Pililf?pili!lii:iii!!!!i!iil[ill:''!^ ,'(/.. •;1.< ;^/: THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA DAVIS EL CAPITAN DAM ON SAN DIEGO RIVER STATE OF C/ilFOR'-IA DEFARTI-SNT OF PUBLIC '.V'OFJCS rubli:;ations of the Lr\riSION OF '"ATER RESOURCES EB'''ARD ElfATT, State Engineer BULLETIN NO. 48 sa:' diec-0 ccui'ITY" investigation 1935 Pursuant to Chapter S'^S Statutes of 1933 (SEAL) LIBRARY U^^VER^i rV C!^ CAUFORNIA TABLE OF CONTENTS Page ACKNOVniEDGIIENT xiii ORG/ATIZATION xiv COITSULTAIIT ..____-__ j^v CHAPTER 278, STATUTES of 1933 _____ xvi EOPulWDKD --------------------- xvii Chapter I i:]TROCUCTION, SUia/IARY lim CONCLUSIONS 1 Watsr problems in San Liego County ------ 5 Previous investir.etions ----------- 6 Scope of present investigation -------- 8 Sumrnarj^ __-___--_--_--_---- lo Water Supply ----------------- 10 Present irrigation and urban development and v^ater supply utilization -------- 15 Water requirements -------------- 16 Elood control ------- --------- 17 Tia Juana Valley 20 Plan for conservation and flood control on San Liego River ------------- 20 Conservation reservoirs ---------- 21 Flood control -------------- 27 Conclusions ----------------- 30 ■11- TABLE OF CONTENTS, Continued. Chapter II Page WATER SUPPLY _--_ 34 Description of basins --------------- 34 Precipitation ------------------- 42 Relation of run-off and precipitation ------- 48 Run-off 50 Full natural run-off --------------- 52 Chapter III WATER SUPPLY DEV3L0PI.iENT AND UTILIZu^:TION IN SAN DIEGO COUNTY _______ 54 A-gencies furnishing water service --------- 66 Irrigation districts ------------- 67 Mutual vjater companies ------------ 71 Incorporated cities ------------- 75 Public utilities and private compejiies - - - - 82 U. S. Indian reservations ---------- 65 Individual private development ---------- 87 Utiliz?.tion of underground basins -------- 89 Grovrth and location of ii-rigated lands ------ 93 Present area e>nd value of irrigated and unirrigated crops ---------------- 95 Grovrth of urban areas --------------- 95 Siiminary of present utilization ---------- 100 ■111- TABLE OF CON^rZNTS, Continued. Chepter IV Page WATER REQUIRH-E^TTS 104 Estimated maximum safe yield of Pacific slope basins in San Diego County - - - - 105 Agricultural lands ----------- ___-- m Geology ------------------- ill Soils __-- 112 Soil classification ------------- 114 Future development of irrigable lands ------ 116 Population of urban areas ------------ 118 Future growth of population -------- 119 Estimated future water requirements ------ 123 Chapter V FLOOD CONTROL 127 Histoiy of floods in San Diego County ----- 128 Characteristics of flood occurrence ------ 130 Time of occurrence of flood flows ----- 13D Variation of intensities of flood flows - - 131 Size and frequency of flood flows -------- 136 Mean daily flood flows ------- - - 137 Flood hydrographs ------------- 138 Effect of conservation reservoirs ----- 143 Methods of flood control ------------ 144 Utilization of conservation reservoirs for flood control --------------- 145 Status of flood protection in San Diego County - - 149 Future flood control works --------- 150 Protection of Tia Juana River Valley ------ 153 -iv- Chapter VI Page CONSERVATION AND FLOOD CONTROL ''ORKS ON SAN DIEGO RIVER - - 156 Existing development ----------------- 157 Complete development for conservation and flood control-160 Conservation reservoirs ---------------- 163 Yield of San Diego River v;ith surface reservoirs - 166 Use of undergroiind reservoirs for seasonal and cyclic storage ----------------- 177 Cuyamaca reservoir ---------------- 180 El Capitan reservoir- -------------- I8I San Vicente reservoir -------------- 184 Mission Gorge No, 2 reservoir ---------- 194 KtLssion Gorge No. 3 reservoir ---------- 203 Comparison of reservoirs ------------- gi5 Flood control v«orks ------------------ 223 Channel improvement and relocation in Mission Bay area -------------------- 227 Reservoir control of floods ----------- 235 Protection of I\'dssion Bey area by combined flood control by reservoirs and improvement and reloca- tion of San Diego River channel -------- 245 Protection of Mission Valley ---------- 248 i-JTEIvIDIX A RESERVOIR OPERATION ON a'A^ rjEGO RIVER A-1 ■"ater supply of Sen Diego River ----------- A-1 Evaporation from water surfaces of reservoir in the Sen Diego River Basin ---------------- A-8 Net safe yield of Srn Diego River through coordinated operation of Cuyajn£.ca, El Capitan, Saji Vicente and Mission Gorge No. 2 reservoirs ----------- A-9 APPENDIX B MONTHLY PRECIPITATION AT IiHSCELLAI'JEOUS ST.-.TIONS IN S.AT DIEGO COUNTY ------------------- B-1 LIST OF TABLES Table Chapter II - 7/ater Supply Page 1. Areas and elevations of drainage basins in San Diego County- --------------- 41 2. Precipitation stations in or near San Diego County- - 43 3. Characteristics of precipitation at nine stati3)ns in San Diego County -------------- 45 4. Variation of precipitation vith elevation in the San Diego River drainage basin- -------- 47 5. Average precipitation at Cuyamaca and Grossnont in comparison with full natural flow of San Diego River ------------------ 49 6. Stream gaging stations on streams tributary to San Diego County- --------------- 53 7. Seasonal full natural run-off of principal streams of San Diego County -------------- 57 8. Average seasonal full natural run-off of streams tributary to San Diego County --------- 59 9. I'onthly distribution of run-off in typical seasons of record on three m.ajor streams in San Diego County- -------------------- «i 10. Maximum mean daily flows in principal streams tribu- tary to San Diego County- ----------- P3 Chapter III - Water Supply Development and Utilization in San Diego County 11. Reservoirs of the City of San Diego --------- 79 12. Growth of population and consumption of water in corporate limits of City of San Diego ----- 81 13. Eiiisting surface storage reservoirs in San Diego County- -------------------- 88 14. Growth of irrigated areas in San Diego County - - - - 94 - va Table LIST OF TABLES, Continued Page 15. Classification of crops in San Diego County by stream basins, 1934.- ------------ 96 16. Area and value of crops in San Diego County.- - - - 98 17. Population and assessed valuation of incorporated cities in San Diego County- --------- loo 18. Present water supply development in Son Diego County- --- - __________ 102 19. Estimated safe yield of existing v.'ator supply developments in Sen Diego County- ------ 103 Chapter IV - Water Requirements 20. Potential surface storage reservoirs in principal stream basins of San Diero County ------ 107 21. Estimated maximum safe yield from Pv-.cific slope basins tributary to Son Diego County. - - - - HO 22. Classification of lands of western S^n Diego County- ---------_-____---- 115 23. Net area and ultimate seasonal mater requirements for irrigable Innds in Sen Diego County- - - - 117 24. Gi-owth of population in incorporated cities in metropolitan area- -------------- igo 25. Estimated prst and future irrigation and metro- politan area water requirements of S..r. Diego County _--- 122 Chapter V - Flood Control 2P. Vtiriation of intensity of storm rainfall with elevation in Son Diego River drainage basin- - 133 27. Probable size and frequency of mean doily flood flows from drainage basins in San Diego County 139 28. Variations in crest-neen-daily-flow ratios with the areas of drainage b- sins rnd in different floods _____________ 140 29. Probable size and frequency of crest flood flows from drainage br.sins in San Diego County - - - 142 -vii- Table LIST OF TABLES, Continued Page 30. Rcl^'tion of irsijor flood flov:s to prior precipi- tation for San Diego River basin above Mission Gorge ---------------- 148 ?1. Fiill natural run-off of San Diftgo River at T'ission Gorge subsequent to April 1st in seasons in which the rainfall index was above 100- - - - 148 Chapter VI - Conservation and Flood Control Works on San Eiego River 32. Mean seasonal gross evaporation fror. pans in San Diego County- ---------------- 164 33. Drafts and evaporation from reservoirs- ------ 167 34. Summary of study to estimate safe yield cf San Diego River with coordinated operation of Cuyanaca, 31 Cspitan, San Vicente, and ?'isslrn Gorge Yo. 2 reservoirs ------------ 175 35. Safe yields of San Diegc River with additional reservoirs operating coordinately with Cuyamaca, and El Cspitan reservoirs- - -' - - - 17*^ 36. Areas and capacities of Cuyaraaca reservoir- — - - 18C 37. Areas and capacities of El Capitan reservoir- - - - 162 38. Areas and capacities of San Vicente reservoir - - - 185 39. Cost of San Vicente reservoir -- — - ------ 193 40. Costs of San Vicente reservoirs ----- ----- 194 41. Areas and capacities of Mission Gorge No. 2 reservoir ------------------ 195 42. Cost of I'ission Gorge Ko. 2 reservoir - — - - - - 202 43. Costs of ;.:ission Gorge No. 2 reservoirs ------ 203 . . '; ■ - '6- 44. Areas and capacities of Tission Gorge No. 3 reservoir ------------------ 205 45. Cost of Mission Gorge No. 3 reservoir with d£iin at lower site. ------- ---------- 214 4*>. Costs of Mission Gorge I'o. 3 reservoirs with dans at lower site.- --------------- 215 -viii- Tabic LIST OF TABLES, Continued Page 47. Comparison of conservation reservoirs -------- 218 48. Costs of additional safe yields from San Vicente and IJission Gorge reservoirs operated co- rrdinately with Cuyamaca and El Capitan reser- voirs --------------------- 222 49. Cost of channel improvenent and relocation for San Diego Rivfsr, Tission Bay to Presidio Hill 232 50. Costs of channel improvement end relocation for San Diego River, Mission Bay to Presidio Hill - 235 51. Effect of conservation reservoirs on San Diego River in roducinf: flood flows --------- 236 52. Cost of I'ission Gorge ITo. 2 reservoir v.'ith flood control features- ---------------- 240 53. Costs of rission Gorge !'o, 2 reservoirs v/ith flood control features- --- — - --------- 244 54. Costs of flood protection in T'ission Bay area - - - - 246 55. Cost of flood channel for San Diego River through Mission Valley- ------- __----_ 252 Appendix A A-1. Monthly full natural run-off of San Diego River in acre-feet ----------------- A-11 A-2. Loss in evaporation fror. reservoirs on San Diego River ----- ------- _____ a_i6 A-3. J'onthly drafts on reservoirs- ---------- — A-20 A-4. Coordinated operction of Cuyamaca, El Capitan, San Vinente and Mission Gorge No. 2 reservoirs on San Diego River, 1894-1933.- --- -__ a- 21 Appendix B B-1. Precipitation stations in or near Son Diego County- - B-3 B-2. Monthly precipitation at miscellaneous stations in San Diego County- -- ___-------- B-4 -IX- LIST OF PLATES El Capitan Dan on San Diego Piver Frontispiece Chapter II - V/ster Supply Plate Following Page I Principal draino{?e feasins and prccipitotion and stream gaging stations in Son Diego County ___-_--------------- 35 II Variations of precipitation with eltvction in Son Diego River droinrigo b^sin- ---------- 47 III Averrge precipitation et Cuy.'-.mr ca rnd Grossinont in compr.rison with full nr.turcl flow of Srn Diego River 49 rV Seasonal run-off of four mr. jor S<-n Diego County Streams -------------------- 60 Chapter III - Water Supply Development and Utilization in San Diego County V Water service areas of organized agencies in San Diego County- ---^--- — _____--_ 57 VI Growth of population and consumption of water in corporate limits of San Diego --------- 81 VII Principal underground reservoirs in Pacific slope basins of San Diego County- - - — _--_ 89 VIII Irrigated lands in San Diego County --------- 94 Chapter IV - Water Requirements EC Classification of soils in Western San Diego County - 114 X Water requirements of San Diego County with assvimed rates of future growth- _-__ 124 -X- Plate XI XII XIII XIV X7 X7I XVII xnii nx XX xn XXII xnii XXIV LIST OF PLATES, Continued. Following Page Probable frequency of gross yield of San Diego River -------------_--.-- 125 Chapter V - Flood Control Areas subject to flooding in Pacific slope basins of San Diego County --------------- 127 Time of occurrence of floods on two streams in San Diego County ---------------- 131 Variation of storm rainfall intensity in San Diego River drainage basin based on ten two-day periods, 1914-1917 ------- 131 Probable frequency of flood flows from drainage basins in San Diego County ----------- 133 Hydrographs of floods in streams of San Diego County - __---_- _________ 140 Chapter VI - Conservation and Flood Control Vjorks on San Diego River Location map of development of San Diego River - - 160 Profile of development of San Diego River ----- 16C Additional safe yields from San Vicente and Mission Gorge No, 2 reservoirs opereted coordinately with Cuyamaca and El Capitan reservoirs -------------------- 173 Combined operation of reservoirs on San Diego River - 175 San Vicente dem on San Vicente Creek, a tributary of San Diego River ----------------- 192 Cost of reservoir capacity and safe yield from San Vicente reservoir --------------- 218 Cost of reservoir capacity and safe yield from Mission Gorge No« 2 reservoir ----------- 219 Comparative costs of reservoirs on San Diego River 219 -XI- LIST OF PLATES, Continued. Pls'''®' Following page XXV Unit cost of additional safe yields from San Vicente and Mission Gorge No, 2 reservoirs operated coordinately with Cuyamaoa and El Capitan reservoirs --------- 222 XXVI Hydrographs of probable once-in-100-year flood in the Sen Diego River drainage basin- --------------_-_--___- 224 XXVII Channel improvement and relocation for San Diego River - Mission Bay to Presidio Hill 227 XXVIII Mission Gorge No, 2 dam on San Diego River, with flood control features ---------___ 238 XXIX Cost of flood protection in Mission Bay area 246 -xii- ACKITOWLEDGIIENT In the flood control investigation of the San Diego River and other streams in San Diego County £jid in the formulation of a plan for conservation and flood control of water originating in the San Diego River Basin, and a plan for flood control of the Tia Juana River between the international boundary line and the Pacific Ocean, most valuable assistance and cooperation have been received. I.fany individuals, irrigation districts and other public and private agencies have furnished data and in- formation v.'hich ware particularly useful in the prepara- tion of this report. Valuable cooperation has-been rendered by public officials of the City and the County of San Diego. -Xlll- ORGAinZATION Earl Lee Kelly Director of Public Works Edward Hyatt State Engineer This bulletin was prepared under tlie direction of A. D. Ednonston, Deputy State Engineer by p. H. Van Etten, Senior Hydraulic Engineer Assistants C. B. Meyer Garfield Stubblefield D. W. Morrison E. L, Wing Engineer - Geologists James C. Kimble Chester T.larliave Delineators J. L. James E. N. Savrtelle Chapter VI on Conservation and Flood Control V/orks on San Diego River was compiled by T. B. Waddell, Supervising Hydraulic Engineer J. J. Haley, Jr. Administrative Assistant -XIV- CONSULTANT Thomas H. King,* Consulting Engineer, acted in an advisory capacity during the prelirflinary stages of the investigation. * Since deceased. -XV- CKAPTEE 278, STATUTES OF 1933 Item 156 — For flood control investigation of the San Diego River and other streams in San Diego County in cooperation v;ith San Diego County and other agen- cies, to be expended under the authority and di- rection of the State Department of Public Works, twelve thousand dollars, provided that one-half of the money hereby appropriated shall not be- come available for expenditure unless the sum of six thousand do].lars ($6,000.00) (from other than State revenues) shall have been paid and deposited in trust with the State Treasurer on or before July 5, 1933, and the balance thereof until a like sum of six thousand dollars (^5,000,00) shall have been paid and deposited in trust with the State Treasurer on or before January 1, 1934, to match the sum herein appropriated for expendi- ture for the same purpose as that for -vvhich this appropriation is made. No money hereby appropriated shall become available for expenditure until at least the stun of six thousand dollars ($6,000.00) shall have been paid in trust with the State Treasurer by San Diego County $12,000,00 -XVI- FOREWORD This bulletin has been prepared by the Division of Water Resources of the State Departiaent of Public Works in cooperation with the Couaty of San Diego and the City of San Diego, This report presents detailed data and information on the water supplies and agricultural lands of San Diego County, the present status of irrigation and donestic and municipal water supply developnents; the utilization of water supplies from surface and underground sources; the irrigable lands end water reo^uirenents end the domestic and municipal water requirements of the metropolitan area; the flood flows of the princip?JL streams and probable frequency of occurrence; and presents a plan for the complete development of the vrater resources of the San Diego River Basin and flood control of the San Diego River in the llission Bey area. -xvii- CHAPTER I nJTRODUCTION, SIM'^JiY MTD CONCLUSIONS Sein Diego County occupies the most southwesterly comer of continent- al United States being bovinded en the south by the international boundary line between United States and Mexico and by the Pacific Ocean on the Trest, Orange and Riverside counties adjoin the county on the north and Imperial county lies to the east. The county approaches a rectangle in sliapc having a width north and south of about 50 miles and a length east and vrest of about 70 miles. The topography of the larger part of tho co^mty is moimtainous. The Peninsula Range crosses the co'inty rmming in a southeasterly direction with approximately two- thirds of tho area of the county lying west of tho divide. The range is rugged with several peaks over 6,500 foot in elevation. Its easterly slope is precipitous and drains into tho Great Basin of the Colorado Rivor, Seven principal strcjoms of the county drain the westerly slope of the range raid discharge into the Pacific Ocean. Thoy arc, from north to south, Santa Margarita, Sun Luis Rcy, San Dieguito, San Diego, Sweetwater, Otay >xn& Tia Juana rivers. Broad gently sloping mesas border the coast line south of the Santa Marj^-arita River and merge into the rough vrostorly slope of tho Peninsula Rcuigc about 15 miles from the coast lino. San Diego County has an area of 4,221 square miles of which 1300 square miles were included in ranches and farms, and 2S6 square miles or 144, 6C0 acres were classified as crop Irnd in 1950, Agriculture is one of tho principal industries of the coimty and tho United States Census reported the vcduc in 1950 of l^.nd, buildings, cquipncnt nnd live stock utilized in tho industry to bo about C;92,000y000, Approximctoly 285,000 acres of good r^riciiltural lands lie -X- on the Pacific slope, Ccnaitions are suitable for the production of a large variety of crops including many semi-tropical fruits and v;inter ve{ietables among which are avocados, oranges and lemons, celery, tomatoes and Irish potatoes. Dairying and the raising of beef cattle and poultry also are impor- tant industries. The v-.lue of crops and live stock products in 1929 were re- ported by the U. S. Census to be $13,500,000. The most important manufacturing industry in San Diego Co\m;y is the canning of fishery products. The excellent harbor and the proximity to Mexict-n v.'atcrs from v;hich tuna and tunalike fish are obtained places San Diogo in an important position in the fish canning industry of the State. In 1929 the value of canned products of the sea was $5,557,000 or about 19 per cent of the total for the State. Sixteen different commercial minerals were produced in 1930 valued at $1,503,047. ConsidorLble activity hc:s recently been shown in the old rold raining district around Julian. Practically all the electric energy used in San Diego County is gene- rated in the county. The power plants in the county have an installed capacity of 91,000 kilovolt amperes for steam electric and 1,100 kilovolt amperes for hydroelectric generation and in 1933 produced a total of about 180,000,00 kilo- watt hours of which 174,000,000 kilovjatt ricurs were generated by the steam plants. The country is v;ell surved by transportation facilities. Tivo trans- continental railroad systems hav.^ lines terminating in San Diego. The Atchison, Topeka and Santa Fe Eaili/ay traverses the coast secti m v/ith branch lines run-- ning inland to Fallbrook and Escondido and gives rail transportati-n to the east via Los Angeles, The San Diof;o and Arizona Railv.ay extends east alone the south boundary of the county, part of its route lying in liexico, and connects with the Southern Pacific main lines at Yuma, Arizona. It lias a branch lino running in- land to La l.Iesa, El Cajon and Lakeside, Pavcd highways extend throughout most -2- of the developed areas and excellent dirt roads serve the balance of the county, San Diego is the most southerly port jn the Pacific Coast of the United States, and the first as well as the last port of call for v^essels operat- ing through the Panana Canal in intercoastal and foreign trade. San Diego Harbor, one of the few naturr.l, deep v/ater harbors on the Pacific Coast, is landlocked, and easily accessible for all types of vessels in all kinds of weather conditions. The needs of the port are v/ell met by the important steam- ship lines v/liich offer frequent and rerular sailings to the Atlantic, Gulf and Pacific ports and to the principal ports of Europe, The commerce during 1029 amounted to 958,100 short tons v/ith a value of $47,500,000. Of this tonnage, 52,414 consisted of imports and exports while domestic coastwise shipments, both intercoastal and from Pacific Coast ports amounted to 905,686 short tons. The principal coastvvise receipts consisted of petroleym products and lumber and logs, v;ldle the principal shipments com- prised fish, fruit and vegetables, soap and soap powder and cotton. The prin- cipal imports vrere fish, sand, stone and ceiaent, steel and paper. The principal exports were cotton, feed consisting largely of cottonseed neal and cake, clay and petroleum products and su^-'ar. The port of San Diego is admirably situated to be of service in the development of the lov;er section of the State and affords an advantageous outlet for agricultural products of the Imperial Valley. Because of the 3trate:'~ic location of San Diego's excellent harbor, the United States Navy Departm.ent has developed an important ncval operating base at this port. The Destroyer Base, the Naval Training School, the large air station on North Island, and the Lfeirine Corps Base are some of the naval establishments in this vicinity. A mooring mast for dirigibles has been con- structed at Camp Kearney on Linda Vista Mesa, The United States Arraj'- maintains a large air force at Rockv/ell Field v;hich is also located on North Island and coast defense works at Fort Rosecrans on the Military Reservation on -3- point Loma. More than $40,000,000 ha'v^been invested in this vicinity by the War and Navy Departments. San Die^o County is fortunate in the many advantages v;hich nature has given it as a, recreational and residential arsa. The equable climate along the coast, warm in the winter and corapart-'tively cool in rummer, attracts thou- sands of vacationists each year, many of v;hom remain or later return to become permanent residents. Extending as it does from the Pacific Ocean across the mountains to the desert of the Imperial Valley in sn airline distt-nce of less than 80 miles, the county contains a varied scenery vjhich may be found few other places. The many state perks comprise large areas for the use of the public. In Borrego Desert Perk, Cuyejnaca Rancho Perk containing one of the highest peaks in the county, Mssion Bay Park, and Silver Strand Beach, the state has provided vacation areas of outstanding interest . Cleveland National Forest embraces a great deal of the higher mountrin re.3ion and the United States Forest Service has developed many areas for s'ommer c?mps and homes, Mtmy of the ocean beaches are ovmed by the municipalities adjoining them and are open to the public at all tines. Several yacht harbors on San Di'3co Bay rrovide safe anchorage for small boats and Dleasure craft . Tima, yellov: tril, marlin and other fish found in the adjacent waters of the Pacific have made San Diego famous for its sport fishing. In addition to the advantages provided by nature the various communi- ties of the county have provided many social advantages. The San Diego Zoo and the museuia in Balboa Park aro outstanding among their kind. Many schools, both public and private, are available. There are twelve public high schools, six of v/hich are in the urban area surrounding San Diego Bay. The San Diego State Teacher's College provides four- year courses of advanced study. The 1930 population of San Diigo County was 809,659 or 3.7 per cent of the population of the entire State. More than 80 per cent of the population -4- live in the eight incorporated cities. The largest city, San Diego, had a