GEOLOGICAL SURVEY CIRCULAR 378
WATER RESOURCES OF THE SAN FRANCISCO BAY AREA, CALIFORNIA
UNITED STATES DEPARTMENT OF THE INTERIOR Fred A. Seaton, Secretary
GEOLOGICAL SURVEY Thomas B. Nolan, Director
GEOLOGICAL SURVEY CIRCULAR 378
WATER RESOURCES OF THE SAN FRANCISCO BAY AREA, CALIFORNIA
By H. F. Matthai, William Back, R. P. Orth, and Robert Brennan
Washington, D. C. 1957
Free on application to the Geological Survey, Washington 25, D. C. PREFACE
This report is one of a series concerning the water Upson (in preparation), and Thomasson, Olmsted, and resources of selected industrial areas of national im Leroux (in preparation) were used extensively in writing portance, and has been prepared at the request of and the sections on ground water and geology for the areas in consultation with the Water and Sewerage Industry north of the bays. and Utilities Division of the Business and Defense Services Administration of the Department of Com Many persons and organizations contributed inform merce. This series is designed to provide information ation used in this report. Special acknowledgment is for national defense planning and at the same time to due the State Division of Water Resources of the render valuable service to business and industry in Department of Public vVorks and the State Water Re their development of water resources for present and sources Board. The sections on ground water and geol future use. These reports are prepared under the di ogy of the Alameda plain and Livermore Valley were rection of J. B. Graham and K. A. MacKichan. The written with information furnished by A. J. Dolcini and present report was prepared by H. F. Matthai, hydrau R. T. Bean, of California Division of Water Resources. lic engineer, under the supervision of H. M. Stafford, The report on geology and water resources of Santa engineer-in-charge, Sacramento, Calif., and R. C. Clara Valley, in preparation, under the direction of Briggs, district engineer (Surface Water Branch); by J. M. Haley and T. P. Wootton, was used for the Santa William Back, geologist, under the supervision of Clara Valley section of this report. The authors also F. H. Olmsted and J. F. Poland, district geologists wish to acknowledge the courtsey and cooperation of the (Ground Water Branch); and by R. P. Orth and Robert following agencies: San Francisco Water Department, Brennan, chemists, under the supervision of I. W. San Francisco Public Utilities Commission, East Bay Walling, district chemist of the Quality of Water Branch. Municipal Utility District, Santa Clara Valley Water Much of the data summarized here has been collected Conservation District, California Water Service during many years by the y. S. Geological Survey, in co Company, City of Vallejo, Marin Municipal Water Dis operation with Federal, State, and local agencies, or has trict, counties of Santa Clara, Alameda, Contra Costa, been furnished by the California Division of Water Re Napa, and Sonoma, the U. S. Weather Bureau, and the sources. The reports by Cardwell (1955), Kunkel and U. S. Bureau of Reclamation.
II CONTENTS
Page Page Abstract...... 1 Water supply of subareas Continued Introduction...... 2 Alameda County Continued Location and extent...... 2 Surface Water...... 27 Topography...... 2 Alameda Creek...... 27 Importance of area ...... 2 Discharge ...... 27 Population...... 2 Quality...... 27 Industry...... 2 San Lorenzo Creek ...... 29 Mineral resources...... 2 Discharge ...... 29 Climate ...... 2 Quality...... 29 Occurrence of water ...... 4 San Leandro Creek...... 29 Ground water ...... 6 Western Contra Costa County...... 29 Primary aquifer...... 6 Ground water ...... 30 Secondary aquifer ...... 6 Surface water...... 30 Essentially non-water-bearing rocks ...... 8 Walnut Creek ...... 30 Fluctuation of water levels ...... 8 Discharge ...... 30 Recharge...... 8 Quality...... 30 Natural recharge ...... 8 San Pablo Creek...... 30 Artificial recharge ...... 8 Pinole Creek...... 31 Discharge ...... 10 Suisun-Fairfield area...... 31 Overdraft...... 11 Ground water...... 31 Ground-water storage capacity...... 11 Yield and depth of wells ...... 31 Surface water...... 11 Water-level fluctuations...... 31 San Francisco Bay system...... 11 Pumpage ...... 31 Records of streamflow...... 11 Quality...... 31 Floods...... 12 Surface water...... 31 Significance of the chemical and physical Napa Valley...... 32 characteristics of water...... 13 Ground water ...... 32 Water supply of subareas...... 14 Yield and depth of wells...... 32 San Mateo County...... 14 Water-level fluctuations...... 32 Surface water...... 14 Pumpage ...... 32 Discharge ...... 14 Quality...... 33 Quality...... 14 Surface water...... 33 Santa Clara Valley...... 20 Napa River ...... 33 Ground water ...... 20 Discharge ...... 33 Yield and depth of wells ...... 20 Quality...... 33 Water-level fluctuation ...... 20 Sonoma Valley ...... 33 Pumpage ...... 20 Ground water...... 35 Salt-water encroachment...... 20 Water-level fluctuations...... 35 Land-surface subsidence...... 20 Yield and depth of wells ...... 35 Quality...... 20 Pumpage ...... 35 Surface Water...... 24 Quality...... 35 Guadalupe River...... 24 Surface water...... 36 Discharge ...... 24 Petaluma Valley...... 36 Quality...... 24 Ground water...... 36 Coyote Creek ...... 24 Yield and depth of wells ...... 36 Discharge ...... 24 Water-level fluctuations...... 36 Quality ...... 24 Pumpage ...... 36 Other streams ...... 24 Quality...... 37 Artificial recharge ...... 24 Surface water...... 37 Alameda County...... 25 Petaluma Creek...... '...... 37 Ground Water...... 25 Discharge ...... 37 Livermore Valley ...... 25 Quality...... 37 Yield and depth of wells ...... 25 Novato Creek ...... 37 Water-level fluctuations...... 25 Discharge ...... 37 Pumpage ...... 25 Quality...... 39 Quality...... 26 Southern Marin County( ...... 39 Sunol and Castro Valleys ...... 26 Surface water...... 39 Alameda Plain ...... 26 Corte Madera Creek ...... 39 Water-level fluctuations...... 26 Arroyo Nicasio...... 39 Pumpage ...... 26 Imported water...... 39 Quality...... 27 Hetch Hetchy system...... 39 III CONTENTS
Page Page Imported water Continued Water use...... 49 Mokelumne system...... 40 Urban use...... 49 Contra Costa Canal ...... 40 Industrial use ...... 50 Cache Slough System ...... 41 Irrigation...... 51 Public water supply systems ...... 41 Surface water ...... 51 San Francisco Water Department...... 42 Ground water...... 51 San Jose Water Works...... 42 Changes in water East Bay Municipal Utility District ...... 45 quality with use...... 51 Cities of Pittsburg and Martinez and Potentialities...... 51 California Water Service Co...... 47 Local supplies...... 52 Vallejo Water Supply System...... 47 Imported supplies...... 52 Napa Water Department ...... 48 Water laws...... 53 North Marin County Water District ...... 48 Selected bibliography...... 54 Marin Municipal Water District ...... 48
ILLUSTRATIONS
[All plates in pocket]
Plats 1. Map of the San Francisco Bay Area showing availability of ground water, and generalized water levels. 2. Map of San Francisco Bay Area, showing stream-gaging sites. 3. Present and ultimate water service areas in the San Francisco Bay Area. 4. Relation between streamflow and the chemical and physical characteristics of the water. 5. Service areas and importation work of principal public water supply systems. Page Figure 1. Geographical distribution of precipitation ...... 3 2. Precipitation in the San Francisco Area, 1849-1953...... 4 3. Average, maximum, and minimum monthly precipitation at San Francisco, 1849-1953...... 5 4. Average, maximum, and minimum air temperature at San Francisco and Livermore ...... 6 5. Hydrographs of selected wells south of the bays and accumulated departure from average precipitation at San Francisco ...... 9 6. Hydrographs of selected wells north of the bays...... 10 7. Duration of published streamflow records in the San Francisco Bay Area...... 12 8. Maximum and minimum concentration of chemical constituents in selected streams in the San Francisco Bay Area...... 14 9. Duration curves of daily flow, Pescadero Creek near Pescadero and San Lorenzo Creek at Hayward ...... 15 10. Generalized geologic cross-sections of ground-water basins ...... 21 11. Duration curves of daily flow, Alameda Creek near Niles ...... ,_.^r\ ...... 28 12. Draft-storage curve, Alameda Creek near Niles ...... 29 13. Frequency of floods, Alameda Creek near Niles, water years 1926 53 ...... 29 14. Duration curves of daily flow, Napa River near St. Helena...... 34 15. Draft-storage curve, Napa River near St. Helena...... '35 16. Frequency of floods, Napa River near St. Helena, 1930-32, 1940-53 ...... 35 17. Duration curves of daily flow, Petaluma, Novato, and Corte Madera Creeks...... 38 18. Water importation, water years 1929-53...... 39 19. Hardness of water delivered to consumers, San Francisco Water Department...... 44 20. Urban use of water, San Francisco Bay Area, 1950 ...... 49
TABLES
Page Table 1. Stratigraphic units within ground-water basins and their water-bearing characteristics ...... 7 2. Ground-water pumpage in acre-feet ...... n 3. Estimated gross ground-water storage capacity...... n 4. Discharge of San Francisquito, Matadero, and Stevens Creeks ...... 15 5. Selected analyses of surface waters in the San Francisco Bay Area ...... 16 6. Selected chemical quality data for ground waters in the San Francisco Bay arga...... 22 7. Maximum, minimum, average, and median monthly and annual discharge of Alameda Creek near Niles, in mgd, water years 1925 53 ...... 27 8. Maximum, minimum, and average monthly and annual discharge of San Lorenzo Creek at Hayward.... 29 9. Maximum, minimum, and average flow of streams in Walnut Creek basin, water year 1953 ...... 30 10. Estimated ground-water pumpage in Napa Valley, in acre-feet ...... 32 11. Maximum, minimum, average, and median monthly and annual discharge of Napa River near St. Helena, in mgd, water years 1931-32 and 1941-53...... 33 IV TABLES
Page Table 12. Maximum, minimum, and average monthly and annual discharge of Petaluma Creek near Petaluma, in mgd, water years 1949 53...... 37 13. Maximum, minimum, and average monthly and annual discharge of Novato Creek near Novato, in mgd, water years 1947 53...... 37 14. Chemical quality of Contra Costa Canal water...... 40 15. Public water-supply systems in the San Francisco Bay Area, 1953 ...... 41 16. Chemical analyses of San Francisco Water Department water...... 43 17. Ranges in chemical constituents in water served to consumers, San Francisco Water Department, July 1, 1949, to June 30, 1953 ...... 44 18. Chemical analyses of composite water samples, San Jose Water Works, 1946 53...... 45 19. Chemical analyses of treated waters from principal sources, East Bay Municipal Utility District, 1950-53 ...... 46 20. Range in monthly chemical and physical characteristics of treated water, East Bay Municipal Utility District, 1953 ...... 47 21. Chemical analyses and turbidity measurements of water from Vallejo Water Supply System...... 47 22. Chemical analyses and related physical measurements of water from Vallejo Water Supply System...... 48 23. Physical quality and pH .of raw and treated waters, Marin Municipal Water District, July 1951 to June 1952...... 49 24. Water demands by industry, San Francisco Bay Area, 1948 50...... 50 25. Present demands and safe yields of public water supply systems ...... 51
WATER RESOURCES OF THE SAN FRANCISCO BAY AREA, CALIFORNIA
By H. F. Matthai, William Back, R. P. Orth, and Robert Brennan
ABSTRACT demand for water in the San Francisco Bay Area is about 710, 000 acre-feet, or 630 mgd. About 42 percent, The sources of water in the San Francisco Bay Area or 300,000 acre-feet is used to meet agricultural re are the streams and ground-water basins within the quirements; about 53 percent or 380,000 acre-feet is area and importations from streams of the Sacramento used for urban requirements, and 5 percent is needed and San Joaquin River basins. Since 1895, annual natural for other requirements. This total demand is met from runoff in the area has averaged about 1,250,000 acre-feet developments of both local and imported waters which and ranged from 90, 000 to 3,100,000 acre-feet. In gen at present (1954) are capable of supplying a little more eral, the chemical quality of the water in the streams than 1,000,000 acre-feet annually. Present local in is suitable for most domestic, industrial, and irriga stallations, developing surface- and ground-water sup tion uses. The water is mainly a calcium bicarbonate plies, have a yield of about 480,000 acre-feet. type with low to moderate concentrations of dissolved solids. In places it is high in calcium and magnesium Of the 380,000 acre-feet required for urban use, hardness. 50 percent is for domestic use, 37 percent is for in dustrial use, 8 percent is for commercial use, and There are eight major ground-water basins in the 5 percent is for other uses (parks, institutions, etc.). area. Although local overdraft exists in the four basins In terms of gallons per capita per day, domestic use is north of the bays, this is not a serious problem at about 66, industrial use 49, commercial use 10,. and present. In the basins south of the bays, varying con other uses 7. Data for the city of San Francisco show ditions of overdraft and resulting encroachment of saline that 47 percent of the water is for domestic uses and water from the Bay have occurred in Santa Clara 53 percent is for industrial and commercial uses. For Valley, the Alameda alluvial plain, and the Pittsburg the East Bay Municipal- Utility District the data show plain. Currently an overdraft exists in Livermore that domestic use accounts for 68 percent, and indus Valley. Although in some places ground water is of trial and commercial uses account for 32 percent of poor quality (saline-encroachment and high concentra the total. tions of boron), they are mostly of the calcium bicar bonate type and are generally suitable for domestic, Of the 300,000 acre-feet used to meet the require industrial, and irrigation use. ments on about 163,000 acres of irrigated lands, nearly all is supplied by ground water. The remaining minor As the San Francisco Bay Area itself is an area of part is supplied by the direct diversion of surface-water deficient water supply, water is imported from the sources. About 70,000 acre-feet of the water applied Tuolumne River basin (Hetch Hetchy system) for the in irrigation is returned to ground-water storage. San Francisco Metropolitan area, from the Mokelumne River basin for the East Bay Municipal Utility District, Surface-water sources in the San Francisco Bay Area from the Sacramento-San Joaquin Delta via Contra have been largely developed, and only a few small ad Costa Canal for the Contra Costa County area, and ditional local supplies are economically feasible. The from Cache Slough, tributary to the Delta, for the city ground-water basins cannot support large additional of Vallejo. The annual total of these importations withdrawals. Increased future requirements of the area (232,000 acre-feet in the 1953 water year) is currently must, therefore, be met by importations. For the im about 48 percent of the average annual yield of developed mediate future, the increased demands of the principal local surface- and ground-water supplies. The import public water systems can be satisfied to the extent from the Tuolumne and Mokelumne River basins is that the present capability or safe yield of the systems typical mountain water that is soft, low in dissolved exceeds the current demand. The aggregate safe yield solids, and is of the calcium and magnesium bicarbon of the six largest systems exceeded the 1953 demand ate type. Water from the Sacramento-San Joaquin Delta by about 392, 000 acre-feet. Compared to the present is a mixture of Sacramento River water of good quality water requirements in the area of 710,000 acre-feet, and San Joaquin River water of poorer quality. the California Division of Water Resources has esti mated that the total use under ultimate development with The area of urban and agricultural use of water totals 85 percent urbanization will be between 3,000,000 and about 439, 000 acres or 17 percent of the land in the San 3,400,000 acre-feet annually, depending on whether or Francisco Bay Area. An additional area of 272,000 acres not the tidelands are reclaimed. is devoted to agriculture but is not irrigated. Many plans or proposals for the importation of addi On the basis of studies made by the California Divi tional water have been made. Plans of the city of San sion of Water Resources in 1949, the annual gross Francisco call for an expanded Hetch Hetchy system 1 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA plus present local sources to give a combined yield of bay part of the area, although it had the greatest per about 500, 000 acre-feet annually, or more than three centage increase in the last 10 years. times the 1950 demand. Planned development of the Mokelumne River system by East Bay Municipal Utility District would yield a total of 364,000 acre-feet annual Industry ly, or more than three times the 1950 demand, In the delivery of 33,000 acre-feet in 1953, only 17 percent The key to the Bay Area's industrial development has of the ultimate planned capacity of the Contra Costa been the geographic setting coupled with excellent trans Canal was used. As one feature of the proposed Feather portation facilities. A transportation network, including River Project of the California Water Plan, water would transcontinental rail and highway facilities, air trans be diverted from the Sacramento-San Joaquin Delta to port services, and steamship lines, converge in San Livermore Valley, southern Alameda County, and Santa Francisco. Clara Valley; present plans contemplate an annual de livery of 127, 000 acre-feet to the Alameda-Santa Clara The manufacturing groups in order of importance are area. Other proposals under study include diversions food and related products, chemicals, transportation from coastal streams into the northern part of the San equipment, printing and publishing, fabricated metal Francisco Bay Area, and construction of salt-water products, machinery, primary metal industries, petro barriers across the bays. leum products, textile mills and apparel, stone, clay and glass products, and paper and related products. Along the south shore of Suisun and San Pablo Bays the INTRODUCTION most important industries are the oil, chemical, and paper industries. Along the southern shore of San The purpose of this report is to summarize the avail Francisco Bay the important industry is salt production able data on surface and underground waters for the by solar evaporation. In the north bay area, the ma'jor San Francisco Bay Area and to present the information employers are the military installations at Hamilton in a form suitable for use in the preliminary planning Air Force Base, Mare Island Naval Shipyard, Benicia for location and expansion of industrial facilities. No Arsenal, and Travis Air Force Base. Parks Air Force attempt has been made to present a complete record of Base and an Atomic Energy Commission plant are in the hydrology of the area. Livermore Valley.
The agriculture enterprises of the area fall into two Location and Extent general groups, one supplying fresh fruit, vegetables, flowers, poultry and dairy products to the metropolitan The San Francisco Bay Area discussed in this report area, and the other producing fruit, grain, wine, and comprises all basins draining into San Francisco, San cattle for use throughout the State and Nation. Pablo, and Suisun Bays westward from the confluence of Sacramento and San Joaquin Rivers; and all basins draining into the Pacific Ocean south of Tomales Point Mineral Resources and north of Pescadero Point. (See pi. 1.) The Area extends about 120 miles along the coast and averages Although mining is of little importance, several min nearly 45 miles in width. It occupies an area of about erals of commercial value are found in the area. Mer 4, 400 square miles, and includes either all or a major cury ore is mined in four of the counties, and small part of the following nine counties: Mar in, Sonoma, quantities of silver and gold are obtained within the area. Napa, Solano, Contra Costa, Alameda, Santa Clara, Stone, rock, sand, gravel, and materials for brick and San Mateo, and San Francisco. tile are plentiful and widely distributed. Lime and materials for cement are quarried in the area. Table salt, magnesium salt, and bromine are produced in Topography large quantities.
The San Francisco Bay Area lies completely within the Coast Ranges geomorphic province of California. Climate The Coast Ranges form a nearly continuous barrier between the Pacific Ocean and the Great Central Valley The climate of the San Francisco Bay Area is marked from Santa Barbara County on the south to Humboldt by wide contrasts within short distances. The Pacific County on the north, almost two-thirds of the length of Ocean and the topography are the two major features California. The only break in this barrier is in the Bay influencing the climate; the effects being most noticeable Area where a broad irregular gap in the mountains, in a general west-east direction. The isohyetal map now flooded by the waters of the three bays, affords an (the lines connect points of equal precipitation) of the outlet for the drainage from the Sacramento and San area (fig. 1) clearly shows the.effect of the mountains Joaquin Valleys. upon precipitation and the wide range in the average an nual precipitation in various sections of the area. Dis tinct wet and dry seasons are typical of the region along Importance of Area the west coast of the United States. (See figure 2.) Precipitation data are reported for the year ending Population June 30, so that each wet season is then complete with in the year under consideration. According to records The population of the San Francisco Bay Area was collected by the U. S. Weather Bureau, the average 2, 560, 000 in 1950, an increase of 55 percent since 1940. (July 1 to June 30) precipitation at San Francisco for The present (1954) population is estimated at 3,000,000. the period 1849 to 1953 is 21.99 inches. The annual Only about 10 percent of the population is in the north precipitation and cumulative departure from average INTRODUCTION
EXPLANATION
Line of equal precipitation, in inches
Boundary, San Francisco Bay Are
Contour interval 500 feet
Figure 1. Geographical distribution of precipitation. !^/l#nts3' 'hW WATER RESOURCES OF THE SAN FRANCISCO BAY AREA are moderated by the Pacific Ocean. During June, July,
100
LU 60
40
20L CUMULATIVE DEPARTURE FROM AVERAGE PRECIPITATION AT SAN FRANCISCO (AVERAGE AT SAN FRANCISCO 21.99 IN..)
ANNUAL PRECIPITATION AT SAN FRANCISCO 130
120
A I A f 110 A\\ I s
100
90
80
70
Data from U. S. Weather Bureau based on PROGRESSIVE 10-YEAR MEAN PRECIPITATION climatic year July 1 June 30
Figure 3. Average, maximum, and minimum monthly precipitation at San Francisco, 1849-1953. WATER RESOURCES OF THE SAN FRANCISCO BAY AREA importance or"Primary aquifer" and aquifer of sec ondary importance or "secondary aquifer. "
The rocks of the area can be divided into three groups, the primary aquifer, secondary aquifer, and essentially non-water-bearing rocks. (See plate 1.) The geologic formations that are included in these three groups are listed and described briefly in table 1.
Primary Aquifer
The aquifer of primary importance in the San Fran cisco Bay Area is composed of the alluvial deposits of sand, gravel, and clay. The formations that these sediments comprise are the Recent alluvium, older alluvium of late Pleistocene age, and terrace deposits of Pleistocene age. This Recent and late Pleistocene alluvium underlies the valley floors of the ground-water basins. (See pi. 1.) The lithology and thickness for the alluvium in each ground-water area are given in table 1.
'These alluvial sediments attain their greatest thick ness in Santa Clara Valley, where the maximum thick ness is about 1,000 feet. The yields of wells are also greatest in Santa Clara Valley, ranging up to about 2, 000 gallons per minute.
Secondary Aquifer
The formations that compose the aquifer of second ary importance in the Bay Area consist of many rock types (table 1). In general this group consists primarily of Pliocene volcanic rocks and Pliocene or Pleistocene San Francisco, 1875-1953 Livermore, 1871-1950 continental sediments of sand, gravel, and clay. Within each ground-water basin these rocks underlie the pri Figure 4. Average, maximum, and minimum air tem mary aquifer, and form a'discontinuous border around perature at San Francisco and Livermore. the basin between the valley floor and the foothills (Pl. 1). Ground Water North of the bays, the rocks that compose the sec Ground water is the water that occurs below land ondary aquifer are the Sonoma volcanics, the Merced, surface in the zone where all open spaces within the Petaluma, Huichica, Glen Ellen formations, and locally rocks are filled with water. The openings range in thin veneers of alluvium. size from extremely minute spaces between clay par ticles, to larger openings in sand and gravel, and open The Sonoma volcanics form a major part of the sec ings caused by fracturing and solution channels in con ondary aquifer north of the bays, ana border Sonoma solidated rocks. Rocks that have large interconnected Valley on both the east and the west. A few isolated openings will transmit more water than rocks with patches occur west of Petaluma Valley. small or poorly connected openings. Napa Valley is almost entirely enclosed by these Ground water occurs either under confined or uncon- volcanic rocks with a narrow band extending nearly the fined conditions. Under unconfined or "water-table full length of the Valley on the west side and enclosing conditions" the top of the zone of saturation is in per the north end. On the east an outcrop about 6 miles meable material. Under confined or "artesian condi wide forms the valley boundary and extends eastward tions" the upper part of the zone of saturation is com to crop out in northwestern Suisun Valley. posed of a layer of material that is considerably less permeable than the underlying material. In the San The principal water-bearing rocks in the Sonoma vol- Francisco Bay Area every major ground-water basin canics"are the unweathered tuffs and pumices. Wells contains water under both confined and unconfined can obtain small to moderate yields everywhere that conditions. these rocks are saturated for a reasonable thickness.
