroe and extent of saline invasion into the delta were relatively small. At the time of maximum extent of invasion, water with a salinity of 100 parts or more of chlorine per 100,000 parts of water extended only as far up the Sacramento and San Joaquin river channels as a mile below Emmaton and two miles below Jersey, respectively; while the salinity upstream from these points was considerably less, the water being practically fresh in most of the delta. The maximum extent of invasion in 1925 was but slightly greater. Thus, in these five years, over 95 per cent of the delta had a fresh-water supply suitable for agri- cultural purposes at all times ; and for the greater portion of the season, practically all of the delta had a fresh-water supply entirely free from saline invasion. The records show that when the stream flow into the delta has been sufficient to take care of the consumptive demands of the delta, saline invasion has been of such small degree and extent as to be of little consequence to the delta. It is evident, therefore, that the primary requirement for control and prevention of the invasion of salinity into the delta is the furnish- ing of a sufficient water supply flowing into the delta to fully satisfy the consumptive demands of crops together Avith the natural losses by evaporation and transpiration from vegetation. After this primary requirement is satisfied, additional water is necessary to repel tidal action and the tidal diffusion of salinity resulting therefrom. The amount of additional water required varies with the location at which control is sought or desired and the degree of salinity desired to be controlled at the particular location. Stream Flow Required for Control of Salinity. The stream flow required for the control of salinity at any point in the tidal basin is equal to the amount of tidal diffusion at the par- ticular point with the degree of salinity for which control is sought or desired. The fundamental relation demonstrated in Chapter IV between stream flow, tidal diffusion and advance of salinity furnishes the basic law of control. This law is expressed by equation (1) as follows : C=D — S Where C == the magnitude of advance of salinity for any particular degree of salinity S = the net stream flow D = tidal diffusion for any particular degree of salinity. It follows mathematically that if the advance "C" is zero, then "D" must be equal and opposite to "S." In other words, if the net stream flow downstream at a particular point is equal in magnitude to the tidal diffusion which is always directed upstream, there will be no advance of salinity. Hence, for control of salinity by stream flow at any particular point and for any particular degree of salinity, a net stream flow downstream at the particular point must be provided equal in magnitude to the amount of tidal diffusion with the particular degree of salinity for which control is sought or desired. The tidal diffusion curves previously presented in Chapter IV provide the basic figures for the determination of the amount of net stream flow required at VARIATION AND CONTROL OF SALINITY 221 any desired point or degree of control. (See Plates LXXIV, LXXV and LXXVI.) Net Control Flows — The net stream flow required for control of salinity to various degrees from Bulls Head Point to Three Mile Slough and Jersey is graphically presented on Plate LXXVIII, ' ' Net Stream Flow for Control of Salinity at Points in Suisun Bay and Lower Delta." The curves on this plate are identical with the curves on Plate LXXVI, on which the geographical variation of tidal diffusion is shown. Desired Point and Degree of Control of Salinity — The point and degree of control of salinity by stream flow must be based primarily upon a consideration of the needs of the agricultural interests in the delta and the industrial, municipal and agricultural interests in the upper bay region. It would be desirable to adopt such measures of control as would most effectively and, at the same time, most economically provide for the present and ultimate needs of these water users. At the same time, consideration must be given to the general plan for the develop- ment and utilization of the State's water resources and the amount of additional water supplies created thereby in relation to the needs not only of the delta and upper bay region but also of the Sacramento and San Joaquin valleys. Finally consideration must be given also to the practical limit of control which is possible of attainment by means of stream flow. The degree of control required is dependent upon the quality of water necessary for agricultural, industrial and municipal demands. For agricultural use with average conditions and crops in the delta, it has been assumed that water having a salinity of over 100 parts or more of chlorine per 100,000 parts of water would not be suitable for irrigation. Hence, if the invasion of salinity were controlled at the lower end of the delta so that mean tidal cycle surface zone salinity would not exceed 100 parts of chlorine per 100,000 parts of water near Antioch and be considerably less in amount upstream, the water supply in practically the entire delta would be satisfactory in quality for irri- gation at all times of the year and the lands and developments of the delta fully protected. There would be only limited areas of small extent in close proximity to Antioch for which a suitable quality of water might not be available in critically dry years for the irrigation ' of crops particularly susceptible to injury from salt. The water required for use in boilers and processes by industries and for general domestic use in the upper bay region must be much fresher in quality. The maximum salinity allowable for these uses I should not exceed 25 parts and preferably not over 10 parts of chlorine per 100,000 parts of water. In order to obtain water of as fresh a quality as 25 parts of chlorine per 100,000 parts of water (mean tidal cycle surface zone salinity), it will be seen by Plate LXXVIII that a net stream flow downstream would be required of 5600 second-feet at Antioch 7550 second-feet at Collinsville 11,600 second-feet at 0. and A. ferry 26,800 second-feet at Bay Point In addition to these net flows required at these points, the total stream flow provided into the delta would have to include the consumptive 222 DIVISION OP WATER RESOURCES PLATE KXXVIII 48 U 40 36 4,32 c o o w to -o c w D 24 o 5 20 o E a; iz 16 I/) +- (U 12 1 — I — r T — I — r "1 \ r -[ — I — r "1 — \ — r "1 — r NOTE Numbers on curves indicate degree of salinity control expressed as mean surface zone salinity in parts of chlorine per 100,000 parts of water 32 36 40 44 48 S2 56 60 Distance in miles from the Golden Gate via Sacramento River 64 NET STREAM FLOW FOR CONTROL OF SALINITY AT POINTS IN SUISUN BAY AND LOWER DELTA VARIATION AND CONTROL. OF SALINITY 223 demands above these several points, which for the delta itself varies from a rainimnm of about 400 second-feet in mid-Avinter to a maximum of about 3700 second-feet in mid-summer. As compared to these requirements for industrial and domestic needs alone, control of mean tidal cycle surface zone salinity to 100 parts of chlorine per 100,000 parts of water could be obtained with the following net stream flows : 3000 second-feet at Antioch 4300 second-feet at Collinsville 6£r00 second-feet at 0. and A. Ferrv 17,000 second-feet at Bay Point With this latter degree of control maintained near Antioch, the salinity would be considerably less upstream, and the channels of over 95 per.' cent of the delta would have fresh water suitable for both industrial and domestic use. Hence, fresh-water supplies of the purity required for industrial process and domestic use could be made available in the, delta channels, and not far distant from the upper bay region. It is evident that the necessary supplies of fresh water for industrial and domestic use along Suisun Bay could be more economically obtained by conveying fresh water in special conduits from points within the delta, than by means of controlling salinity by stream flow to points farther downstream than the lower end of the delta. For example, to control salinity for obtaining the necessary quality of water for industrial and domestic use down to 0. and A. ferry would require about 12,000 second-feet at least as compared with about 3000 second-feet necessary for maintaining fresh water in the delta channels or a difference of about 9000 second-feet. Even with control to this degree as far as 0. and A. ferry, the demands of industries and other users located farther downstream could not be furnished except by the construction of a conduit to carry water from the controlled fresh-water area to down- stream points. The greater part of the water used by the industries along Suisun Bay is for purposes of cooling and condensing. Most of these industries are now equipped with such cooling and condensing apparatus, pipes and fittings, as will provide the most economical service with the present supply of water available for this use. As far as this greater part of the water supply demands of the industries is concerned, it appears that the present water supply is satisfactory for this purpose. The cost of cooling water, including operation, maintenance and depre- ciation expenses, is small. If salinity were controlled to 100 parts of chlorine per 100,000 parts of water near the lower end of the delta, the water downstream would be less saline than under present conditions, especially in the upper part of Suisun Bay and in the vicinity of Pittsburg where the density of industrial development is the greatest. Corrosion would be reduced and the expense of cooling and condensing water decreased. The city of Antioch now obtains its supply from the San Joaquin Eiver, pumping therefrom when the water is suitable in quality and storing the same in reservoirs for use during the period when the water in the river becomes too saline for domestic use. In order to provide water of the freshness required for domestic use at Antioch at all times, the net flow required would be 6000 second-feet or more, or at 224 DIVISION OF WATER RESOURCES least double the amount required for the degree of control necessary for agricultural purposes in the delta. Therefore, it does not appear prac- tical to consider a degree of control sufficient to provide fresh water at all times in front of Antioch of the quality required for domestic use. It is certain, however, that control to the degree required for agricultural purposes in the delta would improve the saline conditions at Antioch. In the event that the city's needs increase still farther than present facilities provide, it would be entirely feasible to obtain additional supplies by diverting water through a conduit from farther upstream, possibly in combination with service to the- area south of Suisun Bay. Proposed Net Control Flow — Based upon the foregoing considerations, it is concluded that the most desirable and practical plan to adopt for •controlling salinity by means of stream flow would be a control at a point near Antioch sufficient to limit the increase of mean tidal cycle surface zone salinity to a degree not to exceed 100 parts of chlorine per 100,000 parts of water, and lesser degrees of salinity upstream. This would require a net flow of 3000 second-feet in the combined channels of Sacramento and San Joaquin rivers past Antioch. A quantity of 3300 second-feet has been adopted as the recommended amount of net control flow to be provided as a minimum flow in the combined river channels past Antioch into Suisun Bay. This would put the control point for a maximum d6gree of mean tidal cycle surface zone salinity of 100 parts of chlorine per 100,000 parts of water about 0.6 miles below Antioch. It is of interest to determine what the resulting mean salinities would be at other points in the delta and bay channels with this degree of control maintained near Antioch. This is shown in Table 27. For purposes of comparison and interest, the flows required for control of salinity to a degree of 25, 50, 100 and 200 parts of chlorine per 100,000 parts of water (mean tidal cycle surface zone salinity) also are shown, together with the resulting salinities at other points. This table thus presents a clear picture of the relative degrees of salinity control obtained at representative control points in the upper bay and delta wnth different assumed net control flows at these respective stations. In computing the figures shown in Table 27, the difference in consumptive demands above the several stations has been taken into account in estimating the resulting mean salinities for the assumed control flows. Of particular importance are tlie figures shown for the propo.sed control flow of 3300 second-feet Avhicli is recommended for adoption. "With this net flow maintained as a minimum past the Antioch section into Suisun Bay, the maximum degrees of mean tidal cycle surface zone salinity, in partes of chlorine per 100,000 parts of water, at various points in Suisun Bay and the delta are estimated as follows : Bulls Head Point 1200± Bay Point 700 0. and A. ferry 275 Lower end of New York Slough 225 Collinsville 150 Antioch 90 Emmaton 15 Jersey 10 VARIATION AND CONTROL OF SALINITY 225 Z o u u a: o u D J a < u< o _) o a: H z o o § o <: u H w H U Z o o o o s a 8 o > O w.s CO O I a o-2'g ^^ rt M o ld/5 ■^^ OOOOOiCOOO 00'-HcDa»0*"OCDOt>-'OOiOOOiCCM'^CDCM»— (*— « CO CM i-H 1-H t~» W3 CO -*< CO CM CO CM »-l »-i CM «-l 1-H CM i-" i-H lO lO o o ■«*< CM CM 1-t o oo »o 05 I-* CD -^ ooo CM t-i Oi OOOOiOOOiOOOOOOiCOOOOOOuOlO OOOW3CMu0CMCM40OCM'*ascC>i000»OOO»0CMCM COtCCD'^CO^COCM^H'^CM»-i CMi-i CM«-< OiCOOOOiOOOiCOiOOiOOO^OOOU^OOOO^OiO OCMOO^'-iCMOOt~*ait-f~-t>-OOCOt~^COOt-OOOiOCM'-t i-HOSi-iait^Oir^cOu3t-^«5'^OO^^COCMW3'^CMCMC^)'-< oo oo i-HO iOOOOOOOOOiOOOOOOOO t*t0CDO00e0^iOO1^^0i0»O»O»0OO OOi00i-HC>00t^OOit--50C0'*e0CMCM*-i ooooooo.ooooooooooooooooooooooooo OOOOOO^Ot^COiO^OOOOOOO^COOOOOOiOOOOOOOO OCOCOO(»COOSC00 05000CMCOr^C005lOW3COCDl/3COO C^'cO^CO .--T.-Hi-HCMCM>-HCO^iOCM'^"^t-^CO»Ct^CO^cOOr^i--Jt-r.--^ ^H .-H ,-1 CM CM CO -^ a> ^ rt fli "^ Ci3 ;a rt »g 5-^ 3:5 OOOkOOO^OOOU^CkOOiAOOOaOOOOUDOOOkOOOOU^OO o s o o J.2.§S -*^ -AJ -»J -^^ q s a a » & » & '- e i2 S ^3^^ ja^ U) M U CO 3 3 3 3 _o_o_o_o fc« k. bl Lh o o o o » » » fr « q; a> « . . . . 5222 bbbb = = =: = T3T3-0-OpE,pt,fc,fc S -IS -^ 'JS -^ ^ — — ^ ft ft fe ft TTvjsjt-ih-ncccGoooooooo.* . .cQeecses to CO CO CO !- a a "S'o Is KM nsQ 15—80995 226 DIVISION OP WATER RESOURCES It will be noted tluit, iiiulei- tlie proj^osed control, fresh water of suitable quality for industrial and domestic use would be maintained in the channels of the entire delta above Emmaton or Jersey. Gross Stream Flow Into Delta for Control of Salinity — In order to carry out successfully the proposed method of control by stream flow and maintain the net flow required for control at the lower end of the delta, the consumptive denuinds of the delta also must be provided. The con- sumption of Avater by evaporation and transpiration from marginal vegetation is a continuous although variable demand, reaching a maxi- mum rate in the summer months. Likewise, a considerable portion of the moisture used bj' crops on the delta lands is supplied by natural seepage into the islands. Hence, although irrigation by artificial diver- sions of water is essential to the successful production of most crt)ps in the delta, the consumptive use by crops is only partially subject to control. Moreover, irrigation supplies would be artificially diverted as long as water of suitable quality were available. Hence, the primar}^ essential for successful control of salinity by stream flow at the lower end of the delta would be the provision of adequate supplies to care for the full consumptive demands in the delta. The total stream flow into the delta required for the combined needs of consumptive use in the delta and salinitj' control varies with the consumptive demands during the irrigation season. At anj^ particular time during the season, the rate of inflow requii'ed is eqiud to the rate of consumption at the particular time plus the rate of net flow required for salinity control. The variation in rate of stream flow into the delta required to satisfy these combined demands, or what may be termed the "gross control flow," is best shown in the form of a graph. Plate LXXIX, "Gross Stream Flow Into Delta for Control of Salinity 0.6 Miles Below Antioch," shows the total gross inflow required throughout the season for various degrees of salinity control at the control section below Antioch. Each of the control curves plotted on this graph takes the same shape as the estimated curve of water consumption in the delta above the Antioch section. They have been obtained by adding to the curve of consumptive use the estimated net control flows required for various degrees of salinity control. The heavy curve shows the variation of gross control flow into the delta required for the proposed control of mean tidal cycle surface zone salinity to 100 parts of chlorine per 100,000 parts of water. As shown by this curve, the rate of gross inflow required for the combined needs of consum])tive use and proposed salinity control varies from a minimum of about 4000 second-feet at the beginning of Ajiril to a maximum of about 7000 second-feet in August. After reaching the maximum rate in August, the total requirement gradually decreases to about 4000 second- feet in December. As a means of checking the essential accuracy of this estimate of gross control flow, it is of value to compare the actual records of stream flow into the delta and the resulting salinities which occurred during recent years. For this purpose, graphs of actual stream flow into the delta and of mean tidal cycle surface zone salinity at Antioch (estimated from the actual records of salinity for samples taken in the surface zone usually after high tide), for the years 1920, 1924, VARIATION AND CONTROL OF SALINITY 227 PLATE LXXIX >^ NOTE The stream flow required to pre- vent the further advance of any degree of salinity on an_y date is represented by the ordinate under the curve of control flow for that particular degree of salinity .Thus, to prevent the further advance of a salinity of 100 parts of chlorine per 100,000 parts of water on July I5,a stream flow of 6,600 cubic feet per second is required. 76 ^ ro c o o ^g O O +-' Q. MEAN SALINITY AT ANTIOCH _May June July Aug. Sept. Oct. Nov. Dec._ _ 1924 X _ 800 _>^-^ / \ - / / / /l926\ \ - 600 AOO / / \ \ _ 1 1 1 1 1 i I / / 1920 \\ : "" — \ •. \ \ ( \ \ ~ - / ■ i >-\ - 200 - / / / / 1 / i i /6_92 9 ^ 1 - / 1 i' / / / / r 1 / 1 * / •' / ••■' 1927 1 1 II II <0 o c (U c o o 5 o E ro a> i_ +-• to to lO o 1_ 13 14,000 12,000 10,000 8,000 6,000 4,000 2,000 STREAM FLOW REQUIRED FOR CONTROL OF SALINITY Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. GROSS STREAM FLOW INTO DELTA FOR CONTROL OF SALINITY 0.6 MILES BELLOW ANTIOCH WITH COMPARATIVE STREAM FLOW AND SALINITY RECORDS FOR YEARS 1920-24-26-27 AND'29 228 DIVISION OF WATER RESOURCES ]926, 1927 and 1929, are shown on Plate LXXIX. The hydrographs of stream flow are superimposed with api^ropriate legend on the control curves, making it possible to directly compare the actual stream How that entered the delta with the gross stream flow into the delta required for salinity control. Directly above the hydrograjihs of gross control flow and actual measured inflow are shown the curves of variation of mean salinity at Antioch. Thus in 1924, a maximum mean tidal cycle surface zone salinity of slighth' more than 800 parts of chlorine per 100,000 parts of water was reached about September 15. On the same date the stream flow was about 3200 .second-feet and the required control flow at the same time for 800 parts of salinity, as shown by the curves, is of about the same amount. Thus, the condition was reached of an equality between stream inflow and total requirements of consumption and salinity control at that particular degree of salinity and advance of salinity ceased. Subsequently the flow increased and the salinity gradually retreated. Again in 1926, a maximum mean tidal cycle surface zone salinity of a little less than 750 parts of chlorine per 100,000 parts of water was reached about September 1. On the same date, the stream flow into the delta was about 3500 second-feet or about the same amount which the control curves show as required to prevent further advance of salinity at that degree. Before the maximum salinities were reached in both 1924 and 1926, the stream flow was considerably less than the gross control flow requirements, as-shown by the control curves, and hence salinity continued to advance until the stream flow into the delta was sufficient in amount to take care of the control demands for the particular degree of salinity reached. In 1927, a maximum mean tidal cycle surface zone salinity of about 130 parts of chlorine per 100,- 000 parts of water was reached about September 12. On this same date, the stream flow into the delta was about 6200 second-feet, which is practically the amount shown by the control curves as required to prevent further advance of salinity at that degree. Prior to September 12, and extending back to about July 25, 1927, the stream flow into the delta was insufficient to prevent an increase of salinity to a degree of 130 partii of chlorine per 100,000 parts of water and hence the salinity continued to increase at Antioch until the stream flow Avas sufficient to take care of the gross control demands. The relations in other years are similar. Tliese comparisons of actual records of stream flow and salinity with the estimated gross control flows and the salinities resulting there- from, provide a satisfactory check on the estimated amounts of stream flow required for control of salinity. The relation between stream flow and salinity at the time that maximum salinity is reached during the season, when there is neither advance or retreat occurring, provides the best means of checking tlie essential accuracy of the estimated net control flows derived from the determination of the magnitude of tidal diffusion of salinity resulting from tidal action. It is only at the time of maximum salinity when there is neither advance or retreat and a definite control point is reached that an absolute check can be made. It is evident that these comparisons with the actual records of stream flow and maximum salinity in recent years demonstrates the essential accuracy of the estimates of the gross stream flow recjuired for salinity VARIATION AND CONTROL OF SALINITY 229 control, including the required net control flow as well as the consump- tive demands in the delta. It is also interesting to compare the records of stream flow and salinity with the estimated control floAVS and salinities resulting there- from during the period of advance and retreat of salinity in these several past years. It will be noted in each year that salinity did not start to advance at Antioch until the stream flow into the delta had decreased below the amount which the control curves indicate would be required to prevent the advance of salinity at the lower degrees. In general, the salinity started to increase immediately after the stream flow into the delta reached a rate less than the required amount shown for control at 15 parts of chlorine per 100,000 parts of water. Subse- quently, the salinity- continued to increase to higher degrees as the flow decreased to amounts less than those shown by the control curves as required to prevent further increase of sa]init;s^at these higher degrees. After the maximum salinities of the season were reached and retreat of salinity was in progress, the salinity continued to retreat below a par- ticular degree of salinity when the actual stream flow became greater in magnitude than the control flow into the delta shown by the curves as required for that particular degree. These comparisons further demonstrate the essential accuracy of the control curves. For any particular degree of salinity, there actually would be required a greater rate of flow to effect retreat than to prevent advance of salinity. This was demonstrated by tidal diffusion studies which were carried out in the investigation, covering the period of retreat of salinity in the same manner as those presented in Chapter IV for the period of advance of salinity. These studies were omitted from the report because of the fact that, from the standpoint of control or limi- tation of advance of salinity, it is necessary onlj'" to give consideration to the magnitude of tidal diffusion during advance of salinity. How- ever, the fact that a greater rate of flow is required to effect retreat of salinity is of importance and points to the desirability of always maintaining a flow not less than the required amount for the desired point and degree of control, in order to obtain the most effective utiliza- tion of control flows. As a matter of interest and comparison, control curves for Collins- ville and 0. and A. ferry, prepared similarlj' to those for the adopted point of control below Antioch, are .shown on Plates LXXX and LXXXI, respectively. For the same degree of control; namely, for a mean tidal cycle surface zone salinity of 100 parts of chlorine per 100,000 parts of water, the maximum rates of gross control flow into the delta for Collinsville and 0. and A. ferry amount to 8000 and 10,800 second-feet, respectively, as compared to 7000 second-feet at the pro- posed point of control. The relative magnitude of control flows at other times during the season and for different degrees of salinity are in about the same proportion. It is of value at this point to compare the determinations of gross stream flow for control as shown on Plates LXXIX, LXXX and LXXXI Avith the rates of stream flow into the delta related to maximum salinity as shown on Plate XX. It will be recalled that the average time of occurrence of maximum salinity during the season was about 230 DIVISION OF WATER RESOURCES PLATE LXXX 1000 MEAN SALINITY AT COLLIN SVILLE note: The stream flow required to pre- vent the further advance of any degree of salinity on an_y date is represented by the ordinate under the curve of control flow for that particular degree of salinity . Thus, to prevent the further advance of 'a salinity of 100 parts of ctilorine per 100,000 parts of water on July 15, a stream flow of 7,600 cubic feet per second is required. — rtJ O {- CO a. o o o o a. 0) c 't- o •^ ~; 800 w 0) c s o 6C0 400 4^ ^ +^ to Q. 200 June July Au^. Sept. Oct. Nov. Doc._ rf* " ••*x /.' 192* \ — ' . - / y'^ ' / / t - / /-^'9 6\ % - - / / / / \ - / 1920- -^•■» 1 1 1 .• A 1 1 f\ •' / 1 •I V k \ - 1 1 1 1 U \ y^^l929 \ 1 ' - 1 1 1 > / \ •> \ - 1 V \ ■\ ' - 1 -1 / / 1 / . r^. ^ 1 1 1 V\ « ( / .' A4l927 N ^V^/ s^ ' //.' ^ , \r \ / / : / \ s \ \ \ - y ■■■ .' •. \\\ --1 - ^1 ut l.K-J- ,,J,.1,_ _i 1.. 1 1 .. l\,l ' ik (D 14.000 (C 12.000 t 10,000 SALINITY c o o in 2 o E rtJ (U u +- +- I -o c o o S o E OJ 1^ o i- o 24.000 20,000 16.000 12,000 8P00 4/DOO ~i I I I nrn r~r-i rn i r Jan. I Feb. | Mar. i Apr. | May NOTE The stream flow required to pre- vent the further advance of any decree of salinity on any date is ■ represented by the ordinate under ■ the curve of control flow for that particular degree of salinity. Thus, to prevent the further advance of " a salinity of 100 parts of chlorine • per 100,000 parts of water on July . 15,3 stream flow of 10,400 cubic feet per second is required. MEAN SALINITY AT O.&A.FERRY STREAM FLOW REQUIRED FOR CONTROL OF SALINITY June Jul_y 1 I Aug. 1924^ 1926 / .^ Sept. \ \ .■^ Oct. "T— r Nov. I r Dec. Jan. Feb. Mar. Apr. May June July Ai^g. Sept. Oct. Nov. Dec. GROSS STREAM FLOW INTO DELTA FOR CONTROL OF SALINITY AT 0.8. A. FERRY WITH COMPARATIVE STREAM TLOW AND SALINITY RECORDS FOR YEARS 1920-24-26-27 AND '29 232 DIVISION OF WATER RESOURCES September 1. The eoni}3firative amounts of stream flow into the delta as shown by the curves on Plate XX and bv the control curves for September *1 on Plates LXXTX, LXXX and LXXXI, for various dejrrees of salinity, are shown in the following tabulation: Station Maximum mean tidal cycle surface zone salinity in parts of chlorine per 100,000 parts of water Rate of stream flow into delta in second-feet From plate XX Control flow from plates LXXIX.LXXX and LXXXI Antioch Antioch Antioch Collinsville.-- Collinsville-.. Collinsville... O. & A. Ferry 0. & A. Ferry 0. & A. Ferry 100 150 200 100 150 200 300 350 400 ±6.700 6,000 5,400 ±7,300 6,700 6,000 ±6,600 6.100 5.600 6,600 5,800 5,300 7.600 6,600 6,000 6,500 6,000 5.500 The flows obtained from the curves on Plate XX, while not con- sidered as accurate as those from the control curves on Plates LXXIX, LXXX and LXXXI, nevertheless furnish an additional check on the accuracy of the estimated gross control flows for one particular time of the year. The control curves on Plates LXXIX, LXXX and LXXXI are not only more accurate than the relations of Plate XX, but also have the great advantage of showing the gross flow required for control at any time of the year and for any degree of salinity and especially for smaller degrees of salinity than could be obtained from the available data from which the relations on Plate XX were evolved. Although the analj'ses leading to the determination of the flow required for control of salinity have necessarily been rather involved because of the complexity of the basic factors governing the same, the estimates of control flow are amply supported by the more simple and direct relations of salinity and stream tlow as determined from actual records for the 10-year period, 1920 to 1929. The rate of flow required for control of salinity and the positive effectiveness of control by stream flow do not rest upon theory, but are supported by the observed occur- rence of natural control actually effected by the .stream flow during this past 10-year period. The proposed control of salinity by stream flow offers not only a positive and dependable means of control, but also one that would be feasible of consummation. Supplemental Water Supply for Control of Salinity. Tn order to provide the proposed flow for control of salinity, addi- tional water supplies would be required to supplement the stream flow available as under conditions of the last 10 years or more. The .supple- mental water supply required may be readily ascertained from a com- parison of the available stream flow and required control flow. Esti- mates have been made, based upon the records of stream flow into the delta from 1920 to 1929 and the estimates of gross control flow for the proposed control at Antioch. The gro.ss control flow provides for a net flow of not less than 3300 second-feet in the combined channels of the Sacramento and San Joaquin rivers past Antioch into Suisun Bay VARIATION AND CONTROL OF SALINITY 233 and the variable consumptive demands of the delta as estimated for 1929. This gross control flow is shown by the curve on Plate LXXIX, marked "Stream Flow Required for Control of Salinity to 100 Parts of Chlorine per 100,000 Parts of Water." The amounts of supplemental flow for several years of this period are indicated graphically on this plate, as the difference between the curve of gross control flow for 100 parts and the hydrograph of actual stream inflow for these years. The area between the two curves is a direct measure of the supplemental flow required, and the rate of supplemental flow required on any particular day is measured by the ordinate between the two curves. The amounts of supplemental flow required by months and by seasons, with stream flow as during the past 10 seasons from 1919-1920 to 1928-29, are summarized in Tables 28 and 29. In Table 28, the monthly inflow into the delta and the estimated monthly consumption in the delta are shown in the first and second columns respectively and the third column shows the inflow in excess of consumption which, if positive, would be available for control of salinity at the mouth of the river. The negative quantities in this column indicate an excess of consumption over inflow. The last three columns in the table show the estimated monthly supplemental supply to provide the net flow for control of salinity and also to take care of the shortages in the inflow meeting the consumptive demands in the delta. Separate quantities are shoA\'ii for control of mean tidal cycle surface zone salinity to 100, 50 and 25 parts of chlorine per 100.000 parts of water. The annual summaries presented in Table 29 show the shortages by excess of consumption in the delta over inflow both for the entire year and the maximum month in each year, and the amount of supple- mental flow required for salinity control and shortages between supply and consumptive demands for both the entire year and the maximum month. Separate quantities are shown for control for mean tidal cycle surface zone salinities of 100 and 50 parts of chlorine per 100,000 parts of water. For the proposed degree of control to 100 parts of chlorine per 100.000 parts of water, the maximum amount of supplemental supply would have been required in 1924, the driest year of record up to 1930, with a total of 1,128.000 acre-feet for the year and a maximum monthly amount of 330,000 acre-feet. Of this maximum annual sup- plemental supply in 1924, the shortage by reason of excess of con- sumptive demand over supply in the delta amounts to 277,000 acre-feet, with a maximum monthly sliortage of 127,000 acre-feet. As to total annual supplemental supply required, the year 1920 is next in magnitude. However, the data indicate that the maximum monthly supplemental supply required in 1920 exceeds that of the maximum month in 1924 by 24,000 acre-feet. Likewise in 1920, the annual shortage in the supply meeting the consumptive demands in the delta totals 225,000 acre-feet, with a maximum monthly shortage of 151,000 acre-feet. The minimum total annual supplemental supply would have been required in 1923, amounting to 149,000 acre-feet, with about the same amount in 1927. The requirements in 1922 would not have been much greater. These years of 1922. 