THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA DAVIS STATE OF CALIFORNIA DEPARTMENT OF PUBLIC WORKS DIVISION OF ENGINEEKING A'ND IRRIGATION BULLETIN No. 4 rc?2^ az no. ■^ WATER RESOURCES OF CALIFORNIA A REPORT TO THE LEGISLATURE OF 1923 CALn'ORNIA STATE PRINTING OFFICE FRANK J. SMITH, Superintendent SACRAMENTO, 1923 TABLE OF CONTENTS. PAGE LETTER OF TRANSMITTAL l 5 LETTER FROM THE CONSULTING BOARD TO THE MEMBERS OF THE LEGISLATURE 7 .\CKNO\ML,BDGMENT 8 FOREWORD • 9 ORGA^^ZATION 11 CHAPTER 889 OF THE STATUTES OF 1921 13 LIST OF TABLES 15 LIST OF PLATES 15 Chapteb I. Recommendatious: to the Legislature of 1923 17 Chapter II. California 19 Chapter III. Climate 24 Chapter IV. The State's Waters' 27 Chapter V. Utilization of the State's Waters 34 Chapter VI. Comprehensive Plan for Achieving the Maximum Service from the Waters of the State 39 Chapter VII. Settlement 52 LETTER OF TRANSMITTAL. January 1, 1923. To tke Members of the Legislature, State of California, Session of 1923. The report on the "Water Resources of California," prepared by the Division of Engineering and Irrigation of this Department, is transmitted herewith. This report compiles the results of the state- wide investigation authorized by Chapter 889 of the Statutes of 1921. In placing this in your hands, I desire to mention the helpful services of the Consulting Board appointed pursuant to the provisions of the act and of the members of the civil engineering profession who have served on advisory committees and reviewed much of the work in pre- paring this report. The}- have freely given to the state valuable advice and assistance that have greatly aided these endeavors. Respectfully submitted. i Director of Public Works, 2 — 25712 LETTER FROM THE CONSULTING BOARD TO THE MEMBERS OF THE LEGISLATURE. To the Honorable Members of the Legislature, State of California, Session of 1923. The Consulting 'Board appointed under the provisions of chapter 889 of the Statutes of 1921, approves the report of the Division of Engineering and Irrigation of the State Department of Public Works, herewith submitted. It is the judgment of the Board that the Division of Engineering and Irrigation should continue this work and that the required appro- priation therefor should be made. Respectful!}' submitted. Chalrniaji c^^t/Mfm^-^^^.^^..^ Members of Consulting Board. ACKNOWLEDGMENT. Much data have been contributed to this report by public and private offices without which the Department would have been wholly unable to produce this volume. The Department desires to publicly express its sincere appreciation to the parties who, through the furnishing of these data, have made it possible to increase the service to the public several- fold, in publishing this report. FOREWORD. The legislature of 1921 appropriated $200,000 for an investigation of California's Avater resources by the State Department of Public Works, Division of Engineering and Irrigation. Accordingly, an engineering investigation has been completed and a report transmitted to the legislature on January 1, 1923. The great mass of data collected and the complex analyses thereof made it advisable to present much of the information in separate volumes. Four of these are in print, entitled : Appendix ''A" "Flow in California Streams." Bulletin No. 5, State Department of Public Works. Appendix "B" "Irrigation Requirements of California Lands." Bulletin . No, 6, State Department of Public Works. Appendix "C" "Utilization of the Water Resources of Cali- fornia." Bulletin No. 7, State Department of Public Works. Appendix "D" "Relation of Settlement to Irrigation Develop- ment." Bulletin No. 8, State Department of Public Works. Chapter 889 of the 1921 Statutes, which authorized this investiga- tion, provided for the appointment by the Governor, of a Consulting Board to advise with the Department in their endeavors. The follow- ing were appointed by Governor Stephens: J. C. FoRKNER, Chairman Peter Cook Jonathan S. Dodge B. A. Etcheverry Harry Haw^good H. A. Kluegel Robert B. Marshall H. D. McGlashan 0. B. Tout U. S. Webb Additional advice on the technical features of Appendix "A" to this report has been sought by the Department from : C. E. Grunsky Louis C. Hill Charles D. Marx H. D. McGlashan 10 WATER RESOURCES OF CALIFORNIA. Also, further advice was sought on the technical features of Appendix ''B" from: A. N. BuRCH B. A. Etcheverry Samuel Fortier A. L. Sonderegger • The Department sought added advice on the technical features of Appendix "C" from: A. J. Cleary G. A. Elliott F. C. Herrmann W. L. Huber A. Kempkey William JMulholland Appendix "D" was prepared by Br. Elwood Mead, Professor of Rural Institutions of the University of "California, and Chief of Divi- sion of Land Settlement of the State Department of Public Works, under cooperative arrangements with the University of California. WATER RESOURCES OP CALIFORNIA. 11 ORGANIZATION. A. B. FLETCHER, Director of Public Works W. F. McCLURE, Chief of Division of Engineering and IrrigaUon The investigation of the water resources of the state and the preparation of the report thereon, was planned, directed and brought to completion by Paul Bailey Fred C. Scobey Chief Assistants Robert L. Jones William S. Post Senior Office Engineers H. A. Armstrong J. J. Jessup Clarence F. Johnson C. B. Meyer S. B. Nevius J. H. Peaslee W. A. Perkins Walter Ruppel S. H. Searancke Edward G. Sheibley Junior Office Engineers P. S. Barker J. G. Bastow L. N. Clinton G. D. Clyde H. L. Davis Herbert E. Doolittle P. K. Duncan - Arthur C. Dunlop 0. B. Field Frank P. Foote George B. Gleason S. S. Gorman William H. Gorman F. B. HiLBY E. R. Hoffman Irvin Ingerson H. E. IviE J. R. Jahn BiSCOE A. KiBBEY Thomas Lewis J. A. Lindsay P. H. Lovering W. J. Manetta T. C. Mead J. W. Merideth S. C. Metcalp R. I. Meyerholz E. H. Moore M. F. Moore W. B. MULLIN T. R. Neiswander T. Neuman C. M. Newton Harry Olsen Noel Pike Norman C. Raab B. A. Reber Glenn Rood E. N. Sawtelle N. E. Spicklemire R. C. Stevenson h. n. sulliger Otto Von Seggern E. G. Waters V. W. WiLLITS Robert L. Wing Charles J. Worden A. A. Wren C. L. Young 12 WATER RESOURCES OP CALIFORNIA. Field Engineers R. L. Allin E. W. Case S. A. Hart Chester Marliave John A. Rice F. W. Bush, Jr. Ed. W. Case CD. Divelbiss Ward Eisan A. Fankhouser F. L. FiREBAUGH Gerald Fitzgerald H. L. McCready G. H. Russell Burton Smith H. S. Williams Geologists Alfred R. Whitman Topographers Redick H. McKee L. 0. Newsome F. Rider Earl D. Stafford J, E. Stafford G. H. Walters A. V. Wilson A. F. McCoNNELL, Editor of Report J. J. Haley, Jr., Office Manager WATER RESOURCES OP CALIFORNIA. 13 CHAPTER 889 OF STATUTES OF 1921. An act to provide for the investigation hy the State of California of the possibili- ties of the storage, control and diversion of water for publie use and public protection in the State of California, and making an appropriation for said purpose. (Approved June 3, 1921.) The people of the State of California do enact as follows : Section 1. It is hereby declared that the people of the State of California have a paramount interest in the use of all the Avaters of the State and the State of California shall determine what waters of the state, surface and underground, can be converted to public use, or controlled for public protection. Sec. 2. The state engineering department is hereby authorized and instructed to make the investigation in this act provided for and for the purposes herein specified. Sec. 3. It shall be the duty of the state engineering department to deternsine the maximum amount of water which can be delivered to the maximum area of land, the maximum control of flood waters, the maximum storage of waters, the effects of deforestation and all possibile and practicable uses for such waters in the State of California. Sec. 4. It shall be the duty of the state engineering department to determine a comprehensive plan for the accomplishment of the maximum conservation, con- trol, storage, distribution and application of all the waters of the state, and to estimate the cost of constructing dams, canals, reservoirs or other works necessary in carrying out this plan, and to report the result of such investigations with recommendations not later than the legislative session of 1923. Sec. 5. In carrying out the provisions of this act the state engineering depart- ment is hereby authorized to examine any and all data, estimates and proposals in furtherance of the above purpose, according to its judgment of their engineer- ing worth, and to cooperate with any department, bureau, office, service, or division of the United States, or of the state or counties, or with any municipality, irri- gation, reclamation, conservation, drainage, flood control, levee, or other district agency for irrigation, reclamation, drainage, or flood control purposes, or for the development of hydro-electric power ; or with any interested association, com- pany or individual ; provided, further, that the eng-ineering department is hereby expressly authorized to accept, receive and use any funds or rooneys contributed to it by any person, irrigation district, reclamation district, water and conservation district or any political subdivision of the State of California for the purpose of cooperating in the work aforesaid and carrying out the pui'poses of this act. Sec. 6. With the approval of the governor, the state engineering department is hereby authorized to employ such assistance as in its judgment it may require and to incur such expense as may be necessary to carry out the purposes of this act. The governor is further authorized to appoint a consulting board, composed of citizens of special and technical qualifications, to serve in an advisory capacity, and without pay, in making the above investigation. Sec. 7. There is hereby appropriated out of any money in the state treasury, not otherwise appropriated, the sum of two hundred thousand dollars, and made immediately available for any of the purposes of this act. Sec. 8. This act shall not in any way be construed so as to deprive persons, corporations, or districts of vested rights. Sec. 9. Any section or portion of a section of any act, statute or law of the State of California in conflict with the provisions of this act is hereby repealed. 3—25712 WATER RESOURCES OF CALIFORNIA, 15 LIST OF TABLES. PAGE 1. Water Resources of California (facing) 32 2. Agricultural Areas and Net Duty of Water in the Sixteen Sections of California 37 LIST OF PLATES. PAGE I. Illustrative Climatology on Agricultural Lands (facing) 24 II. Characteristics of Run-off from California Mountains (facing) 30 III. Map of Agricultural Areas and Duty of Water Sections (facing) 36 IV. Preliminary Comprehensive Plan for Maximum Development of Cali- fornia's Water Resources (facing) 46 WATER RESOURCES OP CALIFORNIA. 17 CHAPTER I. RECOMMENDATIONS TO THE LEGISLATURE OF 1923. One-third of the aggregate value of all of California's products are those raised on the farm, and one-fourth of all its manufactories are concerned in milling, canning or preserving, cleaning, or otherwise preparing food stuffs for the market. In a state whose wealth is taken from the soil in such large portions, agriculture and the problems attendant to its expansion, press for consideration. The accelerated expansion of agricultural production in California has been attained through the more intensive cultivation of its fertile soils. Irrigating about one-third of all the lands farmed, this state now yields an average crop value that is almost three times larger for each acre cultivated, ^^' than the average production on an acre of tilled land in any of the three stat&s that exceed California in total annual production on their farmed lands. The abundant soil-moisture obtained through the sup- plementary supplies, has enabled the responsive soils of California to produce many fold under irrigation and is placing this state in a fore- most position among the states of a nation of farms. Even more than in the past, will the future be concerned in the*^ extension of irrigation to additional areas and the perfection of the supply for those lands now watered, because the agricultural lands of this state are now yielding to capacity under the conditions of dry farming. It is therefore essential that state activities should be guided by thoughts for the orderly and economical development of its water resources, so that all the needs of civilization for water may be supplied while the predominant use for agriculture may expand to the full limit of its wealth-producing powers. In this report, the Department of Public Works and its consultants have endeavored to compile and present information on the water resources of California that will enable your honorable bodj' to guide the state 's destiny with confidence and wisdom. The data amassed, the comparisons, the computations and the deduc- tions involved in preparing this report, are so voluminous that they are printed in four separate volumes. Appendix "A," ''Flow in California Streams," in seventy-six pages of text, two hundred and forty-four pages of tables, and in one hundred and eighty-five maps and diagrams, describes the location, the volume, the source, and the vari- ability of occurrence of the state's waters, and the capacities of storage works required for their utilization. Appendix "B," "Irrigation Requirements of California Lands," in seventy-six pages of text, one hundred and fifteen pages of tables and seven maps and diagrams, gives a digest of all information obtainable on the past use of water for irrigation, and presents an analysis of the future requirements of all "'The California State Department of Agriculture estimates the average value of farm products per acre for the four ranking states in 1922, was, in order of their total production: Texas, $27.50; Iowa, |21 ; Illinois, ?20 ; and California, $59.50. ]8 WATER RESOURCES OF CALIFORNIA. of California's arable lands. Appendix ',' C, ' ' "Utilization of the Water Resources of California," presents a general preliminary plan for obtaining the maximum use from the state's waters and the control of floods. Appendix "D," "Relation of Settlement to Irrigation Development," discusses colonization problems of irrigation projects. All this information, basic for a full conception of the potential value of the state's water resources, its greatest possession, is briefly sum- marized in the chapters of this report. A general preliminarj^ plan for achieving the greatest service from these waters, is presented as requested by the legislative enactment pro- viding for these investigations. This plan outlines a scheme of coor- dinated development whereby a maximum accomplishment may ulti- mately be obtained whose physical works for storing water would cost but slightly more than half as much as similar attainment under an uncoordinated plan. The canals for transporting this water to the regions of use are, many of them, very long and obtain water from several sources, pass through numerous communities, and could be made possible only through organization of large sections of the state. With- out such canals much of the state's waters will go unused. Only then, through united endeavors, almost statewide in extent, can the maximum service be obtained from the state's waters. The reservoirs involved in the maximum development of the state's waters are some 260 in number. These and twice as many more were examined by field parties in these investigations, and a selection made of a third of all the possible sites reported on. Time did not alloAv, neither did the preliminary investigation warrant, a detailed examina- tion of dam sites. Before it is finally known that the selected sites are feasible, borings and exploration trenches must be made. The canals outlined on the map of the comprehensive plan, largely pass through territory of which adequate maps do not exist. Many surveys must be made before it may be ascertained that these canaLs are feasible and that they are in the most economical location. It is therefore recom- mended to your honorahle body that fu7ids he- appropriated to pursue the study of the compu'eliensive plan in greater detail than has been possible for this report. It is also desired to call to your attention the value of records of the waters flowing in California streams. Because of the sporadic way in which the waters pass down the stream channels, reliable estimates of future expectancies can only be made from uninterrupted records of many years' duration. The inventory of the state's waters presented in this report has been based on an estimated fiftj'-year mean flow. This was accomplished \)y expanding records of measured run-off through comparison with precipitation records and, on many streams, the entire estimate of run-off was obtained by comparison. It is urgent that provision be made for the continuance of stream gaging records at least as extensive as in the past, and some increase be made in appro- priations for this work if possible. The construction of all the great hydraulic works on which the future wealth of this state depends, must be designed in accord with these records of stream flow. It is important that they be continuous and on all the streams. Lastly, the desirability of stimulating the rate of rural settlement in California has been pointed out in this report. This subject is placed before you as one worthy of your attention. WATER RESOURCES OF CALIFORNIA. 