An aquifer is a formation, part of a formation, or a The Merced formation crops out in Petaluma Valley group of formations, in which connected openings are on the northwest edge and along the southeast border. large enough to allow water to be withdrawn by a well. Wells that penetrate only the Merced formation in the In this report "aquifer" is used in its broadest sense rolling upland area, where the formation is thin, pro and refers to a group of formations. As such, only duce low yields. However, wells in Petaluma Valley two aquifers are discussed, the aquifer of primary that penetrate the Merced formation where it is thickest OCCURRENCE OF WATER
th'l I'M!.§
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I 1
T> X S °.«'S" a « .iijl . S^ °- =a S35 n .|,-3«l I*|f8 -a -a 1 *j? Itl^ls^^Hf^^Bi §llll« 00^ O * w « ujUBOS'u q'oJg'fi"J I «M 3 i ^ali S J n .5 < ww iLSi! -io S S S..S I 3 I ° rH S ]1 4. 3 > Ill- '°rs M ' -H"^ « QNV AHVIXHEL H3CTIO ONV AHVU.H3J. WATER RESOURCES OF THE SAN FRANCISCO BAY AREA and overlain by alluvium, have yields ranging up to water levels are highest in the spring and lowest in late 650 gpm, the highest of any wells in the valley. summer and autumn. Water-level fluctuations may be considered in their short-term or long-term effects. The Petaluma formation crops out along the north Short-term fluctuations indicate the change of required west side of upper Petaluma Valley, and wells in this pumping lift of ground-water from day to day or season formation yield moderate quantities of water in areas to season. The long-term fluctuations showing the where sand forms the major portion of the section. change year after year are most significant in estimat About 1935 the highest reported yield was 350 gpm. In ing future ground-water development. Plotted on 1950 most wells that penetrated only the Petaluma figure 5 are hydrographs of five wells south of the bays. formation yielded less than 50 gpm. Figure 6 shows the hydrographs for five wells north of the bays. The largest outcrop of the Huichica formation in this area is at the south end of the range of hills that sep All the hydrographs for the wells south of the bays arates Sonoma and Napa Valleys. The Huichica also have nearly the same long-term fluctuations. The hy crops out in the low hills east of Napa Valley. Wells drographs have the same general shape as the graph of drilled into the upper part of the Huichica formation rainfall at San Francisco plotted as cumulative departure produce very low yields, at some places not enough for from the average for the period 1849 1953. domestic needs. Wells drilled into the lower Huichica are slightly more productive but generally yield less Although the rainfall was about normal for the 4 years than 20 gpm. 1942 46, the water levels of wells in the Santa Clara Valley and the Alameda plain declined during this period Within the Bay Area the Glen Ellen formation crops due to increased pumpage. out only along the west side of Sonoma Valley. The Glen Ellen underlies the alluvium, and is in contact with the Huichica formation beneath the alluvial plain. Recharge This formation does not yield water freely to wells, and most wells yield less than 10 gpm. Recharge is the addition of water to the ground-water reservoir, and can take place in several natural or South of the bays the secondary aquifer consists artificial ways. Natural recharge is that portion of the primarily of the Santa Clara formation and the Liver- replenishment that is not a result of activities of man. more gravel of Clark (1930). This aquifer also in Artificial recharge is accomplished in the Bay Area by cludes terrace deposits along the south shore of Suisun infiltration of imported surface water and the construc Bay and on the ocean side of San Francisco Peninsula, tion of dams and canals specifically for the purpose of Pleistocene deposits in the Oakland area, the Merced inducing percolation into the ground-water reservoir. formation on San Francisco Peninsula, sand dunes in Salt-water encroachment is an undersirable type of San Francisco County, and locally thin veneers of al recharge that may occur in basins adjacent to saltwater luvium. when ground-water levels are drawn down below sea level as a result of excessive pumping draft. The Santa Clara formation crops out in a narrow dis connected band in the hills adjacent to Santa Clara Valley, extends northward along the Alameda plain, Natural recharge and beneath the Recent alluvium of the valley floor. This formation consists of up to 4, 000 feet of continen Under natural conditions the ground-water bodies in tal sand, gravel, silt and clay; and it supplies water to the Bay Area are recharged (1) by direct infiltration of deep wells around the outer margins of the valley, and precipitation on the valley floors, (2) by subsurface in to small wells in the hills bordering the valley. flow of water that falls as precipitation in the mountain and hill areas, and (3) by percolation of surface water The Livermore gravel forms a wide outcrop along in the permeable reaches of the streams. All fresh the southern part of Livermore Valley. This formation water for natural recharge of ground-water basins of is very similar to the Santa Clara formation-in lithol- the Bay Area originates as precipitation within the area. ogy and thickness. The Sacramento and San Joaquin Rivers are the only sources of fresh water that flow into the San Francisco Bay Area. Prior to the importation of water from the Essentially Non-Water-Bearing Rocks Sacramento-San Joaquin Delta, the imported water did not recharge the ground-water basi is along the Bay shore. Essentially non-water-bearing rocks, composed mainly of sandstone, shale, metamorphic and igneous rocks, are the oldest in the area and range in age from Artifical recharge lower Paleozoic or Precambrian to generally about middle Pliocene. (See table 1.) These consolidated Artifical recharge of fresh water can occur as (1) a rocks comprise the mountains and hill lands, underlie result of deliberate efforts to increase the ground-water the aquifers in the valleys and occupy most of the area. reserves or (2) an additional, or secondary, benefit (See plate 1.) These rocks contain some water along from certain water-use practices. joints and other fractures and,at a few locations, wells have been developed from the water in these openings. Artificial recharge is common as an additional bene fit of certain water-use practices in every ground-water basin within the Bay Area. These practices include Fluctuation of Water Levels excessive application for irrigation of imported water In the San Francisco Bay Area, where nearly all or local surface water, disposal of sewage effluent in precipitation occurs between October and May, the leaching fields, and disposal of water used for cooling. OCCURRENCE OF WATER \ t / t \ / I t / 0 » V | lit S itgi ? / 1_ r , E >§- i/ 0° / \ ( \ / / / { / 1 ( \ \ I S 8 . 8 R 8 8 j|| 8 S3HONI N lunim d3Q 3AI1Virwino 133J Nl 13AD U31VM JO JOniUTV 133J Nl 13A31 M31VM JO 3QniU.1V 10 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA 175 1 i 1 1 1 t Napa Valley Land surface ^^^^^"""^^^ ; ^^^****^^ r^^ 1 150 JJ"W-l_ 1 "^ ^v^,^ ^"^^ ^^~ Well 7N/5W-16B1 MX 125 i 1 1 , 1 1 - r ' ou 1 1 i i Lar id surface Napa Valley *rii/*rvv ^«j^^ ^ v^^. 25 L L and surface Sonoma Valley 5N/5W-28N1 s's\ H Sea level yy*^^s. , ^ u_LU ;' ^^k^-x Petaluma Valley"" / \ / z 1 N\rV/ 5N/7W-35K1 \v~ _i LU V Lu 25 _i ^ ^T cc LU 1 fc 50 i I i i i i 50 Land surface 25 Sea level Suisun-Fairfield 5N/2W-29R1 / 25 50 75 1949 1950 1951 1952 1953 1954 Figure 6. Hydrographs of selected wells north of the bays. Santa Clara Valley is the only place within the Bay springs, seeps, and effluent streams, and by evapora Area where conservation works have been constructed tion and transpiration. for recharging of ground-water bodies. Artificial discharge is by pumping from wells. Table 2 shows the pumpage for the major basins for Discharge which records are available. Discharge of water from the ground-water body can Although, this table does not include all the ground- take place in several ways. Natural discharge is from water pumpage in the Bay Area, it is a large part of OCCURRENCE OF WATER 11 Table 2. Ground-water pumpage in acre-feet in San Francisco Bay Area. Ground-water basin Year Irrigation Domestic Industrial Urban Other Total Oct. 1948 to Sept. 1949 a!97, 500 31,800 2,300 231,600 Oct. 1948 to Sept. 1949 38, 700 8, 300 46,700 Oct. 1949 to Sept. 1950 22,200 6, 500 28,700 Apr. 1949 to Mar. 1950 b7, 900 Apr. 1949 to Mar. 1950 3,000 1,000 130 730 700 5,560 Apr. 1949 to Mar. 1950 1,900 500 2,400 Petaluma Valley...... Jan. 1949 to Dec. 1949 250 720 120 760 1,850 a Applied water; acres irrigated times amount of water used per acre. D Data not available for breakdown of total. the total. About four-fifths of the ground water pumped tained within specified depth zones of each basin. The is for irrigation. More than two-thirds of all ground- gross storage capacity is many times greater than the water pumpage in the Bay Area is in Santa Clara Val present annual pumpage. In times of emergency or ley. drought these basins could produce much larger a- mounts of water, for a short period of time, than they Overdraft now do. A large basin can be pumped at a rate ex ceeding the safe yield for a longer period of time than A ground-water basin is overdrawn when the with can a small basin. However, these gross storage drawal rate is too great to be maintained perennially supplies should be considered only a temporary source and lowers the water level below the economic pump of water, because in many of these basins the present ing lift, or causes impairment of the water quality in pumpage already exceeds the perennial or safe yield, the basin. A secondary problem developed by over which in general is the average recharge available to draft is land-surface subsidence, whereby the land the basin. surface lowers due to compaction of clay and silt layers as a result of a decline in hydrostatic pressure. The total annual natural and artificial discharge cannot ex Surface Water ceed the annual replenishment for long periods without creating an overdraft. San Francisco Bay System The dominating surface-water feature in the San Ground-Water Storage Capacity Francisco Bay Area is the San Francisco Bay system. The water of the bays in the San Francisco Bay Area The ground-water storage capacity of a specified is essentially ocean water. This highly concentrated volume of deposits in a ground-water basin is the a- saline water is not suitable for municipal, irrigational, mount of water that will drain out of those deposits by or most industrial uses, although it is used for stream^ lowering the water level to their base. electric plants, as raw water to produce salt by solar evaporation, and for the disposal of sewage. For several reasons not all of this storage capacity may be susceptible to economic use. Therefore, usable storage capacity is defined as that portion of the stor Records of Streamflow age capacity that can be economically dewatered during dry periods and resaturated during wet periods. In The San Francisco Bay Area does not contain any view of the many geologic and economic factors invol one dominant stream. However, the Sacramento and ved in estimating usable storage capacity, it has not San Joaquin Rivers discharge into streams at the east been estimated for all the basins in the San Francisco ern end of Suisun Bay near Collinsville outside of the Bay Area. San Francisco Bay Area. The three major streams in the area are Alameda Creek, Napa River, and Coyote Table 3 shows the gross storage capacity of the Creek, with a total drainage area of about 1, 520 square basins for specified depth intervals. Although these miles or 38 percent of the land area. The combined figures are not necessarily usable storage, they pre runoff of these three streams represents about 30 per sent a relative comparison of amounts of water con cent of the total runoff of the area. Table 3. Estimated gross ground-water storage capacity, in acre-feet Depth zones, in feet below land surface Area Ground-water basin in Total of all zones 1.0-50 15-50 25-100 50-100 100-200 lacres 10-200 15-200 25-200 Santa Clara Valley...... 86,500 559,000 684,000 1,250,000 Livermore Valley...... 39,000 ...... 219,000 241,000 ...... 460,000 20,800 47, 000 68,000 111,000 226,000 39,700 78,000 65,000 104, 000 247,000 Sonoma...... 16,500 44,000 ...... 54,000 87,000 185,000 Petaluma ...... 12,050 51,000 62,000 95,000 208,000 12 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA Streamflow information is currently obtained by the flood volumes to any significant degree. Floods are Geological Survey at 24 gaging stations in the San usually of short duration and normally do not cause Francisco Bay Area and at other times 28 additional great damage. stations have been operated. The duration of published records is shown in figure 7. The locations of the At times, however, outstanding floods have occurred. stations are shown on plate 2. Records going back to 1787 mention storms during the winter of 1798-99 which were reported to have lasted for 28 days, and rains of January and February 1819 Floods which caused floods that changed the courses of many The San Francisco Bay Area is rarely subjected to streams. area-wide floods. The mountains and bays subdivide the area into relatively small and independent valleys The floods of 1861-62 caused considerable damage thus eliminating the cumulative effect that might be in the towns of Napa^Atvarado, and San Leandro, and found in a single-stream system. inSanMateo and Santa Clara Counties. InDecember 1867, Petaluma Greek was the highest since the town of Floods on the various streams in the area are Petaluma was settled. Floods on the Napa River and caused by intense rains. Available records show that Petaluma Creek in January 1881 exceeded any other melting snow has not affected flood peak discharges or known flood. During the 1889-90 season, the greatest Index Drainage Number Water year ending September 30 Area Gaging Station (PI. 2} (sq. mi.] 1 46.2 Pescadero Creek near Pescadero 2 Los Trancos Canal near Stanford University 3 7.5 Los Trancos Creek at Stanford University 4 Lagunita Canal at Stanford University 5 35.7 San Francisquito Creek at Stanford University 6 38.5 San Francisquito Creek at Menlo Park 7 38.6 San Francisquito Creek at Palo Alto 8 8. 10 Matadero Creek at Palo Alto 9 18.0 Stevens Creek near Cupertino 10 35.1 A lam it os Creek near Edenvale 11 12.7 Los Capitancillos Creek at Guadalupe 12 43.6 Los Gatos Creek at and below Los Gatos 13 151 Guadalupe River at San Jose 14 8.97 Saratoga Creek at Saratoga 15 194 Coyote Creek near Madrone 16 Coyote Creek at Coyote 17 - 10.8 Laguna Seca near Coyote 18 229 Coyote Creek near Edenvale 19 Coyote Creek at San Jose 20 10.8 Laguna Creek at Irvington 21 33.1 A lame da Creek near Sunol 22 100 Calaveras Creek near Sunol 23 Spring Valley Water Co. 's aqueduct near Niles 24 39.7 San Antonio Creek near Sunol 25 40.4 Alamo Creek at Dublin 26 27.9 Tassajera Creek near Pleasanton 27 69.5 Arroyo las Positas near Livermore 28 38.3 Arroyo Mocho near Livermore 29 149 Arroyo del Valle near Livermore 30 412 Arroyo de la Laguna near Pleasanton 31 622 Alameda Creek at Sunol 32 Alameda Creek at Niles Dam 33 633 Alameda Creek near Niles 34 Crandall Slough near Centerville 35 Alameda Creek near Decoto 36 Dry Creek near Decoto 37 - 38.0 San Lorenzo Creek at Hayward 38 San Pablo Creek near San Pablo 39 San Pablo Creek at San Pablo 40 - 5.89 San Ramon Creek at San Ram on 41 50.7 San Ramon Creek at Walnut Creek 42 78.1 Walnut Creek at Walnut Creek 43 20.8 Pine Creek at Concord 44 81.3 Napa River near St. Helena 45 52.3 Conn Creek near St. Helena 46 17.4 Dry Creek near Napa 47 18.0 Dry Creek near Yountville 48 Napa River near Napa 49 29.6 Petaluma Creek near Petaluma 50 17.2 Novato Creek near Novato 51 18.3 Corte Madera Creek at Ross 52 - 36.2 Arroyo Nicasio near Pt. Reyes Station Figure 7. Duration of published streamflow records in the San Francisco Bay Area. OCCURRENCE OF WATER 13 precipitation on record occurred at many points in minerals, chloride and boron content, and the the San Francisco Bay Area. On January 24 and 25, percent sodium 1 . They are interested also in the 1890, the flood near San Jose was the greatest since chemical composition of the irrigation water be 1862, and probably has not been equaled since. The cause it is related to soil structure and crop 1890 flood on the Napa River at Napa was reported growth. to be only a foot below the record height set in 1881. In March 1907, floods of Los Gatos Creek and other Maximum allowable concentration of some constitu streams in the Santa Clara Valley were especially ents in potable water to be used by interstate carriers severe and flooded land near San Jose. Alameda have been established by the Public Health Service as Creek, as a result of this flood, was as high as it follows: had been in, 1895. ppm In addition to those floods mentioned above, floods Iron plus manganese...... 0. 3 of moderate extent occurred in some portion of the Magnesium ...... 125 San Francisco Bay Area in 23 different years since Sulfate...... 250 1849. Chloride...... 250 Fluoride...... 1. 5 The flood of January 12, 1952, was the highest Dissolved solids...... 3 500 in Alameda Creek during the period of record which started in 1916, and probably the highest a l, 000 ppm permitted if water of better quality is since the flood of November 1892. Storage capac not available. ity of 96, 900 acre-feet has been effective since 1925. To the industrial user, the quality of water is often of greater importance than the quantity. The cost of Conservation and flood-control reservoirs in many treating water of poor quality sometimes exceeds the of the basins reduced the peak discharges that other cost of developing an original supply. Quality require wise would have resulted, but nevertheless, damage ments for process water are often critical and the from the 1952 flood amounted to about $1,400,000 water must frequently be modified to meet specific in the Stevens Creek, Gaudalupe River, Saratoga requirements. Creek, Alameda Creek, and San Lorenzo Creek basins. The chemical quality of stream water in the San Francisco Bay Area is generally suitable for most Flood waters from many storms have been retained domestic, industrial, commercial, and irrigation use. in reservoirs operated by the Santa Clara Valley Most of the rivers and streams have low to moderate Water Conservation District since about 1935 for concentrations of total solids. Alameda Creek and its subsequent release at controlled rates to replenish tributary streams are the main exceptions. For pur the ground-water supplies. poses of this report, the classification of total concen tration of waters is as follows: Precipitation records and historical accounts in dicate that the San Francisco Bay Area has not ex Specific perienced a major or area-wide flood since 1889 90. Concentration conductance Most of the streams in the area have no storage or (micromhos)a insufficient storage to control major floods. In the event of an outstanding flood, those industrial and 0 - 150 residential developments which have encroached on 150 - 400 the flood plains can expect damage. 400 - 1,000 High...... :...... 1, 000 - 2, 500 Figures 13 and 16 are flood frequency curves for over 2, 500 Alameda Creek near Niles and the Napa River near St. Helena, respectively. a Reciprocal of ohms times 10^ In general the surface waters are of a calcium bi Significance of the Chemical and Physical carbonate type and many are high in calcium and mag Characteristics of Water nesium hardness. The surface and ground waters in the San Francisco The total concentration of the rivers and streams Bay Area have many uses and it is difficult to devise a varies greatly due to the seasonal variations in precip single set of standards for all uses. Water consid itation. During the winter, heavy precipitation in ered good by one consumer may be considered poor creases streamflow and total mineral concentration by another. Water use in the area can be divided decreases. In the dry season of summer and fall, roughly into three classes; domestic, industrial, and streamflow decreases and the concentration increases. irrigation. Domestic consumers are mainly con Figure 8 shows the maximum and minimum recorded cerned with the hardness, iron, manganese, fluoride, concentration of chemical constituents in selected sur nitrate, and sulfate content and the sanitary quality face waters in the area. A large range in concentration of the water. Industrial consumers are interested was observed for all of the streams except Coyote in the total dissolved minerals, hardness, alkalinity, hydrogen ion concentration, turbidity, color, and I/One hundred times sodium divided by the sum of corrosiveness of the water. Irrigation consumers sodium, calcium, magnesium, and potassium, all ex are interested primarily in the total dissolved pressed in equivalents per million. 14 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA of ground water is pumped from the narrow, sloping plain adjacent to the bay. With the exception of Pescadero and San Francisquito Creeks, most of the streams on the peninsula are small. The principal streams draining into the ocean are Pescadero, San Gregorio, Tunitas, Purisima, Pilarcitos, and San Pedro Creeks. Those on the bay side are Colma, San Mateo and San Francisquito Creeks. All of this latter group except San Mateo Creek enter San Francisco Bay through tidal marshes. Surface Water Pescadero Creek is in a canyon for most of its length; only the lower 5 miles of channel are in open country. Average annual precipitation in the basin ranges from D about 19 inches along the coast to 45 inches in the moun Sodium and Calcium Sulfate, nitrate tains, and the annual runoff averages about 12 inches. potassium and fluoride The drainage area above the gaging station near Pescadero is 46.2 square miles, or 77 percent of the Magnesium Chloride Bicarbonate entire basin. Figure 8. Maximum and minimum concentration of chemical constituents in selected streams in the San Discharge^ Francisco Bay Area. Streamflow records have been obtained on Pescadero Creek. This stream has a controlled flow from a regu Creek since April 1951. The mean discharges for the lating reservoir which effectively reduces large varia water years 1952 and 1953 were 59.6 mgd (92.2 cfs) tions in quality. and 28.5 mgd (44.1 cfs), respectively. The maximum discharge was 3,440 cfs on Dec. 7, 1952, and the min imum was 0.71 mgd (1.1 cfs) on Oct. 4, 1952. WATER SUPPLY OF SUBAREAS Flow characteristics of Pescadero Creek are shown The 8 major ground-water basins in the San Fran by the flow-duration curve (fig. 9). A flow-duration cisco Bay Area are the alluvial deposits in Santa Clara curve based on a short period of record will not show Valley, southern Alameda County, Livermore Valley, the flow characteristics of the stream unless stream- Ygnacio and Clayton Valleys, Pittsburg plain area, flow during the short period was about normal. The Suisun-Fairfield area, and Napa, Sonoma, andPetaluma flow-duration curve for a single year may be quite dif Valleys. ferent from the curve for several years. (See fig. 11.) The duration curves shown in this report have been ad The most important streams in the area are Coyote justed by statistical methods to the period 1932-53 by Creek, Alameda Creek, and Napa River. Many streams using records of nearby streams and may be considered have retention reservoirs to replenish ground-water to represent about normal streamflow. The flow- basins by controlled releases of water. The estimated duration curve may be used to show the percentage of mean annual runoff of the San Francisco Bay Area is time that a specified daily flow in million gallons per about 1,250,000 acre-feet, and since water year 1895 day or cubic feet per second probably will be equaled it has ranged from about 90, 000 acre-feet in water or exceeded. year 1924 to about 3, 100, 000 acre-feet in water year A gaging station was operated on San Francisquito 1907. This runoff is not distributed evenly throughout Creek, from 1931 to 1941 and since 1950. (See fig. 7.) the year; about 80 percent of the runoff occurs between Some discharge data for this stream is given in table 4. November 1 and May 1. Stanford University obtains water for irrigation on Supplemental water supplies are brought into the area the campus throvg- a pipeline from Searsville Lake from the Sacramento and San Joaquin River basins by (capacity 952 acre-feet,) on San Francisquito Creek, means of the Mokelumne and Hetch Hetchy aqueducts, and from Los Trancos Creek by way of the Lagunita the Contra Costa Canal, and by diversion from Cache and Los Trancos Canals. Slough. (See pi. 5.) San Mateo County Analyses of water from several streams in San Mateo San Mateo County is on SanFrancisco peninsula, be County are given in table 5. Most of the streams have tween the Pacific Ocean and the bay. A small amount been sampled during periods of high flow and low flow. DISCHARGE, IN CUBIC FEET PER SECOND C/J g CO *-» ISi CO b b b b b b b . . . . I"1 h-> N> CO £ Ol fl) 00 O Q Q ho co K cnoivioo -' N> CO .