T.tBF.Al^Y AUG 1 1963 \ THE RESOURCES AGENCY OF CALIFORNIA Department of Wa ter Resources BULLETIN No. 99 RECONNAISSANCE REPORT ON UPPER PUTAH CREEK BASIN INVESTIGATION /VVARCH 1962 univcss;ty of California DAVIS JUM 27 1962 L I E r A R Y EDMUND G. BROWN Governor State of Colifornia WILLIAM E. WARNE Administrator The Resources Agency of California and Director Department of Water Resources 1. The community of Middletown. The largest populated community in the Upper Putah Creek Basin is located between St. Helena Creek (fore- ground) and Putah and Dry Creeks (background). STATE OF CALIFORNIA The Resources Agency of California Department of Water Resources BULLETIN No. 99 RECONNAISSANCE REPORT ON UPPER PUTAH CREEK BASIN INVESTIGATION MARCH 1962 EDMUND G. BROWN WILLIAM E. WARNE Governor Administrator State of California \KY The Resources Agency of California ond Director Department of Water Resources Wl*»— . . I 'r CALIFORNIA DAvm TABLE OF CONTENTS Page LETTER OF TRANSMITTAL xiv ACKNOWLEDGEMENT xv ORGANIZATION, DEPARTMENT OF WATER RESOURCES xvi ORGANIZATION, CALIFORNIA WATER COMMISSION xvii CHAPTER I. INTRODUCTION 1 Authorization for Investigation 2 Objective and Scope of the Investigation 2 Related Investigations and Reports ^ Putah Creek Cone Investigation ^ Investigation of Ground Water of the Lower Lake-Middletown Area 5 State Water Rights Board Decision No. 869 5 State-Wide Water Resources Investigation 6 Other Sources of Data 6 The Area and the Problems 7 The Area Under Investigation 7 The Principal Problems 13 CHAPTER II. WATER UTILIZATION AND REQUIREMENTS 19 Present Water Utilization 20 Present Population 2k Present Consumptive Use and Water Requirements 2k Future Water Requirements 28 Lsuid Classification Survey 28 TABLE OF CONTENTS - (continued) Page Future Water Requirements (continued) Water Utilization Under Ultimate Conditions of Development 3**^ Some Economic Aspects of Water Development 36 Possible Service Areas for Water Development kO Potential Future Water Requirements in Selected SeiTTice Areas ^ Future Land Use ^1 Future Supplemental Water Requirements k6 Effect of Water Rights on Upper Basin Development 50 Nature of Water Rights 50 Riparian Rights 50 Appropriative Rights 51 Correlative Rights to Underground Water 5^ Water Right Applications at Monticello Reservoir 55 CHAPTER III. SURFACE WATER SUPPLY 6I Precipitation ol Records of Precipitation 61 Characteristics of Precipitation 6? Rvinoff 68 Stream Gaging Stations and Records 69 Runoff Characteristics 73 Quantity of Runoff 73 Flood Flows 80 Water Quality 8I General Water Quality Conditions ol ii TABLE OF COHTSIITS - (continued) Pase 2 Water Quality (continued) Uater Quality Problems CHAPTSn IV. GROUinD WATER POEIITIAL ^3 Occurrence of Ground Uater °> on .... 86 Geology Franciscan-ICnoxville Groups 90 Cretaceous Sediments, Undifferentiated 91 Martinez Formation 92 Sonoma Volcanics 9*^ Cache Formation 9^^ Tuff 52 Clear Lake Volcanics 93 Clear Lake Volcanics, Basalt Member 93 Alluvium • • • ■'Oi^ cjh OP Landslides -'^ V/ater-yieldins Capacities of iUluvial Materials 97 Movement, Replenishment, and Depletion of Ground l/ater 9^ Principeil Ground V/ater Basins ^^^ Collayomi-Lons Valleys Ground VJater Basin 101 Geolor' - - - 102 Hydrology -^^^ Present Ground 'u'ater Development HO Potential for Increased Ground 'Jater Development HI 111 TABLE OF COIITEKTS - (continued) Page Principal Ground Water Basins (continued) Coyote Valley Ground Water Basin II5 Geology II5 Hydrolosr 119 Present Groujid J'ater Development 120 Potential for Increased Ground Water Development 121 Pope Valley 123 Geoloc:- 123 Hydrology 125 Present Ground Water Development 126 Potential for Increased Grouiid Water Development 126 Capell Valley 126 Geology 12? Hydrolo;:y 123 Present Ground w'ater Development 129 Potential for Increased Gi'ound '.Jater De\"elopment 129 Suix-tar;- and Evaluation of Ground Vvater Conditions IjO CIi/'J'Ti:R V. P033IBL2 SUEFACZ 3fOPu.G:3 PIiOJ"fCT3 133 Hffect of Upstrear.i Development on Yield of I.onticcllo Reservoir . . . 13^ Inventory of Possible Dcii and Pvoser'/oir Sites I38 General Ensineerin^ Properties of Geologic Pcrmations l45 oeismicity 1^1.9 Di-^- Creek Da;.i and Peservoir I5I Middletoiai Dain and Peservolr 16I IV TABLE OF CONTEaossible surface j-eservoir sites. This would include reconnaissance geologic eval- \xations of dam sites, preliminary surveys of the Bites, and rough estimates of costs and possible reservoir yields for various volxmes of storage. "U. MaJce a reconnaissance appraisal of the ground water potential. Included would be a summary of present tises of ground water, existing well rec- ords and yields, and a geologic reconnaissance of the ground water basins. "5. Make a reconnaissance stvidy of agrictiltxiral eco- nomics in the area. %. Prepare a preliminary appraisal of local interest in water development, and the possibilities for financing and constructing water development works. "... prepare a report summarizing results of the investi- gation, with conclusions and recommendations for a subsequent course of action." The rei>ort is not intended to present a comprehensive analy- sis of all aspects of water resources problems in the l^pi>er Putah Creek Basin nor does it present a specific plan for water development. It does supply data which will aid the local people in plotting a course toward water development. Related Investigations and Reports In connection with this investigation, a review vas made of several reports and basic data of prior investigations dealing with various phases of water resotirces problems of the Upper Putah Creek Basin. A brief sunanary of the content of the reports most significant to this investigation follows. Putah Creek Cone Investigation This investigation, conducted by the California Division of Water Resoxirces commenced in September 1951* The conrpleted report, "Report to the California State Legislature on the Putah Creek Cone Investigation" was issued in December 1955. The investigation had as its principal objectives the determination of stirface and underground water svrpplies and present and future utilization of these supplies in the Putah Creek Cone Area of Solano County. With the start of con- struction of Monticello Dsun of the Solano Project by the United States Bureau of Reclamation in 1953, studies necessary for solution of the water right problems became of prime importance. These water right studies proved to be the basis for the Water Rights Board ruling which made the Imreau's permits at Monticello Reservoir subject to future ap- propriation of water for beneficial use in the Upper Putah Creek Basin. The report contsdns data on water sujyply, precipitation, runoff, emd grotind water originating in the Upper Basin and estimates of present and possible future land and water use by irrigation in the Upper Basin. Plsuas for developing additional water supplies for use in the Upper -1^. P\rtah Creek Basin vere not Included as part of the Putah Creek Cone Investigation. Investigation of Ground Water of the Lover Lake-Mlddletovn Area This Investigation, conducted by the United States Geological Survey In cooperation with the California Division of Water Resources, ccoanenced In June 1950. The completed report, "Ground Water of the Lover Lake-Mlddletovn Area, California", was published as U. S. Geo- logical Survey Water-Supply Paper 1297 In 1955. Although the larger part of the area covered by this Investigation Is located In the Cache Creek Basin, existing ground vater conditions and possibilities for In- creased development In Collayoml, Long, and Coyote Valleys near Middle- town In the Upper Putah Creek Basin are Included In the report. The results obtained from this reconnaissance Investigation vere considered preliminary because of the limited extent of developaent euad general paucity of data available at that time. State Water Rights Board Decision No. 869 This doctmient Is the official decision and restating order of the Water Rights Board regarding the U. S. Bureau of Reclamation appli- cations 11199) 12578, and 12716 to appropriate unappropriated vaters in Putah Creek at Monticello Reservoir for use in the Solano Project service area. It provides a documented history emd consideration denied by the State Water Rights Board Decision No. 869 of evidence presented at the water rights hearings on the aforementioned applications. State-Wide Water Resoiirces Investigation The State-Wide Water Resources Investigation, directed by the State Water Resources Board and conducted by the California Division of Water Resoxirces, was Initiated In 19^7 and completed In 1957* Three bulletins were published containing the resTilts of this investigation. Bulletin No. 1, "Water Resoiirces of California", published In 1951 > con- tains a conrpllatlon of data and estimates of precipitation, •uninrpaired runoff, flood flows and frequencies, and quality of water throvighout the State. Bulletin No. 2, "Water Utilization and Requirements of California", published in June 1955» includes a determination of present and probable ultimate consumptive use of suad requirements for water throughout the State. The third and concluding phase of the investi- gation was reported in Bulletin Ho. 3, "The California Water Plan", published in May 1957. This bulletin presents a comprehensive master plan to serve as a g\ilde to the full practicable development of the water resources of the State to meet future beneficial needs of the State. The relatively large projects proposed in Bulletin No. 3 for development of water for use in the Upper Basin although practicable, would probably be difficult to finance vinder present economic conditions . Other So\irees of Eata Other reports and sources of information containing valuable data on various phases of water resources problems of the Upper Putedi Creek Basin were reviewed and utilized as part of this investigation. These are listed in Appendix B, "Bibliography". -6- ( The Area eind the Problems The area under InveBtigation comprises the lands within the Putah Creek watershed above Monticello Reservoir (Lake Berryessa) . The foremost problem concerning water development that now confronts the area is the limited time available to appropriate and develop addi- tional water supplies for future needs of the area. The Area Under Investigation The Upper Putah Creek Basin is a generally mountainous ajrea of about 568 square miles. It is located in the southerly portion of Lake County and the northerly portion of Napa County. The area is about k'^ miles in length and about 20 miles in width at the widest point. The basin is bo\mded on the east and northeast by the Blue Ridge Moxintains, which also form the boundary separating Napa County from Yolo and Solano Counties. It is bounded on the south and south- west by the Howell and Mayacmas Mountains; and on the west and north- west by ridge tops that separate the Cache and Putah Creek drainage basins. Elevations along the basin rim range from 1,500 to 3>500 feet. The southwest rim is dominated by Cobb Mountain and Moimt St. Helena which reach elevations of if,722 feet and h,3kh feet, re- si)ectively. The highest point on the northeast rim is Berryessa Peak with an elevation of 3,OU6 feet. The higher elevations, principally along the west and southwesterly portion of the watershed, are covered with dense stands of conifer and white oak. The lower slopes generally support only a sparse forest of scrub pine, oak, chaparral, and -7- manzanlta. The lowest elevation In the basin is the water surface of Lake Berryessa which ranges from about 253 feet ^en empty to kkO feet when full. Putah Creek is fed by ten major and several minor tributary streams, along which are located numerous valleys comprising the culti- vable lands in the basin. The principal tributary streams entering Putah Creek frcai the north are Eticuera, Hunting, Soda, and Big Cemyon Creeks. Dry, St. Helena, Bucksnort, Butts, Pope, and Capell Creeks conprise the prtncipaJ. tributsuries draining the southerly portion of the watershed. The total irrigable area craaprises only about eight percent of the total land area in the basin. The major potential agri- cviltural areas ajre located in or near Collayomi, Long, and Coyote VaJ-leys along the upper reaches of PutsQi Creek, in Pope Valley along Pope amd Maxwell Creeks, and in Capell Valley along Cai>ell Creek. Nu- merous minor arable areas are situated along Hunting, Soda, and Butts Creeks and the lesser tributaries. The agricultural soils of the Upper Putah Creek area are quite variable. This variability is the result of the mode of foma- tion and the degree of development of the soil profiles. Three major soil groupings can be identified: recent suLluvlal soils, older allu- vial or tennce soils, and upland soils. There is an approximately equal acreage of each of the three soil groups In the area. The recent alluvial soils have the most agricultural value. Soil profiles are typically well-drained, friable, and deep enough to allow for the cultivation of all climatically adapted crops. -8- The older alluvial or terrace soils show the modification of tine which has caused the formation of rather tight euad impenetrable subsoil layers. These layei^ restrict plant root development and water movement, leaving the soil suitable for the production of only shallow root crops such as pasture, grain, and a select few truck and field crops. The third grouping is the ttpland soils. These soils gener- ally have the least agrtcultxiral value. The soil mantle was formed in place from the weathertng of the sedimentary parent rock material. Shallow soil depth and extreme relief generally restrict the crop adaptability to pasture and a few orchard crops. The climate of the Upper Putah Creek Basin is of the mild two-season pattern. A warm, dry season usually extends from May through September, with a cool, wet season from October thro\igh April. Mean seasonal precipitation varies from a minimum of about 22 inches neaLT Leike Berryessa to over 80 inches at the higher elevations. Rain- fall constitutes practically all precipitation in the area. Snowfall is rare, except at the higher elevations, and is too small to have any significant effect on the hydrologic characteristics of stream flow. Over 95 percent of the precipitation occirrs during the period from October throxigh April. The growing season is relatively long, with an estimated average of 250 days between killing frosts. The majority of runoff occurs immediately following the rain- fall but is prolonged somewhat by the accretions to streams from retain- ed soil moisture. In general, stream flow diminishes to negligible -9- amounts during the late sujnmer and fall months. HowcTer, there are numerous springs that maintain a limited flow throughout the sinmier and provide vater for domestic, stock watering, and recreational, pur- poses. In addition to Intraseasonal fluctuations, runoff has a wide annual variation, largely depending on the amount of anrmal precipita- tion. The estimated mean ftnniia.1 runoff from the Upper PuteJi Creek Basin is about 3^(8,000 acre-feet. Recent develppoent in the basin began when the first white settlers arrived about the middle of the nineteenth century. At that time the land was inhabited by Indians who lived in several of the valleys. Shortly after 19OO, tuberculosis, smallpox, and measles, rapidly wiped out most of the Indians. Development of the Upper Putah Creek Basin has progressed slowly. Farming and recreational industries are the major economic interests. In the past, the mining industry attracted prospectors and developers to the area, but today, mining plays a much lesser role in the economy of the area. Mercury produc- tion is now the most important mining industry. Agriculture was begun by the first white settlers; livestock and grain were the earliest farm products. The first record of irri- gation in the basin was reported by the U. S. Department of Agrictilture in 1912, when about 3^ acres were irrigated. After that time, devel- opment of irrigated agriculture progressed more rapidly. It was esti- mated by the Department of Water Resources that there were about 3^300 acres of Irrigated crop lands in 19^7* This acreage was reduced to about 1,800 acres in 1957, when Berryessa Valley was inundated by the -10- creation of I^ke Berryessa. During I96O about 2,600 acres were Irri- gated and dry farming took place on 5*500 acres of c\iltlvated land. Recreation development began as early as I852 when a resort was established at Harbin Spring nesir Mlddletown. In the years that followed several more mineral spring resorts were developed, principal- ly In the upper reaches of the basin and along the top of the westerly ridge. Today, changing customs and the completion of Take Benyessa have made water sports, fishing, emd hvmtlng the major attractions in the basin. Lake Berryessa lies in a beautiful, oak-studded VBlley in the foothills bordering the west side of the Sacramento Valley Just 2-1/2 hours from the San Francisco Bay area and one hour from the Sacramento Metroi»lltan area. Along the west shore of lake Berryessa about 3>700 acres of federal land are administered by Napa County under a 50-year lease from the Bureau of Reclamation. The county, in txim, has granted 20-year subleases on portions of this land for private resorts and concessions, tinder the supervision of the Lake Berryessa Park Comnisslon. The east shore of the lake is privately owned, and no public bank fishing or picnicking is permitted there. There are several resorts along the west shore. Most have a launching rBarp, marine gasoline, facilities for boat storage, a restaurant or snack bar, campsites, and picnic areas. Sane have boat and motor rentals. According to U. S. Bureau of Reclamation records, about 8ii5»000 visitor-days of use occvired at the reservoir during 1959 • However, about 70 percent of these visitors were principally sight-seers and did not use the facilities available. -11- 2. Helen Mine — an inactive qxiicksilrer mine located near the head- waters of Dry Creek. 3. An active mine in the Upper Putah Creek Basin. Merciiiy production still continues in the area. ■12- Today, the Leike Coimty portion Is the most heavily populated part of the basin vlth about 75 percent of the estimated present popu- lation of 1,200. The principal urban center Is Mlddletown, an imln- corporated consnunlty of about '*50 residents in Lake County along the upper reaches of Putah Ci^ek and its tributairLes. The estimated 300 residents in the Napa County portion of the basin are mainly located in Pope and Capell Valleys and along the vestem shoreline of Lake Berryessa. The Principal Problems In the past, growth in the Upper Putah Creek Basin has been dependent upon and limited by the development of its water resources. Future growth in the area - whether it be agrlcviltxirsJ., indvistrleJ., urban, or recreational - will continue to be dependent on development of adequate and dependable water supplies. Although the quantity of water originating in the Upper Putedi Creek Basin greatly exceeds all possible beneficial uses which may reasonably be anticipated in the basin, there are numerous problems which must be solved before addi- tional water can be developed in significant quantities. Because of its semiarid climate, the Upper Putah Creek Basin experiences natural surface water deficiencies during the summer and fall months when ralnfeLll is small and runoff is meager. This seasonal deficiency is intensified by prolonged periods of drought when both rainfall and runoff are below normal. To solve the problem of season- al and cyclic fluctuation of runoff in developing a firm and reliable source of water supply for beneficial use, significant quantities of -13- k. A concrete aggregate plant located on Putah Creek in CollayoBil Valley near Middletown. 5. Cattle grazing in Pope Valley. Here, as elsei^ere in the basin, much of the valley areas are presently \ised for range land. -lU- storage capacity are required. Stoirage capacity can be made ava.ilable by the construction of sxrrface reservoirs or throu^ the development of grovmd water. The problem is to determine ^rtiich method or ccmblnatlon of methods is most suitable. The determination of the most stdtable method or methods is dei)endent on physiceJ., economic, and legal factors. Physical factors Include water requirements, sources of water, and facilities necessary to develop the sources of water to meet the water requirements. Eco- nomic factoi*s Include the cost of constructing and operating the re- qvilred facilities, the value of water, and the meajis of securing funds to meet these costs. Legal factors Include the problem of securing adequate water rights. Adequate water rights are a necessary prereqvilsite to the construction emd operation of any water development project - whether large or Bmall - which Involves the diversion or storage of surface water for use on nonriparlan land. The recent ruling by the State Water Rights Bosurd regarding the water right permits at Montlcello Reservoir limits futvire appropriation of local water for \ise in the vipper basin above Montlcello Reservoir. The maximum amount of water to be taken by futitre appropriation is fixed by a provision that the water rights granted for the Solano Project shall be subject to a depletion of stream flow above Montlcello Resei-voir, not to exceed 33,000 acre-feet of water anniially. In addition a limitation is placed on the time available for this future appropriation. The terms of the water rights permits require that the future appropriations must be Initiated and -15- 6. Recreation deyelopnent along the vest shore of lAke Berryessa. This area has facilities for picnicking, eaoiping, and heat launch- ing and storage. ^ " V V F3^^ ■' , VV, if 7. A small itarlna on Lake Berryessa, where develppoent of recreation is steadily increasing. -16- consTaanated prior to full beneficial vise of vater from Montlcello Reservoir in the Solano Project service area. Therefore, the problems of water development in the Upper Putah Creek Basin Include the prob- lem of time available to appropriate aulditional water. The following chapters of this rejxjrt discuss the various facets of the water problems in detail and form a source of basic data. These data will be helpful to local i>eople interested in solving their water problems. -17- CHAPTER II. WATER IfTILIZATION AND REQUTRIMENTS The nature and extent of vater utilization in the Upper Putah Creek Basin at the present time and the fut\ire requirements for devel- oped water supplies are considered in this chapter. Restilts of studies conducted for the Putah Creek Cone Investigation are dravn upon heavily for estimates of present and ultimate vater requirements. However, this bulletin stresses the economic factors involved in near future water developoient and the problems Involved in securing appropriatlve water rights. In the ensvilng discussion, a clear distinction is made be- tween water utilization aind water requirements. The tenn "water util- ization" as used in this bvilletln, is defined as the consuaiption of applied water by Tegetatlve growth in transpiration and building of plant tissue, euid to water evaporated from adjacent soil. It does not include the consvmrptive use of precipitation. The term also refers to water con8\imed and evaporated by urban, recreational, and other non- vegetative types of use. The term is synonymous with "constrnqptive use of applied water". The term "water requirement", as vised in this bvilletin, refers to the amovint of water, exclusive of precipitation, needed to provide for all beneficial uses and for losses incidental to such uses. It is a measure of the eimount of water reqviired at a farmer's headgate in the case of agricultural use of water and the delivery to a water supply system to a ccomiunity, or Its equivalent, in the case of urban or recreational use. -19- Present Water Utilization At the present time, development of water resources in the Upper Putah Creek Basin is almost entirely on an individual basis. There are no public or private agencies of any appreciable size pro- viding water service. Because records of water use are not available, water utilization, in this bulletin, is evaluated using data on land \x6e and popiilation, together with estimated unit values of water xise. In the ne&r future, a more accvirate evalxiation may be possible as a restilt of data currently being collected by the department. The unit values of water use utilized in this report were taken from the "Report to the California State Legislature on Putah Creek Cone Investigation, December 1955" and results of similar studies of nearby axees. The first survey of irrigated lands in the area was made in 1911, when it was reported that 1^2 acres in the Mlddletown eurea and 65 acres in Coyote Valley were \mder irrigation* Capell Valley was aJ.80 cemvassed at that time but it had no irrigated acreage. Apparent- ly Pope Valley was not covered by the svunrey. From this beginning, irrigation Increased slowly over the years until the past decade. It appears that from 1950 to I96O the irrigated acreage more than doubled. This recent increase is due largely to developnent of ground water STipplles in the Lake County portion of the basin euid to construction of Fanall stirface reservoirs in the Napa County portion. One exception to this is the Bucksnort Creek area in Lake County which is served by Detert and McCreary Reservoirs, the largest surface storage reservoirs for local use in the. upper basin. -20- Most of the newly irrigated lands have been planted to either mixed i>asture grasses or alfalfa., although there is a large single acreage in Collaycml Valley that has been planted to a peea* orchard emd a ntnaber of smaller acreages planted to weLlnuts. Grain sorghums have been planted in several locations. Table 1 shows the present crop pattern. Plate 2, "land Use and Classification" shows the location of these lands. •21- 8, Dry-fsumed orchard and vineyard lands along the southwesterly edge of Pope Valley. t JS»^. >■ *.^ m % yjS^^:-,^:it^t\ f^ 9. Aerial vlev of a young orchard along Putah Creek illustrates full development of an irrigable area in Collaycmi Valley. -22- CO < Q o Wnll CO 2 M Q CO 2 < CO ^i: Id (d s o X O -a: 2 3 i-H a. CO w 3Du Pu OS 2 < w O Pe. voo ON CO C. £ Ji! 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"O 0) o ■P -P o 3 w 73 O C 01 O -^ O a ^ 3 OJ-^ 3 • n c o ^ -H O -P al CO M 3 n o 0) SI t.--^ OJ al C rH C al a e 01 bo •HCC -H rH^ rH OJ bO ti OJ O. 2 OJ & L. ,55 OJ 3 >> £1 73 OJ ■P al •a c 3 c n • OJ OJ CJ c al al O ^ a ^ oo u r-t 0) T3 ■P 3 3 rH O O ja - a) -H CO 4-> O 1 '^ -1 w 55 (Jl !q1o)^ Present Popttlatlon At present, the basin is sparsely populated vith only about 1,200 year-ro\md residents. About one-third of this popvilation resides in Middletown, the largest urban community. The general areal distri- bution of the present popvilation in the basin is shown in Table 2, TABLE 2 ESTIMATED PRESENT (I960) POPULATION IN UPPER POTAH CREEK BASIN Coxmty and area Laike Cotmty Middletovn Mountain recreation areas Remainder of county Subtotal Napa County Pope Valley Capell VsLLley Remainder of county Subtotal Total population Estimated present (I960) year-round population U50 180 290 920 lltO 90 70 300 1,220 Present Constmrptive Use and Water Requirements Present vater requirements for the lands shown in Table 1 are estimated to be about 8,500 acre-feet i)er year. Over 95 percent of this amotint is reqiiired for irrigated agriculture. Only about 5,900 acre-feet of the estimated 8,500 acre-foot requirement are consvmiptively used. The remaining 2,600 acre-feet appear as return flow and are -24- avB-ilable for i?e-\ise. These estimates are based on the unit values of consumptive use of applied water shown in Table 3. TABLE 3 ESTIMATED UNIT VALUES OF CONSIMPTTVE USE OF APPLIED WATER IN UPPER PUTAH CREHC BASIN (Acre-feet per acre) : Estimated average a-n miAl con- Class and type of land use ; sunrptive vise of applied water Urban and Recreational Lands Residential, ccamnercial, and rural 0.30 Recreational Irrigated AgrlcviltxireLl Lands 0.15^' Alfalfa 2.1 Mixed pasture 2.3 Pastvire and OrchaJ?d 2.3 Deciduous Orchard 2.2 Field Crops l,k Vineyard 1.1 a/ Applied to all recreational lands except sparsely populated lands surrounding Lake Berryessa where a value 0.01 acre-feet per acre was \ised. Water utilization appears to have increased during recent years. Table h shows the estimated cheuige in consuniptive use of ap- plied water durtng the 6-year period 195^-19^0. The estimated average increase in water utilization during that peiriod was about 6.0 percent per yeso". .25- TABLE h ESTIMATED AVERAGE ANNUAL CONSUMPTIVE USE OF APPLIED WATER IN UPPER PUTAH CREEK BASIN Class of land use by counties Estimated consumptive use of g_< applied vater 19^W ; i960 ; Change during 6-year period 100 1*0 1/ iTRJ 3,700 500 4,200 4,400 1,400 5,800 Urban and Recreational Lands Lake Co\inty b/ 100 c/ Napa County b/ 40 c/ Subtotals E/ iJiS c/ Irrigated Agricultural Lands Lake County 3,700 4,400 + 7OO Napa County 50O 1,400 + 90O Subtotals 4,200 5,500 + 1,600 Total change + 1,600 a/ TsJfcen from "Report to the California State Legislature on Putah Creek Cone Investigation, December 1955" • b/ Not ccMiputed. c/ Changes assumed to be negligible. Estimates of present water requirements were obtained by multiplying acreage of the various classes and types of land use, shown in Table 1, by the appropriate \init value of consvmiptive use of applied water, then dividing by the average application efficiency. For urban and recreational lands, efficiency of application was assumed to be 50 percent. For irrigated agricultural lands, efficiency was assumed to be 70 percent. Table 5 shows the result of this cranputation. Other uses of water, such as resei-voir evaporation and consumptive use from direct precipitation, are not included in these totals. Although esti- mates of urban and recreational reqviirements were computed on the basis -26- of land devoted to those purposes, a check on the basis of popiilation, using 200 gallons i)er capita per day, was made with virtually the same results. TABLE 5 RECX)NNAISSANCE ESTIMATE OF PRESENT (i960) WATER REQUIREMEOTS IN UPPER PITTAH CREEK BASIN (in acre-feet) Estimated present average sinniial water requirement • Urban and : Irrigated : recreational : agricultural : County and area lands : lands : Total Lake County Collayomi-Long Valleys area 110 2,230 2,3^0 Coyote Valley area ^1. 1,420 1,U20 Bucksnort Creek area a/ 2,250 2,250 Remainder of Leike County 100 360 1+60 Tftke County totals 210 6,260 6,U70 Napa Co\anty Pope Valley area Pope Creek area 20 570 590 Burton-Hardin Creeks area 10 530 5UO Cape 11 Valley area 20 1^30 U50 Remainder of Napa County 20 ii6o U80 Napa County totals 70 1,990 2,060 POTAH CREHC BASIN TOTALS 280 8,250 8,530 a/ Negligible. Althovigh it is known that the basin experiences deficiencies in naturail surface water supply during fall euid summer months, the mag- nitude and extent of these deficiencies are not known. However, in the ■27- near future, it may be possible to determine this deficiency from data being collected for the current Inventory of Water Resovirces and Re- qtiirement Investigation. Future Water Reqtdrements As previously stated, over 95 percent of the present water requirements in the Upper Putah Creek Basin is for irrigation of agrl- | cultviral lands. Although urbeui and recreational demands for water are \ expected to increase in the future, it is anticipated that irrigation will continue to be the primary water requirement. The future amount of water that will be developed for use in the basin will largely depend upon the capabilities of the land tinder irrigation to produce climatically adapted crops, together with the cost of developing water supplies in comparison to the net returns to be derived. For surface water development, the ability to secure ap- propriate water rights may beccane a controlling factor . Ultimately full utilization of land resources within economic limits will define the maximum potential water requirement. Land Classification Survey The capabilities of the land to suirport irrigated agriculture in the Upper Putah Creek Basin were studied In 195^ as a part of the Putah Creek Cone Investigation. Land was classified according to its irrigability and crop adaptability. The land classification procedures employed an examination of the soil characteristics and the physiography of the landscape. -38- Field mapping was done on aerial photographs having a scale of 1:20,000. Soil borings, land form characteristics, existing vege- tative cover, euid published soil survey maps were used to determine the crop adaptability, suitability, and limitations of each parcel of land delineated on the aerial photographs. Acreage determinations were made by transferring the field data from the photos to base maps, where they could be accurately meas- ured. About 28,000 acres were found to suitable for Irrigation during that sxirvey. An examination of results of similar surveys conducted in I9U7 for the State Water Resources Board, published in Bulletin No. 2, indicated that there is an additional 6U0 acres of irrigable lemd in the vicinity of Eticuera Creek. These acres were omitted in the 195^+ survey because of their close proximity to the then proposed Lake Berryessa, but have been included in this investigation. Further field examination during this Investigation revealed that in some localities certain soil characteristics which materially affect CTO-p adaptability had not been delineated in previous surveys. These were, however, delineated during this investigation. The re- vised classification and acreages, by selected areas, is sho\m in Table 6. To facilitate a study of potential service areas and aid in analysis of local water development projects these tabulations were made in more detail than in previous bulletins. The revised tabulations show about 2,800 acres of Vh lands which were formerly classified as "V-lands". Because of the reconnaissance nature of this bulletin, .29- and so as not to duplicate the detailed re-evalviation of land classification presently being conducted as part of the current Inven- tory of Water Resources and Requirements Investigation, the land clas- sification shown on Plate 2 is as mapped for previous investigations. However, full consideration is given to these changes in land classification in all pertinent sections of this bulletin. Classification symbols used in Table 6 are as follows: -30- Land Classification Standards Irrigable agricultural lands have been classified, in accord- ance with their topographic characteristics, as V, H, or M lands. V - These Icinds are level or slightly sloping and vary from smooth to hunimocky or gently undulating relief. The maximuni allowable slope is 6 percent for smooth, reasonably large-sized bodies lying in the same plane. As the relief increases and becomes more complex, lesser slopes are allowed. These lands are suitable for all cli- matically adapted crops. H - These are lands with greater slope and/or relief than those of the V class. They vary from smooth to moderately rolling or undulating relief. The maximum allowable slope is 20 percent for smooth, reasonably large-sized bodies lying in the same plane. As the relief increases and becomes more complex, lesser slopes are allowed, M - These are lands with greater slope and/or relief than those of the H class. They vary from smooth to steeply rolling or undulating relief. The maximum allowable slope is 30 percent for smooth, reasonably large-sized bodies lying in the same plane. As the re- lief increases and becomes more complex, lesser slopes are allowed. Lands identified as V, H, or M have permeable soils with medium to deep effective root zones. They are free of rock and not limited by a high water table. Variations from this pattern are in- dicated by the following subsymbols. r - Indicates the presence of rock on the surface or within the plow zone in sufficient quantity to prevent use of the land for culti- vated crops. p - Indicates shallow depth of the effective root zone, which limits use of these lands to shallow-rooted crops. h - Indicates very heavy textures, which make these lands best suited for production of shallow-rooted crops. Miscellaneous Classes N Includes all lands which fail to meet the requirements of the above classes. -31- 10. Newly constructed farm ponds in Pope Valley. Numerous small res- ervoirs such as these furnish a limited water supply for stock- wateirLng and domestic purposes. 11. Irrigable land in Pope Valley. A substsmtial augmentation of the present limited water supply is required here for development of irrigated agriculture. -32- 0) u u cd I o o a ^ 0) U (U CO ■)-> (U ^ O ■P o o p- g * oj 3 -p s o o O -P ^1 u a >4 •H Vl +> gOfl (U O K O dS 03 d) O > 0) H > Burton - Hardin Creeks area 0) & Ph Pope : Creek: area : (1) -P rH AJ g aj efl 3 +J MOO o -P u I -ri -p 05 -H o 3 i 8 iJ i 0) cd o n (U (U ^ a ^< M CO o 03 •p 0) oS O t-l 0) >,r-j tj O 03 oS o > o ^ (u a >> a H 0) 08 Q H ^1 H M 03 0) H > O O Q O Q O CO -3 «H v5 ITN CO C\J o o o o o CO OJ rovo ro OJ rOjF IS OJ o O O O o O O Q O CO OJ -5 U3 a J- o o o OJ oT Ss o o o I VD O (TO I OJ PO o o o o o u^OJ <» O OJ ir\ t— ro OJ Q O O -5 OJ t~- I o ^ I o O I •» OJ o o o I OJ I o^ o o o i-l I H OJ I CO I r- ^- I OJ o 33 O J- o OJ IS co (U m iH 03 ^1 PtJi Pi o > > > > 4J CO o o o o o o O t- Q r-i (M O On VD H -* CO O Q O O O vo s .s t— I CO o O I 1 gs J- r-l a o ON o CO OJ o\ o o o I ITS I CO CO I (S Q H 0\ o g o OJ OJ I ro o o o o o o Lr\ CO O H rH CO o o Ol Lf\ o CO o O O O O Q {^ CO qp c>