population of 147,995 in 1930 and the metropolitan area vjhich centers in that city and includes National City, Coronado, Chula Vista, La Mesaj and El Cajon had a population of 168,153. Oceanside and Escondido in tho northern part of the county have populations of r.bout 3500 each. The population of San Diego County increased 97,411 in the decade 1920 to 1930 or 87 per cent as compared to a 65 per cent increase for the entire State. The population of the metropolitan area increased 91 per cent during the same period. Water Problems in San Diego County « San Diego County's vaater problems arise from the extreme inequalities in seasonal and cyclic distribution of its viater resources and from the limi- ted supplies neturclly available as related to its present and future needs. The water problems involve the conservation and utilization of its water resources 8,nd tho control of floods* The v;ide renge of run-off varying from almost no run-off in some years to several hundred per cent of normal in exceptional flood years necessitates the construction and utilization of large surface storage reservoirs and the utilization of available underjsent Investigation . The present invest igstion authorized by Chapter E78, Statutes of 1933, has been confined to the determination of the v;ater supplies naturally tributary to San Diego County and the ultimate water requirements of the county, tc the formulation of a plan for conservation of v;ater for domestic, munici- pal and irrigation uses and control of floods in the San Diego River Basin, and the formulation of a plan for control of floods of the Tia Juana River between the international boundary line and the Pacific Ocean, Water supply studies vjere made to estimate the run-offs of the various stream basins for the 46-year period 1887 to 1933, The estimates for the entire period were based on stream flow measurements vfhich began in the season of 1887- 1888. Estimates of run-off for the San Diego River Basin were also made begin- ning with the season of 1883-1884, for the four seasons 1883-04 to 1886-87, *Bulletin No, 25, "Report to Legislature of 1931 on State Water Plan." Division of Water Resources, State Department of Public Works, 1930. ''*Bulletin No. 43, "Value and Cost of Water for Irrigation in Coastal Plain of Southern California," nrepareo. under cooperative agreement between the College of Agriculture, University of California and the Division of Water Resources, State Department of Public TJorlcs, 1933, -8- inclusive, from records of precipitrtion. Seasonal estimates of full netursil run-offs were me.de for all the principal stream basins, and mean seasonal esti- mates v;ere made of full naturel run-offs of luinor stream basins. The full natural run-offs of the San Diego River Basin -.vere determined at the dam sites of potential reservoirs and used to determine the required reservoir capacities and to estimate the annual safe yields obtainable from coordinate operation of potential surface reservoirs vjith existing developments, A crop and irrigated land survey was undertaken in cooperation with the County of San Diego end the State Emergency Relief Administration to deter- mine the location and areas of the different kinds of crops grovm, both irrigated and unirrigated, and the sources of water supply for the irrigated lands. The survey has not been completed and only the d£:.ta secured in San Diego, Sweetvmter, Otay and Tia Juana river basins are included in this report. Topographic surveys were made of the Mission B?y area and Mission Valley on the San Diego River and of the Tis Juana River Valley from the inter- national boundary to the Pacific Ocean. A geologic study was made to estimate the capacity of Llission Valley and upper San Diego River Valley underground reservoirs. Valuations were obtcined of reservoir and channel rights of way. Geologic studies were made of all deja sites considered in the San Diego River Basin. From the geologic deta secured, estimates were laade of the depth of excavation necessary to obtain satisfactory foundations for the dams. Data were obtained on unit costs of materials and labor and on the probable length of time required for construction, V'ith these data and the estimated quantities involved in the different parts of the construction, estimates were made of the costs of dams, reservoirs and leveed channels. Data were obtained on the costs of operation, maintenance and depre- ciation of the different features of the physical works and with these data and estimated interest and amortization charges, estimates were made of annual costs and of \uiit costs of safe yields obtainable from surface storage reser- voirs. Estimates were made of the maximum flood flows which mi(T;ht occur at certain intervals of time at various points on the principal streams and the effects of conservation and flood control reservoirs in reducing the sizes of these flows in the San Diego River Basin. Leveed chaimols were designed for reclamation of flooded areas in Mission Valley, for improvement and relocation cf the San Diego River in the Mission Bay area and for the reclamation of flood- ed areas in the Tie Juana River Valley. Data were obtained on the value of lands subject to inundation in Mission Valley and Tia Juana River Valley, and the economic feasibility of reclamation of those areas was studied, SUHMARY lu the following chapters of this report, there are presented in de- tail the basic studies and investigations of water r&sourcus and water re- quirements, existing development, and probable frequency and size of flood flows; plans of development and operation for conservation of waters of the San Diego River Basin and for flood control of the San Diego River in Mission V.^lley and I^ssion Bay area; and for flood control in the Tia Juana River Valley, T 'ose arc briefly summarized in the remaining portion of this chapter. Water Supply The precipitation on the Pacific slope of San Diego Coiuity is extronely variable both geographically and seasonally. The nean seasonal precipitation varies from about ten inches per season along the coast to about forty inches por season on the higher mountain peaks. From season to season the precipitation may vary from a minimum of about 40 per cent to a maximum of approximately 200 per cent of the moan seasonal rainfall. It occurs chiefly in the form of rain. -10- Although there is usually some snowfall at the higher olevp.tions every y^ar, it usually melts away rapidly without ajiy merked effect in changing the run- off from whet it would have boon had the precipitation occurred in the form of rain. On the average, over seventy per cent of the toteil seasonal precip- itation may be expected to occur in the four winter months from December to March, inclusive, and only about five per cent in the four summer months from June to September, inclusive, v.-hen the irrigation demand is at its peak. Avail- able precipitation records which have not been published by the United States Weather Bureau are given in Appendix B, The Pacific slope of San Diego County is drained by many independent streams having basins ranging from a few to over 500 square miles in extent. For the purposes of this report these basins have been grouped into seven principal and four minor divisions. The group of principal basins comprises the Santa Margarita, San Luis Rey, San Dieguito, San Diee;o, Sweetwater, Otay, and Tia Juana river basins, 01' these the Santa Margarita River on the north and the Tia Juana River on the south drain large areas outside of San Diego County. The minor basins are made up by grouping the smaller stream basins of the c.reas betvreen the northern boundary of the county and Santa Margarita River, between San Luis Rey River and Escondido Creek, between San Dieguito River and Tecolate Valley, and between Switzer Canyon and Otay River. In practically all of these basins potential reservoir sites may be found, many of which arc low enough on the streams to conserve the greater part of the run-off of the basins. The following tabulation shows the mean seasonal full natural run-off for the 46-year period from 1887 to 1933, from the portions of the several drainage basins above and belov; the lowest potential reservoir site in each basin. •11- IJIEAN SK\.S0:TAL full Natural RUIJ-OFFS op SM :.I3G0 COUI.'TY S?R2a?.TS 1887 - 1933 Str.ar. or atroam group Above lowest potential reservoir Artia of basin, in square miles Principal Basins Santa itargarita River San Luis Rey River San Dieguito River San Diego River Sweetwater River Otay River Tia Juana River Totals, principal basins ;.Iinor Basins t San Mateo Creek to Aliso Greek Loma Alto Creek to Escondido Creek San Li been one of the major factors in attracting large numbers of -neople from other ptrts of the United States, end is responsible to a L-rrge degree for th?. cxtromely rapid grovth in popula- tion. Major v;eter surply nrojucti; nave been constructed on all the prin- cipal strocjns tributary to Sesi Diego County v.'ith the exception of the Santa Margcrita River, About onu-third of the v;atcr utilized in 1933 was secured by pumping from underground rcsei-voirs and tvo- thirds by diversion and surface storage. The total capital investment in vatur supply v;orks was vclued at 1^33,527,000 in 1933, of wnich ;;21,365,000 v/as the valuation of the City of -15- Sen Diego's v/cter system. The cstimr.ted safe yield for rll existing wr.ter supply development in th-i county including El Crpitr.n I^esorvoir recently constructed by tho City of Sen Diego r.jnoimts to 79,000 r.crc-feet annually* Water Requirorients . Vrtiile the usos of wr.tor in Sen Diogo County zre vr.ried, the consunrp- tive uses for irrigation, domestic end municipcl purposes predominate. As tho urbfji populrtion is proportionately Ic.rge the use of water for domestic sad municipal purposes amounts to cbout 30 per cent of the total consumptive us J in the county. The local water resources arc limited rnd deficient in amount to meet the ultima.te v;?.ter requirements of the county, Tho estima.ted raE.ximum safe yield from Pacific slope basins of the county v;ithout consideration of cost or economic feasibility amounts to about 150,000 acre- feet annually. The ultimate water requirements for all irrigable lands in the county amount to arproximately 512,000 acre-feet annually and are shovm in the following table. ULTIT,!ATE SSASONAl. WATER EEQUIRE!.IEI>'TS FOR irmiGABLE LAI^IDS IN SM DIEGO COUNTY ; Gross allowance. Net allowance, at : : Soil area Total net irri- rat average rate average rate of : gable area, in •of 1.30 acre- 1.25 acre- feet : acres : faet vev acre per acre : : Capistrano 42,200 56,200 54,000 : : Oceanside 129,800 168,600 162,300 : : El Cajon 57,200 74,400 71,500 : : Highland valleys 10,000 15,000 12,500 : : Totals 240,200 312, 20C 300.500 : The items "gross and net allowance" are defined as follows: "Gross allowance" designates the amount of v/tter diverted at the source of supply ♦ "Net allowance" designates the rjnount of water actually delivered to the area served. -16- As the future growth of the metropolitan population will probably occupy lands of low soil rating not classed as irrigable, the ultimate annual water requirement for the entire county will ejnount to 312,000 acre- feet plus the requirement for municipal purposes in the metropolitan area. In 1933, £pproxime.te].y one-half of the ultimate development and utilization of the locel water rosourccs had occurred. As the unit use per e.cre for irrigation and domestic use is about the seme, the local supplies will meet the water requirements of e tot?l area of irrigated and urban lejid of approximately 185,000 acres. Should the irrigation development and use continue to increase et the spme average rate that it has during the past forty years, or since the first major water supply developments were made, until 1965, resulting in an irrigated area of about 75,000 acres, only suf- ficient local w&ter supplies can be developed to meet this irrigation use and in addition meet municipal and domestic demands sufficient to support an urban population of not more than 500,000. Flood Control . Although the valleys through ;\'hich the streams of San Diego County reach the ocean are relatively small, they comprise a large area of good agricultural soils. During major floods, such as that of January 1916 which destroyed agricultural lands valued at $1,500,000, the valley areas are subject to destruction by either erosion or the deposition of sand and other debris. At the present time permanent improvements are being made within the flood planes of rj:.-ry of the major streams and, in urbar. areas, residential districts have encroached on many of the minor channels. From the available data on flood occurrences since the advent of the white race in 1769 it seems nrobable that floods comparable to that of 1916 may be expected to occur about once in from 30 to 40 years on the average. -17- Analyses of the frequency of occurrence of floods on tlie major 3tronr.i3 of S'ln Diego County under present conditions of water development indicate crest flows as shown in the following tabulation. As potential conservation res- ervoirs are built these values will decrease. This decrease will be most marked on the smaller floods, v/:iile those which na;/ be expected at long intervals will not, as a rule, be greatly reduced. PROBABLE SIZE .UID FREtiUENCY OP ClffiST FLOOD FLOV.'S FHO.I DRAIiaOE BASIN3 I.J SAM DIEGO GOmJTY : Average Crest flow, in second fee Jt, J : Drainage basin "Area, in< square elevation, . in occurring once in 25 ! 50 ; 100 250 miles feet years • years : years years : ; Santa Margarita Hivei : at Ysidora 743 ! 2,302 • 30,500 i ; J 44,500 ! 62,800 t : 85,700 :San Luis Rey River • at Oceans ide (1) 359 (1) 1,442 (Ih • 28,600 . (1): 41,800 • (1) 58,000 • 80,500 : ;San Dieguito River : at Hodges Dam ! > 503 1,965 f J . 45,900 64,600 88,400 •119,000 : ;San Diego River ; ^t San Diego t 435 1,843 i (2) 26,000 • (2) 46,600 (2) 71,600 i (2) i • 99,200 : tSweetwater River ; at Sweetwater Dam , 181 t 2,393 ; 19,100 . 29,600 ! 42,400 61,100 J t i 173,000 : » « • :TiJi. Jujjia River ! ne -.r Nestor : 1,653 ; unknovm 40,000 1 80,000 ! 121,000 : (1) Excluding area of drainage b..3in above Henshaw Darn. (2) The regulating effect of El Cii-pitan Reservoir has been included in these values. Although the intensity of the precipitation increases to a m:irked degree with altitude .ind distance from the coast, the geologic nature of soils is such that the coastal areas conyosed of w.uer borne materials underlain by h-.rdpan may be expected to yield practically as large flood flows per square mile as the higner mountain soils of a sandy nature underlain by deep beds of disintegrated granite. -18- Flood control may be obtained either by systems of levoes, by storing flows in excess of chennel capacities in reservoirs, or by combining these two methods. The hydrogrephic characteristics of the San Diego County floods, caused almost entirely by rainfall rnd coming from relatively smdl drainage basins, aro. such that control by reservoirs is particularly favorable. The value of water in Sen Diego County for domestic and agricultural purposes, however, is such that conser-vation must be given a first claim to the available reservoir space. In many cases relatively small increases in the heights of the dams vail provide adequate reservoir space for flood control purposes. At the present time very little has been done to control the floods in San Diego County except for the regulation afforded by conservation reser- voirs. A small levee has been built for the purpose of preventing the over- flow of the Tia Juana River into San Diego Bay; the Federal Government has constructed a dyke from Old Town to Point Loma, turning the San Diego River into Mission Bay; some bank protection has been built by individual owners; and some channel straightening and brushing has been done in connection with unemployment relief projects. The ereas of agricultural lends subject to flooding are so small in relation to the lengths of the stream channels that control of the floods through the construction of levees will be extremely exDensive. The mainten- ance of cleared channels together with some revetment vork, however, v;ould reduce the tendency of the channels to wander end might result in the erosion of the chejinel and increased chexmel capacity r.dequatc for the smaller floods. Further protection against the smsJler floods v:ill come with full conservation development and, rhere economically feasible, space mey be provided in the upper parts of the conservation reservoirs or leveed cheimels constructed for protection against the larger floods. Until such time, it must be borne in mind that practically the entire valley floors of the ne.jor strea::i basins are •19- subject to overflow and that permanent improvements in these areas will be subject to serious damage during major floods, Ti a Juana VaUpy - In the Tia Juana River Valley between the international boundary and the Panific Ocean, some 4,670 a'^res are subject to overflow in time of flood. Of this area, 700 acres are now in river channe] and will be required for that purpose in the future, 960 aores are marsh lands v;hich are not of any great agricultural value at the present time, and 1150 acres are class 3 soils lying in the path of probable floods. Of the remaining 1,860 acres of class 1 soils subject to overflow, only about 980 acros are in serious danger of erosion or debris deposition. It has been estimated that an adequate system of levees for the protection of these lands would cost slightly over $1,000,000. These levees vjould give full protection to some 3,000 acres of agricultural lands, only about 2,100 of v;hi ?h are in serious danger of des- truction. Such protection would enable the farmers to live on their lands and permit the development of an urban center in the Tia Juana Valley, Since large areas suitable for residential purposes are situated adjacent to the valley above the flooded area, and the cost per acre for reclaiming the area in jeopardy would be large, it is not believed that so large an expenditure could be justified at the present time. Plan for Conservation and Flood Control on San Diego River . The plan presented herein comprehends the most economic development, conservation, utilization and control of the water reso\irces of the San Diego River for all consumptive purposes, and flood control, in coordination with existing developments. The plan is based primarily upon conservation and uti- lization of water for domestic, municipal and irrigation purpos<=>s and is for the complete development of the San Diego River Basin without consideration of the possibility of storing water imported from other watersheds in reservoirs ■20- constructed within the basin. As the Supreme Court of the State of Celifomia has confirmed the paramount right of the City of San Diego to the waters of the San Diego River, £jid as the construction of additional storage v.-orks will present no different legal problems than may arise from the recently constructed El Capitan Reser- voir, no allowance has been made and no costs included in the estimates for water rights or litigation arising therefrom. The plan presented for the complete development of the San Diego River Basin includes the construction of two additional reservoirs, San Vicente reservoir on San Vicente Creek to regulate and conserve the run-off of that creek and waters diverted by gravity from the El Capitan reservoir, and Mission Gorge No. 2 reservoir to regulate and conserve the run-off originating below Sen Vicente and El Capitan dam sites, and an improvement and relocation of the San Diego River from Presidio Kill, Old Tov.-n, to Mission Bayi £o^se^rvaJti_on_Re_servo^r_s - Tlie Sen Vicente teservoir site is located in San Vicente Creek Canyon \;hich has a comparatively flat gradient and steep sides. The reservoir site is en excellent one for cyclic storage, having only about 80^ of the surface area of El Capitan Reservoir for the same capacity, with correspondingly greater efficiency in preventing evaporation losses. It is located at an elevation sufficiently lower than El Capitan Reservoir to allow transfer of v/ater by gravity from the latter reservoir at many stages of the two reservoirs. The storage capacity of 174,500 acre-feet, v.hich would be provided by a dam 263 feet in height, has been selected es that giving the maximum additional safe yield with transfer of v;ater from SI Capitan Reservoir. The reservoir site has greater capacity than thrt selected and additional storage at a relatively lov: cost may be secured for imported water when such storage becomes desirable. Under the method of operation selected, this reser- voir would be reserved for long time cyclic storage and water would be withdrav.-n -21- only after the other reservoirs vjere empty. The San Vicente d&m 3ite on San Vicente Creek is located about a half mile above Foster. It is underlain by eji old metamorphosed series of rocks, mostly granitic in character and, vhile additional explorations should be made before the final location of a dan at this site is chosen, the founda- tion appears satisfactory for a gravity concrete dam of the height selected. The Mission Gorge No. 2 dam site is located on the Sen Ciefo River near the head of Mission Gorge and the reservoir site covers the lower end of the upper San Liego River Valley. The reservoir would be comparatively shallow v;ith a large surface exposure which would result in large evaporation losses if used for cyclic storage. For this reason, a comparatively small capacity has been selected for this site and a method of operation used whereby the water stored in this reservoir would be drawn on first and the reservoir emptied as rapidly as possible. This method of operation allows the use of a smaller reservoir as it ivould be empty at the beginning of the majority of rvin-off seasons. A storage capacity of 29,200 acre-feet, created by a gravity concrete dam 109 feet in height, has been selected as that required to regulate and conserve the run-off not regulated by the San Vicente and El Capitan reservoirs. About two thirds of the lands in the reservoir site are of low soil rating and the underground basin v/ithin the site is very shallow and hes little storage capacity. The Mission Gorge No. 2 d?m site lies in an area of granite. Hard and massive bed rock is exposed in the stream bed and v;hile considerable talus covers the lower portion of the left abutment, and deep weathering has occur- red on the right abutment, it is believed that excavation and stripping to a reasonable depth v;ill expose rock over the entire site suitable for satis- factory foundation for a masonry- dam. Although a number of test pits have been dug in the abutments, and a number of holes drilled in the bottom of the -22- canyon, further explorstions should be mede before e finel location for eny dai.-i at this site is selected. Before e reservoir Gite wr.s selected on the lower reaches of the S&n Diego River, studies Vvere made of both Ivlission Gorge No. 2 and Ivlission Gorge No» 3 sites. Mission Gorge No. G dera site is located ^bout 2,3 miles dovm- streani from the line betvreen the Ex Mission Sen Diego and El Cajon grants end a short disttuice above the lower end of Mission Gorge, Investigation showed thc.t a loose wedge of rock existed in the lower -oortion of the right abutment of the site v;hich has been coimionly accepted for Mission Gorge No, 3 dam, lo- cated just dovmstream from the sign "Mission-Gorge Bam Site No. 3" painted on the rocks on the right bank of the river. As the large amount of excavation necessary to remove this loose v^edge of rock would greatly increase the costs of drjns at this site, the csnj'^on was studied for other sites for several thcuscjid feet upstreem and for some distance dovmstream. The best site appeai-ed to be one located about ?00 feet doT.vnstream from the previously mentioned sign and 200 feet bolow the criprinal site. The detemint-tion of the relative merits of the different reservoir sites considered has been viv.de from cov.parisons of additional safe yields obtainable and comparisons of ce^ital, annual and unit costs. The capital cost estimates are based upon present costs of Irbor end material ?.s determined from construction costs of similrr structures, and upon costs of rights of v;ay estimated from valuations made by Tax Factors, Incoi-porated, in 1929, except for the San Vicente site v;hero- actual costs of lends were used. Dams of gravity concrete type, straight in plan, w^ere selected for use at all sites considered. Other types of dams could be used et each of the three sites end final con- struction plans may shov; that tr.e use of another type of dam will result in reducing the cost. ViThile rights of way costs used are considered a fair ■23- vnluu of their present north, conditions pos-ibly may arise whereby these values \7ould be changed. ;j.l factors involved must be evaluated finally at the time actual construction is conter.iplated. Hooi'ever, a very material chance in these factors wouJ.d have to ocur before the econonic advrntagos of the sites selected would be altered. The follouing tabulation sho'ws tho capital and annual costs of the San Vicente and Mission Gorge reservoirs, the additional safe yields obtainable with thosn reservoirs operated coordinatcly v/ith the existing Cuyaznaca and El Capitan rosorvoirs, and the unit costs of addi- tional safe yield, for sovcral oi3os of reservoir at each of the throe sites, CKvi'Ai-usoi'; OF co:ts of R;;s::iRVciR3 Addi- Capital Unit Cost Storage : Hoight . tionca : Cost of : cost of capacity of • sufo reservoir of ■ additional : Reservoir in acre- dam, in yield, in storaf.e, per safe yield, per foot feet ac re- Capital Annual acre- acre- fect • foot foot :San Vicente 100,800 209 8,800 ^3,912,000 .