£> Ol Ol 00 O N> CO^OlOlOOO O OOOOOO O O f JrS 8 i i i i i i i i i i i i i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 111111111(1 I 3 » i'3 /~\ o *^ ^ w rt o> ^ " ' 5" £ ^ "e o 3 & ET O in »u 5. "* n\ J 5" o hi ** b O R o"E o '- < ' CO a D tt £ o » o c o" Ol 1 - IM - -« X t a V / f m ;o / 5 / / H OC ' >_ n 5 ^ CO 8 o / CO C 0-n X / >1 0) _ _ T 0) i-J 0 CD CD * si i K \ - OO Ol ^~" o 5" £ m £\ ' T f *"* HJ a. ^ s / a 0 H § 5 Ol Ol ^^ i.^ d o ^ f n> r X s'X Ol ^ 20 ^ CO SB D (TO X / / < 0) g 8 c x / 3 2 S ^ 00 rf>. in m c ^ X ^ a, o C CO in K^ O 3- > 0 / ^^ >) SB 4 m p- t> l-» tO O 1 O j-,. / Adjusted2"yearswater1932-53to to -» & ^ (Oct.1.Seot30.1953)1931to F! - y °s 5 0 ° -'^ / o Ol -J c 20 ^^ n 3 h- rn o * d -' CO c 0 ^^ ^ CO 00 "o" g- -- / 5 /" oo 01 en 5T i° ^ -^ CD OO Ol m ^- ' ^. 4 SB c \ O Ol O m / (D X c H O n X ^ D ^ 3 < 0) 0) O c ( X cr p < 3 co o d 5 \ tO !- O / oo en oo £- ( ** " *" ft* H 1 0 x CD CD CO n rfi Ol Ol ? ? O CO O D / 3 d <£> Ol percent95foroftimethe mgdgreaterto,than0.85or D 00 O ' equalPescaderoCreekwillbe f ! / \ J ET ET o* ~~"in S3' <£> n> 00 u r § M M 3 a OP SB c $ wo o i rt- p- p- d 3 s i SB Ol ro *fD *« nT 10 ^ P SB UD M ^ ^ 16 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA O5 t- 1-1 oo t- * CM m oo m D-* D-* t-' t-' t-* t-* a oo t-' e- e- c-' oo co e- CM CO oo o CO CD m o O5 CD o co §1? CM m oo oo CO O> 1-1 O CM O5 CM m * m m t- m co m co CM CM CM CM - o m -£|« OT 0 m oo m CD o> oo * CM O O3 m t- ^ o> Tt< CO CM CM CM CM CO CO CM CM CO CM co ^ 0 PU ls| CM CM CO CO o o m CD m o t- CO a> a* CO CO m t- m CT> CO CO C !-. rt CQ <« 0 ni C CQ O J3 0 U m rt< ^ CO oo m 35 i-l CO CM O 05 ^ t- CD m t- U u "cfl CD i 1 CO ,-1 c- oo o> m O) CD "o i-l CM CM CO .-I CM i-l CM r-t i 1 ffi W 33 cfl CO i-l We 1 -1 CD e- CO CO T) C M 0 O CO Tt< in CD ^ t* <* m CO ^ CM CM i-l CM 0 0 !- 0 o* I," H c^*2 O 0 o o o ° id CQ o t- 1-1 CO CO ^ CO CO C35 oo co i-l CM CO Tt< 2 w U ri C CD -* c- o> in co i-H t- m 03 t- m co m Cfl h « -s .2 CM CO CO ^ co in CO CO i-H i 1 cfla i 1 i-H Q £ a g^ 0 03a Q CM CO 00 00 o in CO CD 0) ^ CD o oo iH -* CM O i-l i 1 i-H Beach3 0 0 O O i r-t CM CQ O O o o Fromn T) o o 2" 0 0 o o o 0 c o 0 "o 0 O CQ h PQ 0 rt 0 o i-l CO o in CO CO t- .-I 1-1 m Pescac c Cfl "3 cfl 3 i "co Lhouse H CM* "a J"J6 crCu C ) CO O3 in o CM CD t* <4< o> ^ CM CO in o rt< m in c- ^ CD in t- CO Tt< CM i-H i l CM o CO Tt< §£ CM »H o o 1-1 O 0 0 .-i O O CM oja* J-t IT I 0* 0* o o o 0 flJ rsj CD CO o co CM CM CM O O CM i-l CO ,-1 0 £0 CM CM CO CM CM CM CM CM CM CM CM CM CM CM W £ 0 1 fcfi-T- a) w b «2 0 ~* Cfl Q O co.co" co' co CO CO* CO CO CO CO CO CO CO CO _a collection m in m m m in m m in m m m in in of 0) 03 O3 O3 O3 O3 o> 01 O5 O3 O5 O5 i 1 i 1 i i i i 00* O* oo* c" CO* O* co* o" co'o* O* CO* c CO* CT> CM rH CM r-t CM i-l CM i-l CM rH i-H CM CM . 0 . 01 . 0 . 0 . 0 . c c c c C C C C £ c C C || cfl 3 ni 3 1-5 1-5 1-5 !-s 3£ 33 Vicente Creek - South of Moss Beach, Bridge Crossing, East of Highway no 1 Jan. 28, 1953...... 23 0.4 12 5. 3 24 0.7 51 12 33 0. 3 4.2 0.01 140 0. 19 52 10 50 217 7.4 June 9,1953...... 22 .0 18 5.9 25 .4 70 11 38 .5 1.6 .03 157 .21 69 12 44 254 7. 3 San Pedro Creek - Outlet to Ocean Jan. 27, 1953...... 16 0.0 23 11 21 1.0 110 17 28 0. 3 3. 7 0.01 175 0.24 103 12 31 300 7.3 June 9,1953...... 16 .0 26 12 21 .7 126 17 28 .2 1. 5 .02 184 .25 114 11 28 314 8.2 Los Gatos Creek Near Los Gatos Oct. 2,1952...... 0.5 18 ,0.00 35 39 20 1.6 248 54 18 0.1 4.0 0.09 312 0.42 248 45 15 531 7.8 Nov. 12, 1952 a ...... 1.4 266 18 OCfl 538 8.0 Dec. 16, 1952a...... 27 194 15 227 501 7.7 Jan. 21, 1953...... 26 33 17 12 1.2 146 12 1 S9 33 15 344 7.8 Feb. 16, 1953...... 40 35 15 13 1.6 148 8.0 149 28 16 338 7.6 Mar. 26, 1953...... 55 28 14 11 r 154 8.0 1 16 oqe 7 ^ 3-34 Apr. 20, 1953...... 58 36 15 12 151 8.5 1 RO 28 15 8.1 May 13, 1953...... 56 38 .0 18 9.2 16 2.2 102 13 12 . 3 4.4 .24 163 .22 83 0 29 234 7.8 June 19, 1953a ...... 10 208 10 .03 210 15 448 8.1 July 15, 1953a ...... 3.3 224 16 .08 000 15 491 8 r\ Aug. 18,1953...... 3.5 46 21 15 1.6 216 10 201 24 14 435 8.2 Sept. 24, 1953...... 3.7 14 b. 12 44 19 16 1. 3 200 37 9.5 .2 .4 .10 240 . 33 188 24 16 399 8.2 Coyote Creek Near Madrone Oct. 20,1952...... 42 12 0.00 28 11 14 1.8 126 25 11 n 9 0.5 0. 11 166 o 97 115 0 21 272 7.6 Nov. 12, 1952 a ...... 46 130 8 118 284 7.8 Dec. 16, 1952 a ...... 66 133 7 117 97c 7.7 Jan. 20,1953...... 60 35 14 16 2.0 156 10 1 4.S 17 1 Q 341 8.0 Feb. 16, 1953...... 7.0 35 19 17 1.9 179 12 165 1 Q 18 374 8.3 Mar. 25,1953...... 53 31 16 16 162 12 143 10 Of) 339 7.8 Apr. 21, 1953...... 56 34 14 16 160 9.5 .05 1 4? 11 20 334 7.9 May 13, 1953...... 46 8.6 . 1 32 16 15 2.2 160 31 10 .2 1.0 .10 195 .27 146 15 18 339 7 Q June 18, 1953a ...... 33 160 10 .07 148 18 324 8.1 July 15, 1953*...... 52 166 11 .08 146 1 Q 332 7.8 340 Aug. 18, 1953,...... 44 34 16 15 2.2 170 9.0 .06 151 11 18 7 0 Sept. 24, 195a...... 52 9.0 b.20 33 17 15 2.0 171 28 10 . 3 1.1 .06 200 .27 152 12 17 349 7.8 Alameda Creek Near Niles Oct. 21,1952...... 2.0 15 0.00 78 52 79 4.9 398 140 75 0.2 0.1 0.82 640 0.87 408 82 29 1040 8,0 Nov. 12, 1952a...... 1.8 436 71 404 1015 8.4 30C Dec. 16, 1952a ...... 13 305 88 J3QCL 8 Q 9-3 f| 3f| 3f| 1 Jan. 20,1953...... 278 53 24 45 2.7 244 39 611 8 Feb. 16,1953...... 36 69 44 77 4.0 358 73 353 60 30 OKA 8 0 See footnotes at end of table. 18 WATER RESOURCES OF THE SAN FEIANCISCO BAY AREA 03 -H K CO O3 CO O3 CO O O3 to m to CO CO Tf t- co co co co co co CO co co co co CO co co CO o CO O3 Specific conduct- o rt ,-. ^ o o co co o o CO o o o M C1* O tO rH tO t~ Tf CO c- co co co CO co c- CO O O O5 O5 O rH O5 o to rH to H '2 2 Si rH rH rH rH O3 « g -g (N i t- 0 CO C7> lA CO C>Q rH O C7> CO in n S , | N CO CM 0 a; o .2 >3 CO CO CO CO CO C"Q m C£J c w -3 co o co co t- I ! co t- o to o o O m i> C t< "S Tf m m ; ; m to O3 m to ssolved c ^ i o co 03 to to D- oo m O5 CO CO to oHds ° Q. 0 C o" o d o d o* to U Tf 00 o o to oo P 5 s; a I m a> to CO o CO p_j *~" c p * rH ______CO O rH rH O3 CO OO D- tD o i o CO 03 c o S" Tf m D- to o to oo o o o o D- O 0) CD 0) CO tD PC r~t CO o I-1 0 ed 0 0 O o o TJ a 0) D- <1 o O5 to 0) "o O5* r-l 0) o "to O3 o o d OO iH £ "ed 0) o 0) J 2 ed if H o r-l c ed O o s U CO c "S 0) o O _o o a to "tn o" f-H H la *£ i^. o 0) § d rH 0) d n "So o d d ed s a) iH a 0) 1 rd M o c tn rd M M CO t 3 ^ 01 03' ed ed m m t~ t- O3 'O5 O3 O OO rH cfl (M o co CO £ C 0) 0) g H ^ m 03 co co * t- 03 Cfl O3 o CO § O3 tn rd m to O3 03 fll ^ ed ; ; 03 ; ; 03 0) o to 0) 0) 0> 03 01 rH 0) O5 0) rH 03 ao 00 '"30 0) rH M i 1) «*-! cr: M ffi 1) U 0 "5 0) 01 \ (;etwater U i- .22 'co 01 M m to Hayetano ttonwood* o CO CO ^ D- O3 O3 a i cfl Q rH O3 CO O O O3 tD U D- O3 "3 r- 0) CO O3 > C rj U (D 00 m CD c. -o "* "* M d >r-l 0) 0) 00 4? edo "ed M $ H U o U V "S a U U orenzo CO 03 -*-a cfl * : CO CO rH O3 1 oo o r-l B 3 "vTJ\ o i> H IT- CO oo D- O (1 ' to 5 to CO (M te S33 5S CO CD 00 CO 03 ; g __ rH 5 !^ O 0 CD W C*- lO O_> to o 03 O3 -; -3 Q co co r* co oo S 03 m m CO CO : :o : i :§ ; -, CO (M g « r- 3 O OO O es ^ -f-t O3 i/j c/^ 03 3 O3 0) ed ^* O O3 rH O (1) D- O in CO 03 03 03 03 rH o I | co' o : : : cfl cfl : : CO* CO* CO* CO* CO* iH CO CO CO CO CO CO CO 0) m m m m m m m m m m m m m m m CD 03 03 Id O Jan. 29,1953...... 13 52 32 31 1.2 275 51 34 0.2 3. 1 0.06 353 0.48 261 36 20 605 7.8 Jan. 11, 1954...... 13 46 30 27 2.2 265 32 28 .2 2.3 .67 311 .42 238 22 20 544 7.9 San Ramon Creek Southeast of San Ramon Feb. 19,1953...... 19 0.0 89 16 33 1.3 318 61 24 0.3 3. 3 0. 13 404 0.55 288 28 20 652 8.2 Walnut Creek 50 Feet Downstream at Ygnacio Valley Road Feb. 19,1953...... 11 0.0 95 34 81 2.3 384 134 60 0.3 1.9 0.26 609 0.83 377 62 32 985 8. 3 Napa River Near St. Helena Oct. 20, 1952...... 0.5 32 0.00 38 17 20 3.3 198 24 12 0.1 2.3 0.28 246 0. 33 165 2 20 385 7.6 Nov. 14, 1952 a ...... 2 O 184 12 154 380 7. 3 Dec. 15, 1952a...... 103 66 9 62 183 7 3 Jan. 19,1953...... 919 11 5.8 7.4 1.9 63 5.2 51 0 23 136 7. 3 Feb. 11,1953...... 48 18 7.8 14 6.9 93 10 77 1 26 219 7.6 Mar. 11,1953...... 32 19 9.9 18 107 16 .18 88 0 31 255 7.4 Apr. 17,1953...... 33 18 8.3 16 100 12 .24 79 0 31 229 7.7 May 18, 1953...... 26 14 .0 37 16 13 1.8 156 44 8.5 .2 1.3 . 11 213 .29 158 30 15 354 8.0 June 17, 1953a ...... 10 128 14 .30 108 27 255 7.5 July 13, 1953a ...... 4.0 158 13 .29 146 91 348 7.2 Aug. 14, 1953...... 1.3 31 19 16 1.8 C179 10 .22 155 9 18 362 8 4 Sept. 24, 1953...... 1.5 31 .01 33 17 17 1.9 183 23 12 .2 3.2 .27 228 . 31 152 2 19 358 7.9 Petaluma Creek at USGS Station, Willowbrook, Corona Street Bridge Mar. 11,1954...... 19 33 18 31 11 150 32 54 0.4 3.0 0.15 275 0.37 156 33 28 491 7.4 Novato Creek Mar. 11, 1954...... 15 24 16 22 5.9 125 21 34 0.2 8.8 0.00 208 0.28 126 OQ 26 367 7.4 Apr. 1953 k ...... 26 11 6.7 64 32 17 .2 .2 125 .17 108 12 a Analyses by Division of Water Resources, State of California g Includes equivalent of 26 parts per million CO3 (carbonate) b Total iron hIncludes equivalent of 8 parts per million COs (carbonate) c Includes equivalent of 5 parts per million COs (carbonate) 1 Includes equivalent of 7 parts per million COs (carbonate) "Includes equivalent of 23 parts per million CO3 (carbonate) J Includes equivalent of 18 parts per million COs (carbonate) e Includes equivalent of 36 parts per million CO3 (carbonate) * Analysis by Marin County Health Department * Includes equivalent of 33 parts per million CO3 (carbonate) 20 'WATER RESOURCES OF THE SAN FRANCISCO BAY AREA During, the winter, when the streamflow is high, the period of the early!940's. In 1943 the water levels began waters generally have a-lower concentration than dur to fall and the average reached a record low of nearly ing the summer. The waters are generally of the 25 feet below sea level in the autumn of 1950. Levels calcium and magnesium bicarbonate type. began to rise in 1950 and were still rising in 1954. Pumpage Santa Clara Valley The total ground water pumpage during water year Santa Clara Valley is an elongate valley that extends 1949 was estimated to be 231,600 acre-feet; irrigation about 50 miles southeastward from San Francisco Bay. use amounted to 197, 500 acre-feet; urban use was The valley is separated into a northern and southern 31,800 acre-feet, and other uses totaled 2,300. Ac part by a low ridge of hills about 25 miles south of the cording to estimates by California Division of Water Bay. This report is concerned only with the northern Resources the ground-water withdrawals in 1948 49 part of the valley. The width of the northern part created an overdraft of 36, 700 acre-feet. Excessive ranges from about 15 miles at the north end to less pumping in Santa Clara Valley develops two potentially than a mile at the southern end, and has an area of serious problems; one is salt-water encroachment about 250 square miles. The major streams of Santa from San Francisco Bay, the other is land surface sub Clara Valley are Guadalupe River and Coyote Creek. sidence that causes many engineering problems. Salt-water encroachment Ground Water In Santa Clara Valley the normal hydraulic gradient The formations in Santa Clara Valley are divided into of the confined water body is toward the Bay. However, three groups, as shown on plate 1, based on their rel the gradient has been reversed at times because of the ative water-yielding properties. The Quaternary al excessive lowering of water levels due to heavy pumping luvium, (fig. 10) uppermost and youngest group of the during dry periods. During the autumn of 1949 water threefold classification, is composed of sand, gravel, levels in some areas were more than 800 feet below and clay, and the maximum thickness is about 1, 000 sea level. feet. The alluvium is the main source of ground water. Encroachment of saline water may deteriorate the con The intermediate group of rocks, referred to as the secondary aquifer, consists of the Santa Clara forma fined ground-water body in Santa Clara Valley if the Bay tion of Pliocene and Pleistocene age. This group con waters have access to the deep water body. Studies by sists of a maximum of 4, 000 feet of continental sand, Tolman and Poland in 1940 showed a fringe of salt-water gravel, silt, and clay. The third group is essentially encroachment from San Francisco Bay. These in non-water-bearing rocks that range in age from late vestigations indicated that contamination was caused Jurassic to middle Pliocene. chiefly by movement of salty perched water through de fective and abandoned wells, and through gravel deposits Ground water in Santa Clara Valley occurs in both of streams draining into the bay. Salt-water encroach confined and unconfined conditions. The area of con ment was primarily restricted to gravels less than fined water, approximately 78,600 acres, extends from 100 feet below the land surface. Impervious layers of about 4 miles southeast of San Jose to at least several clay prevented percolation of salt water below this depth miles north beneath San Francisco Bay, and from near except where the clay had been punctured by wells. Many Palo Alto on the west to near Milpitas on the east. It of the old wells have been plugged to prevent percolation is overlain by a body of semiperched water. The area to the principal water body. Studies made by the California of unconfined water, about 86, 500 acres, is upslope Division of Water Resources in 1949 indicated that no from the confined area and extends to the foothills. significant inflow of saline water has occurred in Santa Clara Valley, and that the principal water body has not become contaminated, with the possible exception of the Yield and depth of wells area near Palo Alto. The depth of wells in Santa Clara Valley ranges from Land-surface subsidence less than 50 feet to about 1, 000 feet with most being from 300 to 500 feet deep. Because of the wide range The land surface in certain areas has lowered nearly in well depths and amount of water-bearing material 8 feet between 1912 and 1954. This sinking is limited penetrated, well yields also range widely, from less to areas underlain by the confining clay bed, and covers than 50 gpm to nearly 2, 000 gpm. Most of the wells an area of about 120 square miles. produce 400 to 600 gpm. This area was resurveyed 10 times between 1933 and 1940, and again in 1948 and 1954. The rate of subsidence Water-level fluctuations was not uniform over the area. The greatest subsidence during the 15-year period from 1933 to 1948 was about The hydrograph for Santa Clara Valley on figure 5 l\ feet at Sunnyvale. The maximum subsidence in Santa is a composite of records from 250 wells distributed Clara Valley for the 6-year period from 1948 to 1954 throughout the valley, and measured by the Santa Clara was 2.5 feet. The subsidence is believed to be due Water Conservation District. The average water level chiefly to the compaction of silt and clay layers caused is plotted as altitude above sea level. During the early by the decrease in hydrostatic pressure. 1900's, when irrigation was becoming important, the water levels were more than 100 feet above sea level. During the drought of the early 1930's the average water levels dropped to slightly above sea level. The water Most of the ground water in the Santa Clara Valley is levels rose almost to their original height during the wet a calcium bicarbonate type. (See table 6.) Some wells B' Figure 10. Generalized geologic cross-sections of ground-water basins. For location of sections see pi. 1. Table 6. Selected chemical quality data lor ground waters in the San Francisco Bay Area [Analytical results in parts per million except as indicated. Water-bearing formations: Qal, alluvium; Qh, Huichica formation; TQge, Glen eien formation; TQm, Merced formation; Tp, Petaluma formation; Tsv. Sonoma Volcanic formation] Dissolved Hardness as Specific Water Temp Cal Magne Potas Bicar Chlo Fluo- Ni solids CaCQs Pier- conduct Depth Silica Sodium Sulfate Location bearing erature Date of collection cium sium Boron cent ance (in feet) (°F) (SiC-2) (Na) sium bonate (S04) ride ride trate so- (micro- PH formation (Ca) (Mg) (K) (HC03) (Cl) (F) (N03) (B) Sum Total mhos at 25'q) Santa Clara Valley 66.2 26 M OQI: cn 6SAE -4M1 ...... 69.8 Aug. 11,1953...... 28 89 38 85 2.2 472 52 73 .4 19 .07 619 378 33 1020 8.1 6SAE -30M1 69.8 Aug. 11,1953...... 29 68 264 21 612 6SAW-14L4 66.2 Aug. 11, 1953...... 27 86 24 56 1.4 .06 OfO 00 1QO 6S/2W-21B1 64.4 Aug. 12,1953...... 29 89 70 OOQ 7 Q 6Sy2W-36H2 68 Aug. 12, 1953...... 27 95 340 17 752 6S/6W-1D1 750 72 Sept. 23, 1952...... 30 34 11 118 1.6 34 .2 i in TAQ 8 rt 7SAW-3G1 69.8 Aug. 11,1953...... 29 66 19 22 1.2 238 61 16 .1 5.6 .09 337 242 16 534 7.8 Plain - Niles Con^ Area (WaL^is probably from tiic upper body, chloride txceedi. 25 percent of 3S/2W-33G2 62.6 Aug. 5.1953...... 32 104 142 0.6 544 133 180 0.8 63 0.34 998 568 4SAW-19N1 259 Dec. 21, 1953...... 19 116 35 28 262 58 170 .0 8.7 17 4SAW-30N3 ...... 250 ...... Dec. 9,1953...... 23 295 93 70 4.6 314 89 650 .0 11 .35 1390 1120 12 2570 7.6 240 26 200 69 67 58 16 7 C 4S/2W-24L2 240 Dec. 14, 1953...... 126 52 46 2.5 282 220 .29 528 16 5SAW-5K1 ...... 240 ...... Dec. 14, 1953...... 25 56 17 106 4.4 266 39 137 .0 2.1 .24 518 210 52 917 7.6 Alameda Plain - Niles Cone Area (Waters Probably from the lower body, chloride less than 25 percent of anion equivalents) 3S/2W-31B3 Aug. 5, 1953...... 9 Q cn AQft 4SAW-20N2 500 De . 9,1953...... 16 58 23 32 63 36 OQQ 99 tQA 4SAW-30L5 ...... 518 ...... De . 16,1953...... 19 36 11 75 1.7 268 46 21 .1 .8 .37 343 135 54 556 8.1 4SAW-32L1 500 De . 16,1953...... 56 19 56 3.1 258 60 .21 218 36 681 4S/&W-35C1 ...... 519 ...... De . 14,1953...... 21 14 4.1 111 1.4 270 40 24 .1 .1 .30 349 52 82 572 8.1 5SAW-6H2 300 De . 14,1953...... 24 32 7.9 81 2.6 266 46 26 .1 .2 .23 351 112 60 569 7.7 Livermore Valley 64.4 Aug. 3,1953...... 26 70 17 52 1.1 300 11 63 0.1 2.2 0.07 390 244 665 2S/2E-35G1 ...... 77 Aug. 3,1953...... 21 44 24 228 .6 316 37 272 .9 14 3.1 800 208 70 1560 7.9 3SAE-5M1 "*40*6"" 62 July 15, 1952...... 27 32 18 167 .9 378 103 58 .3 .00 .50 592 154 70 951 7.9 July 18, 1952...... 16 237 48 554 3S/2E-4H1 68.0 Aug. 4, 1953...... 30 41 44 42 2.0 304 39 46 .1 22 3S>2E -22E1 445 July 15, 1952...... 30 49 64 85 1.6 a310 30 185 .1 30 .50 627 386 1120 8 6 4SAE-20K1 60.8 Aug. 4, 1953...... 28 72 21 87 .4 320 121 45 .3 .8 .17 533 266 41 839 7.6 Suisun-Fairfield Area ( Data furnished by Solano County Farm Advisor) 40 50 10 96 80 40 0.15 306 7 958 7 8 50 70 20 95 370 65 75 2.82 507 256 45 65 July 18, 1945...... 25 25 2J8 385 35 300 8.13 853 166 79 1660 8 1 5N/2W-17D2 72 Sept. 13, 1948...... 65 25 100 375 55 80 2.03 265 45 900 7 ?, 55 330 192 60 30 60 395 30 35 1.76 410 273 32 7.4 5N/2W-33R3 ...... 75 ...... Aug. 9,1946...... 120 75 170 740 180 130 ...... 1.27 608 38 1720 7.8 Napa Valley Qal...... 240 Feb. 2, 19SO...... 18 60 212 5NAW-15C2 9 5N£W-31A1 Qal...... 408 Apr. 8, 1952...... 29 6.8 3.6 205 1.5 488 0.7 65 0 0.2 5.3 32 854 8 3 5N£W-31A1 Oal 408 June 10, 1952...... 8.0 7.3 245 66 6.6 Qc»7 5N/6W-13K1 Qal...... 150 Sept. 20, 1951...... 16 24 19 28 .8 204 9.1 15 .1 .3 4.4 7 3 6N^W-16B2 TQge ...... 211 74 3.7 4.7 134 9.0 300 .8 60 .3 .5 7.7 445 28 88 8 2 6N^W-16J2 TQge...... 280 Oct 25, 1949C...... 15 10 90 d!61 23 70 4N£W-14Dl 540 July 26. 1949f...... 78 10 10 197 310 45 140 "'"z's" .75 636 67 87 957 7.4 4N£W-14D2 Qh.!!!"!!!!!!!! 620 ...... Sept. 7, 1951*...... 52 12 18 175 275 92 120 0 604 104 79 880 7.0 4N^W-14L1 Qk. 650 68 327 ...... 763 142 i coo 5N^W-2A2 Tsv...... 350 fp\ 76 9 1.0 295 60.1 2.9 392 7.0 845 96 5N^W-2A5 80 269 5.0 2.0 195 128 17 150 ...... 766 ...... 95 ...... Petaluma Valley 3N^W-1Q1 Qal...... 225 Apr. 1, 1952...... 24 9.2 15 13 0 98 25 3&S 5N/W-8D1&2 May 26, 1947n ...... 24 34 22 112 234 67 112 X 0. 07 0.8 58 7 Q 5N/TW-10Q1 Tp...... 462 Aug. 27. 1951C ...... 10 5 600 d276 10 705 5 8,5 5N//W-19H TQm...... 305 Dec. 9, 1949C ...... 60 10 30 185 10 IQft 24 7 Q 5N/?W-20B1 Qal...... 600 May 26, 1947h...... 10 12 5.8 101 188 22 58 i DP 16 81 COO 5N/7W-22Q2 Qal...... 97 Aug. 3,1949h...... 36 40 19 32 ...... 251 13 20 1 .10 0 **3*!"4 a Includes equivalent of 23 parts per million of carbonate b Analyses by U. S. Geological Survey, Salt Lake City, Utah c Analyses by U. of C. Division of Plant Nutrition at Berkeley, Calif. d Includes equivalent of 20 parts per million of carbonate (CO3) 6 Analyses by Pacific Engineering Co., San Francisco, Calif. Constituents converted from hypothetical combinations in grains per gallon to ions in ppm. f Analyses by Twelfth Naval District, San Francisco, California S Analysis by International Filter Co., Chicago, 111., converted from hypothetical combinations in grains per gallon to ions in ppm. h Analyses by California Water Service. San Jose. California | Manganese (Mn) j Includes equivalent of 4 parts per million carbonate (COS) D C B A Note: - The well-numbering system used by the Geological Survey shows the locations of wells according to the rectangular system for the subdivision of public land. For E F G H example, in the number 5S/3W-35G1 the numeral and letter preceding the bar indicate the township (T. 5S.); the numeral and letter between the bar and the hyphen, the range (R. 3W.); the digits between the hyphen and the letter indicate the section (sec. 35); M L K J and the letter following the section number indicates the 40-acre subdivision of the section, as shown in the accompanying diagram. Within each 40-acre tract the wells are numbered serially, as indicated by the final digit of the number. Thus, well N P 5S/5W-35G1 is the first well to be listed in the SWjNEj sec. 35. All locations in the Q R San Francisco Bay area are referred to the Mount Diablo base and meridian. 24 WAJER RESOURCES OF THE SAN FRANCISCO BAY AREA in the northern part of the valley and inland from the owing to storage developed as recently as 1950. Regu bay produce water of a sodium bicarbonate type. Except lation to promote percolation has produced periods of for the semiperched water body, the water is generally no flow at both gaging stations. of good quality and suitable for domestic, industrial, and irrigation use. Dissolved solids in the water samples ranged from 260 to 619 ppm and averaged 373 ppm. Total hardness as calcium carbonate ranged Quality. Samples of Coyote Creek water near Madrone were collected onqe a month from October 1952 to from 69 to 378 ppm and averaged 211 ppm, and percent sodium ranged from 14 to 67 and averaged 36. September 1933. The analyses are given in table o. The water is a calcium and magnesium bicarbonate type; having a low mineral content and is moderately hard. Surface Water Reservoir storage has an appreciable effect on water Guadalupe River quality. Storm waters entering the reservoirs dilute the more concentrated waters which had entered during The Guadalupe River drains an area of 223 square periods of low flow. The released water has a more miles. Altitudes range from sea level to 3,800 feet uniform quality than water of uncontrolled streams. above sea level at Loma Prieta. The total area above For example, Coyote Creek water below the reservoirs the gaging stations on Guadalupe River at San Jose and has a more uniform quality than many surface waters (fig. 8). Saratoga Creek at Saratoga is 160 square miles or 72 percent of the total area in the basin. Gaging sta Other streams tions are also operated on Alamitos Creek near Eden-- vale, Guadalupe Creek at Guadalupe, and Los Gatos Creek below Los Gatos. (See plate 2.) Discharge records have been collected on Stevens Creek since 1930 and on Matadero Creek since 1952. Average annual precipitation in the Guadalupe River Some discharge data for these streams are given in basin ranges from about 12 inches on the floor of the table 4. Stevens Creek Reservoir (capacity, 4,000 acre- valley to about 50 inches on the Santa Cruz Mountains. feet) is operated by the Santa Clara Valley Water Con servation District, and has impounded storm waters since 1936. The stored water is released at controlled Discharge. The average discharge of Guadalupe rates during the summer to replenish the ground-water River at San Jose for the 23 years of record (1930-53) is supplies by percolation into the gravels underlying the stream. 