19 CHAPTER II. CALIFORNIA. Califoruia, second in area, but first among the states of the Union in value of natural resources, lies between the Great Basin of the North American continent and the Pacific Ocean. Confined on the north by Oregon and on the south by Mexico, it constitutes three-fifths of the western boundary of the United States. The six hundred and fifty miles of its meridional length extends to over nine hundred miles of seashore as the coast line pursues a diagonal and more tortuous course in delineating the headlands and coastal indentations of the Pacific littoral. Within the two hundred miles of California's average width, there are 23,000,000 acres of agricultural lands disposed in parcels of various sizes and separated by mountains that occupy much of the intervening space. These agricultural areas are the flat and rolling lands of the state that have soils, disposed in appreciable areas of regular surface conformation, suitable for the production of harvestable crops. The grains, fruits, berries, grapes, vegetables and other farm produce for which California is famed, are grown on these lands. They are located on the valley floors, in the foothills and on the plateaus of the state. Included in the agricultural areas, are lands at present deficient in natural moisture, but more or less conveniently situated for the ultimate acquisition of an accessory water supply. Slightly over one-half of these agricultural areas were farmed in 1920. The non-agricultural regions of California, the mountains, are, for the most part, precipitous, rocky or soilless. Occupying three-fifths the area of the state, these upland regions are spacious collectors of precipitation that fill the stream channels with water, without which much of the state's arable lands could never reveal their powers of production because of deficient soil-moisture. Although they are mostly non-tillable, nevertheless the mountainous regions have supplied the alluvial earth through glacial action, weathering or erosion, that their streams have conveyed to lower levels and deposited there to be- come the fertile, productive soils of the agricultural areas. California's mountains are so disposed that their greater part is comprised within two ranges. These diverge in their southerly course at Mount Shasta within forty miles of the Oregon line, and leave be- tween their bases, the long flat valley that averages a quarter the breadth of the state and half its length. Girdling this valley in their southward course, these two mountain chains proceed in long sweeping curves to a convergence at Tehachapi Pass, three-quarters the way down the state from the north boundary. The encircling line of crests of these two ranges enclose within a rock Avail, two-thirds of California's agricultural lands. This wall is cleft to valley-floor level in but one 20 WATER RESOURCES OF CALIFORNIA. O. M H I— I E-i O O < l-H P O WATER RESOURCES OF CALIFORNIA. 21 place. Through this cutting, the interior drainage issues, flowing westwardly to mingle with the waters of the Pacific Ocean. The mountains to the east of this Great Central Valley, the Sierra Nevada Range, extend for two-thirds the length of the state between Mount Shasta on the north and Tehachapi Pass on the south and their crests are the highest of California's mountains. Serrated and pre- cipitous, their altitudes increase from north to south and culminate in Mount Whitney, 14,500 feet high, the highest peak in the United States excluding Alaska. Between the two extremities of this range, many peaks rise to heights greater than SOOO feet above the sea and eleven peaks pierce the clouds to more than 14,000 feet. In the northerly c|uarter of this range is Lassen, the culminating peak of its vicinity, 10,580 feet high and North America's only active volcano. The westerly of the two mountain chains encircling the Great Central Valley, the Coast Eange, after separating at Mount Shasta from the mass of mountains in the northern part of the state, parallels the margin of the Pacific Ocean and takes a somewhat narrower path in its southerly course, than does the Sierra Nevada Range. The Coast jMoun- tains do not attain the elevations of the Sierra Nevadas, neither are they so diverse of surface or massive in structure. Their highest peaks are less than 9000 feet in elevation and those above 5000 feet are but few in number. Southward from the convergence of these two ranges at Tehachapi Pass and on to the Mexican Border, California's mountains continue as a single chain. Their crests are less continuous and their main axis is less easily discernible than from the Pass nortliAvard. A few dominating peaks rise to heights of more than 10,000 feet, but their general altitude is intermediate in elevation between those of the Coast Range and Sierra Nevada Mountains. This mountain range divides two very diverse regions. To the west, the Pacific slope, the agricultural lands of which extend from the ocean's margin well up to the mountain flanks, is an intensively developed and highly productive area of moderate climate fluctuation; while to the east lies an undeveloped expanse, almost rainless, with climatic extremes, and largely unproductive through lack of an accessory water supply. However, there are extensive productive areas in Imperial, Palo Verde and Coachella valley's which have acquired irrigation sup- plies and are realizing on the great fertility of their arid soils. In this expanse of flat lands and mountains is Salton Sink, an inland sea, the surface of which is more than 250 feet below ocean level. On the Pacific slope of this dividing range in the southern quarter of the state, in its broad valleys and adjacent to the seashore, is spread • the bulk of California's agricultural lands that lie west of the state's mountains, in all, one-sixth of their total area. These lands are located mostly along the streams near their ocean outlets. Northward from Santa Barbara Channel they are scattered rather meagerly along the Pacific margin, for their continuity is interrupted by extensive stretches of precipitous shore line that rises abruptly from the water's edge. To the east of Southern California's dividing range south of the Tehachapi Pass, one-tenth of the state's arable lands lie between their crests and the state's eastern border. Northerly from these lands and along the eastern border of the state, another tenth of the agricultural 4 — :i5712 22 WATER RESOURCES OP CALIFORNIA. WATER RESOURCES OF CALIFORNIA. 23 lands are located in scattered parcels in the elevated valleys and pla- teaus east of the crests of California's mountains. These are mostly situated at elevations of from 4000 to 5000 feet or more above sea level. The extreme range in altitude of California's variegated surface is from two hundred and seventy-five feet below sea level in Death Val- ley, to fourteen thousand five hundred feet above, attaining this eleva- tion at Mount Whitney, but seventy-five miles distant from the lowest depression. The greater part of the fiat lands, or about one-fifth of the total area of the state, lies between the elevation of the ocean's edge and five hundred feet above. These flat lands comprise the gently sloping ocean littoral, an extensive mountain-girdled valley known as the Sacramento-San Joaquin, and the almost rainless area in the south- eastern corner of the state. These regions, 33,000 square miles in extent, include the bulk of California's agricultural area. Higher in elevation than these flat lands, are the slopes lying between the plain-like areas and the base of the mountains. These are the rolling foothills and the more elevated valleys, lands that are transi- tional between the plains and the highland regions. Located between 500 and 2500 feet above sea level, they comprise about one-third the area of the state. One-quarter of all the agricultural land lies in this transitional region, and only the scattered parcels in high moun- tain valleys and that on the plateau in northeastern California, lie above it. Higher than 2500 feet in elevation lie the mountains proper. For a large part they are a rugged and precipitous region of steep accliv- ities, of rocky extrusions and serrated ridges, and of deep canyons and rock-walled gorges, that comprise nearly half the area of the state, but interspersed at intervals throughout this highland region are mountain valleys and meadows, attractive in their richness and scenic beauty. The mountain and foothill regions, together, are over triple the area of the agricultural lands. In receiving greater precipitation, the mountain regions shed large volumes of water into the streams and rivers and are the source of nearly all of the state's waters. 24 WATER RESOURCES OF CALIFORNIA. CHAPTER III. CLIMATE. The California year is distinctive from that in most other states of the Union, in having but two well-defined seasons, summer and winter. This occurs because the transitional periods, spring and autumn, are brief and devoid of special features other than that they are inter- mediate between the more clearly defined seasons of summer and win- ter. The summer, or growing period, is long, warm and without heavy rains; the winter is the dormant period, or interval of retarded growth in the annual cycle of plant life, and normally is short, cool, and at times stormy. The greater portion of the waters precipitated upon the lands of California fall during this season of winter. The covert of encircling mountains and the proximity of an ocean that borders the state with nine hundred miles of coast line, so modifies California's climate that only moderate seasonal fluctuations of tem- perature occur over most of its area. Any great extremes of heat and cold that do transpire are confined principally to the high mountain or arid areas. On the low lands generally, the mean monthly temper- atures show departures from the average for the entire year, markedly less than similarly compared heat measurements for the adjoining states or those located eastward and included in the same latitude. California is exempt from hurricanes and tornadoes, and though the mountainous regions experience days of intense cold, blizzards are unknown over the valley areas. Favored of nature through immunity from devastating tempest, rigorous cold, and enervating heat, California's climate is heralded the world over. The outstanding features of the state's climatic regime are the rains of winter and the sunshine of summer. During the winter months, the state is swept by moisture-laden winds that traverse large areas in their journey from one locality to another ; while in the summer or dry season, similar winds may blow, but they are rainless and serve only to modify the mounting temperatures that ensue from continuous sun- shine. This distinct division of the year into a short season of inter- mittent drenching rains and a longer season of warmth and sunshine, determines that, more and more, in the years to come, this peculiarity of climate will influence the activities of man in this state. As greater numbers of people elect to live within its borders, water will be needed in increasing amounts for every activity, and all of California's waters originate in the precipitation concentrated in a few months of the year. Of greatest economic importance therefore, among the climatic phe- nomena, are the moisture-carrying winds that visit the state at annually recurrent intervals. In blowing over the land areas, these winds pre- cipitate varying amounts of water along the way as they are cooled, and deflected or diverted by local topography. The shelter of knolls, of hills or mountains, or of ridges or spurs, may lessen the amounts reaching leeward areas, while increased quantities may fall on more Plate I Plate I 25712 Facing p, 24. WATER RESOURCES OF CALIFORNIA, 25 exposed locations. The greater cooling of the air upon moving up slopes and arriving at higher elevations, usually inceases the precipita- tion in the mountainous regions over that on lower lands. The annual quantity of moisture released from the atmosphere to fall upon the several parts of the state, is as variant as the rugged topog- raphy. ^^^ In general, precipitation increases in depth from south to north, being least in the southeastern corner of California where it is nearly zero, and greatest in the North Pacific region contiguous to the Oregon line where the mean annual rainfall attains a depth of one hundred inches or more. The mountains generally receive more than the valleys between them. The greater portion of the flat lands have a mean depth of precipitation of less than twenty inches annually and one-third of their area has less than ten inches. Depths of more than twenty inches are mostly confined to the mountainous regions which on their more elevated portions receive from thirty-five to one hundred inches, or more. In the highest mountain regions, precipitation occurs largely as snow ; on those of lesser altitude both snow and rain fall, but the mantle of snow on the earth is of short duration; while the areas lying closer to the ocean's level, seldom experience a fall of snow but receive all precipitation as rain. The mild climate of this lower portion of the state extends, therefore, to nearly all its flat-lands, to the gently sloping ocean littoral, to the extensive mountain-girdled valley con- taining three-fifths of all the agricultural lands, and to the rolling foothills and detrital-filled valleys transitional to the highland regions — - in all about one-half the area of the state. To depict the features of rain, temperature and frost in California's agricultural areas, Plate I has been prepared, "Illustrative Climatology on Agricultural Lands." For convenience, the tillable lands of the state have been segregated into sixteen divisions or sections, the bound- aries of which are shown on Plate III, "Map of Agricultural Areas and Duty of Water Sections." A station of the United States Weather Bureau has been selected in each one of these sections to illustrate its climatic features, and the mean precipitation and temperature for each month of the year, together with the frost-free periods for each one of these stations is graphically delineated on Plate I. The top section of this plate shows, by means of colored columns drawn upwardly from a common base line, the mean monthly precipita- tion that has occurred at the Weather Bureau Station that is named at the foot of the bar. At the extremity of each equally-spaced cross-line on the sheet, at the left margin, are numerals which express values of mean monthly precipitation in inches of depth. The colored columns in intercepting these cross-drawn lines, indicate by their height, the amount of mean monthly precipitation. On the middle sectioja of the Plate I, the mean temperatures that have prevailed during each month of the year at the stations named above them, are represented by similarly colored columns that also project upward from a common base line. These show the values of mean monthly temperatures by their intercepts on cross-drawn lines that are numbered with temperature values at the left margin. "'See Isohyetose Map of California contained in Api>endix "B" to this report, for complete delineation of precipitation over tlie state. WATER RESOURCES OP CALIFORNIA. 25 exposed locations. The greater cooling of the air upon moving up slopes and arriving at higher elevations, usually inceases the precipita- tion in the mountainous regions over that on lower lands. The annual quantity of moisture released from the atmosphere to fall upon the several parts of the state, is as variant as the rugged topog- raphy. ^^^ In general, precipitation increases in depth from south to north, being least in the southeastern corner of California where it is nearly zero, and greatest in the North Pacific region contiguous to the Oregon line where the mean annual rainfall attains a depth of one hundred inches or more. The mountains generally receive more than the valleys between them. The greater portion of the flat lands have a mean depth of precipitation of less than twenty inches annually and one-third of their area has less than ten inches. Depths of more than twenty inches are mostly confined to the mountainous regions which on their more elevated portions receive from thirty-five to one hundred inches, or more. In the highest mountain regions, precipitation occurs largely as snow ; on those of lesser altitude both snow and rain fall, but the mantle of snow on the earth is of short duration; while the areas lying closer to the ocean's level, seldom experience a fall of snow but receive all precipitation as rain. The mild climate of this lower portion of the state extends, therefore, to nearly all its flat-lands, to the gently sloping ocean littoral, to the extensive mountain-girdled valley con- taining three-fifths of all the agricultural lands, and to the rolling foothills and detrital-filled valleys transitional to the highland regions — in all about one-half the area of the state. To depict the features of rain, temperature and frost in California's agricultural areas, Plate I has been prepared, ' ' Illustrative Climatology on Agricultural Lands." For convenience, the tillable lands of the state have been segregated into sixteen divisions or sections, the bound- aries of which are shown on Plate III, ' ' Map of Agricultural Areas and Duty of Water Sections." A station of the United States Weather Bureau has been selected in each one of these sections to illustrate its climatic features, and the mean precipitation and temperature for each month of the year, together with the frost-free periods for each one of these stations is graphically delineated on Plate I. The top section of this plate shows, by means of colored columns drawn upwardly from a common base line, the mean monthly precipita- tion that has occurred at the Weather Bureau Station that is named at the foot of the bar. At the extremity of each equally-spaced cross-line on the sheet, at the left margin, are numerals which express values of mean monthly precipitation in inches of depth. The colored columns in intercepting these cross-drawn lines, indicate by their height, the amount of mean monthly precipitation. On the middle sectioja of the Plate I, the mean temperatures that have prevailed during each month of the year at the stations named above them, are represented by similarly colored columns that also project upward from a common base line. These show the values of mean monthly temperatures by their intercepts on cross-drawn lines that are numbered with temperature values at the left margin. "'See Isohyetose Map of California contained In Appendix "B" to this report, for complete delineation of precipitation over the state. 