^?252,900 C38,80 :-':28.70 130,000 234 11,700 4,904,000 , 317,600 37.70 27.10 158,400 256 14,500 5,814,000 377,100 56.70 26.00 174,500 268 16,200 6,519,000 423,100 . 37.40 26.10 : Mission :G-orgG No, 2 29,200 109 2,700 2,145,000 137,800 73.40' 51.00 57,600 122 4,300 2,960,000 187,900 51. 4r 45 . 70 86,800 151 5,000 3,435,000 217,200 : 39.60 . 37.40 :Mission : Gorge No. 3 29,200 : 231 : 5,300 3,666,000 237,100 : 125.50 : 74.10 :with dams at : 57,900 : 252 5,000 . 4,870,000 ol3,000 : 84.10 . 62 .80 : lor/or site : 87,60C 263 : 5,700 5,808,000 373,100 : 86.30 55.70 .24- Mission Gorge No 3 reservoir v/ould give e som3v;hat greater yield than the No. 2 reser'/oir due to greater average water depth and less evapci-- .'tion loss for p11 r.izes considered. Eowever, th ■ much greater heights of Oara i'cr Mission Gorge No. ? site increase the costs to such p. degr-^^e that the resultant unit costs of additional safe yield are materitlly greater for I'iission Gorge No. 3 reservoir then for the No. £ reservoir. Also the greater surfece area of the Mission Gorge No, k reservoir allows greater flood conti-ol regulation v.ith less increase in dan height. Therefore, the Mission Gorge No, 2 reservoir has been selected as Triore econoraic than Mission Gorge No, 3 res- ervoir for the lov;est reservoir on the Sen I'iego River, As previously stated, the plan for the complete development of the water resources of the S?tl Diogo River Basin includes the construction of both the San Vicente and IvLission Gorge No, 2 reservoirs. Under the method of operation adopted, San Vicente, Mission Gorge Ho, 2 end the existing Cuyamaca and El Capitan reser^/oirs v;ould be operated coordiuatoly. a'ater from El Capitan Reservoir would be diverted by gravity to Saxi Vice-ite reservoir. The inflow into Cuyamaca Reseivoir v;ould be stored in that reservoir until Ms.y 1st anc then released as rapidly as possible to El Capitan Reser/oir if storage y;as available, or as fast rs storage became avaiipble. An irrigation draft of 5,000 acre-feet per season v/as dra-vvn from El Capitan Reservoir, or from San Vicente v.hen El Capitrn v;rs empty. Water for other uses v^as dravm from Mission Gorge No. 2 and El Cepitrn, in order, u:itil etch v;as empty and then from San Vicente resei-voir. This aethoc of draft v/ould reduce evaporation losses to a minifflur.1 by retaining v/ator longest in the reservoirs v;ith the smallest evaporation losses. This method of operation v.ould give a total safe yieJd from the San Diego River Basin of 32,500 acre- feet per year or 29.0 millions of gallons per day, or en additional safe yield for San Vicente and Mission ■25- Gorge No. 2 reservoirs of 18,500 acre-feet ner year or 16.5 nillions of gal- lons per day. If Mission Gorge No. 3 reservoir v/ith a crpacity of 29,200 acre-feet v,ere used in this coordinated operation instead of Mission Gorge No. 2 reservoir, the additional safe yield would be increased only 300 e ore- feet per year and, es just shov.Ti, the unit fost of water v/ould be greatly increased. In estimating the costs of additional safe yield from the San Diego River Basin, it has been assumed that v/hen additional or complete development is made, the agency making the development v.'ill determine where the water will be utilized and v.'ill provide the necessary' transmission and distribution fa- cilities for utilization for consurnptive purposes. Therefore, only costs of storage and development have been included in the estimates shown. It has been assumed that the transfer of water from El Capitan Reservoir to San Vicente Reservoir will be made through the transmission pipe lines. These transmission lines will be interconnected at Lakeside £jid all transfer of water may be made when these pipe lines are being only partially utilized for transmission purposes. The costs of the eclditional consaj^ation developments estimated on the foregoing described bases are given in the following table. ■26- COST OF AEDITIONAL COKSEKVATION DEVELOPIENT Or SAN DIEGO RIVER San Vicente Reservoir 174,500 acre-feet Mission Gorge No. 2 Reservoir 29,200 a^re-feet Additional storage capacity 203,700 acre-feet : Reservoir Addi1 safe ' . ,^ 'Cost of reservoirs' yield : : Cost of additional : safe yield : Acre feet per I''illicns: of : Capital gallons: Annual Capital Unit ; per : per V'-. r : . year per day: acre- foot acre- foot million : ptr vear gallons : (1) (1): " (1) (1) (1) : : San Vicente : 16, 200 14.5 16,519,000 $423,100 $402.40 5?26.10 182.20 : : Islission C-org' 3 (1) (1): ': (1) (1) (1) : No. 2 : 2,700 : 2.4 :2, 145, 000 : 137,800 . 793.70 51.00 : 156.70 : •.Totals for : coordinate ; : operation 18,500: 16.5 $8,662,000 §550,900: $468.20 : §30,30 : $93.00 : :with exist- :inc reser- :voirs (1) Additional safe yields ."nd costs with each reservoir operated coordinately vrith existing development. Flood £ont£oj^ - The operation of Cuyanaca, El Capitan, San Vicente and Mission Gorge No. 2 reservoirs for conservation would reduce the flood flows v.-hich occur about once in 25 yesrs on the average sufficiently to prevent any contrib- ution to the crest flows of floods in J.2ission Valley originating in the drain- age area below Mission Gorge No. 2 dan site. Such operation v;ould reduce the probable once-in-50-year flood flow- at Old Tovm from 46,600 second-feet to 34,600 second - feet, the probable once- in- 100-year flood flow from 71,600 second- feet at Old Tovm to 55,000 ss2ond-feet, and the r^robable once-in-250year flood flow froa 99,200 second-feet at Old Town to 79,000 second- feet. This vnuld prevent serious flooding and drniage to Mission V-13ey lends except by floods occurring less frequently thsn once in 50 years on the average. However, this condition might create a senss of false security in that area end r-sult in a -27- possible loss of life and e large property drnage should the valley be built up v;ith residences. A reduction in the probable once-in-100-year flood flow at Old Tov.Ti from 55,000 to 52,500 second-fe^t may be accomplished under con- ditions of complete conservation development at almost no additional cost by the inclusion of flood control features in Mission Gorge No. 2 reservoir. A greater degree of flood control may be secured with additional flood control regulation at Mission Gorge No. 2 reservoir at greater cost. Under present conditions, as well as with complete development, the larger flood flows mentioned would flood practically all of the valley floor lands in Mission Valley. To protect these lands a leveed channel would be required. Such a channel running from the mouth of Alvarado Canyon to Presidio Hill, Old Tomi, has been estimated to cost approximately $2,000,000. As the value of the lands subject to inundation has been estimated from the 1935 assessed veluetions to be but $404,000, it does not appear that protection from flood flows in Mission "Valley is justified at present ?Jid will not be justifiec^ until such time as the lands which would be protected increase several times in value. The flood channel designed for the San Diego River from Presidio Hill to Mission Bay would bo a part of a v.lm for the reclamation and develop- ment of the State Park lands bordering on the south shore of Mission Bay, and the adjoining lowlands. The design of a plan for the complete reclamation and development of these lejids v/as not within the province of this investi- gation. The flood regulation of the San Diego River through the Mission Bay area v;hen complete conservation development of the stream basin has been made, may be accomplished at minimum cost by the inclusion of flood cofttrol features in Mission Gorge No. 2 reser-zoir, controlling the probable once- in - 100-year flood at Old Tovm to 52,600 second feet, and the construction of a -28- flood channel from Presidio Hill to Mission Bay with a capacity of 52,600 second-feet. If no flood control features are incorporated in Mission Gorge No. 2 reservoir, and all reservoirs operated for conservation, the cost vjould be but slightly higher, as shown by the follovang table. The flood control channel as designed v/ould carry the 52,600 second- feet of the probable once-in- 100-year flood flow vjith complete conservation development ajid flood control features incorporated in Mission Gorge No. 2 reservoir, with a minimum 4-foot freeboard on the levees. It would carry the flow of 71,600 second-feet which may occur once in 100 years on the average under the existing development v;ith a rainimurri freeboard of 2,4 feet. The flow of 99,200 second-feet, which may occur once in 250 years on the average under present conditions, would pass dcvm the channel with a minimum freeboard of about one-half foot remaining on the levees. This freeboard could be increased to at least 1.5 feet, however, at little if any additional expense by slightly decreasing the width of crovm of the levees and adding the material to the top. COSTS CF FLOOE PROTECTION IN MISSION BAY AHSA With and v.-ithout flood control features at Ivlission Gorge No. 2 reservoir and with San Diego River chajmcl improvement and re- location from Presidio Kill to Mission Bay. : Capacity of : channel with : minimum 4- :foot free- : board on rlevees, in : second- feet Costs Flood control features of J/Lission Gorge No, 2 rusoiToir Channel improvamont and relocation TotpJ. Capital Annual Capitt.l Annual Capital • Annual 52,600 : 55,000 $1,000 tZQO.OO ffa,341,000 (1) : 1,355,000 ei01,800 (1) 102,900 §1,342,000 (1) 1,355,000 $102,100 (1) ^102,900 (1) Values interpolated from Table 50 and Plate XXEX, Chapter VI. ■29- Conclusions. The principal conclusions of this investigation may be summarized as follows: 1. The water supply of the stream basins tributary to San Diego County, excluding the watershed of the Tia Juana River in i.'exico, which can be conserved and utilized under the fullest practicable development, is insufficient in amount to meet the ultimate water requirements for all consumptive uses in the county, 2. Because the water supplies naturally tributary to San Diego County are deficient in eraount to meet the ultimate water require- ments, it is essential that, in the formulation of plans for complete development of the water resources, such plans must be based primarily upon conservation and utilization of water for domestic, municipal or irrigation purposes. All other possible uses :r.ust be necessarily incidental and secondary. 3. The total mean seasonal run-off from stream basins tributary to San Diego County excluding the Tia Juana River watershed in Mexico, is 302,000 acre-feet from which a maxim\am annual safe yield of approximately 160,000 acre- feet may be obtained through the util- ization of existing and potential reservoirs and underground basins. This amount will supply a net area of 125,000 acres with either a municipal or an irrigation supply. Should the irrigation develop- ment and use continue to increase at the same average rate that it has durir^ the past forty years, or since the first major water supply developments were made, until 1965, resulting in an irrigated area of about 75,000 acres, only sufficient local water supplies can be developed to meet this irrigation use and in addition meet -30- municipal and domestic demencfe sufficient to supnort en urban population of not more than 500,000. 4. All present developments in the county of v;p.tor supplies from both surface reservoirs, including El Capitan Reservoir, and underground basins have en estimated annual safe yield of 79,000 acre-feet or approximately one-haJ.f of the total annual safe yield that may be obtaaned from complete development. Taking the county as a v;hole, the present annual safe yield of 79,000 acre-feet is approximately equal to the present use for all consumptive purposes, 5. In order to be assured of en adequate and dependable water supply, future water requirements must be anticipated far enough in advp-nce to permit the construction of surface storage reservoirs to conserve the run-off of the infrequent wet years. It has been estimated that under complete conservation development of the San Diego River, the full safe yield may not be secured until eight years on the average after the storage reservoirs have been completed and put into oper- ation, 6. The relationship between annual rainfall and run-off varies so greatly in different years that the use of precipitation records for any one season for the estimation of run-off for that season gives unreliable results. The most reliable method of estimating available water supplies is through the use of dependable streajn flow measure- ments. Stream flow records should be secured at additional points on San Diego County streains and more complete records obtained at many of the existing stream measurement stations. -31- 7. The laDst econoriic plan for the conplete conservation of the water resources of the San Diego River Basin con^jrises the construction of two additional reservoirs, Sen Vicente and Mission Gorge No, 2 reservoirs with 174,500 acre- feet and 29,200 acre- feet capacity, respectively. The canital costs of the reservoirs with these cap- acities have been estimated to be $5,519,000 for San Vicente reservoir and $2,143,000 for Mission Gorge No. 2 reservoir, or a total capital cost of $8,662,000. 8. The operation of San Vicente and I'iissicn Gorge No, 2 reservoirs with 174,500 and 29,200 acre-feet capacity, respectively, in coordination with existing development, vdll result in a total annual safe yield from the San Diego River Basin of 32,500 acre-feet or an additional annual safe yield of 18,500 acre-feet (16,5 millions of gallons per day) , 9. The San Vicente and Mission Gorge No, 2 reservoirs operated for con- servation only v;ould decrease the probable once-in-250-year flood flow from 99,200 second-feet to 79,000 second-feet at San Diego (Old Town), the probable once-in-100 -year flood flow from 71,500 second- feet to 55,000 second- feet, the probable once-in-50-year flood flov; from 46,600 second-feet to 34,600 second-feet, and the once- in- 25-year flood flow v:ould be decreased so that there would be iio contribution to the crest flow in Mission Valley area from the basin above Mission Gorge, 10. The channel iu^rovenent and relocation of the San Diego River fron Presidio Hill to Mission Bay, vAiich v.ould be a part of the reclama- tion and development of the Mission Bay State Park and the adjoining ■32- Irrids, incy be r.cccnrilished e.t p. nininvun cepitrl cost of cpproxim£.tely $1,340,000, v.'hen cci^plote ccnservction cleYelopnent is r.p.dc in the San Diego River 3&sin, by incorporetin^; flood control features in Mission Gorge !Jo, 2 reservoir, and s:t slightly greater cost if Mission Gorge No, 2 roserv;ir is constructed for conservation only. The chan- nel capacity required with or without the flood control fee.tures in Mission Gorge Ko. 2 reservoir will be 52,600 second- feet or 55,000 second- feet, rospectivsly. 11. The protection of Mission Velley lends subject to iniondetion fron flood flows occurring once in 100 yerrs on the everage is not justi- fied until such tine rs the v?lus of the lands to be protected increases materially. 12. The protection of Tia Juejia River Valley Irnds subject to inundation is not econoniicflly justified with the existing farm lejid values. -33- CHAPTER II WATER SUPPLY An inventory has been made of the water supply of the Pacific slope basins of San Diego County for the 46-year period 18S7 to 1933. The full natxiral run-off has been determined by months for the San Diego River and by seasons for the other principal streams. On the minor streams, where few if any act\ial records were available, only the average seasonal run-off for the period has been calculated. Description of Basins . The topography of San Diego County is characterized by a broad mountain region which on the east descends steeply into broken mountains and desert valleys along the edge of the Great Basin, and on the west has a gradual slope that flattens into a coastal belt of broad, smooth-topped terraces or mesas. The main moxmtain chain, known as the Peninsula Range, extends south- ward to form the backbone of the Lower California peninsula, while to the north it broadens and merges with the San Jacinto Range on the east and the Santa Ana Range on the west, with the ref^ion between occupied by mountains and valleys irregularly dispersed. The topography of the mountain region is complex, and is dissected by valleys axid canyons into more or less isolated mountains, such as the Aqua Tibia mountains, the Palomar mountains, and the San Ysidro mountains at the head of San Luis Rey River, the Volcan mountains at the head of Santa Ysabel Creek, the Cuyaraaca mountains at the head of San Diego and Sweetwater rivers, and the Laguna mountains at the head of Cottonwood Creek. -34- North from La Jolla, the coastal belt terminates in a line of sea cliffs which run alnost unbroken between the flat, marshy valleys at the mouths of the several streams. South from La Jolla the coast line is characterized by peninsulas, bays, sandy beaches and tidal flats. The terraces or mesas of this belt range in height from 20 to 1200 feet above sea level and extend from the international boundary to the San Luis Rey River, north of which the staep, rounded San Onofre Hills replace them. The principal streams in San Diego County rise near the divide and flow in general in a southwesterly direction to the Pacific Ocean. In the mountain region they have cut deep, narrow canyons which occasionally widen into highland valleys. Across the coastal belt the streams have eroded much broader valleys. The major valleys consist of more or less distinct parts, being narrow where the streams have cut through resistant rocks, and wider through the softer formations. The minor streams are less deeply entrenched and have for the most part cut only narrow canyons. In addition to the major stream valleys, there are many broad valleys or basins scattered from the coastal belt to the top of the divide. Characteristic of these basins ara El Cajon, Escondido, Santa Maria and Warner valleys. Of the entire land area of San Diego County 2973 square miles or 70 per cent lie on the Pacific slope and 1248 square miles or 30 per cent on the eastern slope. The principal streams whose drainage basins lie entirely or partly in San Diego County are the Santa Margarita, San Luis Roy, San Diegiiito, San Diego, Swo£tT7ater, Otay and Tia Juana rivers. The drainage basins of these streams are shown on Plato I, 'Trincipal Drainage Basins and precipitation and Stream Gaging Stations in San Diego County," together with the- boundaries of sub-basins and precipitation and stream gaging stations. ''Torth of the Santa Margarita River, there are several minor streams from San Mateo Creek on the north to Aliso Canyon on tho south whose basins lie partly in San Diego County. South of the -35- PLATF. I LEGEND ®: Active Stream qaqinq stations • Discontinued stream qaqinq stations o Precipitation stations Boundaries of principal drainaqe basins ---Boundaries of sub-basins PRINCIPAL DRAINAGE BASINS AND :CIPITAT10N AND STREAM GAGING STATIONS IN SAN DIEGO COUNTY SCALE or MILES 12 PLATE I Santa Margarita Rivor, thore are many minor streams draining the sea-.7P.rd slope of the most westerly ridgo of the Peninsula Range ^hosc basins lie between those of the principal strjoins. The more important of theso minor basins ire those of Vista, San Marcos, and Escondido creeks, Los Penasquitos, Rose -ind Las Chollas canyons. The Santa Margarita River is formed by the junction of Temecula and lAu-rieta creeks near the to-.7a of Temecula. From this point the stream flows about 27 miles in a southTrtstw-rly direction to enter the P-^.cific Ocean 3 miles northT/est of Oce inside. The headwaters of Temecula Creek originate in the moimtains northeasterly from Oak Grove Valley. From this v?.lley Temecula Creek flo77s northwesterly 23 miles to its junction v/ith Llurrieta Creek. There are several small valleys in its drainage basin but the country is mainly rough and broken. Some of its tributaries drain tho north slope of Palomar Mountain which rises to an elevation of over 6,000 feet above sea level. Murrieta Creek has a broad flat drainage basin and contributes very little water to the Santa Margarita River except in seasons of exceptionally heavy rainfall. It rises near the divide between the Santa Margarita River basin and that of Lake Slsinore to the north and flows in a southeasterly direction about 10 miles to join Temecula Creek. The eastern tributaries of Murrieta Creek drain a broad, flat plain broken only by isolated hills, althovigh T-acalota Creek rises on the slopes of Red Mountain at an elevation of over 4,500 feet above sea level. The watershed of the Santa Margarita River above the gaging station at Ysidora has an area of 743 sauare miles of which about 195 square miles are in San Diego County and about 543 square miles are in Riverside County. The San Luis Rey River rises at the upper end of the Warner Valley and flows southwesterly across the valley into the Henshaw Reservoir. Several smaller tributaries flow into tlie reservoir. Below the Henshaw Dam, the river has cut a steep, narrow canyon which skirts the foot of palomsir Mountain. -36- Santa Margarita Rivor, there are many minor streams draining tho seaw>-ird slope of the most westerly ridgo of the Peninsula Range vrhosc basins lie between those of the principal streams. Tho more iiaportant of theso minor basins ?.ra those of Vista, San Marcos, and Escondido creeks, Los Ponasquitos, Rose and Las Chollas canyons. The Santa Margarita Rivor is formed by the junction of Temocula and Murrieta creeks near the town oi' Temecula. From this point tho stream flows about 27 miles in a south.7est.;rly direction to &nter tho P-^^cific Ocean 3 miles north-.7est of Occinside. The headwaters of Tomecula Creek originate in the mountains northeasterly from 0::^k Grove Valley. From this v"lloy Temocula Creek floT7s northwesterly 23 miles to its junction -Jith Liurrieta Creek. There are several small valleys in its drainage basin but tho country is mainly rough and broken. Some of its tributaries drain tho north slope of Palomar Mountain which rises to an elevation of over 6,000 feet above sea level. Murrieta Creek has a broad flat drainage basin and contributes very little water to the Santa Margarita River except in seasons of exceptionally heavy rainfall. It rises near the divide between the Santa Margarita River basin and that of Lake Elsinore to the north and flows in a southeasterly direction about 10 miles to join Temecula Creek. The eastern tributaries of Murrieta Creek drain a broad, flat plain broken only by isolated hills, although T-acalota Creek rises on the slopes of Red Mountain at an elevation of over 4,500 feet above sea level. The watershed of the Santa Margarita River above the gaging station at Ysidora has an area of 743 square miles of which about 195 square miles are in San Diego County and about 548 square miles are in Riverside County. The San Luis Rey River rises at the upper end of the Warner Valley and flows southwesterly across the valley into the Henshaw Reservoir, Several smaller tributaries flow into the reservoir. Below the Henshaw Dam, the river has cut a steep, narrow canyon which skirts the foot of Palomar Mountain. -36- After emerging from the canyon near Rincon, it traverses a series of valleys of varying widths until it flovjs into the ocean at the city of Oceanside. Moosa and Keyes canyons are the principal tributary basins below the canyon. The highast elevations in the basin are on Pr'.loinar and Hot Springs mountains, both of which rise to elevations of over 6,000 feet above sea level. The watershed above Oceanside has an area of 565 square miles, all but 1.5 square miles being in San Diego County. The drainage basin is about 56 miles long and has an average width of 10 miles. Escondido Creek rises on the slopes of La.s Lomas Muertas, a small range to the northeastward of Escondido, at an elevation of about 2,300 feet. The drainage basin is a minor one and does not reach the crest of the divide. After crossing the wide valley around the City ef Escondido, the stream flows through a canyon south of Mt. Whitney, crosses the coastal belt and enters the Pacific Ocean -bout 3 miles south of the toiTn of Encinitas. The watershed above the San Eli jo dam site has an area of 57 square