22. 8 mgd (35.3 cfs). The maximum discharge was 8,680 cfs on Feb. 27, 1940, and the stream is usually dry for several months each year. Artificial Recharge Artificial recharge is practiced by the Santa Clara Water Conservation District. The stored water is re Samples of Los Gatos Creek water below Los Gatos leased to canals that carry the water to permeable were collected once a month during the period October stream channels and to percolation ponds on the valley 1952 to September 1953. The analyses are given in floor, to infiltrate and become part of the ground-water body. table 5. The water of this stream is of the calcium and magnesium bicarbonate type; having a moderate mineral content, and is quite hard. Plate 4 shows the Coyote Reservoir (capacity, 24, 560 acre-feet) was variation of specific conductance, hardness, alkalinity, completed in 1936, and Anderson Reservoir (capacity, and chloride concentrations with streamflow. In gen 75, 000 acre-feet) was completed in 1950, both by the eral the relative proportion of the different ions in so Santa Clara Valley Water Conservation District. The lution remains constant even though the total concentra storm waters stored in these reservoirs are released tion varies greatly. Analyses of the sampled water at controlled rates to replenish the ground-water sup containing maximum and minimum concentrations of plies mainly by percolation and spreading near the dissolved solids are shown in figure 8. town of Coyote. The Santa Clara Valley Water Conservation District Coyote Creek operates several detention reservoirs in the Guadalupe basin to store storm waters which are released at con Coyote Creek drains 404 square miles of which 229 trolled rates to replenish the ground-water supplies by square miles are upstream from the gaging station percolation into the gravels underlying the streams. near Edenvale. Another gaging station is located near These reservoirs, all of which are upstream from the Madrone just downstream from Anderson Reservoir at gaging stations, are as follows: the mouth of the canyon. (See plate 2.) The highest altitude in the basin is 3, 600 feet on Pine Ridge north Capacity Date east of Morgan Hill. Reservoir Creek (acre- storage feet) began Discharge. Streamflow records on Coyote Creek 2,500 1936 date from 1902 near Madrone and 1916 near Edenvale Arroyo Calero.... 9,213 1935 and are among the longest records in the San Francisco Guadalupe...... 3, 500 1936 Bay Area. Maximum and average flows are not indica Los Gatos...... 25,000 1952 tive of what can be expected under present conditions WATER SUPPLY OF SUBAREAS 25 The total inflow to the Santa Clara Valley averages confined ground water. The confined conditions are about 204, 000 acre-feet annually. A much higher per formed in the vicinity of Pleasanton by at least four beds centage of the total inflow percolates underground dur of blue clay interbedded with gravel. ing a dry year than during a wet year. The winter of 1940 41 was one of the wettest seasons on record. The Yield and depth of,wells. Most wells in Livermore total runoff was 436, 600 acre-feet. Of this amount Valley obtain Water from the alluvium, and the average 145,600 acre-feet percolated underground; 107,300acre- yield of irrigation wells in the Pleasanton area, where feet by natural percolation and 38, 300 acre-feet by in the greatest pumping occurs, is about 500 gpm. A few duced percolation from conservation works. During wells produce 1,000 gpm.. The Pleasanton well field the season of 1944 45, a period of slightly less than consists of 25 wells which range in depth from 300 to normal rainfall, the total runoff was 132,000 acre-feet. 500 feet. Natural percolation amounted to 35, 300 acre-feet and induced percolation was 39, 700 acre-feet, for a total percolation of 75, 000 acre-feet. Water-level fluctuations. Hydrographs of wells 3S/1E-10Q1 and 3S/1E-10Q2 (fig. 5) are representative of wells pumping from the unconfined water body in Alameda County Livermore Valley. The hydrograph for well 3S/1E-20L1 shows the fluctuation for wells tapping the deeper con The principal areas of water development and use in fined water body. This well is used for municipal sup Alameda County are in Livermore Valley and the al ply and is about 500 feet deep. The depth to water -' luvial plain area along the east side of San Francisco ranges from about 35 to 100 feet below land surface. Bay." The major streams in the county are Alameda, The drawdown in the Pleasanton area was accelerated San Lorenzo, and San Leandro Creeks. from February 1948 to April 1949, by the pumping and export of 13, 600 acre-feet of water by the San Francisco Water Department. Although the pumpage by San Ground Water Francisco.Water Department has been nominal since the summer of 1949, increased pumpage for irrigation Livermore Valley during a period of low rainfall resulted in lowering of water levels to a record low in the fall of 1950. The Livermore Valley is 30 miles southeast of Oakland, following tabulation shows average depth to water in roughly midway between San Francisco Bay on the west subareas of the Livermore Valley during the fall of and the San Joaquin Valley on the east. The Livermore 1948, 1949, 1950: Valley has a maximum length of 13 miles in an east- west direction and is 3 to 5 miles wide with an area of about 60 square miles. The valley forms a broad plain Subareas within Livermore Valley 1948 1949 1950 sloping uniformly from an altitude of 600 feet on the east to an altitude of 350 on the west near Pleasanton. Pleasanton...... 94.0 Elliott...... 80.6 88.6 96.0 The syncline that forms Livermore Valley is devel 70.6 76. 3 78.5 oped in the Livermore gravel of Clark (1930) of Pliocene Dublin...... 35.0 39.4 42. 5 age. (See fig. 10.) This formation constitutes the aquifer of secondary importance in this area and is composed principally of sand, gravel, and clay, and Pumpage. Water use in the valley is predominately contains some tuff near the base. The maximum thick agricultural, and the increase in recent years has been ness of the Livermore gravel is about 4, 000 feet. due primarily to the transition from dry farming to irrigation. An estimated 80 percent of the total use is The floor of the Livermore Valley is covered by al for production of irrigated crops. The remaining 20 per luvial, lake, and swamp deposits of late Pleistocene cent is used by native vegetation and miscellaneous cul and Recent age. (See pi. 1.) These deposits consist of ture, and by domestic and municipal developments. gravel, sand, silt, and clay and constitute the primary aquifer of Livermore Valley. The thickness of alluvium An appreciable quantity of water has been exported averages about 350 feet, although a maximum thickness from the valley for municipal use. The San Francisco of nearly 700 feet is believed to be present in the Water Department, as successor to Spring Valley Water Pleasanton area. Company, pumps from a well field in the Pleasanton area at the lower end of Livermore Valley and exports The water supply of Livermore Valley is derived the water for municipal use. From 1897, when the well entirely from precipitation on the valley floor and from field was established, until 1934, the Pleasanton well surface and subsurface inflow from the tributary drain field was an important source of water supply to San age basin. The three main streams that traverse Francisco. However, since the completion of the Hetch Livermore Valley are Arroyo Del Valle, Arroyo Mocho, Hetchy aqueduct in 1934, the Pleasanton well field has and Arroyo las Positas. Outflow from the valley is been used only as a standby source. For the 28 years, concentrated in the Arroyo del Laguna which discharges 1918-45 the city of San Francisco pumped an average into Alameda Creek in the vicinity of Sunol. of 4, 900 acre-feet annually. The largest pumpage during this time was 14, 500 acre-feet in 1924. Deficient streamflow during the summer and autumn precludes diversion of adequate surface supplies, con For the 18-year period, 1915 33, the average annual sequently nearly all water used in Livermore Valley is pumpage in Livermore Valley was about 11, 300 acre- derived from ground water. feet (Smith, 1934). The total ground-water pumpage during water years 1949 and 1950 as estimated by the Livermore Valley contains two general hydrologic California Division of Water Resources is given in the areas: an area of free ground-water, and an area of tabulation on the following page. WATER RESOURCES OF THE SAN FRANCISCO BAY AREA Santa Clara Valley on the south. In this report the Pumpage iri acre-feet southern part of this plain, from San Leandro Creek on the north to the Santa Clara County line on the south, is 1949 1950 called the Alameda Plain. It is bounded on the east by the foothills of the Diablo Range and on the west by the 18,900 22, 200 tideland of San Francisco Bay, is about 25 miles long, 6,200 6, 200 and lies entirely within Alameda County. Export city of San Francisco... 6, 200 0 The part of the alluvial plain north of the Alameda 31, 300 28,400 Total...... Plain is almost completely urbanized. Imported water is supplied by the East Bay Municipal Utility District and ground-water use in the area is a small part of the According to estimates of the California Division of total use. Water Resources, Livermore Valley'has a mean annual recharge of about 14,400 acre-feet. Net draft (gross The late Quaternary alluvium composes the aquifer pumpage minus that portion returned to the ground- of primary importance; it consists of clay, silt, sand water body) of ground water in 1949 was 18,500 acre- and gravel. feet. The difference between these two figures, 4, 100 acre-feet, was the overdraft at that time. The Santa Clara formation is the aquifer of secondary importance in this plain area. It consists of medium to fine gravel commonly occuring in lenticular beds and Quality. Chemical quality data for ground water in sand and silt. This formation crops out along the foot the Livermore Valley are rather extensive, but ground hills, and underlies the alluvium of the plain. (See pi. 1.) water in the smaller valleys of SanRamon, Amador, and Sunol has not been as thoroughly sampled. Selected anal The Alameda plain is composed of coalescing alluvial yses of the ground water are presented in table 6. These fans; the chief ones, from north to south, are the San analyses show the ground water of Livermore Valley Leandro and San Lorenzo fans and the Niles cone. At and the smaller associated valleys to be of good quality least two separate water bodies can be differentiated in except for hardness and are suitable for most domestic most parts of the alluvial plain. The permeable sedi and irrigation use. In the eastern part of the Livermore ments that contain the water bodies are separated by Valley, waters are generally of poorer quality. Most clay and silt of low permeability. In the San Leandro of the water in these valleys is a calcium bicarbonate fan the upper 200 feet of sediments contain the upper type. For most of the water sampled in the Livermore water body, and all deeper sediments contain the lower Valley the dissolved solids ranged from 300 to 700 ppm water body. Most of the pumping here is'from the upper with an average of 466 ppm. Total hardness as calcium water body, which is replenished principally by perco carbonate ranged from 88 to 431 ppm with an average lation of San Leandro Creek on the apex of the fan. of 267 ppm, and the percent sodium ranged from 12 to .81 with an average of 35. In the San Lorenzo fan, -most irrigation, municipal, and industrial wells derive their water from the lower Several wells along the southern edge of the Liver- water body. Water in this body appears to be replen more Valley east of Pleasanton produced water of a ished, at least in part, by movement from the lower sodium bicarbonate type, and some wells northeast of water bodies in the adjacent San Leandro fan and Niles Livermore produced water high in sodium and chloride. cone. Several waters had above normal nitrate concentrations and many waters east of Livermore had boron concen In the Niles cone area, two principal water bodies trations in excess of 1. 0 ppm. have been differentiated, the base of the upper water body about 100 to 120 feet below ground surface, and the lower water body which extends from about 200 feet Sunol and Castro Valleys below surface to the base of the water-bearing sediments. An area of unconfined ground water near Niles is the Sunol and Castro Valleys are two small intermontane source of their replenishment. basins in Alameda County. Surface drainage from Livermore Valley passes through the northern end of Sunol Valley on its way to San Francisco Bay. Water-level fluctuations. The hydrographs of wells 4S/2W-26G1 and 4S/2W-4D2 (fig. 5) are considered Water-bearing formations in Sunol Valley are the representative of wells on the Alameda plain. Well same as in Livermore Valley, being late Quaternary 4S/2W-4D2, a municipal supply well for the city of alluvium underlain by the Livermore gravel of Clark Hayward, is 575 feet deep and draws from the lower (1930). Only one irrigation well was in use in Sunol water body. The altitude of the well is 13 feet. In 1939 Valley in 1950. This well yielded 200 to 250 gpm. the yield was 770 gpm. Well 4S/2W-26G1 is an irriga tion well of unknown depth, but probably taps a shallower The floor of Castro Valley is underlain by alluvium water body than does well 4S/2W-4D2. to a maximum depth of about 80 feet. The valley is mainly residential, and only a few domestic wells draw Pumpage. The annual gross pumpage during water water from the alluvial sediments. year 1949 was 46, 700 acre-feet. According to estimates of the California Division of Water Resources, the mean annual replenishment is about 30, 000 acre-feet; there Alameda Plain fore, with an overdraft of 16, 700 acre-feet, this basin is susceptible to salt water encroachment. Salt water An alluvial plain extends along the east side of San from San Francisco Bay began to seriously contaminate Francisco Bay from San Pablo Bay on the north to the upper water body of the Alameda plain about 1920. WATER SUPPLY OF SUBAREAS 27 By 1947 the landward movement of saline water reached Table 7. Maximum, minimum, average, median, the eastern edge of the clay that separates the upper monthly, and annual discharge of Alameda Creek water body from the lower water body. At that time near Niles, in mgd, water years 1925 53 salt water began to spill downward over the edge into the lower water body. By 1950, an area of about 600 acres Month Maximum Minimum Median Average in the lower aquifer was substantially contaminated by salt water. 23.6 0 . 1 2.02 November...... 350 0 1.2 15.8 Quality. The chemical quality data for the Alameda December...... 508 0 5.4 50.0 plain are mainly from the Niles cone area. The anal 1,602 . 14 23 116 yses of the sampled water show that the chloride per 1,571 .46 97 224 centage can be used as an approximate index of the salt 930 . 11 32 151 water contamination. April...... 700 .70 19 75.0 May...... 61. 7 .07 7.8 13. 7 Waters of poorer quality generally have a chloride June...... 29.8 0 2. 5 6. 33 content greater than 25 percent of the anion equivalents July...... 32.4 0 .9 4.29 and come from the upper water body or the contaminated 30. 7 0 .2 2. 57 parts of the lower water body. (See table 6.) In this 31.6 0 .06 2.46 class, dissolved solids range from 456 to 2, 360 ppm with an average of 941 ppm. Hardness as calcium car 255 .80 26 54.4 bonate ranges from 138 to 1, 670 ppm with an average of 667 ppm, and percent sodium ranges from 11 to 66 with an average of 24. The chloride content ranges The flow characteristics of Alameda Creek under from 76 to 1, 300 ppm with an average of 383 ppm. present conditions of development, storage in Calaveras Reservoir, ground-water diversions in Livermore Waters of good quality generally have a chloride con Valley and at Sunol filter galleries, and diversions from tent less than 25 percent of the anion equivalents and upper Alameda Creek, are shown by the flow-duration come from the uncontaminated parts of the lower water curves, figure 11, and the draft-storage curve, figure 12. body. (See table 6.) They are of moderate mineral The flow-duration curve shows the percentage of time content, and normally have less hardness than waters that a specified daily discharge in million gallons per from the upper water body. Some do have high per day or cubic feet per second has been equaled or ex centages of sodium which may make them unsuitable for ceeded. The draft-storage curve shows the net storage, irrigation. Dissolved solids range from 331 to 807 ppm required to maintain specific outflow rates at the gaging with an average of 425 ppm. Total hardness ranges station. Evaporation losses and dead storage must be from 22 to 449 ppm with an average of 225 ppm, and the added to the values shown on the curve to obtain the percent sodium ranges from 18 to 93 with an average storage required. of 40. The chloride concentration ranges from 10 to 85 ppm with an average of 39 ppm. Figure 13 shows a flood frequency curve for Alameda Creek near Niles for the period 1926 53, the period since completion of Calaveras Reservoir. This curve shows Surface Water the recurrence interval, under present conditions, for all floods over 800 cfs. Extension beyond the period of Alameda Creek record cannot be made with any degree of certainty; therefore the available records give little indication of Alameda Creek drains about 700 square miles with the maximum floods possible at the gaging station. altitudes ranging from sea level to almost 4,400 feet at Mt. Copernicus, just east of Mt. Hamilton. The drain Quality. Water in Alameda Creek near Niles is a age area above the gaging station near Niles is 633 calcium and magnesium bicarbonate type. The water square miles or 90 percent of the total area. also has a high mineral content during most of the year and is excessively hard. Analyses of samples collected The average annual precipitation in the Alameda once a month during the period October 1952 to September Creek basin ranges from about 12 to 15 inches in the 1953 are given in table 5. Plate 4 shows the variation Livermore Valley and from about 14 inches near the of some of the major constituents with streamflow. bay to about 28 inches in the vicinity of Mt. Hamilton. Analyses of sampled water containing maximum and minimum concentrations of dissolved solids are shown Discharge. Records of streamflow have been ob in figure 8. These values have been obtained from tained on Alameda Creek near Niles since 1916 and at analyses of sa'mples for the period January 1952 to other nearby points since 1891. (See figure 7.) In September 1953, and several samples collected prior 1925, Calaveras Reservoir (usable capacity, 69,900 acre- to this period. feet) was completed and water was stored for diversion to the city of San Francisco as part of the water supply Selected analyses of water from streams tributary to system. Alameda Creek are also given in table 5. The streams that drain the southern part of the basin are character The average discharge of Alameda Creek near Niles ized by high magnesium concentrations while the stream-1 for the water years 1925-53 is 54. 5 mgd (84.4 cfs). No that drain the northern part are characterized by high flow occurred for periods of a month or longer in 15 of sodium and high chloride concentrations. Usually the the 29 years and for shorter periods in 3 other years. flow from these tributaries is not sufficient to influence The maximum discharge was 18,500 cfs on Jan. 12, 1952. the quality of Alameda Creek to any great extent, but The monthly and annual maximum, minimum, average, occasionally during periods of low flow their effect can and median discharges are given in table 7. be noticed. DISCHARGE, IN CUBIC FEET PER SECOND to b> £» 01 u>£tbi 88$ '*' 2"- g s g o O H SJ. oSV WATER SUPPLY OF SUBAREAS 29 the maximum discharge observed was 2, 990 cfs on Feb. 27, 1940; however, the flood of Jan. 24, 1942, reached a stage 2. 6 feet higher than that of 1940 or a Avers geflow 54.6 nigd flow of about 4, 200 cfs. No flow occurs part of each year. The monthly and annual maximum, minimum and1 / average discharges are given in table 8. / / Table 8. Maximum, minimum, and average monthly and DAYMILLIONGALLONSPERINREGULATEDFLOW, annual discharge of San Lorenzo Creek at Hayward, 8So / water years 1947 53. So ii / PERFEETSECONDCUBICREGULATEDFLOW,IN / [Discharge in mgd] / Month Maximum Minimum Average / 0.56 0 0. 12 Water ; rears, 1 J26-53 19.5 0 3. 14 / 80.0 .08 20.2 / 147 .25 38. 1 40.5 .47 16.2 / 52. 3 2.68 20.5 15.8 2. 27 6.98 / 5.84 .33 2. 75 / June ...... 2.88 . 11 1. 08 July...... 1.36 .002 .47 3 100 200 300 401 .50 0 . 14 STORAGE, IN THOUSANDS OF ACRE-FEET . 17 0 .03 Figure 12. Draft-storage curveAlameda Creek near 25.7 .72 9. 18 NiLes. The flow characteristics of San Lorenzo Creek are shown by the flow-duration curve in figure 9. This curve has been adjusted to the period 1932 53. It may be used to determine the percentage of time that a spe o 15,000 cified daily discharge will be equaled or exceeded, as suming that the flow during the period 1932 53 was about normal and that the future will follow the same a pattern as in the past. a 10,000 Quality. Two chemical analyses of San Lorenzo Creek waters are given in table 5. The small amount of observed data on these streams indicate that the water is a calcium bicarbonate type of moderate mineral con tent. Both streams are very high in calcium and mag nesium hardness and chloride is prominent. RECURRENCE INTERVAL, IN YEARS San Leandro Creek Figure 13. Frequency of floods, Alameda Creek near San Leandro Creek enters San Francisco Bay through Niles, water years 1926-53. San Leandro Bay just south of Alameda. Chabot and Upper San Leandro Reservoirs (total usable capacity, 52, 700 acre-feet) were completed in 1892 and 1926 re San Lorenzo Creek spectively. Runoff records at Chabot Reservoir, since 1894, and at Upper San Leandro Reservoir, since 1925, Average annual precipitation in the San Lorenzo Creek are available in files of the East Bay Municipal Utility basin ranges from about 18 inches near San Francisco District. Chemical quality data for San Leandro Creek Bay to about 25 inches at the higher altitudes. Annual are given in table 5. runoff from the area above the gaging station has aver aged about 5 inches from 1946 to 1953. The drainage area upstream from the gaging station'at Hayward in Western Contra Costa County 38.0 square miles. The principal ground-water basins in western Contra Discharge. The average discharge of San Lorenzo Costa County are related to the topographic depression Creek at Hayward for the 8 years of'record, 1939-40, that centers around the city of Concord and contains 1946-53 is 10.1 mgd (15.7cfs). During the same period Ygnacio, Concord, and Clay ton Valleys. This area is 30 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA about 20 miles northeast of Oakland, and directly south His records show that the average depth of irrigation of Suisun Bay. The major streams of western Contra wells in Ygnacio Valley was about 250 feet. Wells 150 Costa County are Walnut, SanPablo, and Pinole Creeks. to 300 feet deep produce an average of 200 gpm. The deeper wells, 400 to 600 feet deep, produce from 350 to 500 gpm. In 1934, an estimated 3, 500 acre-feet of Ground Water water was being pumped annually from Ygnacio Valley. Clayton Valley is southeast of Concord and has a The present ground water pumping is limited to some maximum length of about 5 miles. Ygnacio Valley is industrial use, irrigation use of small amounts, and southwest of Clayton Valley and has a maximum length municipal supply pumped by California Water Service of about 7 miles. These two valleys merge with Concord Co. from 19 wells in four well fields in Concord Val Valley, to form an alluvial plain that extends to the Bay. ley. - These wells range in depth from about 100 to San Ramon Valley, a narrow elongated depression, ex 610 feet. Few wells are more than 300 feet deep. The tends as a connecting lowland link between Ygnacio yields of these wells range from about 100 to 150 gpm. Valley and Amador Valley. Amador Valley is the northwestern extension of Livermore Valley and is about 15 miles south of Ygnacio Valley. The Pittsburg Surface Water plain borders the tidal marshes where the Sacramento and San Joaquin Rivers join Suisun Bay. This alluvial Walnut Creek plain is about 5 miles east of the tidal portions of Concord Valley. At Walnut Creek the drainage area above the gaging station there is 78. 