1923 find 1927 represent about average stream flow into the delta during the summer months under present conditions of upstream irrigation and storage develop- ments. 234 DIVISION OF WA'PIOll ItESOURCES TABLE 28 MONTHLY SUPPLEMENTAL WATER SUPPLY FOR CONTROL OF SALINITY 0.6 MILES BELOW ANTIOCH AND FOR SHORTAGES BETWEEN AVAILABLE SUPPLY AND CONSUMPTIVE USE IN DELTA H Year and month 1920— June July August September. October 1921— June July. August September. October--. November. 1922— July August September October... 1923— July August September October. . . 1924- April May June July August... September October... November 1925— June July August.-. September October. . . 1926— May June July August... September October.. 1927— July August... September October... 1928— June July August September October... 1929— June July August September. October. .. November. Inflow into delta in acre-feet 1,044,000 130,000 70,000 168,000 510,000 2,360,000 539,000 262,000 275,000 423,000 520,000 974,000 306,000 314,000 551,000 712,000 312,000 405,000 624,000 622,000 350,000 113,000 77,000 106,000 183,000 375,000 789,000 1,422,000 441,000 227,000 334,000 522,000 1,385,000 367.000 144,000 141,000 309,000 462,000 591,000 299,000 388,000 564,000 605,000 293,000 218,000 360,000 488,000 689,000 212,000 196,000 324,000 423,000 434.000 Estimated con.sumption in delta in acrc-fcet 148,000 204,000 221,000 158,000 90,000 148,000 204,000 221,000 158,000 90,000 46,000 204,000 221,000 158,000 90,000 204,000 221,000 158,000 90,000 105,000 155,000 148,000 204,000 221,000 158,000 90,000 46,000 148,000 204,000 221,000 158,000 90,000 155,000 148,000 204,000 221,000 158,000 90,000 204,000 221,000 158,000 90,000 148,000 204,000 221,000 158,000 90,000 148.000 204,000 221,000 158,000 90,000 46,000 Inflow in excess of consumption in acre-feet +896,000 —74,000 —151,000 +10,000 +420,000 +2,212,000 +335,000 +41,000 +117,000 +333,000 +474,000 +770,000 +85,000 +156,000 +461.000 +508,000 +91,000 +247,000 +534,000 +517,000 + 195,000 —35,000 —127,000 —115,000 +25,000 +285,000 +743,000 + 1,274,000 +237,000 +6,000 + 176,000 +432,000 + 1,230,000 +219,000 —60,000 —80,000 + 151,000 +372,000 +387,000 +78,000 +230,000 +474,000 +457,000 +89,000 —3,000 +202,000 +398,000 +541,000 +8,000 —25,000 + 166,000 +333,000 +388,000 Required supplemental supply for salinity control* and for shortage between supply and consumption in delta in acre-feet Control to a mean tidal cycle salinity of 100 parts of chlorine per 100,000 parts of water 8,000 277,000 354,000 186,000 28,000 162,000 79,000 7,000 118,000 64,000 7,000 112,000 30,000 60,000 231,000 330,000 318,000 171,000 18,000 56,000 197,000 48,000 48,000 263,000 283,000 65,000 12,000 125,000 13,000 1.000 114,000 206,000 38,000 195,000 228,000 57,000 Control to a mean tidal cycle salinity of 50 parts of chlorine per 100,000 parts of water 10,000 357,000 434,000 264,000 11,000 48,000 242,000 157,000 3,000 21,000 198,000 118,000 24,000 192,000 78,000 100,000 309,000 410,000 398,000 249.000 38,000 92,000 277,000 100,000 90.000 343.000 363,000 123,000 34,000 205,000 58,000 16,000 194,000 286,000 76,000 3,000 275,000 308,000 108,000 Control to a mean tidal cycle salinity of 25 parts of chlorine per 100,000 parts of water 27,000 443,000 520,000 347,000 31,000 112.000 328,000 240,000 40,000 50,000 284,000 201,000 8,000 60.000 278.000 140,000 5,000 174,000 392,000 496.000 484.000 332,000 95,000 156,000 363,000 181,000 3.000 161,000 429,000 449,000 206.000 14,000 70,000 291,000 127,000 48,000 280,000 372,000 155,000 8,000 6,000 361,000 394,000 191,000 40.000 •The net flows for control of salinity at Antioch to 100. 50 and 25 parts are respectively 3,300, 4,600 and 6,000 second-feet. VARIATION AND CONTROL OF SALINITY 235 TABLE 29 ANNUAL SUPPLEMENTAL WATER SUPPLY FOR CONTROL OF SALINITY 0.6 MILES BELOW ANTIOCH AND FOR SHORTAGES BETWEEN AVAILABLE SUPPLY AND CONSUMPTIVE USE IN DELTA Shortage between supply and consumption in delta in acre-teet Required supplemental supply for salinity control* and for shortage between supply and consumption in delta in acre-feet Year Control to a mean tidal cycle salinity of 100 parts of chlorine per 100,000 parts of water Control to a mean tidal cycle salinity of 50 parts of chlorine per 100,000 parts of water Total annual Maximum monthly Total annual Maximum monthly Total annual Maximum monthly 1920 1921 1922 1923 1924 1925 1926 1927 .-_. 1928 1929 225,000 277,000 140,000 3,000 25,000 151,000 127,000 80,000 3,000 25,000 825,000 269,000 189,000 149,000 1,128,000 301,000 659,000 150,000 359,000 480,000 354,000 162,000 118,000 112,000 330,000 197,000 283,000 125,000 206,000 228.000 1.076,000 450,000 337,000 294,000 1,504,000 469,000 919,000 297,000 572,000 694,000 434,000 242,000 198,000 192,000 410,000 277,000 363,000 205,000 286,000 308,000 Ten year average 67,000 39,000 451,000 212,000 661,000 292,000 *The net Gows for control of salinity at Antioch to second-feet. 100 and 50 parts of are respectively 3,300, and 4,600 The total annual amount of supplemental water supply which would have been required during the period 1920 to 1929 to provide only the net control flow of 3300 second-feet past Antioch varies from a minimum of about 150,000 acre-feet in 1923 and 1927 to a maximum of about 850,000 acre-feet in the exceedingly dry year of 1924, 600,000 acre-feet in 1920 and 519,000 acre-feet in the next driest year of 1926. The average for the 10-year period would have been 384,000 acre-feet. With these supplemental supplies provided during each year of the i)eriod, 1920 to 1929. saline invasion would have been controlled and the increase of salinity at Antioch would have been limited to a maximum degree of mean tidal cycle surface zone salinit}' of 100 parts of chlorine per 100.000 parts of water. Moreover, the water in over 95 per cent of the delta channels, from Emmaton and Jersey upstream, would have been practicall}^ fresh. Assuming in each of these years that no additional water supply had been provided beyond that which actually flowed into the delta until such time as the actual flow was less than tlie required flow for the proposed control at Antioch, and that, thereafter, the required supplemental supi)lies for control had been provided, the salinity would have increased at Antioch and at other points in the same manner as during these previous years until a mean tidal cycle surface zone salinity of 100 ])arts of chlorine per 100,000 parts of water was reached at Antioch; but after having reached this degree, the mean salinity would have increased no farther, either at the control station or at points up and downstream. Works Required for Proposed Control of Salinity by Stream Flow. The proposed plan for control of salinity by stream flow would involve the construction of mountain storage reservoirs in order to provide required water supplies for release during the summer period \ 236 DIVISION OF WATER RESOURCES of low stream flow to supplement the supply of water otherwise avail- able and flowing into the delta. The studies of water supply, yield and demand in the operation of major storage units for both the initial and ultimate developments of the State Water Plan* show that ample supplies could be made available to fully meet the requirements for the proposed control of salinity by stream flow, in addition to the demands of the Great Central Valley, delta and upper San Francisco Bay region. In addition to the storage works which would have to be provided to furnish the supplemental water supplies required, it would be neces- sary also to construct additional channel capacity between the Sacra- mento River and the San Joaquin Delta. As shown in Chapter Til, the present channel capacity provided by the two interconnecting channels of Georgiana and Three ]\Iile sloughs are hardly sufficient to take care of the consumptive demands in the San Joaquin Delta, if all or most of the water supply required were to come from the Sacramento River. The net stream flow past Antioch required for prevention of saline invasion into the delta, under the proposed plan of salinity con- trol, must be distributed in both the Sacramento and San Joaquin River channels, in proportion to the magnitude of tidal diffusion in the two channels. Inasmuch as the tidal basin of the San Joaquin Delta is larger in volume than that in the Sacramento Delta, the amount of tidal flow and the magnitude of tidal diffusion in the loAver San Joaquin River is greater than that in the lower Sacramento River in approxi- mately the same proportion. Tlie tidal diffusion as comi)utod in the lower channels of the delta appertains to the combined channels of the Sacramento and San Joaquin rivers (see Plates LXXIV, LXXV and LXXVI), and has been determined empirically from the records of stream flow and salinity during the i)eriod 1920 to 1929. In all cases in this period, the diftusion quantities for the low degrees of salinity, as computed from the actual records, have been for conditions when there were considerable amounts of stream flow entering the San Joaquin Delta from the San Joaquin River and its tributaries. Ilowevei', these would not be the conditions in future years if, as ai)pears-likely during periods of low flow and maximum demands in the delta, all or mo.st of the water supply for the delta would have to be furnished from the Sacramento River, with little if any supj^ly coming in from the San Joaquin River and its branches, especiall}' with the further increase of storage and irrigation diversions which may be anticipated on the San Joaquin River system. The present connecting channels (see Chai)ter Til) would not give the San Joaquin Delta the portion of the total inflow recjuired. Therefore, it would be necessary to ])rovide additional channel ca])acity from the Sacramento River to San Joaquin Delta, of such magnitude that comi)lete flexibility in the distribution of the inflow would be available to allow the water to flow automatically to the portions of the basin where needed to satisfy the consumptive demands and the demands of salinity control. This required addi- tional channel capacity, for flexible distribution of water supply fur- nished from the Sacramento River to control salinity and supply the ' consumptive demands of the delta, could be combined with the require- • Bulletin No. 25, "Report to Legislature of 1931 on State Water Plan," Division of Water Resources, 1930. Bulletin No. 26, "Sacramento River Basin," Division of Water Resources, 1931. VARIATION AND CONTROL OF SALINITY 237 ment of additional channel capacity for transfer of surplus water from the Sacramento River to the San Joaquin Delta, for exportation to the San Joaquin Valley by the San Joaquin River Pumping System of the proposed State Water Plan. The preliminary i)lans * for additional channel capacity between the Sacramento River and the San Joaquin Delta provide for the con- struction of a new channel from a point on the Sacramento River below Hood, extending along the old natural channel of Snodgrass Slough to a triple connection Avith Georgiana Slough and the north and south forks of the Mokelumne River. These latter channels then would be enlarged to some extent to Central Lauding. From this point the water would flow to the various portions of the San Joaquin Delta where needed. The proposed plan for opening up and enlarging the old natural channel of Snodgrass Slough would be essentially a restora- tion of original natural conditions before reclamation development closed off this natural connecting slough as well as several other smaller connecting channels. "^D Results of Proposed Control of Salinity. It is of particular interest to consider the results which would be obtained from the proposed plan of controlling salinity at the lower end of the delta by stream flow. It has been demonstrated previously that the proposed control at a point below Antioch would provide fresh water of ten parts or less of chlorine per 100,000 parts of water in the channels above Emmaton and Jersey, or in over 95 per cent of the delta. Below the proposed control point, salinity would con- tinue to vary in a similar manner as during the last ten years or more, except that the maximum salinity at points in Suisun Bay would be definitelv limited and the modification of stream flow resulting from the proposed State Water Plan of storage regulation and release for various purposes, including control of salinitj^ would modify to some extent the saline conditions throughout the year. Hence, it is of importance to determine, if possible, the salinity conditions under the proposed plan of control and compare the same with those which actually occurred. In both the initial and ultimate stages of development of the State Water Plan,*t provision has been made in the proposed operation of the storage units to furnish without deficiency water requirements of the Sacramento- San Joaquin Delta, including the full consumptive demands and the required supply for salinity control at the lower end of the delta to give positive ])rotection to the water supplies and the lands and developments within the delta area. For the present study, the effect on salinity conditions of the operation of the initial development is considered to be of chief concern. In the proposed initial plan of development, Kennett Reservoir would be constructed with a storage capacity of 2,940,000 acre-feet, and operated to accom- plish the following purposes: (See Plates I and II.) * Bulletin No. 25, "Report to Legislature of 1931 on State Water Plan," Division of Water Resources, 19 30. Bulletin No. 29. "San Joaquin River Basin," Division of Water Resources, 1931. t Bulletin No. 26, "Sacramento River Basin," Division of Water Resources, 1931. 238 DIVISION' or water resources 1. Floods on the Sacramento River would be controlled to 125,000 second-feet nuixiniuni tlow at Red liliift' exceeded once in four- teen ycai's on llie avei'age. 2. A navijiable depth on the Sacramento River of five to six feet would be maintained from tlu^ city of Sacramento to Chico Landinji" with a substantial increase in depths from this latter l)oint to Red Blutf. ;>. Irrigation demands on the Sacramento River above Sacramento would be sui)plied, without deficiency, up to 6000 second-feet maximum draft in July. 4. An irrifi'ation supi)ly without deficiency would be furnished the Sacramento-San Joacpiin Delta for its present requirements. 5. A fresh-water flow would be furnished of not less than 3300 second-feet past Antioch into Snisun Bay, controlling? salinity to the lower end of the Sacramento-San Joaquin Delta. (^. A water supply without deficiency would be made available in the delta for the developed industrial and agricultural areas along the south shore of Snisun, Bay in Contra Costa County. 7. An irrigation sui)])ly without deficiency, would be made avail- able in the Sacramento-San Joacpiin Delta sufficient in amount to fully sujjply the "cropped lands" now being served from the San Joaquin River above the mouth of the Merced River. This would be conveyed to these lands by the San Joaquin River Pum])ing System and would make possible the exportation of all the available supi)ly in the San Joaquin River at Friant. 8. An annual average of 1,581,100,000 kilowatt hours of hydro- electric energy would be generated incidental to other nses. Under this proposed method of operation, the resulting modified stream flow both into the delta and into Suisun Bay, which would have occurred during the period 1919 to 1929, has been estimated by months. These estimates of modified sti-eam flow have been used for estimating the average monthly salinity which Avould have occurred during the same period at points from the lower end of Suisun Bay to the lower delta. In order to carry out a study of estimated salinity conditions under the proposed control flow and operation of the initial development of Kennett Reservoir, it was necessary first to obtain a relation between average monthl^y salinity and average monthly stream flow, based upon the actual records of salinity and stream flow for the i)eriod 1920 to 1929. This special analysis was nuule for four typical stations in the area between the lower end of Suisun Bay and the lower end of the delta, including Bulls Head Point, Bay Point, (). and A. ferry and Antioch. Curves showing the rehition between average monthly stream flow and average monthly salinity were i)lotted from the data for each year of available record at each of these stations, separate curves resulting for the jjcriod of advance and the period of retreat of salinity. For any one year, the two curves provided an empirical relation between avei-age monthly sti-eam flow and salinity covering tli(> eyeh' of variation of salinity during both advance and retreat. VARIATION AND CONTROL OF SALINITY 239 These curves are similar in character to the tidal diffusion curves lieretofore presented, but are substantially different in that the rela- tion between average monthly salinity and stream flow involves the element of time required for salinity to advance or retreat during any particular month, whereas the tidal diffusion curves express an instan- taneous relation between tidal ditt'usion, or net control stream flow, and degree of salinity. The relation established therefore depends upon the variation of stream flow during the month and from month to month in any particular year. For this reason the curves of rela- tion are considerably different in different years of record, depending upon the variation of stream flow. Based upon these curves of empirical relation established from the actual records, estimates have been made of average monthly and maxi- mum seasonal salinity, for the modified stream flow resulting from the initial plan of operation and development of the State Water Plan. The estimated salinities for each year from 1919 to 1929, inclusive, are shown in Table 30. The tabulation summarizes the maximum salinity for the season and the minimum and mean values of average monthly salinitv for each vear. For comparative purposes the table also shows corresponding values of salinity from actual records, and estimated values of salinity actually occurring during years for which no records were available. No records of salinity were available at Antioch and 0. and A. ferry prior to 1920, at Bay Point prior to 1926 and at Bulls Head Point prior to 1924. For these missing years of record, the estimated degrees of salinity which actually occurred were obtained from the curves of relation established from years of record, by applying the actual stream flow. These estimates of salinity which actually occurred were made for all four stations for the years 1912 to 1919, and also for the years 1920 to 1925 for Bay Point and 1920 to 1923 for Bulls Head Point. An entirely independent analysis was made also to check these estimates of salinity which actually occurred, based upon a relation established between mean monthly salinity and the water barge travel of the California and Hawaiian Sugar Refining Corporation (see Plate IV). Using the barge travel and the actual records of related salinity avail- able during the last ten years, a relation was established between the distance in miles that the barge traveled above Crockett, averaged over a month, and the corresponding average monthly salinities at points downstream. This relation was then applied to the average monthly barge travel during the years of missing salinity records. The results of this independent method of analysis checked the previous method of analysis within reasonable limits. There were also a fcAV scattered records of salinity at various points in the Suisun Bay area during the period of missing records, which provided some further check of the estimated values of actual salinity. In all cases the records of salinity checked the estimated values within reasonable limits. As a result of these independent checks on the primary basis of estimating mean salinity for both actual and modified stream flow, it is believed that the estimates presented in Table 30 may be considered to be a close approxi- mation. \ 240 DIVISION OP WATER RESOURCES TABLE 30 COMPARISON OF SALINITY UNDER PROPOSED PLAN OF SALINITY CONTROL WITH ACTUAL SALINITY AND WITH SALINITY UNDER NATURAL STREAM FLOW Mean tidal cycle surface zone salinity in parts of chlorine per 100,000 parts of water Station and year 1912. 1913. 1914. 1915. 1916. 1917. 1918. 1919. 1920. 1921. 1922. 1923. 1924. 1925. 1926. 1927. 1928. 1929. Antioch 0. and A. Ferry 1912. 1913 1914 1915..- 1916 1917 1918 1919. - 1920 1921 1922 1923 1924 1925 1926... 1927 1928 1929 1912. 1913. 1914. 1915. 1916. 1917. 1918. 1919. 1920. 1921. 1922. 1923. 1924. 1925. 1926. 1927. 1928. 1929. Bay Point Estiira'eJ salinity with modiBed stream flow> Maximum for season 100 100 80 80 100 100 100 100 80 100 100 280 280 260 260 280 280 280 280 260 280 280 700 700 680 680 700 700 700 700 680 700 700 Minimum average monthly to 10 Oto 10 to 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 40 Oto 10 to 10 Oto 10 Oto 10 30 30 50 10 10 50 210 30 40 Oto 10 Oto 10 170 Mean of average monthly 20 20 10 10 15 40 20 30 10 25 X 85 85 65 60 75 140 80 "95 60 100 X 300 280 230 200 280 440 280 320 210 300 X Actual salinity' Maximum for season •30 •50 *50 •60 •60 •60 •190 •220 592 185 194 116 815 180 731 130 319 425 •130 •200 •170 •170 •170 •ICO •400 •520 834 454 435 417 1,146 444 915 403 587 700 •450 •600 •500 •500 •520 •550 •800 •900 •1,200 •850 •800 •750 •1.350 •800 1,320 830 910 980 Minimum average monthly •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 •0 to 10 Oto 10 Oto 10 Oto 10 Oto 10 20 Oto 10 to 10 Oto 10 Oto 10 10 •80 •60 •0 to 10 •0 to 10 •0 to 10 •30 •40 •0 to 10 •30 •10 •0 to 10 •60 •170 •0 to 10 20 10 10 100 Mean of average monthly •0 to 10 •10 •10 •10 •10 •15 •40 •50 109 24 22 19 246 38 152 21 62 97 •40 •60 •40 •40 •35 •50 •100 •150 182 115 87 92 423 111 272 87 138 218 •220 •240 •150 •150 •140 •210 •300 •330 •390 •270 •230 •280 •680 •320 486 236 388 484 Estimated salinity with natural stream flow' Maximum for season 10 30 20 20 10 40 80 100 140 80 90 40 400 40 160 40 120 180 90 150 140 100 100 150 270 300 420 250 250 170 650 160 400 160 350 180 350 480 480 400 350 500 680 700 800 650 650 500 900 500 800 500 700 850 Minimum average monthly Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 20 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 30 Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 40 20 40 Oto 10 Oto 10 20 140 Oto 10 10 Oto 10 Oto 10 80 Mean of average monthly Oto 10 Oto 10 Oto 10 Oto 10 Oto 10 10 10 20 20 20 15 10 65 10 25 10 30 X 35 40 35 30 30 50 75 90 no 70 40 60 190 55 85 40 100 X 150 170 160 130 110 200 280 290 300 220 220 200 450 200 270 140 280 X ' The modifled stream is that resulting from the operation of the initial development of the State Water Plan, with Kennett Reservoir (capacity 2,940,000 acre-feet) operated for various purposes, including the proposed control of salinity to the lower end of the delta near Antioch. » Based upon actual records of salinity and estimates of salinity which actually occurred with stream flow during the period of record. > Natural stream flow, based on estimates presented in Chapter III, which would have occurred if upstream irrigation and water .supply developments were not in operation. X Insufficient data for estimating salinity. * Estimated. VARIATION AND CONTROL OF SALINITY 241 TABLE 30— Continued COMPARISON OF SALINITY UNDER PROPOSED PLAN OF SALINITY CONTROL WITH ACTUAL SALINITY AND WITH SALINITY UNDER NATURAL STREAM FLOW Mean tidal cycle surface zone salinity in parts of chlorine per 100,000 parts of water Estimated salinity with modified stream flow' Actual salinity 2 Estimated salinity with natural stream flow* Station and year Maximum for season Minimum average monthly Mean of average monthly Maximum for season Minimum average monthly Mean of average monthly Maximum for season Minimum average monthly Mean of average monthly Bulls Head Point 1912 •800 ♦900 •850 •800 •800 •900 •1,100 •1,200 •1,650 •1,200 •1,050 •1,000 1,590 1,090 1,540 1,020 1,110 1,170 •280 •200 •0 to 10 •20 •50 •130 •150 •130 •100 •50 •50 •200 300 100 40 30 40 380 •520 •490 •330 •330 •310 •430 •570 •580 •710 •520 •400 •530 951 529 718 436 615 717 840 900 900 800 800 900 1,000 1,000 1,020 950 900 900 1,100 950 1,000 900 950 1,030 180 170 OtolO OtolO 30 100 140 100 140 70 60 150 450 70 100 40 80 250 480 1913 490 1914 350 1915 330 1916 300 1917 440 1918 530 1919... _.._ 1920 1921 1922 ._- 1923 1924 1925 1926 1927 1928 _... 1929 1,050 1,200 1,050 950 1,050 1,200 1,100 1,200 1,100 1,150 1,150 130 230 90 100 240 640 100 130 •40 70 510 550 640 460 420 560 880 540 620 450 610 X 500 540 410 360 450 740 460 490 350 480 X ' The modified stream flow is that resulting from the operation of the initial development of the State Water Plan, with Kennett Reservoir (capacity 2,940,000 acre-feet) operated for various purposes, including the proposed control of salinity to the lower end of the delta near Antioch. ' Based upon actual records of salinity and estimates of salinity which actually occurred with stream flow during the period of record. ' Natural stream flow, based on estimates presented in Chapter III, which would have occurred if upstream irrigation and water supply developments were not in operation. X Insufficient data for estimating salinity. • Estimated. 16 — 80995 242 DIVISION OF WATER RESOURCES Based upon estimates of reduction in stream flow into the delta for tlie period 1912 to 192!), as ])resente(l in ('liapter III, it is also possible to obtain an approximation of the salinity conditions which would have occurred if natural stream flow unimpaired by upstream irrigation and storage developments had been available in these years. The estimates of salinity under conditions of unimpaired natural stream flow are of considerable value inasmuch as there has been a conflict of opinion expressed in regard to the probable salinity con- ditions in Snisun Bay as they naturally occurred prior to the exten- sive developments of irrigation and storage works on the upper Sacra- mento and San Joaquin River systems. Therefore, although there has been ample evidence previously presented in this report to show that saline water annually invaded Suisun Bay to the lower end of the delta in early years before any upstream developments occurred, the pos- sibility of estimating the salinity under natural stream flow conditions provides a basis for further confirmation. Based upon the estimated amounts of reduction in stream flow combined with the records and estimates of the actual inflow into the delta, estimates have been made of average monthly salinity which would have occurred under con- ditions of unimpaired stream flow into the delta by applying the estimated amounts of uiiim]iaired stream flow. to the relations estab- lished between monthly stream flow and average monthly salinit}^ from records of recent years, as previously described. These estimates of salinity with natural stream flow are tabulated in Table 30, and afford an opi)ortunity of directly comparing estimated salinity under natural stream flow conditions with the observed and estimated salinity which actually occurred, and also with predicted salinity which would have resulted from the proposed control of salinity by stream flow under the proposed plan of control and operation with the initial development of Kennett Reservoir. The comparative values of predicted and actual salinity shown in Table 30 indicate that salinity conditions for Suisun Bay and the lower delta would have been substantially improved under the proposed plan of control as compared to those actually occurring during the ten-year period, 1919 to 1929. The maximum and average salinity would have been substantially reduced, especially in the upper part of Suisun Bay above Bay Point. Conditions at the lower end of Suisun Bay near Bulls Head Point would not have been materially changed, although the estimates indicate that some reduction of average annual salinity would have been effected under the modified regimen of stream flow, and the maximum salinity would have been reduced in certain years. On the other hand the minimum values of average monthly salinity near Bulls Head Point would have been increased to some extent in certain years due to the effect of storage regulation involved in the projiosed operation of Kennett Reservoir. At i)oints in the upper part of Suisun Bay above Bay Point, the minimum degrees of salinity would have been substantially the same as actually occurred during the period 1919 to 1929. This improvement in the quality of water of Suisun Bay, especially in the upper channels from the lower end of the delta to below Pittsburg, would be of value to the industrial developments along the south side of Sui.sun Bay. Corrosion of cooling water equipment VARIATION AND CONTROL OP SALINITY 243 would be decreased and the present attacks of the teredo on untreated timber piles of industrial water front structures would be prevented or materially reduced. The comparative A^alues of estimated salinity with the modified stream flow under the plan of proposed salinity control and under conditions of unimpaired natural stream flow are also significant. The estimates indicate that, with the modified flow resulting from the proposed operation of Kennett Reservoir under the initial development of the State Water Plan, salinity conditions in Suisun Bay would have been practically equivalent to those which would have prevailed if the stream flow naturally available had been allowed to flow unimpaired into the delta and Suisun Bay. In dry years, such as 1920, 1924 and 1926, and even in such years as 1928 and 1929, the maximum salinities at Antioch and 0. and A. ferry would have been considerably less with the modified stream flow providing for proposed salinity control than with natural stream flow available, and hence salinity conditions would have been even better than under natural stream flow in some years. Summarizing the foregoing studies, the proposed control of salin- ity by stream flow at the lower end of the delta coupled with the furnishing of required water supplies to meet the full consumptive demands of the delta would result in the following accomplishments: 1. The delta would be fully protected from any harmful saline invasion and the present salinity menace removed. 2. Ample and dependable irrigation supplies would be assured for the entire delta. 3. Land values in the delta would tend to be increased and the future possibility of expensive water right litigation between the delta and upstream water users would be eliminated. 4. The water in the channels of over 95 per cent of the delta would be fresh enough for industrial and domestic use. This would provide a suitable source of dependable fresh-water sup- plies for industrial, domestic, municipal and agricultural pur- poses in the upper bay region. Water supplies now or hereafter made available in the delta channels for these purposes could be feasibly conveyed by conduits. 