26 WATER RESOURCES OF CALIFORNIA. The lower section of the plate, designated "Frost Free Period," has transverse bars which progress partially across the paper. In so doing, their length exemplifies time. The space between the left and right hand margins represents the full twelve months of the year. Vertical lines divide this space into equal units of time and the monthly intervals are accentuated by heavier drawn lines. Spreading across the sheet and crossing these vertical lines, the sections of the bars in solid color show the duration of the period at each of the sixteen Weather Bureau stations, within which frost has never occurred. Extensions of the bars, hatched with colored shading lines, show by the distance between their extreme ends, the average duration of the frost-free period for the years of record. The bars are similarly colored to the columns of temperature and precipitation and are named at the left margin opposite their ends. Plate I illustrates in a pictorial way, the climatic characteristics that prevail over California's agricultural lands. The precipitation section of this graph shows that almost without exception, the rainfall in amounts to be of much value to agriculture, is confined to the months of November, December, January, February and March; while the temperature section shows that the period favorable to the growth of plants and vegetation, is from March to November, inclusive. Except for March and November, the rains in California occur during the time of the year in which most plants are dormant and for seven warm months of the long growing season, the rains on the agricultural lands are light. Thus for a period during each twelve months, California is favored with precipitation-releasing winds, and once a year at coincid- ing times, the mountain ranges are clothed in snow, foothill eminences and slopes are drenched with rain, and valleys and plains are wetted by the same spacious storms; while through the remainder of the annual cycle, sunshine and warmth are dominant and precipitation is small in amount. WATER RESOURCES OP CALIFORNIA. 27 CHAPTER IV. THE STATE'S WATERS. The moisture-bearing winds that traverse California during the winter season precipitate three hundred billion tons of water annually upon the surface of the state. Most of this falls as rain or snow upon the mountain areas. This precipitation: as rain, strikes the surface of their slopes, oft* which portions run toward lower elevations; as snow, it mantles the earth's surface or collects in wind-blown drifts to await warmer temperature for conversion to liquid water, that may likewise pursue a downhill course toward the ocean. These moving waters, ever .journeying to lower elevations, concen- trate in the ravines and gullies toward which the surfaces slope. They follow the steepest gradients and the most deeply cut depressions and, continually enhanced in volume by like accumulations, restlessly pursue their downward course until finallj^ they become engulfed in the earth's vast raservoir of waters — the ocean. Falling on the drainage areas as precipitation, concentrating on the land surface as run-off, coursing down the water-channels as stream flow, these waters reach the ocean as drainage; and so by returning to the storehouse of waters from which they were first vaporized and carried to the mountainous area by the moisture-bearing winds, they complete a circuit of travel. The same storms that drench the uplands or clothe them in snow, precipitate lesser amounts on the lower flat lands, and this almost entirely as rain. Lacking the surface inclination to put the water in motion, the earth coverings of these lowland areas largely absorb the rains falling upon them or, detained in pools or puddles or in the saturated top soil, they are later evaporated back to the atmosphere. Only during extremelj^ heavy downpours of infrequent occurrence do the flat lands contribute run-off to the stream channels. California's Avater-produeing area is the mountains. Influenced by the topography, elevation, and exposure of the divers localities, the storms traversing the state deposit varying quantities of water on their diverse surfaces. In each area, however, only a portion of the waters cast from the clouds ever reach the stream channels ; the rest is dissi- pated through evaporation. This division of the waters starts imme- diately with their precipitation from the rain clouds and continues throughout the entire water movement. Moisture is evaporated from the falling particles of rain or snow, from the gathering waters on their catchment areas, from the snow fields, from wetted soil areas, and from the flowing streams. Water is also vaporized from the vege- tation that grows on the mountain slopes. Much of the moisture that Avets the earth's surface is absorbed by the root systems of vegetation, so that where trees, bushes and undergrowth are dense, large volumes of water are vaporized through transpiration from plant-surfaces. So evaporation is persistently in progress, and, effectively and without respite, reduces the volumes of water precipitated upon the earth's sur- 28 WATER RESOURCES OF CALIFORNIA. A STREAM IN THE SIERRA NEVADA MOUNTAINS. WATER RESOURCES OF CALIFORNIA. 29 face. The fraction of these waters finally becoming stream flow in each season may be less than one-fourth or more than three-fourths of the total precipitation, according to the amounts falling, the contingencies of the season's weather, and the circumstances of topography and geology on the catchment areas. Except as it falls upon frozen or nonabsorbent surfaces, precipita- tion upon striking the earth must first moisten its top-covering, and it is only after thi^ has become saturated that waters gather on the sur- face to journey down the slopes of the catchment areas. While col- lecting in puddles and pools or moving down the slopes in streamlets, some of this run-off trickles into seams and cracks of the mountain's rocky structure, while other ciuantities are absorbed by pervious soil- coverings. This moisture advances by the attractions of gravity and capillarity and. filling the pores and interstices of the earth's crust, penetrates to great depths. Although usually only a small portion of the total, these percolating waters are especially valuable to man in their reappearance at lower elevations as perennial springs to moisten meadow lands or to increase the waning summer flow of brooks and streams. These tardy waters, in penetrating the subsurface regions and pursuing a dilatory underground course, wet the beds of the stream channels the year round and furnish nearly all of the dry season stream flow, and are the principal waters available Avhen the great volume of winter run-off has subsided. Their total amount, however, is small, for three-fourths of the run-off from California's mountains concentrates in the stream channels, hurries down the water courses and passes by the low-lying agricultural lauds \^"ithin forty-five days after its precipitation upon the earth's surface. Follo^wing precipitation so closely, the state's waters appear in the stream channels in fluctuating flows having a striking similarity to the periodic occurrence of precipitation. Plate II. "Characteristics of Run-off from California ^lountains, " presents the hydrographs of five streams, each typical of a separate section of the state. These hydro- graphs show the run-off, month by month, for the greatest year and for the least, as well as the mean monthly flow of all the years of record. For convenience of comparison, the monthly run-off is plotted in per cent of the annual mean. These hydroeraphs show how the bulk of California's waters run off their mountain catchment areas during the winter months, and how only meager quantities flow in the streams during the middle and late sunmier. The great variation between the rim-off of the maximum and minimum years shows the wide limits between which seasonal run-oft" fluctuates, and how, in the smallest season, the usual scanty summer flow is much reduced and this much earlier in the season than in other years. This investigation has studied the features of flow in all the streams of the state, ^^' the amounts of their waters, and their variability of production. All discoverable data have been assembled and analyzed and, although actual measurements of flow are available but for a limited number of years on the major streams, through comparison of these data, quantities have been ascertained for eveiy stream. For these purposes the minor streams were arranged in groups and these groups, together with the major streams, total one hundred and forty in number. The location of each one of these streams or groups of '•'See Appendix "A," "Flow in California Streams." 30 WATER RESOURCES OP CALIFORNIA. minor streams is shown on the map of California, Plate IV, "Prelimi- nary Comprehensive Plan for Maximum Development of California's Water Resources." Each basin bears a number on this map which refers to a table at the top of the sheet. This table gives the name of the stream draining the basin or the main stream in the group of small basins. An audit of all these waters is presented in Table I, "Water Resources of California," in which is a complete inventory of the state's waters. In listing the flow at the head of the main body of agricultural land on each stream, the waters in this table are practically all that are available, both surface and underground, for use on the flat lands of the state for the subterranean waters of the flat lands largely receive their supply by percolation from the stream channels crossing them or from percolation of diverted waters poured out upon their land surfaces. The first two columns of Table I contain the names of the streams or groups of minor streams and their reference numbers. Through these reference numbers, information that is too voluminous to incorpo- rate in this summary tabulation may be conveniently traced in the diagrams and tablas of Appendix "A" to this report. Spread out in forty columns to the right of these first two panels are values which characterize the amounts of water in each stream and its variability of flow. Of these columns, the third contains the areas of the drainage basins, while in the fourth to the twelfth are values of their run-oft' expressed in a variety of units. Included among these entries are the quantities of wator running off their collecting areas in an average season, and in the seasons of greatest and least run-off. These quantities affixed to each stream definitely locate all the state's waters. The mean seasonal quantities express the average amounts in which they may be expected to appear and constitute a statement of practically all existing waters, while the values for the extreme seasons show the limits between which the flow of successive seasons may varj^ While the average annual water production of all these streams is 72,500,000 acre-feet, this invoice of California's waters shows that the combined maximum yield is two and three-quarters times this amount. and that the combination of all streams for the least seasons is but three- eighths as much as the average annual amount. The total run-off in successive seasons, then, fluctuates between limits, one seven times the other, and the value of any one season lies at random between them. In addition to changing from year to year, all the streams of the state have a fluctuating daily flow. Inclusions have been made in columns 13 to 18, and 35 to 42, of Table I, to define the extremes between which the daily flows are accustomed to range. Columns 13 to 18 give values to the run-off during the months of July and August. These two midsummer months are times of the year of nearly the least flow, and in which water is of much value agriculturally. The quan- tities include the entire month's run-off expressed in acre-feet, and when divided by sixty afford approximate values of the average daily flow during the low water periods in cubic feet per second. Con- trasting them, are the values of flood flows in columns 35 to 42. These entries are of special import in not only indicating the upper limits of variability in stream flow, but also in indicating the maximum Plate II 110 100- 90- 80- 70 30- o 5 20 SACRAMENTO RIVER 1904 VEAP OF MAXIMUM RUNOFF MEAN RUNOFF lllhi.,-,ii 1898 YEAR OF MINIMUM RUNOFF u. 2 < 2 < to O Z Q State Department of Public Works DIVISION OF ENGINEERING AND IRRIGATION California Water Resources Investigation chapter 889.. I9il STATUTES 25712 Facing p. 30. 110- 100- 90- 80- 70- 60- u. u. O _l < < < 30- Li. z S 10- z Li. t n PUTAH CREEK 1909 VEAR OF MAXIMUM RUNOFF L- 1 z a i30- Z s 20- lOJ 0^ k MEAN RUNOFF 20- 10- 1912 YEAR OF MINIMUM RUNOFF aiaj™Q™33 30U0 aj D50- S40- o J 30 o 2 20- 10- 0- 20- 10- TUOLUMNE RIVER 1907 YEAR OF MAXIMUM RUNOFF MEAN RUNOFF 1898 YEAROF MINIMUM RUNOFF 5 < 5 < U) O Z Q 110- 100- 90- SANTA YNEZ RIVER 80- 1914 YEAROF MAXIMUM RUNOFF 70- .60- u. O - z ^50- < ho- hi 5 30- s 1 u. K20- 1 u - Sio- li z li. |o-l 2: - BBBw»— — - ^30- 1- Z ^20- H 1 MEAN RUNOFF 1 1 , 20- 1912 YEAROF MINIMUM RUNOFF 10- -ll.- "ii;2<2^^ul»ni« . _.t Kim Tnbulva •Aumo Creit Gtngp *Ml Diablo Cratk Urc~.p Baa baadta Onct ■Claraittnl Cn*k Group Su> UwiuoCrvek JUuDoU Cmk .onCwkCr™,, CoTCU Rira Cvadilot* rtjitt *L» Giba Crok GcMp Jan FiomiidUi Crvk *3aij MiUo Cndi Uioup. Saioiiil run-dS Iram <]niii>(E ma abort lb ill body of atmultunJ bnda. pH I31.8U) ss.a» u.:ao 019.1(10 e.v»,ooa i.isi.MU sta,(w t3I.S(» 1 10.80) 27.100 U.SOO Z4«l iBS.l«l rajwo 1S.O0O tJJW iE.tao 19.100 s.zoo 80,100 0.000 BSJOI i.f0M00 S.I10.7D0 mtoo 121.100 1JM.40CI 1M0.MO s,zja.oua J,170.«» IW-tOO I.M1,J«I 8,182 t.iM ;s 113,800 I.DU.TOa iKi.m J.1S0 2,rw 3;tos 3,809 ssu.8da 1.807,100 22.700.000 3.810,000 83»W0 3JW 2.ST7 13.090,000 812.000 *.170aW 117 JOO 1,117.000 3,U) ill 4,287 209,000 1.818,000 1J3B,000 iS.100 iljoo 4ii.iMa lO.UQ 2U.81U 14,100 J7,!»00 2!t,70O aajmu 1,I81,UOO »n.ooo 1.412.000 118,100 I2.>W ui,aiw H7Da 21V,I00 Mpg.900 1,2X1,100 Z,IH.iOO 4,700 1,1»I,«>0 4V.UM T.SO0 3H.O00 470,000 4,100 KO.OOO £81.000 82)00 too 2V.400 179.000 U ice.0D0 iSf. 10,200 }gT.ioo 40>n 8,800 fi2.10U zso S,t70 84.700 17,000 17,900 u,toa Ki.lXO &g7,9oa 2tl) 3,370 ,SL^ Hun-olI durinc Auiuit. J37.800 USOO 6.000 771,800 ll>00 2I,SD0 100 2,475 I29,7C« 19,100 8,000 24,600 370 1.070 3;7B0 01,800 s'ooo 11,400 tAW urn 42,toa 2iM,Doa WiU'r-yidd for irrigitlan sliird Bow Id itrcama. MiumuiD Dit yiM pc«ibli>. l,37S,KO H.US.UOO 1.3U.»0 7»,aso 34S.S80 1tf.710 2.175.130 37.770 328,830 7.350 fi,4Hl H,490 1,015,830 1,470 49,880 3.430 4S,740 48,180 12,380 12.100 18,500 15,760 3,4«) 63.670 2,798,770 201,3(10 427,300 3.7IS.750 7.358.080 2.7M.0OO 115,500 9,630,8911 10,587.000 493,500 8,039,940 194.250 t.ll3,7M 38,860 s,uui.oin 319.000 8II.I00 1.470.760 I30.S0n 1,172.000 1.383.400 33.1,000 1.74B,(MD 141,900 4,113800 lOtitOO 30.800 121.860 31.630 30,730 43.9O0 833.900 1,317,150 233,000 1,103,800 3M.7W lt2,4W 606,tWO 310,000 200,400 70,000 11,960 383,300 70.400 NeljicWor4Dp.rc. SlonlF capBFily miuiml 117,940 165,320 3,071.600 <62:»da 143.100 X860:S10 370,370 143,350 3,113,400 70,760 1.001,040 1,840.230 105,680 1,007,090 Z2,S«U K»:350 13,&I0 l,m,780 20,300 322,000 32,!iSO 1,113,670 M,010 108,500 321,900 38,880 23i40a 168,730 46.100 ITS,S00 368,970 41,320 10,810 5,000 3,900 38,210 18,000 37,020 8,^0 32,010 8,800 37,400 549.030 882.070 334.150 73.900 301,850 37,320 2.O80 37.080 33,520 3,800 40,630 3,330 5,120 IhOOO 1 8.300 0,760 29,iS0 453. 00 823. 20 a, 40 630, 00 . 3, 90 430,730 473,800 0,740 "S 8,720 136,600 13,870 300,640 IJ 24,050 1J8I,18D 45,530 H0.70U 176,030 4,064.500 578.700 179.300 2,641,780 99,700 U3e,3ao 34,aS0 300,360 277,500 48,100 391,000 310,900 53,400 13,650 8.250 »,S80 47,300 17 ,740 44,720 23,500 1 ,870 303,540 23,500 380,200 33,850 1B9.000 342.180 60,070 34.150 3,800 33.850 449,050 48,600 »1,000 17,800 57,600 39.350 34,000 2.800 40.050 11.000 34JS0 787,740 1,303.430 493,270 143,070 253,080 45.680 in.MO I.4S8.030 34,390 305.350 54,7,«l 170.400 499,500 12,040 14,720 3,780 73.790 30,970 126,720 4g.K3a 24.870 33,310 30,880 189.080 NdlyicMofBOrerwDlof Kuoaiu mo-oR, 176,940 547,980 6,967,400 694.440 318,010 3,170,100 30,460 1,009,140 43,800 56,320 351,600 363,030 5.3ID 335.600 4.800 77.550 101,930 425,380 471,8(0 1,598,330 G,I66,9S0 868,050 329,730 74,470 I8.6«0 37,890 633,000 583,770 151,920 693.900 38,330 35.010 61.500 1,043.720 1941530 145.6(0 741,230 TTOwM Kton^ capacity requind 1,943,310 i,ii3,»(a 54,170 U0,3I0 6.950,300 310,160 350,830 3.698.4U 139,580 1. 856 ,8a) 34.790 238,750 531,230 - 14,480 1,430.830 47^310 5,334,310 3,13T.4«0 1B9.3»I 141,000 370,430 809,250 5,070,360 403,770 2,917.860 78,530 635,150 1,084,560 u.iio oldmnacT Hom fur 24 boui in maioiludf er tlian Ubulalol v ElpWlod OCC UTfTBC* o( ODM I Tit 24 boun Diua) 100.500 31.KW 9,300 fvrtlDU HUAfVIEUll oldmufi 50,400 48LI0O 50.400 13.000 64,100 180.000 146,500 0,010 11.T00 110.000 "19.600 11.100 4.170 1).4IH '"suoo 5,«60 2,640 3,H0 8iwt for 34 boun equal in ciuf ailudt or cmlct tbu IkbuUlcd niat. 17M0 43,200 5.070 11.300 305.000 i63,6o6 11,000 'iiao' I4.ID0 19,900 12.010 10,660 la 160 -nan of timt" flovi F» 24 boun ciual in macmtaile or paUr than labuUtal TtTuc. 125.400 45.000 10,300 160,000 9.no 33.800 1.450 43.100 1.460 13,100 io',3io IIJOO 19.400 SACRAMENTO BASIN, pjmjlecitt Rim (Uppn) abon Pll Ritw. •flMkbooe Cratk Gt™p ChwOnek Canmaood Owk , laHnnKDla Rinr t| Bid Glue 'ntdBukCndtareop,'. SuBfOmk. OiikQHk PtHakOwk . SAN JOAQUIN aASIN. "Ornliata Creek Oroop •YokDli]Cciid.Gto»B Kambllirw . "^ 'UadiibCrwkCicoijD,., . KwRlnr DtrOutk SMjOMuinlljmllJppir) ,. CoUaaaood Oeck rrWDO Riiv •Oaulton Cmk Group Ctomhilb RiTCT 'Dulrliniin OwtGnjup ., •Qxrn r„.,l,' U«u rrrr k ■Ourn* Ctt»k Group MtMmt Rit»r . ,. rgolumng Hinr . . . 