I I CO I OJ a m M t&!&: So VO OJ CO "5S CO t^ l^ OJ -* t- CO CO o o o J- o -* ON CO OJ ^ •* •* CO-4- CO H OJ CO OJ OJ >1 Ol o o o t— VO CO OJ OJ LP> •\ "^ •» CO O ro OJ OJ OJ OJ O Q O IC\^ ON OJ rH CO •v "s •* -4- H ir\ Q O O VO MD OJ ITNVO OJ •\ •* •» l/\OJ CO o o o o o o t— CTNVO •V •* -v -:t OJ t-- rH OJ CO O O O rH On O O ITNMD jTO^Jcr^ §.: o o coco OJ OJ ojS o NO LfN CO rH ^ IS 8SS CO CO OJ «V «^ *v ir\ rH t^ s ^1 ■P o ■p a aj 6 ^1 P, 0) o 4J rH 03 > -p 03 a; u o a> u Ti a a (0 (U > 0) a o u "^ . P( (U P. (1) ^ tt) fl 0) O i^ •H O tt •H 0) u u •3 (X, (U ■p u o >> (U t CO o o ■p Tt ■P >. O -P d) a Td -H o rH > ■P a OJ (u ja CO +> 01 T) ^^ 0) a> |m rH 0) a >» ^ a ■rt CO p< ■H CO 0) •H 03 4-> Xl HJ CO ■S > ^ 1 03 H X) § t^ •H a 0) a •H 3 M ^ p H •rl ^ -s t:^ OJ O CO (0 3 4-1 CO o CO tJ •H 3 TJ rH CO q a; -t-t o y • H-> 0) fl 3 ^1 o o •H X> Vl -P 03 O flj ■^ bO CO •H 0) +J +> -rt P< CO 3 4) OJ rH o > o W M H to m u V ^t O H CO U ugh Napa Valley. Therefore, the selection of representative crops for the area was lim- ited to those which could be easily transported to outside markets eind/or those which demonstrated an econcanic adveintage, or least dis- advantage, with respect to other competitive ar«as of production. For this study, pears, walnuts, wine grapes, alfalfa hay, and irrigated pastxrre were used as representative crops in establishing repayment ability of irrigated crops in the potential service areas of the basin. Farm budget analyses were developed for the foregoing irepre- sentative crops. Anticipated crop yields and prices were based on information supplied by local agricultural commissions, farm advisors, and previously developed data for nearby areas. Generally they repre- sent an average of the 5-year period 1952- I956. The use of this base pertod has been adopted as a departmental standard for agricultural studies as representative of the price-cost relationship that could be expected to prevail during a long-term project repayment period. The term "payment capacity" refers to the maximim amo\mt that an average farmer, operating an economic farm unit, can afford to pay for water for the particular crop being considered. Payment capacity is the difference between gross farm income and the total cost of pro- duction, excluding water costs, but Including labor and management costs and an equitable return on the required capital investment. Pay- ment capacity does not necessarily Infer that a farmer is willing to pay that amo\mt for irrigation water. -37- Average aimual payment capacities derived from the farm budg- et analyses ranged from a low of about $11 per acre for irrigated pas- ture to a high of about $69 per acre for pears. By applying the iinit values of vater use (listed in Table 3) with an irrigation efficiency of 70 percent, average annual payment cai)acities were estimated to range from a low of about $3 per acre-foot for irrigated pasture to a high of about $33 per acre-foot for wine grapes. Payment capacity for pears and other deciduous orchard crops would average about $20 -per acre-foot. To illustrate the advantage of raising irrigated crops in preference to dry-farmed crops and to show the complete array of pay- ment capacities for selected ]*epresentative crops, a summary of the average annual crop budget smalysis and payment capacities are present- ed in Table 8. Examination of the difference between net income from irrigated and dry-farmed crops indicates clearly the greater net income which can be obtained fron iirrigation in place of diy- farming. But, in view of the relatively low payment capacity for Irrigated pasture ($3 per acre-foot) and alfalfa ($6 per acre-foot) in relation to the expected cost of surface water development, it is doubtful if the acre- age of these crops will expand significantly in the foreseeable future. However, vineyard and deciduous orchard crops have payment capacities in excess of the expected cost of surface water development at several localities of the basin. It is possible that truck crops may be grown In the future, but these do not appear to have the relative economic advantage offered by vineyard and orchard crops. .38. Eh U: < W i) u o 05 u ft u as a m tn B u a ^ " (U -p • o § o ct) 3 § ea's'" (U CO O « " 01 3 as ^ XI -l o W ft w a 10 o O O u a CO ft o u o § s -d-fw 0^ I |0\ ON C\J ^ ^ ir\ OJ on CO u OJ I |u-\ -4 ONliA 5^r On ooko CO oto ro I loo !l^ CVJ P ^< tJ 0) 0) 0) a ^ -p C 0) 0) a ^ CO •P ^ OJ 4-> S 0) ain-i vi -p s^t: m (d aJ >Q <-\ U •>,Ci ff ^ r?° ^ ^ a) ^ h t; M fi rx M (5 o M Q > H ^ T, 01 +> ed by projects discussed in subsequent portions of this bulletin, probably will be restricted to deciduous orchard and vineyard crops. In addition to agricultural land uses, future water require- ments for dcanestlc, commercial, and recreational p\irposes must also be considered. In cases where these types of development encroach on the lirrlgable lands in the basin, the requirement computed for Irrigation of these lands shoiild be more than ample for the anticipated needs for these pxirposes. Development of these types which occvir on nonirrigable lands, such as that taking place along the westerly shore of Leike Berryessa, will have water requirements over and above those computed for the irrtgable lands. A thorough appraisal of future development and attendent water requirements for these types of development was not made dxxring this Investigation. However, in a irecent report by the Napa County Plsmning Commission, it was estimated that there are about 5,300 acres along the westerly shore of Lake Berryessa and another 3^100 acres in Capell Valley which are sviitable for residential development. It was estimated that these lands could ultimately support populations of about 29,100 and 33>600, respectively. Urban development of this mag- nitude in Capell Valley would eliminate the need for irrigation water in that valley. The cei^»inty of estimates tends to diminish as the time from which they are made lengthens. An estimate for a five year period may be expected to be fairly accurate. A projection of conditions 50 years from the date of the estimate has a probability of being much less ac- curate. However, since it is necessary to make economic analyses cover- ing the entire econcsnic life of a project, estimates as made as well as possible with the present limits of the data eind knowledge available. There is no present basis on which to estimate the length of time i>eople will live or vacation at Lake Berryessa. It seems logical to sxippose that large i>ercentage of the residents of the area will be .U2- retired. Due to the year-round availability of recreation at the lake and its proximity to Sacramento and the Ssm Francisco Bay area, it could have a great attraction to people as a second dwelling. For the most part, this type development would be used for weekend or short vacation stays, jjossibly on a year-round basis. As development proceeds in these areas, it may be possible to make a more accurate determination of the futui^e. Data presently being collected as a part of the cvirrent Inven- tory of Water Resources and Requirements Investigation may assist in this regard. A point not to be forgotten is the fact that lAke Berryessa (Monticello Reservoir) was primarily designed as a water conservation reservoir and, during a prolonged drought, is expected to have an ex- tremely long carry-over period. During such a droxi^t, the lake level would be lowered to meet the demands for water downstream. This lower- ing would cause the shore-line to recede (in some cases several miles) from the developable areas, thereby reducing the relative attractiveness of the area, sind probably Inhibiting growth. Even if the area were al- ready developed to a high degree, weekend and vacation stays probably would be reduced during an extended drought. The situation may be visualized by comparing the figures in Table 9 "Water Surface Area of Lake Berryessa at Selected Levels" with Fig\ires I euid II. Figure I shows the water levels as they would have existed from I916 to I95O if Monticello Dam had existed during those years. From I916 to 1936 the water surface elevation and surface area -43- to h^ > Hi _i IxJ O cr 3 < CO CO UJ > rr U> UJ m cr UJ UJ h- v: < < 1 _i d> u. - 1 1 : - ( 1 N, 1 UJ o 2 V> UJ i r M - i ' - f - \ - ^ "5 > _j D 0) CO UJ o o CO « ^ to ^^ uil 00 UJ < CM ill o o o s o o If) o If) o i4^:| O Ol|6 I Mt-H'TII 133d Ni NoiivA3n3 30Vdans aaivM 44 133J Nl N0liVA313 TABUE 9 WATER SURFACE AREA OF LAKE BERRYESSA AT SELECTED LEVELS Water Level : (height above : meaja sea level) : Water Surface (acres) Water Level : (height above : mean sea level) : Water Surface (acres) 185 190 1 3hO 7,172 200 Ik 350 8,799 210 50 360 10,190 220 113 370 11,1*72 230 185 380 12,631* 21*0 266 390 13,923 250I/ 391* Uoo 15, 128 260 57h Uio 16,233 270 766 1*20 17,295 280 1,0M* 1+30 18, 289 290 l,kh^ i*i*o£/ 19,290 300 2,131 1*50 20, 213 310 2,980 1+60 21,103 320 U,i68 1*70 21,909 330 5,1^38 1*80 22,682 1/ Dead storage elevation: 253 feet 2/ Spillway lip elevation: 1*1+0 feet Sotirce: U.S.B.R. Map No. Gl661*€, June 21*, 19U7 -1*5- woiild have trended downward. The lake would not have filled until early 19^+1. Figure II, which shows a cross section along the longitudinal axis of Lake Berryessa, cajinot be used to compute the horizontal water reces- sion at smy particular point on the lake during times of drought. The dis- tance between any given point ajid the water's edge for each water surface elevation depends upon the contours of the land at that point. Future Supplemental Water Requirements . Future average anniial supplemental water requii^ments necessary to fully develop all presently undeveloped irrigable lands in the selected service areas axe estimated to be about 30,000 acre-feet. However, because of the wide divergence in unit water requirements of vineyard and orchard crops, and the si)eculative nature of predicting relative amounts of each crop, this projection cannot be made with any degree of certainty. Consequently, projections of future supplemental agricultural water requirements were made on high, low, sad intermediate bases. It was considered very unlikely that all irrigable lands would be devoted exclusively to either vineyard or orchard crops. Hence, the estimated minimum supplemental requirement of about 26,000 acre-feet per year was based upon an assimied cropping pattern of 80 percent vineyard and 20 percent orchard. Similarly, the estimated maximian supplementail requirement of about 38,000 acre-feet per year was based on an assumed cropping pattern of 20 percent vineyard and 80 percent orchard. This pro- cedure establishes the probable range of the average annual supplemental water requirement to fxilly develop all presently undeveloped irrigable lands in the selected service areas. The intermediate estimate, amoionting • k6- 1 i V to about 30>000 acre-feet per year, i^presents the most likely value, considering variations in soil characteristics and present trends in development. The total average aimiial future water requirement for the selected service areas was estimated to be about 38,000 acre-feet by adding the present requirement to the estimated future supplemental re- quirement. A summary of the results of these estimates, by service areas, is presented in Table 10. However, if either Goodings aad/or Walter Springs Reservoirs were constructed as a means of developing additional water supplies for the Pope Valley Service Area, the indicated values of net irrigable area and water requirements would be further reduced, by Invindation of a portion of the irrigable lands. A review of data on file with the Water Rights Board indicates that development of additional supplies in the Bucksnort Creek area has taken place since the survey of present land use. This development probably would result in a higher present water use and requirement and correspondingly lower supplemental water requirements than shown in the table. The extent of the inundation of irrigable area and water requirements in Pope Valley and the recent development in the Bucksnort Creek area are discussed in more detail in subsequent portions of the bulletin. Table 10 does not contain an estimate of future water require- ments in the vicinity of Lake Berryessa. The difficulties and vincer- tainties in malting such ain estimate have already been discussed. The Napa Covinty Planning Commission estimated that if full, residential .k7- development of these lands were to take place, they would have an average annual water requirement exceeding 10,000 acre-feet. Over one half of this amount would be required in the Capell Valley area. Recently, in behalf of Napa County, the Bureau of Reclamation filed water right application No. 1993^ in the amount of 7,500 acre-feet per year to meet these possible future needs along the shore of the lake and in Capell Valley. In a sirpplement to the application, it was estimated that such an amount could be required for these purposes, within the next 25 years. Of the 7,500 acre-feet, about 4,000 acre- feet would be required in Capell Valley and 3,500 acre-feet would be required along the shore of the lake. It was considered likely that the demands for water along the westerly shore of the lake will increase and that they probably will reach at least 1,000 acre-feet per aiinum within the next 50 to 60 years. -k&- •s ■P ■-! T-l o -P 0) W g -p a •9 8 M 0) S •d fl -p _r 0) d) <6 d u (0 bO 0) O ^H >-l 0] a. ^! +i >> o 0) +J (U o o r-l 0) U) •H t u o o o •* •* ^ r-i ITS m o o o o Q 9. CVJ OJ o o o o o o o o o t- o ^^ 00 J- rH O o o o o o o C^ en r^ O r-l ir\ H l-l i::^ O o o Q o S VO \£) CT\ o 3 f- on r-i o o o H O ,_ O ON-* J- H t~-X» o OO vD 8.3 8 O m t— 30 O Q O O J- t- f— m iH •s •^ •• ,* CVJ rM O H OJ 133 o o o 00 CVJ C7N oO J- - o ON rokO ir\ m t-\ 9) ^ -p u; 3 0) 10 >» 4) rj 4) M aJ ►^ r-H O +? I H o •H d -P +> B >>> }i S o (U Q d >,,-i (u a CO aj r-l +^ w H ed O >i '-' > ^ y o o m 00 s o o o o 00 o o xT o 2 o o 1/N ITN o s o o o o O O o o S CVJ o o vO o o o 9 CO i-l o o o o O O CVJ o CM O O o 8 O VD ON IfN CVJ CVJ o o o <^ CVJ I o CJ\ 8^ r-lMD o m CO t~ 5 O O CM CO o o ^ 0) u > u o -p o o (I1 •H (rt U) Tl 0) >. rH « U (h > 1) 4) (II ^ 0) rH o rH Vh 1 (fl od H-> rH C) a j ." (II n (U ■J > 0) ft n (U rH rH C/J CmOi PQ y* o oJ Oi o o o CO CO O 5 o o o CO CO CO o O 00 CM o CO o CO CM ON CO CVJ XI u 10 o •> 4-1 OS tc u a a •H > Q> O -H ^^ a a o 2 "5 , W O 0) m a a o o >> S a 3 O a a o (0 o fl o •H ■P 0] •H ^1 OS > O i) ■n (U i-H •d •« (U >> a 5 t£ u o u •H m ■p 0) XI X" a3 •d 5^ §^ ^& 0) oJ > 0) (U u -d (d 0] •H 0) u O 4) k ft ■p d 4J CO 4) U ft fl O 0] XI 4J OS > a o a o •H X> 4J o •d 4) U U 4J XI HJ 4) XI -d o (0 •p a % 4) XI o H-> a % ft o rH OJ > 4) -d d CO 4> M H-> O ■ HJ O a H-> 4-1 CO w ■p •H y •H O ft O a 4) CO ft -d 9 (0 o •H CO u 4) ■P rH a o 10 tiO c -H -d o H It a) 0) > hJ o r) a 4) ^1 ft^ -p OJ d 4-< O CO 4) 3 rH cd > 4-1 O d o ■H ■p o s HJ a o t) 4J XI -P "^ "^Ql ~o1 .U9- Effect of Water Rights on TJpper Basin Development The value of vater lies in Its use. Water rtghts, as used herein, are essentially rights to the use of water smd are so recog- nized by law. Consequently, the law concerning water relates prin- cipally to the rights emd duties in its use. An important prerequisite to a water development project is the acquisition of the necessary rights to divert, store, and use the quantities of water required for the operation of that project. Natixre of Water Rights Only a small portion of California water law has been es- tablished by legislative enactment, the major portion having been established by court decisions over a period of about one htindred years. In general, water rights In California are derived from three separate doctrines; the rli)arlan doctrine, the doctrine of appropria- tion, and the doctrine of correlative rights. In many cases, these doctrines are to some extent conflicting, and water rights based thereon have been modified by court action. Riparian Rights . Riparian rights apply to surface waters and to underground waters flowing in known and definite channels. In most cases, they are paramoiint to appropriatlve rights. They are not defined in any California statute but are a modification of the common law doctrine of riparian rtghts. They have been established and up- held In California by decisions of the courts and confirmed by the provisions of Section 3, Article XIV of the State Constitution. -50- A riparian right exists by reason of ownership of land abut- ting upon a natural stream or body of water. A parcel of land loses its riparian right when it is severed from land bordering the stream unless the right is reserved for the severed parcel. A riparian right may also be lost when transferred apart from the land by grant, con- tract, or condemnation. Once lost, the riparian right can never be re- stored. A rtparlaxi right cannot be transferred for use upon another parcel of land. Although now subject to reasonable beneficial use, a ripar- ian right is neither created by use nor lost by nonuse. Priority of use does not establish priority of right, that is, one cannot claim a superior riparian right merely because he used the water first. If there is insvtfficient water for the reasonable requirements of all ri- parian owners, they must share the available supply. Water cannot be stored or withheld for prolonged periods of time to provide for a deferred use under claim of a rliJarlan right. Furthermore, a riparian right does not apply to foreign water. That is, water brought from a different watershed cannot be used under claims of riparian right. Although rlparlsm rights are known to exist in the Upper Putai Creek Basin, a determination of these rights was not made during this Investigation nor In any known previous investigation. Approprlatlve Rights . Approprlatlve rights apply to surface and to underground waters flowing in known eind definite channels, and are based on the principle that first in time is first in right. •51- If there is insufficient water to meet the needs of all appropriators , the first appropriator has exclusive right to use the water to the extent of his appropriation. Each later appropriator has a like priority with respect to other appropriators junior in time. Appropriated water may be used on or in conjunction with lands away from streams, as well as lands continguous to streams. Under an appropriative right, water may be stored during periods of high flow for subsequent use during periods of low flow. As contrasted to riparian rights, appropriative rights are established by beneficial use and may be lost by nonuse. Prior to the Water Commission Act of 191^ (California Statutes 1913 > Chapter 586, page 1012), appropriative rights coxild be acquired by simply taking and applying water to beneficial use. The priority of a right initiated prior to 18T2 related back to the date of the first substantial act toward putting water to beneficial use, provided the diversion ajid beneficial use of waters were completed with reasonable diligence. In I872, a permissive procedure for per- fecting an appropriation of water was established by the addition of Sections li+10 throvigh lk22 of the Civil Code. -Under these sections, provision was made for posting a notice of appropriation at the pro- posed point of diversion and recording a copy thereof with the County Recorder. If this statutory procedure was followed and the appro- priation was canpleted with due diligence, priority of the right dated back to the date of posting the notice of appropriation. After 18T2 the priority of an appropriator who did not comply with the Civil Code procedure was established when water was first applied to benefi- cial use. ■52- In order to nov successfully assert an approprlatlve right which was initiated prior to December 19, 191'*^^ where the validity of such right is in dispute, evidence is required of both the original appropriation and of subsequent maintenance of the right by continuous and diligent application of the water to beneficial, use. The two methods of appropriation existing prior to the effec- tive date of the Water Ccxmnission Act are no longer available. In order to now initiate an appropriative right an application must be filed with the State Water Rights Board in compliance with the provi- sions of Part 2, Division 2 of the Water Code. Neither the filing of an application nor its approval by the board will establish a valid water right. An appropriative right is created by applying the water sought to beneficieJ. xise in accordance with law and the terms smd conditions of the permit that may be issued pursuant to the application. The purpose of filing a water right ap- plication is to initiate a right to use unappropriated water eind to establish a record of such right so that its status in relation to other rights may be definitely determined. A tabiilation of active applications to appropriate water in the Upper Putah Creek Basin above Monticello Reservoir, initiated since 191^+, now on file with the State Water Rights Board, is presented in Appendix A of this bulletin. This tabulation is complete as of September I961. It supersedes a similar tabvilation shown in Appendix B of the report on the Putah Creek Cone Investigation, dated December 1955- -53- Correlative Rights to Underground Water . From a legal standpoint, there are two classes of underground waters; namely, sub- terranean streams flowing through known and definite channels, and percolating waters. Waters in the first class are regarded as identi- cal to waters occtirring in surface streams and are subject to both the riparian and appropriative doctrines. To meet this first classifica- tion, a definite vinderground stream must have characteristics similar to a surface water course such as a channel with well defined limits, a source of siipply, a measurable flow in a specific direction, eind a substantiaJ. existence. Percolating water is said to be all ground water not included in the first class and is not subject to ajjpropriation under Part 2, Division 2 of the Water Code. So far as is presently known, most ex- tractable groTind water in Upper Putah Creek Basin would fall into this latter class. Rights to percolating waters are subject to the doctrine of correlative rights. Under this doctrine, overlying land owners have equal rights to the common ground water supply for beneficial use on lands overlying the common svrpply. The vested rights of the owners to develop grovmd water for use on overlying lands are, in general, par- amount to rights obtained \mder the appropriative doctrine. Overlying rights to ground water are appvirtenant to the Isind and vested in the owner by reason of his ownership of the land. The right of each owner is equal and correlative to the rights of 8Q.1 other overlying owners. In these respects, rights to \ise of ground water are similar to ripar- ian rights pertaining to stirface waters. ~3h- Water Right Applications at Montlcello Reservoir In furtherance of the Solano Coxmty Project, the Bureau of Reclamation has filed water rights applications proposing appropria- tions from Putah Creek at the Montlcello site. Data pertinent to these applications are shown in the following tabulation: Amoxmt of Permit Application No. Ebte filed 10-29-45 second feet acre-feet per year 1,000,000 Purpose . of use^/ Status 11199 D-M-In-I-R Permit 12578 6-30-h8 900 600,000 I-D Permit 12716 9_27-i+8 116 320,000 M-In-D-R Permit 19356 if-l5-6o 1,250 1,600,000 P Pending 1993^ 1-27-61 20 7,500 M-D Pending a/ D- Domestic, I-Irrigation, M-Municipal, In-Industrial, P-Power, R-Recreational Water sought under Application No. 1993'*^ will be used for municipal and incidental uses within 10,000 net acres within 40,100 gross acres bordering Lake Beriyessa in Napa County. Water soioght tmder Application No. 19356 will be used for the generation of hydroelectric power at Montlcello Dam. Protests have been received against both ap- plications. It appears necessary for the State Water Rights Board to hold a hearing on Application 19356 before further action can be taken with respect to it. A decision following a hearing is pending with respect to Application No. 19934. Water sought under Application Nos. 11199, I2578, and I2716 is sought for use within a 440,000 acre body of land which covers all of the valley lands in Solano County, a small adjacent area in Napa -55- Coxmty, the City of Crockett in Contra Costa County, and the Davis Campus of the University of California in Yolo Coionty. On February 7, 1957 » the State Water Rights Board issued Decision No. 869 in which it ordered Applications Nos. 11199, 12578, and 12716 be approved subject to certain terms and. conditions. Item 5 pertaining to the amount of water to be appropriated by storage and Item ik pertaining to stream flow depletion above Monticello Dam read as follows: "5- The total amount of water to be appropriated by stor- age for all purposes under permits issued pursuant to Applica- tions 11199, 12578 and 12716 shall not exceed 1,600,000 acre-feet between November 1 of each year emd May 31 of the succeeding year. "l**. The permits and all rights acqiiired or to be ac- quired therevmder are and shall remain subject to depletion of stream flow above Monticello Reservoir not to exceed 33*000 acre-feet of water anniaally, by future appropriations of water for reasonable beneficial use within the watershed of Putah Creek above said reservoir; provided such future appropriations shall be initiated and consummated pursioant to law prior to full beneficial use of water within the project service area under these permits." The reservation of water for use above Monticello Dam con- tained in permits issued purs\iant to Applications Nos. 11199* 12578, euid 12716, applies to water subject to future appropriation (appro- priation after February 7* 1957) under State laws. It appears, there- fore, that in the Upper Putsih Creek Basin this reservation does not apply to riparism lands or to groxmd water being applied to beneficial use on overlying lands, or to the refilling of these groimd water ba- sins by natursil percolation. The limitations would apply to ground water tributary to Putah Creek, extracted for use on land not overlying the ground .56- water basin and to the refilling of ground water basins not tributary to Putah Greek with tributary water by artificial mecins. The State Water Rights Board has retained Jurisdiction over the permits issued to the United States for a period up to 15 years and shall prior to the end of this period, hear, review, and make further orders as may be reqviired concerning project water released for down- streeun use. Recent estimates of the Bureau of Reclamation indicate that the entire safe annual yield from Monticello Reservoir may be put to beneficial use by as early as I98O, and that all but 33,000 acre-feet of this yield may be put to \xse by 197'+. The estimated build-up of demand for water in the Solano Project Service area is depicted graph- ically in Figure 3- Assuming that the bureau's estimate accvirately defines the development rate in the Solano Project Service area, there remains from I3 to 19 years to appropriate, develop, and put to use additional local water resources which are subject to the laws of ap- propriation. Although the applications listed in Appendix A indicate that an aggregate amount approaching 26,000 acre-feet have been applied for since February J, 1957, the quantity of water actually developed and used since that time is minute compared to the 33^000 acre-feet allowed. Time is, therefore, of the essence in developing ad- ditional local water resources subject to the laws of appropriation. After full beneficial use is made of the yield from Monticello Reservoir, the right to such appropriation presumably will -57- be terminated. This does not necessarily mean that additional sup- plies could not be sectired in the future for use in the upper basin. Plans for transporting huge quantities of water from the Eel River Development through the Upper Putah Creek Basin to the Delta have been and are currently being studied. It is possible that water could be obtained from that source for use in the upper basin. However, even if Eel River water does not become available, it is possible that water could be made available for development in the upper basin through exchanges with downstream users on the valley floor. -58- riMSTEO TIME WHEN USE IN SOL )ECT SERVICE 4Re» WOULD PRO! R APPROPRIATIONS FOR UPSTREJ ES PRC FURTHE >N0 (IB.T -^ M USE ' \ SAFE ANN JAL TIELD .0 RESERVOIR CHE-FEETI \ (247,000 A MAXIMUM STR RESERVED f (33,O0C :am flow oeple or upstream u acre-feet) TION ' SE -^' / / / / / X, STIMATEO TIME SOLANO PflOJEC REA WOULD TEND ERVATION FOR UI WHEN USE T SERVICE / TO REDUCE >STREAM USE / / / / / 1 1 / / f LEGEND / / / ATER DELIVERIES WATER DELIVERIES JTED BY U S BUREAU MATIONI — - PROJECTED (AS ESTIM/ OF RECLA 1 1 1 1 1 1 j 19 S8 I960 1980 END OF YEAR ESTIMATED BUILD-UP OF DEMAND FOR WATER IN SOLANO PROJECT SERVICE AREA 59 CHAPTER III. SURFACE WATER SUPPLY The principal source of water supply in the Upper Putah Creek Basin originates from direct precipitation on the area, occxirrtng al- most entirely in the form of rainfall. The magnitude of precipitation and resultant runoff varies over a vide range throughout the area and erratically from year to year. However, there are numerous springs which maintain a limited flow throughout the summer. Small quantities of sxirface water are utilized through direct diversion of stream flow and small surface storage developments. In addition some surface water percolates to ground water bodies which are utilized to a limited ex- tent in certadn portions of the basin. There has been no importation of water to the area. Precipitation The Upper Putah Creek Basin lies within the area traversed by the southern portion of storms which sweep inland fix>m the Pacific Northwest during the winter and spring months. The precipitation from these storms varies from moderate to heavy and, due to the lifting ef- fect, generally increases with increases in land elevation. Pronounced and abrupt changes in altitude and toixjgraphy have marked effects on the quantity of precipitation. Records of Precipitation The report on the Putah Creek Cone Investigation listed six precipitation stations within the Upper Putah Creek Basin with records exceeding ten years in length and presented a isohyetal map showing the -61- estimated mean seasonsJ. depth of precipitation over the basin. Since the publication of that report, two new stations have been established near Monticello Reservoir to replace a former station. There have been no other new precipitation stations established in the basin. However, extensive investigations of precipitation were made in the adjacent areas during the recently canpleted Cache Creek Basin Investigation and the continuing North Coastal Development Investigation. Studies for these investigations supply data believed to be indicative of con- ditions in the Putsih Creek Basin. Because of the time and funds avail- able the precipitation characteristics in the basin were based on the data available from these prior investigations. Table 11 lists precipitation stations located both within the basin and on the outside slopes adjacent to the basin. Most of the stations listed have continuous records of ten years or longer. Mean conditions of water supply were assumed to be represented by the 50-year period I905-O6 - 195^-55 • Where necessary, precipitation rec- ords were extended to cover the 50-year meem i)eriod by correlation with records of nearby stations covering the longer period. I -62- CM nO O On (^OO UN_:J OO nO U\0O CTnOO CM r^ O C3\ U\ O CO CO On NO r-so no r— nO-3 •Jo 8 OO t— lArH \f\ CM r-i OJ H On_3 r^CM CO f^ nO On CVj^ CM O nO On t^ CM 1-1 o ON CM On CO r~ CM on H On On CO -3 UACM On On CO CNI 1 1 ON ON .937-38 .936-37 .908-09 .917-18 CO On ON ON .955-56 .956-59 r-i O -^ CM O On -3 rH On On L 906-07 L911-12 NO H «^ r^ UN O On On On U\ 4 I C ^ +J > O C «) 4) -H -H (B 1-1+5 o ^ ^ C5 5 6 CL, -3 CO CM <*> On On (D +3 CD > CO On 5 2: On 0) S5 c o •H CO S^ eg- « r-t rH i-t O CO O NO O to a> CM +J a> +i cd > CM Pi a I ro O I r-i On CO CO On On 0) •H U Ol, O NO UN -3 I rocjN no ro On On O O CM CO ■ri u 0^ o u\ o CM 5 o H ^ ^ to tH (4 JO CM CO I O CM Q CM 0\ On r-t H § V c c rH o O u\ o ■»> r-i e On CO _3 CM On rH CM o NO -3 UN o NO ^ CO « ro 4^ ^■3 iH J On On I I iH CM r-- On O rH CM CO CTn On On On « 4? CM CM ro U a. o UN CO CM CO 8 ro «^ CM u o OO CO CM ''"1 s s CM r-i o PS On 14 0\ 0) s- 2 On 4 I O 0) o •H o iH a> 4> 4> ca 63 n gs § X -p « ^ o a 1-1 c~- O r^ i-HsO CM r^ r-_3 r— CM -=rco UNrS f~-o •H a c ai t?s CO O UN rH \OvO -::JcO c^o\ r— no OO cry t^ c c ■W XI « • • • • • • • • • • • • • • • • -vt o VTi «^ -:f On r- CM -3 CM t^ CM t^ On OO vO CM OO vO i-i -rt C CH \0 C\J .J MD fH r^rH CM rH -CI CM rrv t^H 0) (fl -P a CO M O TJ O ^ - O +5 O rt eo -H •• •« o td a. A 0) G O -H CO C^ rH-^ O.^ CO r^ CM UN rH O CO CTn CO rH CO On « 3 to o c ■u\-^ J c^ OS CM UN UN UN UN -^ CM (*N r<^ UNr^ r^f^ V O 1 1 1 1 1 1 1 1 1 i 1 1 1 1 cic^ 1 1 T^ ^ « r-vo O r^ C\ rr\ C^vO r-t^ O CTn C~- CO W &. 0) vrv J -^ CM CO CM UN UN On 0\ UN UN _=r r-t cr\ f*N UN c^ eg CJ Os CA .^"v UN CO 0\ CTn On 0\ On CN On On c/\ On 0\ E CO rH rH r-i r-i r-t r-i r-l r-t r-t r-i r-i r^ r-i r^ rH H r-i H •• •• ••« n •• r* »• •v r-l C tH (TOO •d (u 0) XI o -u m -p t. m cs © ^ eg o cd 4J x; -P CO UN UN C^ CM O t^ rH s o C\ ^^-3 ca ci cr\ 0\ Cn CK 3^ (J\ On rH rH -3 C^ On O, a, ^i ^ rH rH r-t XI rH r-t r^ rH iH rH r^ rH ^1 W -'J M •• •• ** •* •• »• •. ^^ ^J .-» «*1 :q « » o > > > > »> .-»^ ■d -r CO 3 O O W O *5 •H -H •rt •H •r4 ■H TJ ii -4 o o « :=> W Eo a. ^4 U h h u U Q) o rs: _:: CO ^< o -i 3 CD CO Ok ^ ■■u CU (V. a. •% 5 +3 CO : : fH 1 C -P Eh lA o UN O O Q o C • '~^ ^ > O c «> s rH ■u\ ^ \A UN On rH CA UN O 0) •H -H U) CO rr\ CJ CM CM (»N rH f^ o § ^ — (H -P Ch A 5 E^ ^ .^ CO e-i M^ CT) s rH ;^ a c M •H Q E- pi :^ CJ S •? HJ LL, -P o g ^ \A r-t r-t O CM NO CM ^ ^ a; -=« f^ a. 1 CO Eh H S CO s O O vO S H £ a CO 9-^ c o a> ^ 1 CM S S < CM H ^ ^ g g g g ^ g ^ g s • • ^ ^ 5 _ 3 -3 a; s: UN O ?: z ^ 2 S s z a u m CO ;^ On O O o CM H rr\ H rH rH H r^ H ^ § ct o 4 O O C O ^ o p> rH a. H r-i r-t rH rH o et O !r O O O O - •• •z >H s J« SH >H >H >H SM J3 o CJ {^ ^ g • « •P « ^ 03 ^ ^ u\ U CO 0^ fx^ Ui. ??N :s c O ri _:» i >s Sv •H ^ > o •H V « w g (Q cd & o -3 c O. 2, &« &> ^ 5 at CJ 3 S a 1 61» ■I eg '9 = ^ g M i r oj ■: << ^ CO 3 2 f^ ~ a: £-• -. u -- £ -J ii. 3 ^ 1 ^5 p a, ri c 5-? •rl • ed +^ C CO tl «k 1 :: +3 t> C (U 0» -H -H 0) iH 4J «M w rt • • •• •• •• •• • • •• •H -P u S?^ CO § • • g c fH ^ eS a •H ■P (d ■p CO CO tvi -3\r\ 00 r— Ox CO r^ rH « C>- s ~:3 sO CSi -3^ XA 0\ OS r- -3^ vO i-i rH OS CSJ OS sO CO vOrH CO OS r^ r~- CSJ 1-1 :3 ro on ^ roco CM OJ :3 00 t^ CN ^-Os r^ c^ CM -J rH rH r- rH -3 r-t -J or 1 1 r- oo 1 1 C^OO 1 1 to 1 ?2. CO 1 1 r-os UN C\i -a f^ UN f»N _zf <*> U\<*N UN ro J f^ -3 -:3 f^ UN -3 CN OS UN OS 0\ us Os On Os Os OS CA 0\ 0\ CTs 0\ OS Os OsOs iH fH iH rH r-i r-l rH rH i-i r-i r-i rH rH rH r-{ rH r-i r-i r-ir-i C-H UN o OJ I sO Os Os r^ OD 0\ X) :=> a, so CO en O rH O I CSJ so o ■p sD c/3 S; CM CM O ■P r-\ a> f*N -P OS cd rH X3 H CM I UN f^ r^UN OS Os rH rH 'i i 8 CO Os UN 00 -::r rH e; O o so SO rH CM O ■P m -p 0\ rt rH X! « -P (It > •rl U O ^ On i o c o CO 0> 7S CM to o «' 65 rH Q> CO » »»N +> ^-3 CO 3 UN CM CM O CM o ■p o ■p C— +3 t*N -P CO nj Os r-i -O % 9 -p > ■H o sO rH I CM CM -P > •ri U a, o CM 00 ^ vO CM OO « CSJ P ON (fl rH X) •P > •rl UN UN CM 0\ CN O •P Os Q) -:3P S5 C3 u\ CM CM CI ^ a S ;2 Z •z SS m m CM CO CM CM rH rH H rH ra r-i rH t 05 c C- H H o cd 43 • g •H P. ^ J 00 a X & s «d 1 S o c -p d ■p • • •• "^ S c 1 o 8 -p c at « o »H ^ Q) •3 oi ^ Q) G c5 ••»•*• >. +> § o o c o •H ■P O 0) C/J (0 o o •H ■P c4 ■P CO O\v0 NO C\J OO C7S UN r^ I I ■g a Pi CO <; « a. D-, P^ O -3 u\ O ■P 0\ ^ \£\0 O 0\ • • O Ov CN <^ I I (7\ CO CO r>-\ OO CN 04 CVJ CVJ o -p O © CO -P CNCO lAOl • • ^S vO' vO C7\ On O ■P rH (D H -P ^?1 CO r- I I t^vO 0\ CN r-t r-i ^ O ■P CM • CVJ OV U\fH • * vOoO -3 Ooo C>\ CJ\ rH iH >o o CM CO ■LTV 5 vO O CO S5 vO «1 CVJ UN H ^ OO 0> ■p ■H o 0\ o OO o o CO a Pi O ■P a n u e> -p c C0-:J • • CVJ O U\H OsOv CVJ o -p I r-\ a) oo-rj '*\ -P roXA 0\ cS Ov OS r-i "V r-i r-i ■p > Ph o CVJ H o to e •H vO OO rH Ov J <»> CD OO Ov C^v 0\t«- 0O\A I I \A\rv Ov H • H o o • U\ -P o •p CVJ P « -p > •H a. H ■P a. o CVJ CM ^ £ o O 0\ o H I -P I 66 Characteristics of Precipitation Rainfall constitutes practically all precipitation in the area although light snowfall is not uncommon at the higher elevations of the westerly jKjrtion of the basin. Storms passing over the basin deposit their heaviest precipitation along the crest of the ridge de- fining the westerly boundary of the basin. As the storms progress eastward, depth of precipitation genera3JLy decreases with decreases in elevation xintil a minimum is reached in the vicinity of Lake BerryesSa. Once having passed over the lake, the lifting effect of the mountains forming the easterly boundary cause only a slight increase in the seasonal depth of precipitation because the productivity of most of the storms has been largely dissipated. Precipitation varies over wide limits frwn year to year. The estimated mean anniial depth of precipitation over the entire basin is about 33.5 inches, varying from a minimum of about 22 inches near Lake Berryessa to a maximum of over 80 inches at Helen Mine, located near the ridge tops between Cobb Movmtain and Mo\mt St. Helena. Over 95 percent of the anniial precipitation occurs, on the average, during the 7-month period from October through April. Estimated average monthly distribution of mean anniial precipitation at Middletown is shown in Table 12. -67- TABLE 12 ESTIMATED AVERAGE MONTHLY DISTFaBUTION OF MEAN ANNUAL PRECIPITATION AT MIDDLETOWN Month Depth of Precipitation Inches Percent of Seasonal Total Month Depth of Precipitation Inches Percent of Seasonal Total October 2.53 5.70 November 5.38 12.12 December 10.72 2I+.I3 Janxiary 8.5^ 19.21 February- 6.16 13.86 March 5.81 13.08 April 3.'*0 7.65 May 1.30 2.93 June 0.46 l.Oi^ July 0.02 O.Oi^ August .00 .00 September 0.11 0.24 TOTALS kk.kS 100.00 Runoff The major source of surface runoff within the Upper Putah Creek Basin resxilts from rainfall on the highly productive watersheds of the Mayacmas Mountains located in the upper reaches of the basin. Streams in this watershed are of three types: intermittent, ephemeral aind perennial interrupted. Intermittent streams are those which flow during prolonged periods, but not continuously. Ephemeral streams are defined as those which flow only in direct response to rainfall . Per- ennial streeuns are those which flow continuously. Perennial interrupt- ed streams sure those which have perennial reaches with intervening intermittent or ephemeral reaches. The upper reaches of Putah Creek, St. Helena Creek, Dry Creek, James Creek, Swartz Creek and Big Canyon Creek are examples of the intermittent type. Most minor tributaries are of the ephemeral type. Putah Creek is an example of the perennial interrupted type. This -68- stream contains reaches in whicl^ the flow is continuous. These reaches are typicaJ.ly in canyons through nonvater-bearing formations and are interrupted by grovmd water basins which discharge seepage flow at the lower end and which absorb stream flow by seepage into the ssjids and gravels at the upper end. Two such reaches are located in the canyon between Collayomi and Coyote Valleys and in the canyon Just below Coyote Valley, respectively. The latter case is substantiated by over 30 years of continuous record at the U.S.G.S. stream gaging station near Guenoc. Stream Gaging Stations and Records The earliest runoff records available in the Upper Putah Creek Basin were obtained in February, 190^*, when a staff gage was es- tablished by the United States Geological Survey on "Putah Creek near Guenoc". This station was maintained until July, I906, when it was discontinued. However, this station was reestablished by the instal- lation of a water- stage recorder in July of 1930 and has remained in continuous operation since that time. In September, I905, a staff gage was established on "Putah Creek at Winters" and remained in continuous operation until September, 1931. Altho\igh this station was not located in the Upper Putah Creek Basin, it provides a good indication of the total runoff originating in the basin since there are only relatively minor tributaries between the basin boundary and the location of this station. In Jxxly, 1930, a permanent gaging station equipped with a water-stage recorder was established on "Putah Creek near Winters" -69- located about 6 miles upstream from the "at Winters" station. The "near Winters" station was established to replace the "at Winters" station. More recently, stream gaging stations have been installed on tributary streams within the basin at Dry Creek near Middletown and Pope Creek near Pope Valley on May, 1959, and December, I96O, respectively. Other gating stations, although not within the Upper Puteih Creek Basin, are located in adjacent or downstream tributary watersheds and are indicative of the runoff pattern for portions of the Upper Putah Creek Basin. These include Kelsey Creek near Kelseyville, which has had a water stage recorder in continuous operation since October, 19^7 J Highland Creek near Kelseyville, which has been recording water stages since October, 195^; Adobe Creek near Kelseyville also has been recording water steiges since October, 195^; Salt Creek near Winters where a water stage recorder was in operation from October 1951 to September 195^; and Pleasants Creek near Winters where a recorder was in operation from November I95I to June 195^. Locations of the stations in the basin are shown on Plate 3, "Locations of Wells Canvassed", and pertinent data for these stations are listed in Table 13 . -70- PQ W o o El cc o w s o M Eh CO O < en a; •O 1 y t« ti Vh o d o y O 0) CO Vi -d u o V (U Ih <« o -c) o •H u 0} Oi 0) a tlO -H 0) •H aJ 3 rH 0) o; o* -H ^ ^< w B Q ctf 0) w a Oj cc ^ 1 o C P< •H 3 -H +5 O XI 05 Eh w y 3 .. . . Cl o •<-< +J y a +> (0 -d a a i 0) ^^ +» c/ D ^ CO o H u a 0) id u o 8 s > 8 CO g 8 B B 8 8 •> J- MD l/N -:t O C7N in OS r-l ON H ^ H >> (U ^ H XI t— 3 •-5 OJ -p H O ■p ^4 ■p 03 ro o o o o +J -3 ja o -d IfN On -p +J +j +J +> ■p Q R rH r-i VO O t~- -^ J- rH LTN o OnO o\ +> rH ^ ^ ITN ITN l/^ ON -p H OO r-t 0) On C7N CJN o\ rH 0\ O (h ^ i-\ H rH H On &• iH U m (U 1 ^1 u^ > fi H e -P V (U V (D XI H s H e 0) Qi x> fi XI X> a 3 0) >> +> (U o O o O (U ^ ,Q ►^ y -3 •-3 P(CO -p ■P ■p +> > 1 a CO y O y o y O y o O ^^ -* t^ ^^ CO CVJ Co' C\J 00 b- J- r- CVJ VO o vd r^ r- t^ ro on H H H H lf\ VO ^ >g 5 ^ 3 ^ ^ ^ ^ ^ s B s B S s s s s s C) H On 00 CO oo PO OJ ON h- rH rH rH rH •-{ ?