5. The salinity of the waters in Suisun Baj^ would be reduced below that prevailing during the past ten years or more and would tend to approach the equivalent of conditions which would have occurred in the same years with natural stream flow unimpaired by upstream irrigation and storage diversions. The reduced salinity would benefit the industrial interests, especially in the upper Suisun Bay area, by decreasing corrosion and depreciation costs of cooling and condensing water equip- ment and by preventing or materially reducing the present destructive action of the teredo on untreated timber piling in water front structures. Therefore, the proposed plan of controlling salinity by stream flow offers an effective remedy which, if adopted, and applied, would ade- quately take care of the salinity problem of the delta and upper bay region. I APPENDIX A FIELD METHODS AND PROCEDURE IN SALINITY INVESTIGATION FIELD METHODS AND PROCEDURE IN SALINITY INVESTIGATION The program initiated in 1929 for the investigation of salinity in the Sacramento-San Joaquin Delta and upper San Francisco Bay was by far the most comprehensive and intensive in its scope of any undertaken in the previous years of salinity investigation by the State. Although much of the field work undertaken was conducted under methods and procedure similar to those used in previous years, the greatly increased magnitude and scope of the 1929 program of field investigation necessitated a perfection of organization, procedure and methods. Many original and novel methods were developed as the Avork proceeded. This appendix briefly describes the detailed procedure and methods emploved in the field for the investigation of salinity in 1929. Organization The program carried out in 1929 required a much larger field organization than in any previous year. The organization of crews was effected and active work started immediately after the adoption of a program on May 20, 1929. During the course of the work from six to twenty-five men were employed directly in the field. These were grouped in various ways to meet the demands of the different special surveys and operations. Some of the special surveys required as many as twelve to fifteen men to a crew. Because of the large area to be covered, one of the most important necessities was efficient and adequate transportation. Crews were transported by automobile as far as pos- sible, but much of the work required water transportation which was provided by special motor boats, and row boats or skiffs equipped with out-board motors. ]\Iuch of the work on water had to be done at night under unfavorable weather conditions and with rough water, which at times made the work not only difficult but hazardous. Interference from passing commercial and pleasure craft and fishing boats and nets at times added to the difficulties. Salinity Sampling at Regular Observation Stations ' The sampling at the regular observation stations comprised a continuation of the program, but greatly enlarged, under which the variation of salinity had been observed at .stations in the delta and upper bay for several years. The number of stations was increased greatly over previous years, 76 being maintained during most of the season. As the salinity gradually retreated from the delta in the latter part of the season, the number was reduced correspondingly. However, about eighteen stations were continuously maintained throughout the year, wherea.s, previously, such all-year stations Avere onh^ seven in number. ( 247 ) 248 DIVISION OF WATER RESOURCES Samples of water were taken by the local observers at all of these ref^ular stations at four-day intervals about one and one-half hours after the predicted time for high tide and immediately below the water surface, designated as the surface zone. Jn order that the four-day intervals should be the same at all stations, definite arrangements were made for the sampling to be done after the high tides originating at the Golden Gate on the 2d, 6th, 10th, 14th, 18th, 22d, 26th and 30th of each month. Each observer was furnished with a schedule showing the exact time at which samples were to be taken. These schedules were prepared from the published tide tables of the II. S. Coast and Geodetic Survey for San Francisco Bay (at the Golden Gate) and data, previously collected but corrected later during the season, which furnished the average time allowance for travel of the high tide from the Golden Gate to each station. The times for sampling after both the high-high and low-high tides were given in the schedule but the observer was instructed to sample only after the high-high tide when possible. If not possible, or impracticable, the observer was instructed to sample after the loM'^-high tide. At twenty-two stations, samples were taken after both high-high and low-high tide for a period of four months, and at AntiocK, samples after both these tides were taken throughout the 1929 season. During periods of variable stream flow such as occurred in June and December, 1929, daily samples were taken at many of the stations. The samples were taken by means of a weighted bottle and, to insure that there would be no carry-over of salt from a previous sampling, the observers were instructed to thoroughly rinse the bottle with the water in the channel ju.st previous to sampling. Water from the sampling bottle was poured into a two-ounce mailing bottle. The observer filled in upon a sticker previously affixed to the mailing bottle at the laboratory the name of the station, the date, the actual time of sampling (something may have interfered with sampling at the sched- uled time), and the tide, whether high-high or low-high. The two- ounce bottle was mailed in an individual cardboard and tin con- tainer, previously stamped and addressed, to the testing laboratory of the State Division of Highways at Sacramento, where the samples were analyzed. Upon completion of tlie analyses, the empty two-ounce bottles and mailing containers in cartons of fifteen were mailed by the laboratoiy to the observers. The form used for reporting the results of the laboratory analyses is illustrated by the accompanying reduction shown in Figure 1. These forms were in quadruplet of standard letter size. VARIATION AND CONTROL OP SALINITY 249 Form 128 SHEET 1 OF 3 State of California Department of Public Works Division of Watkr Resources Sacramento-San Joaquin Water Supervisor Salinity Investigation in Delta of Sacramento and San Joaquin Rivers Daily Laboratory Report of Analysis of Chlorine Content in Water AT OBSERVATION STATIONS Sample taken one foot below water surface and approximately U hours after high tide by local observers .19. (Month) (Day) High High Tide Low High Tide STATIONS Date Time of Sample Parts of Chlo- rine per 100,- 000 Parts Water Date Time of Sample Parts of Chlo- rine per 100,- 000 Parts Water Remarks San Francisco — ^San Pablo & Suisun Bay: Point Orient Point Davis Bulls Head Point Bay Point 0. and A. Ferry Innisfail Ferry North San Pablo Bay: 1 Sonoma Creek Bridge Grand View Vallejo Cuttings Wharf Napa Petaluma Sacramento River Delta: ColUnsville Mayberry Emmaton Three Mile Slough Bridge 1 Rio Vista Bridge Junction Point ! Liberty Ferry Isleton Ferry Isleton Bridge Howard Ferry Sutter Slough E. D. 2068 Little Holland Ferry Walnut Grove 1 1 1 Figure 1 250 DIVISION OF WATER RESOURCES Tidal Cycle Salinity Surveys Tliis work involved the takinj? of samples at hourly intervals throuofhout a complete tidal cycle of about twenty-five hours and at vertical depth intervals of five or ten feet, depending? on depth of water. It was always the endeavor to obtain at least four samplas in the vertical including one in the surface zone (one-foot depth) and one two feet from the bottom. As the results were to be used to determine the increase and decrease of the salinity with the rise and fall of the tide at the station selected, it was necessary to choose a point in the channel where there would be an unimpaired flow througliout the tidal cycle and where the depth would be representative of the average maximum depth. In some instances a wharf or a structure was found that provided a suitable sampling station. If no Avharf or structure could be found, it was necessary to work from a boat. At stations where it was anticipated that more than one series of samples would be taken, a permanent staff gage was set, and in some instances this gage was referred to a standard datum. At temporary stations a gage was set to an arbitrary datum and removed when the samples had been taken. In order that the set of vertical samples should be truly representa- tive of the variation of salinity in the vertical, it Avas necessary that there should be no delaj^ between the taking of the samples. Various methods of sampling were considered and discarded because of requiring too much time, affording too great an opjiortunity for error under adverse field conditions, or other good reasons. In the first category were weighted bottles or containers and in the next, electrical indicating apparatus. It was considered highly desirable that a sample bottle of water be taken at the proper time and depth, thus insuring a semi- permanent field record and providing a sample which could be analyzed and checked at leisure under the best of conditions. After trying out various methods, it was decided that some means of pumping a sample of water from the proper depth would overcome the objections outlined and would Ibest answer the requirements. Extreme portability was desii-ed and necessary if the work was to be pro])erly completed at all of the locations selected for this special type of survey. It was considered that the apparatus constructed would be more or less standard for other types of special salinity sur- veys. Equi])ment was assembled as follows : A bucket-spray pump was converted by removing the screen and foot piece and Avelding in its ])lace a one-half inch tee with the "run" horizontal. To one end of the tee was attached a street ell closed with a pipe plug and, at the other end, a hose adapter was inserted. This completed the pump which had a weight of about 71 pounds. A high-grade one-half inch garden hose was chosen for a combined sounding line and conduit to convey the water from the desired depth. This was attached to the pump by a female coupling and the free end was closed with a one- half inch vertical check valve. This valve was only necessary when the work was from a wharf or other structure at some distance above the water and, in this case, eliminated the necessity for frequent priming of the pump. To permit rapid sampling even after dark, the VARIATION AND CONTROL OF SALINITY 251 hose was graduated by using hose clamps as markers with one clamp at the ten-foot mark, two clamps at the twenty-foot mark, and, similarly, additional clamps for greater dei)tlis. Heavy cord was wrapped at the intervening five-foot marks. This permitted the operator to determine the soundings in the dark by feeling the graduations. In most instances a standard fifteen-pound current meter weight was found sufficient to hold the hose sufficiently perpendicular for all practical purposes when sampling. This weight was fastened so that the bottom was just two feet from the end of the hose, thereby avoiding the possibility of the end of the hose touching bottom and pumping up mud. The capacity of fifty feet of one-half inch hose is about one-half gallon. Therefore, to insure a complete flushing of the apparatus, a gallon of water was pumped before taking each sample. When depths necessitated using two lengths of hose, double the amount was pumped. This apparatus was used very successfully in Avater with a depth of eighty-six feet and a velocity of about six feet per second. However, with such high velocities, it was necessary to use a graduated stay line, manipulated bj' an extra man, to maintain the hose in a vertical position. The containers used for water samples were the standard two- ounce sample bottles. They were ]iacked in a box made from standard box shook and holding about 180 bottles. This number Avas found sufficient for the average set of samples. The bottles were labeled in advance with a printed sticker for filling in the following data : Name of station, date, test no. and depth. To avoid the possibility of mixing the sample bottles, the men were not permitted to mark the labels in advance on a greater number of bottles than would be used immedi- ately for a group of test samples. A report form in quadruplet (standard letter size) was kept in the field and when the survey was finished it was put in the box with the samples to be taken to the laboratory. This form is shown reduced in size in Figure 2. The field men were required to fill in the blank spaces in the heading, test number (for each group of samples) and staff gage reading. The standard depth referring to a particular gage height was taken when conditions were favorable, usually at slack water, and furnished a check on the rest of the sampling. When it was necessary to work from a boat, a buoy carrying a lantern was anchored in the channel at a point selected for sampling to mark the location after dark. In some instances, the travel on the river rendered this impossible so that it was necessary to rely to some extent on the judgment of the men to anchor their boat in about the same place for each group of samples. The buoy used was patterned after those used by fishermen to indicate the location of their nets. It was shaped like a small wooden sled and was about two by three feet in size with runners made from 2" x 4" stock. Tliis sled worked satis- factorily except in very rough water when the spray would splash on the lantern and break the globe. The sled was fastened to a suitable anchor for which the weight and length of rope were determined accord- ing to the depth of water and velocity of the current. A length of rope fastened to the sled and kept afloat by a wooden block aided in tying to the buoy and, when maneuvering at night, eliminated the danger of bumping the buoy with the boat. 252 DIVISION OF WATER RESOURCES State of California — Department of Public Works DIVISION OF WATER RESOURCES Sacramento-San Joaquin Water Supervisor Salinity Investigation in Delta of Sacramento and San Joaquin Rivers Laboratory Report of Analysis of Chlorine Content in Water for Period OP TIDAL CYCLE Station. Tidal Cycle Survey No.. .__Date 19 Depth feet at. (At beginning) .gage height Chlorine content for standard sample parts per 100,000 (Sample taken one foot below water surface and at specified time after high tide, approximately 15 hours, in accordance with instruction to local observer at this station. Standard sample for this tidal cycle is at one foot depth for Test ) Test No. Time Gage Heiglit Clilorinc Content in Parts per 100,000 for Depth in Feet . Below Surface of Remarks Surveyed by. T. E. STANTON Materials and Research Engineer By- Chemist Figure 2 At most of the locations for tlie tidal cycle salinity surveys, it was found that two men working in shifts of about six hours each could handle the work very nicely. Tlie ])rocedure would be as follows: Both men would go to the appointed i)lace to get everything in readi- ness, install the staff gage, locate the channel, measure the standard depth, put out the buoy if necessary, and generally make conditions convenient and comfortable for a thirty-hour stay. One man would then leave. The actual .sam]iling 0]Kn-ations were as follows: For convenience each set of samples was usually taken on the hour. Just prior to the hour, the man on shift would read the staff gage, calcu- late the depth, mark the sampling depth on each bottle in the space ])rovided on the label and place the marked bottles in order in a small box provided for this purjiose. Ordinarily this would not take more than a few minutes. He would then go to the sampling place, let the weighted hose to the bottom, thereby checking his depth calculation, and start luimping. While some of the men could pump so uniformly as to be able to estimate a gallon very closely, it was always demanded , VARIATION AND CONTROL OF SALINITY 253 that a gallon container be used and filled to insure the pumping of a gallon, or twice the capacity of the hose, before taking each sample. While pumping, the man would pick up his marked bottle, note Miiether or not it was the correct one, and, after pumping at least a gallon, fill the sample bottle from the pump. The hose would then be lifted successively to the other depths of sampling at five to ten foot intervals from bottom to water surface and the operation repeated at each sampling point. River Cross Section Salinity Surveys In this type of survey the object was to determine the distribution of salinity throughout an entire channel cross section at a given phase of the tide. Nearly all of these surveys were made at or shortly after high-high tide. The work was complicated because of the fact that, in the period when most of this work was required, the high-high tide occurred at night and the water was usually very rough. These surveys were made at two channel cross sections in the delta, one on the San Joaquin River near Antioch and the other on the Sacramento River at a point north of Antioch. The San Joaquin River section was about 2700 feet wide and varied in depth from 15 to 50 feet. The Sacra- mento River channel was about 3500 feet wide and had a uniform depth of about 32 feet. In these channels it was desired to take a set of samples at about ten-foot depth intervals from surface to bottom, about every 200 feet across the section. Samples were to be taken from both cross-sections at the same tide and, since one crew only was avail- able for this work, the time factor was of vital importance. A fast, seaworthy speedboat was necessary to permit the crew to travel from one cross-section to the other with a minimum loss of time. Prior to the beginning of the season's work, sights for range lights were selected at each location to enable the operator of the boat to maintain a course on the section line in the dark. As it was not feasible to buoy the section at 200-foot interval sampling points and too much time would have been consumed in endeavoring to locate the boat by triangulation, dead reckoning was relied upon to locate the sampling points. This was accomplished as follows : The throttle of the speedboat was set at a moderate cruising speed, the quadrant marked, the bow headed into the current and the rudder turned just enough to cause the boat to maintain the course of the section. The elapsed time from shore to shore was measured with a stop watch and the proper allowance for current, wind, and engine speed thus deter- mined. Knowing the number of stops to be made, it Avas then possible to closely determine the proper traveling time between sampling points. Three men were used on these surveys. The sampling equipment was the same as that used on the tidal cycle salinity surveys. In the segregation of work, one man was assigned to man the sounding line (graduated hose) and make the soundings, another to man the pump and fill the bottles after flushing the hose between samples, and a third, usually in charge of the party, was responsible for the operation of the boat and the marking of the labels on the bottles as they were filled. Upon arrival at the cross-section, the first duties were to set the light on the north bank, make the speed test across channel and set the light on south bank. It was usually possible to make the preliminary 254 DIVISION OF WATER RESOURCES run across tlio i-iver in ihc darknoss by the jiiiidanco of a star and some j)()int sillionottod aj>ainst the sky on the soutli bank. With the shore lij^lits set, the men took their ])laces in tlie boat and all equip- ment was put in readiness on the way to the first sampling- point. Arriving liere, the boat was headed into tlie eurrent and held on line, witiiout anchoring, by the motor. The sounding was nuide, the pump man began at once to take the bottom sample and as soon as he com- menced filling the bottle, the hose man hauled up for the next depth sami)le. The alternate i)umi)ing, filling of the bottles and hauling were thus continued until the surface zone sample had been taken. The engine throttle was then advanced to give the same cruising speed as that used on the trial trip, and with the aid of a stop watch, the next sampling point was reached. These operations were continued until the opposite shore was reached. Ordinarily the correct number of stops were made, but at times the drift due to wind could not be calcu- lated and more or less than the desired number of stops would be made. That the sampling points were spaced with sur])rising uni- formity, however, was later shown when the soundings were plotted on actual cross-sections made from accurate soundings. Upon reaching the north shore, there remained only to gather the lights and proceed at full speed to the other section, where the same procedure was repeated. Using those methods, a maximum of 70 samples was taken in 70 minutes. This was elapsed time from the beginning of the first sounding until the last bottle was filled at the opposite shore. Record- ing gages near each of the sections were always inspected ])rior to each surve3^ Each bottle was marked with a label on Avhieli was filled in the name of the cross-section, the date, the station (sampling ])oint) and the depth of sami)le. A special report form in quaduplet (letter size) was filled out in the field and sent with the bottles to the labora- tor^^ This form, reduced, is shown in Figure 3. River Cross-Section Tidal Cycle Salinity and Tidal Velocity Surveys The ])urpose of this type of survey was to establish the relation between the variations of salinitv and tidal velocitv throughout a complete tidal cycle and for an entire river cross-section. The observa- tions were made at each of three stations located at fixed points in the channel on eacli of the river sections previously used for the "River Cross-Section Salinity Surveys." It was considered that three stations on each section would be the maximum that one crew could handle and secure at each station a complete hourly set of velocity readings and Avater samples. In order to anchor buoys in the channel at the stations, it was necessary to obtain permission from the U. S. Light- house Service as both of the sections were on navigable waterways and the placing of new lights in the channel without proper notice would have been confusing to navigators. The buoj^s, made from fifteen-gallon oil drums painted the prescribed colors, red, white and green, were anchored in the channel with half-inch wire rope. A "sled" was fastened to each buoy with a short piece of rope and on the "sled" was placed a lantern. \Yith the lanterns burning in rough Aveather and waves not infrequently breaking over the sled, some dii^culty was experienced due to cracking of the lantern globes. This caused little delay, however, as the power boat used was equipped with an excellent VARIATION AND CONTROL OF SALINITY 255 spotlight with which an unlighted buoy could be readily located. Con- siderable difficulty in locating the buoys probably would have occurred, however, had the three lanterns been extinguished simultaneously. State of California — Department op Public Works DIVISION OF WATER RESOURCES Sacrambnto-San Joaquin Water Supervisor Salinity Investigation in Delta of Sacramento and San Joaquin Rivers Laboratory Report of Analysis of Chlorine Content in Water IN RIVER CROSS SECTIONS SEcrriON Survey No.__Date 19__ Gage Height : iSg^"^_rV'^''"^ °^ Survey : ISg*.".^.'.'-'-". Station From Depth at Station, In Feet Chlorine Content in I'arts Per 100,000 For Depth in Feet Below Surface of Left Bank, In Feet Remarks 1 1 Surveyed at Time of Tidal Cycle Stream Flow Measurements: Georgiana No From to. Three Mile No From to. T. E. STANTON Materials and Research Engineer Surveyed by. By. Chemist Figure 3 Comprising the equipment used were the standard sampling pump, the two-ounce bottles with the same label as that used for the cross- section surveys, and an electric current meter outfit. A staff gage set up at one end of the section was read at the beginning and end of each series of observations. In meeting the requirements in this work for a boat with plenty of room and one which could be maneuvered handily, a regular double-ended fishing launch was rented from a fisherman who was hired to operate the boat throughout the measurements. The crew comprised one man for the sampling hose, one to operate the pump and fill the bottles, one to operate the current meter and keep the notes of this operation, and the boatman, who also rendered other assistance when needed. Ordinarily, the men worked in eight-hour 256 DIVISIOxX OF WATER RESOURCES shifts when tlie work was to extenel over a i)eriod of several days. For one tidal cycle only, however, one crew would generally put in about one-half of the cycle to a shift. At each station in each section at hourly intervals throughout a tidal cycle or longer, measurements of velocity were taken at the same times and depths as those of the water samples. The time of the velocity reading as well as the depth was entered on the current meter sheet. The observations and samples at all three stations could usually be taken in about forty minutes elapsed time. The salinity samples were rei)orted on tlie form shown in P^igure 3. Tidal Cycle Stream Flow Measurements As a part of the 1929 investigation, measurements were made of the flow in the Sacramento River and its brancli channels below Sacra- mento for the purpose of determining the division and distribution of the total flow passing Sacramento. All of these channels are affected by tidal action and required special methods and ])rocedure for meas- urement of flow. The methods and {procedure for this type of meas- urement had been ])revioush^ developed and used in connection with the work of the Sacramento-San Joa(piin water supervisor. In a tidal channel there is no fixed relation between gage height and discharge as the relation is constantly changing Avith the change in slope resulting from the rise or fall of the tide. The flow is not only variable in rate but also may change in direction. It was necessary to resort, therefore, to some method of measurement which would determine the mean or net discharge for a complete tidal cycle period of 24 to 25 hours. This was accomplished by making current meter measurements of the flow in the channel at intervals of about one hour throughout a complete tidal cycle and deriving the mean or net discharge for a tidal cycle grajihically from the results as plotted on cross-section paper. The hourly discharges in cubic feet per second were plotted as ordinates against time a.s abscissae. In cases of reversal in flow, the positive flows downstream and the negative flows upstream were plotted respectively above and below the line of zero flow. A smooth curve was then drawn through the plotted points and the total area, within the limits of the beginning and ending of the tidal cycle and enclosed between the curve an'd the line of zero flow, was measured by ])lanimeter. In cases of reversal in flow, the areas above the line of zero flow, designated as positive for doAvnstream flow, and those below, designated as negative for upstream flow, were plani- metered separately and added algebraically. If this algebraic sum J was positive, the net flow for the tidal cycle would be doAvnstream, ^ while, if negative, it would be upstream. The net or nu^an flow for the tidal cycle was then derived by dividing the total area by the length of the intercept between the ordinates at the beginning and ending of the cycle, and multiplying the resulting figure by a factor determined from the ordinate scale. Because of the rapidly changing gage height and corresponding discharge, it was absolutely essential that each hourly set of current meter readings should be taken with maximum disjiatch. Where the channel was of considerable width, therefore, time did not permit the number of velocity observations across the channel which usual stand- VARIATION AND CONTROL OF SALINITY 257 ard methods of current meter measurements would prescribe. It was necessary that the number of velocity readings be reduced and this was accomplished by the following procedure : An initial set of read- ings was taken across the section in accordance with the usual standard methods; the resulting velocities at each measuring point were then plotted on a graph against distance from a fixed point on one side of the section and a smooth curve drawn through the plotted points; by inspection of this curve, it was then possible to select a smaller number of measuring points where it appeared that the velocities were representative averages for considerable sections of the channel width. The reduced number of measuring points were then used for the hourly current meter velocity readings throughout the tidal cycle. Current meter velocity measurements were taken only at six-tenths depth, as the gain in speed with this method was considered of greater value than the slightly greater accuracy which the use of the two- tenths and eight-tenths depth method would have given. Further expedition was accomplished b}^ eliminating the necessity for soundings before each hourly set of observations. Based upon accurate initial soundings, there was prepared a set of standard six- tenths depths for each measuring point referred to a specific gage read- ing. Just before each set of hourly measurements was started, the gage was read and the six-tenths depths for the ensuing measurements were computed and recorded in advance by applying the proper cor- rection to the "standard" six-tenths depths. Ordinarily the measurements were made from a boat which was fastened to and passed along a cable stretched across the channel on the section. Under these conditions, and using the methods that have been described, the hourly measurement for a channel 600 feet wide and 30 feet deep could be made by an experienced crew in less than fifteen minutes from the first to the last reading. Most of the chan- nels were of smaller width and took less time per measurement. For this type of measurement, the endeavor was to select a straight stretch of channel of more or less uniform depth. This was of par- ticular importance where reversals of current occurred with the flood and ebb tides. If the channel were not fairly uniform under these conditions, the points selected to give average velocity for one direc- tion of flow might not hold when the flow was in the opposite direction. The actual measurements were ordinarily begun about two hours after either a high or a low tide. Hourly measurements were continued for a period of about 25 hours or more, or until the gage indicated the same tidal stage during the similar and next succeeding period of flood and ebb tide as that occurring at the beginning of the measurement. In cases of reversal in flow, the time of slack water was observed as nearly as possible by means of a rod float, and it was the usual practice to avoid making current meter measurements near the time of slack water. In addition to the engineer in charge, the stream-gaging crew for each measuring station usually comprised two men each for three shifts in a twenty-four-hour period. One man would handle the boat and keep notes while the other operated the current meter. At the begin- ning of the measurement, the engineer in charge would aid in making the proper set-up, selecting the measuring points from the initial 17—80995 ^ 258 DIVISION OF WATER RESOURCES soundings and set of standard gagings, and deciding on all details of procedure. Essential items of equipment were : row boat, cable, staff gage, electric current meter (cable suspension), rod float, current meter notes, cross-section paper on small drawing board, light block and tackle with a "come-along," lanterns, and temporary camp equipment. The cable was made up from Stone patent clothes line, about 3/16 inch in diameter. This has a twisted steel core and is galvanized. The cable was graduated by forcing strips of flagging through the strands ; white strips every ten feet and red every fifty feet. It was necessary to arrange the cable suspension so that the cable could be easily and rapidly slacked to the bottom of the channel to permit the passing of boats and steamers. A rod float was used to observe the direction of current for each hourly measurement. Tide Gage Operation In order to obtain complete information on tides in the bay and delta channels, required for determining the effect of tidal action on the variation of salinity, a number of tide gage stations were established at the beginning of the work in 1929 to .supplement those already in operation under Federal, State and private agencies. The following new stations were established : Benicia, Antioch, Collinsville, Sacra- mento and San Joaquin ends of Three-]Mile Slough, Walnut Grove, San Joaquin end of Georgiana Slough, Mossdale Bridge and Sacra- mento. At a later time stations were established at Crockett, Point Orient, Hunters Point, San ]\Iateo Bridge and Dumbarton Bridge. Automatic tide gage recorders were installed at all of these stations, including six "Stevens Type B" recorders equipped with special time and gage height ratios, two "Stierles" recorders, and one standard and several portable-type tide gages borrowed from the U. S. Coast and Geodetic Survey. The maintenance of these new stations and the acquired mainte- nance of a number of those previously in operation by other agencies practically required the full time of one man who was designated to make the continuous rounds of the stations and keep all equipment in first-class working order. Staff readings Avere taken and the recorders checked at frequent intervals in accordance with the standard of the U. S. Coast and Geodetic Survey. In addition to the special man assigned to the maintenance and inspection of all gages, local observers Avere appointed to make daily readings of the staff and clock for a number of the gages. All tide gages were tied to a common level datum by precise level lines. The basic precise level lines were run by the U. .S. Geological Survey in cooperation with the State. From the precise level bench marks thus established, the tide gages were tied in by lines of levels run by the State. This was a most important part of the field work connected with the installation of these tide gages. Summary of Operations The following tabulation summarizes the number of the various types of special surveys made and the number of samples taken and * VARIATION AND CONTROL OP SALINITY 259 analyzed for salinity during the investigation from May to December, 1929 : Type of station or survey Number of stations Number of surveys Number of salinity samples Regular salinity observations Special tidal cycle salinity surveys Special river cross-section salinity surveys Miscellaneous salinity observations Complete chemical analyses Special stream gaging Automatic tide gages Totals 76 14 2 ►12 5 14 90 33 59 182 4,695 9,457 6,317 150 *18 20,637 * Samples taken at four additional stations in January, 1930. (See Table 36.) PLATE LXXXII acramento-San Joaquin Water Supervisor of Chlorine per 100,000 Parts of Water, 1920 I PLATE LXXXn DELTA OF SAN JOAQUIN a SACRAMENTO f^:^/"''-^Kr^- RIVERS ,/-' " j4-':: 'h, >.