'Wildcit Cmk Croup StaniilBW Itiw UUtjohB Cr«t •MirWliOraikClOTp.... ., ,, CiU.c™.Rim MnkEluBuic (titer . , *% I Id Oak Group OvuDms HiTtr Tot4li and emm Tdc SU Jctq^ B^ S»N FRANCISCO BAY BASINS. ■Ml tjiaUnCrftckOroup aw l-tiio ftt-k naa Lnndio Crt«k ... *ChniDonl Crack Group. ak» Loreua Cnek Alamnla Cmk •MiarioB Crwk Group PouleiciA Ct«ek UvDlaRJRf 0»il»Jup» lUnr, *Lw Galia Owk Group , , 9aa »ueaaiuU 0«k "Sui ^t^tfo Crwk Group TuUU *flj imia tor Su Ffucwo Bay NORTH PACinC BASINS. Sniilh Kiirr Kkmilti Hiirr »bttti lUtci Scull R,ni Stbooa Kint _ _'»bIo Ciwt Su IfBodni Crrrt Sid Li»i(uoCn:«i AIudbIi CikI; iiiBC™lGfuuj Sui FriKi»]iuIo Cwk NOFTTH PACIFIC BASINS, - Ri.tr •Giolili Hirer Gtouv *Siaj™ Cr«t CJroup •BoTmu Ciwi Orwijr « KorU f^&c &*Bat auU Vcibil Cmt a»n LuB Rtj Itiiw " ta Ma/^nts River It iiciula itivtt Tnhulvia ita AiB Rim Tribuuria 1 Cabntl RiTw Tntrulvia . ■La Ar«Els Itinr TnbuUrici . . ■KUibu Ri™ OroMp ■&sl> Clan River tribuLuis . . •Jika Oiwii Urwp. . &DU Ym Rintr . *Sbn Lud Obtf^ Crrrl Grcnip ■StlitiM Rov Tribvtana . ... •fuwo niv« Tribuluia ■Snqud Owk Group 'I^aadcniCniikGroap. ToUbudn u(iirSDalbi>H)SaSMiH GREAT BUI Tulc Itlu Ctnuy ■Go* IaIu Uruup . . •Coabcttd Ukr> Buln •Surpmt Villry Orogp . . ■Middint FbiuOrvup -Sciwh! Cmli Group . ■E^fle UU Gruip 'HoACT L*if Gf^Tup 'Uk( Tibw Bsu TiMckH Rivet MdolK Modon Group wGralBuiB . MurorSuU . »^6 ».«oo UODD S.OTJ K).i0(l 139.400 3.U0 700 10,600 99,WI I2J2O0 2,900 9,500 7.700 1,700 2.90U 3.300 41200 271,100 32,200 &,40U M,MW 392,700 i».3oa HMO' 1.117,00 1.119.100 I.U9,IOO 276.000 H8.no 1.070,000 510.600 711 OCO 231.300 407,7i.s3a asisoo 113.600 18.160 317.600 IBJOO (3.200 0,010 K),9iO :8.120 a:ffi 73.150 tl.160 69,080 384.790 111,920 31,570 1,1)9, teo sa,800 va.48a ao,i2o »,ooo i7,480 18,810 &7,4iO 34.000 8,600 9,450 12,300 13,800 3,900 40,050 11,000 118,700 591,250 3,020,000 105,800 124,850 708,300 139,10) 130,050 01.060 169.080 35,760 803,580 579.130 3,603.200 231.060 526.910 1.728,250 SS.870 76.310 20.950 334,050 1.635,230 395,900 268,700 iiaa 41,450 58,300 im 06,110 116,130 18,800 4S.500 195,400 180.500 1U.O0O 430,040 313,100 359:260 87,600 (ilioo 50.000 66.150 07.830 16,600 173,k Aluncdi Cnil 'MiODDii Onli r,t..i,i, PauUacin Cnuicaoo Bi NORTH PACinC BASINS. Riiw. KkEOalh itirtr Silmoa Rjnr TKnilr Kiiu Hed«oodCTOk Mid Kiw. Edltinr .. ■" Cretk. 10.470 15,730 16,370 UoiptUiCmlE ISiliiiotiCmkr.rciip,.. "BoUnM Onk Graup, . . TolakudtM ■ rocMorthricifieBi SOUTH PACinC BASINS. SMKp|[oIti.ef.... SMtik YmIh] Cmk Eu Luii Ki^y Riw &a)aMinonUHin»:'" *StDJu> Riiw TribaU nuo lB,i66 ^l> \Ba Hirer Tnlutvia "Su Gibrict Oinr TnbuUnM Iff ,?'«''" f*"™ Ttibgl»r«l •.*Wibul{)»erOroop ... 'SuuClMRim'njbiittriM Voaliui Hirer •Jilinn Cnik Qroup SmU Ynci Riis. . , , . , SuAnlonioCwdi tMU Muia Rinr. *Sm tub (itun Crttk Croap . . . *Sdiiai Rira tVibuUiu* •Puijo Hirer TWbiiUrita . •Siiutl Owk Group •P«aJua CWk Gronp ToUb tnJ nuooi loc Soutb PfHt Bi GREAT BASIN. •Tile UXe Group ■GwvUke Group 'B»Dif Uka Group. .... *Uka1Ua(B«M Tr*ckMitint... Wat Fork OtnooRiow.. Rati Fork CknaaRJiir,.. WalVFtlkuRlra Eut Wiiker llinr. . . .. ■Urao Uka Grovp .... ■AioU Madova Group. . . *OnaRiirs(Droa) ... 'Ubop Onk Omop •OnM lAk> Qn«]> MojinItil« ■Alldops Villoy Group . . . Wlitcnltf RiTW. . •OTaEAMS GBOUPED IN ONE ENTRY IM TABLE. re mileikddilionL EMT*bla49, 17. Cbvra Cnck. Stillnltr Cnck. 30. Ajb Cntk Bar Crak. U. BackboDt Cr«k, Rmk Cntk. Olur Cnck. 17 MiQ Cnck. D«r Cittk. Anltlopc Cnik. Bit CUro Cr«k. Litllt CtiHo Cieck. S)-aaon HoSow, Sbnp HoUn, Griub BoDo*. Mud Cmk. Hock Cnck, Pioe Crack, Ziaimnbed Crack Cwntl Ctetk, RilUoukt Croak. 9li«ct Oaak. Bniah Creek. Rio do U* BrmaioL 4a Bulla Cnck. Utllo Dnr Cmk. Char Crnk. Gold Rua Crnk. Cbimlrn Rjiine, C«l Ouyon. 60, North Hoocut Crttk. South Hoocul Crak ffjTDUO Cnek, WysnduUr Cmk, Dry Creek. 51. CoDD Cmk Antdoic Crnk. Auburn R*%-iat. M, RanliCr(*k,Niinb Fork Red BiDk Cnck. Sstrtli Fork Red Bank Creit 57, Elder CVerk. Tbotna* Crock. Ria Cmk. 50. BwEbrizht Cmk WUIo* CnA. Ldcu Crak Buelcn Cmk, Funti Crnk. Stout Corral Crack. &i>d Crirk. Frtabnlo Cndc Salt Cnck. epnnt Cratk. C«nin. Cratk. 61. LiUlaPuiiiclic Cnck. iMQiaSaB.'lrllvliC Cmk, LaaBaoinCrtKk,i^iiLuBCretk.aoDaro Crock QKk. Modia Agu, Cbico Manioea Cratk. Sail Cnck. BiUrr Cnck. &nlia(o Cmk. Livec^ Cieek. Ika Eimtdio Crack. Pinto Cretk. Tecuia Cncfc. Qnpenae Creak, Pailoha Creek. Tuna Crack, EJ hio Cnck, Tajon Cn< SmD\ca Creak. Cwou CrcEk. Guu CrackjATona) Creek. CaUoowood Caojrst. Fruidaeu Cratk. Pukwood Creak. Bu«u VUta Cnck. Billemlcf Creek, 90. Wlitafiinr. P<»o Cmk. R»4 Gulch. 72. YokoU Creek. Learii CnxbHoiac Crisk. T4. Ucnekila deck. RtltlMnake Creek. Stoke* Creek. Sud Creek. Wvtvke Credc Groty Cre«k. 80. Dry Creek. DaullOD Cmk. 82. DuUbmiu Creek. Dadmani Croak. 84, OweuB Cieck, Milca Cnxk. M. Bunii Cnek, Black Raeol Creak, Fahraoa Creek. 89, WildalCraek. Dry Cmk. 02, Mulclla Cmk, Bar Creek, Rock Creels Bii Sprint Creek, PcuhyaCrtck. OS Dr, Creek. n^lowCmtBotlcrCreet *•>-"**■ -^ 97. Konfo Creak. GbUIrm Creek. Sao Anlonio Creek. Adobe Cmk. Lyneb Cmk. Htuio Creek. Toliy Crwk. OS U'oill Vallry, Acua Calicata, Qookn Crc«k. attnit Cmk, .Sunt Canyon Creek. Sonoma Cmck. donama W). Conn Crmk Rector Canyon, Soda Creek .Millikao Oeek. Earco Creek. Tulway Cnek. Suaool Creek, [ako Cliabat S)ilrin. N«lh Bnncb Napa Cmk, South Braneb Nipa Creek. Dry Cmk, Sulpliur Snrinn. 100, &1U110 Creek, Uallii Cmk, Lod Creek. Gmn Valley Crock. Sulphur Spriup Crcii 101. Kirker Creek Ml, Diablo Creek, Walnut Creek. Redao Occk. Fioolc Creek. 107. hruaion Cnek, A[ui CUIcoLo Cnck, Ami Pri* Cree^ Torogu Cmk. Scott Cmk. Oalcnt Cnict .inoyo do loa Coebei, Berryeau Creek. Dry CrecL Silni Cmk. 111. lAaUatiB Cmk. San ToinuCre«k; Campbell Cmk. Calaboioi Cmk. Steniu Creek. IVmuDente Cmk, 113. IiUi Crock. SiD BruQD Creek. San Malw Creek, loutl Creek. BeUasDl Cmk, Tu'cu Creek, CordiUmi 125. Uul Cmk. Wade Creek, Ten Mils Cmk, Noyo Ririr. Bit Rinr, Albion Creek. 127, DoDshDe Creek. Elk Creek, Alder Creek, Bnub Creel, Ouoia River. Gualila River, 130, WBlkcr Creek. San ADlonJa Creek, ^luion Creek. 131. Bolioaa Creek. InteruD* Cieek, Olcma CrecL 136. Ebn Jacinto Hirer, Indian Creek. Foppelt Creek, PoUro Creek, Bsutiato Oeek. Cului Valley Cmk. " ~ ' "' Mill Crock. Sand Cmk, Cil/ Creek Plunio Crock, Stnwbcrry Croak. Walsrman Canyon, " Creek. Lylle Cioek. in A - - - jTCmitljii Chilton "cinyon. 13V, Pacoinu Cnck. Tuiuofk Cmk. Arroyo fno. LllUe Tujunci Canyon. 110. Dumo Crock. Ramgra Creek. Solallee Creek, CaUcClai Creek. Sycimoro CroJc, Arroyo Soquil. Trani Caoyaa, Miilibu River. Topanfa Crirk, Ruilio Crock). 141. Sanig, Paulo Creek Bspo Creek, Pini Creek, (^talc Creek. Hin FronoUauita Cmk. Douiiuut Creek. 141 Hincon Creek. San Antonio Cmk. Jolama Cmk. Qxida CmL 147. Uranda Creek, &d Luii Oblini Cmk. DiaUo Creek. CeOD Creek. lalay Crack, ftn UtmordD Cmk, Mu Cnck, Torn C^etk. VlQa Creek, Sasla Itcia Craek. Su Simeon Creak. Arrays if U Crui, Btt 8ur Creak, Ultle : Creek. C^naiJ Itiior, San Canajo River, Corral de Rolr* Creek, Bnuiolan Creek, Sterner Craek, PenoinclonOek, Son Lukito, Davi) Canyon, Wild Chrrry Caiiyoa, Oitbls Crayon. Uvtard Canvoa, Cioir Bar tWon. Pecho Creek. Willow Creek, Old Cmk. CuyaMB Creek. Pico Creek. Ultla P^eo Cmk. Biem Creek. Arroyo Boodo, Amyo de loa Chioi* Joabui Creek, Salmon Crt.fc Viili Cnet Alder Crwt WUlow Creek, PrertUtt Cmt, Wild CalUe Creek. Mill Cnck, Polo Colorado Ca^vn, Doud Creek, Wild Cat CrMk Oianite CooyoD, Milpaio Creek. Sobcnnea Cnek. 118. Toro Creek. Pine Canyon. Limcfciln Craek. Alial Craek, Quail Creek, fman't Crock. Johnafln anyoD. Arroyo Stco, Relli Cnek, Shirttad Cmk. Ckalono Creek. &n Culoa Canyon, Aqua Gnnde Cinyoa, Monroe ^Oyoo. ThomiHon Canyon. Branaletter Canyon. Pino CanyoB, Cherry Canyon, Kant Canyon, Seven Well Oonyon. Folia ^wod, EepinoiB Canyon, Uroadbunt Canyon, Barrel Can)vn, Sao Loreoio Creek. Snetwatei Canyon, Wild Hoih Oknyuo, Uanilton Canyon, Iaiii Valley Oeck. Pins Valley Creek, Redwood Canyon, Lyneb Canyon. SariODl Canyon, ^linii River, &n AdIouId Cnck. Nacimiuilo Rinf, Son Uarooa Cmk. Hucrhuero Creek. EilroUa Creek, Vineyanl CaoyOO, Stone l^!aoyon. liortteadero Cmk. U BnB Cmk, Oodfiik Creek. Little Arthur Creek. Vni Creek. Llaeu Cmk. Pacheeo Cmk. Arroyo de loa Yllnnii, .Irroyo doi Flchaea. Saalt Ana Crock, Tm Finis Creek. Sao Benito Cmk. Binj Creek. Sin Juan Creek. 160. San Vieeole CroV, Liddell Crmk. Rapid Cnek. Lofuna Creek. Coja Creak. Baldwin Creek. Mcder Cmk. Arroyo de lea Friiotm.Wli.le II suae Cmk. CucodaCmk. Omn Oab Cmk. Aao Nuovo Cmt Finny Croak, Qaio* Crest WadJcIl Crrek, Soult Creek. S»n Loranio Cmk, a-iuol Cmk..Apto> Creek. 151. rilaroiOB Cmk. Pu;iniiu Creek. Trinilai Crock. Son Gre«oria Croclc Fompoaio Cn«k. FeMadaro Clock, Lobltea Greet Freuebman'a CreeL Deniditoo Creek. Sen Yicanla Creek. San Pedro Creek. 151 Bulla Crack, Aulelepo Creek, ColLonwDod Cmk. Loel Binr. Dry Cmk. Coltoawood Qvk, Osl Cmk Raider Creek, Eadt OrMk. Bam Cmk. ISO. Hed R ' " ."..-- " . - . _ -^ ,. 117. Smoke , 158. Pine Creek. 160, Suaan River. Baiter Crtok. Lonj Valioy Cmk. „ , „ .^ . , , ~,. 160, Mtiff Creek. Ward Cmk. Blackwood Creek. Madden Creek. MsKlDDoy Cnek. Gcoeril Creak. Lonely Gnteh, Umw Truckoe Hirer, Taylor Cmk. 166. Mill Creek. '"liL-l* C.rj.yon. Leevi. 167. Chvdaipi (■-,■.■ ' ••-*■--..- r- Piute Creek, Sirot. < 191 Uwem H ■ 190 Pino Cro Fmnun Cntk. SL.-. Creek. Hod MouoUt, ■ ■ ■ ■ cCrett Pl ic Cnek, P»rta» Crtck. Ruib Cmk. Walker Csoyoo. -'■•• Marble Cmt, Cold«ler Canyon. Lone Tm Creek ifUner Creek. -luu-nLo Canyon. .UeUea Canjiin. Black Oayoo. ■■ n Crwk. ^^eC;« C»oyon. Birth Creek. B»b« Cmk. Rawaon Oek !■.; Pine Cmk. Liiil. Mn* Cmk. Binh Creek, War Cmk Tiaemaha . ..Jilg Cmk. Dit-inon Cnck. Sawmill Cmk. TbbaulCrecl. Oak CVeck. 'Ho^^clij CrljA&a.rii'cmk'u^ Creek. Hofhack Crect Lone Pine Creek. Tnlll. Ctwk. DleU Crwk. Rlchor Crrek. Carrol Creek. Cutlonmxd Cmk. Alb Creek. Braley Cmk. CorthaCD Creek. Ulaooba Creek. Walktf Creek. Summit Cmk, Hajne Creek, Hotbaek Cmk. 173 Amartaa Creek. LilUi Reek deck. BiK Rock Cmk. ISTi: Fki-liiB V. XI. WATER RESOURCES OF CALIFORNIA. 33 Of the basins of intermediate water productivity, the Sacramento and San Joaquin are about equal in relative storage requirements. Although the streams of the San Joaquin drainage have a much greater range in variation of annual run-off than those of the Sacramento, the bulk of the San Joaquin waters run off later in the season than those of the Sacramento, and so, in general, storage works are about equally effective in each basin. These two basins require slightly less storage capacity for equal relative results to that required by the North Pacific region, for the North Pacific region has the smaller summer flow in its streams. However, the relative storage requirements in these three regions are nearly alike. The San Francisco Bay region, because of its smaller fluctuation in annual run-off than the South Pacific, and greater than the Sacra- mento or San Joaquin, falls intermediate in effectiveness of storage on its streams, between the South Pacific region and the three great- est water producing basins of the state, in which storage capacity, on the whole, is nearly equally effective. Almost twice as much capacity in storage works is necessary in the San Francisco Bay region to gain equal relative results in equalizing its stream flow as in either of the Sacramento or San Joaquin basins. The relative amounts of storage required to equalize stream flow, largely pertain to the range in variation between years of maximum and minimum run-off and to the apportionment of the annual run- off between the winter and summer months. The North Pacific region has the smallest variation in annual run-off, and there the maximum' is only five times that of the minimum season. The maximum year in the Sacramento Basin is six times the least, while in all the other regions the variation is much larger than in these two. In the San Joaciuin it is fifteen times the least, in the San Francisco Bay region it is seventy times the least, and in the South Pacific the year of max- imum run-off is one hundred times the least year. While the San Francisco Bay region has the smallest portion of its waters wetting the stream channels during the summer months, the Great Basin drainage, east of the Sierras and southern California moun- tains, is distinguished by having the largest apportionment of summer flow of any of the six regions. The streams of the San Joaquin Basin are next in order and those of the Sacramento not far behind. The North Pacific region has an intermediate apportionment in the sum- mer months between that of the San Joaquin and that of the South Pacific region. Similar comparisons may be made between any of the individual drainage basins in the state by referring to Table I in the proper columns. The flow in all streams during the largest, the smallest, and the average season, as well as during the midsummer months, is there. Also the storage capacity required to equalize their variant flows and the size of extreme floods are enumerated. So, comprised within Table I, is a complete inventorj^ of all the waters of the state, which includes their locations, their quantities and their variabilities. The valuer entered in the table are averages for the past half century and should be indicative of future expectancies, so that this table pre- sents in full the water resources of the State of California with their characterizations. 34 WATER RESOURCES OP CALIFORNIA. CHAPTER V. UTILIZATION OF THE STATE'S WATERS. Only one-half of the wide expanse of California contributes much to the waters of its streams. The other half, lower in altitude and more even of surface, is favorably disposed for occupancy by man, and its populated sections need water in order that their industrial expansion may continue and their communal civilization progress steadily onward. The production of food, the generation of power, and the supply of water for domestic use, in the drier half of the state, are largely depend- ent upon the waters of the streams which have their source in the more elevated regions. The farmer relies upon the streams during the warm, dry summers for supplementary moisture to mature his crops and upon their hydro-electric energy to pump his irrigation waters. The electric energy, generated by the waters of the streams as they descend the mountains' slopes, furnishes power and illumination to the industrial centers, and light and heat and means of operating many conveniences, to the entire social state. But most of all, the cities, towns, and villages, the pleasures and comforts of their congregated peoples, require these waters in abundance for drinking and household purposes. The expansion of all these benefits to include larger popula- tions, demands increased supplies of water for the future with uninter- rupted service in purity and plenty, at all times of the year, and in all successive years alike. The vital importance of water in the economic development of Cali- fornia is succinctly shown in the history of the state 's production. By 1920, with but three per cent of all the people in the entire United States residing wdthin California's borders, this state, eighteenth in the area of land farmed, was fifth in position among the states of the Union in value of farm crops; and while in the eighth position in value of manufactures, was second in the installed capacity of water wheels for the hydro-generation of electric current. Since 1920, this state has advanced from fifth to fourth^ ^* among the states of the Union in value of agricultural products. The advance to so favorable a comparison in agricultural output with the other forty-seven states of the Union, has been made without any increase in the total area in improved farms. In fact, thirty-five years have elapsed since the aggregate area in improved farms in California has increased. Although there are twenty-three million acres of land susceptible of agriculture within the state's borders, the enlargement of the area tilled ceased when but half of the total had been brought under cultivation. As a result of the unprofitable farming conditions obtaining on the remaining millions of acres, the area under cultivation did not further enlarge ; the experience of the practical farmer limited the total area cultivated to but half the agricultural lands. Some "'Statistics of California State Department of Agriculture shoW that this state was exceeded in value of agricultural products by Texas, Iowa and Illinois. WATER RESOURCES OF CALIFORNIA, 35 additional areas having inadequate natural moisture have since been added to the total area of improved farms by developing accessory water supplies, but the abandonment of other areas previously farmed has compensated in their summation so that the total acreage in im- proved farms has remained practically unchanged for thirty-five years. This limit to the area in improved farms was reached in the year 1885, Prior to this year, the tilled area had expanded in leaps and bounds from the great impetus to farming enterprises that followed the world wide movement to this state after the discovery of gold at the midway point of the last century. This enlargement of the farmed area continued at a rapid rate for a third of a century, then slacken- ing, it ceased about 1885, With less than 12,000,000 acres cultivated, all of the state's agricul- tural area with sufficient natural moisture to mature a profitable crop had been brought into use. Since 1885, the state has had no additional area that could be profitably utilized for agriculture in its natural con- dition, so that in response to the continuing favorable market for agri- cultural products, a more intensive farming of the land already under cultivation has been in progress. All through these thirty-five years, the demand for products of California's agriculturists has never ceased to increase at an accelerated rate, California, favorably sit- uated, its fertile agricultural soils producing to capacity under condi- tions of dry farming, required only that additional water be applied to these lands to multipl.v their yield. The practical farmer, answer- ing to the ever-enlarging market for his products, increased the yield of many acres by supplementing the soil's natural moisture with water applied through irrigation. In this way the state has continued, through the last thirty-five years, to respond to the constantly increas- ing demand for its farm products, and in this way the potent possibil- ities of California's farm lands are being invoked to a yield greater in value than in any other state of the Union. The utility of the state's waters in augmenting the yield of its agri- cultural lands and the demands of the future, may best be ascertained through an investigation of the use of water in the past. The quan- tity of accessory water needed for gro\^^ng crops to an harvestable maturity, may best be derived from the results