^ y o a V ■n a u o3 a (U (U u o •3 3 CO rH a> 03 > o a. ^^ OS a (U 3 (A ^1 (U HJ d 03 (U 0) XI 03 -4- 1 a; ID r-{ 05 -P •H CO Q -d -P v»v>v<'Vk^jffiF^ OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP RELATIONSHIP BETWEEN THE AVERAGE OCCURRENCE OF PRECIPITATION, RUNOFF, AND IRRIGATION DEMAND 76 TABI£ 15 RECORDED AND ESTIMATED NATURAL ANNUAL RUNOFF OF PUT AH CREEK ORIGINATING IN THE UPPER POTAH CREEK BASIN (in acre-feet) Water Recorded runoff Estimated natural runoff near Water Recorded runoff Estimated natural Near : At Near At runoff near year Winters : Winters Winters year Winters : Winters Winters 1905-06 -07 -08 -09 -10 582, 600 690,800 199, '^o 881, 200 227,700 560, 900 656, 500 203,800 823,800 231, 800 1930-31 -32 -33 -34 -35 34, 800 30, 200 200,700 94, 600 145, 500 352, 300 38,700 205, 600 100, 000 l49, 900 357,700 1910-11 ^ -12 -13 -Ik -15 492,800 59,200 133, 500 895, 300 709,700 481, 200 65, 000 139, 400 835,900 672, 300 1935-36 -37 .38 -39 -40 346, 500 280, 000 853,400 4l,600 674, 700 351,400 285, 400 860, 200 45,700 683,800 1915-16 -17 -18 -19 -20 708, 800 28i+, 400 88, 800 315, 500 42, 500 672, 200 288, 300 97,100 318, 500 51, 000 1940-41 -42 -43 -44 -45 1, 004, 000 715, 200 319, 400 178, 200 206, 500 1, Oil, 200 722, 600 325, 400 184, 300 213, 900 1920-21 -22 -23 -2k -25 509, 200 230, 200 278, 200 38, 600 348, 400 501, 000 236,000 283,700 47, 500 351, 500 1945-I+5 -47 -48 -49 -50 261,700 129, 400 133, 300 192, 100 182, 100 269, 200 137, 000 l4o, 800 199, 800 189, 600 1925-26 -27 -28 -29 -30 347,900 544, 200 300, 500 66, 300 322, 000 350,200 1950-51 531,700 -52 303,300 -53 75,600 -54 326,600 -55 Average for period of record 388, 000 588, 000 423, 400 284, 200 92,800 396,800 596, 800 431, 200 295, 300 99,100 324, 900 358, 800 50-year mean 347, 900 -77- FIGURE 5 ,000,000 9 8 7 6 5 S I- < 100,000 9 8 7 6 5 O 10,000 / y / y INTERMEDIATE RUNOFF EXCEEDS PERCOLATION LOSS ' A y > r / / A / <^ / /, /< / / // / / // V ^ w / 1— — P! :rc( 3LA tic N LOSSES EXCEED INTERME 3IATE RUNOFF c /V ^193 0-31 (YE :ar = ( )VERLAPPING RE( ;ORD) f 10,000 2 3 4 56789 100,000 2 3 456789 1,000,000 ANNUAL RECORDED RUNOFF OF PUTAH CREEK NEAR WINTERS, IN ACRE-FEET ESTIMATED RELATIONSHIP BETWEEN RUNOFF OF PUTAH CREEK NEAR WINTERS AND PUTAH CREEK AT WINTERS 78 TABI£ 16 RECORDED AND ESTIMATED NATURAL ANNUAL RUNOFF OF PUTAH CREEK NEAR GUENOC (in acre -feet) Water Runoff . Water =_ year • Runoff year • Recorded ^ Estimated : : natural : Recorded Estimated natural I90I+-04 22lt, 000 ♦ 1905-06 -07 -08 -09 -10 263, 000 263, 100 248,1+00 98, 200 297,900 108,800 1930-31 -32 -33 -3k -35 23, 500 83, 100 51,800 78, 600 ll+l, 500 2I+, 700 81+, 500 53,200 80,100 II+3, 200 1910-11 -12 -13 -Ik -15 19U, Uoo 38,Uoo 72,1+00 301, 900 253, too 1935-36 -37 -38 -39 -ko 157, 900 109,700 337,800 26,1+00 2I+2, 700 159, too 111, 500 339,800 28, 000 2I+5, 200 1915-16 -17 -18 -19 -20 253,500 129, 500 5^ 300 Ito, 100 31,000 19U0-I+1 -1+2 -k3 -kk -1+5 320, 900 261, 600 131, 900 81, 300 95, 300 323,1+00 263,800 133,700 83, 100 97,500 1920-21 -22 -23 -2k -25 200, 900 110, 1+00 127,800 28, 600 151,300 191+5-^ -1^7 -1+8 -k9 -50 116,800 79, 100 85,1+00 95, too 85, 600 119, 300 81,1+00 87, 600 97,800 87,900 1925-26 -27 -28 -29 -30 151, 100 210, 500 13l+,70O 1+1+, 300 11+2,800 1950-51 -52 -53 -3k -55 173, 600 222, 000 185, 200 13U, too 60, 500 176, 600 22I+, 300 187,600 136, 500 62,600 Average of re for period cord 11+3, 300 50-year mean II+I+, 1+00 ♦Not included as part of 50-year mean period. -79- annual natural nmoff of 3^7 > 900 acre-feet originating in the Upper Putah Creek Basin, although the drainage area tributary to this station is only about 20 percent of the total area. These natural flow studies, together with records of runoff at the short-term stations in sjid adja- cent to the basin and studies of rainfall- nmoff relationships provided the basis for estimating sxxrface inflow to and potential annual yield from the possible reservoir sites discussed in a later portion of this bulletin. Flood Flows No significant flooding problems exist on any of the streams tributary to Putah Creek in the irpper basin. Minor remedial measures to prevent flood damage have been limited to bank protection and channel construction works, principally on Dry and St. Helena C]*eeks near the town of Middletown. The gravel channels which traverse the valleys contain no improvements and no improvements of major valvie in the lim- ited areas of flooding are expected to occ\ir in the futvire. Therefore, since there appears to be no need for flood control meastires, such fea- tures were not included as a project function for any of the surface storage sites investigated. However, in order to determine required spillway capacities and freeboard allowances for all the reservoirs considered, studies were made of the magnitudes of the maximum probable floods that could occur at each site. The probable maximum flood is defined as the flood that would result from the most critical combination of precipitation distribution, snowmelt, and infiltration losses that would probably occur within a -80- particular hydrologic region under present climatic conditions. Flood hydrographs were derived using the estimated 72-hour maximxan probable precipitation, and unit hydrographs developed for gaged areas in amd adjacent to the basin. Loss rates were based on data from similar studies previously made for adjacent areas. It was assumed that spillways should be large enoxigh to pass the maximum probable flood without over- topping the dam. This require- ment was satisfied by routing studies in which nominal allowamces for total and residvial freeboard were included. Water Quality The quality of water may be defined as the characteristics of water affecting its suitability for beneficial use. Because of the reconnaisssmce nature of this investigation and the availability of water quality data smd findings contained in the report on the Putah Creek Cone Investigation, no new water quality data were developed for this investigation. A brief summary of these water qxiality findings is contained in this bvilletin. General Water Quality Conditions Surface waters in the Upper Putah Creek Basin are predominat- ely magnesium-bicarbonate in character and suitable for all beneficial purposes. Analyses of 19 surface water samples showed that the mineral quality of all streams sampled improved with increase in rate of dis- charge. The analyses also indicated that mineral quality in streams in the upper reaches of the basin, above the principal potential places -81- of use, is superior to that in the lower reaches of the basin. This is due to the lesser dilution of rainfall with the more mineralized base flows of lower tributaries which, in general, have a smaller total \init runoff. Water Quality Problems The most general and widespread water quality problem of domestic users appears to be excessive hardness. This is principally due to calciijm and magnesium which results in increased soap consump- tion, more frequent repairs to plumbing, and the necessity or desir- ability of maintaining water softening appliances. The effect of hard- ness on soap consumption can be somewhat overcome by use of synthetic detergents . In some local areas boron concentrations are very high, maki ng the water unsiiitable for irrigation on all except the most tol- erant crops. This condition is most pronounced dxiring low flows of Soda Creek, and in significant quantities in moderate flows of Eticuera and Capell Creeks. Surface storage reservoirs would tend to reduce these con- centrations by mixing and diluting the more mineralized low flows with the better quality rainfall-fed high flows. However, at such time as a specific project is selected for development, additional water samples at the selected site should be collected and analyzed for both high and low flow conditions. If tailings from mining operations exist in the watershed above the selected site and the developed supply is to be used for domestic purposes, the analyses of water samples for heavy metals should be included. -82- CHAPTEE IV. GROUND WATER POTENTIAL Ground water reservoirs provide for natural regulation of available water resources. They also may convey water from places of recharge to widely dispersed places of extractions, gind thereby make water accessible over a wide area. When geologic and hydrologic con- ditions are favorable, development of a ground water supply can have several advantages over developnent of a surface water supply. Some of the most common advantages are: (l) readily available storage capa- city susceptible to staged development; (2) relatively low initial capital investment; and (3) elimination or reduction of the need for distribution facilities. Development of groiind water in the Upper Putah Creek Basin may also have some legal advantage over surface water development. The right of a landowner to develop water from a ground water supply for reasonable beneficial use on overlying land is not derived by ap- propriation. These rights are similar to riparian rights smd are para- mount to the appropriative rights issued to the Bureau of Reclamation for operation of the Solano Project. For this reason, the quantitative and time limitations on future appropriations of water for upstream use, as set forth in the terms of the bureau's water right permits, are not applicable to such ground water development. It should be understood, however, that the water right ad- vantage of ground water development is subject to the following limita- tions: (l) extracted ground water is subject to reasonable beneficial uses on overlying land; (2) water withdrawn from a ground water supply -83- tributary to Putah Creek for use on nonoverlyiiig land is subject to zhe limitations in the bureau's water right permits; (3) recharge of the ground vater supply is limited to natural infiltration and percolation of surface waters; and (k) artificial recharge of the ground water supply by percolation, facilitated by teic>orary storage of surface water in spreading basins, would constitute an appropriation of water subject to the jurisdiction of the State Water Rights Board. For these reasons, the advantages of ground water development are limited to landowners where the many conditions favorable to ground water development are satisfied. Studies of the ground water potential in the Upper Putah Creek Basin included a reconnaissance appraisal of factors which affect ground water occurrence, movement, utilization, and recharge. The geo- logic investigations included the collection, compilation, emd inter- pretation of existing well drillers' logs, published and unpublished geologic reports and maps, and the determination of location, extent, and physical characteristics, of water-bearing deposits in the area. The study of ground water utilization was limited to the principal al- luvial valleys. About 210 wells were located during this investigation. These are shown on Plate 3, "Locations of Wells Canvassed". Data col- lected on these wells included pump tests, type and size of pumping plant equijment, diameter and depth of casing, principal use and age of well, and ownership. Measurements were made of depth to water in 123 and lUU wells in the fall of I96O and the spring of I96I, respec- tively. The study of ground water recharge in the major valley areas included several instsmtaneous stream flow measurements to determine -81^- infiltration rates for various reaches of sti^aun channels and em anal- ysis of water level and well log data to estimate change in ground water storage during the winter of 196O-6I. Reliable estimates of cost of developing additional supplies from planned operation of ground water storage could not be determined from available data. Although it is fairly easy to estimate the cost of a well equipped with a pimp and motor, it is not possible to predict in advance, with any degree of certainty, the yield obtainable from a prospective well. Nor is it known how many dry holes might have to be drilled for every good producing well obtained. Cost comparisons of groiind water versus surface water development covild not, therefore, be made. Occiirrence of Ground Water Most of the materials that comprise the earth's svirface have open spaces which may contain water. These spaces range in size from minute pores in clays to large fractures auid joints found in crystalline aJid consolidated sedJlmentary rocks. Depending • ijpon the distribution a-Qd size of such openings, the movement and volume of ground water may vary from near zero to high values. Ground water, by definition, refers only to that water which occurs below the water table, within the zone of saturation. Within this zone all the open spaces in subsurface materisils are filled with ground water. Nearly all ground water is derived initially from precipitation. -85- Ground water may be either unconfined or confined. When the upper surface of the zone of saturation forms a water table under at- mospheric pressure, ground water is said to be unconfined. Under this condition, changes in volume of stored ground water cause the water table to rise and fall. Ground water contained in a saturated aquifer directly overlain by sediments of markedly less permeability is said to be confined ground water. Where water is confined the rise and fall of water levels in wells represent changes in pressure within the aqui- fer. Since the ability of a porous material to transmit water is rela- tive, confinement is also relative. Geology A knowledge of the geology of the area is the key to under- standing present ground water conditions and the possibilities for fiirther development of ground water in the Upper Putah Creek Basin. Figure 6, "Looking Back In Geologic Time", presents an illustration of the various components of geologic time. The largest time unit is the era. The three principal eras are the Cenozoic (the most recent), the Mesozoic, and the Paleozoic. All of the rocks and sediments which make up the land forms in the Upper Putah Creek Basin were deposited during the Mesozoic and Cenozoic eras. An era is divided into periods, which are further subdivided into epochs, as shown in Figure 6. The table shows a stratigraphic column of the rocks and sedi- ments in the Upper Putah Creek Basin. In this colimin, all of the geo- logic units are stacked on top of each other in ascending chronologic order. The relative age and thickness of each formation may be ascertained, as -86- well as a brief description of the physical and water-bearing proper- ties of each formation. The areal extent of these formations is shown on Plate h, "Regional Geology". The UpF>er Putah Creek Basin lies in the midst of the Coast Ranges geomorphic province. The basin has been carved into a bedrock complex composed of nonwater- bearing marine Mesozoic and early Cenozoic sedimentary and metamorphic rocks which have been intruded locally by basic igneous rocks. All of these rocks are capped locally by water- bearing Cenozoic volcanic and sedimentary rocks. The Mesozoic rocks are represented by the Franciscan-Knoxville groups and the undifferen- tiated Cretaceous sediments. The Martinez and Cache formations and the Sonoma and Clear Lake volcanics compose the bulk of the Cenozoic rocks. Recent alluvium, terrace deposits, and landslide debris occiir locally. In general, the Franciscan-Knoxville groups, the Cretaceous sediments, and the Martinez formation are complexly folded and often faulted. Extensive masses of serpentine occur along the fault zones in the Franciscan-Knoxville rocks. The other geologic formations generally are only slightly deformed. The rock units were briefly studied to ascertain their water- bearing properties. In the following paragraphs, the units are described briefly and a generalized statement of their hydrologlc properties is made. The nonwater-bearlng formations are descrtbed first. -87- FIGURE 6 88 GEOLOGIC FORMATIONS IN UPPER PUTAH CREEK BASIN GEOLOGIC AGE FORMATION STRATIGRAPHY AND SYMBOL USED ON GEOLOGIC MAP APPROXIMATE THICKNESS IN FEET PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS o LANDSLIDES 0-100 UNSTABLE MIXTURE OF ROCK AND SOIL UOOERATELY PERMEABLE PROVIDES SMALL AMOUNTS OF XATER TO SPRINGS UNCONSOLIDATED TO SEMI^ONSOLIDATED SAW) AM) SILT WITH LENSES OF CLAY Ut> GRAVEL, MAY CONTAIN CEMENTED ZONES AND ORGANIC MUCK FOUND ONLY IN VAL- LEY AREAS PERMEABILITY RANGES FROM POOR TO GOOD. MAY CONTAIN ZONES OF CONFIKD WATER. Clear lake volcanics £ B S u S VARIABLY FRACTURED DACITIC. RMY- OLITIC, AND ANOESITIC LAVAS OF MT. SIEGLER. COBB MT , BOCGS MT AND PERINI HILL. YIELDS MODERATE OUANTITIES OF WATER TO WELLS AND SPRINGS. ^^ HIGHLY FRACTURED FLOWS OF OLIVINE BASALT. UNIT AS A WHOLE HIGHLY PERMEABLE IF SITUATED IN ZONE OF SATURATION. WILL YIELD LARGE AMOUNTS OF WATER TO WELLS- ACTS AS FOREBAY FOR GROUND WATER RECHARGE. ^^i:5g?r COARSE TO FINE GRAINED SANDY RHY- OLITE TUFF LOW PERMEABILITY. YIELDS SOME WATER TO SPRINGS. * •.» -.V < ■» • s « • a *« V CACHE FORMATION TQc 300-l,000« SEMI -CONSOLIDATED CONTINENTAL DEPOS- ITS OF GRAVEL. SILT, AND CLAY, SOME TUFF ACEOUS DEPOSITS. INTERBEDDED BASALT FLOWS AT TOP. MODERATELY PERMEABLE, MAY YIELD SMALL TO FAIR AMOUNTS OF WATER TO WELLS AND SPRINGS SONOMA VOLCANICS MARTINEZ FORMATION FLOWS OF ANOESITE AND RHYOLITE WITH INTERBEDS OF SANDY TUFF AND MUD FLOWS. GENERALLY OF LOW PERMEABILITY SOME SANDY TUFFS YIELD GOOD QUANT- ITIES OF WATER TOWELLS AND SPRINGS MARINE SHALE, CONGLOMERATE, AND SANDSTONE NONWATER-BEARING. CRETACEOUS SEDIMENTS, UNDIFFERENTIATED 10,000- 1 9,000 MARINE SANDSTONE AND MUOSTONE. aip : BLOCKS OF DEIRITAL SERPENTINE IN MATRIX OF CRUSHED SERPENTINE AND SHALE NONWAIER-BEARING. NONWATER-BEARING FRANCISCAN- KNOXVILLE GROUPS. UNOlFFEHtNTlATEO IS;DO0* Jft ■ MARINE SHALE. GRAYWACKE, CONGLOM- ERATE, AND CHERT. GREEN TO BLACK SERPENTINE, PARTLY SHEARED AND CRUSHED CONTAINS VEINS OF WHITE MAGNESITE AND CRY STALSOF BLACK CHROMITE. GREENSTONE DERIVED FROM BASIC FLOWS AND PYROCLASTICS Jl>- BLACK, PARTLY METAMORPHOSED BASALT. Id.: GLOUCOPHANE, ACTINOLITE, AND CHLO- RITE SCHIST Jbl BLACK TO GRAY GABBRO AND DIABASE NONWATER-BEARING. GENERALLY NONWATER-BEARING. MAY YIELD SMALL AMOUNTS OF WATER HIGH IN MAGNESIA. NONWATER-BEARING. NONWATER-BEARING NONWATER-BEARING 89 Frapclscem-Knoxville Groups . The Franciscan group of Jxirassic-Cretaceous age is the oldest rock unit in the basin. The rocks are principally a type of sandstone called graywacke bxrt include a moderate proportion of interbedded shale; lesser amovmts of chert and conglcsnerate occur in some areas. Locally these marine sediments have been intruded by serpentine. Zones of shearing and hydrothennal alter- ation are ntmerous, so that a considerable part of the sediments are sheared or contorted and contain zones of schist. The Knoxvllle group overlies the Franciscan group, and con- sists primarily of shale, which occurs in a ratio of about U:l to the interbedded graywacke; conglomerate beds occur locally. The Knoxville group, like the Frajiciscan, is intruded by serpentine and occasionally by greenstone, but shearing of the beds is less common. The Franciscan and Knoxville gro\ips have been intruded by various types of basic and ultrabasic rocks. Serpentine is the most abundant of the ultrabasic intrusives, cropping out as great irregular bodies elongated in the direction of regional strike. The serpentine is generally green to greenish-black, fine-grained and ranges from hard to soft. It is generally incompetent and is frequently intensely sheared. Small intrusions of gabbro, diabase, and greenstone also occxir. In general, the sedimentary rocks of the Franciscan-Knoxville groups have low permeabilities £ind thus are considered nonwater- bearing. Limited amounts of water, however, may occur in fractures and joints, particularly at shallow depths. The basic and ultrabasic .90- intrusives are also considered to be nonwater-bearlng except along fractures and shear zones. Some ground water, usxially high in magnesia, may be derived from the serpentine. Cretaceous Sediments, Undifferentiated . A thick succession of massive, yellovish-brown to gray, marine sauidstone and interbedded gray shale overlies the Knoxville rocks. These sediments belong to the Shasta and Chico groups of Cretaceous age. The sandstone is generally- fine to medium grained with a silty matrix in beds as thick as 15 feet. The shale and mudstone are gray to grayish-brown; and fairly soft. Local deposits of conglomerate, detrital serpentine, and limestone are scattered throughout the Cretaceous section. Almost all of the rocks of Cretaceous age are nonwater-bearing. However, as in the Franciscan- Knoxville groups, some grotind water may occur in fractures and joints, particiilarly at shallow depths. In a d d ition to the normal sedimentary materials, areas of detrital serpentine occur in Pope Valley, in Long Valley, and along Putah Creek north of Middletown. It has been postulated that dur- ing Cretaceous time landslides derived from submerged Jurassic serpen- tine bodies moved out onto the sea floor. These landslides were later covered by sediments and today appear as bodies of detirital serpentine enclosed by Cretaceous sediments. On close examination, the masses can be seen to be composed of blocks of serpentine in a matrix of crushed serpentine and black shale. -91- Martinez Formation . The oldest Tertiary rocks In the area are the marine sediments of the Martinez formation of Paleocene age. The formation is coorposed of sandstone, conglomerate and minor amounts of shale. The sandstone is white euad yellow to brown and gray and is often very massive. A light gray silty shale and a poorly sorted con- glomerate occur in the upper portion of the formation. Like the older marine sediments, the Martinez formation is nonwater-bearing. It may yield very minor amo\ints of water from Joints and fractures. Sonoma Volcanics . The volcanic rocks which occur ailong the western border of the Upper Putah Creek Basin are a part of the Sonoma volcanics of Pliocene age. These are the oldest and thickest volcanic rocks in the area, and are believed to achieve a thickness of over 2,000 feet. The dcaninant rock types are light gray andesites and rhyolites which occur as flows, tuffs, tuff -breccias and agglcanerates . The Sonoma volcauiics are partially water-bearing. In some places, the interbedded seuidy tttffs are fairly permeable. The agglom- erate and tuff -breccias are believed to be of minor importance to groimd water storage or movement. Cache Formation . The Cache formation of Plio-Pleistocene age consists of fresh-water deposits of gravel and silt which, in seme places, underlie lava caps. Outcrops of this formation are generally light gray or yellow brown. The \mit is composed of poorly consolidated .92- gravel, silt, seind, and lesser amounts of water-laid tviff , limestone, and diatomite. In general, most of the rocks in the Cache formation have low IJermeabilities except for occasional gravel and sand beds. Some wells penetrate the formation and produce moderate qiiantities of water. Tuff . A thin bed of rhyolite tuff overlies the sediments of the Cache formation. The tuff usvially occurs Just beneath a cover of overlying basalt. It is of low permeability and is of little importance to ground water. Clear Lake Volcanics, Basalt Member . Extensive flows of olivine basalt of Pleistocene a^e cap many of the hills in the Upper Putah Creek Basin. These flows are highly fractiired and have a fairly high permeability. In a few places the basalt occurs at or beneath the level of various valley floors. Here, it is within the zone of satxira- tdon and should provide abundant quantities of water to wells. Some of the basalt flows are interbedded with the uppermost sediments of the Cache formation. Clear Lake Volcanics. Rhyolite flows and tuffs, and andesitic and dacitic lavas comprise the vtpper part of the Clear Lake volcanic series. The lavas are of Pleistocene to Recent age and were apparently extruded from a system of northwest-trending fissures. The lava and frsigmental volcanic rocks may absorb appreciable quantities of precipitation and store it in Joints and fractures. Sur- plus gro\ind water emerges as small spilngs from open fractures or at the -93- top of Impermeable zones. Because it generally underlies rough, \antil- lable land, very little ground water develoiment has occun*ed in this \mit. Alluvivm i. Unconsolidated to semi -consolidated alluvimn occurs extensively in the larger valleys and as narrow, sinuous deposits along streams and creeks. The alluvium may be subdivided into stream, flood- plain, lacustrine, euad colluvial deposits. The stream deposits consist of angular to roimded cobbles, gravel, and sand, and are the best water producing zones in the alluvixm. However, due to their local and irregular occurrence, these are general- ly encountered only by chance when drilling for water. The flood plain deposits generally occur between the stream deposits and the colluvium and consist of fine-grained sand, silt, and. clay. !niese materials are generally more extensive than the stream deposits in occvirrence but, in general, have low permeabilities. The lacustrtne deposits are found in Collayomi, Long, and Coyote Valleys; they also occur locally in other valleys. These sedi- ments were deposited during periods when the valleys were invindated by fresh water lakes. They are generally fine-grained sand, silt, and blue clay, all of low permeability, but include some fine sand. Lacustrine deposits extend over large portions of the valleys often overlying more permeable units. Due to the low permeability and placement of these deposits, they often act as confining layers to the underlying more pervious deposits, resulting in pressure conditions. -9U- The colluvium, which is not an alluvial deposit in the strict sense, occurs near the margins of the valleys. This weathered material moved downslope, primarily by the force of gravity. Most colluviaJ. material which reached the valley floor is so fine-grained as to be nearly impervious. With few exceptions, the stream deposits are the only impor- tant water beeiring zones in the alluviiom in the Upper Putah Creek Basin. The other alluvial deposits are comprised of relatively fine-grained sediments which yield only small quantities of water. Well production in the alluvium is quite variable and depends on the composition and thickness of the sediments. Thus, if large quantities of ground water are required, it is generally essential that buried stream gravels which lie below the water table be penetrated. Landslides . Landslides are common throughout the area of in- vestigation. They can be easily recognized by their topographic expres- sion £ind broken rock masses. Serpentine appears to be particularly susceptible to the development of landslides. The lava flows of the Clear Lake volcanics are nearly everywhere skirted by talus slopes, or by a mantle of weathered lava and scattered boulders. Small springs and seeps are commonly associated with the landslide debris. However, the storage capacity of this material is quite limited and is of minor im- portance in supplying usable quantities of ground water. -95- -^ * 4 ■C**-;.!* •.'^-;V . • *s -I *, Jt • t ■ ■ 1^. Sediments of the Cache formation are conrposed of beds of auigular gravel and silt. The low sand content accounts for the low over- all permeability of the unit. 15. Stream channels such as Dry Creek in Collayomi VsQ-ley are composed of loose sand and gravel and allow ground water recharge from stream flow. Deposits such as these, where buried, will provide abiindant qviantities of ground water to wells. .96. Water -Yielding Capacities of Allvtvlal Materials Because the alluviiim, with few exceptions, is the only impor- tant water-bearing unit in the Upper Putah Creek Basin, its water- yielding properties should be considered in detail. One indication of the ground water potential of the alluvium is its average specific yield. Specific yield is the ratio of the volume of water which a sat- urated material will yield by gravity to its toteJ. volume. Fine-grained materieLLs such as clay and silt have a lower specific yield than cosa-ser materials such as sand and gravel. The specific yield of the water- bearing materials in the Upper Putah Creek Basin was estimated from auaalysis of existing well drillers' logs. All basin sediments were divided into five general catagories. Table l8 contains a summary of specific yield values assigned to each category. Maximum theoreticauL quantities of extractable water, or stor- age capacity may be developed from these values of specific yield. This was done by tfidting the weighted average of slLI of the unit specific yields and multiplying by the total volume of sediments in the valley. Table 19 presents the average specific yield and estimated ground water storage capacity for each of the major valleys. -97- TABLE 18 ASSIGNED VALUES OF SPECIFIC YIELD OF MATERIAIS PENETRATED BY WELIS IN UPPER PUTAH CREEK BASIN Assigned specific yield, in percent Description of typical materials encoimtered in wells Clayey soil, mud, cle^^, hardpan, tightly cemented gravel and clay, fractvired bedrock, and related fine-grained deposits. Conglomerate, sandy clay, cemented sand, loam, cemented gravel and boulders, and related deposits. 10 Silty sand, fine sand and gravel, dirty gravel, inter- bedded clay and gravel, smd related deposits. 20 Sand. 25 Sand and gravel, coarse gravel, bo\ilders and gravel, and boulders . TABLE 19 ESTIMATED AVERAGE SPECIFIC YIELD AND GROUND WATER STORAGE CAPACITY OF SELECTED VALLEY FILL AREAS IN UPPER PUTAH CREHC BASIN : Average : Estimated ground water Valley specific yield. : storage cai>acity. in percent : in acre-feet Collayomi 6.5) 37,000 Long k.5) Coyote 10.0 27,000» Pope 3.0 7,000 Capell 3.0 700 * storage capacity of depth interval from 10 to 100 feet. Total depth of alluvixim is not known. -98- Movement, Replenishment, and Depletion of Ground Water The rate of groxmd water movement In a water-beairLng material is governed by Its permeability and Its differential head. The perme- ability of a material is its capacity for transmitting water under a pre- scribed differential head. This factor may limit the yield obtainable from wells and the recharge from percolation of sxirface waters. In stream deposited sediments, Interbedded with clays euid silts of lake de- posits, it is not uncommon for sediments to have a very low permeability in the vertical direction and a relatively high permeability in the hori- zontal direction. The low permeability in the vertical direction tends to greatly inhibit natural recharge from percolating surface waters, but the effect of this phenomenon on the yield of wells can usually be offbet by perforating the well casing in each of the water bearing strata or by gravel-packing the wells and thereby interconnecting the many lenses of water bearing strata. In general, the direction of groiind water movement in the Upper Putfiih Creek Basin approximates that of surface drainage, but in certain instemces it may have been naturally altered by the geology of the area. The direction of ground water movement is also influenced by topographic conditions, soiirces of replenishment, and areas of extractions. The major natural sources of ground water ireplenishment in the Upper Putah Creek Basin are infiltration and percolation of surface streams, and deep penetration of precipitation. In some areas, rela- tively small amounts of ground water recharge resvilt from deep penetra- tion of irrigation return flow and septic tank effluent. -99- Depletion of ground water also occurs by both natviral and man- made causes. Natural causes include effluent discharge into streams and springs, evapo-transpiration by phreatophytes, and evaporation in areas of a shallow water table. Depletion by man-made causes occur principally from groxmd water extractions by pxanping from wells or sumps and through development of spring flow. The yield of wells in the Upper Putah Creek Basin varies over wide limits depending on geologic and hydrologic factors. In general, wells penetrating fractures and joints of the older rocks of the Upper Putah Creek Basin have very low yields, incai)able of furnishing water in svtfficient q\:iantities for irrigation purposes. The highest yields are generally obtained from wells in the Recent alluvial deposits, where yields of up to l,l60 gallons per minute and specific capacities up to 59 gallons per minute per foot of drawdown have been reported. However, due to a predominance of fine-grained materials in many localities, some wells drawing from alluvi\m produce only very limited quantities of water. Principal Groxmd Water Basins The term groxmd water basin (or ground water reservoir) is used to denote areas where grovmd water is accumulated under conditions that make it suitable for develoisnent and use. A ground water basin is usually boiinded by relatively impermeable rocks, faulting, or other geo- logic stimctiire or condition that impedes grovind water movement. If no known subsurface boundary is present, a tojxDgraphic divide, or constric- tion in the water bearing material may also set the limits of a basin. .100- In some cases a ground vater basin may include areas of slight to mod- erate relief, or may include portions of fairly mountainous topography. Of the numerous small alluvial filled valley areas scattered throughout the Upper Putah Creek Basin and containing some ground water, only the four most important are discussed in detail in this bulletin. Of these Pope and Capell Veilleys contain only a few pockets of water bearing materials and generally have small yields. This condition may permit slight developnent of these valleys but the lack of ground water readily available in quantity vill be a handicap. The conditions giving rise to the situation are discxissed in greater detail later in this bulletin. The locations of the various valleys and ground water basins in the Upper Putah Creek Basin are shown on Plate 3. Collayomi-Long VsLLleys Grovind Water Basin Collayomi-Long Valleys Gro\ind Water Basin, located in the headwater area of PuteQi Creek, comprises a 8\irface area of about 8,500 acres. The two valley areas, Collayomi and Long, ar« considered as one ground vater basin because of their hydraulic and hydrologic continuity. It is the most extensively developed basin in the Upper Puteih Creek drainage. Middletown, the largest coomunity in the Upper Putah Creek watershed, lies in the central portion of the basin. Both CoHaycmi and Long Vsilleys contain extensive valley floor areas which are interconnec- ted. The boundary line of the ground water basin coincides with the edge of the valley floor areas except where water-bearing landslide debris and ■101- Quartemary basalt extend frcjm beneath the valley floor into the \ip- lands. Upland eu^as congjosed of the latter two materials, were in- cluded jji -the general outline of the basin, but d\ie to lack of data no storage estimates of these areas were made. Geology . The geologic history of the Collaycani-Long Valleys area is long and complex. IXiring the Mesozoic and early Cenozoic eras the £u:^a was p«irt of a region which was inundated repeatedly by marine seas. Great thicknesses of sediments were then deposited, lithified, deformed, faulted, and locally intrxided. IXiring the late Cenozoic era large portions of the area were blanketed by volcanic rocks. Today the Collayomi-Long Valleys area is underlain by complexly folded and fault- ed sedimentary rocks which are capped locally by volcanic rocks. Stream drainage patterns developed over a long period of time, and eventiially the ancestral courses of what are now Putah, Dry, and St. Helena Creeks were established. Since the area was being subjec- ted to strong deformation these stream courses were often modified. Upson and Kunkel (Ref . 37) have suggested that Putai Creek may have ori- ginally flowed through Long Valley smd Bucksnort Creek. This theory could explain the development of Long Valley which at present is not drained by a perennial stream. However, at some other time in the past, due to faxilting or local uplift at the eastern end of Long VeLIley, di- version of Putah Creek to its present course occurred. Two important geologic features which have a direct bearing on drainage develojxnent of the area are the Collayomi fault and the Long Valley faxilt (see Plate k) . These faults, along with a small •102- north- south fault at the southeastern end of Long Valley, bound a pie- shaped dovn-tilted block which forms the deep basin at the confluence of Long and CollaycHnl Valleys. This tilted block is about- 7 miles long and 1.5 miles wide at the southeastern end in Long Valley. It would appear that the downward movement of the favilt block was greater near Putah Creek than at the southern end of Long Valley. The Collayoml favilt is reaxLily identifiable, strikes N67*^, and dips nearly vertically. Based on drainage offset, the Collayomi fault has aji apparent surface displacement of about one mile. The fault has been traced definitely for about 12 miles from Whispering Pines through Butts Camyon, ajid may extend much further to the southeast. The Long Valley fault begins in Collayomi Valley where it appears to branch off the Collayomi faiilt. It continues southerly, striking N50'^ and dipping nearly vertically, into Pope Valley, where it may bound the northeast side. The Collayomi and Long Valley faults appear to control the composition and thickness of the alluvium in Collayomi and Long Valleys and also along Putah Creek downstream from the ground water basin. Well 111I/7W-33L2, located in Collayomi Valley at a surface elevation of 1,100 feet, intersected the alluvium-bedrock contact at a depth of kkh feet, elevation 656 feet. In the canyon of Putah Creek below the Collayomi emd Long Valleys at surface elevation 1,0^ feet, the estimated depth of alluvium is only about ^+0 feet, with the alluvium- bedrock contact being at elevation 1,000 feet. Thus, it appears that bedrock in Collayomi Valley is about 350 feet lower in elevation than bedrock in Putah Creek Canyon, downstream from the ground water basin. Bedrock -103- crops out at the southeastern end of Long VeuLley, at elevation 1,130 feet. This indicates that the bedrock surface has a rise of about kj^ feet in the k^ miles traversed from well 11N/7W-33L2 to Putah Creek Cemyon. These incongruities in bedrock elevation may most logically be explained by contemporaneous faulting and deposition (as shown on Figure 7). It would appear that the block between the Collaycmi fault and the Long Valley fault, including part of Collayomi Veilley and neajrly all of Long VaJLley, underwent a downward displacement with respect to the areas north and south of it. As this faulting occxtrred, Putah Creek continxied to flow adong its course and maintained grade by eroding the block north of the Collayomi fault and depositing its load in the downfaulted area. If, during this period of time, the \iplift along the Collayomi favilt exceeded the capacity of the stream to erode through the uplifted block, a lake was probably formed (see Figure 7 (b)). The lithology in the basin was thus controlled by the environmental conditions in the valley. Coeirse- grained stream gravels emd samds with associated finer-grained flood plain deposits accumulated during times when the valley was occu- pied by a stream, euad silt and clay predominated whenever the basin was occupied by a lake. The stream deposited material of the Recent aJJ.\iviimi is gener- ally the most important water-bearing unit of the basin. The lithologic character of the alluvi\m is directly controlled by the drainage develop- ment and structural history of the area. Assuming the hypothesis con- cerning the Collayomi faiilt to be correct, Collayomi and Long Valleys have been subjected to periods of inundation. While the valleys were flooded. -IOJ+- SOUTH NORTH (a) JK JK LONG VALLEY FAULT COLLAYOMI FAULT Profile during period of eontemporoneous fouit movement ond oeeumulotion of stream deposited alluvium in down - faulted block Note modification of fault scarp. LAKE-/ JK (bl Profile during period wtien uplift of tt\e north block exceeded deposition of olluvium in downfaulted block. Lake occupies basin. (C) Present profile ; foulting hos ceased ond stream is aggrading. LEGEND STREAM «N0 FLOOD PLAIN DEPOSITS LAKE DEPOSITS BEDROCK OF JURASSIC-CRETACEOUS AGE SYMBOLS ARROWS INDICATE DIRECTION OF LAST APPARENT FAULT MOVEMENT NOTE GEOLOGIC SECTIONS ARE DIAGRAMMATIC ALONG PUTAH CREEK, AND ARE NOT TO SCALE DIAGRAMMATIC SKETCH SHOWING HYPOTHETICAL EVOLUTION OF COLLAYOMI-LONG VALLEYS GROUND WATER BASIN 103 FIGURE 8 ^ laSigJ LEGEND STREAM DEPOSITS COAASC-ORAINED VATC RIALS, GOOD PEflUEABILITY- LAKE DEPOSITS FINE-GRAINED yATERIAL, LOW PERMEABILITY FLOOD PLAIN UEOIUM-FINE-ORAINEO MATERIAL. L0« PERMEABILITY SLOPEWASH COARSE-TO FIHE-GRAINEO MATERIAL. POORLY SORTED. GENERALLY LOW PERMEABILITY JURASSIC -CRETACEOUS BEDROCK, I.APERMEABLE. NOTE: GEOLOGIC SECTION NOT TO SCALE. DIAGRAMMATIC GEOLOGIC SECTION OF STRATIFIED MATERIALS IN THE COLLAYOMI-LONG VALLEYS GROUND WATER BASIN 106 fine-grained lacustrine materials were deposited in the valley. Once erosion cut through the barrier at the mouth of the valley, typical stream laid gravels smd sands were deposited along with the associated fine-grained flood plain materials. It appears that at any given time the coarse-grained materials occupied only a small portion of the valleys. This is illustrated in Figure 8. In general the stream deposits are gravels, sands, ejid asso- ciated silts. These sediments generally are the most permeable units in the basin and may reach a maximum depth of over UOO feet. In contrast, the fine-grained sands and silts deposited on the flood plain have low permeabilities. The lowest permeabilities of all are found in the lacustrine deposits. These appear to be the blue clays so often reported in the well drillers' logs. The deeper lacustrine deposits are believed to belong to the Cache formation. Numerous areas of landslide debris consisting of sl\imped rocks and talus, generally associated with serpentine and Franciscan rocks, surround Long Valley euid Collayomi Valley. The accumulations consist of an unconsolidated and iinstable mixture of rock and soil. The unit is locally permeable; however, its limited areal extent precludes it tram being of importance as an aquifer in the ground water basin. The Quaternary basalt crops out locally both north and east of Middletown. The log of well 11N/7W-3UJ2, indicates the presence of a ledge of hard gray rock, presumed to be basalt, from depths of 72 to 85 feet. From the log of this well, it appears that the basalt may extend across the valley as a flow interbedded with lacustrine sediments of the Cache formation. In outcrop, the basalt is fractured and broken and shoal d ■107- have good overall permeability. Thus, when situated beneath the vater table, it may be capable of yielding good quantities of water. In general, the sedimentary, landslide, and volcanic water- bearing deposits are flanked and underlain by materials of the Francis- can-Knoxville groups consisting of marine deposited graywacke, shale, and associated rocks which are locally intruded by serpentine. These rocks are generally considered to be nonwater-bearing although in some areas joints, faults, and shear zones probably contain some water. Hydrology » Ground waters throughout the Collayomi-Long Valleys basin are not stored in a single mass of homogeneous sediments with unre- stricted lateral and vertical movement, but occior in a series of confined, semiconfined, and unconfined layers, compartments, and lenses of permeable or semipermeable materials which are partially merged emd interconnected. There is no evidence of any well defined aquifer of great areal extent within the basin. The phenomenon of confinement is evidenced from several well drillers' logs which show the level where water was first encountered to be below the standing water level in the well after completion. The total volimie of saturated valley fill material is estimated to be i^00,000 and 240,000 acre-feet in Collayomi and Long Valleys, respec- tively. Analysis of well logs indicates that the valley fill materials range in specific yield from 3 percent for clays to 25 percent for grav- els. The overall average values are 6.5 and U.5 percent in Collayomi auid Long Valleys, respectively. From this it is indicated that the gross ground water storage capacity in the Collayomi -Long Valleys Basin -108- is about 37>000 acre-feet. Not all of this storage capacity is usable, however, because of practical considerations of basin opeiration. A fev periodic records of water level measurements in wells are available for the period beginning with the early 1950's. These measvirements indicate that water levels in the basin are drawn down by pxsnping dxiring summer months and that the basin fills up each year during the winter and spring months. Vfhile these measurements are in- sufficient to determine ground water flow pattern it is believed that ground water movement, in general, follows the same direction as surface drainage. Measurements of water levels in about 53 wells were made in Collayomi-Long Valleys in the fall of i960 and the spring of I96I. To accurately determine the pattern of ground water flow from these measure- ments it would be necessary to first determine the reference i»int ele- vations by field survey. This was not done due to a limitation of time and funds. However, on the basis of the water level meas\irements, the average rise in ground water levels throughout the basin for this i)eriod was estimated to be about eight feet. This rtse of water levels was estimated to represent a change in storage of fnan 3,000 to U,000 acre- feet, or about 8 to 11 i)ercent of the estimated total quantity of water stored in the basin. The major source of recharge to the Collayomi-Long Valleys Basin is from percolation of stream flow in Putah, Dry, auid St. Helena Creeks, although some recharge is derived from deep penetration of rain- fall and irrigation return flows. These streams comprise about 80 percent of •109- the 40 square mile drainage area tributary to the basin and produce an estimated mean annual runoff of about 6h,'^00 acre-feet. The estimated mean annual runoff from all sources tributary to the basin and the es- timated mean annual precipitation on the basin are 73,000 acre-feet and 31,500 acre-feet, respectively. Historically, recharge has been retard- ed by full basin conditions. Only minor quantities of surface stream flow is available for recharge in the Long Valley portion of the basin and this may be impeded to an unknown areal extent by hardpan conditions near the ground sxirface. However, it is believed that some recharge to the Long Valley portion of the basin may be derived in the form of sub- surface flow from the area of Quaternary basalt on the south and from the alluviim at the lower end of Collayomi Valley. Present Ground Water Development . Early developnent of ground water in the Collayomi-Long Valleys Basin was principally confined to dug and drilled domestic wells, althoxigh small amounts of water were pumped for irrigation. Since about 1950, a few irrigation wells have been developed; these are primarily confined to the Collayomi Valley portion of the basin. It is estimated that there have been over I50 wells drilled in the basin, of which about 100 were located during the well canvass conducted as part of this investigation. Irrigation was classified as the major use in only I6 of the wells visited. Active ir- rigation wells are reported to yield from 20 to 725 gallons per minute, with specific capacities ranging from 0.2 to 59. For the most part, active wells in Long Valley are limited to domestic and stock watering purposes. One notable exception is well nvmiber ION/TW-ICI located on •110- the Reed Ranch in the northwesterly portion of Long Valley. Althoxigh this well has not been used on a production basis, the results of pump tests indicate that it is capable of supplying over 1,000 gallons per minute . More than 50 percent of the 900 acres of land presently irri- gated throughout the basin is served wholly or in part from ground water. Although Middletown does not have a public water system, it is supplied from private dcmestic wells which often serve several dwellings. Some of the shaJLlow wells in town go dry in siamner months, and, in such cases, water is generally obtained from a deeper neighboring well. Potential for Increased Grovmd Water Development . It appears that there is some potential for increased ground water development in this basin. The total ground water storage capacity of the Collayomi- Long Valleys Basin was estimated to be about 37,000 acre-feet, and the maximum ground water storsige depletion under present conditions of development was estimated to be as much as 4,000 acre-feet. Thus, with present pumping patterns, only about 11 percent of the total available storage capacity is being utilized. It also appears that increased sal- vage of water wasting from the basin can be effected by increased extrac- tion and use of ground water with a resviltant lowertng of the water table during dry periods and increased replenishment during ensuing wet i)eri- ods. Accurate estimates of the extent of further development of ground water sujyplies from this basin could not be determined from available data. Instantaneous stream flow measurements made in November, I96O at various points on Putah, Dry, and St. Helena Creeks indicated that all ■111- •^ ':\' " V-) 16. A yoting orchard in Collayomi Valley. Water supply for this area is deiT-ved from alluvial contained groiond water. (Note well houses center and right background.) 