«;■• " ■' M "■'!-. i»....x;'" RepTodvcetl from 19SI Iti:porf Saerampnto-San Joaqvln Water Supervisor Delta o{ Sacramento 1111] San Joaquin Rivers. Showine Limita of Salinity Encroachment of ]00 Parts of Ctilorine per 100.000 Parta of Water. 1920 > 1931. Inclusive. ^0 ATJ3': r:rr :::.f?''t f'" '""' "*• APPENDIX B LABORATORY METHODS FOR DETERMINATION OF SALINITY LABORATORY METHODS FOR DETERMINATION OF SALINITY Although there are several methods used for determination of salinity in water, it is recognized generally that the most accurate is a chemical analysis. For a determination of all dissolved salts, this involves a complete quantitative and qualitative chemical analysis of the water. However the salinity of ocean water largely consists of common salt (Na CI) and it is common practice to express the salinity of ocean water in terms of its chlorine content. Therefore, since the salinity of the waters of the upper bay and delta is mostly the result of invasion of saline water from the ocean, the salinity has been deter- mined, from the beginning of investigations by the State, in terms of chlorine content. There are three standard methods of chlorine determination. 1. Gravimetric Method. Determination of chlorine combined as chloride by precipita- tion as silver chloride. 2. Volumetric Method. (Volhard.) . Determination of chlorine in acid solution, silver thiocyanate and ferric alum method. 3. Mohr Method. Volumetric determination of chlorine in a neutral solution, silver chromate method. Under the first, or Gravimetric, the chloride ion is precipitated and weighed as silver chloride; under the second, or Volhard 's method, the chloride is precipitated with an excess of silver nitrate, precipitated silver chloride filtered off, and the excess silver nitrate in the filtrate is then titrated with thiocyanate using ferric alum as an indicator; whereas under the third, or Mohr method, the neutral solution is titrated with silver nitrate using potassium chromate as an indicator. While the precipitation and weighing method is very accurate, it requires considerable time and is subject to various possible errors through manipulation when an attempt is made to speed up the work. Volhard 's method is more rapid than the first method, but is subject to the same limitations as to the number of determinations which can be made in a given time. Either the first or second method takes at least ten times as long as a determination by the Mohr method. Adopted Method of Analysis The method adopted and used for the chemical determination of chlorine content of salinity samples is that known as the *'Mohr" method, involving the titration of a neutral solution of the sample of water with silver nitrate, using potassium chromate as an indicator. ( 263 ) 264 DIVISION OF WATER RESOURCES This method can be used only with a nentral solution but, as the water which was being analyzed was seldom acid or alkaline, it was perfectly adapted to the problem. It is standard for analysis of water, is rapid, easily checked, and, while subject to certain errors, attains a high degree of accuracy by standardized procedure. Very few of the waters were alkaline to phenolphthalein but, where such was the case, the sample was neutralized with 1/50 normal acid. The accuracy obtainable with the method used was found to be close. Two experienced chemists could check one another within the limits of the burette, or 0.1 ml. The salinity range of the water analyzed was from one part to about 1900 parts of chlorine per 100,000 parts of water. Inasmuch as, under the method used, two chemists were able to check each other within a frac- tional part of one per cent or within 20 parts of chlorine per 100,000 parts of water when determining the highest concentration, it can be seen readily that the accuracy of the method adopted was amply sufficient for the purpose. 1 Laboratory Procedure The solutions used in the titration of water samples for salinity comprised silver nitrate and potassium chromate. The standard solu- tion of silver nitrate was prepared, in accordance with usual laboratory practice, of such strength that one milliliter (ml.) of the silver nitrate solution would completely react Avith and be equivalent to one milli- gram of chlorine in a standard sodium chloride solution containing one gram of chlorine per liter of sodium chloride solution. The stand- ard silver nitrate solution contained about 4.794 grams (dry weight) per liter of silver nitrate solution, the exact amount depending u])on the purity of the silver nitrate. The standard sodium chloride solution contained 1.6485 grams (dry weight) per liter of sodium chloride solu- tion. The potassium chromate solution, used as a color indicator, was prepared by dissolving 50 grams of potassium chromate in sufficient distilled water to make one liter of solution. The potassium chromate must be free from chlorides. In order to have a standard fon- comparison of color to denote the completion of the titration, a color standard was prepared by adding one milliliter of the potassium chromate solution, as above prej^ared, to 50 milliliters of distilled water and 0.3 milliliters of the standard silver nitrate solution. This color standard was of a reddish orange color due to the ]irespnce of silver chromate resulting from the combination of silver nitrate and potassium chromate. The volume of the color standard was the same as the volume of the diluted samples of water to be analyzed for salinity. The procedure of titration was then as follows : The water sample to be analyzed for salinity was diluted with distilled water to make a total volume of the diluted sample equal to 50 milliliters. The amount of the water sample used was chosen so that about six milliliters of the standard silver nitrate solution would be required to complete the titration. To this diluted sample, one milliliter of the potassium chromate solution was added followed by the addition of the standard silver nitrate solution until the color of the sample matched with the color standard. The amount of standard silver nitrate solution in the color standard, namely 0.3 milliliters, was then subtracted from the I VARIATION AND CONTROL OF SALINITY 265 total amount of silver nitrate solution added to the sample. The remaining number of milliliters of the standard silver nitrate solution used gave the number of milligrams of chlorine in the original quantity of the sample taken for dilution. It was then merely a matter of arithmetic to obtain the number of parts, or grams, of chlorine per 100,000 parts, or cubic centimeters, of the sample. Two permanent set-ups were used, with the light conditions as near the same as it was possible to obtain. Two chemists were employed constantly for the most part in this work and, in order to eliminate the personal error, the personnel was not changed except that additional assistance was furnished from time to time when more samples were received in a shorter period than two men could handle expeditiously. Each man would prepare two sets of samples (about 30 to a set) and titrate one set. The positions would then be changed and the operators would titrate one another's second set. It was required that all samples check wathin 0.1 ml. The entire halogen content of the samples were reported in terms of chlorine ; no separation between them being made. When but a limited number of samples of water were being received at the laboratory daily and it was necessary for a chemist to switch from one .job to another, such as clerical work, making out reports, and shipping sample bottles, chlorine determination of 60 sam- ples was considered a good day's work for one man, not including a check determination. During the early summer months of 1929, water samples for salinity investigation began to arrive in large numbers and it became evident that this would increase during the summer months so that a standard method of procedure would be needed to expedite the reporting of results with no delay. The procedure finally adopted to best meet the conditions was as follows : Samples were handled in box lots as brought to the laboratory in order to complete sets of samples so box lots of clean bottles could be sent out again. All sample boxes contained a tabulated sheet giving time, date, location, and observer. Bottles were counted to check with the number shown and then compared against the list as to location, time and date, to cheek out any discrepancy so that a suitable record could be made. The time, date, and location of each sample was listed in a record book for further reference. Thirty samples were run at one time by placing the bottles in a row, placing a beaker in front of each sample bottle, putting a suitable quantity of the sample in the beaker according to amount of salt present, diluting the sample with distilled water and titrating the same, and finally replacing the beaker in original position on the table so as not to leave any empty spaces in the beaker row in order to keep all samples in correct position. Each man took care of his own glassware. By this method one operator was able to report an average of 120 to 130 analyses per day. Where the operator was required to do all clerical work and care of glassware attached to reporting results, an average of 60 samples was analyzed. Later on when it became apparent that duplicate results would be advisable, the method used was the same except that, instead of placing one beaker in front of the sample bottle, two beakers were placed in 266 DIVISION OF WATER RESOURCES position and two samples of water taken. Duplicate results were obtained by having one operator complete one set and having another operator complete the other set. Results were then compared, and, if not checking within the variation allowed, another set of duplicate determinations were made. By this method of procedure one operator was able to complete an average of 90 samples or 180 determinations per day. The methods of procedure above described apply particularly to the 1929 season, when over 20,000 samples of water were analyzed in a period of eight months. However, the methods of analysis used were the same in previous years from 1923 to 1929, during which period about 10,000 samples were analyzed; and also have been the same since 1929. Complete Chemical Analysis of Water For the more complete chemical analysis of water, the residue (total solids) was determined by weighing after evaporation of sample at 110° C. A qualitative and quantitive analysis was then made to determine carbonates, bicarbonates, silicates, iron and alumina, calcium, magnesium, sodium, chlorides, and sulphates. The total hardness was obtained from the magnesia lime content by the following formula : *Hardness (H) = Ca X 2.5 + Mg X 4.1. The alkalis, as Na, were calculated as follows : *Na= .83 CO3 + .41 HCO3 + .71 CI. + .52 SO,—. 5 H (hardness) Other constants were obtained by standard practice for water analysis. • U. S. Geological Survey Water Supply Paper 495, 1923, page 95, 96. APPENDIX C RECORDS OF SALINITY OBSERVATIONS Table Page 31 Description of salinity observation stations, 1920 to 1931 268 32 Period of record of salinity observation stations, 1920 to 1931 --- 272 33 Salinity observations, Sacramento-San Joaquin Delta and upper San Francisco Bay, 192D to 1931 274 34 Miscellaneous salinity observations, prior to 1920 377 35 Miscellaneous salinity oheervations, after 1920 386 36 Summary of complete chemical analyses of water at points in San Francisco Bay and Sacramento and San Joaquin River channels.-- - Following 392 268 DIVISION OF WATER RESOURCES TABLE 31 DESCRIPTION OF SALINITY OBSERVATION STATIONS, 1920 TO 1931 Station San Francisco, San Pablo and Suisun Bays Point Orient -- Point Davis --- Carquinez Light Station. Crockett Bulls Head Point ' Bay Point Sprig Club 0. and A. Ferry Miles* from Golden Gate Innbfail Ferry- Pittsburg 0. and A. Bridge. North of San Pablo Bay Grand View Sonoma Creek Bridge. Vallejo Lakeville. McGill... Cuttings Wharf. Merazo Napa Petaluma. Sacramento River Delta Collinsville Mayberry Mayberry prior to October, 1929 and in 1931 ,-- Emnaaton. Three Mile Slough Bridge. Three Mile Slough Ferry.. Rio Vista Bridge.. Junction Point Ryer Island Ferry. Liberty Ferry Grand Island (Steamboat Slough)' - Jones Landing. 12.3 25.2 26.3 27.5 34.0 39.9 44.7 46.5 47.3 50.0 50.6 27.0 26.4 29.1 33.8 30.6 36.7 32.7 43.7 45.7 50.8 54.2 54.9 57.7 60.0 61.2 63.5 65.2 06.5 67.6 68.2 68.2 Time interval between high tide at Golden Gate and time for taking samples at station Hours Minutes 20 15 20 25 50 15 30 40 50 25 20 10 10 35 40 25 00 40 20 30 25 40 40 45 55 00 05 10 20 25 30 30 Location Northerly end San Francisco Bay, east shore, one-half mile south of Point San Pablo, at wharf of Standard Oil Company. Easterly end San Pablo Bay, south shore, Oleum wharf of Union Oil Co. Carquinez Strait, near junction with Mare Island Strait. Carquinez Strait, south bank at wharf of California-Hawaiian Sugar Refining Corp. Westerly end Suisun Bay, south shore, at wharf of Mountain Copper Co. Suisun Bay, south shore. Bay Point wharf of Coos Bay Lumber Co. Montezuma Slough, about 2 miles from Sui- sun Bay end. Upper end Suisun Bay between Mallard Station and Chipps Island on Sacramento- Northern R. R. Ferry crossing. Montezuma Slough, about 1 mile east of junction with Cut-off Slough, near north- erly end of Grizzly Island. South bank of New York Slough, at plant of Great Western Electro Chemical Co. Montezuma Slough, at Sacramento-North- ern Railroad crossing. Petaluma Creek, State Highway drawbridge near town of Grand view. Drawbridge, Sonoma Creek entrance. Sears Point Toll Road bridge, on Napa River, about one mile from Mare Island Navy Yard Causeway. Petaluma Creek, at town of Lakenlle about 7H miles from mouth of creek. Sonoma Creek at McGill on Northwestern Pacific Railroad about 1 mile south of Wingo. Right bank of Napa River, opposite north end of Bull Island, near Carneros Station on Southern Pacific Railroad. Hudemann Slough Bridge, due south of Merazo Station on Santa Rosa branch of Southern Pacific Raihoad. Third Street bridge on Napa River, at Napa . Petaluma Creek, at Washington Street bridge in Petaluma. North bank Sacramento River at junction with San Joaquin River. North bank of Sacramento River just below Mayberry Slough. South bank ot Sacramento River just above Mayberry Slough. South bank Sacramento River on Horseshoe Bend. At junction of slough and Sacramento River. Near junction of Three- and Seven-Mile sloughs. Sacramento River near northerly limits of Rio Vista. Right bank of Sacramento River just below the junction with Steamboat Slough. Lower end of Cache Slough, just above junc- tion with Steamboat Slough. On Cache Slough at junction with Prospect Slough. Steamboat Slough at Grand Island Drainage Pumping Plant, 3 miles from Junction Point. Cache Slough, one-half mile above junction of Cache and Lindsey sloughs. VAEIATION AND CONTROL OF SALINITY 269 TABLE 31— Continued DESCRIPTION OF SALINITY OBSERVATION STATIONS, 1920 TO 1931 Station Miles* from Golden Gate Time interval between liigh tide at Golden Gate and time for taking samples at station Location Hours Minutes Sacramento River Delta —Continued Isleton Bridge ' . 68.7 68.7 69.6 71.4 72.8 73.2 74.4 77.4 77.4 77.6 82.5 90.6 103.5 123.5 54.9 58.0 58.9 61.4 63.5 65.4 71.0 72.0 72.0 72.0 74.6 77.5 79.6 80.6 81.0 82.7 83.0 84.7 85.6 86.1 86.3 6 6 6 6 7 7 7 7 7 7 7 8 9 No 5 6 6 6 6 6 6 8 8 8 8 30 35 40 55 00 05 15 25 25 25 50 25 30 tide 55 05 10 20 25 30 55 00 00 00 15 25 35 40 40 50 50 00 05 10 10 Sacramento River, one mile upstream from Isleton. On Cache Slough, 114 miles above junction with Lindsey Slough. On Steamboat Slough, 4 miles above its junction with Sacramento River. On Steamboat Slough, IH miles below junction with Sutter Slough. At junction with Miner Slough. Back borrow pit of Reclamation District 999, 2 miles above junction with Miner Slough. Sacramento River, right bank at town of Ryde. Sacramento River, one-half mile below upper end of Steamboat Slough. Sacramento River at highway bridge cros- sing river. Cache Slough Wallcer Landing . - . . Howard Ferry . Sutter Slough Little Holland Ferry Ryde Grand Island Bridge * Walout Grove. ... . _ Paintersville Bridge Hood Ferry . . Sacrampnto River one-half mile above Hood. Freeport Ferry' .. -.. . Sacramento River at FreeDort. Sacramento Verona _ road Bridge. Sacramento River iust below Verona. San Joaquin River Delta Antioch San Joaquin River, at City Water Works Pumping Plant. San Joaquin River, 3 miles above Antioch. San Joaquin River, right bank, about tiiree- fourths mile above Antioch Toll bridge. San Joaquin River, left bank, 1 mile below mouth of False River. San Joaquin River, 1 mile above False River Sherman Island Ferry Curtis Landing Jersey.. Blylock Landing* Twitchell Island Pump Webb Point... on Bradford Island. San Joaquin River, 1}^ miles above Three Mile Slough, on Twitchell Island. San Joaquin River, at northeast corner of Webb Tract opposite mouth of Mokel- umne River. False River, 2 miles below Old River Webb Pump Central Landing, Bouldin Island Junction. Mokelumne River, left bank, one-half mile Central Landing, Main Blakes Landing, Venice Island. Quimby Pump .. . . . above San Joaquin River Junction. Mokelumne River, in main channel opposite Central Landing. San Joaquin River, right bank, about two miles above junction with Old River. Sheep Slough at unction with Sand Mound Ward Landing. . Slough and Old River. San Joaquin River near junction with Little Holland Pump Connection Slough on the southwest side of Empire Tract. Rock Slough, north bank, l}4 miles west of Medford Island Pump McDonald Pump Old River junction. South side Medford Island, on channel con- necting Whiskey Slough and Middle River. San Joaquin River, northeast corner of Mandeville Pump McDonald Island, about IH miles below Hog Island. Connection Slough, north bank, 1 mile west Camp 3H, King Island' Zuckerman Pump..... of Middle River, on south end of Mande- ville Island. West side King Island at junction of White Slough and Honkers Cut. Empire Slough, on north side of Lower Jones Rindge Pump Tract, about % mile west of WTiiskey Slough junction. San Joaquin River, north bank, 1 mile below Orwood Bridge Fourteen Mile Slough junction. Old River, at Santa Fe Railroad crossing. Orwood. 270 DIVISION OF WATER RESOURCES TABLE 31— Continued DESCRIPTION OF SALINITY OBSERVATION STATIONS, 1920 TO 1931 Station Miles* from Golden Gate Time interval between high tide at Golden Gate and time for taking samples at station 1 Location Hours Minutes San Joaquin River Delta —Continued Palm Tract 86.3 86.6 86.7 87.7 87.7 88.4 90.1 90.8 92.3 94.2 94.8 101.0 104.8 108.5 109.0 125.8 78.0 78.7 78.8 80.2 81.8 81.9 83.1 83.4 85.8 86.4 87.0 8 8 8 8 8 8 8 8 8 9 9 9 10 10 10 No 7 7 7 7 7 7 7 7 8 8 8 10 15 20 20 20 30 40 45 55 10 IS 55 20 50 55 tide 20 25 25 30 40 40 45 SO 05 05 10 Old River, west bank, near Palm Tract Sing Kee Landing pump, just north of Santa Fe Railroad crossing. White Slough, about 2 miles above junction East Contra Costa Irrigation Dbtricts . with Honker Cut. Indian Slough, at East Contra Costa Irriga- Middle River, Post Office Middle River, Main tion Di.strict pumping plant. Middle River, east bank, at Santa Fe Rail- road crossing. Middle River, center of main channel, at Mansion House - Santa Fe Railroad crossing. Old River, east bank, at junction with North Walicfield Landing Victoria Canal. San Joaquin River, left bank, just down- Stocliton Country Club Drexler Bridge stream from lower mouth of Burns .Cut- off. On Lindley Cut-off (San Joaquin River), north bank, about % mile above Burns Cut-off junction. Middle River, at southwest corner of Drex- Clifton Court Ferry - ler Tract, at Borden Highway bridge. Old River just below junction with Grant Stockton Line Canal. Near head of Stockton Channel at wharf of Williams Bridge California Transportation Company. Middle River, about 4 miles below Salmon Whitehall Slough junction. Old River, west of junction of Salmon Slough Mossdale Highway Bridge" — Western Pacific Railroad Bridge Durham Ferry Bridge Mokelumne River Delta Camp 2, Tyler Island -- and Paradise Out, due north of Tracy. San Joaquin River at Lincoln Highway crossing, about 3 miles southwest of Lathrop. San Joaquin River, about one-half mile up- stream from Massdale Bridge. San Joaquin River, one-half inile below San Joaquin City. At junction of North and South Forks of Camp 35, Staten Island Southwest Point, Staten Island. Camp 33, Staten Island Camp 7, Staten Island -.. Tyler Island Ferry '» Camp 11, Staten Island" Camp 29, Staten Island" Eagle Tree Mokelumne River. South Fork Mokelumne River, north bank, 1 mile above junction with North Fork. North Fork Mokelumne River, south bank, just above junction with South Fork. South Fork Mokelumne River, north bank, 2 miles above North Fork junction. North Fork Mokelumne River, south bank, approximately 3 miles above South Fork junction. Georgiana Slough, about due east of Isleton. North Fork Mokelumne River, east bank, 4 miles above South Fork junction. South Fork Mokelumne River, north bank, opposite Terminous. North Fork Mokelumne River, south bank Camp 25, Staten Island - - Camp 24, Staten Island IJi miles below Miller's Ferry Bridge. South Fork Mokelumne River, west bank, 1 mile above Sycamore Slough Junction. South Fork of Mokelumne River, one-half mile below junction with Hog Slough. VARIATION AND CONTROL OF SALINITY 271 TABLE 31 —Continued DESCRIPTION OF SALINITY OBSERVATION STATIONS, 1920 TO 1931 Station Miles* from Golden Gate Time interval between high tide at Golden Gate and time for taking samples at station Location Hours Minutes Mokelumne River Delta — Continued New Hope Bridge.- . 87.0 88.9 61.4 68.2 78.7 82.7 82.9 83.0 83.1 8 8 10 30 North end Staten Island near upper junction Camp 20, Staten Island Drainage Water Stations Jersey Drain North and South Forks Mokelumne River South Fork Mokelumne River, west bank, one-half mile below Beaver Slough Junc- tion. Jersey Island drainage pump on San Joaquin Grand Island Drain, Steam- boat Slouch River, about 1 mile below False River. Grand Island drainage pump on Steamboat Camp 35, Staten Island Drain. Slough, about 3 miles from Junction Point. Staten Island drainage pump on South Fork Mokelumne River, 1 mile from junction with North Fork Mokelumne River. McDonald Island drainage pump on San Joaquin River, about 1}^ miles below Hog Island. Bacon Island drainage pump on Old River, Mandeville Drain near junction with Rock Slough. Mandeville Island drainage pump on Con- Camp 11, Staten Island Drain. nection Slough, about 1 mile from Middle River. Staten Island drainage pump on North Fork Mokelumne River, 4 miles above junction with South Fork Mokelumne River. * Mileage from Golden Gate to observation stations is measured along the main channel. For observation stations off the main channel, the mileage shown is the distance along the main channel to a point thereon where the time of occur- curence of tidal phases is the same as that at the observation station. (See Plate III for map showing location of obser- vation stations.) > This station is practically in the same location as .^rmy Point. Salinity records in Tables 33 and 35 at this location for the years 1924, 1925 and January to March, 1926, are shown under the station designation "Army Point Site." 2 Called Island Home in 1920. 3 Observations during 1920 at Isleton Ferry. ' Bridge removed in 1925. Salinity records in 1924 only. ■'■ Salinitv observations at Freeport Bridge beginning in 1930. <■• Observations at this station taken only from September 13 to 19, 1919. (See Table 34 for record of observations.) ' Observations in 1931 at King Island Pump. ' Called East Contra Costa Irrigation Company prior to organization of District in 1926. » .^Iso called Lincoln Highway Bridge and Mossdale Bridge. '« Not properly in Mokelumne River Delta, but on Georgiana Slough between Sacramento and Mokelumne rivers. " Called North Fork Pump in 1920. '= Also called Terminous in 1920. I TABLE 32 PERIOD OF RECORD OF SALINITY OBSERVATION STATIONS, 1920 TO 1931 Station 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 San Francisco, San Pablo and Suisun Baya Feb. 10-Deo. 30 Feb. 6-Dec. 30 Jan. 2-Deo. 30 Jan. 2-Deo. 30 Jan. 2-Db Bridge removed in 1925. ' Salinity observations at Freeport Bridge beainning in 1930. ' Observations in 1920 originally recorded under the station designation "Venice." * Obeervations during 1931 at Kin^ Island pump. • Called East Contra Costa Imgution Company prior tc organiiation of District in 1926. " Also called Lincoln Highway Bridge and Moadale Bridge. I ' Not properly in Mokelumne River Delta, but on Georgians Slough between Sacramento and Molflumne rivers. " Called North Fork pump in 1920. ■■ Abo called Terminous in 1920. 1095 — page 273 18—80995 274 DIVISION OF WATER RESOURCES an < 00 3 O J= O v2 3 C c u G. E I/) ooo OO OO .00 O -^ CO ^ CO o OO ' C^ r^O »ft (MtO -^ — .CO v4 • * ■ «fd iCCOCI iO<0 1 • U^C^Cl ' eo o CO ii rt 1^ t^co^ O** ■ CO i . r* CO 00 J- CO I • »-4 » t < QCO • •toco C4 • 1 •« t^'* • cc^ t^U5 I CI ■ •<«•*-< coco • 1 >co*n Sfi • ""fCO Cfl 1 'H O ' . '• c o 1 j: Q . o coco CO ^ lO .NoS « 'o -^ lOCO ^ h. a c O eo ■OUO ICO o • Ob c^ ^ • >^ ■^ *S "S (» OOC c ooo i 1 ■*»« '^ • OiO « ooo I»o OOOOM Cv CTJ « -^r . . -♦- • o»coi .o> o -^ ^Ol •* -"r iM 1 1 » ^ oaos « • II w^ • OO -TP -^ iC »c »c r— r-co U30 •♦— * « • >--v c^ t-r i-N ] J >« ^ >« a m I u o CO c 2 i s a c : S o : 5 .2 5 *^ i 3 Q ; Q •*A « 3 B O 1 1) < 3 1 5|^ i i > 1 1 I < J 1 ' 1- 3 J 3 s - is -0 s.i y a ■ s! 1 ', J ■ li) -pa.' 1 . o . >, CO ; t:° :fcpa 3 c C > K o c » ll Emmaton Three Mile Slough Ferrv San Joaquin River > t c c o: a 1 ;S a o ^ ?- = CO : s 1 Ii i s! CiJ - O J 3 ; ', i 1 1 3 ; .^' 5.2 = •ai-ai T3-0 s a do € 1 1 1 1 s 1. & o 1 «: ^ ^ H ■» H •» VARIATIOX AND CONTROL OF SALINITY 275 1 01^ ' ro 1^ — •0 00 CO -«* > 'M 01 coco • C^l o-^ CO t^ CO ^- OS 01 1 ' ^ CO »0 CO CI ^ * • * t ^4 i QOOCO tC^ ss 00 kO CO to C-l cc ^ <0 (00 r^^r CO tt • • » • — ' * « * M 1 oc :> 0:>00 CO lO 00 <© "^r > "* »o '. ^ •c 1 i r^o 00 I CD « 00 -^ -^ Tf ~ 00 ■ ■^ ^ * CO -v • ,— 1 , « n 1 .t^ * . ?oco t^ to 10 CO C*! ei ■ • CO 1^ « CO . .r~ 1^ , 1 « ^ 1 * ^" • • ♦ • 1 * « ::::9S QC ^-^c } COCO C^ IcD '. ^0 1 i« u- > i 0*0 i»o I ^j. 0^ '*a* lO ' — Oi • O OS CO Cv « * ^H > tt 1 .00 • tta 1^ . . ^- ^ ' cs -^0 — to ' i « » c^ ^ • > 1 lUi > >t* CC 5 , • CO tOC^ « 1 • * . '■ 1 • < * •*— « • 00 — -^ 00 10 »0 WD «D <3i — -<»< 1 — ur ■ 00 .—1 1 Tr CO lO CO 05 1 C^ C3 COJP ^ « * • « • r^ • t so .t^ ' 00 COOO" > OS CO ' ^^ CO CO CO »c CO ^^ 00 GO 0:0 C^ ^ ec-*- -» « * -H 1 1 1 CO c3 i . rsj 00 tC CO CO •^■^ • * Ofl * c^ ♦ 1 1 1 f* ic > 1 +— CO ■-*« — ' » ♦ * 1 ■ * ■*- * * • 00 wa-^r OC l — C£ . iO iC •— " 00 - CI . t^ 00-^00 CO ■ 00 00 » to CC tO:c 5 1^ If CC i-i— » <■ 1 COiO-^ * * 1 • ■* oe ! ! ; Tf \ ; o5 '• -^COOO '< CO !t- O-«*'00 t* 1 CNI CO »— 1 • 1 1 > * 1 1 CO 1 1 • 01 « ■ • > eo - ♦ -•— * • * _ CO 000c . . . - • 1 ^ 2 1^0 w: I ; ; ^ - CC '< CO 1 ^o -V QOO '. ; CO r^ r* to ■^* ti^ — G ' CO CO ■ « -* »ot^ H- ' (M - . * * e r^-^t 1 ! 1 -^ ^C . csi a > i-^ •0 to c^ r- CO i ■ -^f :o * * c IT ♦ lOO Ci CO c^ CO CO — * ■^ « 05-^ I • I CO Mcq OC , CO CO > coc^ i I to to to 1 CO CO .(M cs • •♦— CD ■ ICO CC . ^H tO-M -H * * * 1 t * ■ * ' • » » » iO •* 0>TP ' ■ ■ CO '. • CO t^c^ tn , ', Oi COM c ' CSCO 05C^ tOC^ C4 « 1 1 I * . ■ ^r -^oo-^ 1-. »o 1 • ^- • C4 * ; ; i'^ M b-COOO OSOOCfl * J 1 r*co*- * » ' * ' ' CD-^ ic :o 1 CO to ■^ CO ■ ■ CO »0 COCDI^ > ooooo to to ' * ■ C^ CO * . Oi C0003 -- >• ^ ; ; ; a ; >. B 1 1 1 : 09 ; ; ;o ; oa m ^ 1 i ; ; ;§ ; i 2 • s § Q a "w ;::'•§: 3 a a 2 • ■4^ > 1 1 »— 4 •2 1 1 . tH) ' ' ' ' t- ' ■ 't— 1 1 ! t S3 1 is '1 i •u c > OC 1 il s c c ° 1 c > 1 Si N S _c "5 E a U c > >> w G c '.J3 :|S J2-C ) c a -1 c c > ■ ^ gal a = be 1 E s «. C _oDS cd -5 3 ^^ _ o.S >a3 ♦J c: = s « « Sod 1 > 1 : «>sa-^ S^ t: i S £ _2 Blakcs Landi Quimby Pum McDonald Pi ^ a c5 § 1 ■a ^'1 c c E E 1 C 2 -1 a: > a. ^J2 c a £ McDona Zuckerm Orwood East Co pany". SS is an > S > "x I— « '-i 1 a a 1 < c E J3 72 ?>2 1 g 1 6 > 1 9 •< 270 DIVISION OF WATER RESOURCES •0 V 3 C 'S c ;3 o < O O (/3 U b z <: H C <: o I O H § u < w z o H > U O H Z i CO o o o o t- o-*^ > ' < coco t CO •M • # •»~* III 1 • 1^ o ' o OOJ CO o ' 00 1 -^ CO CI > ^ oo OS ^ 1 C^ -<**cc r* o: csoo ■* s . SSi-I to • ^H # 1 • •raci -^ • CI w^ * •*— . * CO o^oo coooco oo 1 r~ . .•»(< — coco '^i . , ^fl ,-1 ^ rt 00 1^ CO c^ coo; 00 to . -1- 1 .-1- * M ^» • -*-» 1 o t^ oo CO »- CO oo 't^ ' •^ CO OS if3»C^ 2 o OCO o » • I • +- * SI o" M o _a X o t-* CO CD 1(0 oo -* CS| CO i-*-* CO ooooo k. p. s t-^ iC lO ^- Oi t* CO CO OS CO r* 1) CO OS oo CO C-1 f-i r~ M — • >j 0^ <« * * -i—* * * B o M '5 >) 3 o (3 lo o ,^ oo CS »C oo OS t IM ' CO OS r* ^"^2 '^ lO co»or-ooco ICO ■*-••— •o •^ COOO JZ 'o ■^ IC r^ I-* TT ■«a'-t— ^ 1 ' • t^ co-^» « » * 1 1 • • p ^ ■"^ ^ 1 u u c oo . -*f CO i CO ' l« CO OSO 3 TT . r-. c^i < CO ' CO Ot^ , "ca Oi O o (M COOO ' < > r-^ CO =:o CO M ■^ OS — « OS(M 1 ■ ■ a Ol^ 3 o to W3 t^ coroco ' ' ' * CO <—•• tfi • H 1— 1 t 1 3 '"' T-t * « 111 • 4) c i i o CO GO r* "^ "O 1 i I-- 00 ^s^ N 1 1 (M CO OS OSCO CO 1 1 - r- 00 'TSlO H oo 1 , CO 00 >0 CO CO C^ 1 ' •^ (M-»— • • * o , •— t CO i« w^ 3 ' O o ^ -<»- — . 1 Tf 1 00 00 <^O0 U) 1 o 1-^ CO X: OS 1 'O I t-.COlC c CO (-_ OO CO '(T t- 1 to 03 O *-> O C^l M« r- o 1 ^ ' •o CS» u> ■<*' lOiO ^CO . w . > » TP • 1 >< 1 ca s ;1 c s : s : 9 ,_rt 3 CO « ; 2 ; Q *5 Q : a ; o Nl •a 1 it ; i i *k £^l c OS £ '.£','.'. ; £ ; t . ; 1 1 1^ t 21 a 5 i a 3 a £ ^ < ^ a 3^ I 1 1 . o o Sg C3 GJ o > '£ e c cr.S,-~.~-^-a *- U ^ -^ ^ ^ « = ■= ^ cs rt O o! S •- . . >mSco co-r o CO S-^ "" 2 g ^^ a 3 a "S a a* .'r._ c ^ w «^ L. t-^ c c: bc = £ = .._ ^- o. ^.=^-3"a£cs- ■;-£r¥. 'S t5 O ■:^ a ■s^t; i s s g >,o S a o 278 DIVISION OF WATIOR KESOURCES Oi 6n £ X S Q f/1 ^ 1 < o •0 H S: 4) hJ *J ■J U i^i Q 'i i 5 CO a o n < 3 n 3 U ►-> o < 1 1. N S O in H w Z HH ^ CO VARIATION AND CONTROL OF SALINITY 279 ooo IM -^f -H OO OO 3 I/) > SI .1^ '«.*• O OS S^ . a C9 . a a o, o ^ 0(M •p. 1—1 -w H s O o 05 Wl 03 -a « f:J *a H P -o O fit ts h ed S 1 03 o •3C a =« a^- §co Og I^ r=E-i (1h„ gm OS . s& SO .2 C o o a '-ja CO" M CO ca 3 >■ •Bl^ -o port, 1927, st Contra C Steamboat en Island. 0) -o " S -■» w fc nal r heE land , Sta K _o c "= ■"►2'^ c o g tion aft cords in cords ol Grand Camp 4) u CO en t. ti CS OS J3 a JJiiaa 00££,''« 280 DIVTSIOX OF WATER RESOURCES <: CO o u CO O z < z < w Oi Hi cu A 3 •<^ j: < "0 H * V U 4-1 3 U ^ C D 3 O u n C / a d hM 3 _>. C CO n < n o 3 la ■-> ID -J < z S5 b N y 'sj c: H 3 z u C S c < y a CO u *-' < V V) a w' S CO Z J) H ■«; > q: u ss .J S o>oo ■^ to OS ^^ OS U3CO U3 u^ IC O W5 O O O OO 05 ■<»« 1^ OO -^ oo « — -H oo §" 5- 3" o.. c a CO B J3 BQU I CL OB c i* g ea eQ-< CO HO Mi mo o.