of experience and prac- tice. California's lands, .deficient in natural moisture during the grow- ing season of agricultural plants, have received varying quantities of water. The amounts applied on the sundry tracts in the divers locali- ties, differ widely with all the circumstances and conditions affecting the use of water. The application to different fields has varied greatly even for like crops, for not only do the quantities of water used vary with the incentive for their economic application, but the amounts that are dissipated in the process of irrigation change greatly with contin- gent circumstances, and even the actual quantity necessary for absorp- tion by the root systems of the plants, is conditional. These circumstances and conditions neces.sitating the application of more or less accessory water, are so vast in number, changing with every variation in soil, crop, and preparation for spreading water, that on small tracts of land, the effect of one may predominate, but on greater areas they tend to neutralize in effect. For this reason the average use of water on very large areas approaches like figures, while the use on small tracts within these large areas, may take wide numer- 36 WATER RESOURCES OF CALIFORNIA. ical departure from the general average. The larger the areas com- pared, usually the closer is the agreement of numerical values in the records of use. From the average use of water on large areas, suffic- iently great to suppress the predominance of effects peculiar to small parcels, natural divisions of the state, sixteen in number, have been evolved, and called duty of water sections. These sections comprise within their boundaries, lands of approximately like geographic posi- tion, similar surface conformation, of analogous economic environment, aud equal climate, and so form convenient segregations for the dis- closure of the irrigation requirements of California's agricultural lands. Delineated on Plate III, "Map of Agriculture Areas and Duty of Water Sections," the boundaries of these sections show as red lines following natural dividing conformations of the land surface. The agricultural lands show as light green areas within the delimiting red lines. Letters within circles, interspersed throughout the green areas, indicate the location of individual irrigation systems or of divers tracts of land for which data on the actual use of water or on proposed uses, have been collected by these investigations. A searching inquiry of the use of water has been made and water measurements have been assembled appljnng to an area that equals more than half the lands irrigated in the entire state during 1919. These records are the sum- mation of the labors of a great many engineers and hydrographers that cover the major portion of the last two decades. These extensive data are included with pertinent material in Appendix "B" to this report and the letters within the circles on the map, are attached to the data on the plates and in the tables of this appendix, so that the approximate geographic situation of the lands to which the data apply may be traced. That the water requirements for each of the several sections of the state might be derived from this great assemblage of information, an examination of the circumstances and a close scrutiny of the condi- tions were made, surrounding the use of water in each section. All information on the types and fertility of soils, the crops grown, the climate, the water supply, the surface conformation of the land, and all other subjects related to irrigation requirements, was reviewed and compared with the measured and proposed uses of water. Prac- tical working quantities required of accessory water supplies in each section, were so evolved and recorded in "Table 2, "Agricultural Area and Net Duty of Water in the Sixteen Sections of California." The total area of agricultural land in each section is also recorded in this table and numbers. are given to each section that show their location on the map, Plate III. These practical working quantities in Table 2 that set forth the general water needs of the agricultural areas in each section, are expressed as the amount of water required on a unit area of cropped land and are named the "Duty of Water." Originally an expression for the area of land that a measure of water would irrigate when flowing continuously through the irrigation season, custom has inverted the first meaning and more conveniently utilizes the term "Duty of Water" to name the quantity of irrigation water required to furnish throughout one season, an adequate supplementary supply to the soil moisture on a unit area of land. This quantity is usually expressed as feet-depth on the land, meaning the depth that the total amount of water required each year for one acre, would cover its surface if it WATER RESOURCES OF CALIFORNIA. 37 TABLE 2. AGRICULTURAL AREAS AND NET DUTY OF WATER in sixteen sections of California, shown on Plate III Section number. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Description of section. Los Angeles area, Ventura to Redlands San Diego area. Mexican boundary to San Jacinto and Yucaipa Imperial, Coaohella an4 Palo Verde valleys Antelope Valley and Mojave River areas Inyo-Kern, Owens and Mono valleys Sierra foothills and rolling plains east and south of San Joaquin Valley floor San Joaquin Valley floor Western slope of southern San Joaquin Valley Santa Barbara, Santa Maria and San Luis Obispo areas Salinas and contiguous valleys Santa Clara and adjacent valley areas Delta lands of San Joaquin and Sacramento valleys Sacramento Valley floor Sierra foothills, and rolling plains east and west of Sacramento Valley floor. North coast area Northeastern mountain-valley and plateau areas Total Agricultural area. Net duty of water. Acres. Feet depth on land. 1,310,000 1.75 84.000 1.25 1,299,000 3.00 1,107,000 2.00 657,000 2.50 ' 1,800,000 1.75 5,468,000 2.00 971,000 1.75 410,000 1.50 296,000 1.75 530,000 1.50 453,000 1.50 2,694,000 2.25 2,305,000 1.50 624,000 1.25 1,598,000 1.75 22.506.000 WATER RESOURCES OF CALIFORNIA. 37 TABLE 2. AGRICULTURAL AREAS AND NET DUTY OF WATER in sixteen sections of California, shown on Plate III Section number. 1 2 3 4 5 6 7 8 9 10 11 12 13 It 15 16 Description of section. Los Angeles area, Ventura to Redlands San Diego area. Mexican boundary to San Jacinto and Yucaipa Imperial, Coachella an(j Palo Verde valleys Antelope Valley and Mojave River areas Inyo-Kern, Owens and Mono valleys Sierra foothills and rolling plains east and south of San Joaquin Valley floor San Joaquin Valley floor Western slope of southern San Joaquin Valley Santa Barbara, Santa Maria and San Luis Obispo areas Salinas and contiguous valleys Santa Clara and adjacent valley areas Delta lands of San Joaquin and Sacramento valleys Sacramento Valley floor Sierra foothills, and rolling plains east and west of Sacramento Valley floor . North coast area Northeastern mountain-valley and plateau areas Total Agricultural area. Net duty of water. Acres. Feet depth on land. 1,310,000 1.75 84.000 1.25 1,299,000 3.00 1,107,000 2.00 657,000 2.50 ' 1,800,000 1.75 5,468,000 2.00 971,000 1.75 410,000 1.50 296,000 1.75 530,000 1.50 453,000 1,50 2,694,000 2.25 2,305,000 1.50 624,000 1.25 1,598,000 1.75 22.506.000 38 WATER RESOURCES OF CALIFORNIA. were all accumulated and confined above that acre. Conventional use, however, has resulted in dropping the unit of area, the acre; and of time, the year; and although not expressed, these are now implicitly contained in the phrase "Duty of Water." Qualifying terms are in common use, such as "Net" and "Gross." "Net Duty" is the quantity of water measured at the point nearest to its entry and spreading out upon the cropped land. It thus con- tains the water required for plant growth, together with the spreading or application losses and the losses contingent to storage in the soils prior to absorption by the roots of plants.' The "Gross Duty" is this same quantity of water in lake or flowing stream, reservoir or place of storage, together with the conveyance losses and waste over spillways incident to its flow through canals or conduits from the first point of diversion at its natural source, to its point of entry on to the cropped soil. "Net Duty" of water is best adapted to considerations of the requirements of accessory water supplies and in comparing the needs of different localities. "Gross Duty" is a subject for consideration in canal and conduit design and in initial diversion quantities. The application of waters to large areas in the quantities tabu- lated at "Net Duty of Water" in Table 2, provide adequate moisture for their intensive cultivation ; but in estimating the total water requirements in any locality, portions of the entire area will not need Avater. Contingent to an intensively developing agricultural com- munity, the rural and urban dwellings, routes of communication and transportation, industries, and improvements, occupy an increasingly large portion of the total area. As the small farm holdings become greater in number, the land is more vigorously cultivated and the production per acre is enhanced ; the farm buildings needed for this great activity occupy a larger proportion of the cultivatable area. The total value of improvements, the wealth created and the income derived from agriculture vastly increases, but the farmed area would tend to diminish except for the cultivation of new areas previously unprofitable to farm. The inclusion of new areas among the tilled lands, however, is limited, for after the entire area is l>rought into use, no additions can be made without destroying improvements which themselves are essen- tial for the tilling of the soil, and also, there are always some lands naturally unfit for cultivation, such as rocky and alkali spots, high knolls and stream beds. These will never be irrigated. Further, in each season a portion of the total area will remain fallow, other por- tions Avill be planted but not watered and irrigation water will not be required for either. So, in closely settled irrigated communities, the sum total of the unirrigated lands may be a considerable part of the total area. The studies made in these investigations, indicate that the part of the gross area ultimately requiring agricultural water, is from sixty to ninety per cent iii the various sections of the state. Of all the waters in use for the various purposes of civilization, that employed in agriculture is predominant. In the year 1920, with three and one-half millions of people in California and one-quarter of its arable lands under irrigation, about one-fourth of all waters that can ultimately be made available through storage within the borders of the state, were in use for domestic and industrial supply, irrigation, power generation and mining. The domestic and industrial use was about four per cent of the total, while much of the Avaters used for generating electric power and in mining, being on elevated lands, was employed a second time at lower levels in irrigating the state's dry soils. WATER RESOURCES OP CALIFORNIA. 39 CHAPTER VI. COMPREHENSIVE PLAN FOR ACHIEVING THE MAXIMinVE SERVICE FROM THE WATERS OF THE STATE. Plans for converting the waters of California to their greatest service in this generation and for all posterity, must give precedence among the many uses for water, to those purposes which are indispensable to man's continued existence. "Water for drinking and household use takes priority over that for growing food-stuffs, while water for growing food-stuffs is primary to that for industrial purposes. "Were there abundant water for all needs, cognizance of its relative importance in domestic, agricultural and industrial service, could be disregarded. In California, however, where the waters in the streams are replenished by rains that largely occur in a few months of the year, and seasons of meager or bountiful rainfall succeed each other in all variations of sequence, there would be deficiencies of water for present needs during every season, were it not for impounding M'orks already constructed. Only through the construction of still greater and more elaborate works to equalize the erratic stream tlow and to transport waters to localities of urgent need, can California continue to enhance its wealth and increase the numbers of its people at the prevailing rate which for the past decade has exceeded that of all other states of the Union but two.^^' The combined increase of population in these two states, however, was only one-third that in California. A comprehensive plan must primarily insure a full supply of water for drinking and household purposes. But since the present needs for domestic and industrial water supplies are only a twenty-fifth the amount required for irrigation of the agricultural lands now using water, the principle constructive features of a plan for obtaining maxi- mum use of the state's waters, must revolve about its distribution for the greatly preponderant use in agriculture. Further, the magnified urban communities of the future must largely encroach upon lands now classed as agricultural, for these farm areas comprise all the lands that are suitable for residence, except those about the state's seaports. Because of their harbors, commerce and strategic locations, the seaports will expand over adjacent lands now excluded from the agricultural areas on account of being scatteringly settled fringes to population centers or on account of being too rough of surface or steep of slope. But metropolitan areas in all other parts of the state will undoubtedly arise upon the flatter lands classed in this report as agricultural. As these are relinquished for city development, the total consumption of water in any district for both domestic and irrigation supplies will not increase very much, since cities of fairly mature growth use water about "'U. S. Census — 1920. Population of Arizona increased 63.5 per cent, Montana 46 per cent, while California increased its numbers 44 per cent during the preceding d' cade. 40 WATER RESOURCES OF CALIFORNIA. equal to that required for irrigating crops on the same area. Conse- quently any comprehensive plan for supplying water to all parts of the state in amounts suited to its future needs for urhan and agricultural development, will have accomplished both purposes when all the present lands, classed as agricultural, are provided with an adequate- allotment of water to irrigate their surface, and additional allowances are made for the dense urban development that will occur about the state's seaports. Of other uses for water, though subservient to the primary demands of the household and for growing food-stuffs, that of generating hydro- electric power to light and heat the homes in rural and urban communi- ties, to operate factories, railroads and car lines, to illuminate the streets of cities and to"RTis. as well as to pump and deliver water for the domestic and agricultural use, undoubtedly ranks close to the employ- ment for agricultural purposes. It is through these agencies that accessories to raising food-stuffs are supplied, that farm produces are prepared for consumption, and the necessities and conveniences of civilization are conveyed to all alike, so that a comprehensive plan to obtain the maximum use of the state's waters must dispose of these waters in such a way that a full measure of hydro-electric energy may also be generated. The agricultural lands of the state, situated on the lower levels, are favorably located to receive the flowing waters of the streams after they have exhausted their inherent energy in tumbling down the steep moun- tain slopes. Three-fifths of the agricultural area of the state is less than five hundred feet in elevation, and seven-eighths of it is less than twenty-five hundred feet in elevation, while the mountainous water- producing region ascends to heights as great as ten thousand feet above the twenty-five hundred foot level. This spacious region, a steep and rugged country that spreads over half the state, yields practically all of California's waters. These drain into the stream channels and flow past the bulk of the lower-situated agricultural lands in their descent toward the ocean. Thus, the region that abounds in the sheer declivities and swift flowing streams, most essential for the generation of hydro- electric energy, lies above seven-eighths of California's agricultural lands and above those areas that will be mostly occupied by urban development. If the diversions of domestic and agricultural waters from the streams are generally confined to points below the twenty -five hundred foot contour, the areas most favorable for power development one-half the total surface of the state, with its waters nearly all of the state's suppl}^, remain intact for the unimpaired generation of electric energy and these waters may then be re-used on the lower levels for domestic, agricultural and industrial purposes. Therefore a compre- hensive plan to serve the maximum area of agricultural land with irriga- tion water, that makes its diversions of water below the twenty-five hundred foot elevation and that provides additional waters for the growing urban communities about the seaports that are not spreading over agricultural lands, is the constructive measure that will enable the greatest use to be made of California's water resources, and such a plan would give the greatest service to the primary needs of man and provide domestic and irrigation waters in their largest amounts, without WATER RESOURCES OF CALIFORNIA. 