miles. The San Bieguito River, known as Santa Ysabel Creek from its source on the west slope of Volcan Ivlo^-mtain to the San Pasqual Valley, flows south- westerly and enters the Pacific Ocean about a mile north of Del f'ar. Its drainage basin lies entirely in San Diogo County, south of and adjacent to the San Luis Rey River and Escondido Creek bisins. The principal tributaries are Black Canyon, Tcmescal, Santa Maria and Guejito creeks. The upper drainage basin of Santa Ysabel Creek is vjry steep and rugged, reaching elevations of over 5,000 feet in the Volcan Tiountains. Below San Pasqual Valley, the San Dieguito River flo"s through a narrow canyon in :;hich Hodges Dam is constructed. Below the canyon, the San Dieguito River flo'.7s to the ocean through a valley cut in the coastal terrace. The watershed above the former gaging station near Del Mar has an area of 327 square .nilos and is about 38 miles long with an average width of about 9 miles. -37- Tho San Diego Rivor rises near Julian and flows in a southwesterly direction to discharge; into tho Pacific Ocean through Mission Bay. Cedar and Boulder creeks join the main river a short distance above the Diverting D^Jii. Boulder Creek makes a precipitous descent from the Cuyamaca Reservoir which lies at an elevation of 4,600 feet abovo sja level. Abovj this reservoir, tho highest elevations in the basin are reached on the slopes of Cuyamaca Peak, which rises to an elevation of over 6,500 feet above sea level. The South Fork of the San Diego River enters the river from the east about six miles below the Diverting Dam and Chocolate Creek enters the river from the south about eight miles below the Diverting Dam. Just below the mouth of Chocolate Creek, the city of San Hiego has recently completed the El Capitan Dam. About two miles below El Capitan Dam, the San Diego River emerges from a canyon into the upper San Diego River Valley which it traverses for about twelve miles to luission Gorge. Los Coches and forester creeks enter the San Diego River from the south and San Vicente Creek from the north in the valley. Forester Creek in reaching the San Diego River traverses the broad El Cajon Valley. San Vicente Creek en^erges from a narrow canyon into a branch valley about three miles above its junction with the San Diego River. In the Mission Gorge, the San Diego River has cut through an igneous dike similar to that on the San Dieguito River at Hodges Dam. This gorge derives its name from the Mission Dam builL by the Franciscan Fathers in the early part of the ninet-senth century. This dam is still standinr with the exception of a short section at the left abufeient. Between the Mission Gorge and its mouth in Mission Bay, the San Diego River traverses the Mission Valley, which it has cut in the coastal mesa. The ratershed above Old Town has an area of 435 square miles. Its Ijngth is about 42 miles and its average width about 10 miles. The Sweetwater Rivur rises on the southeastern slopes of Cuyamaca -38- Mountain, flows south and then southwesterly, and discharges into San Diego Bay south of National City. The topography of this basin is not as rough as that of the San Diego River Basin although the mountains and foothills extend to within three or four miles of the shore line of San Diego Bay. Near the edge of the foothills, the Svjeotwater Dam has been constructed forming the Sweetwater Reservoir. Above this reservoir is a valley "hich extends eight miles eastward. Bolor? the Sv/eotwater Dam, the river runs through the Sweet- water Valley which it has cut in the coastal terrace. The watershed above the Sweetwater Dom has an area of 131 square miles :.'ith a length of about 36 miles and an average v/idth of five miles. The Otay River drr.ins a basin on the lower western slope, lying between the Sweetwater River basin on the north and that of the Tia Juana River on the east and south. The principal tributaries are Dulzura, Jnmul and Proctor Valley creeks. Upper Otay Reservoir is located on Proctor Valley Creek. From the Lower Otay Reservoir, situated on the edge of the foothills, the Otay River runs westward through a valley cut in the Otay Mesa and discharges into the extreme southern end of San Diego Bay. Although well known because of Upper and Lower Otay reservoirs, the basin of the Otay River should perhaps be classed as one of the minor rather than one of the principal driinage basins of San Diego County as this basin does not reach the crest of the ronge but drains only the seaward slope of the most westerly of the ridges. The highest elevations in this watershed are reached at Lyons Peak and Otay Mountain which both reach elevations of over 3,500 feet above sea level. The watershed above Lower Otay Reservoir is nearly lialf as wide as it is long and has an area of 99 square miles. Its length is about 15 miles and its average width is 7 miles. The Tia Juana River proper, comprising that part of the main stream below Rodriguez Dam, is about seventeen miles long and flows in a northwesterly direction, entering United States from Mexico near the town of San Ysidro and -39- emptying into the Pacific Ocean about two miles north of the international boundary line. Cottonvrood Creek, the principal tributary draining practically all of that part of the basin lying in the United States, rises on the slopes of Laguna Mountain which reaches an elevation of over 6,000 feet above sea level. It flows in a general southwesterly direction and joins the main stream in Mexico about four miles above the international boundarj'- line. The drainage basin of Cottonwood Creek is roijgh, although there are several small valleys at elevations of over 3,000 feet. Its principal tributaries are Pine Valley Creek and the Hio de Tecate. Pine Valley Creek rises on the west slope of Laguna Mountain and its watershed is entirely within the United States. The Rio de Tecate basin lies on both sides of the international boundary. The principal tributary of Rio de Tecate is Campo Creek whose watershed is almost entirely within the United States. Cottonwood and Campo Creeks are the most southerly streams in San Diego Co'onty. The watershed of the Rio Las Palmas, the main stream above Rodriguez Dam, is entirely within Mexico except for an area of about eleven square miles between Campo and Jacumba. Its tributaries, the Arroyo de Calabazas and the Arroyo ie la Cienega, join to form the main stream in the Cancio reservoir site. These tributaries drain the extreme southeastern part of the watershed. The Arroyo Seco enters from the east near the head of the large valley known as Valle de las Palmas. Arroyo Matanuco joins the Tia Juana River a few hundred feet below Rodriguez Dam. The Tia Juana River flows through a wide, flat valley after entering the United States, with a low terrace to the north. In times of extreme flood it has discheurged part of its waters through a low saddle near Nestor into San Diego Bay. The drainage basin of the Tia Juana River is about 76 miles long and has an average width of 22 miles. The aroa of the 7/atershed above the bridee near Nestor in San Diego County is 1,658 square miles, of -40- ll f 1- ass t-iAmQffi ^toHcg<-4 Ain^t^o 9*r •roN'nA c^otNCD*o t>oioo>o va •f F) rt n rt e J a o <» c- Qt n 3 »S 5 I 8 8 «0 M » ■^■■"s as Bg 3§ 2g I SiSp.sS 3 ♦ ♦ M rt n lo* M* n M ri n" 888888 IS8SS S88S8 ) Ot 9t r4 -^ i§ § s§i§§§§ § 88 ess lO •¥ to Q «> O CM if> CD to to V 10 Ol lO £ OS " si k « ** q •a ad ri ♦> 1 a^^ 2 "a 1 §,, •3 SS 23 I _ e > a 5 1 a a - i = a g 3 a ►■ ja ^ » S jtf P a D s d . "* ^ E ^ ■ O O 3 • I °a I 3 Si -< t. (- 3 I d U » « O I t< q ;* > ui * 3 e ^ ^ ^ ^ > ** ii: Q ec i n •< u 3 i ■> a 9 o a -r* ^ a > ^*] • -a e ^ 0) p a , o a 4> o J3 O 9 M « (9 > (3 ^ e t 3 fl B O S UOOQM BQd ' 'O e n 3 « o s -H >* a e [> a u a Aa a fi : j3 to ► ^ t» . a S Q m 3 S 39 n -4 S 3 CO CO o ii -4 .. /• Q 3 I I ° I I * o 31 « a 3 :>. 3° S"! o a • a • n o j3 e B Q i Q K n A (D O « f> k J3 »> X> l> O O O q A b A L< A ■^ « C ^ ^ t< ^ M ^ h « s a: « s • » t» »■ o: « X a: -4 |4 (1 M IS V B S « *> 4^ ** ** *1 ^ C o CO n • 6 a « fr 3 Q ♦« a o I 0.0 ; ^ > • » lu O a D O B *> q a q 4* q o -3 o *> On o 0. ijsi f * : 'O • ' -M P u I « b 1* I 5o HO q ^ ** o o ** c • « • N • % 23; 5 I 3 2 s s • s X sa s s u>^cHo Sot C3 ^ fi CMr4r^OMOn CMS n« io-taic-otinvin^vi 3SS CD a> H c^ ^ « O » n o n N n O 9t ^ C- IS O o> n o o A (M (O « O -4 O 0* ■o n n M (O N CM CM N ^ n n gi N O O Q O O O c tO lO <0 lO 10 Q C n 91 ot ot ot n ^ 800 00 OOQOOC^iQlQOO 00 on lOoioiOiOinMN C' to St ntO CMM^iH^rH 00c 9S^ 8S 33|i S|SS 88 n o n o rt o cmScmocmo. COu'jCO<0• ^ -a 3 o 3 > « ,-• O rH 3 ■ p o (4 d e I -H ^ 3 1 ■^ a '-• a ^ a ~ - - a c « e < bu c >:) > t4 -H ^ > B O '4 !• o .o o a < > Jd Jd ^ « I I > t, > I X n .400 3 . ^ d '' o " - J I4 U (• U l< :£ t U fl (4 O U ■ 'Id 0^0^01: 19 a a a < »> *> t' a *; q to q '0 q '^ c to 01 0000 » c^ O ^ O) n ri lO > lO *o to a; ■r4 >.a: >. c: X » V -M a. X >i h >tX. 0^0 q -* 3 :-■ a-" 3S-' ! 1 3" S" 3° a _ I q 14 i s a di a ♦> a g 00 -I *> a -o M 30 3 0-0 « 5 ^ . * q a S q O0Q0VVVVV :j0cQ0q0a0O e«* o*j •£ 0^*0 >a:^x^x»x^ X >.x >»« >»2 >»2 o >,x >va: >ta >.« >• a o 9 -^K OX0X 0XMX «'03m30q030 o_, gj jj S-" 3-' ;j I q a u f* s a q I" £Sa !3 a q o » vj 0^0 ■ ja Ji< A h e u V J< »4 C 0000 •< o ( q < O M * 3^5 2g -a -9 ^ *• ■« •«3£ : 90 O -2 q Tj -4 b q .^ I QCH (4 ^ 3 s >> »4 '^ u 00 t 3| I I I o-o ■0 5 d ■SI I I » 3 : ■si" 3 9 ° £ 3: 0001000 * n 0. t* koa m m IB » a M ** f** "OQ «a0 Aq w « £ isl e 9 Jii£« O 1333 _ 10 n •5g3iS 2 "* £ * • .* jgp Jtf O Jl o J< 0^0 £ • ESS t O J« O o a • rH ffl O -4 o (• S"|S13 o >• « S >• >* O 3 5838133 en t- CO g en - - _ E=4 _ .. 09)C10«00q0 ^ 0«*n0S0 Q .iiii.l.i . ^ tt 3 a u m h m JK O •• 000-<30-M0^ ef* X -t p- a ^ X ► O Jit f -4 -4 ^ fl B w • *1 S -^-*»4-40-»»0** o »^S25 ilaf 2 5 ><0-4^ g0::) ma** illSi^ 3^35^ which 461 square miles are in the United States. The aroa in square miles and the maximum, minimum and average elevations of the drainage basins and sub-basins of the principal streams in San Diego County are shown in Table 1. Precipitation , Many records of the occurrence and amount of precipitation at different points in San Diego County for varying periods of record are avail- able. The locations and elevations of the precipitation gaging stations to- gether with the period of record available are listed in Table 2, and the locations are shown on Plate I. About 20 per cent of these records kept by the United States Weather Bureau or cooperative agents and published in Weather Bureau bulletins are not given in this report. The other records, kept by local civic agencies, public utilities, private corporations and individuals, hitherto unpublished, or published in bulletins now out of print, are given in monthly and seasonal form, together with the authority compiling the data in Appendix "B". Although the United States Weather Bureau publishes a table of precipitation at San Diego beginning in 1850 and active at the present time, the early years of this table are a compilation of records kept at various points in the vicinity of San Diego and the published data is not a continuous record of one gage in an unchanged location. Six other records were commenced in the decade 1870-1880 but altho several of these cover periods of over 30 years and are active at the present time none of them are unbroken. Seven records were begun in the decade 1380-1390, two of which, Sweetwater Dam, 1888, and Cuyamaca Dam, 1837, are unbroken and active today. Of tho 138 records listed in Table 2, 18 are over 30 years, 33 are ovjt 20 years and 69 are over 10 years in length. 51 are known to bo active at the present time. The characteristics of tho precipitation of the Pacific slope of San Diego County are illustrated by the data shown in Tabl^ 3. In this table -42- *rfN^fV ^N(S»'\j» ^ j*j» v^j» j9 jt j» t^tn^ • •• • •• • •• * « t> • • ». «j A V. <• 3 ii: I • 4 f^H^K2"*SS'"SR3»--a««8??'"a"as~il 'i^'tSS^Sf J ^ ^ 2 A o a I 11^1 DSLie«!:RKSSSSMS'g&S£&RS^S^lR«SSS8SS&S»«S8SS3 3a:?5SSSSS8S SiSTt»«5S5S,f Si is: O 9 -M r: — >. r >■ . K-. rl^ tn (7^vo t^ t^-*^ r tr o^ o ^ cr* o^;:; -; ;:; ;n :^ iZj 2 £; C S^ i5 ^ o o O O 5 o o ifis ll] " ■: £ .: E fe ; fgS >» c a c ti illlls I ss p ^ fc. o O S S ^ .s fe 9 9 A ^ £ ^ (3 £ £ a — • s ^ O 'J « V «-'— -ii' 5 9 tj ,: £ j ^ s I « I # <^ .'; <^ .: e .a d I > o ■II 3« I :. c k k t. -• ,>.-vo,-»» •"'^2SaS>3i-ar73ffS!ia?:-3S^KrSf?°iAi».F^R *.K° SS3S5^S'i?^"5'?>l?.»f*»*'*«KRSS3a©S»«S the maximaii, minimiun and mean seasonal precipitation and the monthly distribution in per cent of seasonal for the period 1908 to 1933 are shoun for nine stations in San Diego County. The stations iwiy be located on Plate I by use of the index number shorn in the table. For three stations, Warner Springs, Cuyamaca Dam and San Diego, the percentage of precipitation produced by each different storm type in the period 1928 to 1933 is given. The stations included in this table are typical of conditions from the coast to the crest of the divide and from Orange County to the Mexican border. The mean seasonal precipitation varies from a minimum of about 10 inches at the coast to a maximum of about 40 inches in the higher portions of the divide. The variations from season to season are extreme, the precipitation in maxi- mum seasons may be viell over twice and in minimum seasons may fall to approxi- mately one-half the mean seasonal rainfall. The storms which bring precipitation to San Diego County have been segregated into four types according to their source,- North Pacific, South pacific, Interior and Mexican.* The North Pacific storms include all those which approach the Pacific Coast north of San. Francisco. These storms origi- nate off the coast of Alaska and travel in an easterly direction across the North American continent. During the winter months their storm track swings southward and from November to May southern California lies within their pre- cipitation area. The precipitation yield from North pacific storms, approxi- mately 43 per cant of the seasonal total, varies less from year to year than that of the other types. The South Pacific storms include all those which approach the Pacific Coast south of San Francisco and north of the Tropic of Cancer. These storms, producing about 19 per cent of the total precipitation, are irregular in *"Storm Types and Resultant Precipitation in the S^in Dieco, California, Area,"- Dean Blake, Monthly Weather Review, Volume 61, August 1933. -44- . O (ti o to o r— Lr^ CO (-1 LO CJ to r-t ONV-O i • ' • vD i-H r^ r^ oj CM CM i-l CT^ CTN 00 CM Ci OJ J- to vj) J- 1^ r-H to OJ V£) CM CM r^ I o c u o 60 lO i-H '^ to I^ r-l a '-* t-- CJ rH CM " r-l o o LC> o CM CTM^ rH J- CJ CO (-1 rO rH I • I ♦ rH 60 CM O r— CM CM r-l i-l CTi C7> r-H r-i r^ CM 1~0 LO OJ rH CM CM OJ r^ 60 I • I • ■H 60 J- CO r~- CM I^ CM a~\ en vx) U3 60 C3^ CJ I — LPv t^ r^ CM r-4 CJ rH lO I • I • r-l J- J- r-r^ oj CM rj CT\ CTv isD O CM I — C7^ CO vx> CM LPi r-l CM i-< I • I • iH o 60 cn bO CM^ rH r-l ro en o 60 -=f r-l r^ r^ o cTi J- J- OJ CJ ,-:t r^ CM Vi3 O CM OJ i-^ OJ r^ r-l CMV^ O tn CM C7^ . cr\ o cnj- o § o CM VX) r-t M 60 cn CTM-~-) r-l • rH O 1^ cn LOi CT r<^ CM OJ OJ (T\^ 60 r-l • ♦ C\S O r-l o rH LPv^ Cn LO r-l •-3 CJN r^ I — Jt O VX) r<-\ I^V£> OJ LPi ^— J- r-H r-l LC^u^vx) r-i en J- er r^ o r-t OJ rH r-l rHinr-HCniHrUr-lt-- LO^ r-l h^ OOr-lLrvr~-ftOCM60J-C<: I'^O rH OJ rH r-l MDVX) r«^rHVX) I — rH O l<\KO r— ^ • ••••••••••• J- OJ r-l J- \X) J- O CTv J- t K> O r-l OJ r-l rH rHVXI>.D r^lTNCM 60t^LrirH rH lO o o o ir% 1^ ^- cTvcniPiCJ"^^ o K^ CTNVvO rH ;d- K^ 00 rH en t^ r^VX) I-l rH rH LOVX) UD CTv CTN^ CT^^ O 1^ U^^ O r-4 rH 60 >X) LfA 60 LC^-lt o o rH Lpv t-^ r-- cn CT^ J- cn^ o OJ VX) 60 en 60 I — cn>x) r— o J- -if OOO^VD^X)r^O^^ CT^ J- O rH OJ CM rH r^lTMrvl — CO to C3>CM OJVX) rH^ r<^^ OJ J- u^vX) CO 60 r^ r— ^ O VX) VX) O r~- LTN J- rH O U^ O rH LO rHr^cjuMrM^ojoj-eor^o r-l OJ OJ rH OOvjenrHI-^rHCOOJrHLTNKMr^ • •••••••••9 O O OJ-UDVD h-OJ r^vXJ OJ O rH OJ OJ rH o •H > (1) 0) +> a! •♦J c o ^^ CD 0) •H o nS o o ^ -H o « Q) CS 0) 3 o (3 p, d 3 O 1-3 Pn, S «< S »-3 0) a o •H ^« 0) o +> -H «! -fJ E nJ •rH 4i W -H O ft ^^ -H & " P, 0) a! ti it (0 0) V « ■H OJ -T^ Q) § > •iH 01 « o a ■rH o = « • cn ■!-> OT ivx> O) -45- I 1 ' occurrence and vary widely in production from season to season. They may occur at any time from November to March and often bring warm and heavy rains. The Interior storms, errtitic in movement, may occur at any time of the year, but are most frequent during the spring months. They produce about 30 per cent of the seasonal total. The Mexican storms occur only in the fall months from August to November. They are extremely erratic in movement. Altho they seldom cross the mountains to the coast, they often cause heavy rains of the cloudburst type and account for an appreciable portion of the seasonal precipi- tation in the mountain areas. The cloudburst of August 12, 1391, at Cainpo, in which 11.50 inches of rain are said to have fallen in 80 minutes, is an extreme example of this type of storm. Fortunately falls of this intensity are rare. The monthly distributions shown in Table 3 indicate that the heaviest precipitition may be expected in January and February and that over 70 per cent of the seasonal total may be expected to occur during the four months from Decombur to L'p.rch inclusive. In exceptional seasons the fall in one month may be well in excoss of the mean seasonal precipitation. The precipitation usually occurs in the form of rr.infall but there are some snows practically every year in the higher mountain areas. At Warner Springs, elevation 3,155, about 4 per cent and at Cxiyamaca, elevation 4,677, about 10 per cent of the total precipitation may be expected to occur in the form of snow. This snow seldom remains on the ground for more than a few days and unless carried off by a vrarm rain usually disappears without any marked effect on the flow of the streams. The variation of mean seasonal precipitation from the coast to the crest of the divide is shown graphically on Plate II, "Variation of Precipi- tation with Elevation in San Diego River Drainage Basin." The data on which this analysis is based are given in Table 4 end include the available records of precipitation at points in or near to the San Diego River Basin. It will -46- TABLE k VARIATION OF FRECIPITATIOII WITH ELEVATION IN THE SAN DIEGO RIVER DRAINAGE 3ASIN : Precipitation station : l+S-year mean ; seasonal : Elevation, : Length : of : iNumlier : { on : Name : precinitation ; in feet , : ac tual : ; Plate I : 1387-1933, : U.S.G.S. : record, : in inches : datum : in years : ; 69 ': San Diego : 9.gU .' 87 :' 1+6 ': : 73 : Sweetwater Dam ; 10.99 : 310 : 1+5 : : 7h : Choi las Heights : 11. gi : 370 : 19 : : 76 : La Mesa : 12.18 : 550 : 6 : gU El Cajcn Valley : 12. UO : 670 : 31 : : 82 : El Cajon No. 2 : 12.81 : U80 : 6 : : S2 : El Cajon No. 1 : 12.82 : USO : 9 : : 75 : Murray Dam : 12.83 500 : 20 : : 89 : Lakeside 13. 18 500 6 : : 6U : Mira-^iar 13.56 660 27 : : 90 : Los Coches 13.97 71c : ^F • : S3 : El Cajon No. 3 13.99 560 31+ : : 81 : Grossmont 1U.3I+ 61+0 33 : : S7 Los Padres Ranch 15.33 1+90 13 : : 91 Chocolate 16.57 760 l>h : : 96 Diverting Dam 17. 08 8l+0 3U : : 52 Ramcna (Sentinel) 18.21 lUl+C 20 : : 51 P.amona (Verlaque) 18.7s ll+l+O 20 : : 91+ WilloTJS 20.69 2300 19 : : ^3 Rose Glen : 22.65 2300 5 : : 103 Hurlb^jirds Ranch : 2U.58 3U5C 6 : : 109 Descanso 2U.98 : 3350 12 : : 39 Santa Ysahel Ranch 25,19 : 3000 : lU : : 1+1 : Witch Creek : 26.02 : 2800 7 : : ho Santa Ysabel Store : 26.06 : 2983 5 : : 111 Descanso Ranger Station : 27.07 : 3UOO : 3 : 6 : : 99 Schilling : 27.51 1+5 50 : 97 : Boulder Creek : 30.91 2990 : 3 : : 101 : Julian : 31.31 : 1+222 32 : 29 : Volcan Mountain : 31.9^ : 1+800 12 : : 100 : Pine Hills Hotel : 33.55 : 1+lCO : 1+677 3 : 1+6 : : 98 : Cuyamaca Dam : 3S.9S -47- PLATE n 1 , o o o o o o 8 o o o o oo °o p o o O o o o o o o o o o o o o o o o en ££61-^881 S9L|Dui ui uoueiidpajd leuoseas ueaiAj E CO (D .CD o 03 O > o ^ o o o g u _l U I z o z o < CD LJ O < z < Q a: UJ o UJ > cc a: CL O U. o O Ld Q < CO be noted that although the dnt-^ ostiblish i very definite trend of increasing precipitation uith elovition, the ictual precipitation at "Jiy given elevation ma7 vary by as much as 20 per cent from a mean value. These variations are probably the result of local topographic features such as protecting ridges or peaks V7hich cause eddies in the wind directions. Relation of Run-off and Precipitation . The full natural run-off of the San Diego River at Mission Ck)rge and the average of the recorded precipitation at Grossmont and Cuyamaca for each year since 1899 arranged in the order of magnitude of the precipitation are listed in Table 5 and are shoi:?n graphically on Plate III, "Average Precipi- tation at Cuyamaca and Grossmont in Comparison with Full Natural Flow of San Diego River." Although this presentation of the data shows a definite de- crease in the amount of run-off with a decrease in the amount of precipitation, it also shows that the variation in the relationship for individual years is so large that the use of the precipitation of any one season for the estimation of the run-off of that season would be unreliable without considerable modification. The major portion of the run-off of the San Diego County streams comes from the mountain areas. The underlying roc'c of these mountains is granitic and easily weathered. Disintegration in places has reached depths as great as 100 feet below the surface. The soils are sandy and the absorption of rainfall is rapid and large in amount. Consequently, surface riin-off occurs only when the rate of precipitation is in exc^jss of a high percolation rate or when the large storage capacity of both surface and sub-soils has been exceeded. A small portion of the water absorbed drains out immediately after the rain ceases but a much larger part remains in the ground and is either used up in support of plant life or drains out over a period of several years through springs and other outlets. The effect of the absorptive capacity of the soils ■48- TABLE 5 AVERAGE PIffiCIPIT.VTION AT CUYAMACA AND GROSSMOOT Irl COl.'lPAKISON ^ITH FULL NATLTIAL FLOW OF SAN DI3G0 RIV2R Seasonal rainfall , : Seasonal rxia- off, : : Season : in inches at Mission Gorr's : Ouyamaca : Grossmont : Mean : Acre-i-eet : Inches : : 1926-27 : 6U.C0 : 23.71 ": U3.86 : 185 ,0^0 : 9.23 ': : 1921-22 : 59.5s : 25.77 : U2.68 : 201 ,530 : 10.05 : : 191^15 : 55.79 : 26.01 : i+0.90 : 108 ,250 : 5.1+0 : : 1915-16 : 57. S7 : 20. S3 : 39.35 : 352,030 : 17.55 : : I90U-O5 : 57.79 : 19.59 : 38.69 : 50, 37^^ : 2.51 : : 1905-06 : 56.3s : 16.68 : 36.53 : 111 ,U70 : 5.56 : : 1931-32 : 53.58 : 19.36 : 36. U7 -. 102,11+0 : 5.09 : : 1906-07 : UU.9I : Ib.lU : 30.52 t 71 .820 : 3.53 : : 190g-09 : U5.65 : 13.28 : 29.76 : 58 ,100 : 2.90 : : 1925-26 : 37.19 : 21.86 : 29.52 • 36,120 : 1.80 : : 1929-30 : ^1.37 : 16.28 : 28.82 19,160 : 0.96 : : 190001 : U2.gl : 13.68 : 28. 2U S ,b50 O.U3 : : 1916-17 : 39.68 : 16.00 : 27.38 Uc ,600 2.02 : : 1919-20 : 38.97 • IS.2I+ . 27.6c k2 ,500 2.12 : : 1932-33 39.87 1^.39 • 27.13 26 ,900 I.3I+ : : 1913-1^ 3^.82 15.53 25. 18 25 ,580 1.28 : : 1902-03 36.59 13.17 2U.Sg 15 .370 0.77 : : 1922-23 33.11 11.29 24. 7C 22,310 1.11 : : 1909-10 33.UU 13.9^ 23.69 33 .670 1.6s : : 1910-11 32.15 1U.34 23.50 : 19 .730 0.93 : : 192^25 36.10 10.70 23.1+0 8 ,790 : O.UU : : I92S-29 35.^3 11.00 : 23.22 15 ,200 : 0.76 : : 1911-12 31. 83 • lU.lS 23.03 : 23.270 : 1.16 : : 1901-02 • 35.93 : S,9S . 22.1+8 : 7 .500 : 0.37 : : 1917-lS : 29.^6 : 12.72 ■ 21.09 30 ,990 : 1.55 : : 1907-03 : 30.35 : 11.75 : 21.05 : 2^,300 : 1.21 : : 0.1^9 : : OM : : 1930-31 : 27.05 : 1U.O9 : 20.57 : 9,77c : I923-2I+ : 29.39 : 9.05 : 19.87 : 8, 77c : 1912-13 : 31.03 : 7.78 : 19.1+0 : 10 ,600 : 0.53 : : 1920-21 : 27.73 : 10. U4 : 19.08 : 7 ,090 : 0.35 : : O.5U : : I9IS-I9 : 27.91+ : 9.66 : 18.30 : 10,330 : 139^00 : I927-2S : 23.79 : 21. U3 : 7.60 : 10.31 : IS. 20 : 1^.37 : 980 : 11 ,900 : C . 05 : 0.59 : : 0.06 : : 1903-OU : 23.53 : 5.33 : 1U.U3 : 1 ,270 •49- PLATE m k\\\V\W\\\\\VK^ »0€' -gOS' kVWVWVVVWWWW^ ^^^^^^ 8Z6I-Z.Z6I 0061-6681 KWWVWVWWWV^?^ GI5I-8I6I k\V\V\\\V\\vk\\\\\^:^^ IZ6I-0Z6I kV\\V\\V\^VV\W\\\\\\\V^ ei6l-2l6l |\\\\\\V\VV\\\x\\\\^^^ «61-CZ6I kW\VVvW\V\^^;^^ 8061-^061 bm\vv^v\\\\vvv\\\\\\\\^ 8I6I-ZI6I K\4\\V\\\VVV\\\\W Z06I-106I kVVVV\\V\VV\\\\\\<.