= (2s 35 <; c i§2 S .1 CO H ooo »- « a 2 en N U DO fl omcj&;Sco< i VARIATION AND CONTROL OF SALINITY 281 « 00 oo « CO ooo iO — r^- >0 CO 'OOOOO "*»• 1^ t- csi oo > i&^4 a»ooo to o ffCCO U5 O tC U3 O ^- t-- r- 40 «— lO ^ UD tO oo tC CO c^ tc oo ;:c ■^ c* — • OOiO lO o o o l— " t- !£) CO ir^oci ooo CO =0 iO oo tO 03 O K3 »0 lO Tf TJ< C^ lO CC 03 t^ iC o f— QO CC ^ = o :t: "-^ 5= P r- — ca o a- S a -s: c m ^ O ^ o >- -3— g c ^ mm UC/J «"o csii; : :1? I" . c _> |-c--^.= S (/> r-C — ^ — ^ „• _• <0 ,? X c c — Qi a a 282 DIVISION OF WATER RESOURCES •0 3 C s z n UJ CQ BO ST u S o 5 (3 3 ±: c CO a E a) . < 1 1 r 1 1 ICO COCO r- ^co . II CO C4 W4 eo ! 1 \ lo ' > , , , ,^ . .^C4 <— t •• oqr^tocoeo • -^uin C^J 1 . 1 » ^ > •* • • « • * ; 1 ! ! ! ! loo-^M CO Ci CO ' 1 ! ! ! 1 !ia taao III! tO — com 1 1 . ■ 1 O ^ CO CO 00 o-« 1 t~ «e<> is. ^tt 'M •Via C4 '■III!* tt • '^ OiOiCOO 1 -o^^ ^ Oeo • : ; ; ; 1 lo 2; £2 t^OJt— Ot^ t 'OOCO r^-^ I eceo lO oocooc^ioi < -coco • -1—* . ^ d M - - - - 1 > * « * # ; ; » ^^ ! \ • o ' < 1 om CD wH r 1 leO -H • ^^ •• 1 1 ICO ' < ; ^^ cs ! I I* III • 1 1 1 1 *~* 1 1 1 1 I I 1 1 . . -^ ^ WCl -^ r- Im* M^ tf 1 1 1 1 w !-• . 1 1 1 1 1 t~>a 1 1 1 1 lom C3 (N 1 ■ ) 1 1 > ■« * » ^rSw^ ''II ^ • * • I'll *o 03 ! '• > ' o o ' ooo o CD <^ !^ 1 1 1 1 lo 1 •^2 -^ 1 1 . 1 oico 1 CS OS OS ^H 1 1— 1 TS a CT) 1 1 1 1 OO i eo (M « * 1 1 1 1 1 .Cl^ ' »oco 1 ! 1 1 * I g o OO ■ 1 O ' ' 1 ^»o t^ c^ ! I 1 1 ! 1 ! I looit^ o JS OlOO 1 ' U5 ' ' < OCO OS lO . 1 1 1 1 1 1.1 Id ex CO t>- OO CO 1 "CO ' ' 1 cocsi *-l * 1 1 I 1 «-i-^ ^ d * l_ o w^^ ! I »-H I 1 ' V * * 1 I * ! 1 . a *'■■'''' .2 o om -tT 0-* o '< '< rOO . . 1 00 -^ '$-1 >, ^o O CO '— iO • ' iC^ d . . . -r oa C3 Q IC ' eo ^ 1 1 1 1 1 1 < • ^H tt » 1 1 !• # 1 I i I •V -v o 1 1 ic o '1ft ' eo ^^ OO e^ ooeo '- O'W 1 1 »0 CO ' ift 1 c^ Cl OS CO (N 1 "Gt a CO 1 1 -^ O " t^ ■ CO(N • * > •^ kC • I O • 1 ' O "^ CO CO cq CSJCO I 1 1 lioo ' '• (M OS 'a CO t 1 ^ 1 1 1 co-^ UD ( 1 O 1 ' ' C^C^ OS-< 1 I ■»U5 • •*— ♦ 1 1 1 ','^.^- 1 1 10 -"f "? '— < ^1 ' ^ 1 1 1 * • 1 aj 1 !* ! I I 111 • 11 O i^ CO ■^ .iC^ I 1 1 1 loo 1 000 CO 1 I • I 1 I 1 CO Oi kO kOC4 I . 1 1 .«■» . ^. » -1— • osoq^ 1 1 1 1 ■TJI ^-i'.-T^ I 1 I 1 • 1 t 1 1 1 < < > • tAQO oa c^w Cl-^QO 1 1 1 lo 1 1 t^ t>- itO t 1 1 i^^l^ -^1-H •^eo* CC OS lO 1 w ■ . 1 .t^co w • » * 1 I I 1* 11 •co 1 1 . t^ 1 1 I COC^ to , . 1 1 1 1 1 c es k. >. > S i C (S ' .2 5- O 1 > • J ^^ i : i i i i| 3 : ■ : ' . ■ ^i 3 CQ San Francisc( and Suis Tihnrnni Green Brae'. Black Point'. Crockett'-.. Port Costa'.. Martinez' Bulls Head P Avon' 0. and A. Fei 0. and A. Bri , Sacramento Collinsville., Emmaton_ San Joaquin Antioch Sherman Isia Jersey San Francisc and Suia Tiburon' Green Brae'. Black Point'. Crockett'.-.. Port Costa'. Martinez'... Bulls Head P Avon' <-< -o-o B a a a do M o 1 1 < £ r VARIATION AND CONTROL OF SALINITY 283 •— I O Oi «D O COCO coco b- O Oi CO kO «-" O lO lO CO -^ — OS to 4/5 lO TP OS CO lO ^ lO CO O CO oo o oo ^ ■*r o COCO CO ■«»< i-H .-. -^t* W5 ■<*< C^ CO -^ CD «* t^ OS COCO oo -^ OS O 00 Ol 0(M CO ,-( CO -^ —1 1* oooo — CO ^co CO »o CO '* ^ CO COCO OM5 ^^ CO ■<• *OQO c»co r*>c OS » coco OOOi^ r^ QO c^ o OS ^ ■^ lO oo OiOS OS O O W3 coco CD O •O CO io»o OS CO i:0 . . c^cS'eoc 11 I 284 DIVISION OF WATER RESOURCES J, < o u u •0 H 2 w .S Q c Z EC 3 O 3 to C c to CO u S 3 o 2 o C»fl ^t^ 00 05 ^co c3 ^ Tf CDiC CO » coco 00 'S 01 coco C^J CO — "CO » ;§ * * o W3 01 »o o »o 10 00 05 05 C*! • CI ooo 10 -*J« -^ ■^^1:0 oot^o t^ iC rf* (M ♦ « — « CO * to lO OS ■^ 00 t^ CI 00 o ^t * * CO ^ I-- 1 ■^ — CO CO m • • W5U5 kOCO CO GO Tf CO OJ — rvl « « • 1 B a. w Q C (0 k a com ■c > ancisco, d Suisu C - C3 1 s 4> a; t- be E > eg ja 1. a ^ s s Q 1 .0 a s o o Oh c « c ^ •2-2 |cS o 4> £ *S VARIATION AND CONTROL OF SALINITY 285 < T3 CO -z oi -S, Oh f 3 O j: C3 Q 3 O M oo " I o »o 0U500 O3 00 O C30 t^ O QO Oi CO c. E a CO o o Q. CO "00 ■JS ■ CO "SCO a. 5 O.: O •« lO o o o GO O t-^ -^ C5 CM ^ ^< »0 OJ • ^H o ic »o *o TT CO »0 C^ ■^ •O C^l OOCO ooo CI CX) lO -f "- -^ »0 »/5 iC 0*^40 :o CO CM c cs cacQ o 3 .2 :3 M50 a; lO i« O lO COC>ll^ !-* CM or»u3 o o Ci ITS 1^ 00 rt . rz: t--r: fc. o HOcQoeuSffi- ^ w c o "^ c oo CMOO CM -H O »0 u^ tC O C5 o o ^ cc CO '^J I? c 9 in :=Oe-ie o S iU -^ « 286 DIVISION OF WATER RESOURCES 3 C S z 3 3 .J < T3 a; ■& 3 o o 3 O CO O 3 /, < N V) a> (^ v2 H T Z :« u C S r -s* u cn to u < « w a e« E CO V) Z o H < > S S >< H »-4 Z ^ w 1 o § o o s. 1 1 c 5" '5 "« CO .a 1 E g :g tnta iiS 00 COOOO»C ' ' ' :§ is 'CO s 'itn i ;g is 'CO ^ 04 1 lO ■ ^ S'g i s •^ ?!?•» w w 1 ;g ;S ^^ § 2 • m to OinoOTr oo o • g ; O > • • ■««» < C4 §2 C^ C^l • • R i ^ ,s is 1 ^H g '22 •V >o C4 ^ !»o • o O -tOiO • . »o g ; 3 lO '■ 00 o • CO I CO t « ii: 1 * g{2 • 2 « 'oooo . ««« — • • • is ; r ^1 1 lO f • is : ■ • * o • • C"! o ■ CO ' i K ; ; 00 > g 1 San Francisco. San Pablo and Sulsun Bays Tiburon' _. . o 3- 1 as p San Francisco, San Pablo and Sulsun Bays Tiburon' I'.l C03 1 S •4J s Avon' San Francisco. San Pablo and Sulsun Bays Tiburon' „ ' as - oi ro (N# OiOi •^ »o ••— <>» --l OO 00 C-1 CD CO o to ooo OO CD O O O iC -^ OO ooo "'J'^^OO o (M — I r-« ^ ■«}< *0 »C CO I--. CD CD OO C5 IC OO r>-cD OO ^ 00 OO CO CD OS b- O O lO "^ *o CO C^ CO O o 40 '— ' CO CD CO "0 o CO - OO ICCO TJH OO TT O OO OS *o t^oo O CD liO OO Tj' CO OU5 t^ CO O 3 gco o»c 00 ■* OiO COCO a X3 CI. CO c S* CQ QQ «0 _ 2 3 ^ _*. O -*^ w S 4J dpQpL, -te o aj^^ o (^Q Chm rS £ « 2 fe^3 > pbca es-r en > O c cwtf; f^ Ss^> J= £ « HOCQ a -^ "E — OSu ^ 3 > . . Sm ^ = fe a' "a a s. 288 DIVISION OF WATER RESOURCES V 3 C U c o u U OQ CQ O U in u z < b Z 4) < "o X D Z <; < H u Q Z o H > u CQ O >^ H .J < z CO D -'l <7 CO < 3 ►n O r y, l^ N H 3 Z "^ U c S c i2 « a o c. c o s CO o I oc/5 oo eo o OO ^ c« O Ci o C^ O CC CO ■^ o. 00 ■* oo CO »o 000 00 ooo = cj £ 0 1 1 ioa>» ! ! 1 t- ' 1 ! ! ! 1^ 1 ! 1 ! ! ; ; 1 : :g ; 1 : ; : t 1 1 1 i« K^ ! ! t^ I o 1 1 1 1 l- 1 1 r^io 1 1 1 lOtO 1 1 -♦— 1 I 1 i i io2 is i i i 1 i.iiC^C^iC^iii CO 1 ■ <^ OOCS ' CO 'i 1 loioousoo 1 ! 1 1 1 03 O i-H t^i-l ,-1 1 1 1 1 I OiCCIM !M 1 1 r* 1 1 no ■* i>o 1 1 ! 1 ! iiooo * 1 CD 1 1 1 1 1 1 i-H ■CO t« 1 1 1 1 1 1 QO I I 00 ' ! 1 ! 1 1 1 1 loouo 1 1 1 1 1 1 1 1 1 t^ OO i ' -^t^ 1 i 1 lO I i iO*-<0 I : : ^ 1 oioio 11!! lt~-a. 1 ggS 1 1 1 1 I'-S 1 ,-7f-H'»-H I I 1 I I III CO III *-H m ' 1 loooo 1;- CO 1 CONM ■no 1 I I •0 • o-« 1 05 l-r toco '■ sss o to I t^ to CO 1 -X) CO ^ M-^ CICOC^ CJ » « o »o coco 1-1 0^ 000 > t~ 1 1 to 1 CO ot- ' »o 0> i f-1 1 1 tooo . ■* ^r ''J' OS 1 — _c^ ■ cq « o to 1 1 OtOtO UO COCJ CO ■<>■ CO o-* (-* PICO — _CO ' O IM •1— « 1 1 ^ i-i a ira ! I O-*00 ■ 'n ■WCMC^ Or^to o ■_eo« o ^-^ o o J3 o C o o ! ! lA • < r^co ' U5 o> 00 1 p. e Tjl Oi 1 1 1 1 « — to ■ CO 00 to , 1 coc^ • a> .s o o Q ♦g o \n 1 1 1 1 c^ t^CO'<1< COON ot^co c^ O«eo t- c^ . ■ CO «-< C4aoO I 1 S ', ', \ S '• c ! ! I S ; : : ■s : ; ■^ : 1 WJ J : ; : "S I I I ^ ;S 3 ; ; ; 1 '3 1 ; ; Q ' . ; B '5 I I I Q . ; : Q : I 3 ' I I (f) \ \ , » I lis CO 1 I ; 1 i i& « i lis M : ; ; c M ■5 ; : : > ; 1 > ; ', 3 '111 > ; 3 ■a ; ; 1 o s "111 <£ : K ; . § ; ; ; 2 ; ;-a cc ; ; ! ; : i c ■5 1 \li ; 1 ^ 1 1 3 ! ■ S ■| :-Xi c ; ■3 1 1 e£ . B ;'-3 2 1 >.s a > E ' 1 O* 1 ; § ; t 1 t-TS CO ; fc-E E 1 |aj 1: ^ ■ ^ iS? a ifcM Si § S :^" c C9 S ;fem 1 ■0 £ H B 1-4 0= B~ i a J «S«CJ c 000 Ob J <: 000 OWH «;^o 000 a * 1 a ;> ■ S E I I S s 4 1 u •-1 > •-» •? < VARIATION AND CONTROL OF SALINITY 291 O t^'"** O - 1 -^co r>. a> ■ oc^ OO . CO 1 1^ ■^OO Tj« . OOCD CO lO^H* lO • 1 CO-H r^ T»* cn w c^ r^ 00 • f eoc^ C-l i-'N M»-t coco ' Oi I CC05 W i 40 • lO CO 1 00 '• a ^ I CO . t^ 1 » OO ' lO 1 CO »-* »o 1 CO 1 1—1 CO t kCCO CO lO -o- -^(N 'COC^ t^ 00 CO 1 * OO . »-« »0 ■^ 1 a> ' CO t c^ C« 1 ^QO '' (^ 1-^ t- -*»< o 'i« C _, ■^co o ' iC ■ ' 00 • coco CO — (M O CO CO > « c^ U3 . 00 >o -* ' cm t^PO ■^ ^-t lA liO • CO CO CD o 1 ■<*< 1 00 COTjl CO us COiO lO ' -^co ■^ t O 1 ' CO ^(C ^H 1 ta CO ous kO 1 »o CO 1 *n 1 1 1 « CO ■^ -^ 1 CO CTSCO OS CO t^ ; 1^ CO ' s o> 1 r^ 1 (N c^ • coos 03M OOO -<* CO c^ CO M o ■ o 1 CO t 1 CD 1 ■^ CO CO CO »o • US- ,-- -^r ^ CO ■^ OS \m CO '• C5 1 OO MOC O i 03CS — to *-H >o ' CO 1 c<» COiC -^ ■ tT CO CD lO o CO CO OO ' CO • CO ' OOW3 eow s w^ »-4 1 »-"0 o "''c^J I !'S 1 : : : i.i ; ; a •s Q 1 ;_rt I ! c 1 ;!§ > r O 1 :^ 1 : M "3 1 Q < 1 1 1 s Q «s 1 Q ; "a e e Slough Ferry Bridge > ir c '3 > ; £ : o ; M i 3 M) > ir c "5 CO 1 is > EC o r > ; oc : C ' '5 '. if : : OB I > o c i to > c 3 1 i i1 feCQ o > s «^ O 1 1 Cbca E P > ^ k. tfl n « U Q OOUi I 292 DIVISION OF WATER RESOURCES < CQ O U W o Oi ii 3 < O X •< n •0 H ^ 3 >J w (I) t-i ••* Q 3 c / c!^ l-H >, 1 O- a M < •J fj 3 u i-i u CQ 1 N o O ^ H -i Z t/i M c 2 r < OS u ^ < to w 7), («' E ^ c/o HH H < > Oi u g < o o 00-* CO lOTt" lO 0000 00 00 ^*4* CO oc»* ■^ oo coco o»« « .00 ^•« t^ t^ a> ■^ OS OS CO c3 CO . t^ tO(M •flTJ o * CO • o « o O )-<)• •^ or^ ■■* -*iO CO COOS CO M cq CO ■>f 1C3> lO ■n » .CO -*»C wo ■Hj. ^ ^ 00 a> oo OS O '(M 10 . CO CO C^ CO « (M # o o o O 10 r^ c»coc^ ■^ t^ CO a> . .CO ■» . CO '.r <— ^ co« cq '"' o o o O '• i iQO !c< ) OC^-^ 0-* 1 •^ c^ CJ 05 ■ CI (M 00 coo . o CO OS o CO t^ ' lO CO 10 C^ C^ .^r w^ . o (M ^ »-H * ^ * * Im o o UO o ! ! lo M -^ W5 •«*« (M -^ I o •o oo Tl< 1 1 CI .oo TT C^ CO Tf. -9< 1 <3 00 00 o t^ ■^ p 1 CO .CO kO ^ 1-1 CO -H t o O o -c to o o o o 1 1 ''-v 00 10 ■'J' It. , a B t-- CO CO 1 1 a .10 o>c<« 1-1 cq CO . CO M CO CO > CO cc^ CO »-. . OJ .s o ^^ '"' 1 1 •^ . o Q ■g ; o UO OiO '• OOCJ COOOkO I ot^ 1 o CO oo— H ■ UO 000 •^ oaud < 00 -^ . •3 •**' o OOt^ ' ■«<_o>co CO ' C3 D. 1 1 1 C o o o ; 1 '• 't . Oif 1 o •^ CO . . oo . 1 ^f 1 ^- CO . M t- U5 o_ 1 ■ CO . 1 . C C3 «3 o o CO 00 o en ic^ CO . t^ s i CO ' OC» • o CO o g i i CT loo CO 1 1 00 oo t^ OS 1 ■ CO .10 CO ' M 1 1 o o oo 1 oc^ 00 < Ot^ 1 t^ o lOiO 1 t^ CO (N '^ ' CO-* . CO t^ 05 03 CO t * 1 CO < 1 1 cq (M O 1 1 CO iOO CO 1 1 M 00 CO CO 1 1 CO 1 CO >« 1 I ! ^11! a CD > 1 . 00 1 ! : a Hi ^ 1 c 1 1 I 3 . . . ,» 1 I 1 '5 ' ' ' ^ ; O ; a : c 1 ; I 3.1. W.I. ■5 ' ' ' oil e ; w ; ; ; b k fill •- 1 b 1 o «> £11'^: ffl -0 c o ^111 > : > ; = ; i i « ; ; ; £ ! 1 s 1 0) 2 ;.!& o ; c ■ 0} ■5 ', C 1 e ^2 1 s 1 i-a,j E ; ;cc-E <« CO fc E : g ; 35 Im S3 g : :--3 g ia"^ 2^ •n 1 g i-s^ g » . »CQ San J( Antioch Jersey Central Lan ■s ■s ■*3 l| li - i S> 2 <3lg=! 3 o-9o =iii.2 o o o o<:o O OHH« 43 ! §, 2 ^ S — >t a» ^ d a ^ s S 3 •-9 VARIATION AND CONTROL OF SALINITY 293 -*** rr CS O t^ 03 o ccooco»n • O 00 CO QO 1 (N O 03 t* 1 o»n ■ M-cq 1* COC^-«J*000 O ■^ CO -^ CO i-i -i* M ■^ CO ooeo o 1^ i-« 05 (M 00 c— t^ ^ ,-, .-( no O OO -^ »0 W CO CO CO CO — • lO •— < •— • OS l^ CO lO '-' »-' OOOCOO'«*< ^H -CO 1-1 l-H O OO O CO 00 OO •-' 05 Oi t^ O CO -^ '-' OO CO lO »o •— ' » CO O Oi 05 o <:o O CO O i^ t--. r- O OO lO**?^ "^ CO C^ 00 -^ Oi Ci CO O coco ^ i-H lOOcO-^cOOOi— 'O eOC^l'*»OM/5CO- kC Tf '— I ♦ o ■-*< CO CO O *a cceo C5 1^ o OOiO CO(M ■^ W O ■«*' t^ O OO Oi 00 TT i-* oc^ooooocot^co«-*iococoo COC^COlOOOUSCO'-HCS'-'i-H.-ii-H O t^ CO ■^ »— I I— t « OOO W CO CO CO tOOO O lO Oi lO ■Tf CO i— < lO OOOC^OOOOO >— ' 00 00 CO c^ OtOOOC^COOOCDC. to lO '-« OO OiO oo-^ CO CO lO CO r* W3 CD CO lOCO f-H !« O CO CO lO CM OcOO-'t'C^-^l^iO^-CO iO(MCO»-«OiOSiOTrC• O OS CO 00 '— ' 00 OS b- CO •* 1— " CO eOCMCMC. to CMt* OcOQOQOOOOO-^cOt-^OOSO ■^cqcoOt^oooococococMco OS t- CO CO »— < CM « OO-* CO CM t^ ■* OO U5 Oi iC CM lA COOO CM Oi OO CO r- t- b- 05 CO »f3 lO »-• OO 00 t* 0» CO -^rji CM •*** CO CM -Tf< CM OsO lO CO »0000"*-*0»-icO CMtOOSCMCOOt--Tf ,-1 t^ lO lO I-" CO O C-1 CM 00 <-- O CO ' '«!f O CO Tt* lO 00 00 1 OCO-*-* — ^ 1 IU5CM 1 CM CO ' « '"' 1 OiC eooo irtc000005*<**000 CDiOOOOCOI^OCM O CD CO ■* 1— " •-< •-» CD CM lO CD CO O o r^ cob- O CD coco 09 OQ IB C *^ 1 .S . 2 a =3 □ > ir e c I C3 J «| g « ; oPa.-S S 3 s c a s> p « fe 3 o a: to c . da C3 E c c O OJ O) tt^ -** -^ ■^^^ -Has f-OO c co-g o a «£oh 5- CO c 3 CO '3 (/> ■o c > -2 >> _ u bfi J3 . . ■ . 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J3 to u D j^ C CO n •< 3 t^ 3 Hi ►-4 u ri 2 C § «) N 1) O v2 H 3 Z '/) u c S c CO u <: (« o w a f« E z Ji H < > a: u V) n o >- H HH s ^ w 22SS OC4 ' * o 3 w^ C4 TT CO Oi cO CO t^ ^ c» 00 CO CO O OOCO OO lO -^ 0»0 (N 8NkC"»t<«O4OOJ-^00 OlOiOOOQOr^'^^ o CO ■^ CO OO CO OS CO »rt ^« t^ cooo O I^ O CO 00 — -^ 05 M CO lO ■^ "t»< CO OO -^ CO I-- 00 t^ oico - (M 1^ OS CO '* O 5 O -o-o c a 5 Q > a. n ^^ Ui ■ -Ji Ji C C I- s c -= Ecj V 0) a> =. .fc. tt4 *-» ♦J 2 3 e3 ce 03 S » V, ^ a: c« -1 a^i a a OOCO OSd U^ CO oa O) ^^t.% kC CO 00-^ OkO Oqpooci CO or* — oocoeoeo O CO 00 00 •^ CO OO O ooo -* ■^ o IC ooo o »o O C0»0 CI kCCOcO^ ITS OS*-" Oa OcO-^C^ 000*^0 cDCOC«U3 0r«»0 ■* o»o»o CO lO CO ^< lO CO lO ^ to CO r* CO t* OS Oit^eOco OOOOO CO 00 »C CO C> CO CO U3 lC CO CO CI 00 r^ CO o O cOtO<^ MOOiO kO CO ^< 00 CO 00 Oi CI 00*0 O'^ s ' S 5 - a « o i"? >:;.S » « 5 i;"S S.5 =.S r! a « 1^ " £"5 ^.5 5- " 3-~r= O 1. 1. . _ offl I oooo -^ O 00 r^oo to Oil* CO -^ »c coo a> CI OS CO OO kO CO ic 2 s, a GC o fc I en c - a C a « ol^.S OWHCS o l"? w a 3 O VARIATION AND CONTROL OF SALINITY 295 QO I I COtO O U3 WD ' t^ 0> CM ' < -^ OS « 'rt to t^ '— CO C-1 00 O O OO CDCO ^O 00 t'- f-" i-> eo«-Hr-i .io CO CD -^ ec U5 ^ (M 1-1 r-l C^OCDOSiOO^iO •^ — iO lO •-H ■^ O CD CO coo C<» 1-H l-l »o o CO CD cot— ^ OS O CM T«t -^ OO i— " OO 00 lO CM ^ OOCD xn CM CO O oo-^ r-l l-iO «-• 00 lO CD Ou? ■^ GO OS CO CO CM 1-1 OO t*00 I ^*< OO to CM TT CO o to 00 CO CO Tf CM .-« -^ .-« CO CO CM i-< 1-1 .-1 i-< OCMOOCOCOCOCO"— " CO CO -^ CO CO O to I-- OS CO CM 1-H 1-1 ^ 1-1 O -^ -^ CD ^< oo CO 00 CM CM 00 -^c^i ^ to ■<*< coo Oco C^ CD CO CM 1"^ CO OS ^^ to CM oo ^ O -^ CO --< lO t— CM CO OS CO CO »-t OOCO OCM CM OS CO CO O O CO ■«»< TT r- oo O CO O CM O CO •<*< CM i-i »-i t-i i-t .-H t- O CM oo CO OS Ot--*'^ CM OS'* CO CM lO CO to CD T»« to O-H OStO-^ OOO to to QO ■rr to o tOTj'CO'^OOtOtOiO ■^ OS oo Tf CO* CD -^ CO 1-" O OS t-^ 00 00 t— CD t— oo to CO tOOCMOC^JCOOOCM t-c0O00-^0000- a I a a > rr^ 1^^ if 5,1-1 >.i-ii-' c c c C c a •= EO^ V C 0} =. ^r -«-■> T-l -*^ -t^ O sia a a OHOO CO c; IV <:.^ i>, y-, ^ C :20 M Ji BID t §T3 a go t- ^2 a> « o ^ - =« ^ '-'- ffi ^ *» Ck- = =3a^.2.§^5iS 2.«§£ I s 2!)6 DIVISION OF WATER RESOURCES < CQ O U W •0 3 C c d ■O I'Wt^ ■* t •**-«fOOOOOOOOOOC(M'^ eo to ' CO c^n-^ I ^ > ^«iO CO > ■*CO-^^C^t^iO00iOCO OS ■ oo • c^ oo^S . o • CO 1 « ll^OO ■*fOO-^'-*«OOOCOO'<»'OOOt^ CJ O to OO o « ; ^ iinxs CO-fiOOOC^iO^OltDC^iOM CO ■* CO 00 ^H 1 00 iOC^-H C-l^-^ -N^» -^OO CS| M # • CO I Tt* -*j< c^ (M -^r Tt< . . iCift e^ O 1 c^ C40 ! ! 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B ! ^£e^ = 3-.5M-1 offl"^ '-■^■=1^ o « o^ - E jq o 1) o£ - E a o 0) o 2 E'ssiiSSS a 2!»8 DIVISION OF WATER KESOUKCES in < OQ O O V) u CO a. u •0 H 3 J T3 3 O u D >, C CO < J U •-> f,> ^ ^ z < C N O O ^ H 3 Z « u C S C ^ u iJ < 10 (fl "a (/' E z H-l H < > o: U • CO-* • o to : o o lO lO liO 1 M o lo 00 CO IC U3 O 1 « ■« 00 00 *^ t-« CO < lot- OO'V OOTjl lO l«t^ CI lO 'oow 00 lO ^ ^H »0 "* >o CO ' <^ 1 ^J* o CO ' to < (TJ o OO 1^ CO ! r- ■ O 1 <» 1 • e<) o > (-4 1 lO • • (M L. 1 0^ 1 •*J CO ^ lO t^ CO o» O ''CO CJ liOt- r- -^ t- o> 1 00 o W3 o ! ! IM 1 O 1 1 o Oi o C^ 1 . M* « 1 O oo KO •^J« . 1 CO ' < o * ■ o o .13 o 4 OOO oo coco lO »■ o Imoo ! w lO lt~oo t^ -^ a a to ^ r^ Cs« . CO t^ n CO ' ■o 1 QJ * 1 S o ^ >. 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' ' o ??J3 1^ i i i| i ^ i 2 "5— J Pi .'," E ; ;c5-c g"0*J • Oh fe « t; O *3 ■« £ga.a l— (X. =3 05.2 PMPLHomncPu OWHPS fuetiOpapaoon ■3 § i 1 3 ■< 1" VARIATION AND CONTROL OP SALINITY 315 oooo Oi t-» lO CO • — t C^ CO (M CO O t>. OOOOOO t^ r- o o CO CO CO CO CO CO C^ OOOOO (M Tt< (^ r^ Oi CO CO O CD CO OOOOOO CD CO CO CT5 O CO CO C^ IT! a> CO OO ^* lO OOOOO oofM Oioo r^ I-H M Oi t>- n 2-a CO C »P3 0:=: c-2 rt c a ■<>-: a, a 3 a. CO c S" ea CO o CO .2 5 00*0 U- es 0000000 05 DO C*5 <0 C^ ■'f C3i Tj< O CO 00 *0 ^H > CQ t/3'E oj OHOS CL CO c a cecQ tr . c ^ 2 s BQ ja .2t3 « ojffl ._,.S 0== >> =5 it S 2 3 ffl -.- OiOiOcaasoa. !i«5 .2 c«-: OJ3.2 OHBS Q. a 3 ■- «3 •i a 6- O 316 DIVISION OF WATER RESOURCES < BQ O U V) o x: M u a li:! u a D. (A s 3 Q ^ a! < c Tt H 3 •S Q c 1) c 7. c HH u D 3 C K n < ffl n O •>, U »-> an < w CO 3 3 6 o H N 7, U U ,™ 2 < <: Z o H < > CQ o > H Z OOOO ' «o ' CD oo <0 »OCDCJ ' • ^COCO-^ . 1 o CO ! !o < > ! • oo . 1 r^ 1 . 1 . . . . (M 1 1 t* - 1 ' 1 >1 c 1 oo O OOOO < t* -^ o lO CO »0 lO T-" CO ' •^ Oi 0> W5 CO 1 '^ 1 I !o 1 ! i t^ 1 1 1^ 1 1 > 00 1 • O) < • > o o O O** -^ ' ^^ r^ iCOO Oi CD cOtH I (M CD ^ OioO cDC^ i-H ' o 'o I 1 I 1 O 1 Oi 1 1 1 ' TT ^ .05 ... - " 1 # 1111 looooooM^ ■* o i CO »0 '-I _o !!!!!!! fl '; a i a> \ 9 ^ to \ \ \ \ \ \ \ a ' o , <=&;::::: k > ; ir ; a o --- -^ i i i i o 3 , , . 1 1 > > > ; K ; San Francisci and Suis Dint Orient oint Davis roclcett' ulls Head Point- ay Point . and A. Ferry-, ittsburg^ 2 1 E ; 3 1 S : o 2^ CO 1 H i3 o ■£ (i<(i,om(noPL, O < ^ ; c 'i s 1 o B CO O. Fl tfe a ffi ■«! rt a u: n 3 V VlJl a U .3 £ & Cl> tS w -a fi a eS ■S! rt g ^ OO >> >, J3^ o O. , s H >. B C9 <9 O T3S o. 60 g ^ c « C B tM ^ O fn >> §■? £ SS S Fc fi B (U VARIATION" AND CONTROL OF SALINITY 317 00 r< (T *H >h' <: 09 u 1/) t-H u z <; u a; ■a b 4^ 7; en b; ii u (0 (U « s 1 Q ■ffl <; c "0 H 1 i z -o c CO u c o *-i 1 a n ro < V, u •-» i ^ 3 H (/J aj C n H N 4) O U u < CO CO Z o > (^ Vi CQ O Z O iO-»*o ■«l< •^ Ci lOC^J ' t 1 ' 1 It^ 1 1 . 1 O (M CO o oo OC^ t^ 1 iC io O oo -^ CD ■* > CO to o r^ 1-- (M 00 1-" ^ 1 OS ^ COCO CO ' o 00 CO^ Oi 00 lO (M 1 ^ l>. CD -^t* 1 o 1-H ' c? o ji: "c o 1 lo '< I It^ I lo 1 I lo o. S iO ■ 100 < 1 1 . ICO 1 ' ' 1 1 -H 1 1 1 -H 1 1 t* 1 1 1 O) «*^ .s o o >> Q i O O wr5 M 00 O ' 00 to O >0(M CD lO ' >o to 1—1 lO h- O CO 1 CO 1 COO ^ ' 'o .2 •^ CO O -> 1 l-ft 1 1 1 1 -^ C 1 o 1— 1 O ii«0 tO?0 1 OS 1 Tfi W3O0 1 C lOi 1 1 to 1 1 1 11-^111 00 r iiO ■ F . t ■* III 1 iC^ t . 1 O 005D-^»0 ' CD CD OO »0 -^ CD ^ 1 ^ < U5 r^cot^o^ 1 00lO"<**t^rH 1 th to CD e. lO 1 y-l ^H I t^ ^ 00 j > ' cl o > » 1 ' > ; '£ ; ir ; 5« ir ; £ ; 1 San Francisco, : Suisun oint Orient aint Davis. rockett' uUs Head Point- ay Point . and A. Ferry... ittsburg- O ' _c ' = i ; ; ;^ ; ; ; o ' S ' s e ■ '5 ', g ; San Francisc Suis oint Orient. . . oint Davis rockett' uUs Head Poin ay Point '. and A. Ferry ittsburg- c E \ *3 ! ; § : 2« ^ 1 .2 o = OS - i -1 3 '^ p^CX^C)mpQO(l^ o < OHOHOpacaopH C J -^ 1 1 o 2 i >-3 .'518 DIVISION OP WATER RESOURCES < ca o u o w T3 e; ij u CO cu to ^ 1 Q vm < < ^ ■0 H 3 .s C nJ s 7 (0 c d D 3 s < o •>> u >-, ^ ^ 3 H (/J u 6 C O O 00 ■>«< O ■* 1 CO t^ ooio->roo-* 1 c^ CO r~. »o "H »-« i-» 1 coco O CO < »o ' ^iO -^O) . 2 CO * 1 1 .'« 1 i . 1 1 .m 1 . 1 1 1 .C4 > 1 1 i 1 .>n 1 . . . oo (M oo>oooco i 1-H t^ oo 1/3 o co»o . Ot-«Oio . Tt« CO OCOOOIMOO 1 «o -H >OM OI_CO— . c» •"• 1 1-^ 1 1 lo 1 1 lo 1 'itr> 1 1 l<3> 1 .CO 1 1 If-t 1 .O . 1 ' ■^ 1 .CO 1 . 1 1 .s . . . CJ . O "^ OOCDCO . •"J* 0000IOCO . CO ■* lo .-^ t^ t . t^ U5COCO . GO C>) . ->4«'« i . ooc^ »-» . ja fe c o 1 l>o 1 1 lo 1 lo 1 1 lo) O. e 1 .O . . l-H . ICO . 1 1 CD 1 .CD . . . . icq . 1 . v < 1* II. a o M >> Q O . iO0«-H 1 CQ -*;3 t^ a .S 1 (lA . . . ' 1 1 CO 1 1 1 1 t . Tj< . . . 1 . It^ 1 1 . 1 C-l 1 . US 1 . . . >. -^ 'S "5 CO o O . OQOC^ lO . O ' W3CO . (M •o o Icooooio 1 oo . • . Tt« M ! lo ! ! lo 1 1 CO 1 1 loo . . *— 1 t . . *-4 . .t^ 1 . 1 00 . .CO 1 . . . .* I.I o loooooco 1 UO O Oi« oocsco . ■^ •^ Oi . CO coco . CO -^ -^ ^^ . to CO 1 CO CO '—* I t^ — . 1 lo 1 1 1 1 1 leq 1 1 1 ! . ICO • < . I ■f . It^ . . . . oo»« O-^J^OO iO CO o o 00 -^ c . 1 . . c eg cd CO 1 ea ... 1 . 1 1 es ' ea 1 o 1111111 O 1 1 1 1 1 1 1 ^ > ^ ^Z ill. ^ "3 . 9 ! ® ^ CS Q 1 Q : ■S 1 1 1 1 1 1 : o . Q 1 «>- « 1 1 1 1 1 1 1 b ^ ' £"1111111 tm k _ >» V o . >< « ? I g C eB > > ; c ea > 1 > K ; K ; 5« <£ 1 cc 1 1 1 c i J 1 ; i.s 1 b I o 1 c 1 c 1 '3 1 § ; O 3 1 1 1 t' 1 1 1 .8-1 1 1 :-i ;& 1 •S .S.S8:i>.«a O O t. 3 C8 ..JJ o ; c . O ) _c 1 '5 1 I; B • E ; 1 -s.zj 1^ ife : .s .s.si|t:§| o o t. 3 n ..IS ftnCLiOmpaOfl go.' .s ^.1 H 'S *3 a i o < o < 5 a o ^ IS S i t VARIATION AND CONTROL OF SALINITY 319 »0 »0 CO O O '^O OO O -^ CO •-"-HlOt-t oooooo r^ o r^ OS lo o CO -r) CO •-« Oi CO O O O O M< o ■<*< CO OO C^ OS CO CO CO O OO CO »-* oooooo 00 CO OC»*0 CO o o to C-1 OOU3C^4 1-t CO oo Ol^ lOO o o ^r oo «— " ^- »o t^ 0101^ oooooo ■^C^JOOO CO o CO ^ C-i IM 00 CO oo CO CO -HO O-^lO CD W OJCO coco oooo m 05 o lO CO i-" o o oooooo oo -H CO i -H r-- lO O CO CO CO t^ CO OOOO lO C^J CO -^ O OOOO CO - TT O C „ c CO o B 'S §.S<'Ef .-is = >.§! s o c E BQ > oc o o WH Q. B 3 - .Sh > =* s O O t- 3 C5 . .tS if =30 CQ H« 3 820 DTVTSION OF WATKR RESOURCES >- < CQ U 1/) u z < OJ a; ■0 b 4-» ^ 'F w u a ^^ U OJ a CO S 3 Q ^_ 7 a) < < 8 "0 H .S 7; ■0 c w c s D J? a < ^ U '-5 5 z < CO in 3 H l/J 6 W S H N Z lU u !;< ?; <; t/i a: c u < c w ^ ^ a C/3 *-) z n H E < « UJ ^ H Z 00 *n -^fOlcOiOOll^CO-* oooooo oooco -^ u^oo X;o < lO ih- 1 lOC ■"If ■ •♦ 1 ''« c^ . "^ CO CO ■^r^^eor^oowso oooooo OcO-^eO '< CO O CO - cvi - 1 1 1 1 1 o< cc ^o Ob-'M 'OS 1 CD to oooooo ooitor^ CO o t^l^ C^ 1 ^H 11-1^ ooo ^ lO r* OS CO ^ t^^^ 1 ^ o QO Ol ' 1 O « »C OS OS :D iC-i o o" o ■s 1! a o iO ' iC a a O ICO 1 1 CD ' 'CO a 'o rH [Vh* _o Q CO 00 OS 1 1 1 1 1 OOOOOO O ir*«-« ■ r* M^ ^ 1 . . . 1 CD COOOOOO-* Ol 1 U3^H 1 "o ** CD ^ lO C^ OS CO IC 1 ■ i2 * »^ c3 a iO c ir^ iM leo ^ 1 ^ 'c 1 O "^" i o loooo OO 1 tT -^^CO 0« OS-^ ■ 1 c^ t^ coco ' t 'O ' io 1 OS 00 'CO 1 '^ ! 'M CD i-< »0 00U5000 O 1 iCOO 1 ■ 0 ' ■TT f— ' 1 1 1 1 1 1 M ^- OS C*3 C^ O t^ OOO -^^N 1 t (N 00 CDCO 04 CD C^ »« . 1 5^ i if ! 1 1 1 ij : i ; i 1 CO . 1 1 1 e Q^ ; Q ; [ c3 1 [ ; ; f o iilN & : ■■•S ' ' ■ ' £« & § > il i i i C e? > i"c ; 1 ; tt-9-i £ : > o 3 o eg <55 .s.ii=t:1| 5 5 2 a « -.-S CL,eL,OPQPQO(l< 2^ 5I cg6 ■2 pi ^-^62 •oa^.SrS" •"s 1 1 ) 3 »-9 •< VARIATION AND CONTROL OF SALINITY 321 oooo ■^ lO U3 -^ ^* ^N Oa m :o CO CI . . . . . . < I I ■ lO oo CO en oooo t--. O kC -^ c^ CI O lO O Ci CO CO iC CO oooooo r^ -^ cs ■^ to ^^ CO lo -^ O OS :0 ooo»o t>- ec o CO oooooo »C 00 CC CD t^ C^ CD CC lO C3 Ol CO OcDCi-— 'C^COUS*-**^'^- CO ^ i !o 1 I I OOOOOO oo -^ CS t^ irt CO cOiO -* CO 00 CD ^3 Oimtym o coco OiOCO eo*-H oooooo CO t-- CJ CO lO CO CO CO "5 ^- Oi CO « " " C3 j5 o. a -sag o c4 ^ o c 5-g :s c . s « SSoJ.S.S-l a a- 1 '^ CD o o m o 2 2S OOOtO CC t* QO 50 ^H OS ;C "^ o :D osoo ;Dt^ 05 Ci O Csl U5 .-< e o PL, , _ '.2 I S i- 3 a ..-S iCLiCwecoa, _> K o c a> E a a>2 a a 5 — .2 £ 60 jj : ; ;K-C C M ■5 a j.2-s^ 'mP-' i»33 -> = s ?a a 5 cj CS 300 -I 1 •a a '■•3 i-a o 09 ec s CO . a, •g ° •2 «:o -s— c t*-^ s. "Se « g3j.5.=-i; - 3 J O a 21—80995 322 DIVISION OF WATER RESOURCES >-' <: OQ o o u Z Z M! W 1- o: ii u a Or M S s Q 1*^ i < C •0 H U Q Z C CO u c d 13 4J 3 1 a ^ ro < m ■>, W •-> ^ ^ H w u 6 H ^ N V V UJ r, ^J •< c CO ^ ^ to CO Z w n H E < > b; w ^ r^ lO cx> oooooo ic -H oo lo CO r^ CO COC4 05 oocc O I-- ^ -^ 00 ooo so OiOO ■^ C^ CO C4 00>nooco oo OS :0 "^O CO oooooo C7i :r? r- oo lo 00 »C CO C^) 00 t— c-i '-H « lO CO oooooo oo Oi O O OS O •CO CO ^-O o t* ■^ OOOOOO 4/3 _» to ^- >— ' OS r* -^ CO <— ' 00 CO oooooo »C OS OS to CO *x> CO CO CO OS 00 -^ oo o oooo O 00 oo OS CO OS CO t^ TT CS CO O CO CO s en to es -^ <^ .2 s =(£o -■Bf. £f mnocu V •a :^§ss^a3 rr- rt rt d C ^* C C3 BSSS s o ci a : ojco OS • feCO CJ JS CO, o c9 rt 4 '<*' c^ ■X! o COM (>3 03CCCI O Ol Ic5 lOl . *-4 o mm^ .W 1 1 CO ■ . O O O O (M C^iM ^ -^ t— * ^ W5 CO cs h- cs CJ ,-t Ml 1 lira 1 1 1 1 1 1 1 I o ... 1 l|p§ O^CO'' lOfOO C^10:0'0i' 00000:0 CO II -- cs ^ 1 1 CTlOOOOi/SO-* ' 1 ■ 1 U^^^OOOiO^ 1^00 -^ O ■ c^ oo 1 llii is CS..J.CO ' ' eo :o cj csooo I—- 1 OOOOOC30 o^ II ^ cs^ 1^1 r-csoOMioco I 1 1 IC ^ 00 t^co cscscs -ra -- « oo 1 N cDt^oo — c-] CTcooo es-*-^oo>o OOOOOO CO lO -H ^ « ^ .-^ o cs in »o -^ r^coi^ C.J t^ CD »o CO ' o ' ^ !* 11.11 1 . . o OO !cOO M '(N OOOSN San Francisco, San Pablo and Suisun Bays Pniiit Orient . _ _ Point Davis _ Crockett > Riills Hfiad Pnint _ _ Bay Point 0. and A. Ferry Pittsbure-_ _ ... Sacramento River Delta Collinsville Emmaton Three Mile Slough Bridge Rio Vista Bridge Isleton Bridge Mokelumne River Delta Southwest Point. Staten Island Camp 33, Staten Island Camp 29, Staten Island San Joaquin River Delta Antioch _ Jcr.^ey Webb Pump Holland Pump Rindee Pumn _ Palm Tract San Francisco, San Pablo and Suisun Bays Point Orient .2 s Q C '_3 £ O X '• > ; fc .= < 2 1 Sacramento River Delta Collinsville Emmaton Three M ile Slouch Bridce ^ • Q > ' %' I h < 1 ■-5 1 3 a, 1 i B a > c 1 o O S, C9 -SSo *i o aJ g = s •** 1^ oi • o a ■^ « a c >.& ■8-ga °J? >. .2 o-S » £ 5 I 324 DIVISION OF WATER RESOURCES ff> (S »> '-* >^ < OQ U v> HH U z ■J u CO S* « S j: Q *— 'i i < C •0 H Q 7, c CO g tJ \ a (fl CO < >, U •-> i CO 3 ^ C N CO (A) W5 -^ -^00 O O O O O ^ IM 50 f CO C^ ^ t^ C-1 (O o o to ^ O OO <* :© >-« 00-^ or* OO OO 0«3 c-i ^ Tf :o o t-* CO '-' OS CO lO oooo CO U5 CO c^ »0 00 CI ^ O O O O O « l^ to lO -^J* to OS lO »0 O O OS lO '-' COM* o o oo to OlCO cs CO OS r^ O «-^ CO t-- lO CO c^ Q oooo 0s c eg ; c a am cc EC 5" 11 "CO ^ Point- erry'. c S Jersey San Francisco, Suisun Pr^inf Oripnt Point, erry.. ■(1 i c 11 ' z Bay Point 0. and A. F Pittsburg:. o — c c c c . £ 1 -> ; c Crockett'.. Bulls Head Bay Point- 0. and A. F Pittsburg'. ■"li C9 3 a VARIATION AND CONTROL OF SALINITY 325 CO -^ »— ' i« U3 ■^ cot- d f-H OOOO ' ■^ ^ i-H CM CC i«iO ^H OOOO Oi^OOO i-Ti 1-- ^r Oi r-^ OO t- CO ^co OOO cO-^ OOOOOOO lo ■rr/o as w3 OOOOi 00 cooo 00 '^ i-l OO *f5 05 OOO 'ft* ■^•~< OOCO--" OOO t^05 !0 »ft Oi O OO OO -^ OO r- (M t-- O i— 1— < •^ 00 t— to CO OO OO"* 00 C^ O l^ »o •-« OOOOOOO lO CD C*5 OS t-H CO CD l>- ■^ •-< I OO oco - 00-* OS CM ' CD t- W oo •«*< o WOOD OOOO ^ lO lO 00 CD •-• OOOO ■^ rj* CD C OOO OO WOO OS CO lO f— ' OS C- 1— coc^ OOOOO^OO CD <-« CD CO t— CO CO 00t^*0 i-* OO ^ OS OO : es 3 CD : a ' S '• > a : □ : ^ o \ > ; '£ ; ^ c t> ^ > c £ ; E • § ;^ cc a c < on.. an J 1 as (sca .2 3 SO) Is u ■ ai-z -■CQ ■ ■— OP s -- ■ a o 0-. C3 ..-= paop-. c 5Q-SW 5 O t- 3 nPnOPa • S 3 -oS «»- ■~ i U ■-> .J e/5 3 (/I 3 O C n H N 7, U U fTl ^ u. < J b: r u <: c « ^ a c« 4-1 Z tf) n E < (D > CC U ^ < ■s 1 o o" o o. a> c 'n _o o 'o .S i c CO a o s >> a o CO u? ooco cc lO -Tt* <«« CC^ M ^ •^ -^r 1^ lO i •-« ' O! oo ' t-- CO ■^*o 00 lO •*•* e^ (M CI (^ to c^ i ;• O OO lO e c c t > 1- > 1 'Z X "• c c 1 't •r c b c a: 1- > H 4. a c C c -2: z c 1 > t 1 1 4 c c c c c «- a > s -s o 1 £ c a c 1 1 1 c 'S E- 1 -*- c 1 c B C *0 is i b C a C c 'S 5 c b c c c c a C Blakes Landing, Venice Island Ward Landing HnllaiiH Piimn ■.si V c ss 'J ■a c 1 2 ( s 11 1 c r > 1 >_ VARIATION AND CONTROL OP SALINITY 327 OOOOOO ■ i-^^DOi <— < t-^ 40 -^ r- r^ < I lo OS o> ooooooo ■^ -^ lO -^ ^- lO »o 40 O O 05 o to c^ 00 t»OOOOOOOiCO»C oco«— '-^tot^w^ootoooi^^ lO 05 00 ^- O t— iC ^^ 1— ' 00 to :0 O 03 OO CO ^tff oooor^ooo OiCOOOiOOCC^H O OS ^ M CJ OO ^-co COO ooo eoc,— T?"? 5| ocfl oooo g :m ; ^ z" >- i» «S /-s rt c c t. c. a a^ a S^ £ g B & E c3 >» oJ ca « fi^ C3 OHOOOZO J _ a a E E 00 5« > o ♦^ c E cs In 1.0 328 DIVISION Ol'^ WATER RESOURCES 9- r* o^ ^^ >-' <: DQ u (A t— 1 U 4) 3 .31 w 1) a; u (X to S Q >». Z < 0) T3 < H z c 3 .s C d T3 C c 3 O U s ^ CD \u >-i ^ a 5 '^ 3 H w u h H r^ Z CLJ u ,01 < u < en to O < > M CO oa O H z C CO C/) o o' o .s -9 ^iCOi^^T»«T|<-^iCCO^C^CO iO>«;©^cc'<»«Tt*^:O^Triccc — i-^ -- 1^ oi CO C^co-^M :ooooit*or-^M cc»«coc*i c^oo>u5t*!D'X>cocoo*ft'-»aseceo»ooi>t^ CO CO CO CO 93 CO ^ 00 ^ TPco-^co^ca-^-^c^ CO r^ r* ^ W5 CO CO CO l>- CO W CO t^ On > mcoco-^ M E -5 es CO "-St-? ' c h u ^ c! Gj _aj — o^S CO CO C*3 CO CO lOlOC^N^ bD ;2 2 o^ :5; CO . a S §B ^o w M 9 _ c3 =: ti s ff -— I 3 ScS VARIATIOX AND CONTROL OF SALINITY 329 ■ iC^iCiOTj«cO"^C^ OOO 'OOOOOOC) oooor oocooo C4 c^ ^ ^ OOO C^ C^) --D O CO -N oooooooo COOOiM^O-^C^CO :o 00 r- s*5 coco CO C^ CO CO C^< ^^ ^H OOO O 0'COt>-l^OOO lOOO « CO Cs» (M W -^ C^ 1-i M oooooooo 00CD?DTf«00«O03O t— coOtorrost-^!© OOO coeo^H ooost^cot^^tot^ csi^'^r-'l CO OOOOOOO ooooo tfoo-^ooosmcotot^QOOio OeO< : .3 CJ t ^ a is e Ma, JO OS .s ^ = c— ^I'n " i: •■' :^ O C3 o «- = == =._• =_••- oSkhss H " 5 ■ 5-0 2 330 DIVISION OF WATER RESOURCES .s 9^ < CO o u O 0. H U Q Z < 6 H Z w ^ o <: w of z o H <: > u V) CQ o .J < 3 O D i: \ 5 I o tr, -J tt.S go E I. is o -- J3 i-« o -^ »o coo CO Tf O t^COM eoeoooococo vCQ o -S X a> o a (Ofcftira oco III M . M cm c c ,5.S c Ma a 1(3 S.2 ■ e = o ^-5-5 2^^ g£^ > e i VARIATION AND CONTROL OF SALINITY 331 ^*^^cc»ot^c^r>- w5'^r>-Ost* ooooooooooo ^^^^^^^* • • ♦ •^fOCOC^lOSOC^iO ^ CO t- oo « ooooooo c^ 00 1^ 00 r^ -^ Qo r-" -^ cc -^ ^' M O oooo c^ t— o cs oor^ ^ -^ O^OasOaOOOSQO'— 'CC'^fO'— 'M i«ooo »o ^ ooooooo -^ o o ^ c^ ^rw^ r* :c -^ »c »o ro ^- ooo r* to ^ iO(M OC^iO CO * * c^ * * :coo:ocooo:otcoo QO t-- OSC^ CO ooooooo C^l O OO -^ ■* O '<*' r- Tf CO -^ *o —' o oooo C>) O ^ tr^ t* r- :-> -^ cooacoosroMc^iOt^ osociio co ooco-^o-^^'-hio ^^^* « ^ ^ ^ l-s^ , t^ ^ ^ ,^ CO CD t^ 3; O OOOOOOOOOOO |--.iOtOiOCOC^^-OOCOt^--0 Cq 00 --^ CTi ^ ^ ^ J ^ -«)< -^ CO C'<»«r-^Hio:D'^ 000 C^ CO CO ooooooo QO 00 -^ ■^ -^ M 00 CO f— ' Oi t^ *C (-- ^ ^ O ^ 0(M iCro»J7'^'«*«cocO'«' 000 O !^ C^ r^ ^« m 00000000 C^OO-^"^— 'CiO -•fCO — t— •-OtO^J'CO ;0 3 ^^ t. fc. 3 ' C3 O) CJ o Q_0_QJ_0 b. — o CQ ^ •o-a-o •a ^ c . _ „ _ l!/i o c Z c = a iJ ^ E-? a SJ i* t) t> "T P2- — M3 — ® "2^ g-11^^ « S £5 5.-- o 5 r -^ -fcj -r" -tJ -*^ -*J * ^ cc J£ -- c^ c^ j3 a >- c o. a ■3 aji e e a S C3 >> rt C3 rt ccOHOOO „ c £ J) a a. i s osoo <" — (B M^ — -3 „ Q " a;yj c iL -r3 3. tn a:c 4) fc fc- 4C oSa^o a-a,oajoa3«xO«Oc- ^ :t ^ :3 *J I ^32 DIVISION OF WATICR RESOURCES < OD O U O w o: 1.^ u OJ Q. en s 8 x. Q u- < 4 < c "0 H 3 C Q ■0 c ca C 7, § iS 3 i < m « o u 1-1 w 3 (/I 3 1) p H < c CO Z o H > w CO CO o H Z CO a E a) s s <« § so 5 if 9> i VARIATION AND CONTROL OF SALINITY 333 d ^H^H r-4* »o^^:oif5-,c^o t- lO »ccc r* 00 ooooooo lO -^ cr- 00 o -Trc0'^co»O'^^ iO»« OC^ iC OOOOOOOOOOOO '-■icootf5C50o^-C'^r~^r»co oo*cco»C'^C'i^-oof-oor*»o ■^ »CC^C• O CO c^ r* OOOOOOO CO 00 -^ — ■ '-• t>- o r- lO ■^ »o »c CO •— ' OOOO ■^ »C iC t^ r- oo t- lO »C"*COCO«3COC^l^ iC m OS O b- OOOOOO t'- CI Qi 05 C^ -^ r* lO CO ^" »o CO OOOO '^r ■<»• ^ CO r- 00 r* »o as i£ - a oj o o o-a i: i.>.>:s;o-c g g:Hr2 3 o e;^ c -I EC 0) a1 ^.2 >;^ 3-Ot3 : c B "« "x *w s o 3 O 1^ c:^— o 3 ' - ."T kt ^ "^ "^ c; •■'= S =• o £.= = Si c Q _ c :§ ■'is 1 "-a -J V 6a.s c a 5 E cr o Ox _ , -fc. fecQ »- 3 a Q. • S . . — osaaacccSocH 0= i^'C "' I 3:34 DIVISION' OK NVATKR RKSOrRCES •o 3 C n Hi < < BQ o u CO u z < u. z < w b; u 0. 3 Q i: c3 § V 01 < X ZJ < c H ^ C UJ Q t» r Z r^ D 3 a fj ■< CO I O H Z u <: q: u < z o H < > u CQ O < ooootoeoco TT O ■* C^ -^ CC t^ CO cc ^^ mc4 ^^ ^ o oo o-^ r*-^ Oi ic oo ^ M # • ic re c^ —* * 5 CO O o o r^ i'- iC to (O I— < ♦ t£). ' bC coeccicoc^ CO CO CO CO > t OS K t . = L'r75 ^2 c^ §03^- " COC.S .'-- Mt «,§ 5^|c O O tA CO d ;c 1^ CO ■* M — •; OOOCOC*50CSOSC^C^^^C«»0 Ol CC t*3 r* CC I® CJ ^ M C^ •— OOQOOOOOCO-"*'— — C^'^C^JCl^ •«»« CO •— » # « ♦ • * # • ooooocs-'rcocooooooooi iC ^ c^ '^ I c3 •-" S ^ — C *- i_ 1-3 CQ a Q sag I 2"a te u :« .2i-S||l|l-s:^-iS£ii dg'a .5.5 wai 3c3 a'^1.5 S(Sf^_- = o 3-J-J rt^-S= a s £ s « » s S.™^ "^.S a o VARIATION AND CONTROL OF SALINITY 335 Ol ?D t~— 03 iC t^ ecco^«040tD»ooo oooooo o I-* r- Ci lo CO ■^ C^ lOCO c^ oo OOIV* 00 iCi t^ C'lcocqcoiC^ocor^ ooooooo C^ OCC iO O Oi o ^- »o M T»* ■^ O 00 oooo iC CO c^ oo ■^ 00 to - ic t— lO ■^ *o ic »r3 lO-'^cot^-wscocor^ oooooo >— " to OO O Ci Oi ■^f CO »n Tf c^ oo ooo -^ !C IM lo -^ r- ooooooo rj* -^ 'X5 00 — ' r- OS r- Tf CO lo M" >— ' 00 oooo "* Oi t^ t^ lO - lO t^ o o »o o o o o t^ CO C^l OO ■— ' «3 ciO 1^ ■* o o :D >0 CO C'l O •— ' lO t— lO CO lO lO CO O OOO »o «-• C^ CD oooo CO CO 1— I CO lOOSCIC^lOCOOOsO * * * .-H SiOTfi»0^cD»OcD ******* lO ■* ^ oo oc OOOOOOO if5 •— ' CO <0 if3 CO r^ t~- »0 CO CD C^ C*1 05 oooo CD OC CO »0 CD t"- t^ -^ S,^-^ cS a-H «o- o. oa S » ** s « ^■?ga o - s S£ g o il.— o •a '^ '- bc I- ■T3-0-0 c c c — -^^ "w '^ 1« ■a c « O c bc I rt rt 03, m_:*fe •j'H. a^:|a C.J3 ,=? o -- -z c: jz n ^ -^ -~^ ^*j -*^ *^ en *j CC ji2 ^^ ^^ ^^ ^ ^' a^ a a a & a rt >» rt C3 rt « ff3 OHOOOZO ^ si «Q"" Q u 2 c 5 ■i : a ^ . ■= a e _ a oco £gi - »n'rt «-r ^ c 2P« =" S- 2 a5 S-T3 c (S ^iglli oSasSu ►J J) SO 0) oa.s "o'ojs c ^ fl* ?; . E . ♦^ 3 S &.CHOaiOcQP3coOiOeL. 83() DIVISIOX OF WATER RESOURCES CO O o CO o z < Oi «5 < a: u < CO Z o H < > a: H Z CO OS i: U) (S ^ r> s 1 Q *« ^ CO < c •0 H 3 C z •a c 03 3 1 O K M fO a u ■-> •< CO 3 3 H w tu 6 H H N Z «> M .« o § o o o a: a , 'S 1 c o • a •o >> C5 Q o CO : ; I I ; _. ■2-ZZ'S'^ ;2S3a •— 1 ■ • s i i i i i i i i ; ; i ; ; i ; ; ; ^1 o 1 SI"-;;* ; ;• • ;• s^t- ; : ;?r oosoJMooTfoJ loooio ^ .lit o ii 1 ;;;;;; ; CO 1,11. •^ o .OOM 'CO ■e^co- ;e«cq ou5ioe»— ;t~ 1 — »•«■ CO ■ , . . , e-1 — . ■ » CO ! ; ! ! ; I ; I ! ; ; ; I ; ; ; ; o 1 I ;;;;;;; ; f-t 1 1 1 CO . ' ' • 1 1 1 1 1 ■•o ooo.ococoN ;(NO) ;co ;e^cqe^ '.tn^- oom ;int^o ;« t^M 00eD00»O 11. .» ^H CO ic ■ c<^5^^ « eo 'C^wcq ■ w c? oioo^eooos .