17. Puoctii Jreek near Middletown. Percolation from stream flow to ground water occurs primarily in such stream gravels. -112- surface stream flow entering the basin, up to a total of Ik second- feet, would infiltrate into the channel gravels of these streams under natu- ral conditions. It is probable that these waters would percolate to ground water. On the assumption that infiltration and percolation are a fvinction of wetted area, and that wetted area is a function of stream flow, it was estimated, using the natural iregimen of stream flow, that the mean annual percolation from these streams could approach 9,0CK) acre-feet, provided ample storage space were made available and perco- lation was not impeded by a high water table. This amount represents only about 12 percent of the total surface sujiply entering the basin 8uid is assvnned to represent the upper limit of development from this basin unless artificial recharge methods were used. Whether or not this amount could actually be developed would depend on several factors. The principal factor is the transmissibility of basin materials. This factor controls the yield of wells etnd the lateral movement of per- colating water from the stream channels. Even though the effect of this factor could not be determined during this reconnaissance investigation, it is not unreasonable to assume that the estimated present rate of ground water extraction could be doubled if the pumping were concentrated in the most pervious materials located in the central portion of the basin near the vicinity of the confluence of Putah, Dry and St. Helena Creeks. Although increased extractions could probably be accomplished in other portions of the basin, the probability of obtaining good irrigation wells appears to be less. Under such a pleui of basin operation, distri- bution of pumped waters woiild have to be conveyed from the centralized location of the well field to other portions of the basin. •113- From a practical standpoint, however, there are legal con- siderations which must be recognized in any plan for operation of ground water storage. Under the law, an owner of land overlying a ground water basin has a paramoimt right, correlative with all other overlying land- owners, to the reasonable beneficial use of ground water in the basin. The landowner, therefore, is entitled to the protection of the law against any substantial infringement of his correlative right to ground water which he reasonably requires for beneficial use, and against any use of ground water by an appropriator which would cause impairment to his right. Increased use and changes in pumping pattern would result in a lowering of ground water levels. However, the attendant incon- venience or extra expense to an overlying landowner would not necessarily prevent such planned operation, providing it could be shown that such inconvenience or added expense were not unreasonable. The question of what constitutes unreasonable inconvenience or expense is not subject to exact determination. However, it might be assumed that greater energy costs resulting from increased pumping lifts would not be considered unreasonable as long as presently installed pumping equipment of the overlying landowner could continue to be utilized. A material lowering of ground water levels that would necessitate deep- ening of wells and/or replacement of pxmrping equipment might be considered unreasonable. In practice, these matters would have to be determined by negotiated agreement or by the courts. The success of planned operations of the Collayomi-Long Valleys ground water basin by a centralized well field would be contingent upon the negotiation of a -114. mutually satisfactory agreement between the overlying groiond water users and the operating agency of the centralized well field. Coyote Valley Ground Water Basin The Coyote Valley ground water basin is located on Putah Creek downstream from Collayoml Valley (see Plate 3). It is the northernmost ground water basin in the Upper Putah Creek Basin and has a surface area of about 10,000 acres, of which about 6,000 acres are underlain by ba- salt of the Clear Lake volcanics and sediments of the Cache formation. The boundary line of the ground water basin coincides with the edge of the valley floor except along the northeastern side where volcainlc rocks and continental sedimentary rocks extend from beneath the valley floor into the uplands. The upland area, forming the northeastern part of Coyote Valley basin, was included within the basin but was not considered in ground water storage computations. Geology . The geologic history of Coyote Valley is similar to that of the Collayomi-Long Valley Basin. During the Mesozoic auad early Cenozoic eras the valley was part of an area which was inimdated repeat- edly by marine seas. Great thickness of sediments were deposited, lithi- fied, deformed, faulted, and locally intruded. By late Cenozoic time the area was eroded into a fairly deep stream-cut valley. The ancestral course of Putah Creek pixsbably flowed throtjgh the valley following a course somewhat parallel to its present course. Then, in late Cenozoic time, the lower portion of the valley was inundated by a fresh-water lake and continental sediments now be- longing to the Cache formation were deposited. This was followed by ■115- •-»»r'= 18. Alluvium in Long Valley contains a zone of claypan at shallow depth. This condition inhibits ground water recharge, limits soil depth, and restricts agricultviral development to shallow rooted crops. It may cause ponding of surface water and extensive drainage problems under full irrigation developnent . 19. A well in Coyote Valley. This well is 110 feet; in deptn and, when drilled in 1951, had a reported yield of 1,000 gallons /minute with a 17-foot drawdown. .116- volcanism from eruptive centers immediately northeast of Coyote Valley. Outpourings of basaltic lava flowed fixan these volcanic vents euad form- ed a northwest trending ridge across the downstream end of the ancestral Coyote Valley. Subsequent faulting along the Childers Peak fault has resulted in the uplift -of the valley with respect to the ridge to the northeast. As a result of these events, the course of Putah Creek through Coyote Vaaiey, and the configuration of Coyote Valley itself, have been greatly modified with time. Knowledge of the thickness of alluvial material in Coyote Valley is meager. Well log and pump test data are scarce. None of the wells with available logs have penetrated completely through the valley fill. Based on surficial geologic observations and the four well logs available, it appears that the fill in Coyote Valley may be up to 3OO feet in thickness. Apparently, much of the basin is filled by the continental sediments of the Cache formation. Judging frcan the isolated patches of basalt which occur in the valley, it is possible that the basalt may underlie extensive portions of the basin, at least locally. Recent alluvivmi appears to occur as a veneer over the Cache formation and fill deep, buried channels. The Recent alluvium, as is the case in the other basins, is the most important water-bearing vaait of the basin. The alluvium appears to consist of poorly stratified sand, gravel, and fines. Sandy and silty gravels appear to be the best water-beairing materials in the alluvium. The gravels occur in sheets euid stringers between beds of silty clay and sandy clay. The gravels probably represent stream channel deposits •117- while the finer sediments were probably deposited on ajicient flood plains of Put ah Creek. The Cache formation crops out along the northeastern edge of Coyote Valley, locally in the valley, and probably \anderlies much of the valley. The formation is composed of gravel, silt, and tviffaceous sand with some pebbly limestone and diatomite being reported locally. The dominant constituent of the Cache beds is a light gray silt. Beds of coarse unsorted pebbles and cobbles occur locally, but these general- ly have a silty matrix. Generally, the amoirnt of fines present in the Cache beds render the unit relatively impermeable. However, occasional beds of gravel or sandy gravel having high permeabilities may occur. These beds, by the nature of their occurrence, are considered to contain confined water. Well No. 11N/6W-20D5^ near Gallagher Creek, may be pro- ducing from one or several of these confined beds. It was reported by the driller that the well is l40 feet deep ajid is perforated from 100 to ito feet. The depth to static water level varies from about 6 to 15 feet. Thus, it appears that water in this well is under about 80 or 90 feet of head. Quaternary basalt overlies the Cache beds in and northeast of the valley. The basalt occurs as a series of lava flows which are frac- tured locally. When situated below the water table, the basalt may yield scMiie water. However, it is particularly notable for accepting recharge for the groiind water basin. The alluvium, basalt, and Cache sediments are flanked and underlain by sediments of the Franciscan-Knoxville groups, serpentine. ■118- undiffei^ntiated Cretaceous rocks, emd possibly by the Martinez forma- tion. These rocks are mostly nonwater-bearing although locally, joints, faults, and shear zones probably contain some water. Hydrology . Ground water in the Coyote Valley Basin is found in the Cache formation ajid in the Recent alluvial deposits which were laid down along the old stream channels of Putah Creek. Due to the type of deposition in both the Cache formation and the alluviiun, ground water is not stored in one layer of hcraogeneous sediments but occxats in a series of sand and gravel lenses separated by silt and clay. There is no evidence of smy well defined aquifer of any great areal extent in the basin. IXie to the lack of well logs in the area, no accurate estimate of the storage capacity could be made. In 1952, the U. S. Geological Survey estimated in Water Supply Paper 1297 (Ref . 3?) that the storage capacity of the depth interval from 10 to 100 feet of the alluvium be- neath the valley floor is at least 27,000 acre-feet. This was based on an assxmed specific yield of 10 percent. Wells drilled in the basin since that time tend to substantiate this assimiption of a relatively high specific yield. Since the depth of the alluvial deposits in Coyote Valley has not been ascertained, it is impossible to estimate the total storage capacity of the basin. A few periodic water level measurements in wells have been made in the last few years. These measurements indicate that water levels are drawn down by pumping during the summer months and then recover each year during the winter months. These measurements are not sufficient -119- in number to determine groxmd water flow pattern, but it is believed that when the basin is full the movement follows the same general direc- tion as the surface drainage. Localized dewatering by pimrping may cause the movement to deviate from the general direction of surface drainage to such aji extent that the wells in the vicinity of Crazy Creek and Gamble Road may be drawing some of their ground water from the vicinity of Putah Creek. Measxu-ements of water levels in 20 wells in Coyote Valley were made in the fall of I96O and the spring of I96I. The average rise in water levels for this period was estimated to be about six feet. This rise of water levels was estimated to represent a change in storage of about U,000 acre-feet. The major source of recharge to the area appears to be from percolation of stream flow in Putah Creek, with lesser amounts i)ercola- ting from Coyote and Crazy Creeks. The estimated mean smnual inflow to Coyote Valley from Putah Creek is 124,000 acre-feet. An additional 10,000 acre-feet is received from all sources tributary to the basin. The mean annxial precipitation on the valley floor and the upland volcan- ic portions of the basin is estimated to be 35,000 acre-feet. The com- bined mean annual inflow and precipitation is 169,000 acre-feet. Present Groxmd Water Development. Early development of ground water in Coyote Valley Basin was principally confined to dug and drilled domestic wells to serve the few farm houses scattered throughout the valley. In recent years from 7 to 8 irrigation wells have been drilled. The yields on these wells range from about 100 to 1000 gallons per •120- minute, vith specific capacities from 5 to 195 gallons per minute per foot of drawdovm. In addition to these irrigation veils some farmers pump from sumps along Putah Creek. This latter source of supply is dependent upon the continual recharge into the basin by Putah Creek. If the recharge Is prevented by excessive pumping upstream the water table in the lower end of the valley drops below the bottom of the sumps and they dry up. The water from the sumps and Irrigation wells is used to irrigate an estimated 400 acres of agricultural lajid In Coyote Valley. Potential for Increased Groiind Water Development . It appears that there is a good potential for Increased ground water developnent in this basin. The storage capacity of the allvrvlum between the depths of 10 and 100 feet has been estimated to be approximately 27,000 acre- feet, while the maximum ground water storage depletion under present conditions of development was estimated to be U,000 acre-feet, or about 15 percent of the computed storage capacity In the 10 to 100 foot zone. The total thickness of the alluvium has not been explored. Well 11N/6W-20D5, located near the edge of the valley at Gallagher Creek, apparently penetrates a confined aquifer in the Cache formation. It is possible that the Cache formation may extend under the recent alluvixmi in the veaiey. Although much of the Cache formation is relatively taipermeable, similar water producing confined aquifers may occur at depth in other peurts of the valley. The area along the northeast side of the basin, bordering the outcrop of the Cache formation, is relatively tight. With the exception of well 11N/6W-20D5 there have been no high producing irrigation wells ■121- drilled in this area. The best area of potential well development ap- pears to be limited to that portion of Coyote Valley which extends along the south side of Putah Creek from the Highway 53 Bridge south- westerly to Crazy Creek. Instsmtaneous stream flow measvirements made in November i960, at various points on Putah and Coyote Creeks, indicated that all sur- face stream flow entering the basin up to a total of 9 second-feet would infiltrate into the channel gravels of these streams \ander natiiral con- ditions. On the assumption that infiltration and percolation axe a function of wetted area, and that wetted area is a function of stream flow, it was estimated, using the natural regimen of stream flow, that the mean annual percolation frcsn these streams could approach 9^300 acre-feet, provided ample storage space were made available and perco- lation was not impeded by a high water table. This amount represents only about 7 percent of the total inflow to the valley and is assumed to be the upper limit of development frcan the basin unless artificial recharge methods were used. It is impossible to determine at the present time the amount of potential development available. This amo\ait depends primarily upon transmissibility of the alluvium and the Cache materials. This factor not only controls the yield of wells but also the lateral movement of percolating water frcan the recharge areas. Even though the effect of this factor could not be determined, it is not unreasonable to assume that the estinated present rate of ground water extraction could be tripled if the pumping were concentrated in the central portion of the -122- basin. Increased extractions could probably be accomplished in other portions of the basin, but the probability of obtaining a good irri- gation well in the fringe areas is much less. The development of a centralized well field woxild require the distribution of its pumped water to other portions of the basin near its periphery. The legal considerations involved in such an operation have already been dis- cussed in the preceding section on Collayoml-Long Valley Basin. Pope Valley Pope Valley is located about six miles west of the northerly portion of lAke Berryessa (see Plate 3). The valley is drained by Pope Creek, emd its principal tributary, Maxwell Creek. Grovind water occvirs in the all\ivl\im and in several areas of pervious volcanic rocks near Aetna Springs. The areal extent of the water-bearing rocks in Pope Valley is about 9>300 acres. The boundary between the water-bearing and nonwater-bearing materials roughly coincides with the edge of the valley floor, except for a few acres of upland volcanic rocks near Aetna Springs. Geology . The bedrock which underlies Pope Valley represents the same sequence of Mesozoic marine sedimentary and volcanic rocks which occur elsewhere in the Upper Putah Creek Basin. Tope Valley lies in an area which was inundated repeatedly by marine seas during Jurassic euid Cretaceous time. Tremendous thickness of sediments were deposited, lithlfied, faulted, deformed, auid locally intruded by serpentine and associated rocks. During the Oanozbic era, the area was uplifted and eroded and Pope Valley develoi)ed into a rather bro€ui area of vindulating -123. land surrovmded by higher ridges. Apparently, throughout the history of the valley, stream development has been limited to small creeks. Thus, Pope Valley has developed primarily as a structural basin rather an erosional basin. The fact that Pope Valley was structurally formed is impor- tsmt in that great thicknesses of alluvivm generally associated with large streams did not accumulate. In fact, based on the few, scattered well logs available, it appears that the alluvl\an may average only about 25 to 30 feet in thickness. Since large stream flows are lacking, the alluvium consists chiefly of silty and clayey sands and gravels. Geologic inference indicates that clean sand and gravel lenses may oc- cur, although none have been observed. Although the alluvivmi is tight it yields limited quantities of water. Several small outcrops of Sonoma volcanic rocks occur near Aetna Springs. These rocks, generally considered as water-bearing, ai^ of such a local nature ajid so isolated that whatever extractable ground water they contain is not of significant quantity. The remainder of the basin is \anderlain by marine sandstones and shales of Jurassic-Cretaceous age, and by Jurassic serpentine. Con- nate water could be encoxmtered locally in the marine sediments. Several deep we3J.s have penetrated these rocks, but with only one exception, they have not encountered significaxit qxoantities of water. These rocks are considered as nonwater-bearing although sane water may be found along fault ajid shear zones. -121^- Hydrology « Ground water in Pope Valley is found in limited quantities in the shallow alluvium and along fault and shear zones in the underlying marine sandstones and shales. Due to lack of veil logs in the area, no accurate estimate of the storage capacity could be made. A rough estimate can be made by assvniing an average thickness of alluvium of 25 feet and an average specific yield of 3 percent. Using these assumptions the storage capacity of the alluvium would be about 7,000 acre-feet. Most of the SLLLuvigil material is relatively thin, patchy, and impermeable, making it uneconcmical to utilize this storage capacity through pumping. A few periodic water level measurements in wells were made in 195^-55 and 1960-61. These measuremehts show that water levels are drawn down by pumping and natural causes during s\mmier months and recover each year during the winter and spring months. The average recovery in 26 wells frcan fall I96O to spring I96I was about 9 feet. These measure- ments are not sufficient to determine ground water flow pattern, but it is believed that when ground water levels are high movement is toward the creeks. It is believed that the major source of recharge to the area is from infiltration of winter precipitation, with the exception of small isolated areas adjacent to surface gravel deposits along portions of Pope and Maxwell Creeks. A series of instantaneous stream flow meas- urements were made at various points along Pope, Burton, Hardin and Maxwell Creeks following the first storm of the season in November I96O. This series of measurements indicated that very little water (about 3*5 cfs) was percolating into the alluvium from the stream flow. Following .125- the second storm of the season, the alluviiaa was yielding water to the streams. Present Grovind Water Development . Early develojaient of groimd water in Pope Valley was limited principally to dug and drilled domestic wells to serve the few farms and ranches scattered throughout the Valley. In recent years, several attempts have been made to develop irrigation wells. Wells more than 900 feet deep have been drilled with little success. At the present time, there is only one well in the valley, well 9N/5W-IIJI, which has a reported yield of more than 100 gallons per minute. Potential for Increased Ground Water Development . There seems to be little chance of developing wells of sufficient yield for irriga- tion in Pope Valley due to the limited thickness of the alluvial mate- rial and its relatively low permeability and specific yield. Futvire development in the valley will probably be limited to low yielding dcsnes- tic wells. Capell Valley Capell Valley is the southernmost area in the Upper Putah Creek Basin that was investigated for ground water develojsnent . The valley is a narrow northwesterly trending depression which varies from about 500 feet to 3,300 feet in width along the valley floor. It is about k.3 miles long with a svirface area of app3X>ximately 9OO acres. Capell Creek and its principal tributary. Oak Moss Creek, flow northwesterly through the valley, emptying into LaJce Berryessa about 2 miles downstream. -126- lUBi I Geology . Capell Valley appears to be a structural depression I underlain by marine shale, sandstone, and related rocks of the Knoxville I group of Jurassic age. The hills suid ridges surrounding the valley are composed of rocks of the Knoxville group. These rocks contain occasion- al masses of Jurassic basalt Intruded by serpentine. The ridge to the west of Capell Valley, which forms the drainage divide between the Napa River emd Futah Creek, is capped by the Sonoma volcanics of Pliocene age. Recent alluvium veneers the V£jJ.ey floor to a shallow depth amd landslide debris occurs locally on the svirrounding hill slopes. The evolution of Capell Valley has been quite coaaplex. Tbe presence of several large favilts, which roughly bound the valley and strike parallel to it, suggest that down-faulting may have occvirred. Thus, like Pope Valley, it appears that Cape]-1 Valley was formed by structural rather than erosional activities. Apparently, stream developnent in Capell Valley has been of a local nature and did not result in deposition of large qioantities of good water-bearing sands and gravels. The alluvium consists primarily of silt and fine-grained sand derived primarily frcm the weathering and erosion of the surrounding hillsides of sandstones and shales of the Knoxville group. Due to the fine-grained natiire of the thin alluvium, only very limited quantities of water may be expected from wells drilled through it. In fact, based on records of the few wells located in the area, the ground water available is barely sufficient for present domestic needs. On the west side of Capell Valley several wells have been drilled into rocks of the Knoxville group. These wells produce some -127- potable water which appears to be coming from fractures in the bedrock. Maximim reported production in this area is about 10 or 12 gallons per minute, with a drawdown of about 100 feet. Generally, these rocks are considered to be nonwater-bearing. Hydrology . Ground water in Capell Valley occurs in very limited qxiantities in the Recent alluvium and locally in fortuitously fractured Khoxville bedrock. Due to the mode of deposition and the conaposition of the alluvivmi, ground water is not stored in large extensive beds but in local sand and gravel lenses. There is no evidence of any extensive, well-defined aquifer in the basin. Due to lack of well logs in the area, an accurate estimate of the storage capacity was not atten5)ted. However, assuming an avereige thickness of alluvium of 25 feet and an average specific yield of 3 percent, the storage capacity of the alluvium would be approximately 700 acre -feet. Dewatering of this small amoxmt of storage through pumping appears to be impractical and uneconomical. Water level measvirements in a few existing wells were made in fall i960 and spring I96I. These measurements indicate that the water levels are depressed by natural causes and pumping in the svmmter and fall months, and recover in the winter euid spring. The average recovery in 9 wells from fall i960 to spring I96I was about 15 feet. These meas- urements are insufficient in number to determine flow patterns, but it is likely that the movement is toward Capell and Oak Moss Creeks. It is believed that the major source of recharge of the alluvium is from infiltration of winter and spring precipitation. -128- Present Ground Water Development . Elarly development of ground water in Capell Valley was limited principaJ-ly to dug and dril- led domestic wells to serve the few farms and ranches scattered through- out the valley. At the present time, there are no wells in the basin with a reported yield in excess of 15 gallons per minute. Potential for Increased Ground Water Development . It appears that there is little chance of developing wells of sufficient yield for irrigation in Capell Valley. Future ground water development in the valley will probably be limited to low-yielding domestic wells. ■ 129- Summary ajid Evaluation of Grovmd Water Conditions Information on grovmd water vlthln the Upper Putah Creek Ba- sin is limited. The data collected for this reconnaissance Investiga- tion indicate that the prospects for developing additional ground water supplies throughout the major portion of the watershed are not favorable. Principal exceptions occur in Collayoml and Coyote Valleys where a sub- stantial portion of present agricTiltural water reqxiirements are met from existing wells. In general, the vairtous geologic \inits comprising the basin may be grouped into four broad categories relative to their water-bearing properties as follows: (l) the marine and intrusive rocks of Mesozoic and early Tertiary age, (2) the Tertiary continental rocks, (3) the Ter- tiary and Quaternary volcsmic rocks, and (h) the Recent alluvixm. The marine and intrusive rocks comprise about 76 percent of the surface area of the basin, and contain relatively little extractable potable water. Locally, where Jointed or faulted, they are capable of yielding small qiiantities of grovmd water sufficient for domestic and stock-watering purposes. The Tertiary continental rocks, comyposed of the Cache forma- tion and its correlatives, comprise about one percent of the surface area of the basin. They have relatively low permeabilities but are less con- solidated emd more permeable than the older rocks. Local lenses of clean sand and gravel may occur and be capable of yielding small to moderate quantities of water to domestic wells and springs. A well in Coyote Valley with a yield in excess of TOO gallons per minute and a specific •130- capacity of about 9 gallons per minute per foot of drawdown, is believed to penetrate a segment of the Cache formation underlying the alluvium. Whether or not the well truly penetrates the Cache formation or if all the water is derived therefrom could not be definitely ascertained. The Tertiary and Quaternary volcanic rocks comprise about 13 percent of the surface area of the basin. The Tertiary volcanics are generally of low permeability except locally where sandy tuff is capable of yielding fair quantities of water to wells. The Quaternary volcanics generally are capable of yielding only fair amounts of water, except in areas where highly fractured basalt occurs in the zone of saturation. In the latter case good qxiantities of water can be expected. The Recent alluviimi, by far the best known water producer in the basin, comprises the remaining 10 percent of the area of the basin. Production from the alluvium is quite variable and depends upon the method of deposition, composition and thickness of the sediments. Of the major valley areas studied only certain portions of Collayomi, Long, and Coyote Valleys have good possibilities for additional groimd water development. Opportunity for further development in Pope and Capell Valleys is not favorable. The water-bearing characteristics of the nu- merous small and somewhat isolated alluvial areas, such as occur in Si)anish, Snell, Paradise, and other valleys, were not studied as part of this reconnaissance investigation and no known data ar^ available for these areas. -131- CBAPTER V. POSSIBLE SURFACE STORAGE PROJECTS The quantity of water originating in the Upper Putah Creek Basin greatly exceeds all possible future beneficial uses which may rea- sonably be anticipated in the basin. Nevertheless, because of the inter- mittent character of runoff in most streams, the basin experiences natural deficiencies in water supply during the summer and fall months. Moreover, this seasonal deficiency is intensified by prolonged periods of drought. Under present conditions, direct diversions from unregulated stream flow must be curtailed dvirlng periods of low runoff. Gro\ind water is used to lessen the deficiency in siirface water supply in some locali- ties, and surface storage is used in other areas. If the erratic runoff is to be harnessed to the needs of man sxifficient storage will have to be provided to temporarily store the excess runoff of very wet periods. The question as to whether the storage capacity and regulation shoiild be provided by svirface reservoirs or ground water basins will depend upon the physical potential of ground water, and the cost of the method selected. Previoxis studies have been, for the most paxt, limited to proj- ects which could have been constructed as alternatives to Monticello Res- ervoir (Lake Berryessa), and projects that could be used in transporting water from the North CoastsJ. Area to the major water deficient areas of California. During this investigation, an inventory was made of possible dam and reservoir sites for locsuL use. Sites studied during previous in- vestigations were reviewed and evalxiated with respect to their possibili- ties for serving local areas. Several new sites which appesired to be -133- susceptible to local development were examined. Results of these studies are presented in this chapter. Effect of Upstream Development on Yield of Monticello Reservoir Additional upstream vater development will deplete the vater s\ipply available at Monticello Reservoir. This depletion vlll, in turn, reduce the safe yield obtainable from Monticello Reservoir. The net re- duction in Monticello yield cainnot be determined directly from the amoiint of additional upstream storage capacity constructed nor yield derived therefrom. A combination of factors such as reservoir storage capacity, reservoir yield, reservoir evaporation, irrigation return flow, irrecov- erable losses of return flow, euid increased yield obtainable from the basin must be considered in making this determination. To determine the reduction it wovild be necessary to ascertain conditions as they would exist xander a specific proposal or combination of proposals for upstream development. Since this is not possible at this time, the following hy- pothetical situation will demonstrate the order of magnitude and the interrelationship between these factors. AssvQie that a reservoir or group of reservoirs with an aggregate storage capacity of 60,000 acre-feet are constructed in the upper basin. This amount of storage capacity covild provide a safe smnual yield on the order of ^^5,000 ^cre-feet, with an average annual net reservoir evai>ora- tion of about ^4^,000 acre-feet. Since irrigated agriculture is the principal present auid poten- tial use of water, assxmie that the entire annual yield would be used for that pvirpose. Although in this i3JLustration the use of the total upstream .13i^- supply developed is based on irrtgatlon use, similar conditions would exist in the case of urbsui axid suburbeui uses of water. All water applied to the land is not consiimptlvely used in most irrigation practices. The ratio between consumptive use of applied water and the total amovmt of irrigation water applied varies widely between crops and among plots devoted to the same crop, depending on such factors as soil, topography, method of irrigation, drainage charactertstics, and practices of the individ\ial irrigators. For this example, assume that this ratio, called irrigation efficiency, is 70 percent. Average annual flow, that portion of the totai applied water which is not consumptively used, would be 30 percent of ^,000 acre-feet or 12,000 acre-feet i>er year. All of this return flow would not reach Monticello Reservoir; some of it would be lost to native vegetation en route. The magnitude of this loss would be dependent on the type and extent of vegetation between the point of use ajid Monticello Reservoir, and the distance fixsm the lake. For this example, it appears reasonable to assvmie I/3, or 4,000 acre-feet per year of the retvim flow would be lost. Additional storeige capacity in the basin will increase the total amount of water conserved from the basin. This is illustrated by Figure 9 • The figure depicts the approximate relationship between storage capacity and yield of the basin. It shows the present level of development euid illustrates that additional storage capacity would provide a small incre- ment of additional yield from the potentially conservable waste that exists under present development. Because of the extremely long carry-over period required, the 60,000 acre-feet of additional, storage capacity woxild increase basin yield by only about 3,000 acre-feet per year. -135- FIGURE ADDITIONAL SI CAPACITY REQU CONSERVE PRESE 0RA6E HJ WASTE ?i a K t- > z 1 1 ^.-^^f""^ NET INCREASED £° <^- -1^- S BASIN YIELD i I 1 ( ASSUMED STORAGE CAPACITY /^ developm NT WORKS / o a > >- a. a lu ■1 Q (L O z O -1 -1 z i > z IT a. I o 0. I Z z Z s o tf '^ ^ ^ y r- ^ < ^ ' > A ^ > >- -> ' "^ T ^ A V ' '-l.>^^-' 77v A < -7 -J ^ ^ 7 RELEASES FOR STREAM PRIOR DOWN- RIGHTS 1. -»"'»*-''*•.''** * -.',•,**. vi-.'O'^x^vr-v^^t .<%''><>'/*r'':;-'"'." PRESENT UPSTf EAM NET USE BASIN STOHAGE CAPACITY, IN MILLIONS OF ACRE-FEET EFFECT OF ADDITIONAL UPSTREAM DEVELOPMENT ON YIELD OF UPPER PUTAH CREEK BASIN 136 ■ r \\ I Based on these assumptions, the net effect of the upstream de- velopment, as shown in Table 20, would be to reduce the annvial yield of Monticello Reservoir by 33,000 acre-feet. It is significant to note that the net reduction of yield at Monticello Reservoir could be significantly less than either the vrpstream storage capacity or the reservoir yield. TABLE 20 ILLUSTRATION OF EFFECT OF HYPOTHETICAL UPSTREAI-I WATER EEVELOPMENT ON YIELD OF MONTICELLO RESERVOIR In acre -feet per year Item : Items tending to decrease yield at Monticello Reservoir : Net reduction of litems tending: yield from to increase :Monticello Reservoir yield at :due to hypothetical Monticello : upstream water Reservoir : development Safe yield of hypothetical upstream water development works itO,000^ ' Net increase in basin yield from PutEih Creek Basin development works 3^000 Net reservoir evaporation '+,000^ Return flow of irrigation water 12,000*^ Irrecoverable loss of return flow ^.000^ Totals W,000 15,000 33,000 a Based on a total of about 60,000 acre-feet of storage capacitv. b Based on basin-vn.de storage development curve (see figure V-1) . c Based on TO percent irrigation efficiency. d Estimated as l/3 of irrigation return flow. -137- Inventory of Possible Dam and Reservoir Sites Investigation of possible sxirface storage developnents in the I^yper Putah Creek Basin included studies to determine amounts of water that could be developed by constructing reservoirs of various sizes at nxmerous sites. Surface geologic examination was made to determine suit- ability of each dam site for a particular type of dam and its limiting height. Reconnaissance estimates of capital and average ftnnna.1 costs were made for the purpose of establishing economic relationships between the various sizes of reservoirs. Preliminary examination was made of 31 possible dam and reser- voir sites, of which 12 were considered to be the more favorable ones. In addition, three stream flow diversion sites were studied to augment the yield of nearby potential storage reservoirs. Nineteen dam sites were eliminated on the basis of poor geologic or topographic conditions, limited water supply, high capital costs, excessive unit costs of water, and/or poor location. These are listed in the following tabulation. Their locations are shown on Plate ^, "Locations of Items and Reservoir Sites". Dam 8uid Reservoir Sites Eliminated Lsike County Dam and Reservoir Stream Upper Dry Creek Lower Dry Creek Harbin Upper Middletown Lower Ci^zy Creek Guenoc Stelnhart Jerusalem Bucksnort Noyes Dry Creek Dry Creek Harbin Creek Putah Creek Crazy Creek Putah Creek Soda Creek Soda Creek Bucksnort Creek Putah Creek Napa County Item and Reservoir Stream Devils Head Snell Snell Valley 7.