41 particularly abridging the use of waters for the industries and the generation of electric power. While the entire amount of California's waters for an average year would submerge the twenty-three million acres of tillable land in this state to a depth of three and a quarter feet if evenly spread over and confined above them and the necessary application to the soil is but two feet in depth annually as a statewide average, still the disparity in location of these agricultural lands with respect to the sources of abundant water supply, presents insurmountable obstacles to the utiliza- tion of a considerable part of these w^aters on the lands that need them most urgently. In northwestern California lies the area most productive in water of all regions in the state, the North Pacific Coast region. From the evergreen slopes of its timbered mountains, more than one-third of all the state's waters drain off into the ocean, passing on their couree, only two per cent of the agricultural lands of the state. This immense volume of water, enough to cover the arable lands of the entire state to an average depth of one foot ever}^ year, joins the ocean deep without opportunity of infusing harvest-maturing moisture into those portions of California's soils that are too dry for maximum production without accessory supplies. The oceanward slopes of the Coast Range are separated by more than one hundred miles from the nearest large body of farming land that is deficient in local waters. In attaining heights in an unbroken barrier of from four to nine thousand feet, the Coast Range IMountains effectively block the transportation of the waters from their western slopes to the extensive area of agricultural lands lying to the east and south. Only in projects of great magnitude can portions of these waters be captured and delivered for use on the lands that need them. Diagonally across the state from this great waterproducing basin of the North Pacific Coast, lies a region in the southeastern corner of California, one-fifth the entire area of the state, mountainous for a large part, but containing at least four million acres of flat lands of which the geography is only partly recorded because of the extreme aridity and uninviting aspect of its parched expanse. Some of the flat lands that skirt the edges of this moistureless solitude, have been fortunate in securing waters for their dry soils. These have responded to irrigation, and their great fertility has brought forth bountiful harvests to repay the pioneer. There were 546,000 acres of this region so irrigated in 1920. However, an area of 2,400,000 acres of the flat lands have been listed as agricultural, for water may ultimately be obtained for considerable areas in this region. Thus in one comer of California, one-third of its water resources are dissipated into the ocean with but small possibility of use, while in the opposite comer of the state, over six hundred miles distant, considerable areas of poten- tially fertile soils await the import of plant-nurturing waters to awaken their powers of production. Intermediate in geographic position between these extreme regions, lies the Great Central Valley containing three-fifths of all the agricul- tural lands of the state. The northerly part of this area, the Sacra- mento Valley, contains five and one-half million acres of agricultural lands and enough water courses through the streams traversing it, to 42 WATER RESOURCES OF CALIFORNIA. submerge these lands on an average four and one-half feet in annual depth ; while its southerly part, the San Joaquin Valley, contains eight and one-quarter million acres of arable land, but only enough water flows in its stream to cover them a foot and a third in average depth if spread evenly over them each year. To the west and south of these lands and disposed along the coast from San Francisco to the Mexican boundary, is the South Pacific Coast region, which contains a tillable area of over three million acres, but its streams on an average, yield only water enough to cover these lands a little more than one foot in depth annually. Other agricultural lands, about a half million acres in the San Francisco Bay Region and four and one-half million acres easterly from the Sierra Nevada and the mountain range extending southerly from Tehachapi Pass, have water in adjacent streams that will cover them annually to less than an average depth of one and a quarter feet, excepting those areas that can receive water from the Colorado River. Areas that are irrigable from the Colorado River may obtain amounts more than double this. To evolve tvorks hy which ivatcrs may he transported to overcome this wieven geographic distribu- tion of California's ivaters, so that, as 7iearly as possible, all these diversely situated bodies of agricultural lands may be served with their needed ivaters at the least expense, is the mai^i problem to be solved in unfolding the comprehensive plan. However, other most important coiLsiderations intervene in pre- paring plans. In addition to the seventy-three milljon acre-feet of California's waters being located in geographic positions adverse for use on much of the agricultural lands, these waters course down their stream channels in capriciously erratic rates of flow and three-fourths of them reach the lower levels at a season of the year during which they are of little use for irrigation, because the same storms that pre- cipitate the run-off on the mountain collecting areas, usually wet the lower agricultural lands as well. Thus works must be provided to detain large volumes of flood waters on their catchment areas and hold them in reserve for supplementing the diminishing summer flow of the streams at the time needed for irrigation. In holding waters in storage for later use, evaporation is continually active on their surfaces and the stored vohunes are constantly depleted through loss to the atmosphere. It is revealed by these investigations that, even with unlimited storage capacity available on every stream, not more than eighty per cent of the state's waters can be brought into use as uniform floAv; that, with maximum equalization of stream flow, one-fifth of all the waters would be lost by evaporation while being detained in reservoirs until the time arrives for their use. Thus the four great basins deficient in waters for their agricultural lands, the San Joaquin Valley, the South Pacific Coast Basin, and the regions of San Francisco Bay and of the Great Basin drainage, within w^hose confines lie two-thirds of all the agricultural lands of the state, would have their already inadequate waters, if developed in their entirety, reduced one-fifth in volume by losses of evaporation. To further complicate the problem, the waters of some streams, in their flow being less erratic, can be more easily equalized to uniform discharge than in others. To minimize the cost of the works, those streams must be most heavily drawn upon for water that require the least storage capacity to equalize their flow and upon whose drainage WATER RESOURCES OF CALIFORNIA. 43 areas cheap reservoir sites may l)e found. Tlie capacities of storage re(iiiired to yield the maximuin amount of uniform flow for irrigation use varies widely on the different streams. On the streams of least requirements, the maximum development may be obtained with a storage capacity whose volume is less than the annual yield of uniform flow, while on the streams of greatest requirements, a storage capacity fifteen times as large as the annual equalized flow is necessary to obtain the maximum yield. In general, the greatest storage requirements are on streams in the regions of least water production, so that the most effective use of the state's Avaters may be accomplished only through a superlatively scientific plan. That the highest attainments of science could be introduced in the preparation of a comprehensive plan, the investigations have assembled masses of data and completed intricate analyses concerning the location, the quantities and the variability of occurrence of the waters of the state. This digest of information has been all-inclusive, and is pre- sented in full in Appendix "A" to this report. It is summarized in Table 1, "Water Resources of California." This audit of California's waters results in the first complete inventory of the waters of an entire state that has ever been assembled. In addition, data on twelve hundred and seventy reservoir sites have been examined and preliminary estimates of the reservoir capacity and of the water yield were made on nearly eight hundred of these. The field parties of the department made reconnoissance surveys of one hundred and seA^enty-six reservoir sites and searched three thousand five hundred miles of stream bed for other possible locations. Further, that the amounts of water needed for irrigated agriculture might be ascertained, data were gathered on the quantities of water used on over two million acres of irrigated lands in the state, or more than half the total area irrigated in 1920. These records of water use extend over an average of four years. They are presented in Appendix "B" to this report. An analysis of all this data discloses that four-fiftlis of all the agri- cultural lands of the state may be watered. Additional investigation would probabh' result in finding means of irrigating still larger areas, but the water would be very costly. The 18,000,000 acres which it is found possible to water is an expanse greater than the entire area in all the western states irrigated in 1919. and three times as large as the area under water in California in the same year. To accomplish the irrigation of this large area will require the con- struction of reservoirs having an aggregate capacity of 50,000,000 acre feet, and many miles of large canals to transport water from its source to the regions of need for it. Because of the inclusion of the maximum area in the estimates of cost, the average price per acre for accomplish- ing the irrigation of the 18,000,000 acres is greater than most projects that are now under construction, but additional areas to those watered at the present time can only be irrigated at greater costs, for they are the residual lands as the more favorable areas for constructive enter- prises are selected. Quoting from the 1919 report to the Smithsonian Institution on irri- gation in the western states, "The great bulk of the land west of the hundredth meridian which is not too high, cold, or rocky for agricul- ture, is arid. Of this arid portion, over 15,000,000 acres have been 44 WATER RESOURCES OF CALIFORNIA. placed under irrigation by private or public enterprise, and in carry- ing out this work, of course, the most favorable opportunities for such irrigation have been developed. It will still be possible to add many million acres to the irrigated area and perhaps to double the area now irrigated, but this must generally be done at a high cost, as the cheap opportunities have been long since exhausted. There are remaining, however, many areas which can be irrigated within feasible costs aad will develop values far in excess of the necessary expenditures." These investigations show that it is possible to complete the irrigation of 18,000,000 acres in California alone. This would add 12,000,000 acres to the area under water in the western United States. In preparing a general plan for this attainment, the complexly involved rights and claims to I'iglits for the use of water in this state were not considered, but rather a i)lan was devised which comprehends the state as a virgin territory with its waters and soils unsegregated in private ownership. However, inclusion was made of all constructed works, so that the plan does not coutain proposals for discarding monu- ments of attainment of this or preceding generations. The plan would use all existant reservoirs, main canals and distribution ditches. Waters from new sources would be turned into the systems now in use on their arrival in that locality. In the estimates of cost, entries were included for expenditures made in building all existing works except distribution canals, so that the total cost estimated is for a complete, system of storage works and main canals giving uniform service to all lands irrespective of their present stage of development. It was found to be impossible in a general layout to separate the service and costs between areas now under water and those yet to be irrigated, because large areas, now classed as irrigated lands, have supplies that are deficient during the latter part of summer and many projects are short of water during the entire season in years of subnormal stream flow. To make this segregation would require a detail design of the plan in each locality, a work of great magnitude for so large an area as 18,000,000 acras. Therefore the cost estimates here given are the average cost per acre to develop a first-class water supply for all irrigable lands, whether they are now watered or not. They include all costs of construction and of rights of way, for storing waters and transporting them into the regions of use, but do not include the cost of constructing distributing canals or of operating the works, or the costs of acquiring water-rights, of litigation over claims to water- rights, or of damage suits. Neither have credit allowances for power that might be developed at or in the vicinity of the many dams for storing water been deducted in the cost estimates. The average cost of storage worlcs necessary to develop a full supply for the entire 18,000,000 acres, through all seasons without shortage, is twenty-five dollars per acre-foot of water developed, while the cost to the laud for adequate amounts would be forty-five dollars per acre. The cost of canals with appurtenant structures to transport this water to the regions of use would average thirty-five dollars per acre. The total average cost per acre to deliver a first-class supply to the region of use is, therefore, eighty dollars. These costs vary greatly in the different localities. WATER RESOURCES OF CALIFORNIA. 45 To effect the watering of so large an area at these costs, it is neces- sary over the bulk of California's lands to adopt a coordinated scheme of development and distribution of water, that comprise very large areas in interrelated works. To store the waters at the cheapest loca- tions of abundant supply and transport them long distances to the localities of use requires inter-service works of great dimensions. Areas greater than are now under irrigation may be watered without coordi- nated development and distribution, but a limit is being approached whereby united endeavors almost statewide in extent will be necessary to secure greater service from the state's waters at reasonable costs. The plan herein set forth requires complete coordination of the dis- tribution of water over large areas, as well as in the construction of the works. This is necessary in order to utilize the inexpensive storage sites to the greatest advantage. Dam sites of low cost often have lim- ited catchment areas draining into their reservoirs that do not yield enough water to warrant the construction of high dams when the draft on them is uniform. But under the coordinated scheme of oper- ation of the comprehensive plan, these dams may be erected to their full height and the cheap storage capacity thus created, utilized to the same advantages as the capacities behind other more expensive dams. To secure this advantage requires that the draft on all reservoirs be pooled so that in apportioning the total draft between the reservoirs in each season, the largest amounts may be taken from the reservoirs that are filling the quickest. In this way, the draft may be appor- tioned to small reservoirs situated on large drainage areas so as to empty them more than once a season and thus use excess water that otherwise would flow over their spillways; similarly, reservoirs with watersheds of small yield may be left to fill with accumulating waters during the seasons of plenteous run-off and ma}' be drawn on only dur- ing the drier seasons. In so apportioning the draft, exactly the same results are attained in irrigating the land as by the customs in present use whereby the waters from each reservoir become attached to a particular tract of land and the reservoir is drawn on regularly each year at its maximum rate of yield. Under this prevailing system of individual reservoir-draft it would be useless to build dams to greater heights than is required to equalize the flow of their tributary drainage area for a uniform draft, because no greater yield would be obtained with the higher dams. But when their waters are utilized for over year storage only, for hold- ing over the surplus of wet seasons to dispense it for use in the dry ones that may come several years later, these cheap reservoirs answer just as well as the more expensive ones with larger drainage areas. In either case the same amount of water must be held in storage some- where for the same length of time, but a great advantage in cost is gained over the customary system of individual reservoir-draft, by the selection of the cheapest sites for storing this water under the sys- tem of pooled draft. The scheme of pooled draft of the comprehensive plan, allots the total draft to the various reservoirs so that the greatest efficiency is attained in operating the works. To obtain equal yield to that of the customary system of individual draft on reservoirs, the coordinated scheme of pooling the draft contained in the comprehensive plan, would result in an average construction cost of storage works only slight!}' more than half that of the individual reservoir-draft system. 