^coos —.C^J^^t •«< 1 tti 0O'^l--COC<||^ >cico^ '^ci'^ 1 eo «-• ^ Station Sacramento River Delta Collins ville Mayberry Emmaton Three Mile Slough Bridge Rio Vista Bridge Junction Point Liberty Ferry Steamboa t Slough Isleton Bridge Howard Ferry Sutter Slough Little Holland Ferry Ryde Paintersville Bridge Hood Ferry Frecport Ferry Sacramento -..._. cs C s > San Joaquin River Delta Antioch Curtis Landing Jersey Webb Point Webb Pump... Central Landing, Bouldin Island Ward Landing Holland Pump McDonald Pump o ;-S 1 :! ' 4i fi VARIATION AND CONTROL OF SALINITY 337 OC^lN ^ W5 Oooco * # COCOCOCO*CU5I^COOO OO CO iC oooo -«J« rr Oi QO U5 tcOCO COOrt* COC- to ?D O CO »0 cocc iC lO OS CO -* r* (N r* MCOCOCO^COCOt^ OO <:o ec OO •^ CO CO ■^ X> lO t— oooo r-eooo •«*< OOO -^ CO CCCONCOiOCOlOCD OOOOO OO t- CO ^- -*• CO »o r-- l^ CO »0 -^ OO "*?■ CO . a a § a CL, .(1, S^ S « 9 2 a:i_ •o 2 a t. t. 3 Q Ph H :/) fc D.^ 5 j;?= o — -a o 3 « o c C c e o bf a aj oj aj Qj aj "U a) -*j -rj *^ -*^ ■'^ Cm *-* a i. a & a'^ d. a^ a a a & a ca >> cs cs ca ^ o! OE-OOOZO 3ffl " n a c'-' S.2 -2 — =a — fl Q ° oSpq Q M > f— I -o o. So n c •ig;; lo a)" be >.:2 OQ o o 3 a _• e • -Ji 22—80995 § 338 DIVISIOX OF WATER RESOURCES < DQ O U u « -2 _ X Z 1^ 3 O <; c •0 H i) J •0 3 c a 4-> 7, c u hH u T 1 a O « < PO u "-> ^ ^ 1 a 3 c/) D o r. H M z U u C3 ^ < :j a r u • a u C/) CQ JH H HH Z H- 1 ^ W c. g '5 -* I I 5 »rt O »0 CC C'J U5 »f3 iC lO •— < .— t O CJi IM M C^l (M O >0 C^ C^? C^l W5 •^ O ^ '-' i— < O CD CO 0» Oa to 00 CO 00 Ci or-cs c^c^ •-< 0 c^ cc c^ Ol ■»*< lO IM (M CCM CQ «2 C C" >. ■ S b 5;:: cfeC c a? o 1^ > '£ c eq c* (N — OS Ci CO o^ ^* ' ;; .5 c M a 03 Oh g a o-o c s a 5 CO 3 O '1° CO B *^ Q a la "to . c c E.E 5 c' tj r: ti 2 • .5 £'2 c'S5q S.S a Is"". g-3 a 2 S S e Q Q " 2 S •-V VARIATION AND CONTROL OF SALINITY 339 OO 1 O ^ ^ CO 'O "i* coco • "Xsc^ cq CO ' --t COOO ilO ' O * C^CO 1 CO » • ■•-> CO.-. . — .-. •* to 'co (M ■ ' ^H 1 00 t- 1 1^ 00 ' 00 I 1 I * 11 iO 1 CO :" I I : OO iMOO-^CO'^r 1 CI --H03 --'-—( ..— 1-1 lOiO'^-^ CO O 1 t^ Cft'— i * C^J . 1 'OS CO 1 1 1 c^ 1 1 CO 1 , 1 rt 1 1 1 lOOOO 'CD ' '-' C^ 1 i(M II (M 1 1 10 ■* "^ CO * * 1 1 1 M ' 1 1 O 1 1 O (M ^ O O O OOCMiftMr-icO'-H'-" in Uti CS1_ 1 00 lO '-■ ■* ^ 1 C^t-OC^ ' ICO <»OO»OOOi00 1 1 1 IcO 1 1 1 1 1 1 ,-) 1 1 1 . ' ' »0 ' ut) CO , lOOO ' i .-^J^fMOOCO 1 05 lO O CO CO(MW3 '-t ' "-H 1 i-H i-H r-i i -*f t i-H ■ •-• » C^l ; :' i i i i ; i i CO 1,700 1,280 700 195 110 c3s Jl Drainage Water in Delta Islands Jersey Drain Grand Island Drain, Steamboat Slough Camp 35, Staten Island Drain McDonald Drain Bacon Island Drain Mandeville Drain Camp 11, Staten Island Drain ^ s ■a B c o c« — ■— rt 00 xi O en « 2 w ■o.i: D. '^ o> a aj ^ n « . P 3 tn CO a> a> - ss = c5-:3 .2o.g C *- C 5; g « 840 DIVISION OP WATER RESOURCES •0 u 3 C c o u U BQ < o < CQ O u U g - OT u Of Q ^ Z n! 3 J: 3 O s: < h u Q 3 o c o T) c to c o 3 O X! CO c CO I o H Z < u w Zin O a ^ i ^ 1/) 05 u BQ O >^ H z -H 1—00 CO CO "tOOO O O W3 >— < ift iC O c^ r^ c*5 OOOOiOCM Oi OiCO (M •— < ^CO CO i-H o OOOO lOCOOO lO r- r^ i^ t^ c^ ir^eo OOOOCOO o ^r^r* co-^ kO 00 CO C^ OOOOOOOCflO (M U3 ^*< «D r-H t>- C^ OO t-» (N ooo C^ «0 »-H OO O W3 1/5 Ci W3 «-• O O r* •-« « CO oo ■^ f-t £ CD C S* C9 0Q 8 1 £ g b. C c O ^ a (2 Ok 00 c « CO CQ =^^ i.a^ = « - ta c = -M -s S"-S »- o «« c« 3^ V ■*e<5(Meo 'M ■*(NIN-H PQ lO • .«, VARIATION AND CONTROL OF SALINITY 341 e< ea ec o W5 00 t^ O 0»0 O C^ "3 W5 O -^ ^O ■— 1 CO (M '-0 C^» »C O O "5 CO <-< to O OO C^ CM »-H O OCO CO OS ■^ OO ^* 1-^ Cl-<*< CQ CT> t— CO i-i CO CO CO t-^ CO COCO P«»« 1-1 0> OiiO »-l 1— I C^) -^ OO CO CO t^ ■<*< W Cfl -H OO f-i lO o - OO O O^OCO lO l-^ CO OO C5 CO COOO 2 'S — 0(/) ca 0»/3 eo -H** o CO 1-1 'S'o 3 O . S.*J CO a. , M a c «o ■ ■ »- o =^ rt ^^ « CQ Mo ,M': ' u O c rt 1^ (D ■oS OK H 0- »-3 J M !> CO ;U2 DIVISION OF wati:r resources o < o o o a; a, IE D := T) < s u 3 .s ■u c c 7, c o (i^ 3 1 9* o M < fTl V, Ui •-> < CO a 3 (U P I. H Z u <: c CO " Z(rt -> "i^ 2 "s- P I 5 1/5 a: w CO oa o H CO OiOeOMOiO'^'* 5 o > CO to 00 ooo CO I'. CO CO "^O CO 00 ^ s:; o — eooo oous ^^dlO 00 — o 05« r^ -*0 o ^ M I>- eo»ot^ccoccmiocot^:oo5 ^^ f-* o o»o — rr t-i OOt^t^OJIMMOUS t = te n bo 2 "S Q CM e:2 0) O) ►- — ' c ■a >i'a S « c o £ S T3 C In too »-■ OOtT ^ ooo oo r* -^ oco ■-< WICO c c3: C-o D. 2 i s « e f c S* 8 » .2 a 0(/J CLiii^n ,■■3 •So gS 1 VARIATION AND CONTROL OF SALINITY 343 oo 00 t^ *a to -H o iOi-t ^ £ o p w ^-O ' a; V 03 . 5 .-s t- b 3 « f « ; ooa fc £ ° bt b£ O. ^ <-i:f- m = 60 ajr-j O i? O -a " s fc H 2i o £; o o « k to g,2'35 csQ c ■a >'T3 C a> c Q -o a c.S ® a ten c s & ° — fi Q oS '■a ' s _^ a Q ZS -aS S 5 «^ c-o a § § S caSo 844 DIVISION OF WATER RESOURCES Cfl u •0 < S 0) 3 C .J a to C 7, c u 3 3 1 0- r? < n\ u >-> ■rt' z a 3 '/I 3 H l/J u 6 L H N 7. U u !^ ^ u < :3 a r u < c OT ^ ^ CO V) 4-1 Z « o n. H E < rn > m s CO I- a o o o oo — '00 oo ^r ooo ^< TT C4 c»•(>) — M c es esoa S CO .2 5 1*. « g eg •C"3 s o xa «s Q. C9 oa cocici c^eccc CO c« c^ c^i CJ — -H o -2 c^s_cQno»cu Q. oa S OS g 4) . «« fc £ O = a S-* fe^ S a > £ c :" s = 3 VARIATION AND CONTROL OF SALINITY 345 ^HCOOOCD . ^W-^^H •^ !£) »0 C^ ■-< ■^ U5 Oi r- ^H • oo OiOO O 'O iC C^ Pfl c« w c^ » C^ ' «— ' • # * » * \0 ' "5 » h» ^^ CO r- ■— ' -» « TfQOOieo Oi ■ ' 05(MCO OOtft 11 C^ lO CO 05Tf * oo 00 oo 00 oo O wO — <-HCO ■^ CO « cq «<« •-< « 1 . Oi-h* ir^ur --^ w -^ * loiooo ■ 0000 " : i i i i i i i i i i i i i • i * i i i^ i I i i '■a ■^»o ' ■* c^ o> eo pj t^ 05 . a 9- rsocSKKw O J- O C3 ^ w- -ic to E3 o C So 0000 00O5 — o 5 = 1 eO'O £5 «^-? = Q " ►-5 E 6 oSmSo -2 q Q o £ rrj c „ o S OQ o o S.5 K o 3 CS can o VARIATION AND CONTROL OF SALINITY 347 iCC'J O tOOOOOO ■«1* 1 OO to TT - 1-H h* W^ '-« c— «-H * « * « « oooooot^o C^t-C^OO'^'-'CO OOiOOOit-O'-it— r^CDiC«OCOt^»OcD?OOit^OOCO i-* OS "^ O 00«D M oooo O 05 t— Oi ocoo »O00O 05 -^ iC ■^ C^ CO r-t 05 CD «0 m COOO ■^ t-co ^ ooo Oi CD -^ oooo :d oo ■«p o CO TT CO C^ C^ ■«-< CO -* •* -^ « CO t^ «o CO CO CD CO c^ *-i r- oo oo OOa ocoo »r5 * CD Oi ^ ^ CO »^ t^ oo o c^ oas ^* CO CO ^* CO i-H lO OiCMO oooo CO 00 CO 05 OS Oi lO t^ OCO o CO C^ CD Tt< CO (N C<) C^ (M 1-1 lOic^iocor-ooo »o -^ t-t r- CD 00 CO m £ CO 5 £; S la d5S m C3 Q 3 > c: E , 2 ^ "^ i'lis'i s. « 03 3 — -i'i'S-S S"-" , Ma, c 3 M ' 1 t- (-1 S? -^ fc- r- C3 w oa = ! M ;^ s-c;s s a «,<;^ .2 S'S^i-S^-o'^-^'P-S ■£g-5|gj5-3ls|£| SO) w _ M E3 " a- a "a bt Q T3 a c. £ « OS T3 C .2 -SoQ ■ 2.H a iQ go; ■■T3Q5 Oca u S C3 asSo 348 DIVISION OF WATER RESOURCES I o < DQ O U V) ^^ O < Z o H > an O H Z BO 3 o X Q i: CO <: § Tl c 1 u z c s 3 1 a r^ < Tl o U >— 1 — z < 3 3 H 1/J u 6 n H N z OtO Oa4 05 -- O 00 Ci C^l 00 o»coooo C-I TT lO CD CC ^S* ^ O OSOO t-- OOOOOO I- lO ^r »o •— ' o ^ O OOOO I^ i s u, i- J3 ■ Oi ^ 0000-^ OOOOOO ^H lO 00 M' 00 '^ t^ oooo O f^-^ •* in -^f (M CO oo t^ ooco t^ OOOOOOO oo I— " oo lO »o o -^ ■x> lO CM oo r- r>- lo ooo 00 00 lO •^ ^J4 C^ OOOOOO CO CT> so iC O »0 CO CO i-- oi oo yis ooo OOOO ■-^ c^j ;o -^ <-« oo o CD ^r i-i oo CO W3 "^ oo f— CO lO o i-H O o oo O lO o oo Tp OS C>1 .a 3 o CO C3 Si' « ja 3 w J- O rt if 5-3 C fc M E.£-£i2S a c?C;HZ Q- I C3 dm c S a> cs — = _ 2 a) c Q 2 S 5 iM 15 C3 5 q3 5Q 2 « a- J3>2 « bocc c 2 a ° — s Q .T3 5^ cm bO O O 3 rt ■ c; ■ — p, d, CQ CQ .5 a. PQ o r.2io ■' - Co" t- o fa 0:^> t£ o J^SdS ^ ;^r)0 DIVISION' OF WATKU RESOl'RCES s ^- « 'rf <© ^- C^ i-« »-" ^^ -i^ «-^ --» i-< OS CC ^ • • • • r^ '^ -vf ^ OQOOSC-IO'^OCO- ^ ,_ ^M « * o»o^oooc«jo>^^c^o>ooo»ftr»-oo»C50io^ CC I— « * # » » • •o CD Q i= T3 H •S Q S § " I S* -2 f? < CO c o ■o c CO c o CO o a >. Q W3 C<1 t-- oi c^ r>- ^ 00 o -^ 'O o 1^ c^ r^ cc C^ 0> ■^ CO —< >— ' ■^« * # • 0(M i:C ^ « * * »r5 lO '•r to — ' i^ c^ c^ C*5 » » s CO osoo r^l>. ^£^ »c ^ ^^ If:; »o « -^ a . ; 3 So ■ ■ ' ; • = ' ' — "O -S .' 0)' o) ' 5 o : ««(£ fc3 £ o -I g-2 c-Ba-; ^ rt „:--2 i? = 3 E ;Ei.2=:2^^§ 00 C^ 00 <^ 1^ OS -^ .S ?" t>i O. 3 -; so CO «5 t^ -^ a^Cu Cf on. •— ' >> c o fc- , ,_ w S w 2 o £ o c5 mQmS tie c c ^- c t ep E c: « 4JT3 s o U3 P 3 O 20 VARIATION AND CONTROL OF SALINITY 351 O ' oooo »o ' TT I'- tr; o h- 1 .— ' t^ lO t>- oo lo r* 00 »o M* o I— -r « 1-1 ooooooo 00 CO -^ CO ■^ CO CO CO ■^ c^ as lo :d CO oooo O r* to r-- CO ^ OJ ;0 »0»or>»cO?D--OcoiOl~^-H CO ^ OOOO CO IM Ol OS t- :0 cq 03 ooo ■^CO 05 iC (M «3 lO O -^ -^ CO CO CO <£> OO CO CO * O O OO I— o ■^ o -^ O o I~» — ■ r- ic CO oi t^ t— "^ ooooooooo Ol'^O'-HOlC^'— o»o toiraco'-o-^co-^oo-^ OO O-^ 00 :00 OO coco CO •-" c^ CM <-H # oooooo OiO r- ■^ Tf o CO »0 ■-' OS O CO ooo OO oco iC ^ CO OOOOiC-'J^T^TfCO lO O t-- .— I # Tji CM OOOOOOO OO :0 C^ CO "^ Oi OO I^ i« CO O XI t^ ■^ OOOO 1— ' CO TT »-H CO XJCOlO OOOC»t--iOU5:OcO lO »0 lO i-< lO iM i-< OOOOOO lO to OO lO Oi OO I>- Tt< CO O XI t^ '^CO . O X! lO O O X> h- r- If O C'l r— • ^ O O ^ lO CM O 50 I CO —i .-1 CM O ) M ' o .CC CO c ■ S I I- IT3 OIJ '5 5t''2 D.° gT3 C. oi2i|i|i cs CS Q. CO 5« O 3 a 2 S-S-^ 1. '7- rt ^ m o •o'o = « . s.- Sh &■ oa ra o h^ Ell OQ v S £ '.So 0) to C3 o c o E 2. £• t* > 2>h::SoSZh, •i rt o ^ ^ o >. , i£>--gblj2 a o a _> C co-r: Its s »— t a is "3 o n _2 ■ ^ .= M a S 5'-i^3^i — =-) _ "-a 5 > 55-T3 M O." o " «.r £ 352 DIVISinX OF WATFU RESOITRCES < CQ O U W l-H U z < a, u. z < u a. D Q Z < > a. u CQ O > _1 < C/3 < c ■0 H u 3 C u Q ^ ra c 7 c d 3 1 C H ro < CO o >. U —l < z < (0 3 3 6 I. o H N 7 ?^ Ul CO ? b. < J a. r u < c w j£ ^ to c« ^ z ?i r, H E < J^ o iS es a o o cc ^ ro ^ M tooo -woo ooo C^ CO oo »« C^ OS oo — 00 CO -^ oooo ooo 00 40 »o »o -^ oo ec lO c^ o ^ c-* -^ -^ 5C -^ '^rco — — csrN, oo cqto * r- »C ^« ^co^ -^oo t>- I- t— t— -^ lO iC Tf ^H o o I 5 3.SQ ■? -c^ aa 9 oO — ■— *- *^** :^ la 5 C3 >> « c Sue Q 2 £ ooooo •i c» -^ O CO -J CO Ci r>- CO OOOOkCOO c^ 00 OO '^r O c^ t— »c CO en t* CO iC ^- OOOO c^ iO -«r M <-tiO CO "3 OOOOOO CO CO O ^- *C CO t^ 4^ .1* r^ CO ^ -i ' c Q C c ed 09 eOflQ .-o 2 H - a 25 -oa.« !2J3 = (1>.-X i- '», oaa3-5^;2j o o = a . 2 .t; c-cpapao^fx I VARIATION AND CONTROIj OF SALINITY 353 oooooo lO «00 CO O t^ oo iO QO 00 lO oooo -* oo CD OO 00-* ^ (^^cc o OOCflCO^JUDC— < O CO >— ' O lO C^ C— ' O C^ lO O c^ rr m C^ »0 ^ C -^ ■£ o -X a is o a^v > 2° ^ ■ -, s g osO ■3 n^ as ■a o O >> u c o- Q3 CQ 5 S fl^ "^ X r" « '^cg ffl =- .-^ T) ea 23—80995 354 DIVISION OF WATER RESOURCES &0 o: 4J u to a w S 3 Q w. 1 CO X. 1 < c o T3 H 1 Q c CO C 7. c d 3 i-i 3 1 9* O rn < nl o >, U •-> hJ ,_^ CO CQ 5 i < "? 3 c o H N 7, o u .n) < u < CO Z o H <: > u CO oa o H Z ►-I CO 1 r^ •00 . ooo ^^ c oo oo O 1 O to « lO 1 'O 1 (N t 1 1 ; : : : i i : : ; ' ; i o< ' cow M i^oo OOOOiOW3»0 oooo lo 'oo oe^m 1 ^ r^c^coeooo t^ ■^ CO 00 h* 1 C» . -^ r* CO CO kOC^OO too) -^ ^—00 CO ;0_ it>-^ C^l ^ -N • ; \ 1^ !^ 1 ■* - M > u^ iC^OO o o o o o uo 1 oo I looooo OCM •«• I CO — t^ lO CO^^ ■ cj r>- 1 1 CO »c cc CO o 00 C>* CO C^l^ C» lO C'J -^ ' •^•^ ' '0_00t^*0 (M 1 hi I • 1 , , , , , , 1 t 1 1 I 1 I I lit' » m I 1 1 1 1 ■ 1 1 \ \ \\ <*.■ O , , , , , . ! \k o (M 1 1 1 1 1 1 1 t 1 1 ' ' n 42 ; ; ' I I I 1 I 1 ' : I p c. 1 en 1 s or- 00 CO cc o oo O wti o o oo 'ooo I !o OrfPI 1 o c o i I "C >> Q o ' O' I>- CO OS -* OO O OOO ' o O . O ' O 1 O O O Ic9 1 PO cc O CO OiiO C» 1 C^ :0 -O t OS .CO-^ CO 'o ■<»« CO rcoo coc^ -<*« ' •^ -?< ■ t^ 'O 'r«-»o "^ .2 £ 1 < 1 > 1 I 1 c '" c^ 1 1 1, .i" !*: 1' 'S CO ' t^ C30 '^ cc t-^ O C^ O O O lO »c o I looo loo ococoeo C4 1 ^ 'V?') to CO t^ M oo < .oooco ' cc iC 00 o r- T^j^Cir- CO '^r -^ -«r 1 , t^ w -- . 00 »o — ' — .!-*'—-'. ■- >0 oooo 1 I ! 1 1 I 1 Mi 00 C4C^ 1 I 1 t t . • * I i I I 1 I : if I 1 1 • I 1 I"- 00 -f*^ --^ oo 40 ooo loo ' ooo I loo I c 3 I*H«-I C^ ' •*»■ 00 r^ 1 cooo ' r- O c^ ' 1 o lO ' 'fl r • *M CO * CO C^O 1 c^j -^ ■ TP CO — ^ ' ' ^^ ' ^ 3 ; 1 CD !:;;;::; '■•'•\ -^ I I I i ! I I I Ml oo • <3s r^ M t>»cc OOO 1 O O »J^ oooo loo 'c 5 C > Jec« C^ ' "^^^^c^ CO Ol oo ' ■'T I-- O O O 00 CO I crj '^r ' c 5 C (M • • CO ec c^ 1 re -* « t-'S cc O CO . O — ' 1 ' ^ ^ CO ij i 11,111, i ;;;;;; ; iiij c flS CO 1 4* 1 fl 1 ; ; c Q i i ;Q a 1 1 1 1 1 1 1 &:;;:;;:; i 5 iiii i ;^ (L c: ■§:::■§ San Francisco, San and Suisun Ba Point Orient Point Davis Bulls Head Point Bay Point 0. and k. Ferry Innisfail Ferry Pittsburf!' North of San PabI Grandview Sonoma Creek Bridge... Vallejo Lakcville McGill Cuttings Wharf. Merazo Napa 1 > c i 1 s Q >• ^'2 ■'-3 Camp 3.5, Staten Isla McDonald Drain Bacon Island Drain.. Mandcville Drain. .. Camp 11, Staten Isla ; £ c < o ; E ; Si 1 S,\ I I F.mmaton Three Mile Slough B Rio Vista BridoB.... .'-N .-s ,' 1 1 3 I1 1 i •S .] ^ 2o > m ( S^ * z: \ VARIATION AND CONTROL OF SALINITY r;p; ^-* '^ t^ lie 'Oas — 3iOl^ lOi ' '—• <50 oooooo CO r-- 00 "M •«»* ii5 lO M oi r- -^ ro ociiTicc^t-'C;— 'Oi-— 'oor^oi oo o o o ;o -^ cr> :0 --H GO — ' l-^CO C3 o oo o o o OS rr "M !C »0 lO lO ! C^l CO C^ Oi 'J CO ■* ^ O OOOOOO O O -^ i^ CO :0 Oi 00 CO C^ 35 lO •-* CO '-' 00 CO O I— C^ (M o crs O o C _o ^ C3 o 3 --^ *7 t* ^ B 6 ad 3 jr" «^ DC ^-22 a>'^^£ >. E n IK a-r: » 2-, ,-^ T3 K j^ a. L."^ c IS Q c » C3 s a .-c 3 a. o .S 'rt Q ■o c 03 C I'm 2 £*^ -cQ Jl J" a. » c ? U CO .2 = wo ' o . V c-5 c 8 p E 5 « S.= <:!r Ef o o 3 a . c ■ - ^ a 356 DIVISION OF WATER RESOURCES o < O o u "0 3 C *j c o J, (d 3 O X JC I c o T) c a ^^ ir^t* tco«oc50i iQoaaw t* CO 1-1 — ^ -(Jl »-« ^ COt^ a Zft. oS n r/:!'C.5 C <* >• : ««,£ S3 So '^.2 o >. c ti a s ■ A •-» ^-» l_ lO iC O* OS 1— ' g)0^*001 .S u> 3-J ^ 3 ^ rt Scri:) e 5&:m ■^ rs , g O^ Mg^ =30 rt.g * 5 I-pK "5 "i <^ Q VARIATION AND CONTROL OF SALINITY 357 00 OO 35 Cl 00 O O « c o ^ ~ 3 M ^ O OT3 « = =» = "3 ^ " S " 2S .— rt o ?: o o ■S-2 > 4S c c^ c t Si '^ J< ^ - - o 3 a) c; O ". j £ «K 5 : c 2.= c _ o '^ g-a c g = e c o. a o O a o (rt r/l a u — "t; y, s cu o o =3 ■i> n- ;3 c >* ft 0) C ^ ^ o *5 358 DIVISION OF WATER RESOURCES •< DO O O o "^ w fe Q <*. ^ to "0 < H _) U Q Z D c 0) 1 c d o 3 a f^ re CO >> U i-> , ) CO CO ^ 3 3 H Cfl u Q C ^2 c a E to a o o o o e '3 ooo ^- ci m -<*• ooo ooooo «C CO O ^ C5 CI 00 00 as cc O O O ID 1^ ic o OO ^ O M 00 1^ c^ CO 00 1^ CC CM ooooo io o m r- iO '-< C^ OO •— 00 •^C^iO OOOO^rOCiC'JCOOO O O •'T o —.CO >o C0t-^!:OC^^OOPOC10500>0 00 o o O O tCs »c CI 00 Oi OJ Oi -^ lO O t^ CC CO OOOO Oh-O O 'Xi CI Oi OO — ( C cc t^ 03 ^ O O O O -M O O ■^ »C >0 O-l iO -^ lO %0 Ol •— Oi <— ■ Tf OOOOOOO CO 'T OO OO O »0 OO C-l O C:^ CO OS 1— ' o CL OS C CO* CSOQ 08 "a *» ** 'A c: ., ^ .£.E= >.«'cS a, 0. BQ a o >^ CLi ea I CD n fl 2 Cc2 •r; rt- 5 O > Z e c CO r o o -as oacc — CD»/S-^OOCCOCICiOO!£S3a ^H 00:D;DCOOSt-»-"OU5 5 Q o > o. i a 3 csO t ,,, p r, ^ J Oh — -3 =^-^ = ^^ ;aj^ VARIATION AND CONTROL OF SALINITY 359 CO -^ -^ — ' CO * * oooooo O OO O O "-H Tt< CO t-- 40 CO '-' ooooooo oo '^^ 00 •— o t^ o Oi 00 :c ci -^ »c «D ooo (M .-• OO COOOC^ 3iOO OOO 05 C^l O CO c^ 1-1 OS x> ;o O CO :S fM 'M O Oi OOO CO tc o CO 1"^ y=> O O O O i-O CO o CO GO O O CO --0 O c; -J r- Ci -o CO •-I O l- o^-*cooioioco r-1 T-l ^H,-l l^ oo as 00 oo O O CO C-1 <-« OS o »o r-* Oi (^ I^ C^ O CD C5 1-- 00>OC^ OOOOO if2t-^_ -t^i-^COOO .— « C; iiO r- Ci ■»»* lO O C-1 O O 'M CO 3i OOO t^M QO ■***o iC OOOOO CO t>- 03 so fi; OS f- CD Ol Tj* M -^ lO -^ O O — ' Ol O ; a B J-i— I 1 k o o o to n o i« oo O — Ci t* ID O t^ "^ ^^ a i c° =-o a — d G O c e S §13 g « 5 cScaSo .Q » >« a o an CO c a 3 u OOO iC i?^ cs 05 :C! t^ (MeOCO-^OOO-M^ Ol > C/J ,~.S — o ' o o o " rf • . .„ Dh 2^ 3: ca o .^ CL, _ ^ O V I '"ill 3 ^ ■£ OKr/i c ;50 ^ — "O -* o a CQ fi c 5 W3_ cJi 20 -as? 2 5J Drai Jersey Grand Slou Camp McDo T3 e c ill !» 360 DIVISION OF WATER RESOURCES Oi , u •-1 BQ ^ n 3 (/) 3 H (/J u c o H N 7 U u a u < w CO z o H > a; u w OQ O H Z a E CO c/5 o O O ' CO ^ Orf O O O lO CO o o ■^oo o r* O «-< oooo-^ ^t< r-. 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S H >5J .0 „ o O -*. a r/; 3J~r3a, ca: 03 u 10 i?^ _ _ <-" a; o o oKSoskS-sx c-rr SQ 362 DIVISION OF WATER RESOURCES S < CQ O O a b CO Oi o < CO CO Z o > u) CO aa O >^ H ce^ vti w cd IX w s 3 Q < c •0 H 3 ■M Q 7, T3 C 03 u c o U 3 T 1 9* o < rl W '-> _) ,_^ n! ca 5 CO ^ CO 3 o C o H N 7; V u a a E w 1/) 1 C-I lO • , i'«l»^t< ^oooo»o < OO ooo CO O 1^ irSiO 'OiOiO • 1 -^r ...1-ieo C7V35— «--.oO' CMOO 00 « 'CO ■ 1 11!* CO -^i M OO :o to 1 '^^ 'C^I^OiO CM ^ ' o « rrr * ; • * 00 OJ ' ; ' ; 1 J J --I •O . .0»OCO 000C5000 OOOQOO '^ -rr C) O Cil- •O C^l ' «D CO to CI ii-i <«r 1^— .^otD»C^ • O CO 'C^ * CO CO -^ f^ r~- >o -^i c^ 'f CO O CJ 00 CT> CI ^ < » CM ' ' - - • * ■^ C^l OO -Oil-^'CMJOt^ OOOOOOO oooooo OO I'^'eo (M ,^HT-(^-^»i rroococo-^^o • O ''t" C-l 00 CI -^ ooo .^ C-I 1 • CO ■^' Cl l^ -^ *!' ^H ■^ct^io ^aio CM CM • CM r-T^— 7 fc- o; rt 1 II 1 • 1 1 1 < 1 1 , fr 'CO o o C0 -* CO ^ CO • > OS Oi C^l » o 1 1 "— T*^ * o" o ^ a *3 o ' lO Q. a to >* CJ .s o Q cc to . ^ — H CO c^ (O O O O to O 1 o I ' OO O IcOcO^ Tt- , ^ ^ ^ {.- (M ira f- CO o irj 1 t^ . 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S San Frai Point Oiien Point Davis BuUs Head Bay Point. C). and A. F Tnnisfail Fe Pittsburg'. akeville,- uttings W etaluma.. Sacra Collinsville. Mayberry. Emmaton. . Three Mile Rio Vista B Junction Po Liberty Fer O -/^ > -J o c- i-n 1 a> ^ ' -J ■^ , .^ c o ^ xd s- S VARIATION AND CONTROL OF SAIjINITV 363 oooooo ■^ -^ -J o oo oo (- ic « o --^ r- O0OC5O0 O ^ .-. -x; '^ ^r — '^ I— kO CO — ' r - I— ^»* CD C^ Oi »-H t-H C^ T »o o cj; . Tji c^j ■ -^ Ol 05 '-' -^ o o o c o o fM :c o ':^^ to O (— ■n"M oi iC r- oooooo o '-H o O OO Tt» ■^ c^ t^ »o CO Oi i-^ r^ -^ C'JZDCOOOt^COOOOl r— I-" o ^3' 00 OOOOOO ^r O 00 C^l CC TT I-- lO C^J Ci tC :D I -^r i— ' OS t-^ O OOOO o o *r oo CO oc -^ --c tc x> c^ o r- ^ ic CO OOOO 00 O O O o oo r^ "^o oo o oo o o ^ TT — • CC O ^ OO t^ ^ CI oo r— ic ^ <^' i a ■_ c o. c a"^ a : gi^a E-^S g a : a >. a a a a "-■ a )OHOCKCx:o Q 5 E S 1. Q CD >-i-^ 2 « ^ (SCO C CO 2 pi g-Q si I O 3 « ■= .2 5 c a,CL,33CSO£a- 364 DIVISION OF WATER RESOURCES 3 •S £ Z CD CQ <: H en 3 O X 5! X OJ C o •o c CO C o c3 3 ^ (0 z « [tj o <; c -' ^ ^ a c/3 " 2 a w CQ O M i£ •o i2 t- a o § o o kl s, -S o *o l» a *H CQ ■3 a o a >. a Q o s « o ■ »c »n •" -r -^ Q • 1^ »C oo ^ • tn ■o^«^«^*oa^•a>CMeo'^^ no 'OO t^ noo»eM.--H-» — « — -. it^ 1 .» ICM • • • • |> 1 00 : : ! : ^i 1 I I I I I I I I I I ! I ! I I I oo I CD . ^ .^^ J s; ! !io 1 i ' • o iC4 o cnoo > • CD 1 CI 33 CI m ,—• OOOOWVIM — 0 1 -^ . w ^» t^ !iM O-»00l»C^ i—KMI^NOO ! O SS OS • .* C^M^W-^rt ,rt„«„«_ ,oo. 1 .^C^CI* !•••#* Itt 1 » » 1 1 CO -r is ; 1 'tr 1 1 , o . rf» to -«J< (^ 1 . oo 'OO t^ CO o !i* o lOcoooocs >eo«o 'O .os^ -HI* •»> 105M — •♦ l(M-H^ l(M 1* —I «. CO' * l#* .#■» O lOOO ib*0> lOCl^OO itO^^A • 1* 00 1 — CM i» • iC^-H^» it--< CM l-H ■• • • 1 • 1 1*11 1 o 1 North of San Pablo Bay Grandview Sonoma Creek Bridae 3 ! 1 "S-S oo. Sacramento River Delta Ccllinsville Mayberry Emnuton , . . 8 ffi •3 9 O V. Pio Vista Bridge Junction Point Libertv Fcrr\- hlcton Bridge ..^... Sacramento San Joaquin River Delta Antioch... Curtis Landing Jersey Webb Pump.... Central Landing, Bouldin Island M andevillc Pump. Rindge Pump Middle River P. Mansion House Stockton Country Club Stockton Mossdale Highway Bridge Durham Ferry Bridge o a '.£ i-J VARIATION AND CONTROL OF SALINITY 365 OO t^oo ooooo ror^ o r^ Oi ci rr "^ t-- o oo ^ .CDc0500000013)OOOC CO oo O CO CO t^ OS lyD — ■ ^ ^ .-" * CD o o CO O •-' oo r- uD CDCS O CO Tl- ?o Ol 1— ■ Oi OOO CD CI r- lO iC CO o»c»oocTi — ricoooi tC'VCO'-^OOOCJi— ■» * CO £M ^ -^ ^ • OI>-tOcO»/5<:000 OOt>* oo 00 CO o o o CC 00 Oi o oo-o O — Ol o --D -O ^ Ol "OOO r^ Oi oi OOO I-- -rr r- r^ --C CO OO 00 oo »0 0ra u^ to CO O oooo 00 — • OS C I CI • t3 (3T3 !T3t3 c3 c3 E.e -^ S (3 a C3 V OJ (U fll ^ -*J -»J ■ -.— -, - -.— „^^ rt c3 I rt ^ S3 CO .—.^Ofc^uO^O a^ a 0-3)8 & c3rt>ic3c3c3r;aJc3 c F Li ' c c -a rt es (X. CO c 5 etioa 3 ° 3 J3 "i" K o2b3 as .£■5 c •- cs "0 PLC CO n So •^•f E ; a, a-, aa 23 c i Ph -^^ ;= >. fc- =3 =3 C; v:; > oS J-si ,2 o >. , __ _ o - 13 O; jc r s a d-c.?. --£— o^-i:^ >, i3 E- :^ »^ i-J -2 X ca; - c, "3 366 DIVISION OF WATER RESOURCES <: o o (A o £ r z M ■< X w V oi ^ u CO fr yl s 3 X Q ^ Z < CO CD T3 < h r c UJ CO Q y c n Z o tj *-< 3 1 C ^ 1^ < CO O >, w ►-» ^ CO d z 3 < < 3 H (/J ■u 6 C o H Z u < DC U < w' Z o > U W 03 o >" H Z 5 a E CO o o o o r^ to lO QO 00 '.O i^ O oo r>- -r CI — " — « CO -^ ooooo _ OCO Oi COOO <00 CT>OC t* ^ -1 O O O Ol CJ 'O O 00 c» 01 to »0 CO •— ■ 00 o x; CO — • O to O OO O ^^ CI 1-^ CO M« •O -^ fM •-< o o »o -ri to ^« ^ ci '^ CO »0 '«»' CO •— O O "5 IM OO c^ ■-»» x> o c-» »C •* CO •— O ^ C» ^»* OS Oi t^ '*' -^ > O tff — OO ^^-■^t— cot'-eo^co ico — ^- SCT^^'-^'^* o^ OcoOQOb*oo3'-«osr--. »c d as o ^ ^ "^ -^ c^ Oio^-^aj*oc^ooeo:D C003ScO'»'»CdeO«-«'M CO -^ ro lO to C) "^ »o i:C O ».T '•r C^ M (M ^ CJ c,i 03 '-0 ■ a as u. lo S'O ' CO oo oo o ■»*' to ;c (M rN 00 ct' -^ 1^ ■ O O CO CD to 35 CO tOCCMC^ o oooooo M* — ' a; "(t" oo CO CO 00 OO O lO CO CO ^ CO c*^ o o ooooo o- oo •* rr ai o — ' oo t-- :D ■<»' CO '<*' o oo ^ :o o o o o 00 00 oooo CO 3i ^^ iO OS r-- i>. »ra ' -^ O O CO o o c: I o y^ 04 o -H .-. CO -H — * oo O = to =3 tT -^ I-- o lO CO 04 04 ooo CO ^H r- 00 oo lO o^^r^otoioooooooco; (M Oi to '•- oo ^r 00 "M "M C^3 OI --' * a3i^o*ocoiO-^coo^o)oi— « oo o o O O QO Oi O O CO 00 ^ CO (M ^^ c-iOO 1:0 r^ — I 00 t^ ^o 000 OT y^ o CO Ol 1-1 00 0000:30i00 Oi -H t-- O O 01 ■^ — — - O 00 • t^ lO CO »o ^^ • * » tOiCOO~00000 CO CO CO O CO — ' ♦ C^l CI -M 04 '-■' * o o o o o tC o lO M O ^1 O M 00 O wi f^ to CO O-J ■— • .— « ic 00 ::5 00 000 00 t^ CO 00 »o ■'T O O — 'O CO CO »0 t-^ 00 1-- CO ■^ 00 •^ 00 ■^ CO o o o -^ c^ as 00 CO ■^1 00 "»r — « O O) -- —. »o o or- »0 04 000 C<| to --o 00 l>- --0 000 ■^ 00 rr C4 ^ O 00 (M 00 CO --c oo=:> o r- 00 -^ "^ 00 CO to ■«f 00 O O :m CO t^ 30 000 CDC4 — .-H r^ ,-« ,-t O O O lO CO T^ :D 00 -O — r^ rr oi — -^ CO A CQ C/3 _ >— 4 u (A E ^ ^ =*■ 3^ ^S= c3 -■wo ' c •- ^ c W 51 o rj r3 t- pi- *j 3^ o m .Sue. — ,2- — j"3 C 3 55 -2 S^'' o i 368 DIVISION OF WATER RESOURCES T3 V 3 C c u J. U .J U >~. O^^OOO-^fOOC^lO'^OOO^ -^ OOOCMOO^eOCMCMOC S : -^OOr^occc*4i^Coooof^coo^^•^c^ e '• '• OOCMOcCt^CM QO C3 •0 1 1 -"f CCCMCM^ ^ ^•< i C^ • ^ o »o o -M -^ o o -f -- -^ -^ a: o cr lOiOOu'^'-"---^'^^^ O x)i-«.X'aO"Ofooocoooc^-— 0— *O0vCr^CM» 00 CM (M CS| ,-1 ^^ ^ ^ « (Tl -H — ^ CM^ —» ^ » • (M * » » * » « I~. > o C^ « > • • • • CO ■<^ i_ c5 ■ a ■ OO rJ •* M ' < t* -OO-*** 0; =r »o QO ri ri CO -- cr: o 1 cc»o -H ir>o 1 ICC jcocq -* — ' X) »CM »^ CM Ci CO . C.) ^ ^ ^ ^ , fC CM ^ CM ^ o o o J3 a o OOOOXt-^CCCMClC^ 1 ' D. a ^hCMcOOS-^O I-* CM 50 1 . yD COCM^-^ -i C» . U-i # * c O l-l o 03 . Q 0»0 iO'<»*iOOO iQO lOO'-tOiOC OOiCOOO«5cOQOCMC*: -3 T*« 1:0 ir4^000CO 'CO iiCM* Oi -^ GO CO —■ CO CM ■^ C-l-M .—4^—.^— 1* >*« COCM ^CM ^ « 1 * * » * * * fo .*^ b- CS c c .r- ■ fcO^n^kOCOCOCOiOCC- 0-.D • is ' I ! .CO 1 •^j" -0 CO C> "H "rt 1 , , ra ooCM-nco — OQOcrco I'MCnOOC •0 »0 ifS iC CO CO ■— CM t^ •c • 00 i^-MOooc^r^co— 'co»o "»f3^— « ^cricor^'^os >o — CM < I-* O « CM ^ — -^ -- .* • * CO -^ ^ « «- -» I lOOOO-fOOOCMr-tCC g i i b-iOOcDcOOi CO C^ CO (M^^^ ooostMO-*rcococoo>r*ec 000 OO'MlO»-*00t>-.C0C0'M 10 . r^ -(roioot^o^ooor^iceooi-* COCOOSiOCOOO »0 CM CO < 00 CO — , - CM .-. ^ ^H m t '• « OOQOOOSCMC5CMCMCS I ' ■njt 1 ' 1 •-I COlOt^COCMOO *0 CM CO . ■ -*• T-i 1 'l 1 CM^ ^ irtoo locMic-Mr^iooiOs— «co3sh- OOC^lOO-MOrrcOCO «0 "-JTOTT U5»0 't^QO-'S'asi^'fCOOOfC^H •o-fr-Ocot^^"* c>i CM W3^ CO c^t CM ^ ^ CO -* ■0 I 1 ! 1 ■g ; ' 1 ■*^ r\ 1 1 • I Q ; c3 ; Q a 1 c 1 ^ 1 > < t 1 s3 i So Q ; '>',','', n < ^ > o_j -o-o T3 '-C Q « •0 1 C o 3 CO quin River Del aid Pump 'ille Pump and Pump Pump Bridffp 'C ' 3 C c tc ii c-o = e C ' C fl B ' SO ^ u, is is ) CQ bi •Si: a; Mokelumne Kt Point, Sta ?, Staten Isla , Staten I?lan land Kerrv _ C C rt 1 c CMC 4-> PL ^J c Ic "3 Q t3 C CS ■/) ■"■-a — ; uo7? J3 0, c. t. 0. c. cu a* D ■s e Si s a-3, a & E Draini Jersey I Grand Sloug Camp 3 McDon; i^ j :§ s ^1 •- OOio-< CO c^ N eo 000-«f Ca »0 »-* CD O ooo<= C-I CM (TJ 00 CO IC CO CO ooooooor^t^oooooo r- ^ 00 o TT '^3 lo c-i Ci r* x" CO »o -^ O O O O - C^J ■^ ^ CO O -^ CO ^^ oo CO ■<*' ■'f -^ « c^ o t-* t— t-* iC OOOOOO p CO o o ^- o -■! *-■; CO -^ uo — « as 00 CD c^i CO c^ CO oo o 00 CO lO '-^ (M ^^ oooo CO O CO CO CO »^ CO CO lO iO o o o o o *o ^ o o -o oo -^ C5 oo r* CD ■^ ^3* c^ oooooo •^ ri CO uo cjo CO CD CO CO C<) C^l CO O O CO t^ CZ »i5 o oo o »« C c -^ > o B 0--3 -*3 Cms Cl^ 3 " uCQ I i null I i ^11; ffi c^ ^ 2:'^ (il ffi ;l* cc O -n o »« C> u >-> 5 ^ 3 3 H i/j OJ CO (/5 ilOiOOS Cl 00 o OO O>?0 ^ •*« coco »-4 ^ ^^05 • tC •« lO CDCCOO I^COCR aaOCOdC^--" too . c^ 35r^ CI CI • « « *^ ,^ f-i > *-t r-^ o CO ■ ,-4 1 1 1 • 1 > 00 c^ 'i oo lo'irci I osco »cO'^cor^«o>co-^'^ ■^ oo ! . ■^Oco h" C^ iCO*-^ -^ ' • OOOO O^CICOOCt r-^ uo • " CI CI CO CV) ^ t-t-, o O M m ■k^ ClOOO lO'^COCO ^ -i^O -^ 00 to CO ' ^ COM 1 ooa> o «20 — CO .(©'-• CO — » CO t^-^ — CO ' o> 00 -^ ' »0 Oi o oo CI C4 T-H ^ . * _ -» 1— I o tt o o .r: 01 B o a s lyD a> 1— 1 c o 1 >, Q ooctooc^o-^ajt>- ;OcCd0O'rJ'i:OO0'«fCOt^ lOiOh- COy^'^f-iC^-- CI 0:0 1 c. 00 rp — > CI eg CO O CI I-* CO — < > 00 — Tf CI Cvl t-t »-i T-t C1 .-H ^ r-, ,-, ,-. ^ .' G 1 1 1 1 1 1 1 1 , , OOO CO Tp OSO coco c r - 00 1^ ^HQO 1-t-rP 00 CI CI ^ ^ >, 1-4 *J 'E O O ' O . O CO 00 h- OOO 00 CI CO CO CO Cj Ot^ loo cc »o *-< 1 O 00 c* » -^ CO CO -- ooc^ -^ r^ r^ M'^H 1 CO o (M CI 1—1 1 « # CO C^CI r-l . ^ CI 1 ■* 1 OOO oo M* t— -^ *0 00 to *-" i—Cl coQO coco CO eo oo coc^ci OC50OC»0cCt— CO r^ CI CO ' — « o> CI C^rt» .« coc» ^ -« ■2 '•§ ; i i : g • 1 1 € ;,S ; : ; ; .s a o o 1 ■ \% i) Delta Island. a Steam Drain.. ; c 1 t. ;C s 1 1^ 1 ' • .-3 '13-a HD 'tr ;.s :■§ i : 'T3 1 J 3 1 1 ' i'!^ c c c c: ' c ' C S o K 6 £ •— « CI C I tf' rt <^ ;^ ! rt ; c5 ; ; '_rt o o ; ;o >:. : i I . "c ' "^rr-"^ ' "eT "jj c . i .To , c ' Tj ^*3 GO i ;s-^ s c ^ c"^ C c a •— ' ft)'"' CM c b . ;^5'2-2c ^ Sin Joaquin Riv .Middle hiver P Mansion House Stockton Count Clifton Court F Stockton Williams Bridg( Whitehall Mossdale Highv lokelum pst Poin 3, State , Staten hnd Fe 1, State 9. State cS ;-r3 :s «c^ £5 nage W Drain. Ishn igh. .. 35, Sta nald Di Island eville D 11, Sta ! 2: gcci-^ — c)H'?'>?0 - CO OS OS <— ' CD t*- 05 CO "O l>- lO lO QO OS CO CO OS ^H Oi C^l 1-n-i (M ,-< CM ^ OO »^ iO O O I~ O (-- — ' C3 »-« t^ t^ Tf« CO o c^J t^ lO '-' C50 O OO •— ' CO OS 00 Cvl .— I 4C ^ OJ '-« '-H i-> lO O C> »— QO lO o CM CD CO C^ OS OCi 1^ t-* CD iO CO •-' W ooo-^oco^cios t--oco-^o*ocoTrcD CI C^» .-H C-1 - TT CO OS CI OS »0 U3 OO Co . ^ 00 O OO -^ ■ CD CO 1— ' CO O o»o o o lO -^ -^ CO TT »0 rr CO ooos' S-e « OQtt:;o_;S n E — ^1 "Cm ^ e^fi. PSB- c>i:fiH Ccc cs go. »- w C3 c- G^ Via itll£&l i^l> ;o o : cO 5 s-^5 K »'. .»i a; C 372 DIVISION OF WATER RESOURCES O w •0 c u 3 _C c d ■o c Q Z 3 1 C H PI < CO o >. u >-l J 01 CO z VI <" ^ 3 H (/J u c o H N z t; UJ j2 ?• < o: C u '" < l: to (0 w z a u (/) CO o H Z to 1 a o o o o u. OJ Q. lU C o -g C c .§• 1 c i o >> ta Q CO OOOOO 1^ t~00 -^ -^ I^^CO O 00 (O QO 1 CO 1 ! 1 1 1 ^41111 1 • 1 . t 1 1 1 11(1 50 COOOOOOOOO ^ C^ •«»» CS M"^ *0 00 ■* ^^ O 'OS t;0 — QO OOOOO CI ! Mil! Oi 00 00 00 t>- 00 c^i t^ OS ^^ oi lo to 00 ICO o i^H ir-co-« o »o o o «s eOeO»« cOiO»Ot^ 'OS CO • OS i ■^ OO CO oo »o ^ »c »o • * * . 1 C4 ^^ 1^ ^' O_00 CO o - iO . ' ■ ■ t • I • • i 00 ^ !oo w oo :• ^oooccc^icscot^co «ooo-^ •0U3OOI0 cc-"'«reooi 1^ too O) lO 1 1 1 •^ ^00 00 * coco-Hcor^'Ocoost-'^ r^"n p m l^iOCO O 00 (M :o I CS I ! I ! . kO < < • • . • .III O -* -^00 00 OCDOOCJCSiOOCSOO oscot* Qoi-^»ca>ic— ' * • » .— 1 I los lososd 1130 OiOO OO OS CO »0 OO 1^ tn CO ^ 1^ * 00 U5 1 CO 1 1 < ' 1 CO 1 1 1 • 1 * I 1 ) • o CO oac ^ • • « ,-^ ,— 1 1 !• 1 # U5 lus llO lO i->r ■CI h- tco . oo Station -g c g 1 Q > c g = si a bi > t s ■1 l] II c ^ |£ Is I , t u "a ii en " SI ceo. ^ CN & c a "a C c ;_£ a*'"' bO c -a 0. Drainage Water in Delta Islands Jersey Drain... Grand Idand Drain, Steamboat Slough Camp 35, Staten Island Drain McDonald Drain Bacon Idand Drain Mandcville Drain San Francisco, San Pablo and Suisun Bays Point Orient Point Davis ._ Bulls Head Point-. Bay Point 0. and A. Ferry 1 a a ^ a e -1 o rt c5 >» rt c5 r .a s E 1 1 i a 5 1 VARIATION' AND CONTROL OF SALINITY 373 W I O lO i-« ^ O "-H 060004 1 loo-^ r-o o COO « CO fo *o lo cq cs oo CO ■— ' 'SJ' CO t^ -^ cc c^ C^ --^ i-" ?0 M ^ lO 00 oo a> ec CO -^ CO C<1 <-< o c^ •-< *0 OCOOOQO ^ C^ .-^ rl CO CDOO O Oi -^ lO TT CO OOOt— CO— «fOOt^C.t: O *' w w = 2:ko g •a 03 u ■s>> SQ^. «- - ^ -z 4: 0'S:S0^K«*:?vU!3:Cii«^'^x o _ o S J « = "O t: S*-- ^ =: ' 57^ s o^= o y-r.: 374 DIVISION OP WATER RESOURCES o o^ I— 1 >-' < CQ U tn M-l u z <' i; a -a E s: ?: bD <: J= OT u U oi i! w a< (fl fe Q v*_ 7. a < 1 "2 1 C C c Q 7. § ,9 h- 1 U D a j=5 n ^ >> U >-> C3 3 'J) 3 H (/) u o (-1 o Z4J U < CO a; c CO Z O H > u {/> CQ O >^ H a E a o o o o a •a-o Q'w -dT3 c a rt OS > c; ca c «i c'"' fc c c C C C) C C) V OJ CO S-o a: CO c 09 cc -g a s^ s e-aa C^OCJE-CJOKO It » a a 5 at 1. a a f >,t3 o a O a c3 ►-5 O tn oo oi '^ oi Oi tn O lO U) O U3 to 40 »-« CC lO « '^ CC ^f IM cs «5 CD OOiOO to -^ to oa to CO OS to o o »o o OO C^ t^ CO toco CT>r* -j:.oo :o o to 01 O CO OO lO CI oooooo to O C^ to 00 o to -^ c^ o -^ t^ oooooo»o to OS CI OO O C-J oo l^ CO O 00 »C 00 CO • oo t I - (M ' C^ CO •s 09 Sq-o — cD ft; B'r CO o « CGC e u. -rr 9. «= a CJ VARIATION AND CONTROL OP SALINITY 375 CO — '•r to •JD Ol CD t— ;:; cc =o c^) I-* c- (M— ' — * OCCOO— '^H(MCO ,^. 00 c^ (M o oo 35 ; •^ OO O O Oi 1-4 O 05 Oi CO CO C<) (M "^ O t^ OS CO 00 CO ■^0'-D01000i^ S ^- K t2 5 C &o JO zn O ,0 u o ^O t. ^ 3 ^ C3 ? O - ■- '-■-" — ■" ^--^ — - -t ^ ^ Q £ 5«t-^ S — S c -^ -S p s' = S. "^ — " c = cc CO gCQ £3 376 DIVISION OF WATER KESOURCES •0 V •O 3 "o C o u < < 09 o U 1-4 u z < b z < o; u a D Q Z < oi o <; Z o > a w t/1 ca o W3 < n s t3 r UJ ra D C) c Z l-H D 3 c < ca >> ■— 1 « z 3 < 3 Cfl t) 6 c H Z (U u to eai3 i: a a) a." c «^ E.S CO t^ -^ •«*< ■o-o O C O OJ O) C'fc. - S-1 a a L. . a S^ i a a T-, «5 ^ S "S o -^o "lO g-o ^H (M f_, Ol O -M c. o. 4, o."^ a S STi6 it a . f! « .T c: > ^ s" o, Fl >, 3 •T3 a ^ "?. a u a CO .2 V 2 * ^ B oS VARIATION AND CONTROL OF SALINITY 377 TABLE 34 MISCELLANEOUS SALINITY OBSERVATIONS, PRIOR TO 1920 Location Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop So ithern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop Southern Pacific Railroad Bridge, near Lathrop ttsburg- ttsburg_ ttsburg.. ttsburg . . ttsburg- . ttsburg. - ttsburg., ttsburg.. ttsburg.. ttsburg. . ttsburg.. ttsburg.. ttsburg.. ttsburg. . ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg. . ttsburg. . ttsburg.. ttsburg.. ttsburg.. ttsburg. . ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg. . ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg.. ttsburg- . ttsburg.. ttsburg- . Sept. 21-30, 1906. Oct. 1-10, 1906. Oct. 11-20, 1906. Oct. 21-31, 1906. Nov. 1-10, 1906. Nov. 11-20, 1906. Aug. 7-16, 1908. Aug. 17-26, 1908 Aug. 27 to Sept. 5, 1908. Sept. 6-15, 1908 Sept. 16-25, 1908. Sept. 26 July 25 July 27 Aug. Aug. Aug. Aug. Aug. Aug. Aug. 10 Aug. 12 Aug. 18, Aug. 29, Sept. 8 Oct. 22 Dec. 3 Dec. 6 Dec. 9, Dec. 11 Dec. 27 Jan. 18, Aug. 28, Sept. 5 Sept. 8, Sept. 11 Sept. 13 Sept. 15 Sept. 20, Sept. 21 Oct. 5 Jan. 8 Feb. 2 April 25 May 30, Aug. 31 Sept. 12 Sept. 17 Oct. 23 Nov. 11 July 16, Aug. 6 Aug. 13 Aug. 19, Aug. 26 Aug. 27, Oct. 25 Oct. 27 Nov. 6, Nov. 11 Nov. 17, Nov. 21 Salinity in parts of chlorine per 100,000 parts of water 6 8 9 9 8 7 10 10 11 12 12 9 40 25 21 50 21 39 19 31 22 36 37 35 58 46 12 14 5 6 6 3 14 7 26 30 15 22 54 41 19 50 4 2 3 18 18 38 42 7 14 48 31 52 67 55 84 106 95 102 134 32 Tidal phase Not given Not given Not given Not given Not given Not given Not given Not given Not given Not given Not given Not given High H high Low Low Low J^tide Low H high Low Low Low Low Low Low Low High High High Htide High High Low High Low Low Low Low Low Low High High High Low Low Low H high Low Low Low Low Low Low Low Low Low Low Low H high High Low Observer U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Survey' U. S. Geological Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Black Diamond Survey' Water Co.= Water Co.= Water C0.2 Water Co.* Water Co.' Water Co.- Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' Water Co.' 378 DIVISION OF WATER RESOURCES TABLE 34— Continued MISCELLANEOUS SALINITY OBSERVATIONS, PRIOR TO 1920 Location Pittsburg. Pittsburg. Pittsburg . Pittsburg. Pittsburg. Pittsl)urg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg- Pittsburg - Pittsburg. Pittsburg. Pittsburg. Pittsburg - Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg- Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Pittsburg. Sherman Island, opposite Toland's Landing Antiocli Dutch Slough False River Anlioch Dutch Slough F'llsc River Toland's Landing Toland's Landing Suisun Wharf, Suisun Suisiin Wharf, Suisun_ Suisun Wharf, Suisun Suisun Wharf, Suisun Suisun Wharf, Suisun Suisun Wharf, Suisun Suisun Wharf, Suisun Suisun Wharf, Suisun Suisun Wharf, Suisun Suisun Wharf, Suisun Nov. Nov. Aug. Aug. Nov. Dec. Aug. Nov. Dec. Sept. Sept. Oct. Oct. Oct. Oct. Oct. Oct. Oct. Oct. Oct. Oct. Oct. Oct. Oct. Feb. 23. 25, 13, 31, 23, 12. ^. 20. 23. 26, 7, 9, 12, 13, 16, 7, 8, 9. 10, 12, 13, 14. 15. 25. 1913... 1913... 1914... 1914... 1914... 1914... 1915... 1915... 1915... 1916... 1916... 1916... 1916... 1916... 1916... 1916... 1916... 1916... 1916... 1910... 1916... 1916... 