\\\\\VK\^^^^^ ^V\VV\\\\\\\V\\\\<\\\\\\V\^^^^^ 6Z6t-9Z6l SZ6I-VZ6I lk\\\^\\V\\\\\\\\V\^^^^ 0161-6061 ^\\\\\\\\\\W^\\\\\\^^^^^ 0Z6I-6I6I 1061 -006( 9ZS-5Z6I t\\\V\\\\\\\\VV\\\V\\\^^^^^^ ^\\\\\\\\\VV^VVVk \\\\\\\^^^^^ tk\\\\\\\\\\v^<\v^^^^^ K\\\\\\\\\\\\VVVV\VV \\\^^^^^^ 6061-8061 1061-9061 zeei-icei 906I-S06I 9061 ¥061 ^^^^^ 9I6I-SI6I ^IZZ6I-IZ6I iZ61-926l K\\\\\\\\\\\\\V\V\^ ^^^^^^^ k\\\\\\\\\\\\\\\\\\v v\vv^v^^^^^ k\\\\\W\\\\\\\\\\\k\^^^^^^^ o 5 o o M saqoui ui q+dgQ I- Z o o O u > a: 9 o < Id -> o O «" o Z ^ O z o u CC O. liJ o UJ z I < cr D Z o •s. o u c .2 ♦- .9- o 1 1 o o IQ i; 0) o to m ^ on the run-off from rainfall is T7ell shown by a comparison of the run-offs of the seasons of 1914-15 and 1915-16. In these two seasons, although the total seasonal precipitation V7as about the same, the seasonal run-off of 1915-16 was over three times as largo as that of the season 1914-15. The maximum monthly- precipitation in the season 1915-16, hoT/evor, was over 60 per cent of the seasonal total, while in the season 1914-15 it V7as only about 24 per cent of the total for that season. The effect of the storage and later release of ground water is shov/n by a comparison of the seasonal run-offs of the txio seasona 1903-04 and 1927-28. In the season of 1903-04 the total seasonal precipitation -.vas about nine-tenths that of 1927-28. The run-off, hov/ever, Tvas only about 10 per cent as large as that of the season 1927-28 which had been preceded by the extremely wet season of 1926-27. Rim-off . Many stream flo?: records have been obtained by private and public agencies in San Diego County. The United States Geological Survey has main- tained a n\jmber of stream gaging stations in the county and has published, either wholly or in part, many of the records obt-iined by other agencies. The oldest stream flow records in San Diego County arj derived from the computed inflows into the Cuyamaca and Sweetwater reservoirs. Both these records begin in the season of 1887-88. Monthly estimr.tes of inflow for the entire record are available for Swoetwater Reservoir. In the cr^-se of the Cuyamaca Reservoir, monthly estimates of inflow begin in the season of 1892-93. The next oldest stream flow record in tha county is on the Srn Diego Kivcr at the Diverting Dam. Estimates of the waste over this dam and of the amounts diverted into the Cuyamaca Flume begin in Janucjry 1899. As has been previously shown, there is apparently only a very poor relation between total rainf'-ll and run-off in this region and so although many of the stream flow records may be of doubtful ■50- accuracy, it is believed tlr.t they give r. better estimate of the run-off nhich actually occurred than could be obtained from estimates derived from precipi- tation. Beginnin/T in 1911 nnd continuinc, -t lo-ast in part, until 1924, the Volcan Land and Water Company maintained a number of stream gaging stations on the San Dieguito and San Luis Rey rivars and on niany of their tributaries. Most of the gaging stations rerc established at or near potential dam sites. The San Diego County Water Co., successor to the Volcan Water Company has continued the records at the Hcnshav? Dam and the Escondido Mutual Water Company secures records at its diversion works on the San Luis Rey Ri-:r:r and at Wohlford Reservoir. The Cuyamaca Water Company maintained and its successor, the La Mesa, Lemon Grove and Spring Valley Irrigation District is maintaining a number of records on the San Diego River and on the flume which diverts water from that stream. The City of San Diego has maintained records at the reser- voirs of its water supply system from which it has been possible to make estimates of the inflov: into these reservoirs. Mr. F. E. Green, at present hydrographer for the City of San Diego, iias been instrumental in securing many strefsa f low records and by assemblying data secured through cooperation with various agencies and the use of many independent occasional discharge measure- men-ts has made monthly estimates of thD run-off at a number of points in San Diego County. The S~'eetwater Water Corporation has maintained a record at the Sweetwater Reservoir from which it has computed the inflow into that reservoir. Altogether stream flo:? records have been maintained at 76 different points on streams tributary to San Diogo County and records were being main- tained at 37 points in 1933. The United States Geological Survey has published the stream flow record wholly or in part at 63 points on the tributary streams and in 1932 published records at 12 points. The stations on the streams tributary to San Diego County at which run-off records were available in -51- making this invostigation r-.ro 3ho:7n in Table 6, and their location is shonn on Plate I. The stations at v;hich frequent racords iverc being taken in 1933 are shown as active stations. The greater part of the run-off from tho watersheds of Srin Diego County comes in floods of torrontinl character vjhich occur .''t rather infrequent intarvals. Tho existing records indicr.tc that those floods, producing more than norm'^.l run-off may usually bo expected to occur ".t intervals of from five to six years although twice in the 46- years of record the five year flood has failed to exceed tho normal run-off. In the 46- year period of record 1387-1933 on the Sweetwater River at the SweetWvater Droi five to six-year floods occxirred in the following seasons, 1B89-90, 1894-95, 1905-06, 1915-16, 1921-22, 1926-27, and 1931-32. The floods v.'hich might have been expected about 1901-02 and 1910-11 did not occur. The total inflow in the seven flood years listed above amounted to about 64 per cent of the total runoff of the 46-year period. This extreme variation in the amount of run-off during flood and dry periods shows the necessity of large storage reservoirs if conservation and utilization of an appreciable part of the local run-off is to be obtained. Full Natural Run-off . The full natural or unimpaired run-off of a stream above any station is the run-off as it ttouM have occurred if unaltered by diversions, storage development or importation of rater from other watersheds. It is the run-off which would have occurred under natural conditions. In this investigation, consideration has been given only to tho run- off from the western slope of the peninsula Range, which includes, as has been previously shown, the greitor part of the area of San Diego County. Almost the entire present development both urban and rural, is on the western slope and future development will probably be mainly confined to this region. The -52- 3°) ;i£j ?i gS S"*s P^R'^s 2ie »>'>-| ■"3 s s -la s • « « a «)8 £ fs- e ■HMM MM MMHH 1 '^ 1« = ■Np^ f^«(^\ CiOOO oo ^ ^ >M M fW K\^\ ^ ■ « « (r>*....(.. a«>aa«ianaBaaiaM3iafnM3aaM« M fikiatcnaincea o JS ■■ *4 u n H H o o • o o o maBBh siiiiiiiiiii siiiisisiiiiiii^iiiiaiiiiiiiiiii 993» o3o3*o««» ?.t 33 ^ ^ c^ ^ ^* n n B *) B ^ 9"' 9^ O*^ 9*- J6S. . J- • casSo SS s R as S: ,» I' e s K S -,* H H B H n MM M MM H » » fw M cw N rw «4 «4 «4 ni (V irt «> iTtrt lr^ ^mtn ^ vh tf^ v««avo%a \a ^MM ru r4 «4 ^ ^ n> W stimated for these strecjns. The re- lation of the average seasonal r\ui-off at various points on the principal streams of San Diego County to the average elevation of the watershed above that point was obtained and a general relation between run-off and elevation was thus determined. From this relation, the average seasonal run-offs for the various minor stream groups Tvere estimated. The average seasonal run-offs of the principal streams at tho lowest gaging station in oach basin and of the minor stream groups at sea level for the 46-year period, 1387-1933, are listed in Table S. An inspection of the estimated seasonal run-offs listed in Table 7 shows an extremely wide variation in the discharges of different seasons. -56- ■UWt 1 susoiui rnu. utuiial mm-on' 0/ rai^cviL miuu or ttM dibo oodvtt Straam Oraliu«« area lo tqo&ra nllai tim-off In ler* rMi 1887-88 188S.89 1889-90 1890-91 1891-92 1892-93 1W3-91 1891-95 1895-96 l'9&-97 lS97-9i ' :3JWTA HJtBOAHITA MTIB ■t TBllora 7U3 13.100 32.100 18.500 11,800 19.100 22,100 7.000 98,200 3. TOO 16, coo 2,100 : :SiS LUIS HOT RITBl at Henahaw Da.it betiv«ea HanthA* Dam and ae&r Bonaall : aear Bonaall b«Cir«eQ aaar Bonsril and Oceantlda at Oceaaslda 206 312 5X8 »*7 565 15.900 13.700 29,600 1,900 31.500 35.?00 30,700 66,500 1.200 70,700 52.700 15.300 98,000 6,200 101,200 18 ,800 12,000 90,800 5.700 96,500 22.200 19.100 11.300 2.500 13 .800 25.000 21.500 16.500 19!mO 9.200 7,900 17,100 1,000 18,100 101,700 89.900 191.600 12,300 206,900 5,700 1,900 10,600 700 11,300 18,600 16,000 31.600 2,200 36,800 1,100 I 7)600 I 500 . 8. ICO 1 :SA» DIEOUITO RI71R (SANTA TSABEL CEtat) at 9uCh9rland Dam Site b«cw«OD Stttberland Iha 31t« and Hodgai Dan I at 3od£«a Daa 2^^ 303 8.100 9.500 17.900 18.900 25.900 11.800 27.800 12,100 70,200 25,800 38,300 61,100 11.700 11,100 26,100 13.200 16,700 29,900 1,800 1.300 9.100 55.300 105,500 160,800 3,000 2,000 5.000 9.800 11.700 21.500 2,200 1 1,200 1 3,100 : :SA.V DIBUO RI7SR Bo'Uder Creelc at CuTsmaca Oeuo t>«tireeo CuTamaca Dam and Dlrertin^ Dam : at DlTertlag Dam : between DlT«rtln£ Ehrc and El O^jltan Dao : at SI Capitan Daa San Tleeote Creek at San Tlcenta Dam Site : below El Capltan Dam and San Tlcente Dam Site : at Mission Sor^e 12 91 103 87 190 75 112 377 2.930 9.700 12.630 2.200 11.830 l.SOO 1,700 18.330 1,380 22,300 26,6so 8,100 }1,780 7.200 7.600 19 .580 6,130 31,600 38,030 12,900 50,930 12,200 13,700 76,830 8,520 28,900 37,120 11,500 1«,920 10,700 11,800 71,120 5,200 11,100 19,300 1,100 23,100 VIS, 30,300 3.360 15.500 18.860 1.800 23.660 1.000 1,100 31.760 2.230 5.500 7.730 700 8.130 500 300 9.230 10,730 60,500 71,230 30.500 101.730 30.300 35.500 167.530 1,210 3.100 ^foS 1.910 1.910 3.170 10.800 11.270 2.500 16.770 2.200 2.000 20,970 Ho 1 1.500 : 2.180 1 2.JS: 1 1 2.180 : :Sf3EMATra Hnrs : at Sweetwater Oaa 181 7.050 25.250 36,820 21,560 6,200 16.260 1.310 73.110 1.320 6.890 10 1 OTAT BI7IB at Lower Otay Dam 99 1,200 13.100 18,000 11.700 3,700 9,200 800 30.200 800 1,200 : :COT?0.'nroOD CHSS : at Uorena Dnn : between Horena Dam and Barrett Dko : at Barrett Dasi 111 ^9 6.000 7.700- 13.700 13.800 17.800 31.600 19,600 25.200 H.SOO 17.900 23.000 10.900 5,700 11,200 19,500 9.600 12.100 22,000 J. 300 5.200 7.500 36,600 17,100 83,700 1.900 2. 500 i.uoo 6,700 8,600 15.300 900 : 1.200 I 2,100 I isiASOHAL TOTALS 106,080 267.730 399.350 350.980 119,100 ISO .620 53.070 820,710 p. 130 121,660 18,190 t Baj>-off in Acre feet 1898-99 1899-00 1900-01 1901-02 1902-03 190>01 1901-05 1905-06 1906-07 1907-08 1908-09 1909-10 ; :3um IUBGjUIIIA siteb »t TBldora 1,100 800 9.100 5.000 8,300 2,800 25.300 61.100 19,100 15,100 29,700 28 .coo : ■.its ins EST EITiB : at Hensh&w Dan ; between Eenebaw Dnn aod near BoQuall : near Bonaall ; between near Boneall and OcaanBlde at Oceanelde 3.000 2,600 5.600 loo 6,000 2,800 2,100 5.200 300 : 5.500 11,500 9.900 a. 100 1.200 22,600 7.100 6.100 13.200 900 11,100 10,500 9.100 19.600 1,200 20,800 1.770 1.200 5,970 8.970 28,160 21,300 52,160 2,800 55,260 68.250 59.100 127.350 7.200 131.550 52,830 15,600 98,130 5,500 103,930 17.580 15,200 32,780 1,600 31.380 32.690 28.200 60,890 3.300 61,190 31.000 ': 26.700 : 57.700 ! 3.100 : 60.800 : :3i;.' DIECTIIO HITEB (SAST4 TSiBIl OBEH) : at Sutherland Dae Site : between Sutherland Dam site and Hodges DaD at Bodgee Dbq 1,600 800 2,100 1,500 600 2.100 6,000 6,000 12,000 3.800 2.700 6.500 5.600 5,200 10,800 2, 600 I, loo 1,000 11,900 19.JOO 31,200 33.650 18,990 82.610 19,060 26,670 15,730 5.990 6,700 12.690 25.110 18 .0(0 i 25.190 1 13.270 : : SAK Bisoo srras : Boulder Creek at Cyyaoaca Dam : between Cyyamaca Dam and Diverting Dam : at Diverting Dam : between Diverting Dam and El Capltan DBD : at El Capltan Dam : 3an Vicente Creek at San Vicente Dam Site : below El Capltan Dan and San Vicente Dam Site : at Ulacion Gorge 500 1,050 1.550 300 1.850 1,850 llO 610 780 200 980 980 2.670 1.580 7.250 1,000 8,250 200 200 8,650 2, 060 1,3l0 6, loo 800 7,200 200 100 7,500 2.090 8,680 10,770 1,800 12,570 1,100 1,100 15.370 120 750 1,170 100 1,270 1,270 5.530 22,210 28,070 7,700 35.770 7.100 7.500 50.370 10,620 31,550 15,170 36,800 81,970 11,000 15,500 lll,ii70 7,220 28,900 36,120 13,600 19.720 lo,6x 11,500 71,820 2.120 12,180 11.600 1,200 18,800 2,800 2,700 21,300 6,100 20,000 26,100 19,200 15.600 6.100 6,100 58,100 1.830 i 11 .HO : 19.270 ! 7.100 1 1:iS; 3.700 : 33.670 I :SIETTHTn BIVSE at Sweetwater Dan 210 820 13.760 35.000 30,000 1,ll0 16,010 9.620." :01il aiVKB at Lower Ota^- Dam 100 500 11.220 16,160 6,760 1,150 5,010 7.150 i : -OTCOllWXD CHZEK ?C Uorena Dam between Uorena Oem and Barrett Dam at Barrett Dao 700 000 1,600 200 300 500 3.700 1,800 8,500 2,6C0 3,100 6,000 2,700 3.500 6.200 600 700 1,300 11.900 15.300 27.200 21,900 32,010 56,910 18,220 23.160 11,680 1,520 5,820 10,310 13.1*0 17.350 30.830 6,320 1 8,130 : 11,150 I :SE^SC!UL I0I413 13.290 ': 9.880 62,170 39.100 61 ,170 18,310 217.310 500,860 319,020 ioe,ioo 2€1,8«0 196.960 i '.AUL: 7, (CODtlnuadl sitsoxu, TOLL liiTmix mm-orr or fsiiicipii srum or aor oiioo oooitt StrMo Drainage area In ■quare Boa-off la A«r« f««t I t : 1910-u 1911-12 1912-13 191>llt 1911-15; 1915-16 1916-17; 1917-18 191»-19 1919-20 1920-21 1921-22 ' :SA.VTi UUtOARITi BITSS •t Tst4or* 7U3 19.K00 10,500 U.OOO 20,100 56,100. 173,700 2«.600s 21,700 5.300 20.900 6.170 •5.100: :SAS LUIS RSY RI71R At U«n«]u> Dkid ao6 22 .5M) 12,760 5,910 22,630 60,110 152 ,070 29 .1(0: 21.130 7,320 23.110 5.120 101.9101 b«tw9«a a«aahaw Jam and dbat Bonudl 312 19.lt00 9,260 5.500 11 Mo 16,900 87. 560 153.500 27.710: 18.280 9.680 20.300: 3.5IO 70.920; : 3*ar Soatall 518 >tl,9lK> 22.020 1»1.530 118,000 355.570 57.220: 12.710 17.000 13.710 8.660 172.900: between near Bonaall and Ocaanilda u? 2,100 1.550 2.200 6,100 19.700 3.560: 1,710 150 2.300 19 .6901 at Ocaanalde 565 Ul.oMO 23.600 11 .110 >»3.730 151.I0O1 »5,»70 60.780: 17.150 17.150 16.010- 8.660 192.5901 zSlLl DIS^l^ITO HI7SB (SANTA TSAS2L CHSSK) At Sutnerland Db.t Site ^^ 11,900 8.690- ".520 10.U50 31,130- 17.570 95.250 13.7301 7.360 1.810 12.520 3.170 17.160: : betmeo Satnerland Dara Slta and Ho4s«a nam lU.SOO 10.830 1,260 13.930 2U.380 a9,3oo 20.330: 31 .060: 20.730: LHO 7. 310: 980 71 .»0: 121,160: at Hod«et Dam 303 26.700 19.520 5.750 78.700 31l».550 28.090 6.250 19.330- 1.150 :SAJI DI30C RITKB 3o'J.der ^rjaic at C^aaiaca Daa 12 2,160 iiiwo 2.7H0 2.3«0 3,990: 18,010 3. 730: 3.330 2.600 6.110 2.230 11.960; : beC«««n CuTatnaca Dan and Dtvertinc Qam 91 8.970 11.U30 5,260 13.200 11,890 112,720 18 .270: 8.660 5.330 21.750 3.930 71.110: I at I>lT«rtlD£ Daa 103 1U.8T0 5,000 15 .580 50,180 130,730 69.700 22.0001 11.990 7.930 31.160 6.160 83.0701 37,960: between DlTertlng Daa and Kl Capltan Oko 57 5.300 3.800 1,800 3.900 19,'<«0 16.500 6,200: 11.000 2.100 5.720 930 at EI Capltsn Ob-ti X90 16,730 I! ,670 9.500 67,380 200,130 28,200: 22.990 10.030 36.880- 7.090 121 ,0)0i San 71caste Creek at San Vicente Dan Site 75 1,600 2, loo 500 3.100 17,570 66.300 5.300. 3.100 1.600 500 2.520 36.300: 11.200: Delo« SI Capltan Dam and Sas 71c«nte Dan Sit* 11? l.HOO 2.200 300 3,000 23,300 55.300 7.100: 300 3.100 at Ulatiaa :>}r^e 377 19.730 23.270 10.600 25.580 108.250 352.030 10 .600; 30.990 10.830 12.500 7.090 201.530: SK3TtirS3 RITCT I at Sweeteater Daa ISl 3.160 5.000 920 3.520 27.0«0 160.580 15 .280: 10.200 1.050 11.910 1.810 61 .910: :OTaT RITKH : : at Lover Ota/ Dam 99 1.230 U,910 1.570 2,500 10.910 51,100 8.700: 2.710 2.3IO 9.100 110 27.110: iCOTTONlDOD CESS : I at Uorena Qkb nn 3,090 U,llto 1.750 3. 680 [>,>»50 15,010 75.270 15,730: 8.970 1.100 12 .070 3.110 12.110. between to ran* Dam and Barrett Dbd 2U9 3. 530 5,Wk> 1.380 21,050 96.900 20,200: 7.620 5.020 19.650 2.930 51.3«0: t at Barrett Dam t 6.920 9,580 3,130 8,130 36,060 172.170 35,930: 16,590 9.120 31.720 6.070 96 .500: ISKASOMAL TOTALS 121 ,580 96,330 37.'»lO 127 .9^ 171 ,830 1582.700 221,950i 157,730 55.310 155.030 31.660 786.56oi Stran 1922-23 1923-21 1921-25 1925-26 1926-27 1927-28 1928-29 1929-30 1930-31 1951-32 1932-33 II I A I I :SiUITA UABCIBIU 3ITZB 1 at Tsldora 11.610 7,350 2.210 16,950 93.150 5,680 1,020 9.550 6,200 13.630 8.720 26,2>IO 1 13A.V Ltns E2I nrsR ; &t Henahav Dsm 13.730 18.210 6,520 1.570 19.130 85.850 8,2l0 12,230 17.500 lillo 18.590 11.990 29,270 : : betwesQ HaQthsw Dam and naar Bonsall 9.650 3.S00 16,700 71.300 3.900 3.320 12.610 53.290 10.60c 25,910 1 : near Boniall 31.970 16 .170 8,170 36.130 160.150 17,110 20,550 30.110 11.190 101.830 22 .59c 55 .210 1 : batween near Bonaall and Ocaanaldo 300 2.560 1.800 9.100 210 880 1.760 7.300 81C : 3.370 : : at Oceanslde 32.270 18.730 3,170 37.930 169.250 17.380 21.130 31.870 U.190 109.180 23.130 58 .580 1 :SiB DIBGDITO EIT3S ( SA;.TA T31BEL CSSiJC) : at Sutherland Dam Site 9.560 2,710 3,170 15.310 19.550 3,620 1,890 8,0lO 3.090 31.280 W.SSO 7.600 15 ,110 1 : betvean Sutherland Jka Site and Hod^e Dam 7.570 2.810 220 20.690 109,600 6,260 1,960 9.110 2.510 11.110 23 .9» 1 39,310 1 : at Hodgei Dam 17.130 5.580 3.690 36.000 159.150 9.880 9,850 17.150 5.930 72.830 U.710 •.sm msx> «L7^ ; Boulder Creek at Cuyamaca Dam 3.160 2.300 1.610 3.350 12 ,110 2.350 3,110: 3,130 1.560 7.610 3.970: 1,520 : bet««ea Cuyam-'ca Dam and Diverting Qam 11.720 3.850 5.310 11.650 59.860 1.710 5.780 7,030 2.660 39.550 17.290 11.950- 18,150 at DlTerting Dam 15 .180 6.150 6.950 18 .500 72,270 7.090 8.920 10 ,210 1.220 15.920 22 .970 : : between Diverting Dam and £1 Capltan T>im 6,210 2.580 1.760 6.010 15,500 1.530 5.070 6,310 1.350 13,610 1.760 9.510 : at Zl Capltan Das 21.120 '•'S 8.710 21.510 117.770 11.620 13.990 16,520 1,110 5.570 65.930 20.680 32,510 : San Vicente Creak at San 71cante Da-n Site 390 30 5.510 32,670 230 510- 500 16 .710 1.320 6 ,910 : : beloa SI C^^ltan Dam and San 7lcente Dam Site 500 6,100 31,600 700 1,200 3.700 19.500 I.IOO 8,110 : ; at UitaloD Gorge 22.310 8.770 8.790 36,120 185,0lO 11,900 15.200- 19,160 9.770 102.110 26,900 17,560 1 : StSTTlATSH RIT5H et Sweetwater Dam 9.110 2.320 1.110 11,120 120,110 2.890 2.970 1I.610- 810 26.970 6.930 17.510 ! lOtlT SITia : at Lower Otay 0am 3.910 1.750 720 2,700 12,720 190 160 3.550 2.550 20.570 2,780 7.650 .COr.O.flKlOD CRSiJ : at Morena Jam 10,700 1.130 5.560 2.070 3,570 65.550 70,110 6.730 2.660 3.130 1.990 1.890- 15.9J0 3,680- 11,350 . 9.300 3.830 7.060 3.820 8.800 1.580 5.170 20.290 5,620 11.360 : at 3arrett Dair. 20,000 9.690 5.900 10.630 135.960 10.550 11.160 8.120 31.220 9.300 25 .710 :SEiSOXlL TOTALS 116,100 55,190 30.950 151.750 905,710 58.170 65.390 91.310 39.750 109.310 96.770 222,620 : : TABLE 8 AVERAGE SEASO:iAL FULL NATURAL RUU-OFF OF STESAI.IS TRIB'JTAltY TO 3M DIEC-O COUNTY Average seasonal : Drainage: run-off fc )r 4b-year: : Strea'Ti or stream gyoup LoT7er limit of drainage basin area, in: square ■ period, 13=^7-1933 : In In per : miles acre- feet cent of : total : : PRINCIPAL STRSAl.iS ; Santa Margarita River Ysidora 7^3 26 ,2U0 8.7 '■ : San Luis Rey River Oceanside 565 58,530 19.4 : : San Dieguito River Gage near Del Mar 327 ko,3ho 13.6 : Saui Diego River Old Town ^35 51 ,i+6o 17.0 : : Sweetwater River Sweetwater Dam 181 17,5^0 5.8 : : Otay River Lower Otay Darn 99 7. So : 2.5 : : Tia Juaiia River* Bridge near Nestor 461 UU ,54o ik.S : : MINOR BASINS : San Mateo to Aliso Creek : Pacific Ocean 2U1 18 ,300 6.1 ': : Loma Alto to Escondido : Creek Pacific Ocean 215 ih ,Uoo 4.7 ": : San Dieguito River below : Del Mar to Tecolate : Valley : Pacific Ocean ': US 11,800 3.9 : : Switzer Canyon to Otay : River below Lower Otay Pacific Ocean : 165 10,600 3.5 : : Totals • 3,610 : 302 ,050 100.0 : ♦From drainage area in Unite:! States. -59- This variition is graphically illustrated on Plate IV, "Seasonal Run-off of Four Major San Dioso County Streams, " on .Thich tho seasonal run-off s of tho San Luis Rey River near Bonsall, the San Dioguito Rivor at Hodges Dam, the San Diego River at Mission C-orco and tho S.veetwatur River at Sv7eetwater Dam, as listed in Table 7, have been plotted in chronological order. The varia- tion in seasonal run-offs is most marked on the S-7e3twater River in nhich there V7as no flow during the dry seasons of 1399-1900, 1901-1902, 1902-1903 and 1903-1904 and in :7hich during the vtet season of 1915-1916 there Tvas a total flov7 of 160,580 acre-feet or about 916 per cent of 17,540 acrc-foet, the average seasonal run-off for the 46-year period 1387-1933. Tho run-off of the Santa Margarita River is estimated to have been 300 acre-feet during the season of 1899-1900, and in the season 1915-1916 to have been 173,700 acre- feet, about 662 per cent of the seasonal average of 26,240 acre-feet. Although the San Dieguito and the San Diego Rivers did not become entirely dry, the minimum flows of 2100 acre-foet in 1899-1900 on the San Dieguito River and 980 acre-feot on the San Diego River are almost negligible vjhen compared with the flows during the season 1915-16 of 314,550 acre-feet, 800 per cent of the seasonal normal of 39,340 acre-feet on the San Dieguito River and 352,030 acre- feet or 740 per cent of the average seasonal flow of 47,560 acre-feet on the San Diego River. The monthly distribution of run-off also is extremely variable. In most seasons the greater part of the total run-off occurs in only two or three winter months and in the summer the main stream channels are practically dry. These conditions are illustrated by the data presented in Table 9. In this table are shown the recorded monthly flows both in acre-feet and in percentage of the seasonal total of the San Luis Rey River at Henshaw Dam, the San Dieguito River at Hodges Dam, and the San Diego River at the Diverting Dam, for the seasons of maximum and minimum total run-offs and for the seasons in which -60- PLATE 32 SAN LUIS R£Y RIVER NEAR BONSALL Mean seasonal nxvoff K.2I0 acre-feet 200 1 ■ 1 1 1 1 ~;lll 1 .11 1. 1 1 T" n nnwm ....III1III..II ILIIJ1.JI •■■.ll » 21 SAN DIEGUITO RIVER AT HODGES DAM '«- 0) o m T3 C m O Mean seasonal run-off ' 393*0 acre -feet , 1 ;^ 1 1 - 1 ± III. _. ._- Ill.lll. ill iLiJ.^ ■■1 SAN DIEGO RIVER AT MISSION GORGE c I. "to c o (/) (0 (0 to Mean seasonal nn-off ♦7,560 acre -feet ■ 1 , ■ .ii 1 Jl. 1 1 jUilL_ ... llllll lll.ll ll.ll I..I >■! ..■• a at SWEETWATER RIVER AT SWEETWATER DAM Mean seasonal ™n-off 17,540 acre -feet ■i ■ 1 + ' jIi.._L_ _JL^ . 1 ■«_a_l-_ .1 . 1. SEASONAL RUN-OFF OF FOUR MAJOR SAN DIEGO COUNTY STREAMS TABLE 9 ICWTHLT DISraiBOTrCM 07 ROI-OJT IH TIPICiL 3KAS0KS OF RBCORD CM lURBI lUJOR sroXiMS IB 3AN ODGO COUNTT siN una Bzr riybi it Hnaiw nui t season Average season t 1915- ■16 1916- -17 1920-21 1 : Uonth In In per- 1 In In per- m In per- : : : • aore-feet cent of seasonal total aore-feet 1 eent of 1 sessonal total , aere-feet 1 cent of 1 1 aeasonal t total 1 : 1 October la* 0.1 886 3,0 138 1 2.6 i : NoTMiber 268 0.1 706 2.4 1S3 3.0 I t Deceaber 756 I 0.4 1 2,560 8.7 304 5.9 1 S January 141,000 1 77.4 4,850 16.4 96« la.9 1 : Tebpuary 21,300 1 11.7 8,000 87.1 676 13.8 1 : Haroh U.IOO I 6.1 4,020 13.6 1,340 86.1 t : April 4,090 1 2.S 6,310 18.0 891 5.7 I : Vej 2,030 : 1.1 8,110 7.8 873 17.0 I : Jun* 706 : 0.4 55S 1.9 ■ 133 8.6 : 1 JmXj 188 : 0.1 118 0.4 9S 1.8 1 : August 35S 1 0.8 136 0.6 86 1.7 1 s September 155 1 0.1 840 0.8 76 l.S 1 i 1 Totals 182,068 1 100.0 SB. 483 100.0 1 5,126 100.0 t SIH mSGUITO RTTBI AT HODGKS D41I t Average season Ulnijaaa seesOB t 1915-16 1986< ■86 1984-25 J 1 ifcmth In In per- la In per- In In per- t : 1 J •er«-f»et cent of seasonal total aere-feet cent of seasonal total aere-feet cent of : seasonal! total 1 e ; October 169 0.1 163 0.4 6 0.8 1 i Hot ember 360 0.1 179 0.5 71 1.9 J t Deceiaber 750 0.8 801 0.6 615 16.7 : : January 857,000 81.7 167 0.5 316 8.6 i I February 84,892 7.9 1 8,650 7,1 265 7.8 1 : Uaroh 16,438 5.8 408 1.1 386 10.6 1 : April 7,048 8.8 30,380 84.8 1,281 S4.r i t Uay 3,918 l.S 1,488 4.1 400 10.8 t i June 1,844 0.6 861 1.0 336 9.1 i I July 980 0.3 74 0.8 11 0.8 1 X August 646 0.8 95 0.3 0. i ; September 518 0.2 3 0. 0. 1 : Totals 1 314,551 i 100.0 36.003 100.0 3,687 100.0 I SAN DISOO HITJH AT DnnfflTING DAU J }ii^-r^mnm season ATerege aeasoa ItinlBim season ; 1915-16 1916-17 1899. .1900 : i Uonth In ! In per- In In per- IB In per- t t : t aere-feet : cent of : seasonal : total aere-feet cent of seasonal total aore-feet eent of t ssasonal t total t : October 881 : 0.2 630 2.9 0. 1 : Not ember 840 : 0.8 461 2.1 4 0.9 t : December 847 : 0.6 988 4.5 1 0.1 1 i January 97,075 1 74.3 3,764 17.1 804 86.4 t : February 13,981 « 10.7 4,684 21.3 41 5.3 1 : March 10,116 t 7.7 3,647 16.6 99 7.6 : : April 4,719 : 3.6 3,631 16.0 80« 86.6 t : May 1,730 S 1.3 8,646 18.0 859 3S.5 1 I June 768 : 0.6 1,001 4.6 0. : : July 553 : 0.4 317 1.4 0. : 1 August 205 : 0.8 200 0.9 0. 1 t Septanber 223 t 0.2 137 0.6 0. 1 1 1 Totals 130.738 : 100.0 82,000 100.0 774 100.0 « the total ru.n-off raost closely approached the avarare seasonal run-off for the 46-year period 18S7-1935 on the three streaas. An inspection of this table shows that in the season of 1915-1916 the maxiinum for all three streams approximately three-fourths of the total seasonal flow occurred in one month, that in one season of average run-off, 1915-1917, approximately 70 p'jr cent of the seasonal total occurred in four consecutive months and in another 1925-26, 84 per cent occurred in one month. In the seasons of minimum flov? 1399-1900, 1920-1921, and 1924-1925 the maximum monthly flow ranged from 26 to 35 per cent and at least 60 per cent of the seasonal total occurred in three months. The daily distribution of flow is even more variable. In the summer time the daily flow falls to practically zero on all the major streams tut in flood periods more than the average seasonal flow may pass in one day. This is shown in Table 10, in which are listed the maximim mean daily flows recorded at the more important gaging stations of San Diego County. When compared rath the mean seasonal flows for these stations listed in Table 7, it will be seen that in every case the maximum mean daily flow of record is larger than the average seasonal run-off. Xihen compared with the seasonal run-off for the season in which the flood occurred, it will be seen that the maximum mean daily flows in all cases are over 20 per cent of the total seasonal flow. -62- Table lo. MWZB'IUM ivEaN D..ILY FLOV.o IN PRIHCIPAL SI-RSaAIS TRIBL'I^J^Y TO SAW DI2G0 COUl^ITY : Stream Gag Lng Station Mr.ximuia Flow Second- feet ■ Date : tS^nta Margarita River Near Fallbrook (1) 21,900 Feb. 16, 1927 \ : San Luis Rey River At Henshaw Dam 28,100 Jan. 27, 1916 j :San Luis Rey River At Oceanside 95,600 Jan. 27, 1916 ] ;Santa Ysabel Creek At Sutherland 10,800 Jan. 27, 1916 ] :San Dieguito River At Hodges Dan 37,200 Jan. 27, 1916 | :San Diego River . At Diverting Darri : 12,000 :Feb.l6,1927 : .San Diego River : At San Diego *. 