1 square miles and an additional The primary aquifer of this area is the Recent allu 20. 8 square miles is above the gaging station on Pine vium, composed of clay, gravel, and sand. The sec Creek at Concord. Altitude in the basin ranges from ondary aquifer consists primarily of the Pleistocene sea level to 3, 850 feet at Mt. Diablo. Pittsburg formation of Tolman, composed of continental clay, gravel and sand. This formation strongly re Discharge. Four gaging stations were established sembles the Santa Clara formation and the Livermore in the Walnut Creek basin the latter part of 1952 from gravel of Clark (1930). The terrace deposits along the which records for the 1953 water year were obtained. south shores of the bays, and the thin alluvium in the Discharge data for this 1 year of record are given in north part of San Ramon Valley are also considered as table 9. Lafayette Reservoir (capacity, 4,250 acre-feet) part of the secondary aquifer. is tributary to Walnut Creek through Lafayette Creek and is part of the East Bay Municipal Utility District's The thickness of these aquifers is not known; however, distribution system. the combined thickness of the alluvium and Pittsburg formation is at least 700 feet and possibly 1, 000 feet Quality. Chemical analyses of Walnut Creek and in the Ygnacio Valley (Poland, 1935.) San Ramon Creek waters are given in table 5. The small amount of data indicates that the streams have a mod This area, excluding San Ramon Valley, is served by erate concentration of dissolved solids but are very high East Bay Municipal Utility District, California Water in calcium and magnesium hardness. Service Co., and the Contra Costa Canal. Consequently the pumpage of ground water has decreased in the last 20 years. In the 1930's many industries in the Pitts San Pablo Creek burg area pumped ground water. The heavy pumpage created an overdraft which allowed saline waters to en San Pablo Creek, a stream of moderate size, enters croach in the ground water reservoirs near the bays. San Pablo Bay just north of Richmond. Streamflow Pumping has since decreased and most water now used records were obtained by the Geological Survey at two is surface water from the Contra Costa Canal and the points in 1918 19. San Pablo Reservoir (usable capac Sacramento River. Very little information is available ity, 41, 480 acre-feet) was built on San Pablo Creek in on present ground-water development in this area. 1920 and has received water from the Mokelumne Aqueduct since 1929 as part of the East Bay Municipal The only investigation of ground water in this area, Utility District's system. The District has obtained excluding the Pittsburg plain, was by Poland in 1935. runoff records at San Pablo Reservoir since 1917. Table 9. Maximum, minimum, and average flow of streams in Walnut Creek basin, water year 1953 Maximum Minimum Average Stream Discharge Discharge cfs Date cfs mgd Date cfs mgd San Ramon Creek at San Ramon...... 364 Dec. 7 No i low Many days 2.70 1.75 at Walnu t C reek ...... 2,200 Dec. 7 0.4 0.3 Sept. 28-30 11.0 7.11 Walnut Creek at Walnut Creek...... 5,810 Dec. 7 . 6 .4 Sept. 26 20.9 13.5 Pine Creek 548 Dec. 7 No flow Many days 2.53 1.63 WATER SUPPLY OF SUBAREAS 31 Pinole Creek Pumpage Pumpage Pinole Greek rises about 3 miles southwest of Martinez Year in acre- Year in acre- and flows westward and then northward until it enters feeta feeta San Pablo Bay at Pinole. The East Bay Municipal Utility District has obtained runoff records at their 1941...... 1,400 1947...... 7,600 proposed dam site since 1938. 1942...... 1,300 1948...... 7,000 1943...... 2, 100 1949...... 7,900 1944...... 3, 100 1950...... 6,300 Suisun-Fairfield Area 1945...... 4, 300 1951...... 4, 100 1946...... 5,700 The Suisun-Fairfield area consists of the low-lying alluvial plains and adjacent uplands north of SuisunBay. aPumpage for Green Valley is not included. This area comprises Suisun Valley, Green Valley, An overdraft is not evident in Green Valley or in the and several small unnamed valleys which widen south area east of Fairfield. The poor quality of water and ward where they merge with the tidal marshes along low permeability of the sediments east of Fairfield Suisun Bay. The area has a maximum width of about precludes any extensive ground-water development and 15 miles east-west and about 10 miles north-south. The there probably will be no overdraft in this part of the valley floor area is about 75 square miles. area. However, for the alluvial plain west of Fairfield the situation is different. Compared to levels measured in a few wells in 1918 22, the levels of 1951 ranged Ground Water from about the same to as much as 30 to 40 feet below those of 30 years ago. The ground-water depression The aquifer of primary importance in the Suisun- in the overdraft area is not large, being only about 2 or Fairfield area is the upper Pleistocene alluvium and 3 miles across; neither is the quantity of water large Recent alluvium. (See fig. 10.) These alluvial deposits that would be required to fill it. As of the spring of consist of silt and clay, gravel, and fine to coarse sand. 1950, the lowest part of the depression was about The maximum thickness is probably a little less than 20 feet below sea level li miles from the swamp. 300 feet. Although the depths to water are not as great as in The aquifer of secondary importance consists of the many ground-water basins, the close proximity of the Sonoma volcanics and the thin veneer of alluvium east tidal swamps along the south edge of the pumping de of Fairfield. This veneer of alluvium is probably less pression and the absence of any impermeable restrain than 50 feet thick. Water is available in small quanti ing member to keep out the salt water suggest that any ties and is of poor quality, high in boron, and toxic to long-continued depression of water levels below sea plants. The few stock and domestic wells are shallow level may cause deterioration of water quality along and produce only a few gallons per minute. The depth the southeastern part of the area. However, water to water in this area is generally less than 15 feet. levels nearer the swamp had little drawdown, indicating that the inland gradient at the edge of the swamp was quite flat at that time and danger of salt-water encroach Yield and depth of wells ment does not seem immediately serious. Ground-water supplies are limited almost entirely to the area of 35 square miles west of Fairfield. (See pi. 1.) Most wells in the area produce less than 300 gallons per minute. The depth of wells range from about Selected analyses of the ground water in the Suisun- 30 feet to nearly 1, 000 feet, but most wells are 100 to Fairfield area are presented in table 6. The water in 200 feet deep. this area is generally of the calcium and magnesium bicarbonate type; however, some water is high in sodium and chloride content. The total mineral content is Water-level fluctuations moderate to high. In the spring of 1950, depths to water in this area Water having high boron concentration is encountered ranged from less than 10 feet near the tidal swamp and at several places in the Suisun-Fairfield area. Wells in the upper valleys, to almost 60 feet in the heavily in Green Valley and on the western edge of the Suisun- pumped area southwest of Fairfield. The hydrograph Fairfield area usually produce waters that have accept of well 5N/2W-29R1 (fig. 6) is representative of wells able concentrations of boron. The areas north and east in the area west of Fairfield. This irrigation well is of Fairfield produce water that is very high in boron and 120 feet deep and its altitude is 46 feet. unsuitable for irrigation of most crops. The major part of the Suisun- Fairfield area is underlain by Cretaceous formations which are thought to be the source of the boron. Pumpage Total ground-water pumpage in the Suisun-Fairfield Surface Water area during years 1941 to 1951 is given in the following A group of streams called the Suisun Creek Group tabulation (Thomasson and others, 1956): enters Suisun Bay from the north in the vicinity of 32 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA Fairfield, Laurel, Ledgewood, Gordon Valley, Suisun, the upper 200 feet is cased out. The deepest wells in Green Valley Creeks are in this group. The total drain Napa Valley are in the Suscol area where the deepest age area is 348 square miles. Lakes Curry, Madigan, reported is 1,440 feet. Yields range from a few gal and Frey are part of the water supply sources for lons per minute to more than 400 gpm. Vallejo and have a total usable capacity ot 11,560 acre- feet. Water-level fluctuations Napa Valley Water levels in the primary aquifer range from near land surface to 30 feet below land surface. There has Napa Valley is a structural depression in the north been no significant long-range lowering of water levels. ern Coast Ranges that drains southward into San Pablo In the secondary aquifer the depth to water ranges from Bay. near land surface to 30 feet below land surface, but in some areas the depth to water is more than 100 feet. The central alluvial plain of Napa Valley is about In the area east of Napa the decline in water levels 32 miles long and ranges in width from less than 1 mile since 1918 has amounted generally to less than 30 feet. at the north end to about 4 miles near Napa. About In the Suscol area the depth to water ranges from 20 to 3 miles south of Napa the encroaching valley sides more than 100 feet below land surface. During the narrow the plain to less than one-half a mile and sep winter of 1949 50 water levels in some of these wells arate the main part of the valley from the tidal marsh were more than 50 feet below sea level. Water levels lands. Saline water from the bay can enter the aquifer in the Calistoga area ranged from slightly above land only along Napa River. surface to about 25 feet below. Hydrographs for 2 wells in Napa Valley are shown in Ground Water figure 6. Well 7N/5W-16B1, an irrigation well north of Yountville is about 330 feet deep and has an altitude The primary aquifer consists of unconsolidated al of 155 feet. Well 4N/4W-13E1 is a stock well 98 feet luvial deposits of late Pleistocene and Recent age. In deep in the low foothills along the lower part of Napa figure 10 the formations are shown as alluvium, ter Valley about 7 miles south of Napa. The altitude is race deposits and older alluvium. The secondary aqui 41 feet. fer consists of the Sonoma volcanics of Pliocene age and the Huichica formation of Pleistocene age. Pumpage Some parts of the Sonoma volcanics yield fairly large quantities of water but other parts are essentially non- The first available record of pumpage for Napa Val water bearing. Yields from the Huichica formation are ley is for a group of wells south of Napa, known as the generally poor. Within the Sonoma volcanics the ground Suscol wells. Between 1920 and 1937, these wells were water occurs in several more or less distinct bodies. pumped intermittently for extended periods, sometimes In Napa Valley the Sonoma volcanics contain three dis exceeding 2. 3 mgd (2, 600 acre-fe'et per year) mainly tinct ground-water bodies; one east of Napa, one in the for export to Vallejo and a sugar refinery near the bay Suscol area south of Napa, and one in the Calistoga at Crockett. These wells tap mainly the secondary area. aquifers. Table 10 shows pumpage in Napa Valley, from available records, for years ending March 31, 1946 50. Yield and depth of wells Table 10. Estimated ground-water pumpage in Napa In the primary aquifer the wells are generally less Valley, in acre-feet than 200 feet deep. The yields of the wells are depend ent upon the amount of gravel penetrated in each well Wells 1946 1947 1948 1949 1950 and range widely, from a few gallons per minute to about 400 gpm. 191 215 194 586 730 1,430 1,400 1,790 2, 160 2,900 In the secondary aquifer the depths to water, total 500 depths of wells, and well yields range widely from one Nonirrigation agricul 100 local area to another. The wells range in depth from ture wells, mainly 65 to 1,440 feet, but most wells are from 200 to 300 dairy. feet deep. Very few wells yield more than 400 gpm. Domestic and stock 1,000 wells. In the area east of Napa nearly all the wells tap con 30 fined water. The flow of most wells during the spring Flowing wells 300 range from a few gallons per minute to 24 gpm. The essentially non- two most productive wells flow 60 and 97 gpm. The beneficial use. wells range in depth from 65 to 700 feet, and most are more than 100 and less than 300 feet deep. The yields Total for 1950...... 5,560 range from a few gallons per minute to 830 gpm. The comparison of water levels in 82 wells measured In the Suscol area fresh water occurs in the tuff ace ous at different times during 1949 with water levels ob part of the Sonoma volcanics beneath the alluvial depos served in earlier years indicates no apparent significant its and along margins of the valley. Nearly all wells change since 1918, the first year for which there are are more than 400 feet deep and the brackish water in any known data. Thus for the valley as a whole there WATER SUPPLY OF SUBAREAS 33 appears to be no overdraft under present conditions. Table 11. Maximum, minimum, average, and median However, an area of chloride contamination exists in monthly and annual discharge of Napa River near Napa Valley south of the city of Napa. In 1952 this was St. Helena, in mgd, water years 1931-32, 1941-53 an area of local overdraft in that the water quality had deteriorated. The pumping draft subsequently has been Month Maximum Minimum Median Average reduced as water from Conn Reservoir has become available. This local overdraft probably will not con 2. 10 .06 .5 .67 tinue. 88.5 .06 2.6 11.8 310 . 67 65 132 498 4.98 97 175 534 5.84 97 145 251 15.8 84 98.9 Selected analyses of the ground waters in Napa Val April...... '... 316 5. 57 32 60.6 ley are presented in table 6. The analyses were se May...... 39.2 2.57 12 14.7 lected to show the quality from a single source, but 10.3 .52 4.2 4.89 many wells in the valley produce water from several July...... 4.95 .09 1.6 1.94 water-bearing zones. The ground water is generally 2.86 .06 .8 .96 of suitable quality, but locally contamination may be 2.01 .06 .5 .56 encountered. This is particularly true of the southern part of the valley where saline bay waters encroach in 136 4.52 44 53.6 the water-bearing zones of these tidal marshlands. The primary contaminants in these areas are sodium chloride, boron, and nitrate. The source of boron is unknown. The occurrence of nitrate is attributed to The draft-storage curve shows the net storage re the ancient "tule mud. " quired to maintain specific outflow rates at the gaging station. Evaporation losses and dead storage must be Water from both the younger and older alluvium in added to the values shown in the curve to obtain the the northern part of the valley is a calcium bicarbonate storage required. type with moderate mineral content. Some high boron and chloride is. encountered locally. Some lenses of The flood-frequency curve for the Napa River near freshwater are over layers of saline water and in some St. Helena for the period 1930-32, 1940-53 (fig. 16) areas water of good quality is below these saline waters. shows the recurrence interval for all floods greater 'More fresh water is available during periods of heavy than 2, 300 cfs. Extension of the curve cannot be made precipitation, but this is depleted rapidly under heavy with any degree of certainty; therefore the available pumping. records give little indication of the maximum floods possible at the gaging station. The water from the Sonoma volcanics and Huichica formation is generally of poorer quality than water from Development of storage in the Napa River basin has the alluvium. Total mineral and sodium content are been mainly on the tributaries. Conn Reservoir or usually higher than in water from the alluvium. Some Lake Hennessey (capacity, 31, 000 acre-feet) was com wells produce water high in boron. pleted in 1948 by the city of Napa; however, some water has been stored since December 1945. Rector Reservoir (capacity, 4, 400 acre-feet) was finished in 1946 and Surface Water furnishes water for nearby State institutions. Milliken Reservoir (capacity, 2, 000 acre-feet) is a part of the Napa River water-supply system for Napa. Many small reservoirs have a combined capacity of about 1, 600 acre-feet. The drainage area above the gaging station near St. Helena is 81. 3 square miles. Two major tributaries, Quality. The water of the Napa River is a calcium Conn and Dry Creeks, are also gaged. (See fig. 7.) bicarbonate type low in dissolved solids. Chemical The total drainage area above these three gages is analyses of Napa River water near St. Helena collected 151 square miles or 36 percent of the 417 square miles at monthly intervals during the period October 1952 to in the Napa River basin. September 1953 are given in table 5. Plate 4 shows that the total concentration varies with streamflow but Average annual precipitation in the Napa River basin that the relative proportions of the ions in solution re ranges from about 18 inches near San Pablo Bay to main generally constant. The waters are comparatively 70 inches on Mt. St. Helena at altitude 4, 344 feet. An soft at times of high flow. Analyses of sampled water nual runoff averages about 8 inches for the 15 years of containing maximum and minimum concentrations of record. dissolved solids are shown in figure 8. Discharge. The average discharge of Napa River near St. Helena for the 15 years of record (water years Sonoma Valley 1931-32, 1941-53) is 53. 6 mgd (82. 9 cfs). No flow oc curred on 14 days in 1947 and on 1 day in 1949; the Sonoma Valley, north of San Pablo Bay, is a roughly maximum discharge was 11,800 cfs on Feb. 6, 1942. triangular alluvial-filled structural depression, about The monthly and annual maximum, minimum, average, 8 miles long and 6 miles wide at the southern margin. and median discharges are given in table 11. The southern part of the alluvial plain grades almost imperceptibly into tidal marshlands of San Pablo Bay. The flow characteristics of the Napa River are Sonoma Valley is drained chiefly by Sonoma Creek which shown by the flow-duration curves, figure 14, and the heads on the west side of the Mayacmas Mountains draft-storage curve, figure 15. bordering the valley on the east. 34 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA 8000 6000 5000 4000 > 3000 \ s 2000 \ , \X \ 1000 \ N^- y 800 X \ / \ N, 600 I/ s \ " Extended to period Oct sber] 931 \ \ 500 I to September ] 953 \ x^ 400 ^V N 300 \ \ 200 Aj \ v \ \ 1941 i \ Year of highest average discharge g 100 \ X- Vv °- 80 -V ^v- Figure 14. Duration curves of daily flow, Napa River near St. Helena. WATER SUPPLY OF SUBAREAS 35 water, in the older formations is generally confined or AVI rage fit w, Dec 1929 to Septl ?32, 31, Smgd 7 partially confined. / Water-level fluctuations 8ft5o / The water levels in the unconfined aquifers generally DAYPERGALLONSINMILLIONFLOW,REGULATED SECONDFEETPERFLOW,INCUBICREGULATED range from 5 to 25 feet below land surface. The average 85 / depth to water is about 15 feet; the greatest about 45 feet. The depth to the water in the confined aquifers is gen X erally somewhat less. The seasonal fluctuations of water levels for both primary and secondary aquifers Y is about 20 feet. Figure 6 shows the hydrograph for / well 5N/SW-28N1 in Sonoma Valley. This well is 11 feet . / above sea level and 130 feet deep. The period of record of water levels in Sonoma Valley / is not long enough to observe significant changes. How ever, during the summer static water levels on the alluvial plain near the salt marshes are below sea level. / During summer pumping,the chloride content of the 3 10 20 30 40 5 water indicates saline-water encroachment. Informaticn STORAGE, IN THOUSANDS OF ACRE-FEET at hand seems to indicate the salt water is diluted by recharge from winter rains. Continued development of Figure 15. Draft-storage curve, Napa River near this area, if it involves lowering water levels below sea St. Helena. level and holding them there more than a season or two, 12,000 may lead to serious saline-water encroachment. Yield and depth of wells 10,000 The wells in the unconfined primary aquifer are gen erally less than 200 feet deep, with yields ranging widely from just a few gallons per minute to more than 8 400 gpm. The wells in the secondary aquifer are gen 8000 erally deeper with essentially the same wide range in yields, but with lower average yields. 9 6000 Pumpage The ground-water pumpage prior to 1945 is estimated at less than 800 acre-feet annually, divided about equally 4000 between irrigation and domestic uses. The following tabulation shows the annual pumpage in acre-feet in the Sonoma Valley for the 5 years 1946 50 with years end ing March 31: 2000 Pumpage in acre-feet per year Year Large Domestic Total wells a wells a 1.0 10 100 RECURRENCE INTERVAL, IN YEARS 1946...... 490 300 790 910 400 1,310 Figure 16. Frequency of floods, Napa River near 1947...... 1948...... 970 400 1,370 St. Helena, 1930-32, 1940-53. 1949...... 1,300 500 1,800 1950...... 1,900 500 2,400 Ground Water aUse from domestic wells was estimated and large wells are those pumped by a 5-horsepower or larger motor. The water-bearing formations of Sonoma Valley are essentially the same as those of Napa Valley. The primary aquifer consists of unconsolidated alluvial de posits of late Pleistocene and Recent age. The second ary aquifer consists of the Sonoma volcanics of Pliocene Selected analyses of the ground water in Sonoma Val age, and the Huichica and Glen Ellen formations, parts ley are listed in table 6. Many wells produce water of which are essentially non-water-bearing and parts from several strata which contain water of different of which yield small to moderate quantities of water. quality. The analyses selected show the quality from a Water in the primary aquifer is essentially unconfined; single source whenever possible. 36 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA The water of the unconfined younger and older allu Pliocene and Pleistocene(?) age. It is water yielding vium is a calcium bicarbonate water of moderate min in part and is important in some areas, but does not eral content. Occasionally high boron concentrations form an appreciable portion of the ground-water reser are encountered which makes the water unsuitable for voir. irrigation. In the southern part of the valley where water levels fall below sea level, brackish waters are Yield and depth of wells encountered; some lenses of fresh water are found, but yields are small. This area of saline contamination is In the southern part of Petaluma Valley the depth of not constant, but increases and decreases according wells ranges widely from about 15 feet to more than to the balance between the amount of recharge from 500 feet, and most of the wells are between 100 to surface precipitation and the amount of pumping draft. 