^n1 Zlm Upper Hardin Lower Hardin Lower Goodings Upper Capell Lower Capell Putah Creek Putah Creek Butts Creek Etlcuera Creek Hardin Creek Hardin Creek Maxwell Creek Capell Creek Capell Creek -138- For each of the sites chosen, reconnaissance estimates were made of the mean annual precipitation on the drainage area above the dam site, the mean annual runoff available at the dam site, the peak flow for the spillway design flood, the mean annual vmit evaporation and local geologic conditions. Estimates of mean annual precipitation were based on records at the precipitation stations and a vailable isohyetal maps previously described in Chapter III. Estimates of mean annvial runoff at the sites were derived from correlations of mean annual precipitation and mean annual runoff based on records of measured streams within suid near Putah Creek Basin. These runoff values were reduced by estimates of pres- ent upstream impairments. Estimates of the peak flow for the spillway design flood were based on reconnaissamce estimates of the T2-hour prob- able maximum precipitation, assimed loss rates, based on similar studies in adjacent aa-eas, and unit hydrographs developed for gaged areas in and adjacent to the basin. Estimates of mean annixal \jnit evaporation were based on records from some 30 evaporation measiirement stations located within the Central Valley and tributary areas. Values of net evaporation rates were computed as the difference between gross evaporation and the consumptive use of precipitation by native vegetation in the reservoir area. The results of these estimates of hydrologic factors at the chosen sites are presented in Table 21. The relationships between storage capacity and reservoir yield were determined on the basis of regional storage-development curves for the gaged areas of the basin. In constructing these curves, the monthly distrtbution of annual yield was based on an irrigation demand schedule as presented in Table 22. -139- ■d (U •H W w 3 c .. H U 4J O •^ 0) P. C (I) Cd O Cm ClJ 0) > -H C (U -P ■P •H •P (0 W o to r-( P< c a > bO •> C -P H -H T) O (U ,H W O O (U •H 0) O 0) ^ PL( T3 iH in CO -cotx>cocococo cvjcvjajojCMCvicvjoj oo o o oo o o oo o o O^CO OJ --t ^ o o o o o o o o o LP>(M t— 80 o o o o o o o o o o o J- UfNVO 0O"~^O t-~ ON CVJJ- C\J CM HMD oo OJ rH O CM H rH H irvJ- MD LTN OJ CX) O ON r--vo ir\ LP>-d- mcfN-d- t^oc^j- m i/Nvovo • • • • "^^^.^^ • • • CX3f-r— LTN UlLTNCOO VOOO <-! H F-F-F-F-F-MDVDVOVO s s s O O rH ^ a 3 ^?sa rH rH H ■"^ H H H H rH CJnVO m,^ ITNCO O CTnJ- OJ H H OJ rH rH OO •ij >8 J- J>5 Jri ^fH 0) rH U C3 o G O M 0) 0) td G "^-S-S >5-p ^3 O o to >= • -p +i cd >> tiDV Q CO (5h & O m m a o >» ^ ^ cd irf^-p >> d jsj ^i a) --■ 0) u 0) G 0) 0) (U GU cd ^, OJ Q) ^ O .Tl u Q) W -P u C) G > -P u u s. GT) N o crt t? •HT) -p td >, tiOH «» ^■^ (2 u o •H G Q o o WW C3N ON O O O C3\0 • •••••• OJ OJ on oo oo OJ OO O O O O O O O O O O O O O o O O O O O O o •V "V "V •v •\ •% "X r»- ITN iri_* VO LP> OJ CM H CM o o o o o o o o o o o o o o t— O I---X) OOVO OJ •X •%•*•* "x •* •v t^CO OO^ M3 J- t^ rH oo rH H H OO CM CX) H OJ LTN LTN LTN OO m ro ro CM a\ o\ C7\ J- oo oo o • • • • • • • O LfWO CO ooco J" H ^ oo CTN ts s ts > 5 s 5 M3 VD LTN LTN-d- OO-d- S S S S g i O ON ON ON CT\ I O VO rH ITN CM CK O CM oo rH OO rH rH CM CM M .VJ ^ i) j^ H => C) > Q) CJ t S ft o ^ ft Cd •H -P >-i CO a, :^ o W :^ ^V, 9> to tiO G (U (1) ? ^ d) X ft u CJ td CO u ■^ >H N to -P ^ 0) tu J-. 0) -P td ft r-{ •-3 <§ S:^ a> u CO o w G H tl) ft c o •H ■P ft ■H o w V t3 0) -P •H O td ? O -d G 43 -H >!g & u "d td J tu -p -p G tu s 3 x( cd vH (u a c3 x: ■p tu •H to G tu O -P -H •H -P CO td o a o G _ -H bO td cd -3 o H ■H G O •H ■P O G O o cd -H 0) tu x: ;h -p tu X! ^ S O rH -H lU o « « w ^ ^ ol -ll^l- TABLE 22 ESTIMATED AVERAGE MONTHLY DISTRIBUTION OF ANNUAL AGRICULTURAL DEMAND FOR WATER Estimated average irrigation demand for water, in percent of annual total Month Estimated average irrigation demand for vater, in per- cent of annual total October November December January February March 5 April May June July August September TOTAL 5 9 17 26 21 IT 100 Safe yield, the max1nn.m sustained annual draft that could have been maintained throughout a critically deficient period of water supply during the period of record, reflects abnormal 1 y dry conditions, and is belov the yield that could be obtained in most years. Studies to deter- mine the water supply deficiency that might be endured without permanent injury to perennial crops have not been made for the Upper Putah Creek Basin but have been made for other areas of California. The results of these studies indicate that a maximum annual deficiency of 35 percent of the full seasonal water requirement can be endured if the deficiency occurs only at relatively long intervals. It has also been established that small deficiencies occurring at relatively frequent intervals can be endured. Therefore, because the safe annual yield reflects abnormally dry conditions, and because a greater and more realistic use of water for irrigation pur- poses could be made by allowing ein occasional deficiency, estimates of firm somual reservoir yield contained herein have been adjusted to allow for a maximum annual deficiency of 35 percent, but were limited by an aver- age annual deficiency not in excess of 2 percent per year during the entire -U2- 50-year mean period. For those reservoirs which would primarily be used for domestic purposes, estimates of ajinual yield have been computed on a safe yield basis with no deficiency. Reconnaissance cost estimates were made for the remaining 12 dams and reservoir sites investigated. Estimates of cost and reservoir yield were made for several sizes of reservoirs at most of the sites. Detailed spillway designs wei-e not made, but freeboard between normal pool elevation smd dam crest elevation was provided in s\ifficient amount to allow for passage of the maximum probable flood over a reasonably sized spillway. These preliminary studies resulted in approximate fig- ures, which were sufficiently accurate for comparative purposes. Some of the comparisons made between alternative dam sites were size versus cost per acre-foot of water, and capital cost per acre-foot of storage capacity. Constiniction costs of dams and appurtenant structures were based on total volume of earth embankment and average recent bid costs (from 1958 to i960) of dam and appurtenajices per cubic yard of embank- ment. These bid costs are shown in Table 23. A value of $2.00 per cubic yard of earth embankment was used in estimates of construction. In addition to the costs of construction, estimates of capi- tal costs included allowances for acquisition of land aind improvements, relocation of roads, reservoir clearing, contingencies, administration, engineering, and interest during the construction period. Estimates of annual costs, included interest on the capital investment at four per- cent per annum, amortization over a 50-year repayment, and allowances for replacement, office and overhead expenses, and operation and main- tenance costs. -li^3- TABLE 23 SUMMARY OF COST DATA FOR SIX RECENTLY COMPLETED DAI'lS MD ESTIMATE OF AVERAGE UNIT CAPITAL COST 1 Neune of dam and Height of dam, in feet : Length of :dam crest; : in feet • • : Total volume: :of earth em-: : bankment , in : : cubic yards : Bid cost of dam and 1 appurtenances, in dollars per cubic yard reservoir Successful: low bidder: Average of: all bids : High bidder Terminus 250 2,375 7,128,000 1.33 1.60 1.76 Prosser Creek I50 1,840 1,739,000 1.25 1.70 2.11 Union Valley iwDO 1,880 10,118,000 1.3^ 1.89 2.1+2+ Whale Rock. 210 850 2,500,000 1.27 1.56 2.16 Trinity 505 2,1+50 29,000,000 1.70 1.81 1.91 Miramar lh8 1,190 830,000 1.63 1.86 2.38 Average unit cost of construction 1.1+2 l.7h 2.13 Engineering and administration, 105& .11+ .17 .21 Subtotals 1.56 1.91 2. 31+ Interest during construction, k'jL for construction period^ 1/2 of .06 .08 .09 AVERAGE UTJIT CAPITAL COST OF STRUCTURE^ 1.62 1.99 2.1+3 a Assumed length is 2 years. I of construction period for dams in the Upper Putah Creek Basin b Does not include costs of acquisition of lands and improvements, relocations of roads, and reservoir clearing which were estimated individually for each site. -Ikk- General Engineering Properties of Geologic Formations The materials comprising the various geologic formations of the Upper Putah Creek Basin display ■vri.de variations in composition, texture, and strength, which determine their suitability for use in liydraulic structures. In general, these characteristics depend on their geologic history. A generalized description of engineering properties such as vorkability, stability of cut-slopes, foundation conditions, and possible uses of materials of the various geologic forroations of the Upper Putah Creek Basin are presented in Table 2k. The general location of these formations is shovm on Plate h. 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Q,f-f 4) ft ft O rH O O o o o O rH O •• H •-{ rH O 4J r-i r-i W -P-^N W CO CO -P C CO CO c o ■H ■P (d ;^^ 0) (d • • •4 C c o o ■H O o ^ •H -P •H •H +> +> (d 4) T3 ■P 4-> pi g n > 4-> 4) (d Cd fci g Cd > ■P (« cd O t< -H Cd cd ■H o o X 4) 3 o o iH M X 4) -o cr X X •H 4^ a> 4) O 4) 41 4) P 5 c x; C E Eh o a a O ^ X E O M a u g O bO O a E -P C O -H g 8 1^5 o g § O 40 4J O -P +0 •^ Mtd O -ri rH cd •g cd x; ra >S, bOcd O -H rH cd cd 00 rH XI » a LTVrH XI w X o a. E O 1 rH -p ■p 1 C ft O -H J3 tH -h ra I I T3 rH 43 ra 0) 4) ra o 3 ra •H ti (1) -H ra j-> > XI cd C -H >-3 1 ■H C 73 E O > P.Vh C (U (d>-3 •H x; ft C 1-3 C 4) o 3 c >. C X 3-H OJ -P^ ra x^ o t< -H 4j G ra 500 people during the next 60 years. For the most part, this population expansion can reasonably be expected to take place on lands classified as irrigable. Under full development, it is esti- mated that the average annual water requirement in the service area would range from about 10,000 to 13,500 acre-feet, depending upon the types of crops being irrigated and the amount of irrigable Isind devoted to urban use. In Chapter II it was estimated that the most likely value of fu- t\ire water requirements in the service area would range from about 8,700 to 11,000 acre-feet per yeay depending upon the adequacy and reliability of the presently developed supply. In addition to water conservation, the Dry Creek site has a considerable potential for outdoor recreation. Although much of the terrain surroxinding the reservoir is steep, areas could be leveled to provide facilities for swimming, picnicking, boating, and fishing. A toixjgraphic map of the dam and reservoir site was prepared by photogrammetric methods at a scale of one inch equals 300 feet, with -151- 20. Lower reaches of Dry Creek drainage area. Artist's illustration shows location of the proposed Dry Creek Dam. St. Helena Creek diversion dam site. Waters diverted from this stream wo\ild augment the yield obtainable from Dry Creek Reservoir. -152- a contour interval of 10 feet. Reservxsir areas, storage cap>acities, suid estimates of required quantities of construction materials for the dam were computed from this map. United States Geological Survey quadrangles, at a scale of l:2i;,000 with a UO-foot contour interval, were utilized to select the location and estimate the cost of the diversion and feeder csuial from St. Helena Creek. Studies of Dry Creek Dam and Reservoir included the evaluation of three alternative ajces for the dam. The middle axis appears to be the most favorable for all but the minimum amount of storage and has been selected for presentation in this bulletin. The upper axis, about 1,200 feet upstresim, appears to be the most favorable for reservoirs of less than U,000 acre-feet storage. This axis is presently being considered by the Middletovn County Water District. Location of the. Dry Creek Dam and Reservoir site and a possible feeder canal from St. Helena Creek is shown on Plate 5- The stream bed elevations at the Dry Creek Dam site and the St. Helena diversion site are about 1,170 and 1,3'tO feet, respectively. The Dry Creek Dam site appears to be suitable for an earthfill structure of moderate height. Bedrock consists of Franciscan graywacke, chert, and shale with lesser amounts of schist, greenstone, and basalt. These rocks are generally interbedded, strike approximately normal to Dry Creek, and dip steeply from about 60 degrees downstream to almost vertical. Outcrops of fractured and weathered bedrock occur at the base of the left abutment and locally on the slopes of each abutment. Major faulting at the dam site is not indicated but evidence of four minor fault zones was observed. One fault is located on the right abutment ■153- and crosses the axis about I30 feet above stream bed. Two others are lo- cated in saddles above the left abutment. The fourth fault crosses the left abutment about 50 feet above stream bed and probably would require si>ecial treatment in the foundation area to prevent excessive leakage. Foundation preparation would include moderate stripping of soil sind weath- ered bedrock on both abutments and excavation of alluvial sands, gravels, and weathered rock in the channel section. Grouting would be required in areas of jointed bedrock. The spillway should be capable of safely passing an inflow flood with a peak discharge of about 10,000 second-feet. It appears that a concrete-lined chute- spillway across the left abutment near the end of the dam would have a suitable foundation. Bedrock at the St. Helena Diversion dam site, located in Sec- tion 26, TION, R7W, consists of serpentine of Jurassic age and is almost continuously exposed, except where it is covered by the road fill for State Highway 29. With proper treatment of the foundation area, this site appears to be suitable for a low diversion structure. Stripping for a low concrete diversion structure should include all road fill mate- rial and jointed and slightly weathered serpentine. With proper precau- tions, the road fill could be replaced along its present alignment. The alignment of the feeder canal would be i)artially in serpentine and parti- ally in graywacke, shale, and associated rocks of the Franciscan group. These rocks are exposed locally along the conduit alignment but are gen- erally covered by residiml soil and slope wash. Adequate quantities of construction materials may reasonably be exi>ected to be found within five miles of the dam site. Pervious and -l^k- ^ impervious fill materials shovild be available from alluvial deposits along Dry Creek. Numerous potentieLL quarry sites for riprap are to be foxind near the dan site. The watershed of Dry Creek tributary to the site consists of about Q.k square miles of heavy brush and wooded lands. The runoff of Dry Creek since May 1959 indicates a mean annual runoff of 22,^+00 acre-feet. i/ This flow could be augmented by gravity diversion from St, Helena Creek. The drainage area of St. Helena Creek above the diversion is about 7.7 »quare Biles with an estimated mean annual runoff of 14,500 acre-feet. Estimates were made of the amounts of water susceptible to diversion from St. Helena Creek for four sizes of conduit: 25, 50, 75, and 100 second-feet, respectively. Mean daily flows at the diversion site were assumed to occur in a similar pattern to recorded daily flow at Kelsey Creek and in direct proportion to the ratio of the mean estimated annual, runoff of St. Helena Creek to Kelsey Creek. The estimated minimum, mean, and majcimvm annual quantities of water that could have been diverted by the four sizes of diversion conduit are presented in the following tabulation: Conduit capacity, Estimated annual quantities of in second-feet divertible water, in acre -feet Minimvnn Mean Maximum 25 2,300 5,800 9,800 50 2,500 7,700 lU,600 75 2,600 9,100 19,500 100 2,600 10,000 22,500 TJ Measured at U.S.G.S. gaging station "Dry Creek near Middletown" about 600 feet upstream from the middle ajcis of the Dry Creek Dam site. -155- Yields for various sizes of reservoirs were determined by sesii- annual operation studies utilizing estimated diversions from St. Helena Creek combined with the estimated runoff of Dry Creek. These estimated yields are presented in Table 25. TABLE 25 ESTIMATED ANNUAL YIELD OF DRY CREEK RESERVOIR Estimated firm annual yield, in acre -feet Reservoir With With diversion. at indicated capacity. storage Dry Creek in cubic feet per second capacity. • • : in acre-feet only 25 • 50 • 75 : 100 2,200 2,300 2,600 2,600 2,600 2,600 it, 200 U,200 5,300 5,300 5,300 5,300 6,600 6,1+00 8,200 8,300 8,300 8,300 9,900 8,600 11,100 11,200 11,200 11,200 ll+,000 10,700 13,500 13,800 U,000 lJ+,000 Reconnaissance cost estimates were made for several heights of dam at the Dry Creek dam site, for a diversion dam on St. Helena Creek, and for a 25 second-foot feeder canal. A rolled earthfill structure with 3:1 upstream and downstream slopes for all heights of the Hiain dam was assumed. It was assumed that the dam would be 10 feet in height sund a- bout 50 feet in length. The feeder conduit would extend about 7 miles in a northwesterly direction, from the diversion dam. About 4,000 feet of either elevated or benched flume would be required in problem areas along the canal route. The capital cost of the Dry Creek dam and reservoir alone would range between about one million and k.6 million dollars depending on height of structure. With the addition of the St. Helena Creek diver- sion works, these capital costs would be increased about $380,000 and the total would then range between about 1.3 and five million dollars. -156- A sxjmmary of the estimated capital costs, average annvial costs, and unit costs of water for various sizes of dam and reservoir are presented in Table 26. Costs for various heights of dam, which include the costs of the St. Helena Creek diversion dam and feeder canal, are presented in Table 2?. It should be \inderstood, in this and all subsequent estimates of unit cost of water, that the costs shown are unallocated costs. In a reservoir serving more than one pxirpose, a i>ortion of these costs may be exi)ected to be allocated to its other functions such as recreation and/or flood control. This wo\ild tend to reduce the estimated average annual unit cost allocated to conservation water by some factor which cannot be computed iintil a final project formulation and design is made and all costs allocated. -157- TABLE 26 SUMMARY OF RECONNAISSANCE ESTIMATES OP COSTS AND YIELDS FOR DRY CREEK DAM AND RESERVOIR Height • • Normsil of dam ' water above • surface ' Storage stream elevation capacity, bed, in USGS datum, in feet ' Xn f^e% ■^cre-Xeqt : Cost of dam euid : reservoir : : Average Estimated: Capital : annual firm :cost, in: cost, in annual : millions: thousands yield, in: of : of 80 : Estimated average : annual unit cost : of vater at dan^ :Per acre-: Per acre- : foot of : foot of : firm :incrementa : annual :firm annua : yield, in: yield, in : dollars : dollars l,2li2 2,200 2.300 1.0 ^9 100 1,262 U,200 U,200 1.5 75 120 1,282 6,600 6,400 2.2 113 21 18 18 Ik 17 24 140 1,302 9,900 8,500 3-2 16k 19 160 1,322 iU,ooo 10,700 4.6 231 22 31 1/ Based on \ina1 1 ocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be cheirgeable to such functions cannot be determined until final project formulation and design are completed. -158- TABLE 27 SUMMARY OF RECONNAISSANCE ESTIMATES OF COSTS AND YIELDS FOR DRY CREEK DAM AND RESERVOIR (Including St. Helena Creek Diversion v;orks)i/ Normal water surface elevation USGS datum, in feet : : Estimated cost of : : :dam, reservoir, and: : ; diversion works ; : : : Average : Estimated: Capital : annual Storage : firm :cost, inrcost, in capacity,: annual ;mi 11 ions ; thousands in :yield, in: of : of acre-feet :acre-feet:dollars : dollars Estimated average annual unit cost of water at dam£/ :Per acre-: Per acre- : foot of : foot of : firm : incremental : annual :firm annual :yield, in: yield, in : dollars : dollars 100 1,21+2 2,200 2,600 1-3 68 1,262 1^,200 5,300 1.9 9k 26 18 10 120 1,282 6,600 8,200 2.6 132 16 13 16 lltO 1,302 9,900 11,100 3-5 179 16 28 160 1,322 iU,ooo 13,500 5.0 250 19 1/ Feeder canal capacity, 25 second-feet. 2/ Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other fvinctions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design axe completed. -159- Mlddletovn Dam and Reservoir The Middletown dam site is located in Lake County on Putah Creek, about 3^ miles north of Middletown, in Section 15, TUN, R7W, MDB&M. An alternative site, 1,600 feet upstream, was rejected because of unfavorable geologic conditions. Another alternative site, the Putah Creek Canyon site located 0.6 miles downstream, is discussed in a sub- sequent portion of this chapter. Two sites on the adjacent Crazy Creek drainage area were also considered as possibilities for off-stream stor- sige of Putah Creek waters in conjunction with the Middletown and Putah Creek Canyon sites. The lower site on Crazy Creek was rejected due to unfavorable geologic conditions. The upper site could be operated in conjunction with storage at the Middletown site emd is presented as part of this discussion. The Crazy Creek dam site is located about 2 miles northeast of Middletown near State Highway 53, in Sections 30 and 31, TllN, R6W, MDB&M. Location of the Middletown and Crazy Creek dam and reservoir sites are shown on Plate 5« Construction of the Middletown Dam and Reservoir, either with or without off-stream storage at Crazy Creek, would permit conservation of the winter storm runoff of Putah Creek and wo\ild supply supplemental water for gravity distribution to irrigable lands in the Coyote Valley service area. Of the U,600 acres of land in the potential service area, about ^+00 acres are presently irrigated and an additional net area of 1,900 acres is considered suitable for irrigated agriculture. These additional lands, under full development, would require from 3,600 to 5,300 acre-feet of water annioally, depending on the types of crops being irrigated. In Chapter II, it was estimated that about ij-^OOO acre-feet -l6l. represents the most likely value of additional anniial water requirement. This value, when added to the present requirement of 1,1+00 acre-feet, results in a total future average ann\aal water requirement of about 5,^0 acre-feet. Conserved waters could also be pumped, at added cost, to supply demands in the Collayomi-Long Valleys area, previously described in the presentation of the Dry Creek Project. The drainage area of Putah Creek above the Middletown site is Sj .h sqiiare miles. Although records of runoff are not available at the site, it is estimated that the mean annual runoff is about 103,000 acre-feet. A dam at the Middletown site was considered in The California Water Plan to serve local needs under ultimate conditions of development. Under that plan, a reservoir with a normal pool elevation of 1,080 feet, a storage capacity of lU,200 acre-feet, and an estimated annual yield of l6,000 acre-feet would have been provided. It was estimated that this reservoir, together with the yield from Detert reservoir plus utilization of ground water, would have been capable of meeting the ultimate require- ments of the Middletown area. However, because of possible drainage and mosquito breeding problems near Middletown, it was assumed for the purpose of this investi- gation, that the maximum feasible storage level at this site would be elevation 1,066 feet. At this elevation the reservoir would have a stor- age capacity of only 5^600 acre-feet. Because the reduced yield would be smaller than the combined water requirements of Coyote, Collayomi, and Long Valleys, consideration was given to off-stream storage on Crazy Creek. -162- Runoff at the Crazy Creek site is considered neglibible in comparison to that of Putah Creek. In addition to water conservation, the Middletown Reservoir could provide some recreational use to local residents and recreationists visiting the Cobb Mountain resort area. A topographic map of the Middletown eind Crazy Creek dam and res- ervoir sites was prepared by photogrammetric methods at a scale of one inch equals 300 feet, with a contour interval of 10 feet. Reservoir areas, storage capacities, and estimates of required quantities of con- struction materials were computed from this map. Stream bed elevation is about 1,020 feet at the Middletown dam site and about 1,000 feet at the Crazy Creek dam site. The two reservoir areas are separated by a saddle with natural ground elevation of 1,075 feet so that the ability of the off-stream storage reservoir to regulate Putah Creek ninoff can be preset by placement of a suitable control structure at this point. Based on a brief geologicsil reconnaissance, the Middletown and Crazy Creek sites appear to be suitable for construction of earthfill structures of moder- ate height. At the Middletown dam site, the maximum feasible height would be limited to about 60 feet because of a narrow ridge forming the right abutment, which might be subject to excessive leakage imder high heads and the necessity of controlling surcharge storage encroachment near Middletown during periods of flood runoff into a full reservoir. The Middletown dam site is underlain by hard to moderately hard, bedded sandstone and shale of Cretaceous age. Bedrock is exposed on the right abutment in large jointed outcrops, but exposure elsewhere -163- is poor. Recent alluvium fills the active channel and forms a terrace 90 feet in width at the base of the left abutment, with an estimated average depth of 20 feet and maximum depth of ^+0 feet. Foundation preparation of the abutments would require moderate depths of stripping for removal of soil and loose rock. In the channel section, removal of the entire terrace deposits probably would be required and stripping in the cut-off area should be extended to bedrock. Off-stream storage at the Crazy Creek site would be accomplished by construction of a dam and an equally sized dike. The dike site has a 200-foot wide chainnel section and rather uneven abutments. Gabbro brec- cia would underlie the main dam and the left abutment of the dike. The right abutment of the dike is composed of shale with occasional sandstone interbeds. Recent alluvium and slopewash fill the valley flats auid chan- nel sections at both the dam and dike sites. Fo\mdation preparation for the dam on Crazy Creek would require moderate stripping of alluvium with a few feet of bedrock shaping in the channel section. The left abutment would require moderate stripping of soil with additional hardrock shaping for the impervious section. It ap- pears that at least 10 feet of stripping would be required for the right abutment and some subs\irface materials testing will be required to ade- quately appraise foundation conditions. Moderate to heavy stripping of alluviimi would be required in the cheinnel section. Spillway placement would be dependent on whether Middletown Efeun and Reservoir were built alone, or in conjimction with the Crazy Creek -16k ■ Reservoir. The spillway for the Middletown site along could be construc- ted across the narrow ridge of the right abutment where depth to sound rock is about 10 feet. A lined chute spillway would be required. The spillway would be placed in a saddle leading to Crazy Creek Reservoir. Waters frcan Putah Creek would first fill the storage in Mid- dletown Reservoir and would then spill excess water ajid flood riinoff into Crazy Creek Reservoir. A lined chute spillway on the hill between the dam and the dike at the Crazy Creek Dam site would adequately discharge an inflow flood of about 52,000 cubic feet per second. The cut in the saddle between the two reservoir areas woxild re- quire a weir and a lined discharge channel into the Crazy Creek Reservoir area. The saddle is underlain by shales of Cretaceous ajid Jurassic ages of the Knoxvllle group. These are separated by a serpentine intruded fault zone. Firm rock in the shales may exist only at considerable depths. Subsuirface exploration is needed to ascertain the foundation conditions. It appears that some over-excavation and backfilling with concrete would be required at the weir between the two reservoir areas. Sufficient quantities of peirvious materials could be obtained from alluvial deposits along Putah Creek. Impervious materials may be obtained from soil and slopewash within one mile of the dam sites. Po- tential quarry sites exist in a massive sandstone bed about one-half mile upstream from the Middletown dam site. Rock would aJLso be available from spillway excavations. ■165- Reconnaissance cost estimates were made for several heights of dam at the Middletown site. Cost estimates were also made for a dam 60 feet in height at the Middletown site, combined with various heights of dam at the Crazy Creek off-stream storage site. A freeboard allowance of ll|^ feet was used for both reservoirs in estimating the reservoir capa- cities. Although no costs are included for distribution systems to the service areas, it should be noted that outlet works at both Middletown and Crazy Creek dams would be required to dewater the storage in each reservoir. Two outlets wo\ild also facilitate the service of water to irrigable areas of Coyote, Collayomi, and Long Valleys. The distribution system to farmers ' head gates would thus be shorter and would res\ilt in less channel loss and lowered maintenance costs. The capital cost of the Middletown project alone would range from $500,000 to $900,000 depending on height of structure. Capital costs for the combined Middletown-Crazy Creek project would range from $1,700,000 to $2,700,000 depending on the height of Crazy Creek dam. These costs in- clude an allowance for reqiiired relocation of parts of State Highway 53 and Big Canyon Creek road. A summary of the estimated capital cost, aver- sige annxial costs, and unit cost of water for various sizes of dam and reservoir at the Middletown site is presented in Table 28. Similar cost data for the combined Middletown-Crazy Creek project are presented in Table 29. It shoiild be remembered that these are \inallocated costs as described in the discussion of the Dry Creek Reservoir. .166- TABLE 28 SUMMARY OF RECONNAISSANCE ECTIMATES OF COSTS AND YIELDS FOR MIDDLETOWN DAM AND RESERVOIR Cost of dam aiiS" reservoir Height of dam above stream bed, in feet Normal water surface elevation uses datum, in feet Storage capacity, in Estimated average annual unit cost of water at damjy : : : Average :Per acre-: Per acre- :Estimated: Capital : annual : foot of : foot of : firm :cost, in:cost, in : firm : incremental : annual :millions: thousands: annual :firm annual :yield, in: of : of :yield, in: yield, in acre -feet: acre -feet: dollars : dollars : dollars dollars 50 1,056 2,800 2,300 0.5 2k 10 55 60 1,061 1,066 U,100 3,700 5,600 5,600 0.6 0.9 32 hi 8 8 1/ Based on \mallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such fxinctions cannot be determined until final project formulation and design are completed. .167- TABLE 29 SUMMARY OF RECONNAISSANCE ESTIMATES OF COSTS AND YIELDS FOR MIDDLETOWTJ DAM AND RESERVOIR IN CONJUNCTION WITH VARIOUS SIZES OF OFF -STREAM STORAGE RESERVOIR ON CRAZY CREEK Crazy Creek Dam and Reservoir Combined Mi ddletown -Crazy Creek Project Height of dam above stream bed, in feet Cost of dams and reservoirs Normal water surface elevation uses datum, in feet Storage capacity in 1/ acre -feet :Estimated : firm : annual :yield, in : acre -feet ; : Average ; Capital : annual ;cost, in:cost, in ;millions :thousands ; of : of ; dollars : dollars Estimated average annvial unit cost of water at dam §/ Per acre- foot of firm annual : yield, in: dollars : : Per acre- : foot of : incremental :firm annual yield, in dollars 50 1,036 7,100 7,300 1.7 86 12 60 l,0l4^ 8,600 9,100 2.0 103 11 9 70 1,056 10,100 10,800 2.3 118 11 9 80 1,066 12,100 13,000 2.7 137 10 1/ The height of the Crazy Creek Dam would not affect the storage capacity of Middletown Reservoir. Middletown Reservoir would have a storage capacity of 5,600 acre -feet, which would be established by a spillway between the two reservoirs at an elevation of 1,066 feet. 2/ Based on lonallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design are completed. -168- Putah Creek Canyon Deun and Reservoir The Putah Creek Canyon dam site is located in Lake Coimty about four miles north of the town of Middletown in Section l4, TllN, R7W, MDB&M. The site is on Putah Creek, about one-half mile below its conflu- ence with Big Canyon Creek, emd 0.6 miles below the alternative Middle- town dam site. The potential service area and water requirements are the same as those previously described for the Middletown site. Similar to Middletown reservoir, this reservoir would be suitable for conjunctive operation with off- stream storsige on Crazy Creek. With stream bed ele- vation at 995 feet, the Putah Creek Canyon site affords moire storage ca- pacity, a larger drainage area and mesui annual rujioff , larger irrigation yield, and is competitive with the Middletown site in certain capacity combinations with the off-stream storage site on Crazy Creek. In addition to water conservation, the Putah Creek Canyon res- ervoir has a somewhat better recreational potential- than the Middletown site. The reservoir surface area would be larger than that of Middletown Reservoir and would be suitable for high speed boating and water skiing. Topographic maps of the Middletown-Crazy Creek project, at a scale of one inch equals 300 feet, also covered the Putah Creek Canyon dam and reservoir site. Reservoir areas, storage capacities, and esti- mates of required quantities of constmction materials were computed from this map. Location of the Putah Creek Canyon-Crazy Creek project is shown on Plate 5« Based on a brief geologic reconnaissance, the Putah Creek Can- yon Dam site appears to be suitable for an earthfill structure of moder- ate height. The channel is about 300 feet wide at the site and is bounded -169- by steep abutments. The abutments are covered by soil and slopewash with outcrops of weathered and jointed sandstone and shale of Cretaceous age. The broad channel section is filled by recent alluvium to an estimated average depth of 50 feet. Foundation preparation would include moderate stripping of soil and weathered bedrock on the abutments. In the channel section stripping would be considerable to insiire proper cutoff but could be moderate under the pervious section, provided, after testing, that the alluvixm is found to be suitable as a foundation material. The spillway should be capable of passing an inflow flood with a peaJc discharge of about 6k,000 cubic feet per second. For Putah Creek Canyon dam and reseirvoir alone, a lined chute spillway on the left abut- ment with a cut conveyance channel and re-entrance 500 feet downstream would be adequate. A freeboard allowance of 20 feet was used in estima- ting storage capacity of the reservoir. As in the case of the Middletown dam, when Putah Creek Canyon site is considered in conjunction with Crazy Creek reservoir, a weir would be installed in the saddle between the two reservoir areas and the spillway would be placed on the hill between the main dam and dike at the Crazy Creek site. In this case, a total free- board allowance of ik feet was used in estimating combined storage capa- city of the two reservoirs. In order to utilize this storage capacity, outlet works at both Putah Creek Canyon suid Crazy Creek dams woiild be req\ilred. Construction materials are available in the vicinity of the Putah Creek Canyon site. The geology sind availability of materials for the Crazy Creek off-stream storage portion of this project has been -170- presented previously in the discussion of the Mlddletown dam and reser- voir site. There are no records of runoff for the 85.3 square miles of drainage area above the Putsih Creek Canyon dam site. The watershed above the site drains about 75 percent of the total drainage above the United States Geological Survey gaging station, "Putah Creek near Guenoc", and is estimated to produce about 86 percent of the 50-year mean annual run- off at the gage. Therefore, it is estimated that mean sinnual runoff at the dam site would be about 12^,000 acre-feet. Reconnaissance cost estimates were made for several heights of dam at the Putah Creek Canyon site (and for an 85-foot dam) in conjunc- tion with various heights of dam at the Crazy Creek off-stream storage site. Rolled earthfill structures with 3:1 upstream aad downstream slopes were used to estimate costs for all sizes of dams considered. The capital cost of the Putah Creek Canyon project alone woxild range between $1,000,000 and $1,600,000 depending on height of structure. The capital cost of the combined Putah Creek Canyon-Crazy Creek project wo\ild range from $2,300,000 to $3,300,000 depending on height of Crazy Creek dam. A summary of the estimated capital costs, average annual costs, and unit cost of water for various sizes of dam and reservoir at the Putah Creek Canyon site is presented in Table 30. Similar cost data for the combined Putah Creek Canyon-Crazy Creek project are presented in Table 31. These cost figures are unallocated costs as presented in the discussion of Dry Creek Dam and Reservoir. -171- TABLE 30 SUMMARY OF RECONNAISSANCE ESTIMATES OF COSTS AND YIELDS FOR PUTAH CREEK CANYON DAM AND RESERVOIR : Cost of dam and : Estimated avereig : reservoir : annual ur : of water lit cost at dam ' Height of dam Normal water :Estimated : Capital : Average annual :Per acre-: : foot of : Per ac3 foot f above stream surface elevation storage capacity : firm : annual :cost, in: : millions: cost, in thousands : firm : : annual ■ increme:! firm anjx bed, in feet USGS datiim, in feet in acre -feet : yield, in : acre -feet : of : : dollars : of dollars ryield, in : dollars yield, Li dollas 75 1,050 3,300 2,800 1.0 50 18 8 80 1,055 i^,750 1^,300 1.2 62 Ik 10 85 1,060 6,200 6,000 1.6 79 13 1/ Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design are completed. -172- TABLE 31 SUMMARY OF RECONNAISSATJCE ESTIMATES OF COSTS AND YIELDS FOR PUTAH CREEK CAJIYON DAiM AND FlESERVOIR. IN CONJUNCTION WITH VARIOUS SIZES OF OFF-STREAM STORAGE RESERVOIR ON CRAZY CREEK urazy CreeK uam and Reservoir Combined Putah Creek Canyon -Crazy Creek Project : : Cost of dams and : Estimated average Normal : : reservoirs : eumual unit cost . : : : : of water at dams tl Height : : : Average :Per acre-: Per acre- of dam water :Estimated:Capital : annual : foot of : foot of above surface Storage : firm :cost, in: cost, in : firm : incremental stream elevation capacity : annual : millions: thousands: annual :firm annual bed, in USGS datum. in 1/ :yield, in: of : of :yield, in: yield, in feet in feet acre -feet: acre -feet: dollars : dollars : dollars : dollars iiaf : 50 60 70 80 1,036 10,200 10,900 2.3 l,0U6 11,700 12,500 2.7 1,056 13,200 14,100 3.0 1,066 15,200 16,100 3.3 119 135 150 169 11 11 11 10 10 9 9 1/ The height of the Crazy Creek Dam woxild not eiffect the storage capacity of Putah Creek Canyon Reservoir. Putah Creek Canyon Reservoir would have a storage capacity of 8,700 acre-feet, which would be established by a spillway between the two reservoirs at an elevation of 1,066 feet. 2/ Based on xmallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation auid design are completed . -173- 22. Putah Creek at Middletown dam site. Artist's illustration shows approximate location of proposed dam. 23. Coyote Creek dam site and reservoir area — a possible surface storage project to serve Coyote Valley. Because of the limited drainage area and runoff, this project vould require a diversion from nearby Big Canyon Creek. -17^- Coyote Creek DBm and Reservoir The Coyote Creek Qam site is located in Lake Coimty on Coyote Creek, about five miles northeast of Middletovn, in Section l8, TllN, R6w, MDB&M. Coyote Creek Reservoir would provide off-stream storage for gravity diverted sxirplus water from Big Csinyon Creek and would be best suited for supplying supplemental water for irrigation purposes in the Coyote Valley Service Area. As previously discussed, the estimated fu- ture average annual water requirement for full developnent of the area would be about 5>^+00 acre-feet. The amount of new water development needed would be between U,000 amd 5^^0 acre-feet per year depending on the adequacy and reliability of the presently developed supply. In addition to water conservation, the Coyote Creek Reservoir has consideirable potential for developnent of day-use recreational facil- ities. Slopes s\irrounding the reservoir area are generally moderate, supporting stands of oaJt interspersed with chaparral and digger pine. Topography at the dam and reservoir site is shown on United States Geological Survey quadrangles at scales of 1:62, iKX) and l:2l+,000 with contour intervals of 50 feet and kO feet, respectively. These maps were utilized to detemine reservoir areas and storage capacities, to select the location of the diversion dam eind alignment of the conduit from Big Canyon Creek, and to estimate required quantities of construc- tion materials. Location of the Coyote Creek Dam and Reservoir site and the Big Canyon diversion works are shown on Plate 5- The stream bed ele- vation at Coyote Dam and Big Canyon diversion sites are about 1,000 smd 1,270 feet respectively. United States Geological Survey datura. Dikes would be required in three saddles for the higher sizes of dam. -175- Based on a brief geologic reconnaissance, the Coyote Creek Dam Bite appears to be suitable for an earthfill structiire of moderate height. Bedrock at the site consists of tuffaceous silty gravel of the Cache for- mation, and basalt of the Clear Lake volcanics. These formations outcrop on both abutments of the dam site and some leakage may be anticipated through the Cache sediments, especially on the left abutment. A faxilt crosses the right abutment and channel section at the dam axis. In gen- eral, foundation preparation wo\ild include