38,000 i Jan. 27, 1916 i : Sweetwater River ; At Sweetwater Dan a 18,100 Feb. 16, 1927 : : Cottonwood Creek At Morena Duin 8,600 (1) iZ) Jan. 27, 1916 : : Cottonwood Creek At Barrett Dam 18,900 Feb. 16, 1927 : (i) No record in 1916 (r.) Includes computed natural flovf from area above Morena Dam -63- CHAPTER III WATER SUPPLY DEVELOPLEl^T AITO UTILIZATION lU SAI'I DIEGO COUNTY The climate of San Diego County is extremely mild and equable along the coast, changing to greater variation with the higher elevation of the mountains to the eastward, and to a desert climate east of the crest of the divide. The climate is one of the major factors in the development of the county, being favorable not only for living conditions but also for the production of a wide range of cropsy including a variety of semi-tropical fruits, and of winter-grown vegetables. The rainfall occurs during the wet or winter season with practically no rains falling between May 31st and October Ist. The amount of rainfall increases gradiially from the coastal plain to the mountains. In general, it is insufficient to mature crops without irrigation* The first development of a v/ater supply in San Diego County began early in the nineteenth century when the Mission Fathers constructed a masonry dajnand a tile lined masonry conduit to divert and transport the waters of the San Diego River about six miles from the upper end of Mission Gorge to the valley lands in the vicinity of the San Diego Mission. The q-aality of this construction is evidenced by the fact tliat practically the entire dam and many portions of the conduit are still standing. Modern developments may be said to have begun with the com.pletion of the California Southern Railway (now the Atchison, Topeka and Santa Fe Railway) in 1885 and the resulting real estate boom. But few ditches were constructed pre- vious to this time and the area irrigated was in small and scattered tracts. -64- A grant of 10,000 acres of the best Linda of Rancho de la Nacion and other lands had been nade to the railroad. This led to the construction of Sweetwater Reservoir in 1887, providin^i' a municipal supply for national City and an irrigation supply for the adjoining agricultural lands. About the same time the San Diego Flurne Company constructed Cuyjxmaca Reservoir, the Div,ertinf Dam on the San Diego Hiver uid the v;ooden flune about 36 miles in length from the Diverting Dam to the vicinity of La Mesa. This systeri brought domestic water to the city of S^^n Diego and m irrigation supply to the El Ca,jon Vi-lley .-uid adj.iccnt j.gricultural arcis* The Escondido Irrigation District, formed under the Uright Act in 1887 and predecessor of the Escondido i.Iutu-.l li'ater Cor-ipany built the Escon- dido diversion works on the 3an Luis Rey River, the conduit and Bear Valley (Wohlford) Reservoir, briiiging an irrigation supply to the Escondido Valley in 1695. The Southern California Mountain V.'ater Company, incorporated in 1895, took over the properties of the Mount Tecarte Land and \iuter Company on Cottonwood Creek, and the Otay V/ater Corap.-^ny on the Otay River starting the construction of the Upper and Lower Otay and Morena Daras, about 1896, The first two projects wore completed but the construction of Morena Dam was stopped after building' to only 30 feet above the streuj-i 'bed. In 1909 the Dulzura conduit for diversion of water frora Cottonwood Creek to the Otay basin v/as completed, and work on the Morena 'dim was again started and carried throujjh to completion in 1912. This system was purchased by the City of Son Diego in 1913. Since then the Lov/er Otay D.'tm v/hich failed in the flood of 1916 has be.n replaced, Barrett Reservoir '/as built in 1922 and the capacity of the Morena Rescirvoir has been increased three times. Further major developments occurred in 1918, V7hen the Santa Fe Land Improvement Company built the Hodges Dun and Reservoir on the San Dieguito River for the purpose of supplying' irrigation and domestic service -65- to the coastal belt north of S,in Diego, The City of San Diego acquired this development under a lease option to purchase contract in 1925. In 1922 the San Diego County Water Company built the Henshaw Reservoir on the S;-m Luis Rey River, which provides an irrigation supply for the Vista Irrigation District and a supplementary supply for the Escondido Mutual Water Cauvany. The City of San Diego has recently completed the El Capitan Dam and Reservoir and the 1934-35 run-off of the San Diego River is being stored. These major developments have been augmented throughout the entire county by many wells and pumping plants. Since 1910 a n'jmber of irrigation districts and mutual water companies have been organized. These have, for the most part, either taken over the privately owned systems pre- viously supplying the area or have puj^chasod their water wholesale frcxn other agencies. At the present time the only major privately owned systems retail- ing water in the county arc the Sweetwater Y/ator Corporation and the Coronado Water Company, both of vvhich are under the same management. Agencies Furnishing Water S e rvice . Accurate segregation of the water supply between irrigation and domestic uses in San Diego County is difficult. Many of the farms are small and much of the irrigated area is semi-residontial in character. Many of the water service agencies make no distinction between irrigation and domes- tic use in their sales, and of those that do, only a few have t-^bulr.tcd the data. Practically all of the irrigation agericics serve appracio,blc urban areas and three, Lakeside, Ramona and San Ysidro irrigation districts arc primarily for domestic supplies. The Coronado Water Company, and the City of San Diego, however, have very few irrigation services. The areas served by the organized agencies except Indian Reservations are shov/n on -66- Plate V, "\tatiir Service Areas of Org.mized xicjucies in 3;i)i Diego County," A short history and description of each agency is given in the follov/ing pa.ges. Irrigation Districts - The Fcillbrook Irrigation District, comprising a gross area of 3,915 acres of the Fallbrook Plain in the vicinity of the town of Fallbr^ok, was formed in 1925 and represents a second effort to develop an irrigation district in this area. The first district was formed under the original Wright Act in 1391, with an area of 12,000 acres. After considerable litigation, the original district was dissolved. The present district up to date has neither secured a water supply nor worked out a final plan for the project. About 1,500 acres within the district boundaries were irrigated in 193i through private pumping plants. Ho capital investment has been made in irrigation works. The La Mesa, Lemon Grove and Spring Valley Irrigation District was formed in 1913, and embraced the lands around the towiBfrom which it takes it name. The district, however, after voting bonds, failed to negoti- ate successfully the purchase of the system of the Cuyanaca V/ater Company, or to construct other irrigation works, and rem:i,ined inactive from 1915 to 1924. All of the original bond issue except $56,000 used for purchase of lands were withdrawn from sale and burned in 1923. In 1925, the district igain voted bonds and purchased the Cuyamaca systeii for ^1, 226, 529,92. The gross area of the district in 1933 was 19,019 acres, of which about 2,600 acres were irrigated. The district also furnishes irrigation \/ater to some small areasoutside the district, rauiiicipal and domestic supplies to the cities of La I.Iesa and El Cajon and the adjacent unincorpor-ited ;ireas, and from Murray Reservoir at the lower end of the flune and ditch has served an auxiliary supply to the municipal system of the City of San Diego. -67- PLATE "Y 3 'I y I u A a 1/^ / 1 Follov/ing a State Supreme Court decision confirming the City of San Diego's paramount right to the v. aters of the San Diego River, an agreement was made between the district and tlie City of San Diego whereby the district is allowed to divert up to a ma::imum of 27 second-feet at the Diverting Dam, in addition to the v/ater conserved by Cuyamaca Reser- voir. An exchange of storage facilities allov;s the district tht- use of 10,000 acre-feet of storage capacity in El Capitan Reservoir v/ith addi- tional temporary storage during summer months, while the City of Sun Diego is given the use of 5,000 acre-feet storage in Murray Reservoir, and title to several parcels of land. The present works, described in sone detail in Chapter VI, con- sist of Cuyaraac=A Reservoir of 11,595 acro-feot capacity, the Diverting Dam, the La Mosa flume and ditch. South Fork feeder flume, Grossmont, Eucalyptus, Mt. Helix and Murray reservoirs, the El Monte wells and pumps including booster pumpw and the distribution system. The capital invest- ment on December 31, 1933, was ,$2,385,031. The income from water tolls on 3488 .?.cre-feet in 1933 ;jnounted to ,^147, 817 or $42.38 per acre-foot. On January 6, 1934, the district was granted a loan of $600,000 from the Public 'works Administr ition for the- replacement of the existing wooden flumes with a concrete pipe line fran El Honte tunnel to Eucalj^jtus Reservoir. Of this ;jnouiit, $132,000 is a direct griint. A loan to the dis- trict of $1,347,768.40 was authorized on November 24, 1933, by the Recon- struction Finance Corporj,tion to provide for the refunding of all bonded indebtedness, ;ind unpaid interest coupons falling due prior to January 1, 1934, at sixty ceuts on the dollar. The July 1, 1932 interest, a portion of which has been paid in £ull by the district, \/a3 jxiid in full, the district contributing 40Jj of the amount v/itJi the remaining 6O5& provided in tiic loan. -68- The refinancing of the old bond issues and the reconstruction of the flume will materiailj- reduce interest and operating- charges. The Lakeside Irrigation District, organized in 1924, comprises a gross area of 320 acres consisting of residential lots and small tracts in and adjoining the town of Lakeside. Although organized as an irrigation dis- trict, its operation is primarily for domestic use. In 1933, 23 acre-feet were used inside tne district, all for domestic purposes, 33 acre-feet were delivered for the irrigation of 22 acres of orchard outside of the district. The capital investment less depreciation amounted to i?28,117,57 on December 31, 1933, and includes the right to 4 miners inches continuous flow from the La Mesa Flume, 6 acres of river bed land, a well vjitii deep-v/cll turbine pump, a booster pump ajnd. storage tank, and a steel pipe distribution system. An issess- ment of $5,663 was ievied in 1333. The total income of the district frori as- sessment .md vrater tolls v/hs $5,320 and from otlier sources ;^,454. The Piomona Irrig-tion District, organized in 1925, comprises a gross i,rea of 660 acres, including the town of Hsanon-.. The district serves R-jnona with domestic water and 20 acres wore reported irrigated in 1933. The physical works include 12 woIIj along Santa Jjiria Creek with pumps, storage tanks and ajpipe distribution system. The capital investment in works to December 31, 1927, including legal services raid interest, amounted to ^95,946.81. Ko additions of any consequence liave been made since that date, water tolls collacted in 1933 amounted to i^5,308 for a total delivery of 200 acre-feet, an average rute of ^25.54 per iicre-foot. $5,037 of assess- ments also were paid in 1933. The S^n Dieguito Irrigation District, organized in 1922, is located on the coastal plain about 25 miles north of San Diego. Tlie district covers a gross area of 4,000 acres, which includes the towns of Encinitas and Cardiff. Aoout 1,570 acres were irrigated in 1933, The source of water -69- supply is HodgGS Reservoir and the San Dicgulto Hiver. The vritcr is purchased from the City of 3 in Diego, which hr.s a leaso-option to purchise contract on the Hodces system. The v.ater is conveyed from Hodges Reservoir through C-^rroll conduit for -.'bout 4 miles to San Dieguito Reservoir, a small regula- ting reservoir, where delivery is made through the pipe line and distribution system of the district. Three booster pumps lift water to lands above gravity distribution. The total investment less depreciation on December 31, 1923 was |311,596. In 1933, ^29,129 was collected for water and a total of 1,950 acre-feet of water delivered for irrigation and domestic use at an average charge of ^14.94 per acre-foot. ;^4,057 of assessments were paid in 1933. The Santa Fe Irrigation District, organised in 1923, is located on the coastal plain directly north of the oan Dieguito River ibout 20 miles from San Diego and has a gross iri.'a of 10,106 acres. In 1933, 2,630 acres were irrigated. The Santa Fe District, like the San Dieguito District, obtains its water supply from Hodges Reservoir through the Carroll conduit and S-in Dieguito Reservoir. The physical works comprise a distribution system of pipe lines, with a number of sm.ill distributing reservoirs and booster pumping plants to reach the -irea above gravity distribution. The total investment in v« rks to December 31, 1933 was $722,054.62. In 1933 a total of 2,980 acre-feet of water was delivered and water tolls Avore collected to the amount of $80,212, or at the averiige rate of |26.92 per ;icre-foot. An assess- ment was levied of ;Jl31,a50, The San Ysidro Irrigation District was organized in 1911. It is loc_ted on the right bank of the Ti.i Juana River, just north of the inter- national boundary line, and has a gross area of 532 acres, including the town of San Ysidro. The district is mainly residential. Only 100 acres were irrigated in 1933. The present system of the district embraces 5 wells, located in the water bearing 1 uids in the Tia Juana River chanjiel, -70- r- . .1 .. ;■- a 625,000 gallon concrete reservoir and a pipe distribution system. The capital investment less depreciation to August 1933 was reported as $63,076. In 1932 the district delivered 368 acre-feet of water and collected water tolls to the amount of ;^9,584, or at the avora^'e rate of $26.32 per acre- foot and collected ;^,862 in assessments. The Vista Irrigation District, organized in 1923, is located around the town of Vista, about 10 niles inland from Oceanside, and had a gross area of IS, 23d acres, of which 6,766 acres were irrigated in 1933. The wattir supply for the district is obtained from the Hensliaw Reservoir on the San Luis Key Hiver by purchase from the S;.vn Diego County Water Company, Th3 water is released from the reservoir, flows down the 3."n Luis Hey River channel and througn the Escondido ditch to Wohlford Reservoir. After passing through the Escondido Mutual V.'atcr Company* s pov;er plant, the water is delivered to the district's main supply conduit. The physical works of the district include the main supply conduit from Bear Valley Power plant, the Pechstein Reservoir of 200 acre-feet capacity, 7 circular concrete equalizing reservoirs, and a steel uad concrete pipe distribution system. The capital investment on Decern oer 31, 1933, was $1,686,722. In 1933, the district collected water tolls to the amount of $104,833 and delivered 5,700 acre-feet at an average charge of $18.40 per acre-foot. The district also collected $78,112 from taxes. Mutual Water Companies - The Carlsbad Mutual Water Company, organized in October, 1914, serves a gross area of about 11,000 acres extending from the "boundary of the Santa Margarita y las Flores Rancho, approximately half a mile north of the 3an Luis Hey River, south to Aqua Hedionda Creek including the unincorporated community of Carlsbad and more than half of the .area of the incorporated City of Oceanside, In 1933 a net area of 2,000 acrts, of which only 300 acres were within tlie corporate limits of the City of Oceanside, -71- were served by this compai-iy. The present v/orks consist of three wells in the San Luis Bey River Valley, four distributing reservoirs and a pipe dis- tribution system, together with the necessary pumping plants. The capital investment as of Decenber 31, 1933, was $250,000 with the water rights carried on the books at a nominal value of i^l.OO, 1,927 acre-feet of water were supplied in 1933 for a net charge of ••^29,923 or ^15.53 per acre-foot, which carried the operating expenses. The cliarges for depreciation and improvement were met by an assessment of -58,000. The Escondido liutual V.'ater Company serves water and electricity to a gross area of 13,230 acres in Sscondido Valley. The active development of the Escondido Valley began during the boom of 1885-88. In 1887 the settlers formed the Escondido Irrigation District under the V/right -ict. At this time the district did not contemplate the development of a water sup- ply but hoped to purchase water wholesale fron some private organization. A bond issue of $450,000 was voted, $300,000 to be pa id for T/ater -at the edge of the district, and .$150,000 for a distributing system. The plan, how- P ever, failed and nothing was done. In 1893 the district decided to develop its own supply from the San Luis Rey River at -in estimated cost of about .^17 5,000. The bond issue, therefore, was reduced to $250,000. This, how- ever, proved inadequate -and a further issue of $100,000 was m ;de before the system was completed in 1895. During the p-sriod of litigation over the constitutionality of the Wright Act, many of the property owners refused to pay their assessments and in 1899 trustees for the bond holders took over the system. In 1904 the bondholders -agreed to relinquish the system for $225,000 cash payr.ble in one year. The property owners, organized the Escondido Mutual Water Company and in 1905 raised the necessary money by a voluntary assessment of $43.00 per $100.00 assessed valuation, bought the bonds and dissolved the district. ■72- The system as originally constructed comprised an intake tunnel for diversions fror. the San Luis Rey River, a conduit to V.'ohlford Reservoir, known as the Escondido ditch, the reservoir xnd a ditch and pipe distribution system. The diversion tunnel was located n; ar the west line of Section 33, T. 10 S., R.l E. and was 356 feet long heading on the left bank of the river 3 feet below low water level. The transmission conduit hud a capacity of 28 second feet and consisted of 12.7 miles of open ditch, 2.7 miles of timber flume and a 450 foot tunnel discharging into a creek tributary to Wohlford reservoir. The r eservoir h.^ving a capacity of 2,619 acre-feet was formed by a rock fill dam on Bear Valley Creek in Sec, 6. T. 12 S.R. 1 V/. , 76 feet high, having a crest k ngtli of 380 feet, and top width of 10 feet. The downstream slope of the dam was 1^ to 1 for the lo'./er portion, and 1 to 1 for the upper, while the v;ater slope was g- to 1 -^nd covered with a timber facing. The facing extended three feet .:-bove the drvrn crest. The spillway channel around the right end of the dam was 25 feet v/ide .^nd 6 feet belov. the crest of the dam. The distribution system consisted of a small pickup wier about half a mile oolow the dam, 16 miles of pipe line cind 15*5 miles of open ditches and flume. The d;un was topped during the flood of 1916 but did not fall. However, settlement occurred which strained the plank facing, causing large leakage and necessitating repairs. The spillway was enlarged also. In 1924 the dam v/as raised to a lieight of 100 feet by placing a hydraulic fill blanket on tiie upstrean face and a siphon spillway with its crest five feet below the top of the dam constructed. This increased the reservoir capacity to 7,225 acre-feet. In 1932 the spillvvay capacity was enlarged by the construction of a side channel spillway 80 feet long. About 1925 the capacity of the iSscondido ditch was increased to 70 second-feet and lined with concrete. A concrete diversion dam has since been constructed at the intake on the San Luis Rey River. Two power houses have -73- been constructed, ont; a,t Rincon with an installed capacity of 300 kilovolt amperes to utilize tlie v;j.tiiT released for the Rincon Indian Reservation Jid the other at Bear Valley oelow Wohlford Reservoir \^ith ;.n installed capacity of 800 kilovolt apmeres utilizin(i the head between the reservoir water surface and the intake of the distribution system. The distribution system now comprises fi5 miles of pipe lines with no open ditches. The capital investment on February 28, 1924 amounted to ^97,000 of which ^14,000 was for water services and $183,000 for power. The gross area served, as stated, is 13,230 acres of which 7,223 acres were irrigated in 1931. In the year ending Febr'oary 28, 1934, 7,042 acre-feet of water were sold for irrigation at a rate of .^2.52 per acre- foot plus a service charge of $0.75 for each irrigation and $0.25 for each requested change in head. In addition to its irrigation service, the Es- condido Mutual Water Company wholesales water to the City of Escondido for municipal uses, 421 acre-feet having been delivered for this purpose in 1933, and acts as a transportation agency, deliverying water from I^ke Henshaw throug'h the Escondido ditch and Bear Valley power house to the Vista Irrigation District cfanal. The Lakeside Farms Mutual Water Conpany was organized in 1910 to serve a gross area of 966 acres north of the San Diego River in the vicinity of Lakeside. 451 acres were irrigated in 1933. The existing works consist of two wells and puiips drawing from the San Diego River gravels, two booster pumps and a reservoir. The capital investment on December 31, 1933, was estimated to be about $25,000. The water rates in 1933 w«re 4 cents per 1,000 gallons under 100, COO gallons per month and 3 cents per 1,000 gallons over 100^000 gallons per month, with a minimum charge of $3,00 per month per meter. Low areas not requiring the use of the booster pumps were served at a rate of 35 cents per hour for the use of the low -74- lift pump. In 1933 the receipts from Mvater tolls were 1^2, 989 and $1,538 from assessment. The Pauna Valley Mutual Water Company was organized in 1914 to serve a gross area of 496 acres in the San Luis Rey Valley about 5 miles east of Pala. 403 acres were served in 1933. The existing works consist of a diver- sion weir on Pauma Creek, 3 miles of 14" pipe with boxes and gates for distri- bution and cne well and pump. The company has a water right of about 190 miner's inches on Pauna Creek, subject to the prior right of 30 miner's inches of the Pauma Indian Reservation. The v/ell and pump were installed to supple- ment the gravity supply during late sumner and fall months. The capital investment on December 31, 1J3.5, was ^18,700, V/ater tolls are ^3.00 per acre for all the v.ater available. The users pay pumping charges estimated at 25 cents per hour for well water. In 1933 about 1^0 inches for 8 months and 10 inches for 4 months were available. The Rivervie;.- Farms Mutual \;ater Company was organized in 1316 to serve a gross area of 1,290 acres south of the oan Diego River in the vicinity of Lakeside. 144 acres were irrig.ited in 1933. The present works consist of two wells and pumps drawing from the San Diego River gravels, booster pumps, four small regulating reservoirs and distribution system. The capital investment on December 31, 1933 was estimated to be about $b0,000. In 1953, 156 acre-feet of w:.ter were sold for a total of $4,919 an -verage rate of ^2^.63 per acre-foot. Assessments and miscellaneous items increased the income of the company by 32,185, Incorporated Cities - The City of S-an Diego now owns and operates its entire water supply system serving water from the drainage basins of Cottonwood, Otay, Son Diego and San Dieguito rivers. The first successful organized effort to provide :. water supply for this city began with the incorporation of the San Diego Water Company in 1873. This company had drilled a well -75- nc-.r the southeast corner of the pirk and commenced deliveries before M.rch 1874. In 1875, however, the supply became inadequ.ite and the company be£-an pumping from tlie welis in the gra,vel3 of Mission Vr.lley. In 1889 the San Eiego Flume Company brought in the water from the San Diego River ind Cuyamaca Reservoir .nd in 1894 the San liego Water Company and the San Diego Plume Conpuny werw consolidated. In 1901 the City purchased the Mission V:.llciy v/ells md the distribution system within the city limits. The supply was obtained from the Mission Valley v/ells and the San Diego Flume Company until 1906 when the city began the purchase of water from the Southern California Mountain W iter Company, supplied fran the Lower Otay Reservoir, In 1913 the city purchased the system of the Southern California :.feuntain Water Corr.pany ".nd since that time both the storage and distribution of v«ater have been in municipal control. The system at that time consisted of a low d..m at Morena Reservoir, the Dulzura Conduit, the Upper and Lov.er Otay reservoirs and transmission pipe line to the city. The system has sinc« been enl.