1916... 1916... 1919— July 9. 1919. July 14, 1919- Aug. 16, 1919. Aug. 28, 1919. Sept. 16, 1919- Sept. 27, 1919. Oct. 3, 1919. Oct. 14. 1919- Oct. 29, 1919.. Oct. 31, 1919.. Nov. 9. 1919- Nov. 24. 1919- Dec. 16, 1919- Dec. 31, 1919. Sept. Sept. Sept. Sept. Sept. Sept. Sept. Sept. Nov. Jan. Jan. Jan. Jan. Jan. Jan. Feb. Feb. Feb. Feb. 26, 26, 27, 26, 20, 20, 20, 20, 1, 4. 6, 11, 13, 15, 31. 2. 7. 9. 15. 1913. 1913. 1913. 1913. 1913. 1913. 1913. 1913. 1913. 1916. 1916. 1916. 1916. 1916. 1916- 1916. 1916. 1916. 1916. Salinity in parts of chlorine per 100.000 parts of water 31 102 10 34 30 1 9 49 44 48 27 32 24 23 13 59 70 70 23 76 85 76 35 10 66 236 561 493 451 425 221 183 65 65 58 47 13 14 3 63 4 3 112 6 2 1 1 71 70 37 36 22 39 34 32 34 39 Tidal phase High High Yi high J^high Low 5 (Capt. S. A. Johnson) California Hawaiian Sugar Co.* (Capt. S. A. Johnson) California Hawaiian Sugar Co.» (Capt. S. A. Johnson) California Hawaiian Sugar Co.« (Capt. S. A. Johnson) California Hawaiian Sugar Co.» (Capt. S. A. Johnson) California Hawaiian Sugar Co. s (Capt. S. A .Johnson) California Hawaiian Sugar Co.» (Capt. S. A. Johnson) California Hawaiian Sugar Co.« (Capt. S. A. Johnson) C.ilif^rnia Hawaiian Sjgar Co.» (Capt. S. A. Johnson) California Hawaiian Sugar Co.» (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) 884 DIVISION OF WATER RESOTTRCES TABLE 34 — Continued MISCELLANEOUS SALINITY OBSERVATIONS, PRIOR TO 1920 Location Newtown Junction of Sacramento River and Cache Slough.. Miner Slough... Prospect Slough-.- Lindsey Slough - Solano Irrigated Farms Canal _ End of Solano Irrigated Farms Canal Halfway up Lindsey Slough. One-half mile up Lindsey Slough Two miles up Hass Slough Junction of Hass Slough and Alamo Creek Main Prairie Junction of Steamboat and Cache sloughs - Junction of Three Mile Slough and Seven Mile Slough Sacramento River, end of Three Mile Slough Emmaton Landing Perley's Landing Williams Landing Rio Vista Junction Point Junction of Cache and Lind- sey ploughs.. . One mile up Lindsey Slough- Two miU s up Lindsey Slough Three miles up Lindsey Slough Four miles up Lindsey Slough . Entrance of Solano Irri- gated Farms Canal Intake of Solano Irrigated Farms Canal Junction of Hass Slough and Alamo Creek Entrance to Steamboat Slough Date Nov. 11, 1919. Nov. 11, 1919. Nov. 11. 1919. Nov. 11. 1919- Nov. 11, 1919. Nov. 11, 1919. Nov. 11, 1919. Nov. 11, 1919. Nov. 11, 1919. Nov. 11. 1919. Nov. 11, 1919.. Nov. 11, 1919. Nov. 12, 1919 Nov. 13, 1919- Nov. 13, 1919- Nov. 13, 1919- Nov. 13. 1919. Nov. 13. 1919- Dec. 3, 1919. Dec. 3, 1919.. Dec. 3, 1919.. Dec. 3, 1919. Dec. 3, 1919. Dec. 3, 1919- Dec. 3, 1919.. Dec. 3. 1919. Dec. 3, 1919. Dec. 3. 1919. Dec. 4, 1919. Salinity in parts of chlorine per 100,000 parts of water Tidal phase High High First of ebb First of ebb First of ebb Middle of ebb Low First of flood First of flood First of flood First of flood Middle of flood First of flood High Observer 2 High 3 First of ebb 7 First of ebb 28 Ebb 2 High 2 High 2 Flood 2 Flood 3 Flood 5 Flood 5 Flood 6 Flood 6 High 5 First of ebb 2 High California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.» (Capt. S. A. Johnson) California Hawaiian Sugar Co.* (Capt. S. A. Johnson) California Hawaiian Sugar Co.« (Capt. S. A. Johnson) California Hawaiian Sugar Co.» (Capt. S. A. Johnson) California Hawaiian Sugar Co.« (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.* (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. 8. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Co.' (Capt. S. A. Johnson) California Hawaiian Sugar Cc.« (Capt. S. A. Johnson) VARIATION AND CONTROL OF SALINITY 385 TABLE 34- Concluded MISCELLANEOUS SALINITY OBSERVATIONS, PRIOR TO 1920 Salinity in parts of Location Date chlorine per 100,000 parts of water Tidal phase Observer Entrance to Miner Slough, __ Dec. 4,1919 2 Flood California Hawaiian Sugar Co.i (Capt. S. A. Johnson) Entrance to Prospect Slough. Dec. 4,1919 2 Flood California Hawaiian Sugar Co.» (Cai)t. S. A. Johnson) Entrance to Egbert Cu' Dec. 4,1919 2 Flood California Hawaiian Sugar Co.* (Capt. S. A. Johnson) Entrance to Duck Slough. .. Dec. 4, 1919 1 Flood California Hawaiian Sugar Co.' (Capt. S. A. Johnson) Head of Netherlands Canal. Dec. 4, 1919.. 1 High California Hawaiian Sugar Co.* (Capt. S. A. Johnson) Halfway up Netherlands Canal Dec. 4,1919 1 First of ebb California Hawaiian Sugar Co. 8 (Capt. S. A. Johnson) Junction of Netherlands Canal and Dutch Slough. . Dec. 4, 1919 1 Ebb California Hawaiian Sugar Co. 8 (Capt. S. A. Johnson) ' From Water Supply Paper Number 237, pages 46 and 47. - From records on file in office of State Division of Water Resources, furnished by Black Diamond Water Company of Pittsburg in 1916. 3 From data on file in office of State Division of Water Resources. Values of salinity approximate, having been deter- mined by the electrolytic method. * From records in Volumes II and III of transcript of "Antioch" suit. ' From report on Richmond Municipal Water District, by Haviland, Dozier and Tibbetts, 1913. '^ From data furnished by Thomas H. Means, Consulting Engineer. ' From records on file in office of Division of Water Resources of salinity cbservaticns at pumping plant of East Con- tra Costa Irrigation Company (now East Contra Costa Irrigation District) near west end of Indian Slough in San Joaquin River Delta. See Tables 33 and 35 for records in 1920 and subsequent thereto. ' From records on file in office cf Division of Water Resources, furnished Ly California and Hawaiian Sugar Refining Corporation. 25—80995 386 DIVISION OF WATER RESOURCES TABLE 35 MISCELLANEOUS SALINITY OBSERVATIONS, AFTER 1920 Salinity in parts of ' Location Date chlorine per 100,000 parts of water Tidal phase Observer Dumbarton Bridge .-- July 19, 1923 1,730 High-Low San Francisco Bay Piling (^omniitteei Marine Dumbarton Bridge July 20, 1923 1,700 Low-Low San Francisco Bay Piling Committee' Marine Dumbarton Bridge - - . . July 20, 1923 1,710 High-Low San Francisco Bay Piling Committee' Marine Dumbarton Bridge July 27, 1923 1,76') Low-Low San Francisco Bay Piling Committee' Marine Oakland Mole July 10, 1923 1,593 High-Low San Francisco Bay Pi ii;g Committi'c' Marine Oakland Mole July 11, 1923 1,593 Low-Low San Francisco Bay Piling Committee' Marine Oakland Mole... July 16, 1923 1,620 High-Low San Franci.sco Bay Piling Committee' Marine Oakland Mole - . July 17, 1923 1,623 Low-Low San Francisco Bay Piling Committee' Marine Oakland Mole- July 23, 1923 1,730 High-Low San Francisco Bay Piling Committee' Marine Oakland Mole. July 24, 1923 1,670 Low-Low San Francisco Bay Piling Committee' Marine San Francisco (Ferry Bldg.) - July 11, 1923 1,743 High-High San Francisco Bay Piling Committee' Marine San Francisco (Ferry Bldg.) - July 12, 1023--.- - - 1,643 Low-Low San Francisco Bay Piling Committee' Marine San Francisco (Ferry Bldg.). July 17, 1923... 1,780 High-Low San Francisco Bay Piling Committee' Marine San Francisco (Ferry Bldg.). July 18, 1923 1,790 Low-High San Francisco Bay Piling Committee' Marine San Francisco (Ferry Bldg.). July 24,1923 1,810 High-High San Francisco Bay Piling Committee' Marine San Francisco (Ferry Bldg-.). July 25,1923 1,723 Low-Low San Francisco Bay Piling Committee' Marine Fort Scott (Golden Gate) . . . July 12, 19-3--. 1,850 High-High San Francisco Bay Piling Committee' Marine Fort Scott (Golden Gate) . . July 13, 1923 1,783 Low-Lew San Francisco Bay Piling Committee' Marine Fort Scott (Golden Gatel . . . July 18, 1993 1,883 High-High San Francis^co Bay PilingCommittee' Marine Fort Scott (Golden Gate) . . . July 19, K23 1,910 Low-High San Francisco Bay Piling Committee' Marine Fort Scott (Golden Gate) . - - July 25, 1923 1,933 High-High San Francisco Bay Piling Committee' Marine Fort Scott (Golden Gate) . - - July 26, 1923... 1,853 Low-Low San Francisco Bay Piling Committee' Marine Point San PaWo Sito Feb. 3, 1925 425 V. S. Bureau if Riclamation' Point San Pablo Site Mar. 12, 1925 935 U. S. Bureau of Reclamation' Point San Pablo Site .'Vpri Miiv 1(5 1925 835 II S Bureau of Rpolamntinn^ Point San Pablo Site 16, 1925 050 U.S. Bureau of Hoc!.-' mation' Point San Pablo Site June 15, 19?5 1,135 U. S. Bureau of Reclamation' Point San Pablo Site July Sept 7 1925 1,315 U S Bureau of Heclamation' Point San Pablo Site. - . ..- 2, 1925 1.615 U. S. Bureau of Reclamation' Point San Pablo Site Oct. Nov 16, 1925 17, 1925... 1,.58J 1,530 U. S. Bureau of Recia U. S. Burrau of Rccla mation' Point San Pablo Site.-. mation' Point San Pal;lo Site Dec. Jan. Feb. 17, 1925 1,513 1,510 86 J V. S. Bureau of Rpcla U. S. Bureau of RecIa U. S. Bureau of RecIa mation' Point San Pablo Site 15, 1926— mation' Point San Pablo Site . . . 12, 1926 15,510 feet south of Marc Island Strait Bascule Bridpe - - - - - Jan. 14, 1923 . 633 High U. S. Navy Yard' 15,500 feet south of Mare Island Strait Bascule Bridge Fob 16, 1923 430 High U. S. Navy Yard" 15,500 feet south of Marc Island Strait Bascule Bridge Mar 16,1923 450 High U. S. Navy Yard' 15,500 feet south of Mare Island Strait Bascule Bridge . . April 18 1923 330 High U. S. Navy Yard' 15,500 feet south of Marc Island Strait Bascule Bridge May Ifi. 1923 270 High U. S. Navy Yard' 15,500 feet south of Mare Island Strait Bascule Bridge July 16.1923 -..- 790 High U. S. Navy Yard' VARIATION AND CONTROL OF SALINITY 387 TABLE 35 — Continued MISCELLANEOUS SALINITY OBSERVATIONS, AFTER 1920 Location 15,500 feet south of Mare Island Strait Bascule Bridge 15,500 feet south of Mare Island Strait Bascule Bridge.. 15,500 feet south of Mare Island Strait Bascule Bridge 15,500 feet south of Mare Island Strait Bascule Bridge 15,500 feet south of Mare Island Strait Bascule Bridge 15,500 feet south of Mare Island Strait Bascule Bridge 15,500 feet south of Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge ■. Mare Island Strait Bascule Bridge Mare Island Strait Bascule Bridge Army Point Site • Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Army Point Site Date Sept. 28, 1823.. Oct. 28, 1923.. Nov. 18, 1923.. Dec. 16, 1923.. Jan. 30, 1924.. May 18, 1924.. June 28, 1924_. Jan. 14, 1923.. Feb. 16, 1923.. Mar. 16, 1923. . April 18, 1923.. May 16, 1923_. July 16,1923.. Sept. 28, 1923.. Oct. 28, 1923.. Nov. 18, 1923- Dec. 16, 1923.. Jan. 30, 1924.. May 18, 1924.. June 28, 1924.. Feb. 5, 1924.. Feb. 13, 1924.. Feb. 22, 1924_. Mar. 1, 1924.. Mar. 11, 1924.. Mar. 28, 1924.. April 8, 1924-. April 15, 1924-. April 22, 1924.. April 30, 1924.. Jan. 1, 1925.. Jan. 11, 1925_. Jan. 18,1925.. Jan. 26, 1925.. Feb. 1, 1925.. Feb. 10, 1925.. Feb. 21, 1925- Feb. 25, 1925.. Mar. 3, 1925.. Mar. 12, 1925.. Mar. 18, 1925.. Mar. 26, 1925.. April 2, 1925.- April 9, 1925.. April 16, 1925- April 24, 1925- April 30, 1925- Salinity in parts of chlorine per 100,000 parts of water 1,260 1,180 1,350 1,190 1,060 1,070 • 1,430 550 380 460 280 250 630 1,190 1,060 1,250 1,110 970 1,040 ,250 525 325 325 375 425 650 660 385 640 565 325 385 375 510 335 15 45 10 225 125 165 120 238 82 55 30 115 Tidal pha.se High High High High High High High High High High High High High High High High High High High High Observer U. S. Navy Yard' V. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' U. S. Navy Yard' Mounta Mounta: Mounta Mounta Mounta Mounta: Mounta Mounta Mounta Mountai Mounta Mounta Mounta Mounta Mounta Mounta Mounta Mounta: Mounta Mounta Mounta Mountai Mounta Mounta Mounta Mounta: Mounta n Copper Co, in Copper Co. in Copper Co. in Copper Co, in Copper Co, in Copper Co, n Copper Co, ,n Copper Co, in Copper Co, in Copper Co, in Copper Co. n Copper Co. n Copper Co, in Copper Co. n Copper Co. n Copper Co. n Copper Co. in Copper Co. in Copper Co. in Copper Co. ;n Copper Co. in Copper Co. n Copper Co. n Copper Co. in Copper Co. in Copper Co. ,n Copper Co. 388 DIVISION OF WATER RESOURCES TABLE 35— Continued MISCELLANEOUS SALINITY OBSERVATIONS, AFTER 1920 Location Date Salinity in parts of chlorine per 100.000 parts of water Tidal phase Observer East Contra Costa Irriga- tion Company pump East Contra Ca^ta Irriga- tion Company pump Jan. 4,1920... Jan. 12, 1920 Jan. 22, 1923 Jan. 29,1920 Jan. 31, 1920 21 22 20 23 19 17 18 16 14 13 14 14 14 15 15 15 15 14 13 13 13 9 9 7 5 4 3 3 2 3 4 4 5 5 4 3 3 4 East Contra Costa Irrig. Co.» East Contra Costa Irrig. Co.' East Contra Costa rriga- tion Company pump East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pumo . East Con'.ra Costa Irriga- tion Company pump --- East Contra Costa Irrig. Co.' Eist Contra Casta Irrig. Co.* East Contra Coita Irriga- tion Company pump Feb. 9.1920 Feb. P, 1920 Feb. 14, 1920 Feb. 17, 1023 Feb. 19, 1923... Feb. 21, 1920 Feb. 23, 1923 Feb. 25, 1920 East Contra Cost** Irrig. Co.' East Contra Costa Irriga- tion Company pump East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump . - _ . East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump. East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Comjany pump Feb. 28, 1920 East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump Mar. 4, 1920 East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump Mar. 6, 1920 East Contra Co'ta Irrig. Co.' East Contra Costa Irriga- tion Company pump Mar. 8, 1920 East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump. . .. Mar. 11, IQ'O Mar. 13, 1923 East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump r East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Comp.vny pump East Contra Costa Irriga- tion Company pump East Contra Costa Irriga- tion Company pump Mar. 15, 1920... Mar. 17. 1920 Mar. 24, 1920 . . Ea.st Contra Costa Irrig. Co.; East Contra Costa Irrijr. Co.' East Contra Costa Irrig. Co.' East Contra Costa irriga- tion Company i,ump . Mar. 2.5, 1920 Mar. 27, 1920 East Contra Costa Irrig. Co.' East Contra Costa Irriga- tion Company pump East Co^itra Costa Irri^ flood 520 Mebb 293 High 11 Hchh 5 High 4 High 3 High 2 High 4 ^ebb 4 Low 2 High 22 Low 2 High 3 Low 2 2 3^ ebb Low 3 ?i flood 2 High 2 J^ebb 2 >i flood 2 Jiebb East Contra Costa Irrig. Co.> East Contra Costa Irrig. Co.' East Contra Costa Irrig. Co.* East Contra Costa Irrig. Co.» East Contra Costa Irrig. Co.* East Contra Costa Irrig. Co.» East Contra Costa Irrig. Co.' East Contra Costa Irrig. Co.' East Contra Costa Irrig. Co.' East Contra Costa Irrig. Co.' East Contra Costa Irrig. Co.' East Contra Costa Irrig. Co.' East Contra Costa Irrig. Co.' East Conjra Costa Irrig. Co.' Genera Genera Genera General Genera Genera Genera Genera Genera Genera Genera Genera General Genera] Genera Genera! General Genera Genera Genera Genera Genera Genera Genera Genera General Genera Genera Genera General Genera Genera Chemical Company* Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Comnpay' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' General Chemical Company' 3f)0 DIVISION OF WATIMt RESOURCES TABLE 35 -Continued MISCELLANEOUS SALINITY OBSERVATIONS, AFTER 1920 Location Nicholls NichoUs Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls- Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls NichoUs Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls - Mar. 30, 1921... April 5, 1921... April 11, 1921... April 18, 1921... April 25, 1921... May 2, 1921... May 9, 1921... May 16, 1921... May 23, 1921... May 31, 1921... June 6,1921... June 13, 1921... June 20, 1921... June 27, 1921... July 5, 1921... July 7, 1921... July 9, 1921... July 12, 1921... Aug. 3, 1921... Aug. 8, 1921 .. Aug. 15, 1921... Aug. 21, 1921... Aug. 29, 1921... Sept. 5, 1921... Sept. 11, 1921... Sept. 20, 1921... Sept. 26, 1921 ... Sept. 27, 1921... Oct. 2, 1921._. Oct. 11, 1921... Oct. 17. 1921... Oct. 24, 1921... Oct. 31, 1921... Nov. 8, 1921... Nov. 15, 1921. . Nov. 21, 1921... Nov. 29, 1921... Dec. 5, 1921... Dec. 12, 1921... Dec. 19, 1921... Dec. 27, 1921... Jan. 7, 1922... Jan. 16, 1922... Jan. 23, 1922... Jan. 30, 1922 .. Fob. 7, 1922... Feb. 13, 1922... Feb. 20, 1922... Feb. 27, 1922... Mar. 6, 1922... Mar. 13, 1922... Mar. 20, 1922... Mar. 29, 1922... April 3, 1922... April 10, 1922... April 17, 1922... April 24, 1922... Mav 1, 1922... May 8, 1922... May 15, 1922 .„ May 22, 1922... Mav 29, 1922... June 5, 1922... June 12, 1922... June 19, 1922... June 26, 1922... July «, 1922... Julv 10, 1922... Aug. 7, 1922... Aug. 14, 1922... Aug. 21, 1922... Aug. 28, 1922... Sept. 4, 1922... Sept. 11, 1922... Sept. 18, 1922... Salinity in parts of chlorine per 100,000 parts of water 2 1 2 2 1 K 2 1 2 1 2 1 2 1 60 34 169 149 382 369 268 616 701 616 817 819 718 761 867 659 615 613 634 509 474 504 404 308 593 425 150 42 30 130 70 248 5 4 2 2 4 2 3 2 2 2 2 ■ 2 1 1 1 1 1 1 1 2 4 167 266 451 407 596 575 696 Tidal phase J^ flood f.s flood Low H flood ^ flood 1^ flood Low Ji flood Low Low Low ?s flood y^ ebb 3^ flood Jiebb Ji flood Ji flood High Low High Ig ebb High >4 flood High High 3-iebb }^ flood Jiebb High Hebb High Hebb High Low High Low >^ebb Low High Low High Low J^^ebb Low H ebb Low Observer Genera! Genera Genera! Genera Genera Genera General Genera! Genera! Genera Genera Genera! Genera! Genera! Genera! General Genera! Genera! Genera! Genera Genera! General General General Genera! Genera! Genera Genera Genera: Genera! General General General General General Genera! Genera General Genera Genera Genera Genera Genera General Genera Genera Genera Genera! General Genera Genera Genera Genera General Genera! Genera Genera Genera Genera Genera Genera Genera Genera Genera Genera General (!ienera! General Genera Genera Genera Genera General Genera Genera ,1 Chemical I Chemica ,1 Chemical \ Chemica 1 Chemica 1 Chemica 1 Chemica! 1 Chemical ,1 Chemical 1 Chemical 1 Chemica ,1 Chemica' I Chemica 1 Chemica! 1 Chemical 1 Chemica 1 Chemical 1 Chemical 1 Chemical 1 Chemical 1 Chemical 1 Chemica 1 Chemica 1 Chemical I Chemica 1 Chemical 1 Chemical 1 Chemica 1 Chemica 1 Chemical I Chemica! 1 Chemica! ,1 Chemical 1 Chemical 1 Chemica! 1 Chemica! 1 Chemica 1 Chemica 1 Chemical I Chemica 1 Chemica 1 Chemica I Chemica 1 Chemicu I Chemica I Chemica 1 Chemical 1 Chemica! 1 Chemica 1 Cyemica 1 Chemica I Chemica 1 Chemica! I Chcmic; 1 Chemical 1 C^hemica 1 Chemica 1 Chemica I Chemical I Chemical I Chemicii I Chemica I Chcmic;i 1 Chemica I Chemica 1 Chemici I Chemic I Chemica 1 Chemica 1 Chemica! I Chemica 1 Chemica .1 Chemical 1 Chemical 1 Chemical .1 Company* 1 Company* 1 Company' 1 Company' 1 Company' .1 Company" ,1 Company' .1 Company' 1 Company' 1 Company' Company' 1 Company' 1 Company' .1 Company' 1 Company' 1 Company « 1 Company • I Company' 1 Company' 1 Company' ,1 Company' I Company" 1 Company' 1 Company' 1 Company' 1 Company' .1 Company' 1 Company" 1 Company' 1 Company' 1 Company' ,1 Company' 1 Company' I Company' 1 Company' ,1 Company' 1 Company' 1 Company' 1 Company' 1 Company" I Company" 1 Company" 1 Company' 1 Company' 1 Company' 1 Company' I Company" 1 Company' 1 Company' 1 Company" 1 Company' I Company' 1 Company' I Company' 1 Company" I Company' 1 Company' I Company* .1 Company' I Company' 1 Company' 1 Company' I Company' 1 (!'ompany« I Company' I Company' I Company" 1 Company' I Company" I Company' I Company' 1 Company" I Company' 1 Company < 1 Company' 392 DIVISION OF WATER RESOURCES TABLE 35 -Concluded MISCELLANEOUS SALINITY OBSERVATIONS, AFTER 1920 Location Date Salinity in parts of chlorine per 100,000 parts of water Tidal phase Observer Mar. 31, 1924 377 1G7 152 97 290 88 197 280 393 543 G19 952 1,166 1,126 1,139 1,245 1,199 1,365 1,245 1,439 1,345 1,492 1,425 1,461 1,346 1,346 645 1,221 1,121 786 680 288 660 345 528 195 538 58 High Low Low H flood J^ flood Low Low ?^ flood Low Low Low ?^ flood Low High Low High Low J^ebb Low Low H flood Hebb Low •as Mebb High High High Low High Low High High High High High High General Chemical Company' NichoIU April?, 1924 General Chemical Company* Nicholls - - April 14, 1924 General Chemical Company' April 21, 1924 General Chemical Company' Nicholls April 28, 1924 General Chemical Company • Nicholls .. May 5,1924 General Chemical Company. Nicholls May 12, 1924 General Chemical Company' Nicholls May 19. 1924 May 26, 1924 _ General Chemical Company' General Chemical Company* Nicholls June 2, 1924.. General Chemical Company' Nicholls June 9, 1924 General Chemical Company' June 30, 1924 General Chemical Company' Nicholls July 7, 1924 General Chemical Company' Nicholls -- July 14, 1924 General Chemical Company' Nicholls- July 21, 1924 General Chemical Company' Nicholls July 28, 1924.. General Chemical Company' Nicholls - Aug. 4,1924 General Chemical Compary' Nicholls Aug. 11, 1924 General Chemical Company' Nicholls Aug. 18, 1924.. General Chemical Company' Aug. 25, 1924 General Chemical Company' Sept. 1, 1924 General Chemical Company' Nicholls Sept. 8, 1924-. ... General Chemical Company' Sept. 15, 1924 General Chemical Company' Nicholls Sept. 22, 1924-.. General Chemical Company' Nicholls Sept. 29, 1924 General Chemical Company' Nicholls Oct. 6,1924 General Chemical Company' Oct. 13, 1924 General Chemical Company' Nicholls _ - Oct. 20, 1924.. General Chemical Company' Oct. 27, 1924 General Chemical Company' Nicholls -- - Nov. 3, 1924 General Chemical Company' Nicholls Nov. 10, 1924 General Chemical Company' Nov. 17, 1924 General Chemical Company' Nicholls Nov. 24, 1924 General Chemical Company' Nicholls Dec. 1, 1924 General Chemic.il Company' Nicholls -- Dec. 8,1924 General Chemical Company' Nicholls Dec. 15, 1924 General Chemical Company' Nicholls Dec. 22, 1924 Dec. 29, 1924 General Chemical Company' Nicholls General Chemical Company' ' From dat] in final report, 1927, of San Francisco Bay Marine Piling Committee on "Marine borers and thxir rela- tion to marine construction on the Pacific Coa.-;!." (Finures 101 to M5 inclusive opposite page 260) : From data on Plat? 9-8, Vol. II, Bulletin So. 21 "Report on Salt Water Barrier." Division of Water Resources, 1929. Valu"s cf s iliiiity represent the average of samples taken at ten-foot intervals from surface to bottom at slack water following higher hiijh and lower low waters on dates indicated. ' From data of saliiity ol)scrvations in Mare Island Strait furnished by U. S. Navy Yard. ' From data on Plate 9-8, Vol. II, Bulletin No. 22, "Report on S.ilt Water Barrier," Division of Water Resources, 1929. Values of salinity represent the average of samples taken at the surface and bottom at high and low tides on the dates indicated. From records on file in office of Division of Water Resources of salinity observations at pumping plant of Last Con- tra Costa Irriuaticn Company (now Eas;t Contra Costi Irrigation District) near we^t end of Indian Slough in Sin Joiqniii River Delt'i. See Table 33 for records sub^e luent to May, 1923. See Table 34 for records in 1919. ' From data furnished by C. W. Sebedler, Jr., from observations by G^naral Chemical Company. \ 392 DIVISION OP WATER RESOURCES TABLE 35— Concluded MISCELLANEOUS SALINITY OBSERVATIONS, AFTER 1920 Location Nicholls. Nicholls. Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls. Nicholls. Nicholls. Nicholls Nicholls Nicholls Nicholls. Nicholls Nicholls. Nicholls. Nicholls. Nicholls. Nicholls. Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Nicholls Date Mar. 31, 1924. April 7. 1924- April 14, 1924- April 21, 1924. April 28, 1924. May 5, 1924. Mav 12. 1924. May 19, 1924. May 26, 1924. June 2, 1924. June 9, 1924. June 30, 1924. July 7, 1924. July 14, 1924. July 21, 1924. July 28, 1924. Aug. 4, 1924. Aug. 11, 1924. Aug. 18, 1924. Aug. 25, 1924. Sept. 1, 1924. Sept. 8, 1924. Sept. 15, 1924. Sept. 22, 1924- Sept. 29, 1924. Oct. 6, 1924. Oct. 13, 1924. Oct. 20, 1924. Oct. 27, 1924. Nov. 3, 1924. Nov. 10, 1924. Nov. 17, 1924. Nov. 24, 1924. Dec. 1, 1924. Dec. 8, 1924. Dec. 15, 1924. Dec. 22, 1924. Dec. 29, 1924. Salinity in parts of chlorine per 100,000 parts of water 377 1G7 152 97 290 88 197 286 393 543 619 952 1,166 1,126 1,139 1,245 1,199 1,365 1,245 1,439 1,.345 1,492 1,425 1,461 1,346 1,346 645 1,221 1,121 786 680 288 560 345 528 195 538 58 1 Tidal phase Observer High General Chemical Company* Low General Chemical Company* Low General Chemical Company* K flood General Chemical Company' M flood General Chemical Company • Low General Chemical Company. Low General Chemical Company* H flood General Chemical Company* Low General Chemical Company* Low General Chemical Company* Low General Chemical Company* J< flood General Chemical Company* Low (ieneral Chemical Company* High General Chemical Company* Low General Chemical Company* High General Chemical Company* Low General Chemical Company* Hebb General Chemical Company* Low General Chemical Company* Low General Chemical Company' U flood General Chemical Company* Mebb General Chemical Company* Low General Chemical Company* Mebb General Chemical Company* High General Chemical Company* Mebb General Chemical (^ompany* High General Chemical Company* High General Chemical Company* High General Chemical Company* Low General Chemical Company* High General Chemical Company* Low General Chemical Company* High General Chemical Company* High General Chemical Company* High General Chemical Company* High General Chemical Company* High General Chemical Company* High General Chemical Company* ' From dat 1 in final report, 1927. of San Francisco Bay Marine Piling Committee on "Marine borers and th'-ir rela- tion to marine construction on the Pacific Coast." (Figures 101 to 1 1.5 inclusive opposite page 266) = rrom data on Plat; 9-8, Vol. II, Bulletin .\o. 2:2, "Report on Suit Water Barrier." Division of Water Resources, 1929. Valu"s of s ilinity represent the average of samples taken at ten-foot intervals from surface to bottom at slack water following higher Ugh and lower low water.? on dates indicated. ' From data of haliiity oljscrvations in Mare Island Strait furnished by U. S. Navy Yard. ' From data on Plate 9-8, Vol. II, Bulletin No. 22, "Report on S.ilt Water Barrier," Division of Water Resources, 1929. Values of salinity repre.sent the average of samples taken at the surface and bottom at high and low ti.les on the dates indicated. , r, /-. From records on file in office of Division of Water Resources of salinity observations at pumping plant of East Con- tra Costa Irrigation Companv (now East Contra Costi Irrigation District) near west end of Indian Slough in San Joaquin River Delta. ~ See Table 33 for records subsciuent to May, 1923. See Table 34 for records in 1919. « From data furnished by C. W. Schedler, Jr., from ob*ervation.s by Ginsral Chemical Company. TABLE 36 SUMMARY OF COMPLETE CHEMICAL ANALYSES OF WATER AT POINTS IN SAN FRANCISCO BAY AND SACRAMENTO AND SAN JOAQUIN RIVER CHANNELS Date of saiuplc Time of sample Hcsiduo on evap- oration at 110" C. in parte Rf.'' miUion Total hardne^, parts millbn Carbonates Bicarbonates Silicates Iron and alumina Calcium Magnesium Chlorides Sulphut<:» Sodium Station Parts million Per cent of total chemical constit- uents Parts per miUion Per cent of total chemical constit- uents Parte per million Percent of total chemical constit- uents Parts million Per cent of total chemical conatit- uenla Partfi nulUon Per cent of total chemical oonstit- uenta Paris per million Per cent of total chemical constit- uentfi Part* Xon Per ci-nt of totnl chemical constit- uents Paru mSlion Per cent of tola! chemical constit- ucnta Parts per million Per c?nt of total chemical constit- uents Aug. -. 1920 June 20, 1929 8epl, 14, 1020 June 2B. 1020 S-pt. 15, 1920 June 26. 1020 Aug. 30. 1920 June 20. 1929 Aug. 1. 1920 June 20, 1929 June 20, 1929 Sept. 24. 1029 June 20, 1920 Sept. IS. 1929 Aug. 1. 1920 Aug. 1. 1020 Sept. 3. 1020 an. 5. 1030 une 20. 1020 Jan. 5. 1930 Jan. 5, 1930 an. C. 1930 3: 18 "a.m. 10:45 p.m. 5:18 a ID. t2;S5 p.ni. 0:03 u.m 1:40 p-ni. 7:46 a.m. 8:05 p.m. No tide 7:18 a.m. 0:10 p.m. 8:18 a.ro. 5:20 p.m. 11:55 >i.m. 1:47 p.ro. 3:15 p.m. 5:00 p.m. No tide 2:40 p.ni. 3:36 p.m. 4:15 p.m. 33.304 28.304 32.826 0,177 32.370 156 4.437 159 171 145 200 4.640 2Iti 617 114 1.986 1.871 263 261 146 126 176 6.034 5,721 4.947 1,024 456 91 821 87 ISO 75 103 Oil 97 286 77 089 752 140 118 90 70 84 Nil 14 Nil 1 Nil J Trace Nil 12 10 Nil 12 Nil Nil Nil Nil Nil 17 Nil Nil Nil 1 159 105 139 61 116 88 165 98 132 OR 51 116 49 116 50 130 161 03 08 122 73 122 5 4 4 1 5 51 2 3 6 58 3 53 44.3 25. S 2 5 26 3 16,5 428 6 80 26 7 28 4 58 1 44 3 53 3 12 GO 2 426 906 124 121 84 33 84 25 24 37 39 91 35 36 25 232 235 85 211 31 21 30 1 3 3 2 04 1 6 4 10 a 1 8 14 9 7 18 1 19 5 2 18 8 5 1 18 1 11 5 M \i 24 4 10 9 14 8 12 7 13 1 1.212 843 1.131 176 UO ,.5 21 4 167 2.5 48 4 20 40 21 12 3 4 3.6 3 3,4 2.7 03 1 2 3 2 3 6 84 1 3 2 3 6 16 6 8 2,9 1-4 20 6 5 1 4 2 4 3.9 18.200 15.300 17,800 3,000 12.000 20 2.400 16 30 18 44 2.400 46 260 20 1.080 1,060 57 60 10 27 19 53 7 54 8 53 53 3 52 11 6 51 7 9 5 12 1 12 1 22 51 8 24 7 37 18 8 53 5 52 5 16 3 84 48 16 4 8 3 2.510 1.780 2.335 268 1,592 15 320 15 12 8 18 343 IS 03 8 18 12 20 20 4 2 2 25 1 1 9 1 2 11.273 8.983 11.430 2,288 9.168 13 1,502 16 25 1,474 23 133 8 479 449 42 30 15 14 22 28 1 21 1 Boy Point. . . . 35 1 5 5 00 21 is 1 03 Emmaton Emmaton 06 o'o 8"i 5 6"5 7 5 32 4 18 7.3 s 2.0 2 8 Verona....'. . IS 0.4 24 0.5 Bbkes Landing. Venice Uland... 24 2 32 58 27 34 IS 1.6 28 7-7 21 S a 4 4 3.0 4 3 O.S 0.2 1.2 180 7"l 22 2 20 20 20 9 5 12 1 8 7 5 4 5 2.4 2.4 a 2 7 1 9 13 80935— pueee 392-; APPENDIX D STREAM FLOW INTO SACRAMENTO-SAN JOAQUIN DELTA Table Page 37 Daily stream flow into Sacramento-San Joaquin Delta, 1919-20 to 1928-29 394 Basis of compilation of Table 37 424 38 Monthly stream flow into Sacramento-San Joaquin Delta, 1911—12 to 1928-29 428 Basis of compilation of Table 38 430 39 Seasonal stream flow into Sacramento-San Joaquin Delta 432 394 DIVISION OF WATER RESOURCES -o c o u S '^, .S £ „r> CI o *- O gOOOOOOOOOOOQQOOOOQOQOOOOOOOOOO oooooooooooooooooSooooooooSSoS t^-^-^c^oo cc r^c^^'-o o ^^^^^^^^M "-^^s CO '-0 -^ lO cc 00 1^ Qo 1^ 1^ ^^0003030009) O 0<0>03C3030303030>0'0303030000>0>0030) a OOOOOOOOOOOOOOOOOOOi O000000000000000000'__ 2S ooooooooooooooooooooooooooooooo C-OOOOCDOOOOOOOOOOOOQOOOOOOOOOOOO 0_0 0_»0 »0_0 »0 O u:i_0 O O O O O O^O O O O »0 O O O O O »0 lO iC »o »o o'oioTcso'od oToo ooo'oo'qooo'oo'cx) co'oo'oo od od od oo'oo oo' ^os as odooodoooo s i-g ooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooo OO ^— iO Oi (^ ^O OO G Oi ''O Cr> *^ t~^ "^ '-^ OO tr^ t" t^ t~^ t~^ t-^ t-^ t^ t^ iCl^ l^ ^ CJ" t-*' ^^* ^^ t-^ i-^ r-^ t-^ r-^ 1^ ^^ 1^ ^-* t^' t^ -^' -^" t^ ;^ S8g i lO^ O »ft w OS ^« CO t^ o f^ "c 5.13 eg.s § = i fl fl9 O C- V) 3 •- o oooooooooooooooooooooooocoooooo ooooooooooooooooooooooooooooooo I^U5COOOO^'-^'^-^C^0001l^l'^^t^OOl-^t^00000500eC^050SO>Oi 2S oooooooooooooooooooooooocoooooo ooooooooooooooooooooooooooocooo CO CO tC r-T iC co" ^ CO ^' co' '.o* CO co* :o' ;r' 'sC :c *.C cc *^* xo co' ;o cc cc '^ '^ c^" ** ^' CO o a; ^ ^ ^; ^ fc- O t> cj a 09 S •S.S.S OOCJ 2 O) 03 A ' " Ol OS CT> OS c» OS S o <: t L. >- £ o o 2 5 5 o o "S E-HH VARIATION AND CONTROL OF SALINITY 395 -a c o _o ooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooo s ;« OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO ooooooooooooooooooooooooooooooo Oi^Cfl CO CO "M^O CO '— '^O 05 -.C CO r- 0qO5 CO OS C'l to O 05 C'l CO O CO O r- TT 'rj O tM T-4 r-.i-Hi-<^r-i ^^^H^^r-.(MC^-CO:OiOiOTr'^COCOCOCOCOC^'^ .5 E o j2 ^ o :« 25 oooooooooooooooooooooooooooooo oooooooooooooooooooooooooooooo COOOi— '(M(M'*fOOCO(MO'-J«30»0'— lO-'TCOCO^J^t— COM 000000000000000<='OOOOCDOOOOOOOC:>0 oooooooooooooooooooooooooooooo COOCsiiOC^'— 't^'— lOiiOOOSb-O'^'— COCOC^OCr>Oi'-HClOX'"^CO**t'iO OOQ OOO lO o ^ Oi^'^CO r^ot^^ t-^coo" = St. S §:! feci ca (S ® OOOOOOOOOOOOOOOOOiOOOOOOOOOOOOOO 00OO0OO0OC3OOOOOOOO0O0000OOOO0O0 COCviCOCOt'-C^lO'M'— OOOir^^C'OCiOiOCO'rt'C^iOOO'^GO'^OiOOO — GO i-T iQ ic od c4" •-- 00 ^^ ^-^ c^ c^~ o oi" Oi" o ■^' tC ^' cq" csf »o c^cococsjc^O0>OOOO0>OOO0O0OO0OO0O0OC'0C!30OO oooooooooooooooooooooooooooooo© OO0OOOOO00OO0OO0OOC3OOO0O0OOOO 00000000)000000000000000000000 CO C^I CO CO__ '>! 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2S o c 255^^*0^^^0000000000000000000000 ooooooooooooooooooooooooooooooo »OGq ^M C^J^ T!^CT»0-«rTj« OC^OI^OO»—0 CO C^l^O CO ^ '^CT>^'— •C-JCTJC^COiO'^^J'r-C^I'^OcD-^'^ a^ 2g -T3 o o »- o a> a.s c "- o !« a ? 2S OOOOOtOOOOOOOOOOOOOOOOOOOOOOCtOOO OOOOOOOOOC>000000000000000000000 »0'^io»o-^Tj^rtr'^-.^cocococococcccc00000i000000000000000000000 OOCDOOOOOOOOOOOOOOOOOOOOOOOOOOO •^iocOkO-^io»rto»oi^»ou5tDc::;o^»nif5*not^oot^mr-«t>-(OOi^-03 1 M ic in 05 1^ ^ lo ooooooooooooo-ooocjooooooooooooo 00000o00oooc3oc30o00000000o000o0 oot^GOGOaicr-a;ciGOooci'MQOtr'-'c^-Tj<.-»c<»05'^cooo*—or*oiC3(-eD ooo oo o O CO Oi Pi « OJ o c !