46 WATER RESOURCES OF CALIFORNIA. The preliminary comprehensive plan outlined in this report will accomplish the irrigation of the maximum area of the state's agricul- tural lands at the least cost, as well as provide waters for the primary use of domestic supply and leave the great mountainous area above the twenty-five hundred foot contour free for the generation of hydro-elec- tric energy, except for the irrigation of the beautiful mountain valleys, that dot these regions and the table lands in northeastern California. Their total area, however, is only one-eighth of all the tillable soil. On the other hand, much power can be generated below the twent^'-five hundred foot level and above the irrigation diversions, especially at the high dams of many of the storage reservoirs. This plan, then, outlines a scheme that will obtain the maximum service from the waters of the state and provide for all users in order of their importance to man's continued existence. In this plan the source of supply has been selected as close to the needy land as possible, the least expensive storage sites have been selected, and the canals have been routed over the least obstructed paths and a scherae of coordinated use of reservoirs has been included that makes it possible to attain the most efficient service in their operation. The main features of the plan are delineated on the map of California Plate IV, "Preliminary Comprehensive Plan for Maximum Develop- ment of California's Water Resources." Because of the physical limits which the mountain ranges and great distances in California place on the transportation of water, bounds are placed on the areas that naturally group together to their mutual advantage quite like the bounds of the great drainage basins of the state. The plan will therefore be described by ma.jor drainage groups. SAN FRANCISCO BAY DRAINAGE. Half the waters of the state in their natural course drain into San Francisco Bay. From the Pit River, which rises in the extreme north- east corner of the state, to the Kern, three-fourths the length of the state towards its southern extremity, these waters gather into the Sacra- mento and San Joaquin rivers to join with smaller streams that empty directly into San Francisco Bay, in issuing through the Golden Gate into the Pacific Ocean. Within these drainage basins are 14,800,000 acres of lands suitable for agriculture. The comprehensive plan pro- vides for irrigating all but two and one-half per cent of this entire area. Only 4,260,000 acres are now irrigated in these regions. Ninety-five per cent of the 14,800.000 arable acres in these basins lies in one large continuous body of land on the floor and skirting the edges of the Great Central Valley. Sloping from elevations of five hundred feet above sea-level at the extreme northerly and southerly ends, these lands are barely higher than the sea in the central parts. With an extreme length of five hundred miles, the economic conveyance of the surplus waters of the north half of this valley to the southerly areas that are lacking in water, demands that the plan be adapted to the nat- ural topographic and hydrographic features of the area. Since seven-eighths of all the waters of these regions drain off the Sierra Nevada Mountains, there is ample for spreading on the easterly side of the valley. In the Sacramento Valley, the east side lands would be served almost entirely by gravity diversions from adjacent streams iSii,tiiiiii{iiiliii| Jl; ^1 I nt 38Z3s&S3SF:[:r3e:3st:ei:s=i]a3asi£as I r I I _ 2| I S^S'»;SSS;3S3S5^5$3«SS33SU3S8 /r\ r^ £) WATER RESOURCES OF CALIFORNIA. -47 and the main canals would be short, but southerly from the American River, a series of five long canals would be necessary in order to com- pletely irrigate the areas eastward from the valley trough. These canals generally would be on the valley floor and serve to transfer Avaters southerly as they cross the distributing canals now in use. Byni this means all of the east side of the San Joaquin Valley may be servedj by gravit3^ The westerly side of the Great Central Valley is deficient in local waters, particularly in the San Joaquin where their average annual amount is only 250,000 acre-feet. Their full amount, however, would be distributed by gravity to the higher lands on the edge of the valley floor. In the Sacramento A'alley, three canals, each some sixty miles in length, would divert from the main channel of the Sacramento River and spread water to the south and west, but a very considerable area would be served by pumping diversions with comparatively short main canals leading to adjacent lands. jMany of these are already con- structed. Some areas to the w^est of the gravity canals would also be served by pumping from these mains. The pumping lifts would gen- erally be less than fifty feet. The west side of the San Joaquin Valley would be served by one grand canal two hundred miles long. This would follow the flat lands of smooth surface and have nine pumping plants at intervals along its course to raise the water against the natural grade of the valley floor. The greatest lift of the water flowing in this canal to its extreme southern end, would be 400 feet. There would be 650,000 acres served out of the grand canal by gravity, but the other 1,380,000 acres that could take their supply from this canal, require that the water be lifted by pumping for distribution over the land surface. The total pump- ing lift would be high for most of these lands. About 600,000 acres only would have a total pumping lift of less than three hundred feet, 1,100,000 acres between three and six hundred feet, and 350,000 acres a lift of more than six hundred feet if they are to be watered. As great as these pumping lifts would be, this plan of distributing the water is much less costly than one of gravity conveyance. To import water to this area by gravity, would require a canal of large dimensions, tortuously following a grade contour on steep mountain hillsides and winding in and out around every rocky spur and into each receding ravine. The total length attained in its devious route would double or treble the air line distance of five hundred miles between the source of supply in the Sacramento River and the extreme southerly lands to be watered. The cost of constructing crossings for a gravity canal at the innumerable drainage channels that it would intercept, alone would probabl,y exceed the total cost of all the works of the com- prehensive plan. In the comprehensive plan, the excess waters of the Sacramento drainage basin would be collected in the main river channels and, by means of a dam across Carquinez Straits below the mouth of both the Sacramento and San Joaquin rivers, this water would be diverted into the lower San Joaquin River from which the grand canal would take its water. Thus the cost of conduit would be obviated for the full length of the Sacramento Valley. The grand canal would follow the smooth valley floor and its excavation would be the cheapest type of WATER RESOURCES OF CALIFORNIA. -47 and the main canals would be short, but southerly from the American River, a series of five long canals would be necessary in order to com- pletely irrigate the areas eastward from the valley trough. These canals generally would be on the valley floor and serve to transfer waters southerly as the}" cross the distributing canals now in use. By]! this means all of the east side of the San Joaquin Valley may be servedj by gravity. The westerly side of the Great Central Valley is deficient in local waters, particularly in the San Joaquin where their average annual amount is only 250,000 acre-feet. Their full amount, however, would be distributed by gravity to the higher lands on the edge of the valley floor. In the Sacramento Valley, three canals, each some sixty miles in length, would divert from the main channel of the Sacramento River and spread water to the south and west, but a very considerable area would be served by pumping diversions with comparatively short main canals leading to adjacent lands. Many of these are already con- structed. Some areas to the west of the gravity canals would also be served by pumping from these mains. The pumping lifts would gen- erally be less than fifty feet. The west side of the San Joaquin Valley would be served by one grand canal two hundred miles long. This would follow the flat lands of smooth surface and have nine pumping plants at intervals along its course to raise the water against the natural grade of the valley floor. The greatest lift of the water flowing in this canal to its extreme southern end, would be 400 feet. There would be 650,000 acres served out of the grand canal by gravity, but the other 1,380,000 acres that could take their supply from this canal, require that the water be lifted by pumping for distribution over the land surface. The total pump- ing lift would be high for most of these lands. About 600,000 acres only would have a total pumping lift of less than three hundred feet, 1,100,000 acres between three and six hundred feet, and 350,000 acres a lift of more than six hundred feet if they are to be watered. As great as these pumping lifts would be, this plan of distributing the water is much less costly than one of gravity conveyance. To •' import water to this area by gravity, would recjuire a canal of large dimensions, tortuously following a grade contour on steep mountain hillsides and winding in and out around every rocky spur and into each receding ravine. The total length attained in its devious route would double or treble the air line distance of five hundred miles between the source of supply in the Sacramento River and the extreme southerly lands to be watered. The cost of constructing crossings for a gravity canal at the innumerable drainage channels that it would intercept, alone would probabl}' exceed the total cost of all the works of the com- prehensive plan. In the comprehensive plan, the excess waters of the Sacramento drainage basin would be collected in the main river channels and, by means of a dam across Carquinez Straits below the mouth of both the Sacramento and San Joaquin rivers, this water would be diverted into the lower San Joaquin River from which the grand canal would take its water. Thus the cost of conduit would be obviated for the full length of the Sacramento Valley. The grand canal would follow the smooth vallej' floor and its excavation would be the cheapest type of 48 WATER RESOURCES OF CALIFORNIA. earth work. It is so designed that by utilizing the storage capacity of Tulare Lake, the pumping plants along its course may operate eleven months in the year, resulting in a considerable reduction in size of canal and of pumps. The waters pumped during the winter months would be stored in Tulare Lake for use the following summer. No flood menace would be involved in filling the Lake during the winter with the comprehensive plan in operation, for the complete develop- ment of both the Kings and Kern rivers would absorb in their reser- voirs, the flood flows that occasionally fill this lake. In general, there is opportunity to generate ample electricity for the pumping required in the comprehensive plan, at the dams of storage reservoirs distant less than one hundred miles from the pump- ing stations. The total cost of these generating works would be very much less than the difference in cost between the canals and pumping plants of the comprehensive plan, and any gravity system that might be devised. The dam across Carquinez Straits would have many other advantages in addition to diverting the Sacramento waters into the lower San Joaquin River. During seasons of small stream flow, there is a ten- dency for the salt water of San Francisco Bay to work up into the network of channels that divide the rich delta lands at the mouth of the two rivers, into many islands. The dam below the mouth of these two rivers would prevent any damage to these fertile soils that might result from such occurences. Further, this dam would maintain Suisun Bay in fresh water and make it possible to profitably reclaim all the tidal flats along its margin, and bring unlimited quantities of fresh water to the manufacturing centers arising along the bay shore from Benicia and Port Costa easterly to Antioch. It would provide a low level crossing for railroads and highways whose traffic now crosses Carquinez Straits on ferries. By constructing locks of adequate dimensions, this barrier would offer no obstruction to navigation. It can be designed to afford ample water way for floods of the Sacramento and San Joa- quin rivers so that flood heights on the lower river will not be increased over those of the past. The practicability of locating and constructing such a dam below the mouth of the Sacramento and San Joaquin rivers, has been investi- gated as far as could be without exploration borings at the various possible sites for its location. It was concluded that a dam in this vicinity is feasible but that extended studies of all possible sites should be pursued before a selection is made. This dam would be of added value in creating a large fresh water reservoir in Suisun Bay and the delta regions that would have a stor- age capacity of 500,000 acre feet between the present levels of high and low tide. Supplies of fresh water might be pumped from here for consumption, after filtration, in the metropolitan areas of San Fran- cisco Bay, as well as for agricultural use to supplement the local sup- plies of the bay region. Thus water might be brought close into the bay region without cost of conduit from the distant sources. These investigations show that waters of the Trinity River and the three forks of the Eel River in the North Pacific Coast region, might be diverted into the Sacramento River drainage through tunnels under the Coast Range Mountains, not prohibitive in expense if their waters WATER RESOURCES OF CALIFORNIA. 49 are developed in large quantities. With these diversions effected, there would be plenty of water, in the Great Central A^alley drainage area, to supply all its future needs as well as the requirements for all purposes about the San Francisco Bay region. The diversion for agricultural use from Suisun Bay would be by a canal leading southward through Tgnacio Valley. The water would be elevated in successive lifts into the Livermore Valley. A pumping head of slightly more than four hundred feet would be necessary to lift the water into Livermore Valley and additional pumping would be required to distribute the water over all of its arable lands. A tunnel through the hills separating Livermore Valley from San Fran- cisco Bay would take this water into the Santa Clara Valley at an eleva- tion sufficiently high to permit gravity distribution to practically all lands of this valley not irrigable from the waters of local streams. The agricultural areas of the bay region to the north, would be irrigated from diversions from the Eel and Russian rivers. "Water would be carried in a gravity canal almost one hundred miles in length into the Sonoma and Napa valleys to supplement their local supplies. Several hundred thousand acres of agricultural lands within the Sacramento drainage area, are isolated from the main body of its lands by the Sierra Nevada Mountains. The Pit River, in the north- eastern corner of the state, drains part of a great plateau region to the east of the Sierra Nevadas on the edge of the Great Basin of North America, and cuts through these mountains for a distance of sixty miles in a deep rock gorge to .ioin the waters of the Sacramento River before they emerge into the Great Central Valley. The agricultural areas of the Pit River lie in several parcels along its upper reaches and vary in elevation from 3000 to 5000 feet above sea-level. The comprehensive plan provides for irrigating 263,300 acres of these areas by gravity diversions from the Pit River or its tributaries. Seventeen reser%'oirs of varying capacity will be required to equalize the stream flow for these diversions. PACIFIC COAST DRAINAGE BASINS— SAN FRANCISCO TO SANTA BARBARA CHANNEL. Comprised within five larger valleys and several smaller ones, 890,000 acres of tillable lands lie along the Pacific Coast between San Francisco Bay and Santa Barbara Channel. Of these 135,000 acres are under irrigation at the present time. The water supply in the streams tra- versing these valleys is enough to cover their agricultural lands to a depth of two feet in an averace year, but the flow is so flashy that with unlimited storage, only two-thirds of their waters could be suitably equalized for irrigation use. Nevertheless, three-fifths of the total area can be irrigated under the comprehensive plan. In this plan the waters would be diverted from the streams in each valley and carried to the lands in gravity canals. The costly tunnels through the mountainous regions separating these valleys largely prohibit the importation of any small surplus waters that may occur in adjacent regions, so that the agricultural lands of each valley would be largely irrigated by inde- pendent systems. 50 WATER RESOURCES OP CALIFORNIA. PACIFIC COAST DRAINAGE BASINS— SANTA BARBARA CHANNEL TO MEXICAN BORDER. Southward from Santa Barbara Channel skirting the coast and on the Pacific slope of the Southern California mountains, lie 2,300,000 acres of fertile soils. These lie in the valleys of streams draining into the Pacific Ocean that are less separated by mountains than the valleys northward from the Santa Barbara Channel and form an almost con- tinuous body of agricultural land. Although several large streams traverse portions of this area, the total waters are hardly sufficient to cover the arable lands to half a foot in depth in the average year. Their flow is erratic and would require much storage capacity for their com- plete development for irrigation use. Reservoir sites are few in number and dams expensive. However, it is found that the water supply can be perfected on a large part of the 759,000 acres now irrigated and perhaps 250,000 additional acres be brought under water. Under the comprehensive plan, surface reservoirs would be con- structed and largely used for the temporary detention of the waters in the streams that they might be released in a more or less uniform flow for spreading over gravel beds. Excepting in the southern areas of this region, there are coarse alluvial fills that have a large water-holding capacity and easily yield their contained waters to wells sunk into their depths. Waters spread on the gravel beds of these valley fills would be absorbed to join the subterranean waters of these basins. Severed from contact wdth the atmosphere, these waters would be held in storage in the porous substrata without loss by evaporation and would be available as needed through pumping from wells. By combining surface and underground storage in a coordinated plan, the maximum service will be attained from these waters, even a greater service than could be obtained from storage in surface reservoirs, for with complete develop- ment by surface storage, about one-third of all the water would be lost by evaporation. Without some surface storage, however, to partially equalize the flow, large volumes of flood water would rush off into the ocean too quickly for absorption by the gravels in the stream beds or diversion to artificial spreading grounds. The artificial spreading of water is being practiced with success in some of the basins by diverting the clear waters that follow the first turbid flood flows. These spreading operations can be much extended by the use of surface storage works to partially equalize the flood flows and the employment of additional spreading areas. These investigations have mapped the location of the absorptive basins in this territory and collected much data on the surface and underground waters. ^^' Considerable amounts of water spread on the surface of these basins in irrigation, are known to sink to join the ground waters and increase the available supply for other areas. The total quantity of water in this region is so limited, however, that there cannot be any great increase in the areas watered unless means are discovered of maturing crops with smaller applications of water than are now customary. It is possible as water increases in value, that much may be accomplished in reducing losses by evaporation while applying the waters to the soils but at greater expense than is justifiable at the present time. "'See Appendix "C" to this report, Bulletin No. 7, State Department of Public Works, for maps of absorptive areas and underground water contours. WATER RESOURCES OF CALIFORNIA. 