^rged by increasing the c-ipacity of Moren/i Reservoir, by the construction of Barrett Reservoir, by the replacing of Lover Otay Dam destroyed by the flood of 1916, by the purchase of Hodges Reservoir and other properties on the San Dieguito River, by the development of the upper San Diego River underground basin and the construction of El Capitan Reservoir. Moreni Reservoir now has a capacity of 65,800 icre-feet v;hen w;'vter is stored to the top of the spillway gates. The reservoir is formed by Morena Dam located on Cottonwood Creek in Section 14, T. 17 S. , R.4 E. The dam is a rock-fill structure 179 feet high with a crest lfc;igt]i of 550 feet. The dow.. stream face has a 1 l/3 to 1 slope wnile the upstreV;! face has a 0.9 to 1 slope with a rubble and reinforced concrete facing. The side channel spillway located at the right end of the d.un is 312 feet long and the flow may be partially controlled by gates. Water released from Morena Reservoir flows -76- down the natural stream channel of Cottonwood Creek to Barrett Reservoir. Barrett Dam which forms this reservoir is located on Cottonwood Creek in Section 22, T. 17 S. , R.3 E. It was constructed in 1922 and is a gravity concrete structure, arched in plan, 160 feet high with a crest length of 750 feet. The over-pour spillway is 307 feet long and 18 feet deep. It is partially controlled by gates, and the reservoir capacity v/hen water is stored to the top cf the gates is 42,900 acre-feet. \/ater released from Barrett Reservoir is conveyed oy the lulzura Conduit for a distance of 13.5 miles, discharges into Eulzura Creek and flows down the natural stream channel into Lower Otay Reservoir. The conduit is concrete lined and has a capacity of 60 second feet. The Savage Earn formerly called the Lower Otay Lam was officially renamed by Resolution No, 61,885-, adopted by the Council of the City of San Diego on July 9, 1934. It Torms the Lower Otay Reservoir and is located in Section 18, T. IB S. , R. 1. E. , a.id Section 13, T. IB S. , R. 1 W. on the Otay River. The present dam is a gravity concrete structure, arched in plan, 151,5 feet high, with a crest length of 700 feet and was built in 1919. Two spillways having a combined net length of 448.5 feet are partially controlled by gates. The reservoir has a storage capacity of 56,321 acre-feet when water is stored to tlie top of the gates. The water released from Lov/er Otay Reservoir passes tlirough a filtration and chlorination plant and is delivered to the various city regulating reservoirs through transmission pipe lines. The Upper Otay Dam, which forms the Upper Otay Reservoir, is located on Proctor Valley Creek in the Otay (Dominguez) Rancho in what would be Section 36, T. 17. S. , R. 1 W. , if the section lines were extended into the grant. The dam is a concrete arch 79.5 feet nigh witli a crest length of 350 feet. The reservoir capacity below the spillway lip is 2,793 acre-feet. The spillway is an overpour t;,T)e 22 feet long. V/ater is released directly -77- into Lower Otay Reservoir. Hodges Reservoir has a storsige capacity of 37,699 acre-feet and is formed by a multiple arch concrete dan located in Section 18, T.13 S. , R. 2 V/. The dam is 130 feet hi£-h above stream-bed and has a crest length of 729 feet. Ai\ overflow spillway 341 feet long with its lip 15 feet below the crest of the dam is located at the right end of the dam. \;ater is released from this reservoir and carried through the Carroll conduit to San Dieguito Reservoir where it is distributed to the Santa ?e and San Dieguito irrigation districts, to Del Mar Water, Light and power Company and to the City off San Diego, The San Dieguito Reservoir is located in the San Dieguito Rancho, in Escondido Creek drainage basin in what would be Section 16, T. 13 S. R. , 3 W. if the section lines were extended into the grant. The reservoir is formed by a multiple arch darn and has a storage capacity of 1,128 acre-feet. The Hodges system, and other properties on the San Dieguito River were ac- quired in 1925 by the city on a lease-'option to purchase contract. Under existing contracts the city is obligated to furnish a total of 10,500 acre- fet;t annually from Hodges Reservoir to the Santa Fe and San Dieguito irrigation districts and the Del I,Iar Water, Light and Power Company. In 1925 the city began construction of Sutherland dam and reservoir on the main stream of the San Dieguito River, which is known as Santa ysabel Creek above Hodges Reservoir, but abandoned the project before completion. The dan site is located in Section 21, T. 12 S., R. 2 E» The El Capitan Dam and Reservoir on the San Diego River have been recently completed and plj.ced in operation. The dam is located in Section 7, T 15 S., R, 2 E. A somewhat detailed description of it is given in Chapter VI. The reservoir will have a storage capacity of 116,900 acre-feet. Data descriptive of the d-j^s and reservoirs mentioned above .and the regulating reservoirs of the distribution system of the City of San Diego are presented -78- ■■ " ^ " .. ^ " * • * •■ • • • • • * rH rH " ■tJ >_^ N^X >> CD o o o o o o o o CO t!^ ^ o o cr O (1) c3 M .1-1 Ch CO o> CO ^cA cr\ r— J- o rH OJ -■d-^^ no 1 ^ "» •■ Td CO ^^ n5 CJ (D ir\ oj CM v£) vx) 1^- CO LPi r-i VO lO >3 d rH O Ph mH ;^ V£) J- LTiO r^ r-i rH +> s vh cd 4i fl) O rH ro r^ ■rl O 4J CO o d he C been ity e to +3 CS> Xi >i i~- c\j cr>v£) o 1 — O 1 1 m *3 Tii *^ d c CM \D r^VjD tiC' rH O I 1 C jd +3 O CS r-i * fH r-< rH rH rH S 0) o O Q) -H P. O ■P W) -d -rl 0) CC C ^1 i-H f^ P. ■H n3 P^ nS m r-H ^ fH C^" -P o w C M .r< -d * O o «H P. E S Cm > C O -H p (U O ^H o r-H -p ur\ ITS O r-f O ir\ o cr\ CO (D (D -H C 4J -S J- rH ltn a^^r^^H ,Tf ^ rj 5h 0) 01 HJ •t-l t? (U O vo ir\.d- r— r^ lr^ CM ^ fcfi M CD ci (1) • r/5 cd q K E»fl cd 'H ra 1—1 • C j:: C fn > rH fl cis cd CJ cd !-. 0) -H ■H • « 43 -H ^ & rough an e, Capi the ^ rH ^ -P rH >a EH O W ^ O t-f •H (h .r! ^ C! "d '^ 53 • P .r4 0) +S CO 5 CD -H 0) g -d > o Xi o ^ cd 1 CJ P, CO tM ^ 2 ^°« ^ ^ Ph CD O 01 -H o cd Cd U -n o o o O +3 tH ^ 0) rH +> -rl aj (D Q) Id cd o o & ■H +J CD -P P, rH rH flfl -H Pi P< OJ -H -P ^ E^ r. .H -U -rl d -H S > t« > fi -P •rt •H ^ 1 — Jh Q) 5 4J +> +3 CO in a P -3 r-i - HH fH ^> MD 1 -rl w c5 o e- w s •^ f^ rH |>, (D O rH fH > rH O fn 01 rH Cd (D "- " -M t:) ■H cd 01 o ^ 0) > O Q> flj rO +i r- cj CM O r-- ir~ r- rH t^ ^1 O « +:> & V.O ^ r- J- O^ rH o ^ ^ •rl tlfl O .fl rH > P CD rH rH r-i r-i r-{ rH O C - >s W rH O CD Vi > •H o cd •H .H r^ (U ^H f-l rH ^H 0) p. nJ S-l c e OP. ^1 . W ta +5 10 -H 03 +3 CO > an Res and S tilize in Mu e-feet o m o •d =M 43 0) CJ O cd Cd cd f-i cd Pl, Q) ti u a rH >; >- U 0) cd o rH +i +> CJ c!) 6 01 o Ai ^ o > >» > o O •H •H CO rt 0) t-i en ^ O u rH C +3 Ch CO o a) (D >j (D pc; ■H o P P B -H LO, -IJ O O rH -HO cd Cm tlH Ch Cd cd Vi 01 f-i +^ n3 r-i PI 4J ft o o o o o O 1-^ +5 (U 01 o t:) Td c^5 ^^ -H cd 01 OJ -H o O O > CD O p! o o > W) W CJ >1 c; >5 >J W (D >i - -H (h t^ !h o U M U M fT ^ ■p Cd -d 1 ^ ^ & fn -H 0) (D OJ cd >:, cd CD cd 0) •H •H 01 (DO a d O « -H .H ^ 40 § H-> 0) +5 0) 4J fH o 01 c: ;h -H o o -p O Q pi pi ^1 p( ^^ Cd o cd 3 o o ^ ^o -lo O >^, (h ^ O rO O ^ o rH -p ft -H cd & 4J -p o ct; q q o O ^^ -P erf cti o •rl •H ■H S 01 cd cd 43 -(-> ^1 ^ h O h:) cd O Ch O O PL, O CO w C/5 1 { E-H EH EH ^1 •d •H f^e O o 0) 01 -H O CO +» fn ir\ 43 cd .. .. rH ■tJ Cd ,£> U •H .H o •C« +3 e o -d 01 o e^ (D o o 43 c; 01 N cd 01 cd ^ .H pi, u O rt B-i o ■ M +J •H CO +3 rH cd O >; l>a fl •H -^-^-^ r-\ O -HO > cfl c3 cri "^ s, cd frj)^ +3 u -(-> +3 +> tiO^ 0) cd Cd 43 01 o ;:! 01 a> ■P O O -H c: ® M +> +3 O -H •H M 43 « ^1 o cd m n! HJ P( w •H >s xj cd (D tn (U ID G 0) tn f^ Cd CD -P cd Q rH U C r-i & .-^ fH « f^n (D !^ 0) (D CJ> W cfl ^1 M P, & -d Cj t^ rH O -H O 01 q 01 o •H Cd >j a^ +^ § O C cn (D t-l O Cd P< O rH O o s m ;5^ K^ w w ^ O Cd HJ EH CO /O P» (0 CO o o ^ en -tJ o •• — V CO W .. r-< ■79- in Table 11. Throughout its operation the municipal system of the City of San Diego has had a connection with the San Diego River system built by the San Diego Flume Company and now owned by the La Ilesa, Lemon Grove and Spring Valley Irrigation District and in many years additional water has been purchased from this system. The wells in iifission Valley and underground supplies developed about 1927 in the San Diego River beds at Riverview and neor Lakeside have also been maintained and are dravm upon from tinfe to time for ^additional supplies. The annual safa yield of the s'lrfQce storage system of the City of San Diego after El Capiton Reservoir has been filled has been estimated to be 21,660 acrc-fcet. No estimates of the probable safe yield from the Mission Valley, Riverview nnd Lakeside plants are available. The grfvel beds in the upper San Diego River Valley are nlso dr-iv/n on by the La Mesu, Lemon Grove and Spring Valley and the Lakeside irrigation districts, the Riverview and Lakeside muturl vater companies, and numerous private pumping plants. The annual drafts ■Rithin the city limits on this system since 1897 are sho?rn graphically on Plate VI, "Grorrth of Population and Consumption of 7ater in Corporate Limits of San Diego" and listed in Table 12 together with the population of the city as given by the United States Census for the ytars 1900, 1910, 1920, and 1930 and the per capita use in these years. The sudden drop in per capita use after 1929 is probably the result of the depression and it is believed that recovery Till bring a return to a per capita use approximating that of ef.rlior years. In addition to the municipal draft of 5,536 million eallons or 17,010 -.cre-fcet in 1933, the city system also delivered 5,050 acre-feet to tr.e San Dieeuito and Santa Ft. irrigation districts and the Del Lar 77ater, Light and Po-.7er Company under the contracts taken ovar -hen the Hodges system -80- TA3LE 12 GRO^TTH OF POPULATION AJJD CONSUI'IPTION OF WATER IN COHPOHATE LIMITS OF CITY OF SAII DIEGO : Year : Population : Water consumption Annual tot-^.l, Average per dpy , : Average per in millions : in millions : capita per day , : of gallons of gallons : in ^'^llons : ': 1897 ': Ikk '. 2.039 ': : irS8 : 862 : 2.362 : : 1?99 : 931 2.550 : : 19OC : 17,700 ': 758 : 2.077 117 :' : 1901 : 750 : 2.055 : 1902 : 761 2.0S5 : 1903 : 733 : 2.00s : : 190U : 771 : 2.106 : 19C5 : 761 2.0S5 : : 1906 : 9UI+ ; 2.586 : 1907 : 1,222 3.3^8 : 1908 : 1,386 3.787 : 1909 : 1,413 3.871 : 1910 39.578 ': 1.653 1+.529 III+ ': : 1911 : 1,321 U.939 : 1912 : 2,095 5.72I+ : 1913 2,50U b.SoC : 191U 2,6Ui 7.236 : 1915 2,768 : 7.53^ : 1916 2,958 : 8.082 ; 1917 3.151 !?.633 1* 1912 3,623 9.926 : 1919 3,313 9.09c : 1920 7^,361 3,560 : 9.727 131 ': : 1921 3,591 9.833 : 1922 3,6b2 : 10.033 : 1923 ^,3^0 : 11.89C : 192U U,U22 12.2U6 : 1925 : U,670 : 12.795 : 1926 : 5,229 : 14,326 : 1927 : 5 MG : 15.030 : 1928 : 5,in : 15.763 : 1929 : 6,115 : 16.753 ': 106 ': : 1930 ': 1^7.995 : 5,71^ : 15.655 : 1931 : 5 ,SOU : 15.901 : 1932 : 5.513 : 15.063 : 1933 : 5.536 : 15.167 ■81- PLATE 21 i^ep J9d suo||e6j.o suoi||iuu ui uoi^doinsuoD ja;e^ 00 lO (\j 00 lO (M % c 3 o < ^ ■(— < / CO Q_ O Q. z ^-g ^ -n ^ \ < \ PTIO per per \ i ^v \ \ 2 ^ ro \ ^^ ^ \ D i_ — O CL \ Na Z r: CD CO u 1 1 ^ w O cp , ^ O Q. 1 V CC 1 \ UJ "^ i^ 1 5 .2 § 1 \ 1 Mill Gall J o o o 0^ o 00 o o o 00 o o o CVJ o 00 00 spuesnoLji ui uoi;e|ndOjj Aep jad e^ideD J9d suoneb ui uoi;diunsuoD ja;e/^ a: LxJ h- < § L_ O o o o h- U 2 Q 3 z (Ti < O (0 U U- o a Z z en < - H z 5 o _l _l a UJ 1- < a: O Q_ O Q. Ct Ij_ O O U I H 5 O o: o was acqaired, 1,000 acre-feet to Coronado \,-ter Company, and about 40 acre-feet to miscellaneous users alon^' the city pipe- lines. The total dr .ft on the city's system, there fore, v;..s 23,100 ..cre-feet in 1933. The capital investment, less depreci .tion, in the operative portion of this system on June 30, 1933, was 918,491,570. The investment in uncompleted projects, Sutherland ind El Capitan, at th^t time was $2,873,156, The City of Oceanside includes an Liroa of 6.64 square miles within its corporate limits, and had a population of 3,508 in 1030, It operates a municipally-owned water system consisting of four wells and pumps in the San Luis Rey Hiver bed, two booster punps, a five million gallon reservoir and a distribution system. The capital investment in 1933 was estimated to be about ^30,000, The system including lands and v;ater rights, however, v/as valued at 4^00,000, The draft in 1933 amounted to 926 acre-feet, of which about 25 per cent was for irrigation and industrial uses. The City of Hscondido owns and operates its o\m municipal water system and now purchases its water wholesale from the Escondido Mutual V/ater Company. The capital investment on December 51, 1933, iU.iom-ted to L?1C4,C00 and the total draft In 1933 v.-as 421 acre-feet. Public Utilities ana Private Companies - The Sweetwater Vater Corporation serves a grosd area of 14,000 acres lyin^r below the 16 5- foot contour on the eastern shore of San Diego 3ay between the south boundary of the City o:f San Diego and the Otay River, including the urban areas of liational City, Ghula Vista and Otay City. In 1953, 3,111 acres \/ere irrigated. The ph^-sical works consist of the Sweetwater Darr. and Reservoir, wells and pumps in the Sweetwater Valley and a pipe distribution system. The Sweetv/ater Dan is located on t he Sweetwater River near the easterly line of Rancho La ITacion. It v/as built in 1386-1838 to a height of 70 feet, creating a reservoir of 18,635 acre-feet capacity. In 1895 the dam was raised 5 feet and the storage was increased to 20,720 acre- -82- feet. In 1911 tlie darn was raised again and the 3tora{:e increased to 35,164 acre-feet. At the present tine due to silting the capacity has been reduced to 23,065 acre-feet. The present d;in is a thick concrete arch 95 feet high .-.nd 420 feet lon^ on the crest. ?iie spillv/a/s consist of siphons and an ovor- flo\. structure. There is also an ..uxili iry earth dam '62 feet high and 1,140 feet long B feet wide on top with an upstre;un slope of 2:1 and a down stream slope of 5:1. The capital iuvedtment, luss depreci-tion, on December 31, l'J33 was reported to be ^2,525,651. The present \/ater rites are $0.30 per 100 cubic feet for less th.-.n 1000 cubic feet; *0.18 for the next 1000 cubic feet; for C.11 over 2000 cubic feet, ;^0,06 for irrigation and .'pO.lB for all other purposes. Minimum ch.^rges range from :|^1.50 per month for a five-eighths inch meter to ^14,40 per month for r: four-inch meter. The Coronado \,ater Company,' serves tiie City of Coronado, the Otay Valley, and tne area between San Diego Bay and the Tia Juana Hiver ^sin, including the unincorporated coram'onities of Palm City and Imperial Beach. The physical vorks consist of wells in the Otay Hiver basin, p'Jraps and a reser- voir near palm City, a transmission line from a connection with the City of San Diego's system near Otay, an eight-inch submarine pipe line connecting v;ith the City of San Diego mains and the distribution system. On December 31, 193^, the capital investment, less depreciation, v/as .'^586,118. The Coronado \»'ater Company, incorporated in 1636, drew its supply from the City of Sm Diego mains until 1889 when the wells in the Otay Basin were sunk. Prom that time until 1J08 the whole supply w,-s furnished by the Otay wells. ?ron 1908 to 1916 tne supply Ccimo from the Lov/or Otay Reservoir but the wells were main- tained as cin emergency supply. \^'hen the floods of 1916 destroyed the Lower Otay D-i.m and the pujjping plants, service was m-iint-^ined through the submarine connection with the City of San Diego. Although the pumping plants in the Otay V-lley were rebuilt, the new Lower Otay -Jtm built in 1918 cut off former -83- lin,-s of seep .fc-e 'Jid since 1324 only -:.'DOut 22 percent of thu supply h .s come from the Otay wells. The rest has been purchased from the City of San Diego. Tae use, practically all domestic, amounted to about 1,240 acre-feet in 1333. The Fallbrook Public Utility District, a public ov/ned agency organized about 1924 for the purpose of supplying water in the town of Fallbrook and vicinity, serves a gross ^rea of 754 acres. The original plant consisted of v;ell3 in the vicinity of Fallbrook, pumps and a distributing system. The wells, however, v/ere abundoned because of deficient yield in 1933 and a new well was sunk in the sands of the Saiita Margarita River. The present physical works consist of the nev; well, a pumping plant .ind booster pumps, c reservoir in Fallbrook uid a distributing system. Aoout 45 acre-feet of welter were pumped in 1933. The c^ipital investment, less depreciation, on December 31, 1933 was The S'-Ji Diego County Vater Company owns and operates the Henshaw Reservoir loc .ted on the San Luis Hey River, it the lox/er end of V/arner Valley, The comy-ny is ; priv-te corporation and does not function -iS .i public utility. The reservoir has u capucity below the spillway lip of 205,581 ;.cre-ft-et and is formed by the Henshaw Dam which is located in Section 10, T. 11 S. , R. 2 E. The drainage basin of the San Luis Rcy River above the dam site has an area of 205 sq'Jiaro miles. The dam is an earth-fill structure with the spillway lip 107 fest above the stream bod. The crt-st leiigth is about 1,950 feet. The downstream face has a slope of 2:1 and the upstream face a slope of 2 :^:1 and is protected 'o^ a concrete facing. The overflow spillway located at the right end of the dam has a capacity of 37,500 second-feet, '^'^q water developed by this project is wholesaled and at present the principal purchasers are the Vista Irrigation District and the Escondido .lutual V/ater Company. In 1933 Vista Irrigation District purchased 6,424 acre-feet of water at .)17.50 per acre-foot. The water is rel<.ased from the reservoir uid runs down the natural channel of the San Luis -84- Rey Rivt:r tc the Esoondido ditcn through \vhic}i it is diverted to Wohlford Hcscrvoir and delivered to the raaiu c.uial of the Yista Irrigation District and to the distribution system of the ilscondido Ilutual \/atc-r Corap-aiy at the tuil race of the Sear Valley Power house, The approximate cost of Henshaw D.-un is reported to be .)2, 000, 000. The Del iJar Vater, power and Light Conp-iny, a priv ite corporation, serves domestic v/:ter secured from Hodges Reservoir to the residential develop- ment in the town of Del il-cr and vicinity. Its supply is purch -sed from the City of S'--n Diego -.nd in 1933 the amount used v/as about 123 acre-feet. U. S. Indian Reservitions - The Li Jolla Indian Reservation is loc.ted on the steep south slope of Pf.lon .r I.-Iountain -.nd ths at-nch lands bordering the canyon of the San Luis Rey River and comprises a total area of 0,329 '.cres. The irrigation system consists of a smj.ll diversion d-i.-i on Potrero Creek, wliich is a tributary of the 3an Luis Rey River, about 1000 feet of 8" pipe, a small reservoir and a pipe distributing system. It is primarily for donestic purposes and for watering small gardens. Tiie net irrigable area is bO acres, all of which v/ere irrigated in 1952. The total 'Capital investne.it is estimated to be $15,000. The Pala Indian Heserv-.tion is located at the old mission San Antonio de i^ala. The reservation comprises a total area of 18,780 acres, patented and withdrawn, in the San Lais Rey River 3asin# Tiie mission lands were v/atered by a aitch diverting fron the San Luis Rey River, which was probably built in the first or secoiid decade of the nineteenth century. This ditch is incorporated in thv; present system, which therefore may be said to be one of the oldest active irrigation systems in the State of California. The present system consists of an intake on the San Luis Rey River, the northside and southside laterals and distributing systems, fr.vo wells and pumps, a small reservoir, and a pipe distributing system for domestic v;ator for use in the town of Pala. -85- I The capital investmsnt less depreciation uqs about $29,000 in 1931. The systom serves a gross area of 630 acres, 587 acres being classed as irrigable, of which 400 acres were irrigated in 1933. The Pauma Indian Reservation nov; comprises three tracts of land, of 225, 12.5 and 12.5 acres respectively, lying wholly v/ithin the boundaries of the Pauiria Grant. It is situated in the San Luis Rey River Valley about 6 miles upstream from the tovrn of Pala. The irrigation project is virtually identical with the tract of 225 acres and has the right to the first 30 miner's inches of water in Pauiiia Creek. This v/ater is diverted and carried through the Pauma Valley Mutual "Yater Company's pipe line to a connection with the reservation system. The VTorks of the reservation project comprise a diversion vreir, a cobble and cement lined reservoir, and a distribution system consisting of about tTjo miles of cement and steel pipe. The capital investment less depreciation was estimated to be ^4,500 in April 1933. The net irrigable area is 222 acres of '.7hich 57 acres \Tere irrigated in 1932. The Fincon Indian Reservation is located in the San Luis Bey River Basin, about 10 miles above the town of Pala, and comprises a gross area of 2,314 acres, of vThich 720 acres are classed as irrigable. The reservation has a right to the first six second-feet of the full natural flo;T of the San Luis Rey River at the Escondido ditch diversion. This flow is diverted by the Escondido Mutual later Company and delivered to the distribution system of the reservation at the tail race of the Rincon porrer house. Agreements with Es- (^ondido Mutual Tfater Company and Tra. G. Henshaw also provide for furnishing povrer from the Rincon or Bear Valley porer plcnts for pumping and guarantee maintaining the tvater levels in gravels from v;hich the pumping supplies are secured to certain elevations. The reservation mantains three pumping plants in the San Luis Rey River Valley to augment the supply during periods of deficient floir. 220 acres :vere irrigated in 1952. No information has been -86- obtained regarding the cr-pital investment. Other Indian reservation projects frorr. the San Luis Key River to the Mexican border are smr-11, combined they serve a not irrigable area of 68 acres, of which 56 weru irrigated in 1952. The total capital investment amounts to about ^^9,200. I nd i V i du al Private Development . Almost all of the water development in San Dit-jgo County by individual enterprise consists of utilization of tne ground waters by m^ans of wells and pumps. A few ditches have been constructed for direct diversion of surface waters but in g-^neral there are no perennial streams oxcept in the higher elevations, and a reliable surface water suppl/ is dependent upon comparatively large surface storage. One of the fev; private diversions is the O'Neill ditch which diverts w.iter froni the S:>-nta Mirgarita River .t the upper end of the Sc^ti. M^rguriti Villey into the O'Neill Reservoir. This reservoir hus a cap-vcity of 690 acre-feet ind w^s constructed in 1883. The w.^ter supply from this system is usei for irrigation on v.illey lu],ds ne-r the S-^nta Margr.rita Home R-'jich. There are 14 minor dans owned by individuals and private companies in San Diego County, having a combined storage capacity of 890 acre-feet, and represent a Ci.pital expenditure of about ^160,000. Most of the reservoirs formed by these dams provide regulation for the irrigation and domestic supply of private estates and small real estate developments. However, a few of them are for recre::tional use. A tabulation of existing surface storage reservoirs in 3-n Diego County is shown in Table 13. Tne larger part of the water supply for irrigation of the valley floors is provided thro'ogh private pumping plants, while most of the supplies for the upland benches or terrac-.-s are furnislied by organized agencies. -87- TABLE 13 EXISTING SURFACE STORAGE R5SERV0IRS IN SAN DIEGO COCWTY Height of : : : Stream basin and Location of dam : eplllway crest : Reservoir ; : reserTolr S. H. B. Jc M. : Type of dam above stream bed, capacity, : in Totals : Ssctlon : Township : Range in feet acre-feet : : Santa Margarita : O'Neill 8 10 S. 4 W. Earth ; 12 690 : : Total 690: : San Luis Hey ; j:agles Nest ZQ 10 S. 4 E. 2 Tertleal arches 8« 3 : Henshaw 10 11 S. 8 E. Earth 107 203,581 t Total 203,584: : Aqua Hedionda i Pecheteln 87 u s. 3 W. Earth 99 200 ^ • Total 800: : Escondldo : iVohlford 5 IE S. 1 W. Hydraulic Fill 95 7,225 : San Dlejulto 16 13 S. 3 W. liultiple arch 41 1,128 : Total 8,353l : 3an Dlegulto : Hodges 18 13 S. 2 W. Multiple arch 115 37,699 : Upper 4 3. 38 13 S. 8 W. Gravity curred 8B 800 Lower 4 3. 