200 feet deep. The yield of these wells is generally During the rainy months recharge is heavy and the less than 30 gpm. In the northern part of Petaluma saline water moves south. Under heavy pumping dur Valley the depth of domestic wells in the primary aquifer ing the irrigation season, this saline water moves north range from about 60 to 150 feet; wells in the secondary and again contaminates the ground water. aquifer are generally deeper. The wells with higher yields, 150 to 300 gpm, range from about 250 to 600 feet Water from the Huichica and Glen Ellen formations and tap both aquifers. The highest yield reported is is generally of suitable quality. High chlorides are about 650 gpm. In Novato Valley the depth of most of encountered locally in the Huichica formation; the Glen the wells ranges from about 30 to 60 feet; the yield is Ellen formation may locally produce water of high boron about 25 to 40 gpm. content. High boron concentration in water from some wells tapping the alluvium is thought to originate in the Glen Ellen formation. Water-level fluctuations Water from the Sonoma volcanic s is generally of good In the area of greatest pumpage in northern Petaluma quality but locally high chloride concentrations are en Valley, water levels in the spring are mostly between countered. This may be due to unflushed connate waters 10 and 25 feet below land surface; autumn water levels in the formation. are between about 15 and 40 feet below land surface. The hydrograph for well 5N/7W-35K1 in Petaluma Surface Water Valley is shown on figure 6. This is an irrigation well 78 feet deep. The altitude is 19 feet. Sonoma Creek drains into San Pablo Bay. The State of California maintains two off-stream reservoirs with Under present conditions in Petaluma Valley, there a combined capacity of 550 acre-feet to supply water to seems to be no substantial excess of withdrawals over a State institution. Average precipitation ranges from replenishment. However, it should be noted that in 20 to 40 inches between the mouth and the headwaters most of the area north and east of Petaluma where most of Sonoma Creek, for which streamflow records have of the draft in Petaluma Valley is concentrated, water not been collected. levels in the spring of 1951 were from 5 to 20 feet above sea level; and throughout the valley most summer pump ing levels were below sea level. Probably saline water Petaluma Valley from the bay and sloughs would intrude the aquifers if water levels were held at substantially lower levels for Petaluma Valley, in Sonoma and Marin Counties a few years. northwest of San Pablo Bay, is an alluvial-filled valley, about 16 miles long and 2 to 3 miles wide. It is in a northwest-trending structural depression bordered on Pumpage the east and west by mountains higher than 2, 000 feet. To the north, Petaluma Valley is separated from Santa Most of the ground-water draft is in the nor them part Rosa Valley by a low divide. The greater part of the of the valley. Irrigation has developed largely since 25 square miles of lower Petaluma Valley is at or 1900. Ten irrigation wells were in use in 1949 and 14 slightly below sea level. Much of this land has been in 1952. The following tabulation shows ground-water reclaimed by drainage ditches and levees. pumpage in acre-feet in Petaluma Valley during the period 1945 to 1949. Small Novato Valley adjoins Petaluma Valley on the south and borders San Pablo Bay. Novato Valley and the bayward extension of its coastal plain has a total Use 1945 1946 1947 1948 1949 length of about 10 miles and a width of less than 2 miles. Only the upstream part, about 4 square miles, has been Public supply for Petaluma 420 500 720 660 760 developed for agriculture and urban use. The rest of and Penngrove. the area is unreclaimed tidal marshland. 140 130 110 210 250 80 130 140 130 120 Domestic, stock and 620 650 680 700 720 Ground Water other. The primary aquifer is composed of unconsolidated Yearly total...... 1,260 1,410 1,650 1,700 1,850 alluvium of Quaternary age. The secondary aquifer consists of the Tolay volcanics of Morse and Bailey (1935), the Sonoma volcanics, and the Petaluma forma In Novato Valley the total annual ground-water pump- tion, all of Pliocene age, and the Merced formation of age is probably less than 400 acre-feet. WATER SUPPLY OF SUBAREAS 37 Table 12. Maximum, minimum, and average monthly and annual discharge of Petaluma Creek near Sufficient chemical quality data are not available to Petaluma, in mgd, water years 1949 53 completely define the quality of the ground water in the several water-bearing zones in the Petaluma Valley. Month Maximum Minimum Average Although the analyses listed in table 6 are considered to be representative of the water from the various for 0.03 0 0.006 mations, they should be used with reservations when 20. 3 6 4.26 attempting to evaluate the over-all quality of the spe 80.8 .04 39.9 cific source. Many wells produce water from more 131 . 61 58.7 than a single aquifer and variations in artesian head 46. 3 1.82 25.7 can cause the water from different water-bearing zones TV/f r\ y» f-t V) 47.8 2.71 22.4 to intermix. 7. 37 .45 2.33 . 58 . 11 .26 The water from the younger and older alluvium and . 15 0 .04 the Merced formation is generally of good quality. It July...... 0 0 0 is of the calcium bicarbonate type tending toward a 0 0 0 sodium bicarbonate type with increasing depth. Total 0 0 0 mineral concentration generally ranges from 250 to 500 ppm. Locally some wells produce water of poor 21. 3 4. 61 12.8 quality. Salt water contamination is found in the south ern part of the valley where saline bay waters intrude the aquifers of the tidal marshlands. In some areas the contamination may be caused by unflushed connate Novato Creek waters of ancient seas. Novato Creek above the gaging station near Novato The water from the Petaluma formation is usually of drains an area of 17. 2 square miles, almost the entire poorer quality than water from the alluvium and the basin. Altitudes in the drainage basin range from sea Merced formation. It is generally a sodium chloride level to about 1, 600 feet. type water of high mineral content. Some wells pro duce waters high in boron which makes them unsuitable The average annual precipitation in the Novato Creek for irrigation purposes. In general, waters with high basin ranges from about 20 inches at the mouth of s-odium and chloride content and high total concentra Novato Creek to about 35 inches on the higher hills tion are unsuitable for irrigation though such waters south of the creek. Annual runoff has averaged about have been used with success under unusually favorable 9 inches for the period 1946 53. conditions of crop growth. Discharge. The average discharge of Novato Creek near Novato for the 7 water years, 1947 53, is 6.85 mgd Surface Water (10. 6 cfs). In 1951, the North Marin Municipal Water District built Novato Creek Reservoir (capacity, Petaluma Creek 1, 700 acre-feet). The estimated safe yield of this de velopment is about 900 acre-feet per year. The maxi The drainage area above the gaging station near mum discharge was 1, 130 cfs, Dec. 3, 1950, and the Petaluma is 29. 6 square miles, and elevations range stream is dry for several months each year. The from sea level to about 2, 300 feet. monthly and annual maximum, average, and minimum discharges are shown in table 13. The average annual precipitation in the Petaluma Creek basin varies from about 20 inches on the Table 13. Maximum, minimum, and average monthly tidal flats to about 25 inches on the hills. An and annual discharge of Novato Creek near Novato, nual runoff averaged about 9 inches for the in mgd, water years 1947 53 period 194&-53. Month Maximum Minimum Average Discharge. The average discharge of Petaluma Creek near Petaluma for water years 1949 53 is October...... 0 0 0 12.8 mgd (19.8 cfs). During this period the max 8.72 0 1.26 imum flow was 1, 360 cfs on Dec. 3, 1950, and December...... 55.6 0 15.7 periods of no flow have occurred for several January...... 76.9 . 17 27.2 months each year. The monthly and annual max 36.8 .23 16.4 imum, average, and minimum discharges are shown 57.8 2.46 n Q in table 12. 6.31 1.31 3. 19 May...... 1. 57 .48 .78 Flow characteristics of Petaluma Creek are shown June ...... 35 0 . 17 by the flow-duration curve (fig. 17.) July...... 12 0 .03 August ...... 0 0 0 Quality. A single analysis of Petaluma Creek 0 0 0 water, table 5, shows it to be of'the calcium and magnesium bicarbonate type of moderate mineral Annual...... 12.6 .92 6.85 content and hardness. 38 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA ... ,,,,.,.,,,..r_ ...... 800 600 500 400 t 300 \ s 200 V \ N 100 \ .\ \v 80 \ V \ N> \ > 60 \ 50 -\\\\ , \\ 40 1 ' V \\> 30 \ \\ 20 \ Note : Rec ordse xtende d to period V* Oc tober 1931 to Sep tember 1 353 \\ by statistical rnethods 10 \\ ^ 8 \ ^p \ 6 \\ \ \\ \ 5 \ 4 \ -S \ 3 ?F N- ^ 2 ^ \ \ T V --"Co rteM adera C;reek 1.0 \V \ .8 \ .6 A .5 V \ V .4 \ ^r- \ \ t .3 \ \ \ .2 Petalum a Greet ^\ ^ \ \ ^ Novato Cree* \ V \ .1 \ .08 5 \ k > \ .06 .05 .04 .03 .02 01 0.01 0.050.1 0.2 0.5 12 5 10 20 30 40 50 60 70 80 90 95 98 99 99.5 99.8 PERCENT OF TIME DISCHARGE EQUALED OR EXCEEDED THAT SHOWN Figure 17. Duration curves of daily flow, Petaluma, Novata, and Corte Madera Creeks. IMPORTED WATER 39 The flow characteristics of Novato Creek are shown serve are shown in plate 5. At present the San Fran by the flow-duration curve, figure 17. cisco Bay Area itself is an area of deficient water supply; so any increase in the demand for water must Quality. The water of Novato Creek is a calcium be met by importations from sources outside the area. and magnesium bicarbonate type of low mineral content Figure 18 shows the importations of water to the and of fairly good quality. (See table 5.) San Francisco Bay Area for each of the four major systems. Southern Marin County Hetch Hetchy System Two streams, Corte Madera Creek and Arroyo Nicasio in southern Marin County, have been gaged. The rocks In 1913, after 12 years of litigation, the city of San of southern Marin County are essentially non-water Francisco was granted authorization under the terms bearing and only minor amounts of ground water are of the "Raker Act" to construct and operate the Hetch pumped. Hetchy system. This authorization was required be cause the major reservoirs are in Yosemite National Park on the Tuolumne River and its tributaries. Surface Water Storage in Lake Eleanor (usable capacity, 26, 100 Corte Madera Creek acre-feet) began in 1918. O'Shaughnessy Dam, which forms the Hetch Hetchy Reservoir, was completed in' The drainage area of Corte Madera Creek above the 1923. It was raised 85. 5 feet in 1937 and had drum gaging station at Ross, which is just above tide water, gates installed on the spillway in 1949 making its pres is 18. 3 square miles. Altitudes range from sea level ent usable capacity, 360, 400 acre-feet. Hetch Hetchy to 2, 600 feet. water first reached the San Francisco area in 1934. The Cherry Valley Reservoir, under construction in Corte Madera Creek has been gaged only since Feb 1954, will be capable of storing 268, 000 acre-feet, ruary 1951. The average discharge for the water year part of which will be available for importation to San 1952 was 31. 1 mgd (48. 1 cfs) and that for 1953 was Francisco. The capacity of the Hetch Hetchy system 18. 3 mgd (20. 3 cfs). The maximum discharge was at present is about 160 mgd or 180,000 acre-feet per 3, 300 cfs on Dec. 3, 1951, and a minimum flow of year; however, the capacity can be increased to about 0. 06 mgd (0. 1 cfs) has been reached at times from 400 mgd or 450, 000 acre-feet per year by construction August to November. of additional storage facilities, pipe lines, and a second Coast Range tunnel. The water is brought by gravity Flow characteristics of Corte Madera Creek are to Crystal Springs Reservoir in San Mateo County by shown by the flow-duration curve (fig. 17). means of the Hetch Hetchy Aqueduct and Bay Crossing lines. The Marin Municipal Water District operates Phoenix Lake (total capacity, 612 acre-feet) on Phoenix Gulch, The Hetch Hetchy system supplies soft mountain a tributary of Corte Madera Creek, as part of the mu water, very low in dissolved solids which consist prin nicipal supply for the urban areas. cipally of calcium and magnesium bicarbonate. Four analyses made during a 4-year period beginning Arroyo Nicasio Arroyo Nicasio above the gaging station nearPt. Reyes Station drains an area of 36. 2 square miles which for all practical purposes is the total drainage area of the basin. Altitudes range from about 50 feet at the mouth to about 1, 850 feet near the headwaters. The average annual precipitation in the Arroyo Nicasio basin is about 30 to 35 inches. The gaging station near the mouth of Arroyo Nicasio has been in operation only since July 1953. The record from July 25 to Sept. 30, 1953, shows 55 days with a flow of 0. 06 mgd (0. 1 cfs) and 13 days with no flow, 8 of which were consecutive. IMPORTED WATER Four major systems have been constructed to import water to the San Francisco Bay Area. These are the Hetch Hetchy system of the city of San Francisco, the Mokelumne system of the East Bay Municipal Utility District, the Contra Costa Canal in northern Contra Costa County, and the Cache Slough system of the city of Vallejo. These systems and the areas which they Figure 18. Water importation, water years 1929 53. 40 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA July'1, 1949, indicate dissolved solids vary from 27 0 « « 13 ~ oooooooooooo «w o «, o u to 36 ppm, and hardness varies from 10 to 22 ppm o ^ a S § £ (table 16). 8. g § -g * « W y ^, R ^^g^^S5555SS Mokelumne System The East Bay Municipal Utility District was formed oooooooooooo in 1923, construction of the Mokelumne system started > W ITS "o 3 CM in 1925, and water was first delivered to the District's 1 W O distribution system in June 1929. Pardee Reservoir in in CM i-H 1 (usable capacity 194, 100 acre-feet) on the Mokelumne Q River near Jackson, is the source of the system's mco^LnocM^cM-^cMN^ CM water supply. Parallel aqueducts 93 miles long and "cB O CO CM 0 £ h « O H two pumping plants convey the water to the District's O 15 i 5, rH distribution system. The present capacity of the system H is 156 mgd or about 175,000 acre-feetper year. Planned CM T-l T-l T-l 05 CL) PQ enlargement of the pumping plants will increase the JH u 'c ~ en 1 1 capacity to about 2GO mgd or 224,000 acre-feet per CL) 0) _^ OOOOCM'^'-'OOCOCO^'COO year. 3 CB -?* "S. T-l CM T-l rH (U "s 5£. The Mokelumne River supply is soft mountain water, o a X oocooooooomcoco low in dissolved solids and individual constituents ?-, CD i -2 ?; £ C £H CB f^ a (chlorides, and sulfates). Hardness is generally about CO o 20 ppm and varies little with time (tables 19 and 20). £ CJ J2O U*-* w "cfl CB OJOOtOCOOlttlCOOOOOCO C a TO In co "CB O CD u c U TB Contra Costa Canal U a 03 w « j§ £ CB W 1 o^^^co^o^o^c-co Another major import to the San Francisco Bay Area O JH CB comes from the Contra Costa Canal which was built by U a ... - -» - w CO C "5 .2 SS o the United States Bureau of Reclamation as a part of Lt l-l DH w u the Central Valley Project. The canal, which was com O "3 SSS32S5SSgSS "HJH pleted in 1940, diverts from Rock Slough in the Sacra U "8 w S|I o mento-San Joaquin Delta. Four pumping plants lift the CD^ C) water 115 feet into the 48-mile concrete-lined canal I CO CM iH which terminates at Martinez Reservoir. The capacity IB o c a -55 "5 rH HO 3 >^ of the canal is 226 mgd (350 cfs) at the intake, and is (T rt 'tn £ reduced to 174 mgd (269 cfs) by the time it enters the g San Francisco Bay Area. In 1954 pumping plant no. 1 CB i g ^ O * .2 u had an installed capacity of 200 mgd (310 cfs). The 14.Chemicae CD 05 water is distributed by the Contra Costa County Water JH c o "tj "t^^t^"-*-* * " u CB PUBLIC WATER SUPPLY SYSTEMS 41 m IN 0 tf U3 0 Cache Slough System 3 CO rH 4_,s'l-oi 73 'G The rapid growth of Vallejo and vicinity during World s-sS 9 rtB ia War II caused a water shortage; so a connection was fc -S 8 made between the Vallejo system and that of the East m CO 0 r- IO O S'O 5 00 CD OS o Bay Municipal Utility District. Most of the supply was furnished by the latter agency until April 1953, when the contract was terminated. The city of Vallejo had, : a. by this time, completed its Cache Slough system. 0 10 c cJw jt! CD The Cache Slough system pumps water from Cache a- I S OC CO CI U3 -^f -^ IN IN -^H Slough, a tributary to the Sacramento-San Joaquin Delta § >- !0- CD r- 3% near Rio Vista, and conveys the water to a treatment 8 a-stgs a CT r- ^ c- plant just north of Vallejo. The present transmission 2 capacity is about 21 mgd or 23> 500 acre-feet per year. ; s-* 1 j i ! i j Raw Cache Slough water is of good chemical quality IN 03 IN ! 0 IN IN ^ and generally similar to Sacramento River water when 0 uJ : IN CM rH rH u-. rH streams on the west side of the Central Valley are not || || flowing. The analysis of a sample taken May 14, 1953 rH * C rH M i- U3 O C U3 IT ^f CD rH IO C rH CO tf2 r- 05-* rH IN (table 22), indicates the water is a calcium and mag {f| rH nesium bicarbonate type. Dissolved solids for this sample amounted to 248 ppm. Partial analyses indicate CO en -d? 0 OS *O 0 0 large municipal type districts or legal entities are re 10 So quired to provide sufficient financial backing. In the 00 CD Physical data for several public water systems are ||_a summarized in table 15. The information presented o was furnished by the agencies listed. 42 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA San Francisco Water Department cipal Santa Clara Valley cities or communities north of Santa Clara and to southern Alameda County cities and The San Francisco Water Department obtains its and communities from Hayward south. Distribution water from local sources and from the Sierra Nevada. systems in these communities are owned by individual These sources can be divided into three units; the cities, public utility companies, water districts, or Peninsula system, the Alameda system, and the Hetch private individuals. Hetchy system. Under the Hetch Hetchy system, water is obtained from catchment areas above the Hetch Hetchy The waters of the San Francisco Water Department Reservoir on the Toulumne River and Lake Eleanor on at the source range from soft mountain water to rela Eleanor Creek. The Alameda system receives its tively hard ground water. (See table 16. ) The waters water principally from Calaveras Reservoir which im of very low mineral content frorr the Hetch Hetchy pounds the runoff from Calaveras Creek watershed and system are mixed with the harder waters of larger from the upper Alameda Creek diversion. Two ground- mineral content to give a water that is moderately water sources, the filter galleries at Sunol and the soft and relatively low in dissolved solids. The waters Pleasanton wells in the Livermore Valley, furnished from all five sources can be classed as a calcium and supplementary supplies. The Peninsula system obtains magnesium bicarbonate type. water from Pilarcitos, San Andreas and Crystal Springs Reservoirs which are replenished by local runoff and Typical analyses and range in several important chem water from the Alameda and Hetch Hetchy sources. ical constituents in water delivered to consumers are shown in table 17. Variations in hardness are shown in The storage capacities of the reservoirs in million figure 19. Water delivered by Crystal Springs lines and gallons are as follows: San Andreas lines varied little in quality during the 4 years but that delivered by the Bay Crossing lines Hetch Hetchy...... 117,450 varied considerably. This variation is the result of Lake Eleanor...... 8,500 changes in the source of supply. For example, during Calaveras...... 31, 580 the 1952 53 year, the Bay Crossing lines carried: A Crystal Springs...... 22, 580 Hetch Hetchy-Calveras mixture for the period of July 1 San Andreas...... 6, 190 to August 13, October 27 to January 11, and April 5 to Pilarcitos...... 1,010 June 30; Calaveras water only, for the period August 13 Cherry3...... 87,300 to October 27; and Hetch Hetchy water only, or a Hetch Total...... 274, 610 Hetchy-ground water mixture, during the remainder of the year. a Cherry Reservoir is at present (1954) under con struction. The water served to consumers complied with the bacteriological standards established by the U. S. Water deliveries for San Francisco and suburban Public Health Service and objectionable tastes and areas for the fiscal years, 1949-50 through 1952-53, odors were absent. were as follows: San Jose Water Works Water Deliveries The San Jose Water Works obtains about 40 percent Year Total Average of its supply from surface water and 60 percent from Million gallons mgd wells in and near San Jose. The San Jose Water Works has authority to take 9, 000 acre-feet per year from 1949-50...... 37, 594 102. 7 Los Gatos Creek and 1. 29 mgd (1. 96 cfs) by direct di 1950-51...... 38, 751 105. 8 version from Saratoga Creek. The output of water for 1951-52...... 39,946 109. 1 the entire system during 1953 averaged 25 mgd. The 1952-53...... J 43,230 118.4 maximum daily output was 48.4 million gallons and the minimum daily output was 9. 0 million gallons. The San Slightly more than half of the 1952 53 deliveries were Jose Water Works serves about 220, 000 persons. obtained from the Hetch Hetchy system. During pre ceding years, the proportion from the Hetch Hetchy Treatment of surface water consists of aeration, sed system was greater; in 1950 51 it was more than twice imentation, ammoniation, and chlorination. Some wells the amount obtained from local sources. are chlorinated. Raw water storage reservoirs are treated with copper sulfate to control algae. Water distributed by the San Francisco Water De partment requires some treatment. This includes chlo- Typical mineral analyses of Los Gatos Creek samples rination of all supplies, addition of lime to the soft taken between December 1951 and May 1953, show a Hetch Hetchy water for corrosion control, and copper specific conductance range of 216 to 540 micromhos, sulfate treatment of local storage and impounding res total hardness of 60 to 250 ppm as calcium carbonate, ervoirs to control algae activity. Fluoridation of ap and turbidity of 2 to 900 ppm. Table 18 gives annual proximately 50 percent of the water supplied to San composite analyses of San Jose water for the period Francisco began August 25, 1952. 1946 through 1953. The composite is made up of many samples taken during each year. These analyses indi The San Francisco Water Department furnishes water cate that the water is acalcium and magnesium bicar either wholly or in part to all cities and towns in San bonate type and is comparatively uniform in concentra Mateo County and furnishes supplemental water to prin tion and composition throughout the year. Table 16. Chemical analyses of San Francisco Water Department water [Analyses by San Francisco Water Department; results in parts per million except as indicated] Specific Alka Fiscal Alumi Manga Cal Magne Bicar Car Chlo Fluo- Total conduct year Silica Iron Sodium Sulfate Nitrate Boron Source num nese cium sium bonate bonate ride ride Dissolved hardness linity ance PH (July 1- (Si02) (Fe) (Na) (SO*) (NO.) (B) (micro- (Al) (Mn) (Ca) (Ms) (HCOs) (CO.) (F) solids as as June 30) CCVD CaCO, CaCOs mhos at 25*C) UNTREATED Hetch Hetchy at Alameda E. Portal...... 1949-50 13.0 0.01 1.01 0.0 2.4 1.0 1.2 10 0^0 3.2 1 0.08 0.01 0.1 27 10 8 18 6.9 1950-51 3.0 .06 .04 .0 6.4 1.5 4.1 23 £0 2.8 5 .06 .03 .15 36 22 21 63 9.1 1951-52 3.0 .06 .04 .0 6.4 1.5 4.1 23 2.0 2.5 5 .05 .03 .15 36 22 21 63 9.1 1952-53 5.0 .02 .00 .0 5.5 .5 5.1 15.9 1.8 3.6 4 .15 .01 .12 34 16 17 54 9.2 1949-50 7.5 .03 .04 .0 21.5 7.8 6.8 98 .0 10. u' 5 .10 .15 .15 108 86 80 192 7'» 7' 1950-51 7.0 .03 .02 .0 25.2 8.8 8.8 105 .0 17.2 7 .10 .20 .15 128 99 86 225 7.7 1951-52 7.0 .03 .02 .0 25.2 8.8 8.8 105 .0 17.2 7 .10 .20 .15 128 99 86 225 7.7 1952-53 8.2 .01 .00 .0 26.3 8.4 9.8 107 .0 16.6 8 .20 .01 .09 130 100 88 213 7.8 1949-50 15.0 .03 .03 .0 51.4 25.4 30.1 269 .0 39.5 28 .05 .50 .18 321 233 220 548 7'.V Q 1950-51 15.0 .03 .03 .0 51.4 25.4 30.1 269 .0 39.5 28 .05 .50 .18 321 233 220 548 7.9 1951-52 15.0 .03 .03 .0 51.4 25.4 30.1 269 .0 39.5 28 .05 .50 .18 321 233 220 548 7.9 ^ 1952-53 11.6 .01 .00 .0 45.9 21.9 27.2 222 .0 34.3 28 .10 1.6 .07 280 205 182 433 7.2 (3 td 1949-50 13.5 .05 .03 .0 51.9 13.8 25.8 193 .0 62.8 21 .10 .02 .39 286 187 158 466 i.y7 Q {-.. 1950-51 6.8 .01 .02 .0 53.6 18.9 28.4 234 .0 49.0 18 .06 .03 .20 291 212 192 487 7.9 tn 1951-52 6.8 .01 .02 .0 53.6 18.9 28.4 234 .0 49.0 18 .06 .03 .20 291 212 192 487 7.9 O 1952-53 12.0 .01 .00 .0 66.4 23.8 33.2 264 .0 69.6 28 .10 2.6 .21 366 264 216 549 " s 1949-50 7.0 .02 .01 .0 14.4 5.2 13.7 62 .0 20.2 16 .05 .07 .07 107 57 51 199 7.7 > 1950-51 6.5 .01 .01 .0 12.8 5.5 12.0 65 .0 10.5 17 .06 .05 .08 96 55 53 157 7.8 H 1951-52 6.5 .01 .01 .0 12.8 5.5 12.0 65 .0 10.5 17 .06 .05 .08 96 55 53 157 7.8 H 1952-53 11.6 .01 .01 .0 13.7 4.5 13.6 60 .0 7.9 16 .20 .01 .09 97 53 49 160 7.5 W 1949-50 6.0 0.02 0.02 0.0 16.5 4.9 11.7 63 0.0 17.8 9 0.05 0.05 0.10 97 61 52 162 7 5 1950-51 6.5 .01 .02 .0 15.9 4.2 11.2 65 .0 15.1 9 .05 .05 .12 94 57 53 156 7.7 1951-52 8.1 .00 .05 .0 12.8 5.6 9.8 61 .0 9.9 10 .06 .04 .14 85 55 50 139 7.4 1952-53 7.8 .00 .08 .0 18.5 6.3 9.6 78 .0 12.6 10 .05 .18 .04 103 72 64 173 7.7 1949-50 8.5 .02 .01 .0 16.4 5.6 12.4 66 .0 13.2 13 .05 .05 .10 101 64 54 173 75 1950-51 8.5 .01 .03 .0 15.5 5.8 11.7 70 .0 12.6 12 .05 .05 .14 100 63 57 171 7.7 1951-52 5.3 .00 .04 .0 15.0 5.0 10.9 64 .0 10.7 12 .05 .04 .09 90 58 52 151 7.8 M 1952-53 8.6 .00 .08 .0 15.5 5.6 10.3 66 .0 1M 13 .95 .22 .06 98 62 54 165 7.5 1949-50 7.0 .05 .03 .0 9.5 3.7 6.5 42 .0 8.7 7 .09 .10 .16 63 39 34 106 7.3 1950-51 3.0 .00 .05 .0 7.5 3.4 5.3 34 .0 8.7 5 .05 .04 .12 50 33 28 85 7.3 1951-52 4.1 .06 .04 .0 6.4 1.0 6.3 21 1.8 4.8 6 .05 .06 .09 41 20 20 65 9.1 1952-53 6.7 .02 .00 .0 17.4 5.0 8.8 66 1.8 13.1 7 .16 .20 .12 93 64 57 147 8.6 1950-51 8.0 .01 .02 .0 28.0 10.2 19.2 120 .0 14.3 29 ,,.04 .05 .15 168 112 98 297 7 7 1951-52 8.0 .01 .02 .0 28.0 10.2 19.2 120 .0 14.3 29 .04 .05 .15 168 112 98 297 7.7 1952-53 13.0 .02 .00 .0 32.0 11.7 20.2 133 .0 21.9 28 .02 .01 .09 192 128 109 329 8.1 a Supplies downtown, commercial, waterfront areas of the city, and Peninsula communities as far south as San Carlos. b Supplies residential areas of the city. c Average analyses of water served, in 1949 to Peninsula communities south of San Carlos and in 1950-52 to Peninsula communities south of San Carlos and some communities in Alameda County. d Supplies Coast County Water District. 