moderate stripping of soil and weathered rock on both abutments and excavation of alluvial sands aind gravels in the channel section. Special treatment wo\ild be required to control leakage. The spillway should be capable of passing an inflow flood with a peak discharge of about 5^000 second-feet. For the intermediate sizes of dam, a lined spillway could be placed in a saddle about \ mile north- west of the end of the dam on the right abutment. Construction materials may be expected to be available within reasonable distance of the dam site. Impervious fill materials shotild be obtainable from the Cache formation in the reservoir area and pervious materials and concrete aggregate are readily available from alluvial deposits along Putah Creek. Basalt outcrops on the abutments appear to afford potential quarry sites for riprap. The Big Canyon Creek Diversion dam site is underlain by fairly hard shale of the Knoxville group of Jurassic age and appears to be suit- able for a low diversion dam. Stripping for a low concrete diversion structure shoiild include removal of soil, roadfill, and loose weathered bedrock. With proper precautions, the roadfill could probably be replaced -176- along its present alignment. The diversion conduit alignment would be partially in Recent terrace deposits, serpentine and Knoxville shale of Jurassic age, and in interbedded shale and sandstone of Cretaceous age. The conduit would cross a fault separating the serpentine and the creta- ceous shales and sandstones. There are no records of nonoff for the 5-5 sqvtare-mile area tributary to the Coyote Creek dam site nor for the I3.6 square-mile area tributary to the Big Ceinyon Creek diversion dam site. However, it is estimated that mean annual runoff from these drainage areas would be 4, (XX) and l6,70O acre-feet, respectively. Estimates were made of the amounts of water susceptible to diversion from Big Canyon Creek for four sizes of condviits: 25, 50, 75^ and 100 second-feet respectively. Mean daily flow at the diversion site was assumed to occxir in a similar pattern to recorded daily flow of Kelsey Creek and in direct proportion to the ratio of the estimated mean annual runoff of Big Canyon Creek to Kelsey Creek at, the United States Geologicail Survey stream gaging station near Kelseyville. The estimated minimum, mean, and maximum ann\ial amounts of water that oould be diverted by the four sizes of diversion conduits are presented in the following tabulation; Conduit capacity, Estimated annual quantities of in cubic feet per second divertible water, in acre-feet Minimum Mean Maximim 25 2,300 5,800 9,800 50 2,500 7,700 1U,600 75 2,600 9,100 19,500 100 2,600 10,000 22,500 -177- Yields for various sizes of reservoirs were determined by semi- annual operation studies utilizing estimated divertible water from Big Canyon Creek combined with the estimated runoff of Coyote Creek. The resultant yields of Coyote Creek Reservoir are presented in Table 32. TABLE 32 ESTIMATED FIRM ANNUAL YIELD OF COYOTE CREEK RESERVOIR Estimated firm annual yield, in acre-feet Reservoir storage With Coyote Creek alone With diversion from Big Ceinyon Creek at in- dicated capacity, in cubic feet ^per second capacity, in acre-feet • • • k • • 25 : 50 : 75 : 100 2,200 1,600 2,700 2,800 2,800 2,800 U,000 2,100 4,800 U,900 i+,900 J+,900 6,700 2,600 6,600 7,100 7,300 7,600 10,500 3,000 7,100 8,300 8,500 9,000 15,600 3,300 7,800 9,200 9,700 10,100 Reconnaissance cost estimates were made for several heights of dams at the Coyote Creek Dam site, for a diversion dam on Big Canyon Creek, and for the four sizes of diversion conduits. The diversion dam was assvmied to be a concrete overpour type, 10 feet in height. The di- version conduit would extend about five miles in a southeasterly direc- tion from the diversion dam to Coyote Creek Reservoir. About 1,800 feet woxild be by inverted siphon and the remaining portion woiild be by canal. A rolled earthfill structure with 3:1 upstream and downstream slopes was used to estimate costs for all heights of Coyote Creek Dam. The capital cost of the project would r^nge from about $600,000 to $3,500,000, depending on height of structure and size of conduit. It was found that the least costly water would be produced vrith a diversion capacity of 25 cubic feet per second for the smaller sizes of reservoir -178- I i omd with a diversion capacity of 100 cubic feet per second for the larger sizes of reservoir. A summary of the estimated total capital costs, average annual costs, and unallocated unit costs of water for various sizes of dam and reservoirs, including the Big Canyon Creek diversion dam and conduit, are presented in Table 33- A. discussion of the effect of allocating costs is presented in the portion of this chapter dealing with Dry Creek Etera and Reservoir. -179- TP£u: 33 SIM^IARY OF RECONNAISSANCE ESTIMATES OF COSTS AND YIELDS FOR COYOTE CREEK DAI-l AND RESERVOIR (including Big Canyon Creek. Diversion Works) : : Cost of dam, : Estimated average : : reservoir, and : annual unit cost Horrnal : : diversion works : of water at dam i/ Height : : : Average :Per acre-: Per acre- of dam water :Estimated: Capital : annual : foot of : foot of above surface Storage : firm :cost, in:cost, in : firm : incremental streaim elevation capacity : annual '.millions :thousands : annual : firm annual bed, in U3GS datum, in •.yield, in: of : of :yield, in: yield, in feet in feet acre -feet : acre -feet : dollars : dollars : dollars : dollars With diversion capacity of 2$ cubic feet per second 80 1,070 2,200 2,800 0.6 30 11 7 100 1,090 i+,000 U,800 0.9 43 9 lU 120 1,110 6,700 6,600 l.k 69 10 80 li+0 1,130 10,500 7,100 2.2 109 15 86 i6o 1,150 15,600 7,800 3.3 169 22 With diversion capac ity of 100 cubic feet per second ll* 80 1,070 2,200 2,800 0.8 ko 6 100 1,090 4,000 ^+,900 1.1 53 11 10 120 1,110 6,700 7,600 1.6 79 10 28 lij-0 1,130 10,500 9,000 2.1+ 118 13 55 i6o 1,150 15,600 10,100 3.5 179 18 1/ Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design are completed. -180- Enlarged Detert and McCreary Dams and Reservoirs Detert Dam Is located in Lake County on Bucksnort Creek about five miles east of Middletown in the southeasterly portion of the Guenoc Isuid grant. The original daa was completed in 1927> had a height of 30 feet above stream bed, a crest length of about 1,000 feet and created a storage capacity of about 1,150 acre-feet. The dam vas built by farm labor at a cost, not including farm labor, of about l*fl,000 dollars. A few years later the dam was raised 2 feet to increase the storage capac- ity to 1,700 acre-feet. The drainage area above the dam is 10.6 square miles and pro- duces sm estimated mean annual runoff of about 13,900 acre-feet. Al- though in most years the conserved waters from this reservoir have been sufficient to irrigate an area ranging from 700 to 900 acres, the firm annual yield is estimated to have been 1,700 acre-feet, an amount suffi- cient to irrigate an area of only 500 to 600 acres. Recently, to augment this supply, the present owners constructed an earthfill dam at the lower end of McCreary Lake to provide additional storage capacity to effect a greater degree of conservation of excess flows of Bucksnort Creek. McCreary Dam has a maximum height of about 13 feet and, with flashboards installed on the spillway crest to an elevation of 976 feet, forms a reservoir with a storage capacity of about 2,200 acre-feet. It is esti- mated that Detert and McCreary Reservoirs, with a combined 3>900 acre- feet of storage capacity are capable of supplying a firm annual yield of about S^'tOO acre-feet when operated coordinately. A net area of about 1,200 acres of irrigable land lies within the boundartes of the 2,200 acre potential Bucksnort Creek service area -l8l- 2k. Detert Reservoir on Bucksnort Creek. The earliest significant sur- face storage project in the area still supplies water to the Buck- snort Creek area. -tf^dH^^' 25. McCreary E&m and Reservoir. This recently constructed dam at the lower end of the natural McCreary Lake augments the water supply derived from Detert Reservoir. -182. of these reservoirs. At the time the land use survey was made, only TOO acres were mapped as then being irrigated. These lands were estimated to have a water requirement of about 2,200 acre-feet. If water service were to be provided to the remaining net area of about 500 acres of irrigable lands, the annual supplemental water requirement would be between 900 and 1,300 acre-feet, depending on the type of crops being irrigated. The most likely value of supplemental water requirement was estimated to be 1,100 acre-feet, and when added to the present requirement of 2,200 acre-feet, results in a total future average annual water re- quirement of about 3^300 acre-feet for this service area. Inasmuch as the estimated present yield from these two reser- voirs exceeds the estimated future water requirements of the service area, no future water development projects are contemplated for this area. How- ever, it is possible that, with the passage of time and experience, the actual water requirements will prove to exceed the estimated requirements and/or the actual reservoir yield will fall short of the estimated yield. In either event, there are sufficient quantities of water originating in Bucksnort Creek to meet the maximum possible water requirements of the service area. This source of water supply could be enhanced by providing additional storage capacity and thereby increase the reservoir yield. It appears that additional storage capacity could be obtained by enlarging either Detert or McCreary Reservoirs at a reasonable cost by raising their respective dams. -183- >^^ *#"^.i*%i ii%'^ 26. James Creek dam site and reservoir area — a possible surface storage project to serve a portion of Pope Valley. Waters diverted from nearby Swartz Creek would augment the yield obtainable from this project. 27. Resistant conglomerate along James Creek. This rock type has suit- able foundation properties for an earthfill dam. -I8i^- James Cr^ek Dam and Reservoir The James Creek dam site is located in Napa County on James Creek about one and one half miles north of the Aetna Springs resort in the center of Section 36, TION, r6w, MDB&M. Conserved waters from James Creek could be augmented by gravity diverted flows from Swartz Creek and would be best suited for supplying supplemental water for Irrigation pur- ixjses in the Pope Creek subarea of Pope Veilley. Of about 8,200 acres of land in the potential Pope Creek service area, about 200 acres presently receive water service for agriculture and an additional net area of 3>800 acres is considered siiitable for irrigated agriculture. These additional lands, under full development, would require from 1,100 to 10,500 acre- feet of water annually, depending on the types of crops being irrigated. The most likely value of future supplemental annxial water requirement imder full development was estimated to be about 1 ,100 acre-feet, ajid when added to the estimated present requirement of 6OO acre-feet, results in a total future average annual water requirement of about 8,300 acre- feet for this subarea. An additional net area of 2,900 acres of irri- gable land, located in the Burton-Hardin Creek service area of Pope Valley, is also susceptible to gravity service from James Creek Reservoir, but would require a more extensive distribution system. A topographic map of the dam and reservoir site was prepared by photogrammetric methods at a scale of one inch equals 300 feet, with a contour ln':erval of 10 feet. Reservoir areas, storage capacities, and required quantities of construction materials for the dam were computed from this map. United States Geological Survey quadrangles with a scale of 1:2^4-, 000 with a i+O-foot contour interval were utilized to select the .185- location and estimate the cost of the diversion dsun and feeder canal from Swartz Creek. Location of the James Creek dam and reservoir site and a possible feeder canal from Swartz Creek is shown on Plate 5. The stream bed elevation at the dam site is about 720 feet. United States Geological Survey datura. Based on a brief geologic reconnaissance, the James Creek dara site appears to be suitable for an earthfill structure of moderate height. Topographic limitations would require the construction of two dikes. The main dam, the east dike, and the east half of the west dike would be founded on conglomerate, sandstone, and shale of Cretaceous age. The west half of the west dike would be founded on silica carbonate rock of the Franc iscsin group. In general, foundation preparation for the main dam would in- clude stripping of from 3 to 8 feet of soil, slopewash, and weathered rock. Stripping in the channel would include about 10 feet of alluvium and 2 feet of rock. Moderate stripping of soil, weathered rock, and alluvium would be required for the two dikes. The spillway should be capable of safely passing an inflow flood with a peak discharge of about 7jOOO second-feet. A lined chute spillway through the ridge between the main dam and west dike would have a suitable foundation. The Swartz Creek diversion dam site, located in Section 11, T9N, r6w, at the mouth of a steep walled canyon, appears to be suitable for a low concrete structure. Stripping of about 15 feet of alluvium would be required in the channel section with moderate stripping of bro- ken shale and slide material from the abutments. -186- The alignment of the feeder csmal vould be partially in allu- vium ajid partially in serpentine, shale, and sandstone of Jurassic ajid Cretaceous age. The 2.8 miles of conduit vould include 3 siphons total- ing about 1,600 feet in length and would be founded in shale or serpen- tine which might require spread footings. There are no records of runoff for the 10.0 sq\iare mile area tributary to the James Creek dam site nor for the 5 •9 square mile area tributary to the Swartz Creek diversion dam site. However, it is esti- mated that mean annual runoff from the areas would be 13,700 and 8,000 acre-feet, respectively. Estimates were made of the amounts of water susceptible to diversion from Swartz Creek for four sizes of conduits: 25, 50^ 15) and 100 second-feet, respectively . Mean daily flow at the diversion site was assumed to occur in a similar pattern to recorded daily flow of Kelsey Creek and in direct proportion to the ratio of the estimated mean annual runoff of Swartz Creek to Kelsey Creek, at the United States Geological Survey stream gaging station near Kelseyvllle. The estimated minimum, mean, and maximum annual amounts of water that could be diverted by the four sizes of diversion conduits are presented in the following tabulation: Conduit capacity, in cubic feet per second 25 50 75 100 Estimated annual quantities of divertible water, in acre-feet Minimum 1,1*00 l,i*00 1,1+00 1,U00 Mean U,100 5,200 6,000 6,500 Maximum 7,200 10,U00 12,500 ll+,200 -187" Yields for various sizes of reservoirs vere determined by semi- annual operation studies utilizing estimated divertible vater from Svartz Creek combined with the estimated ranoff of James Creek. The resultant yields of James Creek Reservoir are presented in Table 3^» TABLE 3^ ESTIMATED FIRM ANMJAL YIELD OF JAI-IES CREEK RESERVOIR Reservoir storage capacity, in acre-feet Estimated firm annual yield, in acre-feet With James Creek only With diversion from Svartz Creek at indi- cated capacity, in cubic feet per second 25 50 75 100 2,700 2,600 3,i+00 ?,I;00 3,^00 3,Uoo U,6oo 3,900 5,700 5,700 5,700 5,700 6,900 5,300 7,200 7,200 7,300 7,300 9,700 6,i^oo 8,600 8,700 8,700 8,700 12,800 7,200 9,700 10,100 10,200 10,300 Reconnaissance cost estimates were made for several heights of dam at the James Creek dam site, for a diversion dam on Svartz Creek, and for a 25 second- foot diversion conduit. The diversion dam was assumed to be a concrete overpour type, 10 feet in height. The cajial vas assumed to be concrete lined. A rolled earthfill structure with 3:1 upstream and dovnstream slopes was used to estimate costs for all heights of James Creek Dam. The capital cost of James Creek Dam and Reservoir alone vould range from about 1.1 to 3.7 million dollars depending on height of struc- ture. With the addition of a 25 second-foot diversion canal from Svartz Creek, at an estimated capital cost of about $200,000, the total cost of the project would range from about 1.3 to 3.9 million dollars. Increasing .188. f the conduit capacity would result in only a small increase in yield and unit cost of water and, therefore, the 25 second-foot size canal is con- sidered most feasible. A summary of the estimated capital costs, average annual costs, and unit costs of water for various sizes of dam and reser- voir are presented in Table 35- Unallocated costs for these various dams, including costs for the Swart z Creek diversion works, are presented in Table 36. As with the other cost figures presented for other dams sind reservoirs, allocation of costs would reasonably be expected to reduce the estimated annual unit cost of water at the dam if other functions are included. -189- M TABLE 35 SLC'UvIARY OF RECOIvll'^ISSAIICE ESTIl-lATES OF COSTS A.ND YIELDS FOR JAMES CREEK DAI-1 Aim RESERVOIR Cost of dani : Estiinatea average and re ser^/oir : gaanual ur : of V7ater lit cost at daifi ^ Height I-'ormal : Average :Per acre- Per acre- of darn water : Estimated Capital : annual : foot of foot of above surface Storage : firm cost, in :cost, in : firm : incremental stream elevation capacity : annual millions : thousands : annual firm annual bed, in uses datum. in ryield, in of : of :yield, in: yield, in feet in feet acre -feet : acre -feet dollars : dollars : dollars : dollars 70 762 2,700 2,600 1.1 5? 21 18 80 792 4,600 3,900 1.6 79 20 21 90 802 6,900 5,300 2.1 106 20 33 100 312 9,700 6,Uoo 2.9 1^4 23 56 110 322 12,800 7,200 3.7 189 26 Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other fiinctions of the reservoir. The degree to which these costs night be chargeable to such functions cannot be determined until final project formulation and design are completed. -190- TABLE 36 SUMMARY OF RECONNAISSANCE ESTIMATES OF COSTS AND YIELDS FOR JAMES CREEK DAM AI^JD RESERVOIR (including Swartz Creek Diversion Works )i/ : : Cost of dam, : Estimated average : : reservoir, and : annual unit cost ^ Normal : : diversion works : of water at dam£/ Height : : : Average :Per acre-: Per acre- of dam water : Estimated: Capital : annual : foot of : foot of above surface Storage : firm :cost, in: cost, in : firm : incremental stream elevation capacity : annual : millions: thousands: annual :firm annual bed, in uses datum, in :yield, in: of : of :yield, in: jaeld, in feet in feet acre -feet : acre -feet: dollars: dollars: dollars : dollars 70 762 2,700 3,^0 1.3 bo 19 10 80 792 4,600 5,700 1.8 89 lb 19 90 802 6,900 7,200 2.3 113 16 26 100 812 9,700 8,600 3.1 155 18 40 110 822 12,800 9,700 3.9 199 20 1/ Diversion canal capacity, 25 second-feet. 2/ Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design are completed. -191- ^ r, I Upper Maxwell Ci-eek Dam and Reservoir The Upper Maxwell Creek dam site is located in Napa Coxinty in the Maxwell Creek canyon near the southwest side of Pope Valley in Section yj), T9N, R5W, MEB&M. Conserved water could be used for supplying supple- mental water by gravity to a portion of the estimated net area of 3>100 acres of irrigable land in the Burton-Hardin Creek service area of Pope Valley. At present, only about 200 acres of these lemds are irrigated About 1,000 acres are in nonirrigated grains. The additional average annual water requirements for these un- developed irrigable lajids would range from about 5,500 to 8,100 acre-feet depending on the type of crops grown. By adding the present water require- ment to the most likely value of future additional water requirement, the total future water requirement is estimated to be about 8,300 acre-feet per annum. The owners of the property upon which the dam and reservoir wo\ild be located, Usibelli Coal Mine Company, are planning construction of a 2,000 acre-foot storage reservoir at the site and have applied for water rights to store surplus winter runoff (Applications 18^05 and I86U7). It is the owner's stated intention to apply the yield fixjm the reservoir to about 1,000 acres of assorted crops in a conjunctive opera- tion with a ground water supply. The estimated average firm annual yield from a reservoir of 2,000 acre-feet capacity would be about 1,300 acre- feet. The site is suitable for earthfill structures up to 120 feet above the stream bed elevation. The drainage area above the site com- prises about 7 square miles and has an estimated mean annual runoff of 3,700 acre-feet. An average firm annual yield of about 2,200 acre-feet -193- could be developed from a reservoir created by this size of dam. However, approximate estimates of costs show that a dam 30 to kO feet in height would yield the most economical water. Due to the relatively small yield and limited service area, and to the land owner's interest in the private development of this site, no detailed hydrologic or cost data have been prepared for presentation in this report. The proposed reservoir cannot develop enough yield to satisfy ultimate requirements in the service area. Regardless of place of use of water developed from this site, an additional annual supply of about 6,500 acre-feet would be needed to fully develop the remaining irrigable area. -194- II Walter Springs E&m and Reservoir The Walter Springs dam site Is located in Napa County on Pope Creek about three miles northeast of the town of Pope Valley in the southwest quarter of Section 12, T9N, R5W, MDB&M. This dam was consid- ered by the United States Bureau of Reclamation, in conjunction with the Goodings dam site, as a j>a.rt of an alternative plan to the construction of Monticello Dam. Construction of a reservoir reduced in size over the one considered by the bureau would permit conservation of winter storm runoff from Pope Creek and woxild furnish, by pumping, an irrigation supply for the Pope Valley service area. The service area is topographically divided into two subareas. The Pope Creek and Burton-Hardin Creeks subareas comprise net irrigable areas of about 3>900 and 3>100 acres respectively. As shown in Chapter H, these subareas would have a combined future water requirement of about 16,600 acre-feet per year when fully developed. However, with the construction of Walter Springs Reservoir, some of the irrigable lands would be inundated. The extent of the inundation would depend upon the size of reservoir constructed. From about 155 to 500 acres of irrigable area would be inundated, depending upon the size of reservoir constructed. The inundation would reduce the estimated future water requirements of the service area by about 300 to 1,200 acre-feet per year. Topography at the dam and resei^oir sites is shown on United States Geological Survey quadrangles at a scale of l:2i»-,000 with contour intervals of 20 feet. These maps were used to determine reservoir areas and storage capacities. Quantities of construction materials were ■195- I. estimated from a topographic map prepared by the Bureau of Reclamation at a scale of one inch eqxials 200 feet with a contour interval of ten feet. A geologic reconnaisssmce survey was conducted at the Walter Springs dam site by the U. S. Bureau of Reclamation. Because their plan envisioned a large dam, up to 175 feet in height, that would actually have been a saddle dam for a dsim at the Goodings site, no spillway site geology data were developed by the bureau. A geologic reconnaissance study was made as part of this investigation to determine the most suit- able spillway location for dams from 50 to 80 feet in height. Constrric- tion of a dam higher than 80 feet, elevation 6hO feet, would inundate ejctensive areas of the irrigable valley lands and thus defeat the purpose of the project to develop the agricultural potential of Pope Valley. The preliminary geologic reconnaissance of the U. S. Bureau of Reclamation shows that the Walter Springs dam site consists of shale, sandstone, limestone, and diabase breccia of the Franciscan group of Jurassic age. The sedimentary rocks which underlie the channel and right abutment are structurally weak. These sedimentary rocks support 5 to 25 feet of slopewash. Recent alluviijm occurs in the channel as benches at the base of the abutment. Foundation preparations would include stripping of all loose debris and soil on the abutments. Removal of all alluvium in the channel and benches at the base of the abutments appears to be necessary. The spillway should be capable of safely passing an inflow flood with a peak discharge of about 24,000 cubic feet per second. A lined chute spillway on the left abutment, excavated into diabase breccia, -196- i I is proposed. Outcrops of fresh rock occur throughout the area and sound rock should exist at shallow depths. Construction materials are not readily available at the site but matenal suitable for both pervious and impervious fill are available in Pope Valley, about 1.5 miles away. Pope Creek enters a confined channel about 1,000 feet below the proposed dam site. Although this camyon appears to afford an excellent site for a concrete arch dam, no attempt was made during this investiga- tion to explore its possibilities. The arch dam could be used as an overpour spillway. If the arch dam is built an earthfill structure would be required in the saddle to the south of the canyon. If further inves- tigation is conducted in this area, the alternative arch dam site shoiild be given consideration before a final decision is reached on the most suitable site for a dam and reservoir to sei-ve Pope Valley. There are no records of r\inoff for the k6.k square miles of drainage area above the Walter Springs dam site; however, it is estimated that the mean annual runoff from the area would be about 35»0O0 acre-feet. A record of the total runoff from the Pope Valley drainage area will be available for future studies due to installation of a continuous water stage recorder on Pope Creek in December of I96O. A rolled earthfill structure with 3:1 upstream and downstream slopes with a 30 foot crest width was used to estimate costs. A summary of the estimated capital costs, average anniial costs, and vinallocated unit cost of water for various sizes of dam and reservoir is presented in Table 37. Cost of pumping the firm annual yield to an elevation of 750 feet was included so that a cost comparison with alternative gravity -197- sources of supply might be made. Capital costs include the estimated cost of a pumping plant sufficient to meet peak irrigation demands for the firm annual yield. Annvial costs include the cost of electrical energy necessary to pump the estimated firm annual yield to the 750 foot elevation. Prom this elevation any part of the service area coxild be served by gravity flow. The capital cost of the project would range be- tween 800,000 to 2.2 million dollars depending on the height of the dam. -198- TABLE 37 SUI-3-1ARY OF REC0?JNAIS3MCE E3TIKATES OF COSTS A::D YIELDS FOR V/ALTCH SPR1:;GS DA-M A:4D KESERVOir^ : : Uoiit of diXL iiutamated average IJormal I ; una reserx'oir annual unit cost of water at dami/ • • • : : : Average Height Per acre-: Per acre- of dam water : Estimated: Capital : annual foot of : foot cf above surface otorage : firrn :cost, in :cost, in firm : incremental stream elevation capacity : annual :millions tthousands annual :firm annual bed, in USGS datum, in :yield, in: of : of : acre -feet : dollars?/ : dollar s^/ yield, in: yield, in feet in feet acre -feet dcllars : dcllars 50 599 3,500 3,000 .8 60 20 10 60 609 7,250 6,000 1.2 90 15 11 70 619 ll+,000 9,600 1.7 130 Ik 10 80 629 2U,500 13,700 2.2 170 13 Ij Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design are completed. 2/ Includes capital costs of pumping plant. 3/ Includes annual cost of electrical energy required to pump firm annual yield to 750 feet, USGS datum. ■199- ^z.^-' ., .'^^-'S;^ 0't^^Mm v^v:- 28. Jurassic intrusive rock along Pope Creek about 1,000 feet downstream from VJalter Springs dam site. This massive rock vould provide a good foundation for any type structure. 29. Goodings dam site and reservoir area on Maxwell Creek in Pope Valley. -200- Goodings Dam and Reservoir The Goodings dam site is located in Napa County on Maxwell Creek about k miles east of the community of Pope Valley in Section 19> T9N, RUw, MDB&M, as shown on Plate 5. This dam site was considered by the U. S. Bureau of Reclamation in conjunction with the Walter Springs dam site as a part of an alternative plan to the construction of Monti - cello Dara. A smaller dam at the Goodings site was later included in The California Water Plan as a source of water to serve the lands in Poi)e Valley. This plan included a diversion of Putah Creek waters from the proposed Middletown Reservoir. Construction of a reservoir of reduced size would permit con- servation of winter storm runoff from Maxwell Creek and would furnish, by p\imping, an irrigation water supply for part of Pope Valley. The Burton- Hardin Creeks subarea comprises a net irrigable area of about 3>100 acres. As discussed in Chapter II, this area would have a total future annual water requirement of about 8,300 acre-feet when fully developed. However, with construction of Goodings Reservoir from 300 to TOO acres of irrigable lands would be inundated, depending upon the size of reservoir constructed. The reduced acreage would eliminate from 800 to 1,900 acre-feet of the estimated future water requirement, leaving an ultimate requirement of from 6,U00 to 7,500 acre-feet per year. The recreational potential of Goodings Reservoir would be small since the relatively flat topography of the area will tend to cause mud flats as the reservoir fluctuates during the irrigation season. Its close proximity to Lake Berryessa would also tend to limit its rec- reational potential. -201- Topography at the dam and reservoir site is shown on United States Geological Survey qiiadrangles at a scale of 1:2U,000 with a con- tour interval of 40 feet. Reservoir areas and storage capacities were determined from a plane table survey map prepared by the Department of Water Resources in 1956 at a scale of one inch equals 1,000 feet, with a contour interval of 25 feet. A U. S. Bureau of Reclamation topographic map, at a scale of one inch equals 200 feet with 10-foot contour inter- vals, was used to estimate earthwork quantities for the dam. Studies of Goodings Dam and Reservoir Included the evaluation of an alternative site located approximately one mile downstream from the Goodings site. A brief geologic reconnaissance of the lower site indicated that the upper site was more favorable. Based on a preliminary geologic reconnaissance report of the U. S. Bureau of Reclamation, the Goodings site appears to be suitable for an earthflll dam. Construction of a dam higher than 110 feet, ele- vation 630 feet, would inundate an extensive area of the irrigable lands in the proposed service area and this was, therefore, the limiting height used in the studies made during this investigation. The dam site consists of fairly steep, soil covered, abutments and a 100-foot wide chsmnel. Bedrock at the site consists of weakly ce- mented and interbedded sandstones and raudstone. The bedrock forms an anticline, the axis of which strikes parallel to the stream channel and dips into both abutments. Foundation preparation under the pervious section shoxild in- clude stripping of all loose soil. Stripping for the impervious section should be carried into fairly fresh, sound bedrock. Foundation grouting probably would be required. -202- The spillvay should be capable of safely passing an inflow flood with a peak discharge of about l6,000 cubic feet per second. A lined chute spillway on either abutment is possible. Construction materials are not plentiful near the site but the residiial soils and slopewash should provide sufficient quantities of ma- terial suitable for impervious or semipervious fill. Very limited qxian- tities of pervious fill may be obtained from Recent alluvium in the area. Potential sources of riprap and concrete aggregate were not observed near the site. "Riere are no records of runoff for the 33.3 sqioare miles of drainEige area above the Goodings Dam site; however, it is estimated that the mean annual runoff from the area would be approximately l6,500 acre -feet. A rolled earthfill structure with 3:1 upstream and downstream slopes with a 30-foot crest width was used to estimate costs. A sunmiary of the estimated capital costs, average annxial costs, and unallocated unit cost of water for various sizes of dam and reservoirs is presented in Table 38. Cost of pumping the yield to elevation 750 feet was inclu- ded in the cost estimates so that a cost comparison with alternative gravity sources of supply might be made. Capital costs include the esti- mated cost of a pumping plant sufficient to meet peak irrigation demands for the firm annual yield. Annual costs include the cost of electrical energy necessary to pump the estimated firm anntial yield to the assumed elevation of 750 feet. From this elevation, the entire sei^ce area could be served by gravity flow. A diversion conduit from Pope Creek into Burton Creek would be a means of increasing the firm annual yield of Goodings Reservoir, and should be considered if further studies of this project are contemplated. -203- TABLE 38 SUI'E.IARY OF RECOrJNAISSMCE ESTIMTES OF COSTS AND YIELDS FOR GOODINGS DAM AND RESERVOIR • Cost of dam :Estiraated average » • • • and reservoir :annual unit cost • • :of water at dami/ Height Normal • : Average :Per acre-: Per acre- of dam water rEstimated Capital : annual : foot of : foot of above surface Storage : firm cost, in :cost, in : firm : incremental stream elevation capacity : annual millions : thousands: annual :firm annual bed, in uses datum. in :yield, in of : of ,: yield, in: yield, in feet in feet acre -feet : acre -feet dollars?/ :dollarsl/: dollars : dollars 60 569 3,000 2,200 0.5 ko 18 Ik 70 579 7,000 i+,300 0.7 70 16 Ik 80 589 li^,000 6,100 1.1 95 16 25 90 599 21,500 7,100 1.5 120 17 25 100 609 33,000 8,100 1.9 145 18 25 110 619 50,500 9,100 2.3 170 19 ly' Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design are completed. 2/ Includes capital costs of pumping plant. 3/ Includes ajinual cost of electrical energy required to pump firm annual yield to 75O feet, USGS datum. -20H- Cape 11 Creek DBni and Reservoir The Capell dam site Is located in Napa County on Capell Creek, about one-half mile south of Capell Valley in Section 20, T7N, R3W, MDB&M. The location of the proposed reservoir is shown on Plate 5- Con- sideration was given to the construction of a dam and reservoir at Capell Creek dam site for the purpose of conserving surplus waters of Capell Creek for use as irrigation and domestic supplies in the Capell Valley service area. Of the 69O irrigable acres in the potential service area, only 130 acres are presently being irrigated. If water service were pro- vided for the remaining 56O acres, the annioal supplemental water require- ment would range from about 1,100 to 1,600 acre-feet depending on the types of crops being irrigated. Only about 50 percent of these Isjids can be served by gravity flow; pumping would be required in order to serve the entire valley. However, to the extent that irrigable lands are used for urban purposes, the requirements for irrigation would be reduced accordingly. AlthoTigh basin wide reconnaissance studies for surface storage possibilities were concentrated primarily on projects to serve agricul- tural needs, the reqiiirements of domestic water users were also investi- gated. Except for the ccmmunity of Middletown, the only area within the basin expected to urbanize extensively is the potential recreational and conmercial areas around Lake Berryessa. According to a recent report by the Napa Coiinty Planning Com- mission, the domestic water requirement around the westerly shore of Lake Berryessa, including Capell Valley, co\ild increase to as much as 7,500 acre-feet per year under maximum development. About U,000 acre- -205- feet of this requirement wotild be needed in the Capell Valley service area. Whether or not such a saturated degree of develoiJment vill ever be reached could not be determined during this investigation. In any event, water from Capell Reservoir covild be \ised to meet a portion of that domestic demand. The close proximity of the proposed reservoir to Lake Berryessa will tend to induce its recreational value; however, the establishment of a fishery would tend to draw some recreationlsts to the area. The Capell Creek dam and reservoir sites are shown on U. S. Geo- logical Survey quadrangles at scales of 1:62,500 euid 1:2^,000 with con- tour intervals of 50 feet ajid 20 feet respectively. These maps were utilized to determine reservoir areas, storage capacities, emd quantities of construction materials. The stream bed elevation at the dam site is about 765 feet, U. S. Geological Stirvey datum. Two alternative dam sites were considered. An upper site, re- ferred to as Upper Capell, is located approximately one mile upstream from the selected site and a lower site, referred to as Lower Cajiell, is located approximately 2,000 feet downstream. A brief reconnaissance geologic and cost study of the three Capell sites indicated that the middle site was the best of the three considered. The Capell Creek dam site consists of a steep rocky left abutment, \i narrow channel, and a long, narrow topographic bench which forms the right abutment. Bedrock at the site consists of interbedded sandstone smd shale, belonging to the Knoxville group. The sediments generally strike parallel to the dam site axis and dip very steeply both upstream and downstream. Foundation preparation would include moderate stripping of soil and weathered rock on both abutments ajid excavation of alluvial sands and gravels in the channel bottom. Special treatment would be re- quired to control leakage. -206- The spillway should be capable of passing an inflow flood with a peedc discharge of approximately 5,000 second- feet. A lined chute spillway could be placed on the left abutment. Although construction materials are not plentiful near the site, the residual soils and slopewash should provide sufficient quan- tities of material for impervious or semipervious fill. Limited quan- tities of pervious fill may be obtained from the Recent alluvium in the area. Several potential quarry sites, which could provide rock for rip- rap, exist near the dam site. There are no runoff records for the 8.3 square mile drainage area above the dam site; however, it is estimated that the mean annual runoff from the drainage area is k,600 acre-feet. Yield studies and cost estimates were made for dam heights ranging from U5 to 95 feet with a corresponding range in capacity from 800 to 6,300 acre-feet. A rolled earthfill structure with 3:1 upstream and downstream sloi>es with a 30-foot crest width was used to estimate costs for all heights of Capell Creek Dam. The capital cost of the proj- ect would range from $200,000 to $1,600,000 depending on the height of dam. A summary of the estimated capital cost, average ann\xal cost, and vmallocated unit cost of water for various sizes of dam and reser- voir are presented in Table 39» Because water consei"ved by this reser- voir might be used for either irrigation or domestic purposes, annual unit costs of water were estimated on both firm and safe yield bases, since a water deficiency cannot be tolerated in a domestic supply. -207- TABLE 39 SUMMARY OF RECOririAISANCE ESTIMATES OF COSTS AND YIELDS FOR CAPELL CREEK DAM AITO RESERVOIR Cost of dam : Estimated average and reservoir : emnual unit cost : of water at daml/ Height Normal Average :Per acre- Per acre- of dam water cEstimated Capital : annual : foot of foot of above surface Storage : firm cost, in: cost, in : firm incremental stream elevation capacity : annual millions: thousands : annual firm annual bed, in uses datum, in :yield, in of : of :yield, in yield, in feet in feet acre -feet : acre -feet dollars: dollars : dollars dollars 1^5 802 800 600 (500) 0.2 12 20 (2M 12 (15) 55 812 1,400 1,100 (900) 0.3 18 16 (20) 16 (16) 65 822 2,300 1,600 (i,Uoo) 0.5 26 16 (19) 37 (37) 75 832 3,i+00 1,900 (1,700) 0.7 37 19 (22) 70 (70) 95 852 6,300 2,500 (2,300) 1.6 79 32 1/ Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined imtil final project formulation and design are completed. * Values in parenthesis are for safe yield operation of the reservoir. -208. Adams Dam and Reservoir The Adams dam site is located In Napa County on Bticuera Creek 1,500 feet downstream from the confluence of Adams Creek in the south half of Section 22, TION, RUW, MDB&M. The stream bed elevation is ap- proximately kk^ feet, which is about five feet above the maximum pool elevation of Lake Berryessa. The drainage area above the dam site is approximately 3^ square miles and has an estimated mean soumal runoff of 17,200 acre-feet. The location of Adams dam and reservoir site is shown on Plate 5- The Adams dam site was first investigated by the U. S. Bureau of Reclamation as part of an alternative plan to the construction of Monticello Dam. It was later considered in studies made for The Cali- fornia Water Plan by the Department of Water Resources, but was not in- cluded as a part of that plan. Although basin-wide reconnaissance studies for surface stor- age possibilities were concentrated primarily on projects to serve sigricultural needs, the requirements of domestic water uses were also investigated. Except for the commtinity of Middletown, the only other area within the basin expected to urbanize extensively is the potential recreational and commercial areas around l&ke Berryessa. In order to supply these areas, which are expected to develop along the perimeter of the lake, alternative soiirces of