-• a> a 3 rr ■s s c !ti " C! ti c3 ca o 00000<0000000000000000>0000000000 ooooooooooooooooooooooooooooooo 0C>C;0'0'00000000000000000000000000 ooooooooooooooooooooooooooooooo 0<000 0000000000 000000000 00 0000 00 00O0000000OO00C300OO0000000O000O a CO 3 ooo 416 DIVISION OF WATER RESOURCES •0 u 3 C n tii CQ < z o < tii < H U Q < o z CO I o Z u <: oi u < w O H Z o H to < Q |i o goooooogggoogooooooooooooggogoo s CO OS CO CO San Joaquin River ooogooggggogooogogoggggogggooog CO S 1 ooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooo <» »o cc ^ c^ oi" ;D cc o od t^ t^ oT c^ :o c^r ^ Ci ^ ^ t^ c^ oo r-T 00 o O O rC g CO OS < o O OOOOOOOOOOC:0003000000000000000 OOOOOOOOCOOCIC^OOOCSOOOCOOOOOOOOO co-^r-^rooo^- c:oowo^»c •—^'^ '-C -- ;£:_;0 — CO -oor*b»oo ooooooooooooooooooooooooooocoo OOOOOOOOOOOOOOOOOOOOOOOOOOOdOO oooc^^O»-'^coooo;cicr-r*:i;Od»n^oO'^Ocic;c')c-ir'-CQOO^r''^r oooooooooooooooooooooocooooooo ooooooooooooooooooooooooocoooo CO tOC^ -^CX) :C OOCl^-^ ■^GO-^OO-.CC-J •-^OCOO;<:»i'-^C»-^:£?^iCCi^Ot^OO ^ "^ CO "-^ -^ "^ i~- ■**■ ■* t-- 00 CO o; ic c^i Ci »n ^-aot^!:oiCior^cTicj»nooooc5 c o c 2 o *- o ooooooooooo 0(3000000000™-^ oooooc5ooascoO'-''-'Or-r— :c^rCr-^:c'urr'^-^'^-^'--oot-^r^c^ocioooor-^t^aoo ooooooooooooooooooo ooooooooooooooooooo '-O<^iot^^-C5co0^^coc^u5»or— ^t^^eo rciocioooot^t^aoo-— -—^oo^- ocoi-^ CO s§§ toeo c» osoo t-^ »0 CO OS ^^ ^' oo I o c-E e§.5 llo ooooooooooooooooooooooooooooooo oooooooocsooooooooooooooooooo-ooo ■^0^100^'^:^'^'^0"^'^OOC^O'^^"^OOCD"TrOOOOO'^ ^^'*'l^'^^ ClOOSOOOOt^r-t~-tOC05DeO«OC050tOa5t^sO?CO»CiOiOiC'^'^'^'V^'^' .5 2 1.1 o ^ OOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOCJOOiOOO coo— 't--»CQO'Troo — oor-cocJ*otMO«5t^'^cciO^-ooc<— _;^oo5C ^Ol^O^*od•^os^^O— ^ V O V « CJ u C3 CU rt c c c t^ t^ t— C^ W M OS Ol OS CJ c^ c^ OS OS OS n CO I c^ n rt ■*^ >-> ** o o o VARIATION AND CONTROL OF SALINITY 417 i CO on 09 ^' Q a < o "-J z < o H Z u < o <: w Z o .J b a; H <; Q i i 02 II OOOOOOOCOC^OOOOOOOOOCOOOOOOOOOO 1 OOOO-OO^OOOOOOOOOOOOOOOOOOOOOOO 1 o :c »« r-- oc a; c^ C";^ 1-^ oc 00 r^ o ^ cc '(T ic c» o t-- o -- -^ 'O r-^ w -^ irs GO 00 < I 1 oo 00 OO O O OO O OO O O O O O O O O O O O O C O O O O O O O O I oo o o o o o o oo o o o o o o o o o o o o o o o o oo oo • C3 o 00 o h o o o ooo o c>oo o o oooo o oo o o o CJ oo O O O O O 1 OOOOO OOOOOOOOOOOOOOOOOO OOOOOOO I cj^c^c^i^-00000000>0000000000000000 ooooooooooooooooooooooooooopopo OOOOOO oo I- I>- t-- -JD ^ r^ -JD '-C :C I^ifS tc ^ r-^ ^^ i^^ '-^ "^ "^ "^ — „ ^_ *"^ ' ' "^"T. 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H u 00 t i 1. 33,100 30,900 32,600 34.400 36,300 35,400 33,700 31,500 ■^8000 OOOOOQOOOOpOOOOOOQOOQC oooooogopooooooooooooc "ic V M Ti'^f ■— *c>J— ' o o oC oTcac err o o o' cT o cI 00 c CI Ct -M C-l Tl CI CI CI CI CI ^ ^ ^ ^ CI CI CI CI CI CI CI CC c ll ggooogogogogoooogogooogoooooogg 0'-;CJt— ai^t--x;»c»o«5:cccio:c>uo-^0»o ^^»'^*'^<^!.oo -^^ co co ^oioo c- u^ lO »c rr -^ -^ tt -^ CO CO CO CO CO CO CO -^ ■ 2 u OOOOOOQOOOOOOOOOOOOOOOOOOOOOOOC ooooooooooSoooooooooooooooooooc (MMC^CMcOcOCmMCICvIC^^^-^-*^^^ — ^^^^^^ — -^^^C^CS § CD 3 CO a Q o ooooooooooooooooooooooooooooooo o ooooooooooooooooooooooooooooooo o C'j^^^^^^^^^^^^r-.^csc^ — ^^— .»-i^w^C -^ CO C) C^l CI •-- —^ '^ »^ a -s 5 " 'n a> a-g o oooooooooooooooooooooooooooooo C=)OOOOOOOOOOOOOOOC500000000000c:>0 lOt^^cOl<^^c^cx)■*^-r-c^u^co!^aDlJOt-^'^lq;o^'yDc-Jcooc .-4" ^ ^ ^" ^ ^ o ■^ -^ --^ c^ in t-^ c^> c^*' O -^' o' ic tt t--r CO CO •— ' oT " cc t~ CT o ^^<^> <» i-^co c^a5 -^co ^00 c^M CO CO ■*»• M »--« CO odooodcs<^aroicicriooCTi05aiCscio:ooodooooc g to •3 ^ CO oooooooooooooooooooooooooooooo© oooooooooooooooooooooooooooooco ic CO oo 00 o CO CO -— ^ .^^ c^_ c i_ CO ■'T »c »o »o »o_ -^r u:j_ :o CO -^r -'T ^ ..^ ^ ^ c^' ca c^ c-J ci CN ci ^-^»rtOOool--^o^CT^^•^^*^-ooc'iC5^— cocDcDcocDcoco"cococOcoeot-^'•^-oco cocOcocccD cocococct-^r^"i^r^oo o o cJ CI (3 - WK ^ •dtc t^OOCT 1 .s 1 ^1 OOO ooo OO 00 o ofiood I-— iGO cooo ■^ r^co^ Ss s u c g OS ca o cctcO V V V ^ ^ 0) COB OO 00 oo M c^^ c^ 0> OS Od C^ « C4 ■*^ -ii -t^ OOO VARIATIOX AND CONTROL OF SALINITY 419 0^ z o w <: u CO Q O o I o H Z < u o H z O b <; u 05 H w nJ a c o o E o "- O o > Id eg 2S o ■- O ooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooo o ooooooooooooooooooooooooooooooo oooooooooooooooocoooooooooooooo ooooooooooooooooooooooooooooooo OOOOOOOOOOOOOOOCIOOOOOOOOOOOOOOO 1^ O o '— ^- r>t — o — ~ ■-:: cr. — ^- c^ c; — re c^ lO O ■«r cc :c o O — ^- •n 'J •— • ooo ooo oooo o r- <— GO ;D GO -^ ooooooooooooooooooocoooooooooo ooc^ooooooooooooooooocooooooooo ooooooooooooooooooocoooooooooo O0O00O000O0000C3O00O00000OO00OO lOcot— ooocijr-oo— •aoootot--ir;i0i0rrc50c^'^«— "00'^coooo;S"*0 oooooooooooooooooooooooooooooo oooooooooooooooooooooooooooooo l>.OiOOCl'^'*»-'^C-J'^'--t^»-''— 'rr.;C!;Dt^dO — c<»-r*t^ OOOOOOOOOOOOOOOOOOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOO »-«C^C0'*»0?0b-000iO»-*C o o 0» 0/ a; V ooooao c^ rt ^ Co ■*A ■*» «» OOO 420 DIVISION OF WATER RESOURCES "0 u 3 C J < 00 IS ON z O < w <* H I-] W Q P < O I O H Z u u <; w o H z O 1^ < a H CO Q a D. C o o o o O c a-! o O c CO « a.g o O > OOOOOOOOOOOOOOOOOOOQOOOOOOOOOO oooooooooooooooooooooooo oooooo t~-00O"— "'— 'CCiM'^iOOO'— 'COt--0:DlOOiCtO'^iOiOiO»^iOtCi':D oooooooooooooooooooooooooooooo© ooooc-oooooooooooooooooooooooooo ooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooo t^t^t— t— aioooot^t^co»oi>-^cocDcocoot^«cit-»cotc:c^t^r-t^t— r^CT) ooooooooooooooooooooooooooooooo OOOOOOOOOOfOOOOOOOOOOiOOOOiOOOOCSOO — o ^' '-iJ I -• c:i CO >n c^i •— ' O 1— ' CC c.tDOiO-<*<(M OO0OOOOOO0OOOOOOOOOOOOOO0OC3OO lOCOr-t'— iCOCCCDt— CCCCO^n*— •O'OCOt^COCaOt^t^OOcO'^CiOOt— oo O 00 CO O CD O ^ M »--r ^-T O O oT O Ol 00 OO l>r t^ t^ W CO ?0 CO CD OOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 000i000000000<300000000000000000 cct-'^oico(MOsco»— 'OiiracoooiocO'—ooioo t^t- cocccccO'*'«!»'cc'^eo^ oT t^t^co t^t-^ift Tt^-^cc co"co cXc^c>f c^ c^,-i,— i,— .T-iF-iosecooc^ioo-^0'XiTt"ooi-t--:oi^'*ccoooo»oirO'--— >c-ioo»c»cccio <-n"o o"os"o5"o6"oo oo"t^t~- cd"cc*o"cd'cd cd'co *o »c»o»oicif5icic»0'^'tr'^'^ o H CJ o r> o ci) A r> C3 C3 C3 a C C oooooo CT- OS 0> <— ' •7" 1—1 z «: w I O H Z u < a; o < o H Z o H c o ooooooooooooooooooooooooooooooo oooooooooooooooooooooooooocoooo o o 3 ooooooooooocoooooooooococoooooo ooooooooooooooooooooooooooooooo ■^co ITS i>^-j:;_»/^o tc^tn »rt - ci cc o ■-:: -^ -^r ^- o tp oo irj ^ CO CC ci" ^ '-H ^ Cf C^ C^ :rC GO QC QO" OC GO 00 c; si" o' — cT o o ooooooooooooooooooooooooooooooo OOOOOOOOOOOOOOOOOOOOOCDOOOOOOOOO i-HCO^MinOI>^C5CO t--CCCO'--^C^OOCC»-^COC005iOOlr^^Oif3'»'-^0 CJ^'^ 'S V © ^ •^5 ooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooo ■^■^r-^iOCOt^t— OOOOOOOOOOOOOOOiOOOSOOlO'^CC-^^C'^-^iO'n'iO c4" c^ c^ o^ CI c 25 ooooooooooooooooooooooooooooooo OOOOCSOOOOOOOOOOOOOCDOC^CDOOOCOOOOO ^eO;DcCcC^t-^^^I>^!£^000•<1^•-oot^ioO"^»ot^oo;3t--c<'^iO*r3'^comTrio^oooor-*-i CO to I>- t^ t- t^ t^ f- ^- t~- t^ ^ f^ "^ t^ t^ ^ ^ ** oo 00 ^^^—i --.-1— --H^-i— 1— ■— '^-'—'-''MCiOC^C^dC^CQC'JCvlC^C^C^dC-ld ooooooooooooooooooooooo; oooooooooooooooooc;ooooc:: S»C t^ t--_i^^~^_O^0 C: t-. :ri_i- t-OC ^._-^ t- O — -ri^— — =^, — . ' tc ic ifa" lO »n to "^ o lO ic in 1.0 »c ic ^ ic lO -.o -— -^ — — -x -^ : : -^ "O "O ;0 O f-lNC*3^»0«©t^OOCSO'-'WCO'^O^Or-OOC50-^C': ec-^-uacot^oociO — cqc^c^cflc^c^c-ic^c^wcce^ OO o ooo CC C-J o ,—*■«■ ci C^ U5 t>- C3 C3 O o a> a; «M Vh t^ 0> CI cs C^l C^ CI ^ Oa CA obc >aooo Ci dCl ^ 03 93 OOO 422 DIVISIOX OF WATER RKSOURCES •s 3 .s K Hi CO < ON c o OS S .s e ggggooooooooogooooogoogoogogoog 1.259,100 h 03 CO ggggooogooooogogooggoooggoggggg CO ■^ OOO — ^cr c»:i -JD o-M »n ,© i^ i- i-- i- oo c-i i- o O O ct_ cr; — ;^o --^oo lO t c4" c^ CO eo ec CO c^* c^r c^ cc cc CO CO cc cc cc CO cc ^ ■*' ic -^r TT -^^ «5 ?3 eg ooooooooooooooooooooooooooooooc OOOOOOOOOOOOOOQOOOOOOOOOOOOOOOe r- r-- t^ 00 "C O --^ t^ lO OS -<** T-*^ O CO O CO t-; Oq O --^ Ci 00 CO cr^ « OiOO'-^'-^^CrOiCTiOOodoOGOOOOOOOOOodcOt-^cO'^-^^ 8 CO .S 2 o *- O OOOOOOOOQQOOOOOOOOOOOOOOOOOOOO oooooooooooooooooooooooooooooo '«rl^t^ooScoo^-:^Sooo^'-^J'o^t^So■^»rt0^^co^ClC^^^5coco^_^/5 00 "B gggggggogoggoggogggogggg§og§g| --" .-1 ^ c^' <^f c^" ri" (M CO c^' <^f ir4 M c^" c-> c^ c^" c^ e^ c ^O C^^iC ooo -^c-i o ^c^_-^t^o> ^'-H(McoiO"^»o-*r-«r'*eococ^^^--^'— ■-'•-''-"^'— ^ — ^•-*^ i CO a "5 gggggggggggggoggggggggggoogg COOi'--:DkOC'ltCO'^COC^OOOOSGOI^ia5iO»Oinu^uO^COCO»-^0 C^ciTPI^';DiOTrTl^COCOCOcOCOCO':^C^C'f(>JC^C^ o g o oo 2 g I. is: gggggoggggogoogggggggggggggg s CI n -H oj « ■*' u> CO t^' W oi o — ' M m •♦' "5 ffl 1-' 00 oi o -- M M •* « o r-^ CO 05 o M •si k C 1 ggg CO C^ If 3 c^ lO r- ■^ »0 OS a§-s fe eg c3 ca o coccO Jacob •^ -*« «^ o o o " VARIATION AND CONTROL OF SALINITY 423 0^ 00 0^ z o < Ui < Q < O I o H Z u <; oi u < o H z O u 05 H <; Q •a c o Combined rivers oooooooo oooooooooo ooooooo ooooo . O OO O O O O O O O O O O O O OO O O O O O O O O O O O O O ' CO eo a o > o oo o o o oooo o o o oo o o o ooo o o ooooo OO t o ooo o o c>ooo O O O OO O O O O O OO O O O O O O O O 1 tocD-CCit^t--t^cC'I^t^OOOOQOt~-CDr^OS_«-^'-^ o o 1^ 1 3 1-5 o •- OOOOOOOOOOOOOOOOO'O'OOOOOOOOOOOOO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO lO iC '•l^ iTi -"l^^ 'Tt^' '^r (?0 CC CO CO CO CO « CO ^ g CM C<1 eg ooooooooogoogoooogooooooooooogo CO CM CO -2 It ooooooooooooooooooooooooooooooo 00001300000000000000000000 -^OOOOO io53Sooo!o«S oi(»oo t-t-a3^-o-*-*Tr co>otocor^t~_t-^oo_ait-.oo ■^ -^ c^ fo M CO CO CO c^f c-f cr (^^ c^ c^ c^ c-5 1. OOOOOOOOOOOOOOOOOOOOOOOOOOOOOO ' OOOOOOOOOOOOOOOOOOOOOOOOOOOOOO ' c^ o oi S CO o tS o-^ --_.oo_ --<•«•_ oo«csx>_^-^ c-|--_O05 0)C^_o c^_oo CM. t^_cn — _o_ o_^_-^_c-i_—_:o i-_o.oo_(M_t-- ira lo co_co_co | c7c^i"c>icT .-^'-^^c-icroi c-f c-i c^t c^ic-fco -^tc ITS rr CO CO c>f rf ^-^-^.-^^^ ; g Is r s§§§§s§§sg§§§s§ssss§sgs§s§s§s§ i Ooot^^■5*coc^lC^lC^ooo^cooqocto©*c^•oco05.— ©cor^c^ • g OO S5 Jc^c^^«»t^«;a;o-;^co2:22^22g?igis3s;^gsssg;; i k ooo ooo CO CM to ^^CM CM lO t^ "^ lO OS o S "^ a §J fe c H 03 it i> ^ a % QOOOOO CM C-1 CM OS cs OS tn vt n t k. h. •2 ■*» -^ ooo E-E-H 424 DIVISION OF WATER RESOURCES BASIS OF COMPILATION OF TABLE 37 (See Plates I and II for location of gaging stations) Sacramento River. , The daily stream flow of the Sacramento River into the delta was compiled from the following stream flow records and estimates. 1. Sacramento River at Sacramento (used only when the flow at Sacramento is unaffected by tidal action or is 24,000 second-feet or more). (State and U. S. Weather Bureau Records.) 2. Sacramento River at Verona (U. S. G. S. Records). 3. Sacramento River at Knights Landing (U. S. G. S. and U. S. Weather Bureau Records). 4. Feather River at Nicolaus (U S. G. S. and U. S. Weather Bureau Records). 5. American River at Fairoaks (U. S. G. S. Records). 6. American River at 11 Street Bridge (State Records). 7. Yolo By-pass at Lisbon (State Records) (used only when the flow at this station is unaffected by tidal action). 8. Cache Creek at Yolo (U. S. G. S. Records). 9. Putah Creek at Winters (U. S. G. S. Records). 10. Estimate based upon U. S. Weather Bureau and State Records of single daily gage height at Sacramento and Lisbon, combined with a comparative study of the total daily flow at upstream stations near the rim of the valley. 11. Estimated net diversions below gaging stations and above Sacramento (based upon records in reports by Sacramento-San Joa- quin Water Supervisor, 1924 to 1929). 12. Records of net diversions from measurements of Sacramento- San tToaquin Water Supervisor (1924 to 1929). In general, the total combined flow of the Sacramento River into the delta was compiled from the records of the farthest downstream stations available. Thus, (1) and (7) were always used when the records were available and tlie flow at these stations is unaffected by tidal action. When records at these stations Avere not available, or could not be used on account of tidal effects, the best records available at stations immediately upstream Avere used. Thus, when (1) Avas not availalile, the floAv of the main Sacramento River Avas compiled from the sum of the f olloAving records : 1919-20 to 1923-24, inclusive— (3), (4) and (6) or (5) less (11). 1924-25 to 1928-29, inclusive— (2), (6) or (5) less (12). Similarly, Avhen the flow at (7) Avas low or affected by tidal action, the flow in the Yolo By-pass into the delta was compiled as the sum of (8) and (9) for the entire period 1919 to 1929. During the periods of large Avinter floAv from 1919 to 1923, inelu- si\'e, the records at (1) and (7) Avere incomplete and inaccurate and no Avinter records were available at (3) and (4). The Avinter flow VARIATION AND CONTROL OF SALINITY 425 during this period of missing records at (1) and (7) was estimated from relations established on the basis of comparative hydrographs of flow at upstream stations near the rim of the valley and at the lower stations for the period 1923 to 1929 when records at both rim and lower stations were available. San Joaquin River. The daily stream flow of the San Joaquin River into the delta was compiled from the following stream floAV records and estimates : 1. San Joaquin River at Vernalis (U. S. G. S. Records). (This record was available only during the periods of small discharge and was always used when available.) 2. San Joaquin River at Newman (U. S. G. S.). (This record was used only when the Vernalis station record was not available.) 3. Calaveras River at Jenny Lind (U. S. G. S. Records). 4. Mokelumne River at Thornton (U. S. G. S. Records). (This record was only available during 1929 and was used in preference to Woodbridge or Clements when available.) 5. Mokelumne River at Woodbridge (U. S. G. S. Records). (This record was available for low water periods of 1924 and 1925 and for entire period from 1926 to 1929, inclusive. This record was used in preference to the record at Clements (6).) 6. Mokelumne River at Clements (U. S. G. S. Records). (Used only when both Thornton (4) and Woodbridge (5) records were not available.) 7. Tuolumne River at La Grange (U. S. G. S. Records). (Used only when the Newman record (2) was used.) 8. Stanislaus River at Knights Ferry (U. S. G. S. Records). (Used only when the Newman record (2) was used.) 9. Cosumnes River at Michigan Bar (U. S. G. S. Records). 10. Dry Creek at Gait (U. S. G. S. Records and estimates). 11. Diversions below points of measurement and above delta. a. When Vernalis record (1) was used the following records and estimates of diversions were used. 1. By delta uplands below Vernalis (Records from 1924 to 1929 were from measurements by Sacramento-San Joa- quin Water Supervisor and previous to 1924 were esti- mated based on those records). 2. From Mokelumne River (U. S. G. S. and Woodbridge Irrigation District Records). (When Thornton (4) and Woodbridge (5) records were used, no correction was made for this diversion.) b. When Newman record (2) was used, the following records and estimates of diversions were used. 1. By Modesto and Turlock Irrigation Districts from Tuolumne River (U. S. G. S. Records). 426 DIVISION OF WATER RESOURCES 2. By Oakdale and South San Joaquin Irrigation Districts from Stanislaus River (U. S. G. S. Records). 3. By delta ui)lands and from main San Joaquin River belov^' Newman. (Sacramento-San Jpaquin Water Super- visor Records, 1924 to 1929, and estimates from 1919 to 1923.) 4. From Mokelumne River (U. S. G. S. and Woodbridge Irrigation District Records). (When Thornton (4) and Woodbridge (5) records were used, no correction was made for this diversion.) « 12. Estimated return flow below points of measurement and above delta. a. When Vernalis record w^as used, the following return flow was estimated : The total return fl.ow from the Oakdale, South San Joaquin, Modesto and Turlock Irrigation District diversions was estimated as being 35 per cent of the total annual diversions, and for the delta uplands and lower San Joacjuin River as being 15 per cent of the total annual diversions. This total return flow was segregated monthly as follows: Monthly Bctnrn Floiv in Per Cent of Annual Return Flow Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Ill 7 8 11 12 10 9 8 7 7 For the IVIokelumne River the total return flow was estimated as being 14 per cent of the total annual diversions and segregated monthly by computing the return flow of any month as equal to 14 per cent of the previous montli's diversions. -A '■f I- k 1. From 75 per cent of diversions to South San Joaquin % Irrigation District. ** 2. From delta uplands diversions. 3. From Woodbridge Irrigation District diversions. (When Thornton record -was used no return flow was estimated.) |^ When Newman record was used, the following return flow was estimated. 1. From Modesto, Oakdale, South San Joaquin Irrigation District diversions. 2. From 85 per cent of Turlock Irrigation District diver- sions. 3. From Woodbridge Irrigation District diversions. (When Thornton (4) record was used, no return flow was estimated.) 4. From delta uplands and lower San Joaquin River (below Newman) diversions. I >• VARIATION AND CONTROL OF SALINITY 427 In general, the total combined daily flow of the San Joaquin River into the delta was compiled from the records of the farthest down- stream stations available. Thus the total sum of (1), (3), (4) or (5), (9), (10) and (12a), le.ss (11a) was alwaj's used when the records were available. When the record at (1) was not available, then the total sum of the following items was used: (2), (7), (8), (3), (4) or (5) or (6), (9), (10) and (12b), less (lib). 428 DIVISION OF WATER RESOURCES 00 n U < 0^ 00 o H I H U Q 3 C •< o z < I o H Z <: a; u < o H Z 2 I OOO Sg§ fgg OOO ggg O CO M ggg goo ggg ggg oSo _ a O 1* 'T to O »o »o »o o ^ ^ -M coo to O cc O ooo C^) 00 o d -V PO oo ooo t-*O00 — 3>o r-r^-"** o oa kC C^ — ' ^' H^ t'- *.-D f^ »C t^ CI oo r:oo I^— o ooo o — — ■«• -^o ^-Cl ■* n ^tn ■»3>- 00 O lO QOOOO t~OT c -r ir ^C CO o t^cc o - « CO ^»« C^ CO Ci — CO -^ e« — oo — OCO CO c^ — -w 03 e<5 •>»< CO -^ CO •* CO -^ CO CO M CO M M ooo OOO ooo ooo ooo ooo ooo ggg ooo ooo OOO ooo ooo coo ooo ooo ooo OU5 10 ooo O => =5 o — — osoot^ 3 < C5 00 t^ t^ — 00 «3 OU5 ^- oo OS lO -.c — lo -^-^ ■^■^ Cs CIM40 -0«05 <^^c^l -"I" I^*OCO ooo iO »c — »0 CO 00 »c -^ t* ■^c^ o iC lO Tr TP •a>— .lO •» to CO — I- CO T o a l\ ooo ooo ooo CO oi"r^ or* 00 ooo ooo O CS Ci ooo ooo OOO ooo O 00 00 o -^ -^ ^cs z^ '-^ ^■^iCs' I— 00 O — ■ -^ lO t^ 00 O 00 to CO ooo ooo lOC-f 00 O :0 CO f- *o w OOO ooo O 3i OS •V eooo »o ■* as OOO ooo O 00 00 osffTod CO r^ ^< OOO ooo o t^t^ ■^tDO Ci C^ r» OOO ooo ooo r-^co o ^ ^ CO ^ e4" ooo ooo o en ^ cT— o o lO -^ t-<(M CO OOO ooo 0:0 OOO ooo O c^c^ ci" as" ^ OS 00 r^ *—. CO »0 ■^ .— I :D to E^C4 00 oo CO ooo ooo O CO CO coo CO c^j a; ^- tO ^o ooo o oo o oo oo odoTi^ ooo Oi OO OO CO ooo ooo o -^-^ 00 00 CO CO OOd ooo ooo o»« »o COC4 00 COC4Q0 ooo ooo CO CO C5 : o o o c^ :■■: CO oo ^r ■^ CO ^- o t^oo CI to t^ cr-— o to tO -^ CO O CO — r- oo lO t— 0 t^ CO O I-" ^t" o -^ era 00 r^ OS O ooo OOO Occco_ cC»o -^r ^^ O C^l Oc^^c^ OOO ooo O CO CO tOt^C-f — CO to "Tf O ^9* ooo ooo O cO_ CO •^cO O to CO c^ CO CO Oi ^J" »0 OS b- Oi O ooo ooo to -V Oi U^ 00 CO O — ' c^ ooo ooo o n_ c^i^ as oto cs oo 00 ^^ CO oo ooo ooo ^- to CO ciooo oo o to (O CO '-'.-« CO ooo ooo ooo OOO ooo OOO ooo OOO ooo ooo OOO ooo ooo ooo ooo O CO CO O CO CO o o o ooo OCO CO OCl CI 00 -"J-CI o — o COI^ — OC-lC^l o — O OCO CI lO >ra '"' ^^ ^H O-^C^ — O) co-^ »o ^^ 1-1 ^- ooo ooo ooo ooo ooo O CO CO ooo ooo O_co_co_ ^^ ^* 00 o -^ r^ CO — -^ ooo ooo OCO CO ooo ooo ooo CO r^o OCl CO r^ ^H c» OOO OOO c_oo oo ci'o oo r^ CO — CI -^ ooo ooo OCO CO ■^00 cT — *c r^ ooo ooo O CI C4 r-Tco o •* 1^ CI CO — 00 ooo ooo ooo CO O CO CO — r^ > o >5 §oo o c ooo — "oo" TT ■— — in o ooo ooo o — — ooo ooo ooo ggg ooo ooo ooo o_ o_ o_ oo QO O O -"J* — ' tn CO OOO ooo o_ o_ o_ 00 co" — -^ -^r o o — r- ooo ->oo »oo »n t^ *0 CI ■V in Si ooo ooo O o CD CO CO O g cic^ OOO ooo CO CO o y m . ill ooo coo Ol^l- §11 OOO ooo Ooo ooo OOO o »mo ggg OCO CO ill ill iii CO CO o Clio r^ OOU5 •«J«CO00 « M5 CO — -a. — CO -^ or^co OIOCI CO CI in CI •»»■ o o o CO OCO O OOOO 00 toco Oco '•J' O ■a» -^ m cr — m — t^ CO OCO ci-^r CO CO -v 3 o CO S-.i Cfo >.C t • QC— -^ ifii— *^ ISC'— '^- I - 0.5- i2 o ^ I I i* i- cn^ 4 CD .». g c: = — '3- S 5 S._ = o S o — o> C3 O tte o- o ' c^ — ^ ^ - - . ! '^- ->■- ^ § v; ■■<• w g CJ 3 CO = o i . C ■ c c [CCK^g'. i 1.1 VARIATION AND CONTROL OF SALINITY 429 ooo ooo I^ CD CO oi"oo »-" r-^ C5 C^ CO ooo ooo OS cTos t^ »n c^» C^l CO CO ooo ooo •O O lO ooo Oi ■^•^ to ooo ooo h- "^J» ^ c^co to CO 1< t^ lO o »o ooo ooo ■^<0 O ^* ^T Oi CO OO M* t^ XI ■*»* ooo ooo t-^O t-- ococi coor^ Oi lO ^ ooo ooo o ro C5 C^ C^ Lfi lO *c o ^ ^^ (M CO ooo ooo OO CO ^ l^ — 'OO CO 00 ■^r rCcc — ooo ooo CO c^)^*o c^ kO r* •^ »o c?> o c-o ooo ooo ooo OOO ooo ooo ooo ooo ooo ooo ooo ooo CO lO — ' CO ■«*• o 00 c^ o ococo ^-^(M iOi-« CO ^ ot- t^ IC CO O C^ CO lOOO Tji OO ^ OS COiC OO OO ^ Ol CO O CO i?^!::: ^ 00 o CO !M GO i^coo CS CO CO ■* W CO - 31 t- rr — ■ I^-M Ci CM CO ^^ C-J C^ «M T-. c» OOO ooo ooo OOO ooo ooo ooo ooo o oo> ooo ooo ooo ooo OOO ooo ooo ooo O tT CO OO OO ;0 (M O Oi l>-Oi Oi c^ o *— C^ OO o O '<*' o 00 CO ^ (M OCO OO ^ iOc^ T-. locm^ OOtO-^ ^ r^rp r^ — OS -^kOOl CO CO t^ ooo o o o> ooo OCOOS C50CS t---in05 TTiOOS oirs— <" cococD ■rr'^oo" c-itriTji" ooo'od" kO'-'co cooo*— ' ooo COiOOO CO C*l_ -^C^JCO 10.-HO ,_( t-- O -^ CI '-H CO ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo cOrf O o-^_^o '-^CO'^ ^CI^CO OSCiOO CO O CO ooo '^ t^ •* C^ t^OOO Tf OO CO CO I^O ■^-^in 00 lO'* o CO ci" --^GO O CO to CS CO -^ 00 O OSiO '-' CO lO CO CM »n 00 OS t^ moi OO t^ ^ OS OOO UOl'-^CM CM ^CO »o t^CI^ in CO — _ CO to -^ ^mto m^.co^-H_ '^'^-.'^ osr- o ca-^'^ ':0^iJ^ OO osoo CM CO oT '<»' CM t-- ^-^lO -^t^-Tcf tC-S-v CO Cl CO COOO lO '-' CO lO CO CO O O t^b- »— t^ 00 mTji OS CM OS CM ooo OS O '^J'-^J^ i^c^»o OOO'* T-CM-* in »n cj CO m mcM t>- ^ COOO TT OS CO o-<-^ CO -^ C^CM OS CO to-^jT CM~Oci -^cooo CO coo ^CO '^ -^o '«r OCOO eo-^O lO CM t^ CO ^ in CO l^ CO OCOOS or^GO ^oo O 00 OO O CO t^ CO^iO O'^'^ ^^C-3_ OS CO CO CM^com CO OO ^ CO CM CO C|«CO •^ -^f c• CM CM in CO c-i m CO -^ OO '^r i-o" 1—1 1—1 ^ cf •—1 cI" cf 1— ( 1— « ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo OOO) CO o o> ooo O O CO CO O CO I^iOCM ■^TT OO TT — in ^TT m OCJ CI OCOCI_ '-_OS^C5 oT^o OcfcM CO c-i"oo oo'cfo in CO CO O -^-f -"^cf-^ mom ■^com OO -^ CO CO'^J' OO CO moo CO •-< in O I^ OO CO OCl Ceo CO -^ CO o O CO CO r-co'^ OCMCM^ ^:o t-- ^^ in OSi-H c? CO^OO CD CM OO O CM CO tO^-ib- CO -^ 1-H .— « . CM CM '"' CM CM »— 1 .—1 o> o o ooo ooo ooo ooo O OO OOO ooo ooo ooo ooo ooo ooo ooo OOO ooo ooo ooo ■^ OS CO r- ■* ^ CO »n OO ot- o OO CM O CO CO OS I"- CI OS mom W OstO oToooo lO-^O O-^-^J^ CO'CM-OT com OS cr-^ CO CI m r^ oTiC-^ I-^OOO CO to o COiOCM CO -^ O O OS Cs t-« 00 m ■'T OS Oio m mco OS o m in OOi-H o -^ lO CO -HCO -i*. -^ CC-Ht^ -*»< »-i m — " ^Cl »-;^CM CO m-^ CO ^ ci i-H *-H T— « •— 1 ooo ooo ooo OOO ooo OOO OOO OO o ooo ooo OOO ooo ooo OOO OOO ooo ooo co-^t^ ^^^lO I— 00 cs ■^ ■-. m 00 0-* o O OS OS '^CO t^ ^o— _ CO O CO od^oi" 00 iC CO 00 CM O -* o-. c^j cocor^ ^OCM OS to CO CM -^r CO CO CI 00 T»« tfi CO -'S* % •^^to CO CO ^^m CO -**« •^^•^kO co^-^ r- >.2 £CJ >.S. t a 3 ct «M , o CD 5-5 "5 = 1° 3 O 05 3U a >.2 Eio >.S Cto ■;;-_, en - ~ — 5 as o.S'i ^ = - II '•^ C- PJ -^^ ^ OJ C-— o B 0-— o «= e 5 =*e e ^ C»^ CJ o B'CcM c a K o c loa -=-:: ^ rJ-^-S ,- =s-^-2 S"SJi3 3 O OJ 20 s 5 c 730:; 2 3 c g o S r3 O cfl rt CO = 5 4;50 DIVISION OF WATER RKSOITRCES BASIS OF COMPILATION OF TABLE 38 For period 1911-12 to 1918-19 (See Plates I and II for location of gaging stations) Sacramento River A. Tlie niontlily stream flow of the Sacramento River into the delta duriny,' the winter period from November to March, each season, was compiled from the following stream flow records and estimates. 1. Ilydrographs of the combined daily flow of the following rim stations having a continuous record were compiled : a. Sacramento River at Red Bluif (U. S. G. S. Records). b. Feather River at Oroville (U. S. G. S. Records). c. Yuba River at Smartsville (U. S. G. S. Records). d. Bear River at Van Trent (U. S. G. S. Records). e. American River at Fairoaks (U. S. G. S. Records). f. Cache Creek at Yolo (U. S. G. S. Records). g. Putah Creek at AVinters (U. S. G. S. Records). 2. Hydrographs of the total daily flow of the Sacramento River into the delta were then estimated from the hydro- graphs of combined flow of the rim stations compiled under item (1), based upon the relation established between the flow at the rim stations and the measured flow passing Sacramento and Lisbon (Yolo By-pass) from a study of comparative hydrographs compiled for the seasons 1923-24 to 1928-29, inclusive, when records at both rim and lower stations were available. As a check on this method, all available records of the single daily gage heights at the Sacramento and Lisbon stations applied to the rating curves at these stations, were used as a guide to estimate the daily flow during periods of large discharge. The monthly stream flow of the Sacramento River into the delta was compiled from the summations of the estimated daily flows taken from the hydrographs compiled under Item (2). No correction was necessary for diversions or return water under this method. B. The stream flow during the period from April to October, each season, was compiled from the following stream flow records and estimates. 1 . Records of stream flow at the following stations : a. Feather River at Nicolaus — U. S. "Weather Bureau gage heights applied to State rating curve. ' b. Sacramento River at Knights Landing — U. S. Weather Bureau gage heights applied to State rating curve. c. American River at Fairoaks — U. S. G. S. Records. d. Cache Creek at Yolo — U. S. G. S. Records. e. Putah Creek at Winters— U. S. G. S. Records. 2. Diversions and return water between these stations and Sacramento were small in amount during this period. No corrections were made for such amounts, except for the VARIATION AND CONTROL OF SALINITY 431 season 1918-19, when a deduction was made for estimated net diversions. San Joaquin River The monthly stream flow of the San Joaquin River into the delta was compiled from the following stream flow records and estimates. 1. Stream flow records at the following stations: a. San Joaquin River at Newman — U. S. G. S. Records. b. Tuolumne River at La Grange — U. S. G. S. Records. c. Stanislaus River at Knights Ferry — U. S. G. S. Records. d. Calaveras River at Jenny Lind — U. S. G. S. Records. e. Mokelumne River at Clements — ^U. S. G. S. Records. f. Cosumnos River at Michigan Bar — ^U. S. G. S. Records, 2. Diversions below points of measurement : a. From Tuolumne River below La Grange — U. S. G. S. Records. b. From Stanislaus River below Knights Ferry — U. S. G. S. Records. c. From main San Joaquin River and to delta uplands below Newman (estimated). d. From Mokelumne River below Clements — Woodbridge Irrigation District records and estimates. 3. Estimated return flow from the following diversions : a. Oakdale and South San eJoaquin Irrigation Districts on Stanislaus River ; Modesto Irrigation District and a portion (85 per cent) of Turlock Irrigation District on the Tuolumne River. 1. For the above annual diversions, the total return water was computed as being 35 per cent of the total annual diversions and distributed as follows : Monthly Return Water in Per Cent of An^ival Return Water Jan. Feb. Mar. Atn: May June July Aug. Sept. Oct. Nov. Dec. Ill 7 8 11 12 10 9 87 7 b. Delta Uplands and Lower San Joaquin River below Newman. 1. The total return w^ater was computed as being 15 per cent of the total annual diversions and distributed as above in item (a-1). c. Mokelumne River Diversions. 1. The total return water was computed as being 14 per cent of the total annual diversions and dis- tributed as follows: Monthly return water was computed as being 14 per cent of the previous month's diversion. The monthly stream flow of the San Joaquin River into the delta was compiled as the sum of items (1) and (3), less item (2), 432 DIVISION OF WATER RESOURCES TABLE 39 SEASONAL STREAM FLOW INTO SACRAMENTO-SAN JOAQUIN DELTA - Seasonal stream flow in in acre-feet Seasonal stream flow in per cent of 58-year Mean Season Sacramento River San Joaquin River Combined rivers Sacramento River San Joaquin River Combined rivers 1911-12 11,795,000 13,581,000 34,176,000 28,874,000 28,763,000 17,690,000 10,020,000 16,422.000 7,730,000 25,720,000 18,279,000 13,406,000 4,533,000 16,764,000 12,970,000 25,460,000 17,673,000 7,422,000 23,449,000 23,442,000 18,228,000 14,995,000 16,058,000 2,515,000 1,701,000 9,909,000 6,970,000 10,192,000 6,916,000 4,170,000 3,649,000 3,014,000 5,771,000 8,350,000 5,188,000 •1,043,000 4,685,000 2,503,000 5,438,000 3,816,000 1,551,000 7,897,000 7,805,000 5,537,000 4,136,000 3,599,000 14,310,000 15,282,000 44,085,000 35,844,000 38,955,000 24,606,000 14,190,000 20,071,000 10,744,000 31,491,000 26,629,000 18,594,000 5,576,000 21,449,000 15,473,000 30,898,000 21,489,000 8,973,000 31,340,000 31,247,000 23,765,000 19,131,000 19,657,000 50 58 146 123 123 75 43 70 33 110 78 57 19 71 55 109 75 32 100 100 78 64 68 32 22 125 88 129 88 53 46 38 73 106 66 13 59 32 69 48 20 100 99 70 52 46 46 1912-13 49 1913-14 141 1914-15 114 1915-16 - 124 191B-17 78 1917-18 45 1918-19 64 1919-20 . 34 1920-21 . - 101 1921-22 85 1922-23 - . 59 1923-24 18 1924-25 68 1925-26 - 49 1926-27 99 1927-28 69 1928-29 29 58-year mean 1871-72 to 1928-29- 40-year mean 1889-90 to 1928-29. 10-year mean 1919-20 to 1928-29. 5-year mean 1924-25 to 1928-29. 100 100 76 61 63 t 5 I GLOSSARY 28—80993 GLOSSARY DEFINITION OF TECHNICAL TERMS Advance of salinity. The movement upstream of saline water, from the ocean or lower portion of a tidal basin, to tlie upper part of a tidal basin into which streams discharge fresh water continuously or intermittently in varying amount. The phenomenon is due to the lack of a sufficient stream inflow to counteract the force exerted by pulsating tidal flows, which mix and diffuse the more saline waters from downstream with the fresher waters upstream, and continu- ously tend to push saline water upstream. Consumptive use. Designates the amount of water actually consumed through evaporation, transpiration by plant growth and other processes. As applied to u.se of water in the Sacramento-San Joaquin Delta, consumptive use is used in its absolute sense, representing total amount of water consumed irrespective of source of supply. Cycle. An interval of time in which a regularly recurring succession of events or phenomenon is completercvious saline invasion, due to the stream flow into a tidal basin becoming sufficient to overcome the force exerted by tidal action and tidal diffusion of salinity resulting therefrom, thus displacing the saline water with fresh water and pushing the saline water downstream. Saline. Salty or having some degree of salinity. Saline invasion. The movonuMit of saline water from the ocean iipstream into tidal estuaries or channels through which frosli water streams flow, resulting in the fresh water becoming saline. An annually recurring phenomenon in the channels of upper San Francisco Bay and the delta of the Sacramento ( 434 ) VARIATION AND CONTROL OF SALINITY 435 and San Joaquin rivers, when the flow of these streams is small during the summer and fall months. (See "Advance of salinity.") Salinity. Degree of saltness or salt content. In general, it is inclusive of all kinds of salt. However, since common salt (NaCl) predominates in ocean water, salinity of water impregnated with ocean water is commonly expressed in terms of its chlorine (CI) content. In this report, salinity or degree of salinity of water is expressed in parts (by weight) of chlorine per 100,000 parts by volume. Salinity, j „ ^ ^ S. See "Advance of salinity" and "Retreat of salinity." Salt water. Water having a high degree of salinity, such as ocean water. The water of the Pacific Ocean has a salinity of 1800 to 1900 parts of chlorine per 100.000 parts of water. Seasonal (season). Of or pertaining to a particular period of time relating to a special activity or occurrence. "Seasonal" stream flow designates the total flow during the period October 1 of one year to October 1 of the succeeding year. "Seasonal" precipitation designates the total precipitation from July 1 of one year to July 1 of the succeeding year. Tlie tenus "a wet season" and "a dry season" designate seasons having respectively greater and smaller amounts of precipitation or run-off than normal, as compared to the average or mean of amounts occuiTing in a series of previous seasons. "Seasonal" consumptive use designates the amount of water consumed by crops or plants during the lieriod of growth, and by evaporation or other agencies during the entire period of substantially continuous use. As related to salinity in the upper San Francisco Bay and Sacramento-San Joaquin Delta channels, "seasonal" or "season" is usei9 m 3 2006 .V(/N 3 2007 RECEIVED JUN 1 7 2UII/ PMeal Sciences Library LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS Book Slip-Series 45H PHYSICAL SCIENCES LIBRARY iinimiimiiiiiiiilililllllllllllllllllllllllll] 3 1175 00481 5448 -) .-, ^-, " -^. / C ^ J. ^ LIBRARY CJNTVF.l? 4 \'rc 111595 PWWBT w ;■«;<• . '.' «f i \tiU,n:tu Vihi ifli ;i;( (liH II :t< Un ■;;' i'rr^T m w it