44 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA Table 17. Ranges in chemical constituents in water served to consumers, San Francisco Water Department, July 1, 1949 to June 30, 1953 [Analyses by San Francisco Water Department] Alkalinity Hardness Dissolved Chloride Turbidity Temp, Source Year as CaCOs as CaCOa pH op oxygen (ppm) (ppm) (ppm) (ppm) (ppm) a !949-50 8-16 50-68 7.3-7.9 44-68 4.6-13.2 1950-51 45-58 46-64 7. 3-7.9 0. 5-12 50-70 7.2-10.9 1951-52 9-13 43-57 48-70 7.2-7.9 1-14 50-70 6.0-12.0 1952-53 7-13 47-70 52-78 7.2-7.9 .5-14 51-71 6.7-11.4 San Andreas lines...... 1949-50 1950-51 11-18 50-62 56-72 7.5-8.2 1.0-18 49-68 6.8-12.5 1951-52 12-18 40-56 54-66 7.3-7.9 1.0-11 48-69 7.6-12.0 1952-53 9-16 51-61 60-71 7.2-8. 1 1. -9.5 50-70 7.2-11.4 Bay Crossing lines'3 ...... 1949-50 5-14 13-112 16-118 7. 1-7.9 46-66 7.6-12.4 1950-51' 4-17 10-154 12-164 7. 1-9.2 .5- 9.0 47-70 5.7-12.7 1951-52 4-14 15-71 16-68 7.6-9.4 .5- 7.5 48-67 6.0-12.8 1952-53 c l-16 c !6-97 C 17-101 7.4-9.4 .5- 5.0 48-70 6.7-11.8 a The ranges of 1949-50 fiscal year are for the Peninsula reservoirs. " The higher concentrations were for short periods only, and as an index of average chemical content the yearly averages for hardness were 1949-50, 39 ppm; 1950-51, 36 ppm; 1951-52, 36 ppm; 1952-53, 56 ppm. °For a few short periods hardness reached 183 ppm, alkalinity 143 ppm, and chloride 30 ppm. CRYSTAL SPRING LINES 60 40- 20- 0 80 SAN ANDREAS LINES 60- 40 20H 0 1949-52 1949-52 1949-52 1949-52 1949-52. 1949-52 1950-53 1950-53 1950-53 1950-53 1950-53 1950-53 July August September October November December January February March April May June Analyses by San Francisco Water Department Figure 19. Hardness of water delivered to consumers by San Francisco Water Department. PUBLIC WATER SUPPLY SYSTEMS 45 K ;a^m^cou3CMiri Bacterial analyses of raw water shows most proba a ;t-cococococooo ble number of coliform organisms for 100 milliliter ocorjtoinNcoco o ^ ' "S ^» C-OOCOC-C-COININ (MPN/100ml), ranges from 13 to 2400. lishs ^* ^* ^* ^ ^* ^* ^* ^* !§«ir East Bay Municipal Utility District COOOU5CDONCO « £> COCT>O)OOOOC-C-C- The East Bay Municipal Utility District obtains its ^ -a water supply from two sources, the Mokelumne River < a impounded in Pardee Reservoir, and from runoff into CO-^mOrfOOO N. rHOOCT)COt>CO the four terminal reservoirs, San Pablo, Upper San !/] « NNCNJN> 1> 1« IT-H _ W O Leandro, Chabot, and Lafayette. The combined total rt S <-> -^ C nj capacity of the five reservoirs is 311, 400 acre-feet or 0 "0 n EH tn U 101, 500 million gallons. JS£ rtw The District has a permit to divert 200 mgd (310 cfs) 0) ^ OO^POCOC-OiC- from the Mokelumne River and has filed an application £0 ^"C-C-^tOOOTtlCO to divert an additional 125 mgd (194 cfs) or a total of ffi l~ 364,000 acre-feet annually. a tocot-c-cDT} V) ment plant is from the Mokelumne River; however, this '-ilNCO'-i'-it-tOC- plant can treat water from Lafayette Reservoir if the (NINr-ININ'-l'-l.-l CD f ""^ Mokelumne Aqueducts are shutdown. Treated water is g S wi S1 - 2 stored in distribution tanks and reservoirs (total ca 1 M ~ pacity, 390 million gallons). The total pumping capac ity of the distribution pumping plants is 238 mgd. C-ONinN^N^ ^8-3- ininin-^Tti-^iTtiTti Url "o2 U^- All water supplied to the distribution system is treated and filtered; treatment included coagulation with alum, a ^~. U50OCO'*1 ' linOiO O IN r-tf^^r-tf^r-lr-tC* pH adjustment with lime for corrosion control, sedimen S O i-H -r-l tation, filtration through rapid sand filters, and chlori- cn en nation. At times, activated carbon is used for taste and odor control. Copper sulfate is used in the storage reservoirs to control algae. The District serves an area of 208 square miles with a population of nearly 1 million people. Besides sup plying water to Oakland, it supplies many cities, towns, and unincorporated areas in Alameda and Contra Costa Counties. Tables 19 and 20 show the quality of water from the rt four principal sources and the quality at the different 0) >< treatment plants. The supply obtained from the Mokelumne River is soft mountain water. Total dissolved solids, chlorides, and sulfates are low, and hardness ranged from 20 to 26 ppm for the monthly analyses during the 1953 calendar year. San Pablo, Upper San Leandro, and Chabot waters are considerably more concentrated and harder. Hardness ranged from 192 ppm for Chabot water to 108 ppm for San Pablo water. Generally tur tOC-COCT)O'-ICMCO Tj [Analyses by East Bay Municipal Utility District; results in parts per million except pH] Har dness Specific Alkalinity as <3aCOs conduct- Month Alumi Manga Cal Magne as Chlo Silica Fluo- Source and num nese cium sium bicar ride ride (Si02 ) (Fe) (Na) solids Non- (micro - PH year (Al) (Mn) (Ca) (Mg) bonate (S04) (Cl) (F) Total carbon mhos at (HC03) ate 25°C) June 1950 7.2 0.4 0.00 0.0 6.0 0.7 4.7 24- 1. 1 5 0. 1 25 18 0.9 9. 1 June 1951 9.4 .2 .00 . 0 7.8 1. 1 5.7 34 1. 3 5 .0 44 24 .0 8 9 June 1952 5.5 .7 .02 .0 6.4 .7 1.0 22 1.6 1 . o 46 19 .8 8 9 June 1953 9.8 .3 .03 . 0 6.9 1.0 1.6 27 1.4 1 .0 48 21 .0 42.5 9.4 San Pablo...... June 1950 1.3 2.6 .00 . 0 23 5.6 13 80 24 13 . 1 112 81 15 8 0 June 1951 .9 4. 5 .00 .0 30 8.0 21 109 41 15 . o 181 108 19 8 3 June 1952 2.2 1.3 .02 .0 35 10 18 115 56 13 . 1 209 131 37 8 1 June 1953 1. 1 1.5 .02 .0 33 11 22 120 52 16 . o 207 127 29 300 8. 3 June 1950 5.6 .6 .00 .0 36 13 20 141 45 18 .0 220 144 28 7 9 June 1951 7.9 1. 1 .00 .0 35 13 19 139 42 16 . 1 236 140 26 8 1 June 1952 10.7 .8 .03 .0 36 12 13 127 48 11 . 1 215 141 37 8 0 June 1953 3. 2 2.0 .05 . o 35 12 19 141 44 12 .2 214 137 21 290 8.4 Chabot...... June 1950 .4 .9 .00 .0 48 22 34 199 71 32 .2 316 208 45 7.9 June 1951 3.7 1.5 .00 .0 49 21 33 190 79 30 . 2 355 208 52 8, 1 June 1952 7.0 1.4 .01 . o 37 15 17 132 57 16 " . 2 232 153 45 7 9 June 1953 .9 1.6 .02 ..o 41 18 21 161 60 18 . 1 259 175 43 375 8.0 O en o O dd PUBLIC WATER SUPPLY SYSTEMS 47 Table 20. Range in monthly chemical and physical characteristics of treated water, East Bay Municipal Utility Dis trict, 1953 [Analyses in parts per million except pH by East Bay Municipal Utility District] Chloride Hardness Alkalinity (Cl) as CaCO3 as CaCC>3 Turbidity pH Treatment plant Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Upper San Leandro...... 14 11 156 134 130 96 0.6 0.2 8.4 7.9 Orinda...... 1 1 26 20 26 18 2 .2 9.5 8.9 San Pablo...... 18 14 130 108 106 88 .2 .2 8.3 7.9 Chabot...... 19 15 192 155 144 118 .6 .2 8.5. 7.8 Lafayette ...... 2 1 26 19 26 19 2 .2 9.6 8.9 solution are small for the water supplied consumers. Cache Slough enters the Sacramento River above Rio These waters can be readily classed as of the calcium Vista, and drains an area used mostly for agriculture. and magnesium bicarbonate type. The water in the slough is subject to tidal action and is therefore sufficiently circulated to prevent stagnation. Cities of Pittsburg and Martinez and California As noted in the section discussing imported water, Water Service Co. it is of good chemical quality but subject to considerable variation.in total hardness and turbidity. (See table 21.) The city of Pittsburg, serving a population of 14,000 obtains its water supply from the Contra Costa Canal Table 21. Chemical analyses and turbidity measure through the Contra Costa Water District, which is the distributing agency for the canal water. In 1952, the ments of water from Vallejo Water Supply System city replaced its old treatment plant with a new 8 mgd [Analyses by Vallejo Water Supply System; results in plant. Treatment includes coagulation, sedimentation, filtration, and chlorination. parts per million except pH] Alka Hard The city of Martinez, with a population of 8, 216 in linity ness Tur 1950, obtains its water from the canal. The average Date Ca Mg Cl as as pH bidity annual volume of water treated during the 1950-53 CaCOa CaCO3 period was 485 million gallons. The treatment plant has a design capacity of 4 mgd. Treatment includes aeration, chlorination, coagulation, sedimentation, and Untreated Water filtration. July 13, 1953.... 11 50 88 123 The California Water Service Company obtains part Oct. 21, 1953.... 335 112 116 8.0 50 of its supply from the canal. The area served is shown Nov. 2,1953.... 3?, 106 103 7.8 53 pn plate 5. The chemical quality of Contra Costa Canal Dec. 10, 1953.... 20 12 34 96 102 7.8 48 water is described in table 14. Jan. 19, 1954.... 20 7.3 25 82 80 7.6 400 Feb. 17, 1954.... 18 54 52 7 8 150 Mar. 15, 1954.... 19 12 35 90 98 7.4 78 Vallejo Water Supply System Apr. 2,1954.... 26 11 32 108 112 7.5 180 The water supply for the city of Vallejo is obtained Treated Water from the Maine Prairie Branch of Cache Slough, Gordon Valley Creek and Green Valley Creek. Water from the July 13, 1953.... 16 58 61 0.5 latter two sources is stored in Lakes Curry, Madigan, Oct. 21, 1953.... 300 93 122 7.3 .2 and Frey. The city of Vallejo has estimated that Nov. 2,1953.... 32 93 114 7.2 .2 3,400 million gallons would be the annual use for 1953- Dec. 10, 1953.... 22 12 34 75 10 7.4 .2 54,of which 76 percent would be obtained from Cache Jan. 19, 1954.... 20 9 25 58 88 6.4 Slough. The safe yield of the system has been estimated Feb. 17, 1954.... 14 59 89 8.3 1.5 as 8, 897 million gallons annually. The water system Mar. 15, 1954.... 23 13 37 67 109 6.7 .2 serves an estimated population of 42,000 people includ Apr. 2,1954.... 29 11 27 75 118 6.7 .3 ing Rockwell, Cordelia, and Mare Island. It is pro posed to provide service to areas such as Travis Air Force Base, Fairfield, and Suisun, which lie along the The treated water is generally a little harder than route from Cache Slough. Cache Slough water. Turbidities are reduced to a few tenths of a part per million in the treated water. The Fleming Hill treatment plant, with a capacity of 14 mgd is 1 mile north of the city. Treatment includes Analyses of samples taken in June 1950, of Green pre- and post-chlorination, lime for pH and corrosion Valley Creek and Gordon Valley Cre.ek, minor sources control, addition of carbon, coagulation and rapid of supply, indicate water from these Creeks is a cal sand filtration. cium and magnesium bicarbonate type (table 22). 48 WATER RESOURCES OP THE SAN FRANCISCO BAY AREA Table 22. Chemical analyses and related physical The water is moderately hard and can be classed as a measurements of water from Vallejo Water Supply calcium and magnesium bicarbonate type. System. [Analyses by Vallejo Water Supply System; results in North Marin County Water District parts per million] The water supply for the North Marin County Water Green Gordon District is obtained entirely from Novato Creek. The Constituent Cache Valley Valley Novato Creek treatment plant, 3 miles west of Novato, Slougha Creekb Creek 0 has a designed capacity of 4 mgd, and and overload capacity of 7 mgd. The treatment consists of pre- and Silica (SiO2 )...... 15 28 5.0 post-chlorination, addition of activated carbon, lime Iron (Fe)...... 0 .0 and alum, sedimentation, and rapid sand filtration. The Manganese (Mn)...... 0 . 0 total water delivered during 1953 was 2, 200 million Calcium (Ca)...... 17 6.0 41 gallons. The system supplies an estimated population Magnesium (Mg)...... 13 3. 0 17 of 10, 000 people in the communities of Novato, Black Sodium (Na)...... 21 clO r?7 Point, and Ignacio. Potassium (K)...... ,...... 2.0 Carbonate (COs)...... 0 0 0 Novato Creek, an intermittent stream, drains a Bicarbonate (HCOs)...... 110 37 183 small area of about 17 square miles above Novato. The Sulfate (S04 )...... :. 26 10 65 '8 average discharge for the 7-year period ending Sep Chloride (Cl)...... 20 11 tember 1953, was 7. 39 mgd (10. 6 cfs). Fluoride (F)...... 2 .0 .0 Nitrate (NOs)...... 3 1.0 . 0 Analyses of Novato Creek water indicate that it is of Dissolved solids...... 248 90 263 fairly good quality. (See table 5.) The water is a cal Hardness as CaCO3 cium and magnesium bicarbonate type with low dissolved Total...... 96 29 170 solids. Noncarbonate...... 0 22 Color...... 10 5 pH...... 7. 7 7. 9 Marin Municipal Water District Turbidity...... 10 25 a Near Vallejo Pumping Plant, average for May 1953. Marin Municipal Water District obtains most of its supply from surface water and only a small part from Raw water, average for June 1950. c Calculated Na + K. springs. The reservoirs from which the district draws its supply and their capacities are: Alpine Lake, 3,000 Dissolved solids and hardness for Green Valley Creek million gallons, Bon Tempe, 1, 400 million gallons, were 90 and 29 ppm, respectively, and for Gordon Lagunitas, 111 million gallons and Phoenix, 199 million Valley Creek 263 and 170 ppm, respectively. gallons. Uncompleted Kent Reservoir will increase storage capacity by 5, 500 million gallons. The com munities supplied by the system are San Rafael, San Napa Water Department Anselmo, Woodacre, Fairfax, Ross, Kentfield, Green- brae, Larkspur, Corte, Madra, Mill Valley, Sausalito, The city of Napa obtains its entire supply from surface Tiburon, Belvedere, Forest Knolls, San Geronimo, water stored in Milliken and Conn Reservoirs. Milliken Lagunitas, Hamilton Air Force Base, Fort Baker, and Reservoir obtains its water from Milliken Creek, and Naval Net Depot. The total consumption for the Conn Reservoir obtains its water from Conn, Childs, 1952-53 year was 4, 500 million gallons. Moore, and Sage Creeks. The capacities of the Milliken and Conn Reservoirs are approximately 640 million gal The following analysis of a sample of the Marin Dis lons and 10,000 million gallons, respectively. The system trict supply, -collected January 2, 1953,at the inlet to serves an estimated population of 20,000 and has an Forbes distribution reservoir, indicates good quality. average output of 4 mgd and a maximum transmission capacity of 17 mgd. Treatment includes chlorination. [Results in parts per million except conductance] An analysis of water taken from the Conn pipeline March 30, 1953, before chlorination, follows: Sodium (Na).,...... 6.2 Dissolved solids...... 97 Magnesium (Mg)...... 7.6 Total hardness as 49 [Analysis by laboratories of Brown and Cadwell, San Calcium (Ca)...... 7.1 CaCOs. Francisco, Calif.; results in parts per million ex Bicarbonate (HCO3).... 20 Noncarbonate...... 33 cept pH and conductance] Sulfate (SO4 )...... 31 Conductance 117 Chloride (Cl)...... 10 (micromhos). Silica (SiO2 )...... 16 Chloride (Cl)...... 5 Iron (Fe)...... Nitrate (NO3)...... 0 Manganese (Mn)...... Total solids (evap- 150 During the summer, the concentration of dissolved Calcium (Ca)...... 18 oration). minerals is a little higher because of evaporation from Magnesium (Mg)...... 20 Total hardness as 127 the reservoirs, considerably less rainfall, and less Sodium (Na) and 1, CaCOs. runoff into the storage reservoir. potassium (K). Alkalinity as CaCOs.. 116 Bicarbonate (HCOs)... 132 Specific conduct- 256 Hardness of the water delivered during the period Carbonate (COs)...... ° ance. July 1951 to June 1952 varied from 65 ppm in Sulfate (SO4 )...... 14 pH...... 7.9 July to 42 ppm in February (table 23). WATER USE 49 Table 23. Physical quality and pH of raw and treated waters, Marin Municipal Water District, July 1951 to June 1952 Lake Alpine (raw water) Distribution system (treated water) Month and year Turbidity Turbidity (ppm as Color pH- (ppm as Color pH Si02) Si02) 1951 July...... 2.2 18 7.7 2.2 15 7.7 a9 34 6.9 6 18 7.2 September ...... 4. 5-8 15-22 6.9 2.2-4.5 10-12 7.7 4. 5-8 15-25 7.0-7.7 4. 5 18 7.7 7.7-9.5 20-30 6.8-7.3 6-9.5 12-30 7.0-7.7 December...... 22-35 55-80 7.3 1.3-2.7 3-8 6.3-6.9 1952 13 45-55 7.4 1.1-3.5 3-8 6.3-6.9 February...... 9.5 35 7.3 1.0-1.7 3-8 6.6-7.3 March...... 6-7.8 25-30 7.7 1.0-2.5 4-10 6.3-7. 1 April...... 4. 5-7.8 25 7.3 1.0-2. 5 3-10 6.3-7. 1 May...... 2.7-4.5 15-25 7.3 1.0-2.7 3-18 6.9-7.7 June ...... 2. 2 15 7.7 1.7 15 7.7 1 Increase in turbidity and color due to changing from top to second intake valve. During the same period, turbidity measurements of Data regarding the use of water by domestic, indus Lake Alpine water, the major source of supply, ranged trial, commercial, and other consumers show some from 2. 2 ppm in July 1951 to 35 ppm during November. general trends. Domestic use per capita has increased practically every year recently and in 1950 was about Treatment of the water includes chlorination and the 66 gallons per capita per day. The rapid development use of alum for sediment removal. Only one reservoir, of the area has increased the demands for water for Phoenix Lake, required copper sulfate treatment for industrial and commercial use. In 1950 the industrial algae control during the year. 400,000- EXPLANATION WATER USE Based on studies made by California Division of Water Resources the gross demand for water in the San Fran cisco Bay Area in 1949 was about 710, 000 acre-feet per year, or 630 mgd. About 42 percent, or 300, 000 acre- feet, was used to meet the requirements of irrigated 300,000- agriculture; about 53 percent, or 380, 000 acre-feet,for Commercial use -250 urban requirements; and 5 percent for other require ments. Of the 300,000 acre-feet required for irrigation approximately 70, 000 acre-feet was returned to ground- water storage, mainly in the Santa Clara Valley. This gross demand is met from developments of both local and imported waters which in 1954 were capable of supplying a little more than 1, 000, 000 acre-feet. Pres 200,000- ent installations, developing local surface and ground- water supplies, have a yield of about 480,000 acre-feet. The area using water at the present time totals about 439, 000 acres or 17 percent of the land in the San Francisco Bay Area. An additional 272,000 acres are devoted to agricultural land that is not irrigatated. Plate 5 shows the areas served by nine public water 100,000 systems in the San Francisco Bay Area. Urban Use Of the 380, 000 acre-feet, or about 340 mgd, required for urban use 50 percent is for domestic use, 37 percent for industrial use, 8 percent for commercial use, and 5 percent for other uses (parks, institutions, etc.). Figure 20. Urban use of water, San Francisco Bay (See fig. 20.) Area, 1950. 50 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA use was about 49 gallons per capita per day, the com serves the other major urban areas, are 68 percent mercial use was about 10 gallons per capita per day. and 32 percent. Other uses were about 7 gallons per day per capita. Therefore, the total urban use is about 132 gallons per capita per day. Industrial Use In the city of San Francisco, 47 percent of the water Some general statements can be made and figures is used for domestic purposes and 53 percent for in given on the industrial use of water, based on a field dustrial and commercial uses. Corresponding figures survey made by the California Division of Water Re for the East Bay Municipal Utility District, which sources during the period 1948 50 (table 24). Table 24. Water demands by industry, San Francisco Bay Area, 1948-50 [Source of data: California Division of Water Resources] Number For the establishments sampled Type of of establish Maximum Minimum Average Total Net Unit industry ments demand^ demand, demand, demand, area, demand, sampled acre-feet/yr. acre-feet/yr. acre-feet/yr. acre-feet/yr. acres acre-ft/acre/yr. Chemical products... 26 11, 520 0.2 597 15, 531.0 575. 5 27. 0 Contractors...... 8 .9 .03 .4 2. 9 6. 5 .45 Drayage...... 10 17. 6 .2 3.0 30. 1 23.2 1.3 Food...... 9 387 1. 1 l64 935.0 34.2 27. 3 .Lumber and allied 10 .03 1.0 10.0 15. 3 . 65 products. Metal products...... 56 15, 100 .04 321 18,001.4 490. 6 36. 7 Metal refining...... 4 322 5. 5 148 592. 3 106.6 5.6 Miscellaneous mfg. .. 9. 1.2 .04 .5 4. 1 4. 3 . 95 Oil refineries ...... 4 6, 752 -1,467 3, 797 15, 186.6 1,194.0 12. 7 Paper and allied 11 10, 770 .8 1,572 17,293.0 112. 7 153.4 products. 4 575 7.3 153 610. 7 17.4 35. 1 War ehous es and 14 .4 5. 9 8.3 .71 storage. Wholesale butchers, 18 714 90.3 1,624. 9 130.4 12. 5 meat packers, etc. Wholesale 56 13. 2 .05 1.2 64. 7 64.6 1. 0 distributors. Lesser categories: Bakeries...... 2 40. 5 4. 5 22. 5 45.0 1. 2 37. 5 1 338.0 3.2 105. 6 Cold storage...... 3 22. 1 66. 3 4. 3 15.4 1 120. 3 2. 1 57. 3 Extracts...... 2 23. 1 1.6 12.4 24. 8 1. 5 16. 5 1 52.3 1. 6 32. 7 Nonalcoholic 3 24. 5 1. 1 16.4 49. 2 4. 5 10. 9 beverages. Printers...... 2 45. 6 7.3 26.4 52. 9 4. 5 11. 8 Railroad yards..... 1 328. 6 191. 0 1.7 Sugar refineries..: 1 1,574. 7 11.0 143.2 Tanneries...... 2 88. 6 80.7 84.6 169.3 2. 9 58.4 Others...... 7 16. 7 116.8 38.3 3.0 Total or mean... 265 72, 830.8 3,049. 7 23. 9 ^Some private wells have been abandoned in recent vate wells and from Sacramento-San Joaquin delta chan years due to salt-water encroachment and those remain nels. Public water systems supply most of the indus ing furnish only a small part of the water required. trial demand mainly from surface water sources. Six establishments in Emeryville obtained approximately 10 percent of their supply from private sources. In the The Calif ornia Division of Water Resources data were Pittsburg area, those industries contacted reported- originally used to estimate the total 1950 use and the pumping a total of 32, 000 acre-feet annually from pri use after ultimate development using the area-depth POTENTIALITIES 51 method. The net area as used in table 24 is defined as Changes in Water Quality with Use ".... the actually developed portion of an area which has been classified. Net area is therefore equal to gross A large percentage of the surface and ground waters area less streets, sidewalks, and vacant areas. " used for domestic, industrial, and irrigation purposes Thirty percent or 3, 450 net acres of the total industrial is returned to the streams and ground-water reservoirs. net acreage in the San Francisco Bay Area was This return water is generally of poorer quality than sampled. For most of the types of industry listed, the the original water. The water used for domestic pur number of establishments sampled is only a small part poses picks up soaps and other household chemicals of those in the Bay Area. The average use tabulated and wastes to increase its total mineral concentration. is for the general type listed and not for any specific The suspended matter in sewage is usually a removable industry within the general category; also the inclusion contaminent, but soluble salts are left in the water. of one or more large water users unduly affects the Process water effluent from most industries and return average and the unit demand. flow from irrigation are higher in dissolved minerals than the original water used and may not be suitable Uses and quantities of water not related to nor in for reuse. cluded in those mentioned above are the use of the sa line bay waters for cooling and for the production of Excessive pumping in some of the ground-water salt in solar evaporation ponds. Steam-electric plants basins may cause the water levels to declineisufficient are located at various points around the bay and use ly to allow saline water from the bay to encroach the about 2,000 mgd for cooling. The solar evaporation water-bearing zones and contaminate the fresh water in ponds occupy 32,000 acres along the southern shores the underground reservoir. of San Francisco Bay. About 1, 000, 000 tons of salt is produced annually from 40, 000 acre-feet of saline water. An additional 9, 350 acres will be developed POTE NTIALITIES northwest of Vallejo between the Napa River and Sonoma Creek. Since the Bay Area is one of deficient water supply, demands for more water will have to be met largely by importations from outside the area. Only a few Irrigation small additional surface-water supplies are econom ically feasible within the San Francisco Bay Area. The Surface Water ground-water basins cannot support large additional withdrawals. However, the present potential of the In 1954, the land devoted to agriculture in the San various public water systems exceeds the present de Francisco Bay Area totaled about 464, 000 acres. Of mands. this total, about 35 percent, or 163, 000 acres, was used for irrigated agriculture. The 1953 demands and safe yields of six public water systems are given in table 25. Safe yield is defined as The use of surface water for irrigation in the San the amount of water which can be drawn annually from Francisco Bay Area is a minor part of the total use for a given source without creating a water shortage in irrigation. Stanford University diverts about 900 acre- any year. feet annually from Los Trancos and San Francisquito Creeks for irrigation on the campus. Fragmentary The demand for irrigation water is met almost en records indicate that about 500 acre-feet per year is tirely from ground-water basins and generally is in pumped from Los Gatos Creek, and that about 4, 000 localities where water is not otherwise abundant. In acre-feet per year is pumped from Coyote Creek. A creased demands on small supplies, some of which few privately owned pumps divert small amounts of are now- overdrawn, will increase pumping lifts and water from other streams in the area. costs. The rising cost of pumping and the expected in creased cost to provide supplemental water will even tually force an improvement in the present irrigation Ground Water methods. If the present efficiency of irrigation methods The lands totaling approximately 163, 000 acres used for irrigated agriculture are supplied almost entirely Table 25. Present demands and safe yields of public from ground water. The withdrawal of ground water water supply systems for irrigation in 1950 was on the order of 300, 000 acre- 1953 demand feet. Less than 5 percent of this total was used in the Public water system Safe yield valleys north of the bays. About two-thirds of the (acre-feet) (acre-feet) ground water for irrigation was used in Santa Clara 140,000 230,000 Valley, and nearly all of the remainder in Alameda East Bay Municipal Utility 130,000 240,000 County, on the alluvial plain near the bay, and in Liver- District. more Valley. Only minor amounts of ground water are Contra Costa County Water 33,000 194,700 used for irrigation in Ygnacio, Clayton, Concord, and District. San Ramon Valleys. City of Vallejo...... 