water will become important to the local interests involved. The Adams Reservoir was considered during this investigation as a possible alternative to piunping water directly from Take Berryessa to supply the needs of future home sites, recreational, and commercial -209- developojents around the upper end of Lake Berryessa. According to a recent report by the Napa Covmty Planning Commission, the domestic vater requii*ements around the laJce, including Capell Valley, could increase to as much as 7*500 acre-feet per year under full development. Of this amount, about 2,000 acre-feet per year would be required to serve areas around the upper end of the lake. The recreation potential of the proposed reservoir would prob- ably be limited due to its close proximity to Lake Berryessa; however, the establishment of a fishery should tend to draw some recreationists. The Adams dam and reservoir site is shown on the Walter Springs 7.5 minute United States Geological Survey quadrajigles at a scale of 1:21*^,000 with a contour interval of kO feet. Reservoir areas and stor- age capacities were estimated during previous studies from a similar map. The Adams dam site was mapped topographically by the U. S. Bureau of Reclamation at a scale of one inch equals 30O feet with a 20-foot con- tour interval. This map was used for dam layout ajid to estimate earth work volvmies. One alternative to the Adams dam site, referred to as the Zim Zim dam site, was investigated. This site is located approximately l.k miles upstream from the Adams site on Eticuera Creek. Preliminary cost estimates indicated that the Adams Reservoir would provide water at a lower unit cost; therefore, the Zim Zim site was not considered further. Based on a preliminary geologic reconnaissance study made by the U. S. Bureau of Reclamation, the Adams dam site appears to be s\iit- able for the construction of an earthfill structure. -210- Bedrock at the dam site is sandstone of the Knoxvllle group. This is more or less massive, veakly cemented, ajid trends at about right angles to the proposed eixis vlth nearly vertical dip. Special treatment vould be required to control leakage. A boulder conglcanerate about 50 feet wide extends from the top of the right abutment. This probably would provide a suitable foun- dation for the spillway, which should be capable of passing an inflow flood with a peak discharge of about 22,000 second-feet. Estimated stripping depths would vary from approximately 2 feet on the right abutment to 8 or 10 feet on the left abutment. "Hie cemyon floor is relatively clear of any alluvial fill. Pervious and impervious fill should be available in svifficient quantities from the allirvial deposits along Eticuera Creek irpstream from the dam site. PtLprap would be available from potential quarry sites in the reservoir area. Yield suid cost studies were made for dam heights ranging frcwi 35 to 135 feet with corresponding capacities of 1,500 to S^^'+OO acre- feet. Quantities of fill material were based on 3:1 slopes with a 30- foot crest width. The capital cost of the project would range from $70,000 to $1,560,000 depending tipon the height of the dam. A sxommary of the estimated capital cost, annual cost, and unallocated average unit cost of water for various sizes of dam aind reser- voirs is presented in Table ^. Because water conserved by this reservoir would be used for domestic purposes, annual unit costs per acre-foot were based on a safe yield basis rather than on a firm yield basis, since a water deficiency cannot be tolerated in a donestlc supply. -211- TABLE UO SUl-'IMARY OF RECO:'I?IAISSAI>ICE ESTIMATES OF CXDSTS ATJD YIELDS FOR ADAI-IS DAM AND RESERVOIR : : Cost of dam : Estimated average : : : and reservoir : annual unit cost : : : : of water at damJ:/ Height Normal : : : Average: Per acre-: Per acre- of dam water :Estimated: Capital : annual : foot of : foot of above surface Storage : safe :cost, in :cost, in: safe : incremental stream elevation capacity : annual : thousands: hundreds: axinual :safe annual bed, in USGS datiim, in :yield, in: of : of :yield, in: yield, in feet in feet acre -feet: acre -feet: dollars : dollars: dollars : dollars 35 55 75 95 115 135 469 1*89 509 529 5^9 569 1,500 1,000 70 35 3,^0 2,100 170 85 6,600 3,500 350 180 12,700 5,500 590 300 21,700 7,000 920 1+65 3l<-,iKX) 8,400 1,560 788 3 k 5 5 7 7 5 7 6 9 23 1/ Based on unallocated costs. If flood control, recreation, or other purposes are included, a portion of these costs may reasonably be expected to be allocated to the other functions of the reservoir. The degree to which these costs might be chargeable to such functions cannot be determined until final project formulation and design are completed. -212- Comparisons of Alternative Surface Storage Projects The various possible plans for vater supply development in the Upper Putah Creek Basin must be considered from the standpoint of indi- vid\ial service areas. In considering alternative plans for supplying water to these service areas, partic\ilar attention should be given to the following factors: (l) future supplemental water requirements of potential service areas; (2) the net firm annual yield or amount of new water that woiold be developed by a particular project compared to that which could be developed by alternative projects; (3) the location and accessability of irrigable areas with respect to a project as compared with alternative projects, where cost and maintenance of a lengthy con- veyance system could be a deciding factor in project selection; (U) the capital cost of a given project compared to that of alternative projects; (5) the estimated average anni»l unit cost of water from a given project compared to that from alternative projects; (6) the average annual incre- mental unit cost of incremental yield that would be developed from var- ious sizes of structures comprising a given project; (7) payment capacity for water; and (8) benefits to be derived from the various plans for water development. In the following discussion of alternative projects for indi- vidual service areas, primary consideration is given to the unit cost of water derived from the projects, at dam and reservoir sizes consistent with the water requirements, and payment capacity within the service area. Farm budget analyses on representative crops indicate that pay- ment capacities of vineyard and deciduous orchard ci-ops exceed the expec- ted costs of developing additional water sirpplies in several localities -213- I within the basin. The estimated accomplishments and costs of alternative plans for water development may readily be determined by referring to Plates 6 through 8, which show the relationships between storage capacity, yield, and unallocated unit cost of water. The relationships shovm on these plates are preliminary, intended to show the relative merits of one project over another for various magnitudes of water supply development. Plates 6.4 and 6B show the capital cost for various capacities of reservoirs in Lake and Napa Counties, respectively. The costs represent the total cost of the dam, land acquisition, road and utility relocation, and site clearing, but do not include costs of install- ing pumping plants, diversion dams and conduits where such features would be required. Costs of these omitted facilities, however, are reflected in the unallocated average annual unit cost of water from each project. Plates 7A and 7B show the relationships between the storage capacities and firm annual yields of reservoirs in Lake and Napa Counties, respectively. Plates 8A and 8B show the relationships between annual yield and the unallocated unit cost of water from reservoirs in Lake and Napa Counties, respectively, measured at the dam. The final selection of a project to serve any of the service areas will be influenced by the degree of local interest and the ability to form agencies and finance construction and operation of water development facilitie; Collayomi-Long Valleys Service Area Several alternative plans for development of additional surface water supplies for the Collayomi-Long Valleys service area were studied during this investigation. The most promising of these included Dry Creek Reservoir, Middletown Reservoir, Putah Creek Canyon Reservoir, and Crazy -2lli- Creek Reservoir to be operated in conjunction with either the Middletown or Putah Creek Canyon reservoirs. However, Middletown and Putah Creek Canyon Reservoirs alone are not considered as true alternatives for all levels of development. For example, if an annual yield of greater than about 6,000 acre-feet is desired, it would be necessary to include an off- stream storage reservoir on Crazy Creek because of the previously discussed height limitation at the Middletown and Putaii Creek Canyon sites. During the past few years there has been active local interest in development of an additional water supply for a portion of this area by the Middletown Coxmty Water District. The District boundaries are delineated on Plate 2. At present, the District comprises a total area of about 6,300 acres, but includes only about 56 percent of the irrigable lands in the Collayomi-Long Valley service area. These irrigable lands are estimated to have an average aimual water requirement of about 6,000 acre-feet vmder full develojaient . The Community of Middletown is not included within the District boundaries. The entire Collayomi-Long Valley service area was estimated to have a net irrigable area of about U,700 acres and, when fully developed, to have an average anniial water requirement of about 11,000 acre-feet. The amount of new water supplies needed would be between 8,700 and 11,000 acre-feet per year depending on the magnitude of the present deficiency in water supply. The Dry Creek Reservoir would be capable of supplying the esti- mated future water requirements of the area, but at an estimated cost in excess of $20 per acj-e-foot. An annual yield of about 6,000 acre-feet would cost between $1? and $l8 per acre-foot. For annual yields greater -215- than 6,000 acre-feet, the unit cost of water can be substantially reduced by diverting water from St. Helena Creek. Combined firm annual yields ranging from 8,000 to 11,000 acre-feet can be obtained from these facili- ties for about $l6 per acre-foot. Plans for additional water supply development with the objec- tive of serving the entire Collayomi-Long Valleys service area, including Middletown, appear to be in the best interest of the area. In this re- spect, it might be advantageous to consider staging the construction of Dry Creek Reservoir and the St. Helena diversion works. Under this con- cept, a reservoir with a storage capacity of 8,500 acre-feet might be constructed initially at an estimated capital cost of about $2.6 million. This reservoir would provide an estimated firm annual yield of about 7,700 acre-feet at an estimated vmit cost of about $l8 per acre-foot. At such time as demands for water exceed this yield, the St. Helena di- version works with a capacity of 25 second-feet co\ild be constructed at a cost of about $0.*+ million. These works would increase the firm annual yield to a total of about 10,000 acre- feet and would reduce the overall unit cost of water to about $l6 per acre-foot for the benefit of all concerned. Referring to Plate 8A, it can be seen that reservoirs at either the Middletown or Putah Creek Canyon sites, in conjunction with off- stream storage on Crazy Creek, covild develop s\ifficient quantities of water to meet the full requirements for this service area at a \mit cost of about $11 per acre-foot at the respective dams. However, there ap- pears to be many more problems involved which coxild not be fully evaluat- ed during this reconnaissance investigation. For example, problems of -2l6- design and resultant cost of the contixsl structure between the main and off-stream storage reservoirs are not known to any degree of accuracy. Detailed studies were not made of the problems of dewatering the two sejjarate reservoirs at low stages nor of costs of required pumping and conveyance systems to deliver the water to the service area. Very rough approximations indicate that the vmit cost of water delivered to the service area, including pumping costs, would be on the order of $15 or $16 per acre-foot. Therefore, there would be no clear-cut cost advantage favoring either of the downstream reservoirs. In addition to cost considerations, much of the land that would be inundated by Crazy Creek sind the upper reaches of either Middletown or Putah Creek Canyon Reservoirs is either presently developed or is capable of being developed to a much higher degree than lands that would be inun- dated by Dry Creek Reservoir. The recreational potential is greater at Dry Creek Reservoir than at Middletown, Putah Creek Canyon, or Crazy Creek Reservoirs. It, therefore, appears that construction of a reser- voir on Diy Creek, augmented by a diversion fran St. Helena Creek, woxild be the most desirable source of surface water to meet the estimated fu- tMre water requirements in the Collayomi-Long Valleys service area. It was stated in Chapter IV, that there is a possibility for increased ground water development in certain parts of the Collayomi- Long Valleys service area. This may make possible the coordinate and conjunctive operation of Dry Creek Reservoir and ground water storage capacity. Altho\igh the magnitude amd frequency of historic flooding of Dry Creek was not studied durtng this reconnaissance investigation it -217- might be desirable to provide some flood control storage in Dry Creek Reservoir in view of the expected futtire growth of Middletown. All of the foregoing factors should be considered in future feasibility studies involving the Dry Creek site, so as to provide the greatest benefits to the greatest number of people in the Collayomi-Long Valleys service area. Coyote Valley Service Area The Coyote Valley sei-vice area is advantageously located below several of the major tributaries of Putah Creek, with the main streaa flowing through the center of the valley. The area contains about 2,300 net irrigable acres which, under full development, woxild have an average annual water reqviirement of about 5^iKX) aci*e-feet. The amount of new water supplies needed would be between 4,000 and 5,^00 acre-feet per year depending on the adequacy and reliability of the present sources of supply . Three possible reservoirs should be considered as potential so\i3?ces of additional surface water supplies to meet the future demands for water in this area. These are Middletown fteservoir, Putah Creek Can- yon Reservoir, and Coyote Creek Reservoir, with a 25 second-foot diver- sion conduit from Big Canyon Creek. Any of the thi^e sources could meet futxxre demands for water in the area. The \mit cost of water from Putah Creek Canyon Reservoir would exceed that from either Middletown or Coyote Creek Reservoirs. Although reconnaissance estimates of unit cost of water derived from Middletown Reservoir are slightly less than that derived from Coyote -218- Creek Reservoir, these two reservoirs must be considered coapetitive pending Bore thorough design and cost studies. This is perticTilarly true since Coyote Creek Reservoir has a greater potential for outdoor vater- associated recreation than Mlddletown Reservoir. The capital cost for either of these projects was estinated to be in the neighborhood of 1.0 million dollars and the unit cost of water was estimated to range from $8 to $9 per acre-foot. However, as in the case of the Collayomi-Long Valleys service area, there is a possibility for Increased gro\md water development in the central portion of Coyote Valley. It might be possible to develop ground water in s\xfficient quantities to meet the entire future water requirements of the area. In any event, future feasibility studies for water development should consider the possibility for coordinate and conjunctive oi^eration of sxirface and ground water sources as well as the recreational aspects of these reservoirs. Collaycml, long, and Coyote Valleys Service Area The possibility of combining the service areas of Collayomi, Long, and Coyote Valleys, and supplying the entire area from one large reservoir project was given consideration. The total combined service area water requirement would be about 16,^*00 acre-feet per year. The total amoxint of new water needed would be between 12,700 and l6,000 acre- feet per year depending upon the adequacy and reliability of presently developed water supplies in meeting present water requirements. Putah Creek Canyon Reservoir, with off- stream storage on Crazy Creek, could meet these requirements at a unit cost of water of from $10 -219- to $11 per acre-foot. The additional cost of pumping euid conveying water to the Collayomi-Long Valleys service area vould increase the unit cost of water to $15 or $l6 per acre- foot, or about the same cost that would apply to water taken from a Dry Creek Reservoir. Thus, there would be no advantage over the Dry Creek Project for that area. Furthermore, because surface water could be developed for use in Coyote Valley for $8 or $9 per acre-foot from the smaller independent reservoirs, such a large com- bined project would be a disadvantage to that area. Therefore, a large project for serving the entire Collayomi, Long, and Coyote VgLLley does not appear to be Justified. Pope Valley Service Area The Pope Valley service area is topographically divided into two subareas — the Pope Creek subarea and the Burton- Hardin Creeks sub- area. Four possible reservoirs should be considered as potential sources of supply to meet the future demands for water in this veuLley. These are James Creek, Walter Springs, Upper Maxwell, and Goodings Reservoirs. In some re8i)ects these sources should be considered as alternatives and in other respects they should be considered as component features of aa integrated system for serving the entire valley. For exaurple, for annual yields up to about 9,000 acre-feet, the James Creek, Walter Springs, and Goodings Reservoirs may be considered as alternatives. However, because the future requirements of both subareas exceed 9,000 acre-feet, it be- comes obvious iq>on examination of Plate 8b that either a large reservoir at the Walter Springs site or a combination of two or more reservoirs must be considered if full development of the area is to b** achieved. -220- The Pope Creek subarea was estimated to have an average annvial water requirement of about 8,300 acre-feet when fully developed. The alternative projects considered as possibilities in meeting this require- ment are James Creek Reservoir, with a 25 second-foot diversion conduit from Swartz Creek, emd Walter Springs Reservoir. Construction of James Creek Reservoir without the Swartz Creek Diversion would not satisfy the full requirements of the area and water derived therefrom would be more costly than that derived with the diversion conduit. For annual yields up to about 6,000 acre-feet Walter Springs Reservoir and James Creek Reservoir, with diversion from Swartz Creek, may be considered competitive. After construction of such facilities the unit cost of water would be between $15 and $l6 per acre-foot. Above this level of development, the unit cost of water derived from these two sites diverges rather rapidly. Unit cost of developing svifficient yield to meet the total futxir« anntial requirement of 8,300 acre-feet for this subarea would be between $lU and $15 per acre-foot at the Walter Springs site whereas it would be between $17 and $l8 per acre-foot at the James Creek site. These costs appear to be within the range of payment capac- ity of orchard ajid vineyard crops grown in this area. The Burton-Hardin Creek subarea was estimated to have an aver- age annual water requirement of about 8,300 acre-feet when fully devel- oped. The alternative projects considered as possibilities in meeting this requirement are Goodings and Walter Springs Reservoirs. Both proj- ects would require considerable pumping. Although not considered as an alternative, private interests are planning to build a small dam and -221- reservoir at the Upper Maxwell Creek site. If this reservoir is built as planned, about 1,300 acre-feet of the requirements in this subarea would be satisfied and the yield needed from Walter Springs or Goodings Reservoir would be reduced accordingly. For annvial yields txp to about 6,000 acre-feet Walter Springs and Goodings Reservoirs may be considered competitive. At this level of develojHnent the cost of water would be between $15 and $l6 per acre- foot. Above this level of develoixnent , the tinit cost of water derived from these two sites diverges rather rapidly. For a yield of 8,300 acre- feet, the unit cost would be between $lU and $15 per acre-foot at the Walter Springs site and about $l8 i)er acre-foot at the Goodings site. Unit cost of water is not the only consideration in selecting a plan for water develoiment. Both the Walter Springs and Goodings Reservoirs would require extensive pimrping while deliveries from James Creek Reservoir woTild be by gravity. Even though cost figures were in- tended to reflect this difference, a gravity supply is often more attrac- tive from a simplicity, reliability, and maintenance viewpoint. Also, both the Walter Springs and Goodings Reservoirs would inundate a sizable portion of the irrigable lands within their respective service areas, while inxindatlon of irrigable lands by James Creek Reservoir woxild be negligible . -222- The relative amounts of this inundation for Walter Springs and Goodings Reservoirs are shown in the following tabulation: Comparison of Areas Inundated for Various Levels of Develoiment Name of reservoir Walter Springs Goodings Firm annual Approximate Approximat( 2 area yield, storage capacity. inundated, ■ In acres In acre-feet in acre-feet Total 500 Net Irrigable 6,000 7,300 150 7,000 8,900 600 200 8,000 10,700 700 300 13,700 2i|,500 l,i+00 500 6,000 13,^+00 700 300 7,000 21,U00 1,000 500 8,000 32,300 1,400 700 From a viewpoint of unit cost of water and area Inundated it would appear that the Wailter Springs site is the most favorable alter- native for either the Pope Creek or Bvirton-Ha]*dln subareas. However, Walter Springs Reservoir would be centrally located and would be capable of developing a much larger yield than that needed for the individual water requirements of either of these subareas. Therefore, it must be considered as a possible single source in serving virtually the entire Pope Valley service area as well as an alternative to James Creek or Goodings Reservoir. The largest size of resejTVoir studied would produce an estimated firm annual yield of edmost lU,000 acre-feet at an esti- mated unit cost of only $12 or $13 per acre-foot. It would inundate a total area of about 1*400 acres, of which only about 500 aci^s are ir- rigable. The estimated capital cost of this dam and reservoir, including a pumping plant capable of lifting the water to an elevation of 750 feet, U.S.G.S. datum, is about 2.25 million dollars. -223- It appears, therefore, that the Walter Springs dam and reser- voir is the most favorable project for supplying future water needs in Pope Valley. A privately developed reservoir on Upper Maowell Creek would be compatible with develojanent at the Walter Spidngs site. In ad- dition to a detailed design and cost study of the dam and resei^roir, a thorough study of the required distribution system costs, project bene- fits, suad availability of funds would be necessary to fully determine the economic justification smd financial feasibility of this project. Since the reservoir would be located in a position where it would inter- cept a large amount of the irrigation return flow, the reservoir yield would be increased but the quality of the water would be lessened. For this reason, a thorough study of the water quality aspects should precede final selection of a project for this area. DevelojHiient of additional, water supply projects in Pope Valley will depend, in large measure, upon the zeal of local residents in form- ing an active local agency for the purpose. Lake Berryessa and Capell Valley Service Areas These two potential service areas are discussed as a unit. Both covild be served by pvmiping fitjm Lake Berryessa. Two other sources for serving portions of these areas are Capell Creek and Adams Reservoirs. The magnitude of future water requirements for these areas has not been determined with any degree of certainty. It •vrais estimated that if lands in Capell VsLlley were piimarily devoted to irrigated agricul- ture, the total future requirement would be about 1,^400 acre-feet per year. However, in a recent water right application, the U. S. Bureau of -224- Reclamation, in behalf of Napa County, has filed for 7)500 acre-feet per annum for municipal and dcanestic purposes to be used within a gross area of about 40,000 acres bordering Lake Berryessa. It is believed that of this amount, about U,000 acre-feet were to be used in Capell Valley and 3,500 acre-feet along the westerly shore of Lake Berryessa. A siipplement to the application, states that "the point of diversion for quantities applied for shall be considered as Monticello Dam, although physical works, at the discretion of the Coionty of Napa, may be located on the bemks of the reservoir as the use of water may dictate as developed". Capell Creek Reservoir was studied as a possible alternative to pumping water directly from Lake Berryessa for use in Capell Valley. The estimated full annual inrigation requirement of 1,^00 acre-feet in Capell Valley could be developed at this site for an estimated $l6 per acre-foot. Estimates wei-e not made of the cost of pumping and conveying water from Lake Berryessa. However, cost of pumping water from Berry- essa to the Capell Valley area would be substantial because the static pump lift would range from about 36O to 6OO feet depending on the level of the lake. In selecting a source of additional water supply further consideration should be given to both alternative sources. Adams Reservoir was studied as a possible alternative to pvmip- Ing water directly from Lake Berryessa for use around the upper end of the lake where about 2,000 acre-feet of the previously mentioned annual requirement of 3,500 acre-feet would be needed. Of the plans studied, this reservoir was estimated to be capable of developing the least costly -225- water in the basin. A safe annual yield of 3»500 acre-feet was estimated to cost about $5 per acre-foot at the dam. However, the cost of the re- quired distribution system probably would be of considerable magnitude. Estimates of cost of pumping water from Lake Berryessa to serve this area were not made. However, according to the U. S. Bureau of Rec- lamation's operations studies of Monticello Reservoir, the water surface of the lake, during a prolonged period of drought, can be expected to fluctuate from a maxlmtmi elevation of kkO feet to a mininium elevation of 253 feet, U.S.G.S. datum. Pumping during low water stages would pose problems of considerable magnitude. The location of Adams Reservoir would be advantageous in serving areas around the upper end of Lake Berryessa, where the lateral distance involved in the fluctuation of the water sTirface of the lake would be at a maaimvmi. A detailed cost study of these two alternatives should be made before selecting a plan for securing additional water supply for the area. The cost of the required distribution system may well be the de- ciding factor. -226- CHAPTER VT. POSSIBILmES FOR FimNCING WATER DEVELOPMENT PROJECTS The extent and rate of water development in the Upper Putah Creek Basin will be controlled by the ability to secure financing for water development projects. In order to determine the sovirces of funds available to finance a water develoiment project, it is necessary to have a specific construction proposal for the lending agency to consider. All lending agencies limit the degree of risk they are willing to assume and the purposes for which they will lend money. The test of financial feasibility is, in essence, an examination of the willingness and ability of the borrower to rejwty the costs. While such an examination is beyond the scope of this bulletin, an appraisal of some of the potential sources of finsmcing is appropirLate . The iwtential sources of money are private, state, and federal; some projects may involve all three. Private Financing The type and extent of private financing appropriate to any specific project depends upon the scale and nature of the project. For exasiple, in some cases, individual wells ceui be financed directly by the owner without recourse to any lending agency, while it is very seldom that larger scale projects such as dams and reservoirs can be financed by this means. In the case of projects constructed by organized water districts and cities, capital expenditure programs for water resource development of relatively small magnitude are often financed thix>ugh cxirrent taxes and water sales. However, larger scale development pro- grams, in nearly all instamces, are financed by the issuance and sale of either general obligation or revenue bonds. General obligation bonds -227- are backed by the full faith and credit of the issuing agency. Repayment is guaranteed by the revenue from the project, plus the taxing power and all sources of revenue of the issviing agency; whereas revenue bonds are repaid by revenues from the specific project for which the bonds were issued. Bonding Capacity In general, agencies that would have a direct and overlapping debt, including the cost of the project, of less than about 25 percent of their assessed valuation, can expect to sell bonds at a reasonable interest rate. When outstanding indebtedness exceeds 25 percent, inter- est rates tend to rise. If the indebtedness becomes great enough the bonds become unsalable. In general, revenue bonds may Involve a higher risk and may be expected to bear somewhat higher interest rates than general obligation bonds. The bonding capacity for most areas in the Upper Putah Creek Basin will be limited because their assessed valuations are relatively low. State Financial Assistance State finamcial assistance to local water development projects may be available vmder the Davls-Grunsky Act in the form of loans or grants or both. Under certain circimistances, the State may participate directly in the project. State Participation The State may participate in the construction of a project if it appears desirable in the public interest to construct a larger project -228- than req\iired to supply the needs of the local agency proposing develop- ment. Such might be the case where an agency proposes to build a small dam and reservoir at the only site veil suited for a larger structure to sei^e additional potential water users, euid where construction of the larger project would be mutually beneficial to all parties concerned. In such a situation, the State may take part in planning, designing, constructing, operating, and maintaining the project, and may finance those costs of the project in excess of the cost necessary to meet the requirements of the agency planning the smaller structure. Legislative authorization and specific appropriation of funds are required for State participation. Loans The Department of Water Resources, with the prior approval of the California Water Commission, may lend up to h.O million dollars for any one project. The project must be primarily for domestic, municipal, agri- cultural, or industrial purposes, and the loan is limited to that portion of the project that cannot be finainced from other sources on reasonable terms. Loans may be made in excess of 4.0 million dollars for projects authorized by the Legislature. The loans bear interest at the same rate as the net interest cost on the last sale of State general obligation bonds prior to the filing of the loan application. However, if the State rate is not a multiple of one-q\iarter of one percent, the rate to be charged would be the next even one-quarter percent above the State rate. On this basis, interest rates on loans during I96O-6I would have approximated h percent per annum. The principal and interest of these -229- loans ntust be repaid vithin a maximum period of 50 years. When justi- fied, a delay in payment on the principal of such loans may be authorized to allow for a period of development not exceeding 10 years. During the 196I Legislative session, the Davis-Grunsky Act was amended to provide financial assistance to public agencies for the pre- paration of feasibility reports on proposed water development projects which had obtained preliminary determination of eligibility from the Department of Water Resources. Loans for feasibility reports may be made vtp to $25,000 provided funds cannot be obtained from other sooirces on reasonable terms. Such loans, with interest, must be rejjaid within 10 years, even if the project is found to be infeasible. After feasibility has been determined and the application is approved, the cost of preparing the detailed construction designs and specifications can also be covered by the loan for the project. Grants Grants may be made for that portion of the cost of a dam and reservoir properly allocated to recreational functions of statewide in- terest, or to the enhancement of fish and wildlife resources. These functions must be incidental to the primary purposes of the project but caimot be the primary purpose. Up to $300,000 may be obtadned through the Dei)artment of Water Resources, with the approval of the California Water Commission. Larger grants require authorization by the Legisla- ture. These grants are limited to costs allocated to the dam and reser- voir. No grant is authorized if the project does not include a dam and -230- reservoir. The cost of the onshore recreational facilities required for recreational development may not be covered by the grant. Federal Programs Various forms of federal finsuacing are available for local water development project assistajice. The most significant forms include the Small Reclamation Project Act (Public Law 98^) > the Watershed Protection and Flood Prevention Act (Public Law 566), and Public Facility Loans (Public Law 3^+5)' In the first two acts, provisions are made for non- reimbursable federal contributions for multiple -purpose projects involving flood control and wildlife enhancement. Small Reclamation Project Act Public Law 98^ (8i+th Congress) provides assistance to small irrigation projects. This law authorizes the Secretary of the Interior, through the Bureau of Reclamation, to lend a maximum of 5*0 million dollars on a project that does not exceed 10.0 million dollars. The act also authorizes grants up to 5*0 million dollars for flood control, and fish and wildlife enhancement where benefits to the general public welfare can be substantiated. However, the combination of loan and grant may not exceed the 5*0 million dollar maxi mum for any single project. Grants may be authorized even though no loan is requested, pro- vided irrigation is the primary project prupose, and the cost of the irrigation project will be borne by the locsil interests applying for the grant. The irrigation project may provide a domestic, industrial or miinicipal water supply, as well as commercial power, provided these functions are incidental to the irrigation project. -231- That portion of the loan properly allocated to irrigation of lands is interest-free except for single ownerships in excess of l60 acres (320 acres for a man and wife under community property laws). In- terest must be charged on the reimbvirsable portion of the project costs chargeable to providing irrigation benefits to lands in excess of l60 acres in a single ownership. Interest must also be charged on the por- tion of project costs allocated to commercial power, domestic, industrial, gmd municipal water uses. The interest rate charged on these loans is based on the May market bid quotations on the long-tem obligations of the United States Treasury bonds. This rate woxild apply to all contracts executed during the following fiscal year. The repayment period will be determined by local economic con- ditions and must be for the shortest practicable time, but may not exceed 50 years. Local interests must provide the necessary easements ajid all costs of lands, and guarantee that it has or cem acquire the necessary water rights. Water rights Involved in a legal controversy will prohibit the Secretary of the Interior's approval of the loan. The law further specifies that for projects costing less thsm 5.0 million dollars the local interests must provide, from sources other than the federal loan, a part of the project construction costs up to, but not to exceed, 25 percent of the reimbursable costs of the project. For projects costing over 5.O million dollars, the local interests must pay all of the costs over 5.O million dollars, and must make the contribu- tion that they would have had to make if the project cost had been 5.O million dollars. Local interests are responsible for plannixig, bviilding, -232- operating, and maintaining the system. The Bxireau of Reclamation may be consulted to examine the plans and inspect the construction, to determine if the project conforms to bureau standards. Watershed Protection and Flood Prevention Act Public Law 566, enacted by the 83rd Congress, as amended by Public Law 1018, authorizes the United States Secretary of Agriculture, through the Soil Conservation Service, to cooperate with local agencies in the planning and constructing of works for improving, protecting, and developing the land and water resources of small upstream watershed areas or subwatershed areas. These works can be for conservation, utilization, and/or disposal of water. Loans are confined to those areas approved by the Soil Conser- vation Service for watershed planning. The watershed must not provide a storage capacity of more than 5,000 acre-feet for flood water detention, or have a maximim storage capacity of more than 25,000 acre-feet. The maximum loan authorized by Public Law 566 is 5.0 million dollars. The interest rate is governed by the average rate paid on the outstanding long-term marketable securities of the United States Treasviry. The rate anno\mced at the beginning of the fiscal year will prevail throughout that fiscal year. Loans are scheduled for repayment within the shortest practicable time but may not exceed 50 years. The repayment period begins when the principal benefits begin to accnie to the project. Eligibility requirements set forth by the Secretary of Agri- cvilture specify that the local interests must be legally empowered to -233- install, maintain, and operate the works of improvements; have insuffi- cient funds suid be \inable to borrow the funds from a private source at a reasonable interest rate; be able to pay for the loan; have the legal capacity for obtaining, giving security and raising revenues for repay- ment of the loan; and sponsor, co-sponsor, or agree to participate in a watershed work plgm as set up by the Soil Conservation Service. Public Facility Loans As authorized under Public Law 3^5 f Bkth Congress, the United States Housing and Home Finance Administrator may purchase securities or make loans to public agencies to finance a project essential to public health and welfare where credit is not otherwise available on reasonable terms. PrioirLty is given to applications of communities of less than 10,000 inhabitants for construction of basic public works for mxmicipal purposes. Interest is determined by the Secretary of the Treasiuy, teik- ing into consideration the current rate of interest of comparable federal obligations. Types of Organizations The following discussion pertaining to various types of public districts empowered to deal with matters concerning water — its develop- ment, control, and distribution — is intended to point out the importance of selecting the type of organization best siiited to the desired purpose. It is not intended to be a complete treatment of this highly complex subject. In any specific case, those interested in forming a water district shovild consult an attorney who is familiar with the various water districts acts of California. -23^- I Existing Agencies At present, there are two agencies which encompass the entire Upper Putah Creek Basin and which are legally capable of dealing with most water problems of the area. These are the Lake County Flood Control and Water Conservation District and the Napa Coxrnty Flood Control and Water Conservation District. Both are county-wide agencies. The purposes and jxjwers of these two agencies are quite similar. Each can provide for control of flood and storm waters of their districts and for conservation of such water for beneficial purposes. In addition, the Napa County District's powers extend to outside watersheds suid water- covtrses flowing into their district. The districts are governed by their respective Boards of Supervisors; however, the Lake Coiinty DistirLct may delegate its powers to a commission of nine members. Separate zones may be established for specific projects euid/or bonding p\irposes. However, if a proposed zone of the Lake County District is to include land within a city, then the city must concur in establish- ing the zone. A provision in the lake County District's charter permits any chartered or incorporated city to withdraw from the district upon majority vote. Both districts claim specific powers of eminent domain to establish water projects necessary to achieve their respective purposes. Cooperation with federal agencies is also authorized. Projects are initiated by investigation of and reports on the zones considered, and through adoption by the respective Boards of Super- visors. The Board of Supervisors of the Napa County District may not proceed with a given action if protests are received from a majority of -235- the registered voters residing within the affected zones. The Napa Coxonty Board of Supervisors must suspend action on emy project in which holders of real property owning one-half or more of the assessed valuation protest the project. Financing is through general obligation bonds, subject to the approval of two- thirds of the voters within the zone affected. The bond- ed indebtedness is confined to the area approving the debt and does not become sin obligation of the taxpayers outside the district. Sources of revenue may include the sale of surplus water outside the districts as well as the sales and leases of property. Provisions are also made for an annual ad valorem assessment upon all property in zones for works benefiting such zones or to pay bonded indebtedness as it becomes due. In addition to these two coiaity-wide districts, there are two active and two inactive smaller organizations which are legally capable of dealing with development and /or distribution of water in the Lake Covmty portion of the basin. The active orgeuiizations are the Middletown County Water District (formed January 2, 1959) and the Middletown Soil Conservation District. The inactive agencies are the Lake County Water District auid the Middletown County Waterworks District No. 5. There are also several small private water ccanpajiies throughout the basin, but these probably would not be capable of developing water on a large scale. The Middletown County Water District boundaries encompass about 56 percent of the irrigable area in Collayomi and Long Valleys. Of the districts discussed, it has the most extensive purposes and powers. In addition to flood control auid water conservation, this district may de- velop and sell jxjwer, provide recreation facilities, and drain and reclaim -236- lands. Financing may be through general obligation bonds, revenue bonds, and/or 5-year interest bearing warrants. Revenues are from operation of works for any beneficial purpose, sales and leases of property, and, if insufficient to meet commitments, from ad valorem assessments or from a "water tax". New Agencies Needed for Water Development In view of the agencies already existing in the Upper Putah Creek Basin, it appears that prospective water users already have avail- able adequate and capable agencies to initiate the development of water resources and. to administer its distribution. The potential service ai*ea8 such as Collayomi, Long, Coyote, Pope, and Capell Valleys could be zoned for water development and receive water throiigh the Lake and Napa Counties Flood Control and Water Conservation Districts, or establish their own water district, whichever proved to be in their best interest. The Mid- dletown County Water District covers about three-quarters of Collayomi Valley and about one-third of Long Valley, and presumably is capable of developing and serving water in these areas. The remaining area in these two valleys probably could be annexed to this district and thereby could peurticipate in and benefit from water develoi)ed by this district. The extent to which new agencies are needed must be determined by ascertaining the existing eigencies' s\iitability to deal with local water problems and local preference for the method or methods of solving water problems. A major advantage of establishing a county water dis- trict rather than a flood control and water conservation district is the wider choice of bonding permitted. The former agency may issue general -237- obligation bonds, revenue bonds, and/or 5-year interest bearing warrants, whereas the latter agency is restricted to general obligation bonds. In cases where it is desired to include recreation facilities as part of a reservoir development it would be necessary to select a district having specific purposes smd powers to provide recreation rather than to form a zone within the Flood Control and Water Conservation Districts. Four such types of districts which have authority to provide recreation as a part of water development works are Conm\mity Service Districts, Coxmty Water Districts, Municipal. Water Districts, and Water Conservation Districts. A special district could be created by the Legislature which might add specific powers to those formed vmder the general act creating the various kinds of districts. Local Interest in Water Development Since the U. S. Bureau of Reclamation began construction of Monticello Reservoir in August 1953» there has been an increasing inter- est in water development in the Upper PutaJi Creek Basin. This interest received added impetus on February 7, 1957 > when the State Water Rights Board issued Decision No. 869 regarding the Bureau applications to appro- priate unappropriated water from Putah Creek for the Solano Project. In effect, this decision limits the annual amount of future appropriations of water in the upper basin to 33,000 acre -feet and stipulates that future development must be prior to full beneficial use of Monticello Reservoir water in the Solano Project service area. This increased interest in water development is evidenced in several ways. It was shown in Chapter II that the demand for water in -238- the upper basin has increased by an average of about 6 percent per year durtng the 6-year period 195*4-1960. This increased demand for water has been accompanied by increased activity in both ground water and surface water development. Numerous water wells -- some successful, some unsuc- cessful -- have been drilled. Private interests recently enlarged the storage capacity of McCreary Lake to augment the water supply available in the Bucksnort Creek area. Substantial inci^ases in the number of ap- plications to appropriate an increased amount of vmapproprlated water have taken place. Permits to store appropriated water in the upper basin issued by the State Water Rights Board since February 7, 1957 » total in excess of 7,700 acre-feet, whereas the combined storage permits and li- censes prior to that date total only about 5>100 acre-feet. In addition, applications since February 7 , 1957, to store appropriated water, which are presently pending or incomplete, total an additional l4,000 acre-feet. Increases in water needs, surface stoi^ge, well drilling activ- ities, and the flood of water right applications are not the only indi- cations of interest in water development. Both the Lake euid Napa Coxmty Boards of Supervisors have repeatedly indicated their interest in future water development in the Upper Putah Creek Basin. It was largely through their efforts that this reconnaissance investigation by the dejjartment was undertaken. The Lake County Board of Supervisors has shown specific inter- est in development of a reservoir on Dry Creek near Middletown. In 1958 they entered into an agreement with the engineering firm of George S. Nolte to determine the reasonableness of preparing a complete feasibility report -239- in accordance with the requirements of the Small Reclamation Project Act (P.L. S^h) . At about the same time they entered Into an agreement with the U. S. Bureau of Reclamation to conduct a land classification smd land use survey in connection with the proposed Dry Creek Reservoir and iriri- gation system. A conclusion of the Nolte stvidy was that such a proj- ect wo\ild be economically feasible. Local Interests have deferred action on this project awaiting the results of this reconnaissance investigation to see if alternative projects might be more advantageous. Lake County has continued to show active interest. In a letter from the Lake Covinty Flood Control and Water Conservation District to the department dated June 23, 1961, the District indicated that, in cooperation with the Mid- dletown County Water District, plans are being made to go ahead with a dam and reservoir on Dry Creek, and that, under the terms of their water right permit, the project must be vmder construction by December 1, 1961. Napa County's primary interests in futvire water development are presently centered in Pope and Capell Valleys suid along the westerly shore of Lake Berryessa. In Pope VauLley numerous small, individually built res- ervoirs and farm ponds have been constnicted in recent years. There have been several attempts to develop ground water supplies -- mostly \msuces- ful. These somewhat uncoordinated efforts provide an insignificant amoimt of water in comparison to the total future requirements of the area. Re- cently, private interests have been considering construction of a 2,000 acre-foot reservoir on Upper Maxwell Ci*eek, but progress on this project has been slowed because of extensive water right hearings in November, i960. 4 \ -240- In Capell Valley, several individual attempts to develop groiind water have resulted in obtaining limited supplies sufficient only for present domestic and stock watering needs. The only significant sxirface storage development in this valley is Moskowite Dam and Reservoir, com- pleted in 1951- In recognition of the possibility that both Capell Valley and the area along the westerly shore of Lake Berryessa could develop as residential and commercial areas, the U. S. Bureau of Reclamation, in be- half of the Napa Coiinty Boai-d of Supervisors, has applied for water rights in the amount of 7^500 acre-feet per annum, most of which woiild be pianped directly from the lake. All of these actions in the Upper Putah Creek Basin indicate a keen interest in water development. -2U- CHAPTER VII. CONCLUSIONS AND RECOMMENDATIONS As a resiilt of this reconnaissance investigation the following conclusions, and recommendations are made. Conclusions 1. Present water problems in the Upper Putah Creek Basin involve physical, econcanlc and legal factors. However, the foremost problem concerning water development confronting the people of the area is that of time available to appropriate and develop additional water supplies for future needs of the area. 2. Future development of loceil water resources could be inhibited by the inability to secure appropriative water rights to surface waters. On February 7, 1957, in Decisiion No. 869 the State Water Rights Board ordered that: "The permits and all rights acquired or to be acquired there- under are and shall remain subject to depletions of stream flow above Monticello Reservoir not to exceed 33,000 acre -feet of water annually, by future appropriations of water for reasonable beneficial use within the watershed of Putah Creek above said reservoir; provided such future appropriations shall be initiated and consum- mated pursuant to law prior to full beneficial use of water within the project service area under these permits." 3- The entire seife annual yield from Monticello Reservoir may be used by I98O, and all but 33,000 acre-feet of this yield may be put to use by 197^. Thiis, there remains only 13 to I9 years for the local people of the upper basin to appropriate, develop, and put to use, local water supplies. ^4^. Limitations imposed by the permits granted under Water Rights Board Decision No. 869 would not apply to lands with rights to pumped ground water applied to beneficial use on lands overlying a ground water basin, or to stream flow depletion caused by natural recharge of -243- the basin. On the other hand, it is believed that the limitations would apply to extracted ground water used on lamds not overlying a ground water basin suid to the recharging of the basin by artificieil means. 5. Of the 8,100 acres of land presently devoted to crop land in the basin, only 2,600 acres are irrigated. This is a relatively minor degree of development ccsapared to the potential develojanent of more than 28,000 acres of irrigable land. 6. The estimated present mean annual water requirement in the basin is about 8,500 acre-feet, of which, over 95 percent is for irrigated agriculture. The basin experiences a natural water supply deficiency during fall and summer months, but the magnitude and extent of this deficiency in relation to the present water requirement is not known. 7. Irrigation will continue as the dominant water requirement in the basin within the foreseeable future. 8. Payment capacity for agricultural water on representative crops in the basin ranges from about $3 to $6 per acre-foot for irrigated pasture and alfalfa, respectively, to about $20 per acre-foot for decidu- ous orchard crops, to a high of about $33 per acre-foot for vineyard crops . 9. Future irrigated agriculture of appreciable magnitude will probably be restricted to deciduous orchard aind vineyard crops because of the relatively high cost of the potential major water development works in relation to payment capacity tor agricultural water. 10. Future residential, commercial, and recreational develop- ments may be induced along the westerly shore of Lake Berryessa and in Capell Valley by the year-round recreational opportunity afforded by the -2kh. I If lake and by its close proximity to Sacramento and the San Frauicisco Baiy Area. These lands could physically support an estimated population of about 60,000 people. Whether or not these lands will ever be developed to their fullest capabilities is not known at this time. I 11. The future sixpplemental water reqxiirement for full development of the presently undeveloped irrigable lands in the selected service areas (which represent 75 percent of the irrigable lands in the basin) is esti- mated to be about 30,000 acre-feet per year. 12. In cases where residential, commercial, and recreational developments encroach on the irrigable lands in the basin, the water requirement estimated for irrigation should be more than ample. Developments of this type occurring on nonirrigable lands, such as that taking place along the westerly shore of Lake Berryessa, will have water requirements over and above those for irrigation. A thorough appraisal of the rate and magnitude of future demands for water for these types of development was not made during this recoxmaissance investigation. 13. Runoff in the Upper Putah Creek Basin is derived princi- pally from rainfall. The estimated mean annual natureO. runoff originating in the basin is about 3^,000 acre-feet, which greatly exceeds gll possible future beneficial uses which may reasonably be anticipated in the basin. Ik. Runoff is presently developed to a very high degree but only a small amount is available for local use. The present average annual depletion of runoff resulting from use above Monticello Reservoir is about 6,000 acre-feet, while the net safe annual yield from Monticello Reservoir, including release for downstream prior rights, is about 262,000 acre-feet — all to be used outside the upper basin. -245- 15. Surface water supplies within the Upper Putah Creek Basin are generally of good mineral quality except for excessive hsj-dness which may ajmoy domestic iisers. Another possible exception occurs in localized areas when high boron concentrations during low flows make the water lonsuitable for irrigation on all except the most toleremt crops. Surface storage reservoirs would tend to reduce these problems by mixing and dilu- tion of the more mineralized low flows with the better quality rainfall- fed high flows. Although water quality data on groixnd water supplies are sparse, it is probable that its mineral character closely resembles that of surface water. 16. The prospects for developing additional ground water in significant quantities throughout the major portion of the watershed are not favorable. There may be exceptions to this probability in Collayomi, Long, and Coyote Valleys, where a substantial portion of the present agricultural water reqiiirements are met from existing wells. 17. Additional water supplies probably could be developed in the Upper Putah Creek Basin, in varying magnitudes at attendant costs but within the range of payment capacities of vineyard and orchard crops, through larplementation of any one or a ccanbination of the following plans. a. Utilization of ground water could be increased in Collayomi, Long, and Coyote Valleys. b. Dams and reservoirs could be constructed at Dry Creek, Middletown, Putah Creek Canyon, Coyote Creek, James Creek, Walter Springs, Goodings, Capell Creek, or Adams sites. -246- c. Yield of the Dry Creek and James Creek reservoirs could be augmented by constnaction of facilities for stream flow diversion from St. Helena and Swart z Creeks, respec- tively. Construction of these facilities would reduce the unit cost of water delivered frcxn Dry Creek and James Creek reservoirs. Construction of Coyote Creek reservoir would require a diversion frcau Big Canyon Creek because of the limited runoff at the Coyote Creek site. d. Yield of the Middletown or Putah Creek Canyon reservoirs could be augmented by construction of an off -stream storage reservoir at the Crazy Creek site. This does not appear to be necessary in view of other possibilities available. 18. The least costly method of developing additional water sup- plies probably would be through increased utilization of ground water where possible. Present ground water pumpage could possibly be doubled in the Collayomi-Long Valleys and tripled in Coyote Valley. Reliable estimates of the amount and cost of additional ground water which might be developed could not be made during this reconnaissance investigation. Limited data indicate that the yield of wells in these basins is highly variable. Pre- ; diction of the total number of wells necessary to meet the needs for sup- iplemental water was impossible because of the limited data available. Nor could 6uiy prediction be made of the nvunber of test holes which might have to be drilled in any particvilar area in order to provide a single satisfactory I well . -2k7- 19. The most promising source of an additional surface water supply for the Collayomi-Long Valleys service area appears to be Dry Creek Reservoir, with an augmented supply from a St. Helena Creek diversion works. Reconnaissance studies indicate that combined firm annual yields rajaging frcan about 8,000 to 11,000 acre-feet could be obtained from these facilities for about $l6 per acre-foot. Capital costs for these facilities would range from about 2.k million dollars to about 3.5 million dollars, depending upon the yield desired. This project could be stsiged, to a limited extent, by deferring construction of the St. Helena diversion works. Under this concept, initial capital costs could be reduced by about O.i)- million dollars but the initiaLl xanit cost of water would be increased by about $2 per acre-foot. These yields and costs were based on a single pxirpose project. In addition to water conservation. Dry Creek Reservoir has con- siderable potential for outdoor recreation and might be planned to provide sOTie flood protection for the community of Middletown. Constructing the reservoir to a somewhat larger capacity, to provide a moderate amount of storage at minimum pool for recreation, would also give added assurance of an adequate water sirpply during periods cf severe drought. The Dry Creek Project might be operated conjunctively with ground water storage, so as to reduce the size and cost of the required surface reservoir and the cost of an extensive distribution system. Future feasibility studies of the Dry Creek Project should in- clude all of these factors, with the objective of providing the greatest benefits to the greatest n\miber of people in the Collayomi-Long Valleys service area, including the coomiunity of Middletown. Such multiple purpose use shoiild result in a lower unit cost of water. -2l»8- 20. Middletown Reservoir and Coyote Creek Reservoir, with a diversion from Big Canyon Creek, appear to be competitive sources of addi- tional siirface water supply for the Coyote Valley service area. Recon- naisssince estimates indicate that a firm annual yield of approximately U,000 to 5,U00 acre-feet could be obtained from either of these two projects for $8 to $9 per acre-foot. Capital costs for either of these two projects would range from about 0.6 million dollars to 0.9 million dollars depending on the yield desired. Coirfiarable yields from Putah Creek Canyon Reservoir would be more costly thsji from either of these two reservoirs. Because Coyote Creek Reservoir has a greater potential for out- door recreation than Middletown Reservoir it may prove to be the more desirable project of the two. However, the possibility of increased ground water development in Coyote VsLLley may make possible the coordinate and conjunctive operation of either of these reservoirs with ground water storage. Such operation would reduce the size and cost of the required surface reservoir sind the cost of an extensive distribution system. Future feasibility studies of potential water supply develop- ments for the Coyote Valley service area should include a more detailed appraiseLL of all of the pertinent factors. Putah Creek Canyon Reservoir and off-streeim storeige reservoir on Crazy Creek should be eliminated from further consideration. 21. In the Bucksnort Creek area, the estimated firm annual yield of the presently developed water supply from Detert and McCreary Reser- voirs is capable of meet iig the estimated present and future water require- ments of that area. Therefore, no additional facilities should be -2^9 . contemplated for that area. However, should the actiaal water requirement exceed the actual yield from these reservoirs, additional yield could be obtained at reasonable cost by enlarging either reservoir. 22. The most premising source of an additional water supply for full development of the Pope Valley service area appears to be Walter Springs Reservoir. Reconnaissance studies indicate that a firm annual yield of almost 1^1,000 acre-feet could be obtained from this reservoir and pumped to an elevation of 750 feet for about $12 or $13 per acre-foot. Capital cost for this project would be about 2.2 million dollars. Additional development of ground water in significant quantities is not likely in this area. Shoxild local interests desire to proceed initially with a smaller degree of development, Walter Springs Reservoir, Goodings Reservoir, and James Creek Reservoir, with a diversion from Swartz Creek, would all be competitive on a unit water cost basis. For a firm annual yield of about 6,000 acre-feet, water coiold be developed for about $15 to $l6 per acre-foot. Although unit cost of water from these smaller alternatives would be comparable, capital costs would be about 1.9 million dollars for the James Creek Project and only 1.1 million dollars or 1.2 million dollars for the Goodings or Walter Springs projects, respectively. This difference in capital cost woiild be offset by the average armiial costs because of required pimping costs at the Walter Springs or Goodings sites. Future feasibility studies of potential water supply develop- ments for the Pope Valley service area should include a statement from the local interests of the desired level of initial development, after -250- which more detailed studies of the appropriate alternatives should be made. Future studies of the Walter Springs Reservoir site should also include the possibilities for construction of a concrete arch dam about 1,CXX) feet downstream fnsm the site discussed herein. 23. Napa County is presently taking steps to meet ajiticipated future demands for domestic water along the westerly shore of Lake Berry- essa and in Capell Valley by secuiring water rights to pimip directly from the lake. IXiring prolonged periods of drought the water surface of the lake cam be expected to fluctuate through wide limits which would induce problems of considerable magnitude when pumping water during low water stages. Estimates of the cost of obtaining water from this source were not made during this reconnaissance investigation, but were made for two alternative sources. An estimated firm annual yield of 1,1+00 acre-feet for use in Capell Valley could be obtained from Capell Creek Reservoir for about $16 per acre -foot. Capiteil costs for this reservoir would be about O.5 million dollars. There are two problems connected 'Vfith pumping water from the upper end of Lake Berryessa; (l) the difficulty of designing an efficient pumping plant for the varying water elevations, and (2) the large lateral displacement which takes place for small vertical displacements. The location of Adams Reservoir site would therefore be advantageous in serving areas around the upper end of the leike. Future feasibility studies of potential water supply for these two areas should include a more detailed study of all of the foregoing factors. Studies of the i-equired distribution system along the lake shore -251- should also be made, since the cost of these facilities may well be the deciding factor in selecting a plan to serve this area. 2k. In view of the agencies already existing in the Upper Putah Creek Basin, it appears that prospective water users already have avail- able adequate and capable agencies to initiate the development of water resources and to administer its distribution. However, in order to secure a wider choice of possibilities for finaincing water development projects or to be able to include recreation as a part of a potential project, certain areas may find it advantageous to form new districts having more extensive powers. 25. There appears to be a keen local interest In future water developnent throughout the Upper Putah Creek Basin. However, additional information is needed on current views of local Interests. This informa- tion will be needed before a specific project can be formulated. 26. All possible projects considered in the Upper Putah Creek Basin would be compatible with The California Water Pleui and would not preclude water developments in other areas of the watershed. -252- I' Reconmendatlons As a result of this reconnaissance investigation of the engi- neering, geologic, economic, and legal aspects euffecting future water de- velopment in the Upper Putah Creek Basin, the foJJLowlng recommendations are made: 1. That, after receiving documented and specific desires of local interests, a more detailed investigation be conducted to determine the economic justification and financial feasibility of specific projects in the upper basin, including the maximum practical extent of further de- velopment of ground water occurring in Collayomi, Long, and Coyote Valleys. 2. That a program to collect additional basic hydrologic data at specific locations be initiated immediately to provide a sound basis for more detailed analysis of the more favorable water development possi- bilities. In particvilar, stream geiging stations should be installed on streams planned for diversion to off-stream storage reservoirs. A com- prehensive groxmd water level measurement and stream flow percolation determination program in areas deemed suscepitble to additional ground water development should be vuadertaken. 3. That local interests proceed with development of their water resources as fast as economically possible in order to keep the possibil- ity of loss of right to appropriate presently unappropriated water at a minimum. k. That local interests continue to appear, and state their interest and present position, at all hearings on water rights affecting the Uprper Putah Creek Basin. -253- 5. That plans for further development of the water resources of the Upper Putah Greek Basin be based on the conclusions and recommenda- tions of this investigation and that no further consideration be given to those sites eliminated by these studies. ■251.- APPENDIX A SUMMARY OF APPLICATIONS TO APPROPRIATE WATER IN THE UPPER PlfTAH CREEK BASIN I a: Ul 1- < 5 z iij to H < ID < CD Ol (£ ^ _r Q. O Ul LU or a: Ul cr u CD Q. S a. I UJ < < 1- (- Q. o Z) Ul H Q. (0 cr Ul u o z a. o 0. VJ 3 < K < 2 o -1 a. a. < 8 ij s 2 3 u <-■ o s 1 I tz 3 3 3 U Q U M Q M « I 3 •H 3 3^ § n 5 t E o t: o & s T) vO £ ^ ^ rr\ C\ 4J VO -4 a CTv CM ftj OJ 8 S S 8 3 3 3 3 V^ Vi CO a (0 (S CD Vi v* if\ l/N i^ r- ft8 ^:1 O o 0\ rH 8 o rH o o o o & o u fi « I ? a 3 9 8 3 3 I S 3 3 8 8 8 S V 1 a V o 8 a £ 3 3 $ 4-> 3) 1 8 g 8 c o H <> 'Tl u •H ■H u 4^ ■H ■P +* ■rt ■p a 3> ^ £ % tJ 8. 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"•^ ^f? +j m o to to e 03 ^ (^ s s UA LPs CT\ s ^ '^ •<; 0) Q) Jh u O QD j:: r; 01 ■H iJ U> VD vo s g a § OS c g^ 5 5 ^5 u ol u d u St P^ •H 0) v> s ■H Jd +J +> Jh +J CJ -O w x: DO O (0 CJ tn o q a> cQ u at a K S -H S (C B CO P [L, O 4> Q rH t4 ^ ^. C 3 C •^ c ^ oj a> ■* eo OJ ^ O -P O c o C -H +J C -H +^ C -H r-t ■H O -H o u ^ 5ig o -P :3 4J H +J ■H a) CJ o 4J al +J M J4 +J 0) ^ +J 0) 01 0) lU «} 3 CJ aJ 3 CJ 05 ^. X! ■p Si u S-S o DO'S O bO CJ CO o •H a -H C -P ■H c +J •H flJ -H Ih h 4; ^1 M W Jh M C/i Jh CC [i, a w "in m (0 tM 0} cd oi ol "m Cm CJ •;h tn < OJ ^0) 0) a u W >i 4J O OJ 0) T( Ih X] OJ OJ O 0] to rH 3 o OJ p OJ -a cd a o g" :: ?, R OJ cy cT^ OJ gse5 i g i ■p 3 J3 ^ & U 5 5 +J 3 J3 §§ 3 1 -H 0) 0) ^ •H Jri OJ ^ P ^ ^ OJ ti Of ]-. 0) ■P -P OJ P £ +J Q> j<: tn to t. t, 0) o J (0 c O I JiS D Ou I CJ IS ~ ^ -^ ^^ to ol a bu OJ £ ^ ^ 5 S3 S CD A-6 APPENDIX B BIBLIOGRAPHY II BIBLIOGRAPHY 1. Averitt, P. "Quicksilver Deposits of the Knoxvllle District". California Journal of Mines and Geology. Vol. kl, No. 2. April 1945. 2. Bailey, E. H., Yates, R. G., and Hilpert, L. S. "Quicksilver De- posits of the Mayacmas District". California Journal of Mines and Geology. Vol. 42, No. 3. July 191+6 . 3. Borglin, E. K. "Geology of Part of the Morgan Valley Quadrangle". University of California. Unpublished thesis. I9UB. h. Boyd, H. "Geology of the Capay Quadrangle". University of California. Unpublished thesis. 1955 • 5. Brice, J. C. "Geology of the Lower Lake Quadrangle". California Division of Mines. Bulletin I66. 1953. 6. California Department of Water Resources, Bulletin No. 56, "North- eastern Counties Investigation", June I96O. 7. - - - - Bulletin No. 90, "Clear Lake-Cache Creek Basin Investi- gation", March I96I. 8. California State Water Rights Board, "Report on Water Rights Appli- cations 11198, 11199, 12578, 12716, United States of America-Bureau of Reclamation". September 1956. 9. - - - - "Reporters Transcript for Water Rights Hearing on Appli- cations I8I+O5 and lQk67 by Usibelli Coal Mine, Inc." November 29, 196O. 10. California Office of Legislative Coiansel, California Water Code, "Davis-Grunsky Act", 1957, and Amendments through I96I. 11. Carter, W. H. "Geology of the Northeast Comer of the Calistoga Quadrangle". University of California. Unpublished thesis. I9I+8. 12. Conrey, B. L. , Jr. "Geology of the Northeast Comer of the Calistoga Quadrangle". University of California. Unpublished the- sis. 1958. 13. County Clerk, Lake County, California. "Index to Great Register of Lake County, California"... General Election, November 8, i960. B-1 ik. Ford, R. S., Nichols, H. G., Peters, J., Richie, R., et al. "Geology of a Strip Across the Northern Part of the Mt. Vaca Quad- rangle". University of California. Unpublished report. I9J48. 15. Gilluly, James, Waters, A. C, and Woodford, A. 0. "Principles of Geology". W. H. Freeman & Co. 1959, p. 398. 16. Lawton, J. E. "Geology of the North Half of the Morgan Valley Quad- rangle". University of California. Unpublished thesis. 195^. 17. Napa County Plajining Commission "LaJce Berryessa Land Use Plan". i960. 18. National Park Service "Public Use Plan-Monticello Reservoir (Ledce Berryessa), Solano Project, California". October 1959- 19- Nolte, George S., Consulting Civil Engineers. "Report on Dry Creek Dam and Iridgation System, LaJce Coimty Flood Control and Water Conservation District, Zone 2". 20. - - - - "Project Hydrology, Dry Creek-Mlddletown Project, Lake County, California". JuOy I96O. 21. Richter, C. F. "Seismic Regionalization". Seismological Society of America. Vol. 49, No. 2. 22. Taliferro, N. L. and others "Geology of the Mt. Vaca and Mt. Vaca NW Quadrangles". University of California. Unpublished map. 1951. 23. - - "Geology of the St. Helena Quadrangle". California Division of Mines. Unpublished map. 2k. United States Bureau of the Census "U. S. Census of Population, 1950 and i960. Number of Inhabitants, California". U. S. Government Printing Office, Washington, D. C. 25. United States Bureau of Reclamation "Appendix A to Yolo-Sclano Development of the Comprehensive Plan for Central Valley Basin, California Water Supply". May 19^7. 26. - - - - "Putah Creek Alternate Upstream Storage Plans, Yolo- Solano Development, Central Valley Project". March I9U9. 27. - - - - "Factual Report, Solano Irrigation District, Solano Coxmty Project, California". May 1950. B-2 28. - - - - "Technical Studies in Support of Factual Reports, Solano Irrigation District". May 1950. 29. - - - - "Solano Project Definite Plan Report". September 1953- 30. - - - - "Appendix A, Hydrology, to Solano Project Definite Plan Report". July 1953 • 31. - - - - "Solano Project, Solano County, Napa County, California". 1959. 32. United States Coast and Geodetic Survey "Earthquake History of the United States, Part II, Stronger Earthquakes of California and Nevada". Serial No. 609. 1950. 33. United States Department of Agriculture Bulletin 25^+ "Irrigation Resources of Ceilifomia euid their Utilization". Frank Adams, 1913. 31+. United States Geological Survey "Surface Water Supply of the United States, Part 11: Pacific Slope Basins in California". Water Supply Papers from I905 through 1959 • 35. - - - - "Compilation of Surface Water Records, Pacific Slope Basins, Central Valley, California". Water Supply Paper No. 1315-A. 1950. 36. University of California, Agricult\iral Extension Service, Lake Co\anty "Sample Costs for Walnuts, Irrigated Orchard also Non-Irri- gated Orchard". July 1955- 37. - - - - Napa County. "Farming in Napa Co\inty". July 1959* 38. Upson, J. E. and K\mkel, F. "Ground Water of the Lower Lake-Mlddle- town Area, Lake County, California". United States Geo- logical Survey. Water Supply Paper I297. 1955- 39. Weaver, C. E. "Geology and Mineral Deposits of an Area North of San Francisco Bay, California". California Ett vision of Mines. Bulletin IU9. 191+9. B-3 1 N 7 'A H / STATC or c DEPARTMENT OF WATER RESOURCES CHVISIOM or HCSOUIVCCS PLANNING UPPER PUTAH CREEK BASIN INVESTIGATION LOCATION OF UPPER PUTAH CREEK BASIN PLATE 2 LECEHD PRESENTLY DEVELOPED LANDS REQUIRING WATER SERVICE I URSAN Arc SUBURBAN LANDS RtCREATCNAL LANDS IRRIGATED ACRICULTUOAt. LANDS CLASSIFICATION OF POTENTIALLY IRRIGABLE LAND GROUPS VALLEY OR SLIGHTLY UWULATtNC LANDS WITH iOlLl COM^BIMMC «OtUM TO DEEP tFFICTtvf »00T ZWli U*0 itnTABLE FOR ALL CLIMATICALLY ADAPTED CROPS. VALLEY OR SLIGHTLY UM>ULATING LANDS WITH LIMITED CROP AOAPTAftlLITT DUE TO IKALLO* D(PTM 0» (FFeCTIvt ROOT ZONE OR TO PHESCNCE OP ROCK IN plO« ZONE GENTLY TO STEEPLY SLOPING AND ROLLING HILL LANDS ■ iTh SO'Ll COuPRIStNO MEDIUM TO DEEP EFFECTIVE ROOT ZONES SUITABLE FOR ALL CLIMATICALLT ADACTeo CROPS *H0 LIMITED ONL» BT EASE OF OEVELOPMEMT IMPOSED BT TOPOGRAPHIC CONDITIONS GENTLY TO STEEPLY SLOPING AfO ROLLING HILL LAfCS WITH LIMITED CROP ADAPTABILITT DUE TO SMALLO* DEPTH Of EFFECTIVE ROOT ZONE MCFRESSNCE of ROCK IN THE PLO* ZONE AND ALSO LIMITED BT EASE OF OEVELOPMEKT IMPOSED BV TOPOORAPKIC CONDITIONS. MIOOLETOWN COUNTY WATER DISTRICT BOUNDARY STATE or CALIFORNIA DEPARTMENT OF WATER RESOURCES DIVISION OF RESOURCES PLANNING UPPER PUTAH CREEK BASIN INVESTIGATION LAND USE AND CLASSIFICATION 1961 SCALt OF MILES /s UPPER PUTAH CREEK BASIN INVESTIGATION LAND USE AND CLASSIFICATION 1961 PLATE 3 KEY TO WELL NUMBERING SYSTEM c A E ' " IS o - L ' TION 56 11** ,;, " T9 N ' * oc * a M D B ftM WELLS SHOWN ORE NUMBEHEO SY TOWNSHIP, RANGE, AND SUBDIVISION OF SECTION e g TION /R5W -51 PI (TO f»CiLiT»TL WELL NUI*- URING.US L«iO SUWVE' SECTION LtNES WERE ItJtMOtO THROUOMOUT L»ND fi«*MT *«C*S I STATE OF CALirOHNIA DEPARTMENT OF WATER RESOURCES DIVISION OF RISOURCES PLANNING UPPER PUTAH CREEK BASIN INVESTIGATION LOCATIONS OF WELLS CANVASSED 1961 SCALE OF MILES EY TO WELL NUMBERiNG SYSTEM B t [*_•] I • - " ..■■ •f • UPPER PUTAH CREEK BASIN INVESTIGATION LOCATIONS OF WELLS CANVASSED 1961 I I PLATE 6-A ° Capacity limited by topogroptiy 4,0 42 44 46 48 5.0 "^ STATE OF CAUFOBNIA DEPARTMENT OF WATER RESOURCES UPPER PUTAH CREEK BASIN INVESTIGATION LOCATIONS OF DAM AND RESERVOIR SITES 1961 r^ PLATE 6-A ,^ ^ y ^ ■ = C( ipoclty linn ited by to pogrophy 4.0 4.2 4.4 4 6 4 8 5 COST COYOTE CREEK RESERVOIR - DRY CREEK RESERVOIR NOTE; -r- - Capocity limited by topography 2 4 0,6 6 18 2.0 2.2 2.4 2 6 2.B 3.0 3.2 CAPITAL COST OF DAMS AND RESERVOIRS, IN MILLIONS OF DOLLARS 3.6 3 8 4 4 2 4 4 4 6 4 8 5.0 RECONNAISSANCE ESTIMATES OF RELATIONSHIPS BETWEEN STORAGE CAPACITY AND CAPITAL COST FOR RESERVOIRS IN LAKE COUNTY DEPARTMENT OF WATER RESOURCES 1961 1 PLATE 6-B NOTE: 1 For storoge capo estimated capital c< 1 \ city of 50 >sl would b 1 000 ocre- e 2.1 miilioi 1 feet, 1 dollars. GOOOING S RESERV OIR / / /■« WA LTER SPf INGS RES ERVOIR ^ ^ ^ JAMES CF »EEK RES ERVOIR — >- '^ ^ ■^ • 20 2.2 2.4 2.6 2.8 30 3.2 34 36 38 RESERVOIRS, IN MILLIONS OF DOLLARS 5ETWEEN STORAGE CAPACITY AND CAPITAL COST IN NAPA COUNTY I 32 30 28 26 24 < i 20 i I z IB >-' O 3 ,6 1 cr O £ '" (E 12 g / note; 1 For Q storoge copocily of 50, estimated copitol cost would b 1 000 ocre- s 2.1 million eet, dollars. / / 1 GOODINGS RESERVOIR / AD IMS RESE RVOIR / / / / / /■< WALTER SPRINGS RES ERVOIR / / / / / / / / / / ^ / / e / / JAMES C ?EEK RES ERVOIR~ ^ / ^ / / ---• ^ ^ ^ / --' y -CAPELL CREEK f ESERVOIf X / 2 4 0.6 0.8 1.0 1 2 1.4 1.6 1.8 2.0 2 2 2.4 2.6 2,8 CAPITAL COST OF DAMS AND RESERVOIRS, IN MILLIONS OF DOLLARS 30 5.2 3 4 36 38 RECONNAISSANCE ESTIMATES OF RELATIONSHIPS BETWEEN STORAGE CAPACITY AND CAPITAL COST FOR RESERVOIRS IN NAPA COUNTY DEPARTMENT OF WATER RESOURCES 1961 I I I 4 PLATE 7-a I PLATE 7-A 15 14 13 12 P JTAH CREEK CANYON RESERV With oft-streom storage in Crazy Creek Reservoir /OIR f \^ M DDLETOW ilh off-slr< Crazy Cre N RESERV am storogc Bk Reserve OIR / / VI in — __, ^ ^ 1- " 1 1 DRY CREEK RESERVOIR y on Creek \/ ./ -^-^C RY CREE C RESERV 3IR A. ■^ _ o -1 / ' r y . y"^ . '^ 7 / / / _____ — COYOTE CREEK RESERVOIR // / ^ . - u- With 25 second-foot diversior from Big Conyon Creek ^--^/ V . ^ z 6 _i 4 ^;C / y^ / // >^ r Z z < (^ '/^ — MIDDL ETOWN RE SERVOIR / // PUTA H CREEK CAt4Y0N F ESERVOIR COYO TE CREEK -V y. ^/ /y y ^ // 2 DRY C REEK-^ ■z // y 5 6 7 8 9 10 II 12 GROSS RESERVOIR STORAGE CAPACITY. IN THOUSANDS OF ACRE -FEET 16 IT RECONNAISSANCE ESTIMATES OF RELATIONSHIPS BETWEEN ANNUAL YIELD AND STORAGE CAPACITY FOR RESERVOIRS IN LAKE COUNTY OEPARTMENT OF WATER RESOURCES 1961 PLATE 7-B / y Z' :/< ■ — WALTf :r sprinc S RESERV OIR i ! i ADA (Bas MS RESEF 9d on safe (VOIR yield) >- ^ ^=^ ""^ OIR 8 20 22 24 26 CAPACITY, IN THOUSANDS OF ACRE FEET 28 30 32 34 36 38 BETWEEN ANNUAL YIELD AND STORAGE CAPACITY DR NAPA COUNTY I 15 13 12 / / / / //"^ ^- WALTE .R SPRINC S RESERVOIR uj L 10 9 / < O jame; With 2 fr CREEK 5 second-f am Swartz RESERVOI oot diversio Creek ^ V / z < O // / / 1 ADAMS RESERVOIR (Bosed on safe yield) ^. , (- 8 / JS^ — ■ — z / / o / / ^^""""^"^ - 7 / / ^^ 3 a: / / ^ ^.''JAM RE ;S CREE SERVOIR ; --^ fTi 6 y^ -^^ z / ^^' -J / / ^r"^' z z < // ^ ^ r^^ CODINGS RESERV 31 R 4 3 2 / / / y y /^ f/ / / / / y^ -* / y^ ^~^CA >ELL CRE EK RESE WOIR / 14 16 IS 20 22 24 GROSS RESERVOIR STORAGE CAPACITY, IN THOUSANDS OF ACRE FEET 26 26 30 32 34 36 36 RECONNAISSANCE ESTIMATES OF RELATIONSHIPS BETWEEN ANNUAL YIELD AND STORAGE CAPACITY FOR RESERVOIRS IN NAPA COUNTY DEPARTMENT OF WATER RESOURCES 1961 I I PLATE 8-A I "I 12 13 [Cre of firm annual yield, in dollars fWEEN ANNUAL YIELD AND UNIT COST /LAKE COUNTY PLATE e-A 16 PUTAH CREEK CANYON RESERVOIR With off-stream storoge In —^^^ Crozy Creek Reservoir 1 1 13 12 DRY CREEK RESERVOIR With 25 second-foot diversion from St Helena Creek 1 > /• \ ^ / MIDDLETOWN RESERVOIR With off-stream storoge In — Crozy Creek Reservoir 1 1 / II ^ y 5 w < U. O i 9 < o o > 7 cc u. z 6 < Z Z ^ 5 4 3 2 \ ■ DRY CREEK RESERVOIR-^ 1 1 > y COYOTE CREEK RES With 100 second-foot from Big Canyon 1 ERVOIR diversion -, :reeli X V ^ \ / / /- \ \ / / COYOTE C With 25 se from B REEK RE cond-foot ) Canyon 3ERV0IR diversion ~ :reek -^ /• ^" \ J / \ \ \ i MtDDLETC WN RESE IVOIR^ A ( \ \ \ s. \ \ ^ PUTAH CR EEK CAN'T ON RESE WOIR— ' -^ \ ^ V ^ ^-~ .^^ --- t Base d on una located c osts as d iscussed n chapter E. *^ 7 e 9 10 II 12 13 AVERAGE ANNUAL COST PER ACRE -FOOT OF FIRM ANNUAL YIELD. IN DOLLARS 14 15 16 17 18 19 20 t RECONNAISSANCE ESTIMATES OF RELATIONSHIPS BETWEEN ANNUAL YIELD AND UNIT COST OF WATER FOR RESERVOIRS IN LAKE COUNTY DEPARTMENT OF WATER RESOURCES 1961 /^ PLATE 8-B >T OF FIRM ANNUAL YIELD, IN DOLLARS UPS BETWEEN ANNUAL YIELD AND UNIT COST F iIRS IN NAPA COUNTY 16 IS 14 13 12 II S 10 L. 9 o Z g 8 X z (E il 6 1- z J •I i = z < 3 2 « Includes U.S.G.S, with an Service Based o cost of pu datum, to Qlternativ Area. 1 unolloc mpinq To a make unit e gravity s ited costs n eievotio water cos upply for 05 discu n of 750 ts compar Pope Valle ssed in c eet, able \ 1 lopter 3C \ •^ WALTER SPRINGS RESERVOIR « \ \ JAMES CREEK RES With 25 second-fool from Swortz Creek ERVOIR^ \ diversion > ^ ^ v / / / \ / X GOOOINGS RESERVOIR * 1 t / / ^ \i /y ^ h -^ ADAMS R ( Bosed or ESERVOI sofe yield Fi ) \ V JAMES CREEK RESERVOIR- 1 1 / / \ ^ N,^ / 1 \ ^^ ^ ^ V, / s \ Nj ■^ / CAPE -L CREEK RESERV OIR^ ' — ^ n 7 8 9 10 II 12 13 14 AVERAGE ANNUAL COST PER ACRE-FOOT OF FI RM AN NUAL Yl ELO . I N DOLLARS 16 19 20 21 22 RECONNAISSANCE ESTIMATES OF RELATIONSHIPS BETWEEN ANNUAL YIELD AND UNIT COST OF WATER FOR RESERVOIRS IN NAPA COUNTY DEPARTMENT OF WATER RESOURCES 1961 THIS BOOK IS DUE ON THE lAST DATE STAMPED BELOW THIS BOOK IS DUE ON THE lAST DATE STAMPED BELOW BOOKS REQUESTED BY ANOTHER BORROWER ARE SUBJECT TO IMMEDIATE RECAL^ DECEIVED JAN ?1 1989^ PHYS SCI LIBRARY OCT 2 1 1989 K, RECEIVED^ NOV 2 9 19^1 ^^^2 2 1999 PSL 'D OCT 1 4 1999 lIBRARr, UNIVERSITY OF CALIFORNIA, DAVIS Book Slip-Series 458 3f^o?7 California. Dept, of Water Resoiirces. Bulletin, r ;» I 1 4 r> rn 1 ^ PHYSICAL SCIENCtS LIBRARY Call Number LFBRART UNIVERSITY OF CAUFOKMtt DAVIS 306027 00484 0123