51 GREAT BASIN DRAIN AGE— SOUTH OF LAKE TAHOE. More than 3,000,000 acres of excellent agricultural lands lie in the south half of the state eastward from the Sierra Nevada Mountains and the range extending southerly from Tehachapi Pass. These are situated in several parcels varying in elevation from below sea-level to 5000 feet or more above. The local waters are small in amount, for of all the waters collected by the mountains that separate these areas from the rest of the state, only ten per cent run off their easterly slopes. But a small part of the entire area could be irrigated if it were not for the Colorado River bringing waters from drainage areas outside the state to within reach of 939,000 acres of these lands in the extreme southeastern corner of the state. There are now 500,000 acres irrigated from the natural flow of the Colorado River in this region, but the area can be almost doubled by the construction of storage works for saving over flood waters. These Avaters would be diverted in the plan, by gravity canals, that serve the greatest possible area. The local streams in the northerly part of this region are much more productive than in the south. The adjacent agricultural lands are at elevations greater than 5000 feet. The comprehensive plan would carry most of these waters southerly in a canal two hundred and eighty miles long to areas 4000 feet or less in elevation. The waters of local streams are sufficient to irrigate 430,000 acres, and in all, 1,369,000 acres can be irrigated in these regions. GREAT BASIN DRAI NAGE— NORTH OF LAKE TAHOE, Eastward from the Sierra Nevada Mountains and northward from Lake Tahoe, there are 667,000 acres of tillable lands situated in moun- tain valleys and on the plateau region of northeastern California that drain easterly toward the Great Basin of North America. These vary from 4000 feet to 5000 feet or more in elevation and occur in parcels of many sizes. There are now 82,500 acres under irrigation in this region and the comprehensive plan would increase this area by 48,000 additional acres. Storage reservoirs would regulate the stream flow, and the diversions would generally be near the lands to be watered. Short gravity canals would lead the water to the regions of use. NORTH PACIFIC COAST DRAINAGE. About half of the agricultural areas of the Pacific Coast drainage lie adjacent to Mount Shasta on the northern and western sides. Situated at elevations of from 2o00 to 4000 feet, these lands would take their waters from adjacent streams, principally the Klamath or its tributaries, and convey them by gravity to the regions of use. The other arable lands of the Pacific Coast drainage basins lie in lower levels. Mostly less than 500 feet above the sea, these lands lie in the valleys or on the detrital flats along the lower reaches of the streams. Gravity conveyance of the waters requires one canal over seventy miles in length and two more than twenty miles long. In all 699,200 acres can be irrigated under the comprehensive plan. Only 87,300 acres are now served with water out of a total area of 786,000 acres of agricultural lands in this region. 52 WATER RESOURCES OF CALIFORNIA. CHAPTER VII. SETTLEMENT. The four millions of people within the confines of California in nineteen hundred and twenty-three markedly distinguish this state from the wild and uninhabited mountains, the unsettled valleys and vacant plains of one hundred year.s ago. Transfigured through years of toil, the state's lands are now of immense wealth and the source of a great income in foodstuffs and minerals, while in the cities and towns are a multitude of industries that enhance the value of the natural products. Each succeeding generation contributes to these accumu- lated works that transform the fruits of the valley soils and the min- erals and waters of the mountains into means of sustaining greater numbers of people in prosperity and contentment. But the value of these resources and the value of these works is contingent upon their service to people. Neither fertile soil, crop-maturing waters or irriga- tion and hydro-electric structures; nor harbors, railroads, or industrial centers disclose their intrinsic value or seethe with industry without man 's vitalizing energy : rather, they are lifeless encumbrances on wide- flung landscapes unless experiencing human exploitation. So, without man to animate and guide them, great works constructed for convert- ing the resources of the state into life-sustaining and comfort-giving commodities, neither increase its wealth nor add to the contentment of its inhabitants. Projects for transforming the immense potential wealth of the state's waters into food or into light and warmth, must then grow in size and capacity of output in consonance with the augumenting num- bers of people waiting to put their product into use, or those industrial structures, inanimate and without volition, will weather in the elements, and, through nonuse, will deteriorate to early decay before oppor- tunity of service arrives. Enterprises that are carriers of water for domestic and industrial purposes or those which are to distribute its tireless energy in electric current to population centers and rural communities, are readily designed in size to accommodate themselves to growing communities, and select without difficulty, small numbers of employees to operate the works under the direction of trained and skilled superintendents. However, this not so with systems for carrying the waters of the streams to the agricultural lands that these may produce to their full capacity. On these systems, the users of the w^ater are so intimately dependent upon the supply, their successes and failures are so wrapped up in the cost of the waters and excellence of service, that they are as workers in the larger enterprise of developing water for the land in order that it may produce irrigated crops, rather than as consumers of water furnished by the distribution system. The works, the dams, the canals and the distribution ditches are but part of a system for WATER RESOURCES OF CALIFORNIA. 53 increasing the productivity of the soil and until this soil produces with greater abundance, the water impounding and distributing works are of no service to the people. For these reasons, private enterprises, distributing water for agricultural use and selling it as a commodity, have been supplanted in irrigation development, by mutual companies, district organizations or by the governing political subdivision.^^' In no other way have the interests of constructors of the works and users of the water become sufficiently coordinated that success could be attained in the enterprise as a whole. There are now perhaps, a million or more acres^^^ in California, fertile enough, and with water at hand, but which are failing to produce adequately to pay for all the costs including improvements on the land. Much of this is in large holdings and in new districts that have recently been brought under irrigation and, although it will undoubtedly be closely settled and produce to capacity within a few years, at present these lands are lacking in numbers of tillers of the soil to respond to the propitious agricultural environment of this state. At the same time, while these vast areas are but partially productive, eager workers and potential farm owners, anxious to prove their worth, but without money to make a start; skilled university-trained agriculturalists, capable of directing agricultural effort and anxious to exercise their training and accumulated knowledge, are about us in numbers ample to people and intensively farm these million or more acres and many more besides, if provision were made for their occupying the land. It is generally estimated that a settler, in addition to being an experi- enced farmer, should have at least from two to five thousand dollars capital to make the start under existing conditions with reasonable expectancy of ultimate success ; the success so necessary for maintain- ing the credit of irrigation enterprises. This ready money is required to level the land, to build a house, a barn, fences; to purchase a plow and harrow, a mower, rake and seed; to procure a horse, and cow, as well as to plant the first crop and sustain the settler until the first harvest is sold. Two thousand to five thousand dollars, often the sav- ings of a life-time, is not possessed by a large number of people experi- enced in farming, and who are desirous of undertaking the intensive cultivation of an irrigated farm. These requirements so limit the number of prospective occupants for California's agricultural lands that the rate of settlement '-^^ on the great irrigation projects already constructed is not as rapid as might be desired. In order to enlarge the number of people who may become settlers by reducing the initial cash outlay required, provisions are being made by some colonization enter- prises, through which land may be purchased with small payments that extend over longer periods of time than have heretofore been granted. Although the million or more acres of land in California now failing to put its water supply to use represents a partially idle value in land and works of perhaps $200,000,000, the future is more concerned with ^In 1920, less than 10 per cent of the Irrigated area of the whole United States was served by commercial enterprises, U. S. Census Report. =U. S. Census Report states that there were 1,675,426 acres which were not irrigated in 1920 but which the works were capable of irrigating. (Some of this is probably land that never will be irrigated.) <^'U. S. Census, 1920, reports 533,981 acres of irrigated land available for settlement by owners' statements. The Real Instate Commissioner of California, after a canvass of the state, estimates that there are now 950,000 acres available for settlement of which 80 per cent is under irrigation. 54 WATER RESOURCES OF CALIFORNIA. increasing the rate of settlement than the present. The lands that are yet to receive irrigation waters are lands that have been left after the more easily developed projects have been completed, and the cost of water for them will be at an enhanced rate per acre over that which has prevailed in the past. These residual lands are equally fertile, but are usually situated more distant from the source of supply. Some are tracts more uneven of surface and so require eleborate systems of canals to carry the waters to the place of pouring out upon the soil. Others have to acquire water rights before a supply may be obtained, and all of them will have to construct storage works to hold over win- ter flood-waters for summer use and the run-off of wet seasons for times of drouth. The cost of these projects will be large in comparison with the ones undertaken in the beginning of irrigated agriculture when projects were small and the works simple. Future enterprises also must organize in increasingly large units, for there will be many more problems presented for solution than here- tofore, and these must be surmounted in order to consummate ulti- mate success. Practically all the summer flow of California's streams is now diverted for irrigation use and the lands which can be watered by constructing short canals have been put under irrigation ; but only one- quarter of the state's lands that need accessory moisture for greatest productivity can be watered by projects already constructed. Even now, huge combinations of hundreds of thousands of acres have been found necessary that lands situated remote from stream channels or source of supply may be improved. By building many miles of canals and huge reservoirs to augment the summer flow with saved-over flood waters from winter, these projects are preparing to carry water to the lands that, through intensive farming, they may be made to yield har- vests commensurate with the favorable climate and fertile soils of Cal- ifornia. The united eft'orts of whole communities is proving to be nec- essary to bring water to the needy lands which would otherwise remain dry and unproductive or whose yield would only be realized during seasons of copious rains. So that to bring water to the land, large projects with their immense construction programs are proving neces- sary even at this time, and their size and complication will grow with the future. The successful culmination of extensive and costl.y enterprises not alone necessitates that sound plans be adopted for the construction of the works, not alone that they may be erected in an efficient man- ner, not alone that they bring water to fertile soil at the time and in the quantity needed, but also that the land be quickly occupied by the large number of tillers of the soil, which irrigated agriculture demands to nurture and harvest the increased yield. The fruition of effort, the repayment of borrowed capital in interest and principal, and the production of wealth to the community involve thousands of oper- ators in these large enterprises, each farming from twenty to forty acres of irrigated lands. The running of the waters through the con- stracted ditches or even on to the plowed fields does not make the land produce. The yielding of harvests is just as necessary for the success- ful project as to secure adequate sums of borrowed money with which to build the works. The very essence of utility of these works is the interested and tireless efforts of the farm operators that strive with WATER RESOURCES OF CALIFORNIA. 55 and overcome the man}' annoyances incident to maturing crops on the land. But are there sufficient numbers of people possessing the experience and skill, the capital and desire, to animate these works and quickly bring the lands to fruitful harvests under the requirements of existent conditions of land sales and farm credits'; The holders of large proper- ties for several years past have been searching for them and many still believe that they may be found, but their only partly rewarded efforts are indicative that perhaps they are not to be immediately found in the numbers desired. As the years succeed themselves, the markets for California's farm products are ever widening. Kefrigerator cars, fast express trains, and the cold storage of ocean transport are carrying California's fruits and foods for display in markets undreamed of a few years ago, and the demand for these is increasing at an accelerated rate. With propitious climate and soils, this state is attaining ranking position, a precursor to all the states of the Union in value of agricultural and horticultural products yielded by their lands, and an analysis of the reports of the United States census indicates that there will be a market for Cali- fornia's products in 1940, but seventeen years hence, three-fold greater than in the year 1920. The multiplying population of this state also demands food in greater and even greater amounts, for the state is growing fast. During the decade that closed with 1920, California experienced an enlargement in the numbers of people inhabiting its farms and cities, of forty-four per cent of the aggregate of 1910. These investigations show that there is land and water ample for production commensurate with this enlarging demand for California's agricultural products, and the past success in financing irrigation con- struction demonstrates that money will be at hand to erect the works and fashion the canals, but the greatest success can only be attained through effecting a system of colonizing the land that will iasten the influx of settlers and secure a multiplicity of tillers of the soil without dela}-^, so that long periods of stagnation between their construction and time of use may not bring embarrassment to the enterprises. The large units in which future development must be organized will make it increasingly desirable to accelerate the rate of rural settlement of this state. Two examples of well coordinated and systematized colonization may be seen at Durham in Butte County, and at Delhi in Merced County, the two state land settlement projects.^^^ However, these two colonies are but a demonstration of possibilities in stimulating rural settlement for their combined area is only 13,920 acres. A statewide stimulus to the occupancy of farm lands would greatly increase the naturally expeditious growth of California's irrigated communities, insure a full measure of production to meet all demands, and assist California in seizing and holding agricultural and horticultural supremacy among the states of this nation. <»For description of these projects see "Report of Division of Land Settlement," a subdivision of tlie Department of Public "Works of the State of California, the report being Part V of the first biennial report of that department, dated Septeabfir 1, 1922. 25712 4-23 15M THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW OCT 18 . 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