11,000 27,300 City of Napa...... 3, 300 12,200 Studies by the California Division of Water Resources Marin Municipal Water 13,400 a !8, 700 indicate that the present irrigation methods used in the District. Livermore Valley, Santa Clara Valley, and southern Alameda County result in the consumption of approxi a Upon completion of Lower Lagunitas Project, now mately 60 percent of the water applied. (1954) under construction. 52 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA of about 60 percent could be increased to 70 percent, Reservoir sites capable of yielding additional surface- an appreciable amount of water would be available for water supplies amounting to 6, 000 to 10, 000 acre-feet additional use. can be developed in the Napa Valley. The California Division of Water Resources has es The possibility of developing additional surface water timated that with 85 percent urbanization, the total use within the Bay Area in Sonoma County is poor; such under ultimate development will be between 3, 000, 000 projects would be costly or would yield small quantities and 3,400,000 acre-feet annually, depending on whether of water. However, reservoirs yielding about 10, 000 or not the tidelands are reclaimed. It is assumed that acre-feet annually could be developed in Sonoma Valley. a truck-farm type of agriculture will occupy 15 percent of the area. The figures were derived by applying a The Marin Municipal Water District has the Lower factor of water use to each class of land use. Lagunitas Project under construction in 1954. It will augment the present supply by about 10,000 acre-feet An alternate estimate based on an. ultimate population per year. The reclamation and utilization of sewage of 13, 400, 000 and a gross water use of 172 gallons per and waste waters are important considerations in capita per day would require a total use of approximately densely populated areas such as those bordering San 2, 600, 000 acre-feet. Comparable figures for 1950 are: Francisco Bay. The dry-weather sewage flow in the population, 2,560,000; gallons per capita per day, 132; San Francisco Bay Area during 1949 totaled about and acre-feet, 380, 000. 210, 000 acre-feet on the basis of data furnished by agencies operating sewage works. Most of this amount The rapid growth of suburban developments during either receives or will receive primary treatment be the past 10 years has encroached upon valuable agricul fore it is discharged into the bay. tural land and also upon undeveloped mountain and foot hill areas. The continued urbanization of agricultural The feasibility of a project for the reclamation and lands will change the present pattern of water use. utilization of sewage depends upon several factors. Reclaimed water of suitable mineral quality could be In contrast to the present water service area of about used directly for irrigation and by certain industries. 439, 000 acres (17 percent of the total land area), the However, in general, the demand would not be contin ultimate habitable area has been estimated to be about uous; and the use of underground reservoirs for regu 1, 316, 000 acres or 52 percent of the total. Present latory purposes would allow the treatment plants to or additional water-service agencies will have to meet operate at capacity. The reclaimed water should pos the demands of this future development. An additional sess a mineral quality at least comparable with that of 158,000 acres of tideland are susceptible of reclama local ground-water supplies so that prolonged use of tion and would use approximately 380, 000 acre-feet of such water for irrigation will not result in the deteri water annually. Also included in the Bay Area are oration of the chemical quality of the local supplies. 47,000 acres of non-water-requiring lands which con The feasibility would also depend on the cost of the de sist of powder storage areas, tank farms, and solar livered water, comparing favorably with that of water evaporation ponds for the production of salt. at least equal in quantity and quality that could be ob tained from another source. Also, the quantity and Plate 3 shows the locations of the present urban, quality must be maintained at or above minimum re agricultural, military, and salt-pond areas and the quirements to assure a dependable water supply. areas considered to be urbanized at time of ultimate development. Sewage- treatment has no appreciable effect on the dissolved mineral quality of water which is an impor tant factor when water is used for irrigation. The only Local Supplies practical methods now known to lower the mineral con centrations are dilution with water of better quality, Pescadero Creek and San Gregorio Creek in San or elimination of the contamination at its source. Mateo County are possible sources of water for the ag ricultural area along the ocean. The types of crops Each individual sewage reclamation project should grown and the prevailing summer fogs in these areas be considered separately, and detailed studies will be make only limited irrigation necessary. Runoff at the necessary before its feasibility is or is not established. gaging station on Pescadero Creek during the 2 years Ultimately these sources of water will be investigated. of record has been 66, 920 and 31, 900 acre-feet. Over a long period, it has been estimated that the runoff will average 40, 000 acre-feet. Imported Supplies Additional surface storage, in conjunction, with Several proposals for the importation of additional ground-water basins is feasible on upper Alameda water to the San Francisco Bay Area have been made. Creek, San Antonio Creek, and Arroyo del Valle. Some of these systems are under construction; some Storage on upper Alameda Creek and San Antonio Creek are in the authorized or advanced planning stage; and could develop about 11, 000 acre-feet, and about 9, 000 others are still being studied without any definite plans acre-feet could be developed in the Livermore Valley as of 1954. by construction of a dam on Arroyo del Valle. The city of San Francisco plans to enlarge its present The East Bay Municipal Utility District plans to de development to meet increased demands for many years. velop a reservoir of 4, 300 acre-feet capacity on Pinole An expanded HetchHetchy system plus the present local Creek by 1960. The dependable yield has been es resources will give a combined yield of about 500,000 acre- timated at 3, 000 acre-feet annually. feet per year, or more than three times the 1950 demand. WATER LAWS 53 The East Bay Municipal Utility District, which cur (b) Several elaborate but physically feasible plans to rently imports about 115, 000 acre-feet annually from bring large quantities of Eel River water into the its Mokelumne River Project, can enlarge that project counties in the northern part of the San Francisco Bay from its present capacity of 175, 000 acre-feet to Area are under consideration. One such plan envisions 224, 000 acre-feet per year. A new application now on reservoirs on Middle and South Forks of Eel River with file with the State of California requests rights to an diversions to the Russian River basin in Potter Valley, additional 140, 000 acre-feet per year from the Moke a powerhouse, pumping plants, conduits, and a ter lumne River. The' total yield of the project would then minal storage reservoir near Novato. be 364, 000 acre-feet per year or more than three times the 1950 demand upon it. (c) Barriers across the bays are most involved pro posals, because they encompass, among other factors, In 1953 the Contra Costa Canal delivered about 33,000 problems of transportation, sedimentation, pollution, acre-feet to the San Francisco Bay Area. This is only fisheries, navigation, and salinity control, the main 17 percent of the ultimate capacity of the canal where tenance and preservation of existing levees and farm it enters the area. For comparative purposes, this land in the delta, the amount of outflow from the delta, canal ultimately would be able to meet the present ur and the effect upon the operation of the Central Valley ban demand for water in San Francisco, San Mateo, Project. In general, these plans call for earth and and AlamedaCounties. rock fill dams across the bay to impound the fresh water now discharging into the bay and ocean, thus The U. S. Bureau of Reclamation has made a pre forming large fresh water lakes adjacent to present in liminary report on the feasibility and cost of supplying dustrial areas and future reclaimed lands. water from the Contra Costa Canal to the area near Richmond. In that report, it was estimated that about The north bay barrier has been proposed at various 20, 000 acre-feet per year could be made available at sites between Point San Quentin-Richmond and Chipps a cost of about $30 per acre-foot, not including distri Island near Pittsburg. The south bay barrier sites bution and treatment costs. are from just south of the San Francisco-Oakland Bay Bridge to 'Candlestick Point-Bay Farm Island. Under construction in 1954 and scheduled for comple Some of the plans include a fresh water ship channel tion in 1958 is the Solano or Monticello Project of the along the east shore of the bay which would connect the U. S. Bureau of Reclamation. Its main feature is a two fresh water lakes. dam that forms a storage reservoir across Putah Creek west of the town of Winters. A diversion dam a short The outflow from the Sacramento-San Joaquin Delta distance downstream from the storage reservoir and a is not known reliably. Most studies have estimated canal serving the area from north of Dixon to west of the outflow, which is the fresh water available to this Cordelia are also parts of the project (plate 5) which project, by indirect methods. The California Division together with coordinated operation of ground-water of Water Resources made a 17-day tidal cycle measure basins will provide water for irrigation of about 56,000 ment of the outflow in September 1954. Studies of acres of new land and about 19,000 acres of land re methods that will result in a record of daily outflow are quiring supplemental water, and will also provide about being made. 27, 000 acre-feet of water for municipal and industrial uses in the vicinity of Fairfield and Benicia. A large The effect of a north bay barrier upon the operation portion of these uses will be outside the San Francisco of the Central Valley Project is under investigation. Bay Area. Anticipated charges for water at the diver The Central Valley Project requires the transfer of sion dam on Putah Creek are $2. 65 and $15. 00 per Sacramento River water across the delta to San Joaquin acre-foot for irrigation and municipal water, respec River delta channels where the water is pumped into tively. Distribution costs from that point will be addi the Delta-Mendota Canal for irrigation in the San Joaquin tional. Valley. As part of the California Water Plan, the State Water The proposed Feather River Project would also Resources Board has proposed the Feather River Proj transfer water across the delta and pump it into canals ect and is making detailed investigations. A feature for distribution in the San Joaquin Valley, southern of this development is the Santa Clara-Alameda diver California, southern Alameda County, and Santa Clara sion which involves two pumping plants with a total lift Valley, the latter two localities being in the San Fran of 722 feet, canal, tunnels, aqueducts and terminal cisco Bay Area. storage reservoirs. Water would be diverted from the Sacramento-San Joaquin Delta through Old River and The feasibility of construction of one or both of the Italian Slough and be distributed in Livermore Valley, barriers will depend upon whether present and future southern Alameda County and Santa Clara County. investigations can ascertain that construction of one or (See plate 5.) The present proposal calls for an annual more barriers will actually conserve a large supply of diversion of 127,000 acre-feet from the delta to the usable water and that all the interrelated problems Santa Clara-Alameda area. This feature of the Feather mentioned above can be resolved. River Project could be built before the construction of the Oroville Dam on the Feather River, to utilize sur plus water from the delta. WATER LAWS Other proposals under preliminary study are: Under California law both riparian and appropriative rights are recognized in water of surface streams and (a) Transmountain diversions from streams in Santa also "subterranean streams flowing in definite chan Cruz County to the Santa Clara Valley. nels. " The principles of riparian and appropriative 54 WATER RESOURCES OF THE SAN FRANCISCO BAY AREA rights are diametrically opposed to each other. A ri share is determined on the basis of reasonable use parian right is based on ownership of land contiguous under the circumstances. to a stream. Under riparian rights the owner of land adjacent to a stream is entitled to use the full natural The right of an owner of overlying land to the use of flow, undiminished in quantity and unchanged in quality. percolating waters on his land is paramount to that of However, a California constitutional amendment of an appropriator who takes from the same ground-water 1928 imposed reasonable use upon riparian rights. This source for distant use. However, such appropriator amendment limits riparian and other rights in water may take any surplus above the reasonable, beneficial courses to the portion of the flow useful for reasonable needs of such overlying lands. Rights to percolating and beneficial purposes under reasonable methods of waters may be acquired by prescription against the diversion. Where supply is insufficient, all landowners rights of owners of overlying lands who fail to protect with equal rights are entitled to a fair and reasonable such rights. share of the available water. Courts have power to determine and regulate these shares from the evidence. The constitutional amendment of 1928 has Been upheld as a new State policy bringing all water users under the An appropriative right is based on appropriation and rule of reasonableness. This applies to all water rights, use of unclaimed water that is declared to belong to the whether based on the riparian right, or the analogous public. All water in California is declared to be the right of the owner of overlying land, or the percolating property of the people of the State and available for water right, or the appropriative right. Thus rights to beneficial use. This water can be claimed by riparian all waters, surface and underground, which form part right or by appropriation. The water right by appro of a common supply, are correlated under the modified priation is restricted to water used beneficially, and common law doctrines of ownership and use, upon which is forfeited if the water is allowed to go unused for a the doctrine of appropriation is superimposed; all sub specified period of time. The other important feature ject to the test of reasonable, beneficial use. of an appropriative right is that he who is first in time is first in right; during periods of water shortage the later appropriators must forfeit their use in reverse SELECTED BIBLIOGRAPHY order of priority. Published Reports The present Water Commission Act of California was enacted in 1913, and as amended from time to time, is California, Division of Water Resources, 1931, Eco in force today. It provides for permits "for any unap nomic aspects of a salt water barrier below conflu propriated water, or for water which having been ap ence of Sacramento and San Joaquin Rivers: Bull. 28. propriated or used flows back into a stream, lake or _____1933, Santa Clara investigation: Bull. 42. other body of water within this State. " _____1946, Salinas Basin investigation: Bull. 52. _____1952, Progress Report, Reclamation of water Administration of the 1913 Water Commission Act from sewage or industrial wastes. was vested in the State Water Commission, whose California, State Water Resources Board, 1951a, Fea functions are now performed by the Division of Water sibility of Feather River* Project and Sacramento-San Resources of the Department of Public Works, the Joaquin Delta Diversion Projects, State Engineer being chief of the division. A right to _____195Ib, Water resources of California: Bull. 1. appropriate water is initiated by application to the chief _____195 Ic, Santa Clara Valley investigation: Bull. 7. of the division for a permit to appropriate. The statute ____^1954, Water utilization and requirements of provides that this is the only acceptable .procedure. California: Bull. 2. California, State Water Pollution Control Board, 1952, The Water Commission Act provides also for the de Water quality criteria, Pub. 3. termination of rights acquired under the act and for the Calkins, R. D., and Hoodley, W. E., 1941, An eco distribution of water. The Division of Water Resources nomic and industrial survey of the San Francisco Bay may make determinations on petitions of one or more Area; California State Planning Board. claimants to the use of water of any stream system, Clark, B. L., 1930, Tectonics of the Coast Ranges of including both appropriative and riparian rights, the middle California; Geol. Soc. Am. : Bull. v. 46, order and record of determinations to be filed in court no. 4, p. 747-828. as the basis of an adjudication. The courts also, in Clark, W. O., 1915, Ground-water resources of the their discretion, may refer to the Division, as referee, Niles Cone and adjacent areas, California: U. S. suits brought for the adjudication of water rights, sub Geol. Survey Water-Supply Paper 345-H. ject to review, and the Division may act as master or _____1917, Ground water for irrigation in the Morgan referee when requested by a Federal court. Hill area, California: U. S. Geol. Survey Water- Supply Paper 400-E. Ground water not shown to be flowing in a "definite .1924, Ground water in Santa Clara Valley, underground stream" is presumed to be percolating. California: U. S. Geol. Survey Water-Supply Paper Court decisions have established the doctrine of cor 519. relative rights in dealing with percolating ground water. Corps of Engineers and Maritime Administration The doctrine of correlative rights of landowners over (U. S. Department of the Army and Department of lying percolating waters is comparable in many respects Commerce), revised 1951, Port Series no. 30. to the rule of reasonable use applied to the doctrine of Crittenden, M. D., Jr., 1951, Geology of the San Jose- riparian rights of owners of land contiguous to streams. Mount Hamilton area, California: California Div. The courts have ruled that the rights of all landowners Mines Bull. 157. in a ground-water basin are coequal or correlative, and Crowell, H. G. , 1953, Water-supply problems in that one landowner cannot pump more than his share southern Alameda County, California: Paper pre where the rights of others are damaged. The owner's sented to the ASCE, San Francisco, March 3-6. SELECTED BIBLIOGRAPHY 55 Hinds, N. E. A., 1952, Evolution of the California Unpublished Reports landscape: Division of Mines, State of California, Bull. 158.. California, Divisionof Water Resources, 1952a, Water util Jenkins, Olaf, Geologic map of California: Division ization and requirement of the San Francisco Bay Area. of Mines, State of California, Revised unpublished California, State Water Resources Board, in prepara edition. tion, Livermore Valley, southern Alameda County in Lohr, E. W., and Love, S. K., 1954, Industrial util vestigation. ity of public water supplies in the United States, Cardwell, G. T., 1955, Geology and ground water of 1952, Part 2, States west of the Mississippi River: Santa Rosa and Petaluma Valley areas, Sonoma U. S. Geol. Survey Water-Supply Paper 1300. County, Calif. : In U.S. Geol. Survey open file and to McGlashan, H. D., and Briggs, R. C., 1939, Floods be published as a Water-Supply Paper. of December 1S37 in northern California: U.S. Geol. Edmonston, A. D., 1950, Water resources, utilization, Survey Water-Supply Paper 843. and requirements of the San Francisco Bay Area: Moore, E. W., 1940, Progress report of the com Paper presented at hearing of Joint Legislature Com mittee on quality tolerances of water for industrial mittee on Water Problems, San Francisco, Sept. 18. uses: Journal New England Water Works Associa Kunkel, Fred, and Upson, J. E., in preparation, Geology tion, v. 54, p. 271. and ground water in Napa andSonomaValleys, Napa and Morse, R. R., and Bailey, T. L., 1935; Geologi Sonoma Counties, California: U.S. Geol. Survey. cal observations in the Petaluma district, Cali Poland, J. F., 1935, Ground-water conditions inYgnacio fornia, Geol. Soc. Am. Bull. v. 46 no. 10, Valley, California: Unpublished master's thesis, p. 1437-1456. Stanford University. Rantz, S. E., 1956, Flood of January 1952 in Smith M. B., 1934, Ground-water in the Livermore the south San Francisco Bay region, California, Valley, California: Unpublished master's thesis. In U. S. Geol. Survey Water-Supply Paper Thomasson, H. G., Olmsted, F. H., LeRoux, E. F., 1260-D. 1956, Geology and ground-water resources of Solano Taliaferro, N. L., 1951, Geology of San Francisco County, California: In U. S. Geol. Survey open file Bay Counties: Division of Mines, State of California, and to be published as a Water-Supply Paper. Bull. 154. Tolman, C.F., Hide, B.C., Killingsworth, C. C., 1934, Tolman, C. F., 1940, Ground water, salt water infil Ground-water supply and saline contamination of tration, and ground-surface recession in Santa Clara Pittsburg and adjacent industrial area, Contra Costa Valley, Santa Clara County,California: Am. Geophys. County, California: Unpublished consultant report. Union Trans. p. 23-35. Tolman, C. F., Poland, J. F., 1935, Investigation of the U. S. Geological Survey, issued annually, Surface- ground-water supply of the Columbia Steel Co., Pitts water supply of the United States, part 11, Pacific burg, California: Unpublished consultant report. slope basins in California: U. S. Geol. Survey ____1935, Preliminary report concerning results of Water-Supply Papers. test hole no. 1, Columbia Steel Co., Pittsburg, U. S. Public Health Service 1946, Drinking water California: Unpublished consultant report. standards: U. S. Public Health Service Rept., v. 61, .1936, Report on results of drilling wells no. 14 no. 11, p. 371-384, reprint no.2697. and no. 15, Columbia Steel Company, Pittsburg, California: Unpublished consultant report. INT.-DUP. SEC., WASH.. D.C. in387