38 13 S. 2 -,7. Gravity curved 81 60 : Green 36 18 S. 2 W. Earth 33 10 : Fairbanks 34 13 S. 3 W. Gravity 38 100 : Total 38,069! : San Dlago : Cuyaraaca 5 14 S. 4 E. Earth 35 11,595 Pir= Hills 13 13 S. 3 E. Earth 18 16 : ::i Capitan 7 • 15 S. . 2 E. : Hydraulic & rook fill 197 116,872 : Eucalyptus : 17 16 S. ■ 1 V7. : Earth 86 26 : Nturray Hill : 16 : 16 S. : 1 W. ; Earth 35 127 : Murray 13 16 S. : 2 W. ; Multiple arch 107 5,885 : t : Lily Pond : 16 : 16 3. : 1 W. : Earth : 17 10 : Miles IT • 16 S. t 1 W, : Earth 16 : 10 : t : Total 1 : 134,541: . Lus Chollas Valley 1 Lemon Grove 30 16 S. 1 W. Earth S5 g . Chollas 1 Cro.ich 1 Total 3S 9 16 S. 17 S. 8 W. 8 ff. Earth Earth 43 49 278 40 324i : Sweetwater : Monte Vista Ranch 31 16 S. 1 E. Earth 90 10 : Helix 31 16 S. 1 Vf. Earth 4S 190 : Sweetwater 17 17 S. 1 w. Thick arch 95 89,065 : Stilling Pool 17 17 S. 1 B. Slab and buttraas 16 5 : Keen Valley 84 17 S. 8 W. Earth 84 50 Total 29, 380 i : Otay : Upper Otay 36 17 S. 1 W. Arch 78 8,793 : Lower Otay : Total 18 18 S. 1 E. Gravity curved 140 56,381 59,114! : Cottonwood : Morena 14 17 S. 4 £. Hook fill ; 167 65,800 : Corte Madera 16 16 S. 4 E. Earth ; 10 50 : : Henry Jr. 8 17 S. 3 E. Arch SO 196 : Mary Joe 8 17 S. : 3 E. Arch : 88 135 : : barrott 82 17 S. 3 E. Gravity curved 148 42,899 : Total 109,080: : Total storag« Paeifle a lop«, Saa Diego Gov inty 583,275! 88 It is estimated that 18,650 acres were irrigated in 1332 from private plants. Utilization of Un-iert^Tound Basins. The utilization of undergrouiid storage basins has been an important factor in the water supply development in San Diego Comity. All major stream valleys have underground basins, which while not comp-xrable in extent or stor-ige volume v.dth underground reservoirs as may be found in other parts of the State such as the upper San Joaquin Vn,lley, the south co:-3t:'.l basin of Southern California or Vonturi County, neverthelGss, ".ro of sufficient c-.p%city to be of gr^;.-.t v.-,lue. The loc.tioa of the principal underground br.sins md their extent are sho%vn on Plate VII, "Principal Underground Reservoirs in Pacific Slope B-sins of Sai; Diogo County." Other srariller rjid less important underground basins occur in the minor stream valleys of the coastal a:lt and the highland area. Ground water supplies are also obtained in relatively small qu.-ntities frctn the weathered material or decomposed granite in the highland area, and from the tertiary and older sedimentary formations. The principal underground reservoirs hxve been developed by priv.to individu-ls for the irrigation of the bottom lands of the major valleys and by many organized agencies for domestic and municipal use and for irrigation of permanent and annual crops on bench or mesa lands adjoining the valleys. Many scattered developments have also been made utili:;ing the ground water from the minor valleys and from the weathered materials in the highland areas. Approximately one third of the total quantity of water used in San Diego County is secured fron underground sources. A detailed study of the geology and ground waters of the Vr-estcrn pvct of S;.n DiJgo County was m'.de in 1915 by the United St-tes Geological Survey :uid the results puoliahed in V/iter-Supply Paper 446.* ♦U.S.G.S. \Yat§r-Sups.ly paper 446, "Geology and Ground •/aters.of the vestern Part of San Diego County, Caiiforrtia'",' 1319-. -89- 5:;~TTT PLATE 3ZII In '^ater-Supply Paper 446, no studies were made of the underground basin of the San Luis Rey River which lies between the mouth of the gorge near Rincon and Pala Mountain near the town of Pala. This area and the side fills of the streams tributary on the ripht or north bank in this section of river were classified as Pala Conf?loraerates on the geological map in ^/.S.P. 446. A reconnaissance of this basin made during the present investigation indicates that a storage capacity of approximately 11,000 acre-feet may be available in the main fill and approximately 16,000 acre-feet in the side fill on the north side of the valley. Detailed studies were made during the present investigation of the Mission Valley and upper San Diego River Valley underground basins to determine the storage capacities of these basins as additional information has become available since the publication of W.S.P. 446 on the specific yield of alluvial sediments, and further information regarding the underground conditions in these basins has been secured frora the logs of wells drilled since that time. The storage capacities as found by those studies were somewhat larger than those estimated in I.S.P. 446. The estimated utilizable storage capacity of the upper San Dieeo River Valley from the Old Mission Dam to Gape Horn including the San Vicente Valley from Lakeside to Foster ;7as found to be 24,200 acre-feet and for Mission Valley between Old Town and the lower end of Mission Gorge, 10,500 acre-feet. Thile no detailed studies were made during the present investigations of the underground basins on the other major streams, a review of the storage capacities given in ^.S.P. 446, based on comparisons with the results for Mission Valley and UDper San Diego River Valley, indicates that, were the basins studied in the light of the more recent information available, and the fact that a material advance has been made since 1915 in the design of deep well pumping equipment, the utilizable storage capacities of several of the basins -90- would be found to be somewhat greater than that given in W.S.P. 446 and the combined storage capacity of the basins may be as much us 185,000 acre-feet. The extremely ujiequal distribution of run-off has been shown in Chapter n. Large storage reservoirs will be required to accomplish the seasonal and cyclic regulations necessary to meet irrigation or municipal demands. The expense of surface storage works is great, and after water has been stored th.e losses by evaporation from the surface of the reservoirs may amount to a large part of the waters originally stored. The underground reservoirs therefore afford natural storage space utiliaable in practioally the sane manner as surface reservoirs and with advantages in saving evaporation losses if properly operated, and in maintaining a high standard of potability. They are of especial value for reserve supplies in periods of drought, which must necessarily be held over from the previous wet cycle, V/hile their total storage capacity is a comparatively small amount of that necessary to fully develop and conserve the local run-off, the basins are available and at present only partially developed. Their additional development and use should be considered and more accurate data secured as to their capacities and rate of replenishjnent, when planning future water development of magnitude. No effort has been made in any of the underground basins of the county to augment their natural replenishment, and little accurate data have been secured on the rate of replenishment. With increasing use of these basins and with the construction of additional surface storage, artificial spreading grounds may be required or coordinate operations with surface storage reservoirs may be essential to secure the maximum use of these basins. At the present time the underground basins of the Santa Margarita River are being utilized for irrigation in the Temecula Valley, for domestic use by the town of Fallbrook and for irrigation in the lo\/er Santa Margarita -91- Valley. In the San Luis Hey Hiver 3L.sin, use of underground w:iter is beiiig made by the Rincon aaid Pala Indian roservat ions, by the P;.uma MutuAl Water Company, by the Cirlsbad .,Iatu:-l W:>,ter Company, by the City of Ocoanside md by m..n^' private individuals. About 1,500 acres are being irrigated by priv tte wells and pumps within the F:i,llbrook Irrig:;^ion District :jid secure their Wr-.ter supply from the rcsiduun or decomposed ^jranitt, of tiie F-T.llbrook Plain. In the San Dieguito River 3. sin, the Rconona, Irrigation District secures its water supply from the basin of 3;nta !iaria Creek, as does some private development. ?riv-.te pumps and wells arc operated in the San Pasqual Valley and in the San Dieguito Valley below Liico Hodges. Other private devel- opment has been mcide in the Bear Valley and Valley Center area and in Sscondido Valley. In the San Diego River Basin, the La Ilesa, Lenon Grove and Spring Valley Irrigation District has a number of v;ells and pumps together with a booster pump at El I.Ionte, which are used as an auxilliary supply to its San Diego River system. The Lakeside Irrigation District and the Lakeside Farms and Eiverview Farms mutual water companies secure their water supplies from the upper San Diego Bisin in the vicinity of the tovm of Lakeside. The City of San Diego operates two puraping plants in this same basin, known as the Lakeside and Riverview Plants. In Mission Valley the City of San Diego operates v;ell3 -nd pumps located near the city boundary. In Mission Valley and the upper San Diego River Valley, man;^'- private plants also secure their supplies from these basins. In the southerly portion of the El Ca.jon Valley, an extensive development has been n.ide utilizing water secured from the residuum or decomposed granite, which underlies that area. In the Sv/eetwater River Bisin the Sv/eetwater Water Company has developed wells and pumps in the lower underground basin below the Sweetwater Dam. In the upper Sweetwater underground basin the development has been entirely by private individuals. In the Otay B^sin belov/ Otay Reservoir, the Coronado -92- T^I V/j.tor Company- h:;3 wells :\n.d. punps and receives p:\rt of the supply used in Coronado from this source. Some private lands arc irri^jited from v/clls. The Siin Ysidro Irrigi.tion District secures its supply from Tia Juana River under- ground basin, from a well field south of the tovm of S^n Ysidro. Development has been m-tde by individuals for the irrigation of Ir.nds in the Tia Juana Valley. In addition to these developments of underground waters, many small tracts sc .ttc-red throu^^hout the county have developed reliable supplies in minor valleys from the decomposed granite. The 1929 United States Census reports 311 pumping plants having a combined engine or motor capacity of 2,634 horse power and combined pump discharge capacity of 73,430 gallons per minute for the San Diego River drainage basin. The 1929 census did not report any other drainage basins separately in San Diego County, but gave for the entire county 996 pumping plants having a combined capacity of 9,013 horse power and a combined capacity of 223,812 gallousper minute* Growth and Location of Irrigated Lands. previous to the completion of the Sweetv/ater and Cuyamaca water systems, irrigation v/as confined to the small and scattered areas in the various stream basins with snail ditches diverting the natural rvm-off when available. V/m. Ham. Hall, State Sngineer, reported about 1,70C acres under irrigation from surface diversion in 1888 within the present boundaries of San Diego County, includinf; 308 acres receiving water from the newly completed Sweetwater system. He reported about 1,100 acres in the San Jacinto Hiver Valley now located in Riverside County. The United States Census reports 10,193 acres as irrigated in 1889 for the county, v/hich at that time included part of Riverside and all of Imperial County. During the following twenty years the irrigated area increased -93- gradually to about 25,000 acres, with little or no increase during the decade from 1909 to 1919. V/ith the construction of the Hodges and Henshaw reservoirs and the formation of the Santa Fe, San Dieguito and Vista irrigation district^, the irrigated area increased rapidly and in 1932 48,725 acres were reported under irrigation. These data are given in Table 14. TABLE 14 GROWTH OF IKRIGaTED AREAS III Siil^T DIEGO COUNTY Year of census 1889 18;)9 1909 1912 1919 1926 1923 1932 Census agency United States United States United States California Water Conservation Commission United States Division of Uater Resources United States Division of Water Resources (2) Area irrigated, in acres 10,193 (1 16,022 24,994 19,880 24,996 46,346 42,510 48,725 (1) Includes some lands now in Riverside Gouiity. (2) Bulletin NOk 43 "Value and Cost of Uater for Irrigation in Coastal plain of Southern California", 1933. The extent and location of the lands under irrigation in San Diego County are shown on Plate VIII, "Irrig.,ted Lajids in San Diego County". The information shown on this plate was secured hy a field survey made in 1926 hy the Division of Water Resources and supplemented by more recent data secured from irrigation districts, water companies and other sources. V/hile irrigation may have been abandoned on some of the tracts shown and others placed under irrigation, the map portrays the general locations of the irrigated areas and -94- G^i-III PLATE 3znr OD 'I V I a a d IV I their relation to the tot .1 .re. of Sun Diogo County. A cooperrvtivu crop :.nd. irrigated land survey is at present being conducted by the Division of V.'ater Resources, the County of San Diego and the State Qnergency Relief Administration, but has only been partially cor.pleted (January 19o5). Preliminary data of this survey have been tabulated for the Tia Juana, Otay, Sweetwater and San Diego River basins and are presented in Table 15. Present Area and Value of Irrigated aiid Unirrigated Crops. A wide diversity of crops are grown in San Diego County. The large area of practically frost free l:*nd along the coast, in the foothills and the warm bench lands of the interior valleys allow the production of many varietias of semi-tropic-il fruits uid winter vegetables. Avocidos, oranges jjid lar.ons are the most important fruits produced, v/hile celery, tomatoes, md Irish potatoes -re important vegetable crops grown. Cauliflower, string beans, sweet potatoes, boll peppers, ps:.s and summer sqosxsh are c'.lso grown and marketed during the winter and early spring. Apples arc grown in the mountain district at altitudes ranging from twenty-five hundr-d to fiv-: thousand feet, a large acreage of gr.ipes are grown in the v,llays and foothills, alfalfa and silage crops are produced in the river valleys and are used for dairy feed. On the mesas alojng the coast, b;.-ans arc an important field crop and in man;/" cases grown without irrigation. A Ivrgc .acreage of wheat, barley and oats are grown, a great deal of which is cut for hay. It is estimated thrit in 1930 the value of land, buildings, equipment and live stock utilized in the agricultural industry in the county was about $92,000,000. The area and value of crops grown for 1929, 1951 and 1932 are shown in Table 16. Grov.th of Urban Areas. San Diego was the first land sighted and visited in what is now California by Don Juan Rodriquez Cabrillo just half a century after the discovery -95- • • • • tJ ^ C\J ^.n a> OA rH r^ ,-1- ro vx) r--kr) Lr\ 0) J- r^ r-- U),-!- J r-- rH in LP. cno +J ,-t J r-i LO. t"- r^ r— cr\ 0^ kxi Lr\ d *• *• » - » ■« M tU) BJ (—1 r-l frs _-!- \<-\ r^ WJ ^ C3 -H P 1 r-\ -tJ fH fn f-i H -^ ( Om 10 000 ^ LO CJA UD cr> u^ m J- ..-i vo.-i- U^ VD r-\ U T) r-i OJ r^ d cu CO rH -rH P tH fl -H u D .. 0) rH rH OJ \r\ rH > D iH . OJ tM f-H r^ ,-J- <^D 1^ r^^ ^ rH K> [■■"> rH|^, OJ T-i ^ O^ t 1— 1 -^ 1 ■■ 1 " ft rH r^ -i- 000 o.--t.ij- J- U tJ a CJ ai ^i- cr\ CTV J^ h— C/J £^ rH P^ lU Cj CJ r-i\r-\ r-* J- rHjU- OJ a •H f( 1 rH •H tin m ! ■■ 1 " Ph M CO rH LO i.r. CJ OJ ^a5^X) CJ U3 r- VDVO LTv LTi o o- 0-\ jd- ^ 1-- to r^ OJ t^\ OJ u rJ p 1^ t-- LC^ M. i to r— u fH r-H ••; •• " " EH CJ rH|rH ' r-\ r^ 10' , , • • •• «• •■ •• +» 1 "' c6 Ui •-\ r-\ CJ ^ 0^ rH rH CO LOO r^ W Q) OJ foj VD l^ LTN to ^ 1^ •H !=: r<-> OJ >sD r- >H ■H — !-i > r-A rH i-A •H ^H " * "1 " w -d ir\ u^ roo ro vr) 1^) Lf> r^.^t- rj • * ' r-\ rH > '• f! ir\ K^ tyj r--iio \r\ ^- r-\ ^ OJ LTl en r^ i-'A w r^ u? J- en OJ ^0 VO pi 0- LTv VO OJ ro t< •1 - •» (V •H rH OJ r-i OJ Jt fi >s § 1 §1 ^ •rH (U CO 5? PI PI n Pi rt CO bjl rH r-t CO Is d r-i ^--i >i !^ ^1 u •H +> cj CC (D a r: rH +» +> fH 40 -IJ +> n! 4J C3 ^1 rH 0) c^ c3 fn -rl (^0 P! cd CD a r,-; > %■ ^ (D Ph-H -tJ TJ FQ > > M ^ • H 4-5 +J > p3 fH •H (B •rl f-l CO in p.; (D 0) CO •H C3 t, tail iss als a p « ^^ C rH & & rH OJ g; rH ft; n +> •rt ^ c^ r; cr f^ (i; u ^ ti a rH ^ (1) A p ^0 +J bfl CO ^ p, 0) _ 4J ■H ^ W > & > •H !> :;3 CO ^1 •-D tl3 rH ■tJ rH PI -H r-\ ^ -H >i.a Q) 0) n (D ^0 cd Q rH cb a> cd - CD r-i in (3> rH +^ W ^f" r-{ c^ w ^ to ■^ CD in to CO r-\ CO cu P< '. J CO ^ O UT CO a» ■^ -\ , o o o Oj o o «U o o o ■* o ■^ •iH iTj rH t>- c- 1 W 13 r^ rH rH a m r}< in o o 05 CD to o .H P4 r-{ to ^f to rH 05 CD s CO 0) o lO in lO to •H fH •1 •H fm o rH M to o H a\ Oi H CD O t> (D O to -* 'JJ to o ft r-l o in c- c- o CO w n •H •-\ r-i •H u > '* •• '• ^ •H 02 "O o D- N «5 «t/ W rH CO <0 O O) ^ w 13 e CO Ol ^ (U O -H X O ^ O O F^ O ra o OJ o O O v;* in O CD o t- CO 00 o c- w o t> CO -a to o c- o CO •t »• •s o H rH rH o f> . t5 .. .. CO o to in ■<}< O rH W ■* O CO Oi in LO ? o CJ3 rH c3> c;^ in ■* '^ o f-( rH in en in LO +a •t » M ■rH •-i ^ C} O HJ -^ M o m 03 •H 03 ti c u C! •P +i iH o O o to fl. >i +> tH -rH o 1^ y ^1 Q >, TS ui •H +J O •H o f^ w a ;h ■P -M O u (U m p .^ o o (0 w tH +> E-< o r-t »J o « fl CO --' to CO •H w >> O f;i) w P CQ pq o +J Ph rH •r^ tijj en U <0 bD > a t» t> CO O -H O O M 03 t-i o •ri !jo :r; f-i o K CO 03 a a> >> c; >i ffi C3 -rl ^1 +> U rH 03 •H F-i 3 o d •H Pi (D M -iH (0 CD CO M ^ •p c-1 o ofH^i>i p)CO><+^ ■P (I) H :'J 13 5D CO o U B CO o 05 o o CO o o ^ r-\ (13 =) CO HO tlO CO C 03 CD W S p ft rH H ^ CO O 6D 03 +J O f» -P >, O u ;C •H ■HCaOG CPrH O CO 3 ,Q CO (D -rt 03 bo O C CO (a o CO pq r-i CO M CO »-; a % fe o o s CO Ph o « o p^ o § M o M P^ M CO CO • • •• -o ei r-i to r> ■^ CO tr H tc w OS o O CD CD • • o • • •• CO •^ c^ Q) CJ to lO C^ C^ CO C^ 0? rH rH Ti c^ O tp o r-l o> CO at en rH -P to iH to r^ Tj< t£) ■^l > t>- CvJ M » « •> in N t/-j in ^ ■^ O -H o in IN r-i - ''' Pi 1 • • •• .. 1 O CO o O O O O (~i vj* c^ c "*■ o o o • • • • •• o to o •H to to ■^' CO M' t£) r-i 1 w d ca a o r-i ^}< 'D tD * .,- ^ 1 r-t (f-. O o cri t> ro O C\^ O c^ ro o m o o o o o o cn r-l w w sj' to CV w o o CJ Vh w 'J* CO CO c^ iH ■< 1 T3 M o> «r w o o o o m rH o u'' O O to o 'O o N r-( ft H i-H to fO ^ * Q) O ^ r-i lO ■x> rn to •rH h •• ^ CO (U p. P;H O .. .. r-H , H rH ^^ ' ' • ■ • •* en ^ to OJ CO r-l O W C- CO CJ> CO OD rH «D OD O rH O o to o o c- o c~ no CO o a, OJ CD 05 o> -^ CO c- rH r-i 'O c3 d ? P W W rH O ,-t CD -.0 'l' rH o •* st< •H Ph Im w ri o ^^ V# V* 44 •• ■• 4% CO c" d" " p. w O lO o O O N rH CO O O o Oi o o o o o o CTl o (D •<1< '^ rH to •* ■^'^ !-, d ^ w C-- P- o ■H t3 (D > A. •• «• •• «« .. 4. K '* "■ ■ •p to -a W d c CO i-l CO tD o fT> cu CD po in o r-i c^ w to to o CO o in CiC O en 73 !D 05 rH lO CO ■^ 03 in m •^ in •o w •H d ■TS Ph rH rH .-o r-i in '■O o f^ XJ 1) (D ra ^H ■H .> s x; r-i r-i ■H •H a - 0» UJ rH O UJ o ro << CO 3 Oi to o ifi a> r-i a o in <0 O rH O o o r J Pi .O [N rH rH rH ee CO O o o m '.0 w tO %(' -p H rH rH C CO "^ rH w CO rH CVJ st< t> -/-I •« a^ C3 •^ w co" CO ter Co. ; strict i vation i ation i Water Co, ; ntain ; n District ; er Co, ; •p o •ri Pi -p ra d o CO o o •H d (0 -H Ph > rH d O -P o rH •> Ph M rH -P a (0 CO CO d Pi O CQ 0) H CO 5J •n (D d •rH CO (0 -d ■P >> O Ph C T} ,-t M C O 0) +a Pi S .M rH n P s ? CO (D tS Pi M d CO o o o TJ O O 73 S O 0) o =^^^ d M P» I"q O W CO Vl O H f!C H O « rH Eh d ■r-H Ph ,Q O Pi Pi rH CO A^ CO c * o CO d (B ^ d) to O CO 0) ^ O S ?> rH P> •rH CO tH ■rH O T^ O S e F- r^ ;> rH >> f> o o d o w d 3 d O rH O Ph -P o O rH O I^ o o ^A to -rH .H tr m j2 CO ^ or -H ^ ^ >» ■ ^ w > « (1h Ph «jj (XH *j! O O «J P c^;" * C\J o to vO |rH i ■■ c^-' ■■ r-H T3 -r-t CO (E W Ol o to 1 "^ "^ in D- in w o ■* 1 'O CO CN o 1 >* 1 **■ .s ^ . ^ . ^ ^ . O P< CO fH rH ';»< no UD to o UD CO in co" IN rH to LO E-H O (D CJ ^ !h CO O CO ■ • ( r-i IrH rH 1 "* 1 -d * ■ • • • • " ' ■ • • • • • • < ■ 1 rt 0) r-i rH CO ID a> C7> O (N cr» in CJ 3 -p m CO !> UO o to -* CO (y> c\i o OJ CV to to d ^'' pl c^2 Wjuj 1 ■* VD o tfl o C-- c^ IN CO CO ^. CD -H H 1 iH to 1'^ to" c:)* o' u.-) m O co" in 1 - 1 1 '^-^ 1 -P fn O r-i r-i to E-H -H CO " ■ • ■ • * ' 3 O s_> o Ifi O lO O tD <£> O o in o in to 1 -P >> 1 c^ CN I CO ! P. b 1 •^ . o t i 1 .. •? .. .. 1 1 1 ; " '^* i ■■ ■■ "l '" « & CO CJ> tN ' [> \(0 cn CO'W CD O O 00 t> 02 & 5 -H "* ' S', O- CO to tjO CO o ^ ^- CO in ^ O rH '^i' CO N "* CO tt) rH in c- w IN tif ^ CO t^ O CO C\2 co" OJ ^^0 f-\ C\j" CQ fH o M 1 CO .. .. I •• •• " * • • • * > • • ■ • ^ o o o N to CO cn o o o cn in 1=1 :3 rH C^ £R to CO in CT> << O IN CO in tN •H -p cn ■^ CO c:) ^ r-i rH r-i ^ CO CO ID to cri •« •- •» tO r-i |rH ei" P4 .. '^^ o to o CO ■■ in IN CV! " in ' o (X) £N a CN t) CO C\3 O w Ol CT. r-i in IN cr> O lO t> IN O r-l Ph ID CO ^ ^ rt< CO ^ C\2 to w cr> o w -a .. 3 3 « O CO 13 tJ to o in in c- (N (S ts w 02 lO r-i 3 ^ r-i r~i C\2 w in TZ) 0) W CO •H > -H ^ O ^ 6 O O rH ^ P O O to o ^ a coo ca c w o ^ o o o OJ 3 U2 in in ^ -P •r^ 1 O ^ ^ >. i 1 i g o CO •r^ . to , +j a to ^ fn to C -rH -rl (0 -P O to K -U (D rH OJ C H O rH rH t> rH CC -P -P to ■p to cd c3 ri rH -P O CO -P ^1 CO CO +' •-H W3 O C H^ 4J •H U CJ v-'J o o 0) 13 =: O ^ ft -H +^ o o O m O > H u ^ > ■p +■ r-i •i-t ;h ^1 CO %^ -rH > •H O fH C M +i to t/j -o i « l| fH (3 O u c^^ « rH CJ +3 (x; cO -H -M ■H <1> CO p 0) 0) o to fH P, ■"' •rH s 0) 5 4-= ^ •H > O CO > O ffl > :=-; to O fH O t^ +> 3 O CO W O rH s O rH •H O ■r^ O ,-i o CO Hi ,□ •r^ ^ 0) -p ,q (D n ^^ CO P rH C5 O o to ^ Fh ^^m +* •^ W CO -ij h^ w m •iH & ' Eh 1 o CO CO • • ■97a- n iH {■"o; ■■ 1 e:i P3 u3 00 ^i< c^ rH N ^)< 00 X) -H ^ CO -( rHCMCOtO'^COtOtO CM to r-H 05 03 tN W ' "I o o o in CO •^ in r-{ rH " ■« M *> « *k ff« •« •« +» p. CO f-l rH r> CN -i* CO iH (^3 CO CO r-{ 0)0 rH tV to t- Eh fH fn CO O CO ',' ,^ •• •• 3 +3 m cn CO C\J O- O H o o o .o iH (y> en ^ o o CO <£) O CO 'i< CO p c- C\2 to 1 uD in >* 10 «£> in r-j M O •* •» 1 - « - •l M 1 ""^ 'i3 <£> W CM r-{ a^ en • -P fn O rH N CM tn t:) o u 1 03 Eh -h C3 W ', ^ o o CO O O CD O O O CO H '^ ^1 'i* ai 4-5 (M C\2 to a» ■* in tjD to i S t; iH CN 00 rH 0) H t W rH .... rH CM •a . j -a W 1 1 0) ^ lO t> ^ CO O Cv o o o ts IN 'i* CN »-'■-. > o a> in Ol '^ CO CO to ■vfl in c t-H O fH rH n-i t> CO cr> lO 'dl iTi 0) w f^ O H ^ •• •* •> •» •» «« 03 •=•< • g' ^ r-l rH W rH in <£> >* ^ rd 03 rH Cr> O rH rA CO CJ t H c ■P o a- <£> sH cr> UD CO CO •H w 1 ; •t •« CO 1 1 rH oT to IN P< ^ cq" .. ^ i . ^ P- ^ rH ■■ o ya o AI CD o c:' -ii CO IN in ^ O -d CO to lO en lo U3 (.a H a> r^ 03 U rH P. in rH ii^ «3 rH lO ■* <-\ (J» •H t ' ^ 0) o n •> «« ^ •M ^ n rH CJl rH CO co" 4^ o 73 P=4 o iH r-l to c_^ 0) f4 0) " ii m I * * •• o 03 o p^ o ; o Ci o o o o o o to to 4--' c"^ M 7i O Cm t3 •H fH M cO M f-l ^^ --) t-^ ^1 . 'd 0) CO ^ d 0) o 1 CO CO o cr> o o o o t>- in 4J ' s p w i CJ l3 en LO [N ^ 00 ■H 1 rH in IN IN UJ .-, 1 03 1—1 1 •rl d to" 'd 03 o a^ C-0':i'OOOC\2CO in C-- CQ s o cd 13 S :3 01 cd 1 1 [N CO CO !N IN CM TTl ^ ^ ( -* ID Ci S ,_-_; 1 'd 0) « .G 1 ^ i 1 1 ■d 0) ■ *"' 1 « M o ' > o 1 1 P o ; j •H fe- I •• -co •• "i 1 1 j * ■ ' * " 0) ci o 1 1 1 o CO O O O O O O C5 C.J 03 M 1 ^ I fH Eh +^ 1 ! -t^ ' •H ' O M i ^ 1 I ( ' fH 03 .. j 1 1 M 1 I -p '— CO 1 W 03 M 3 1 ' •H 03 03 CN 1 1 fi ^1 rt -P +J -rH 0) f-1 cr> u 1 1 o O 03 Qj 40 .H -rl '^ -d 1 t i s fH Q >■> 1 * 1 •H 4^ 03 •d f ! o U 03 P! fH 4J -H fH ■H -■d 03 IN (D 03 c:\ -M c CO a> c 03 •rH 4J Eh 4^ •iH o « S cij -- •. 03 rt !>j bO 03 +J CO ' ! 03 c; 03 -H -H 03 frq --CJ C;0 M -H "d 4J -d 03 rH en ! TO ' P! r! > >■ CO -H Q n •H ^ f 0) o I o ■H bu W fH fi:; 03 , ^ -3 to fH >, ' ■ *^. « •H fH 0) M -H lO 03 CO 0) en ■" § i ( 03 w ! 1 o fH M ^ :3 CO ,y 4^ id M ^ 0) bj ii (4 03 1 o ; 03 ! o -p 0) I CO ■H ; ; H^ r=H 0) 4^ so ::a 1 1 1 •H •H M c3 TO ,0 c3 Cii -H 0) 1 1 ^ 1 o CO « <■; CO CO CQ 1 1 iH 03 ! o s £3 CO 1 1 a ai y 4^ 1 4* «• t 8h kJ CO >A CO P -97b- T3 O 3 +-> C o o in s § rn CO 02 a Eh CO !>^ o o o o w l-l H CO CO o c o (in o e; o o M |i) t-H CO •• ■« i: •• •• .. .. •• •• t?5 ;4 rH rO"^ Nj<'Ti-j o lO C- W rH C^ i-l C^ in 't" -tJ fc ■♦J p. W W 00 o ";:' « «o rH ^^ O 33 o • * * •« •k •k •• •* Eh •r-t W tH W ^ tp co" in o 05 " LO u.< p, rH CD r-< rH Cvi (£3 >. rH r-i CJ <-< 03 "t w CO 3 CJ, o rH (D rH O w rH 01 rH £0 oc O ^-i f-t m •« K •k •k ** •• » 1^ O 7-t in c\j T> r^ CJ in 03 Pa o rH -J* c B V, o o i-i .. w u oooocoowoocn .:; .. ^. Q O O CJ ^ c^ u CD t> >«< o w H ?0 •-< "^ ■* •a 3 rH 0» ft C) o ■y rH (U +J •k »> » ^ ■(J OJ rH CJ u. ^ CO .T> CO r-i, tu P. "• ■ • "• • " ' " .. ^, OO^HOC^OQDOO^ 00 sr o c^ O ^. a <-! l-{ _; " " .. ^ ooooooinooo L': " o o o 6* " ." rH ^ 03 l-< r-i r^ ^^ CD o ft 1 (D 3 O ^ Ih • o o^coo«owooin N " o 0*^0 ■■J* " ■~c CO w W D- rH c^ c~ CD v^ o «n o c- c^ c M ■r-( '-'I r^ i ■* ^ o ot^ooc-o^ooin ^ " :0 O «ft o G> " " i' 03 -a n CO CQ C^ o C\J CO in 'X? r-l 3 CJ tJ o CJ OJ CVJ <# Ol O ji T3 fH »% •k •k 3 0) a r-i rH rH CJ TJ « ^ •H ;> •^^ t) o •M a fH a O o 1 " .. ^ ooooooooo o " O o o c .. ^ ilo CQ !L0 g +J 3 o • • -p ■p d o y o '^i O -tH •H >. I • M fH c 0; o +J C fn +^ • •*J d Pi o O O a B: += f< 03 (33 (D f- c en o •H fH p. rH 3 O +^ o •rl 03 §' & O 1) fH ffl O -rH i: fH •rH rH CO. 03 cu 3 n +^ r- O S) -p CO rl r^ C! O 03 -P .■^ t3 F» CP +^ p: •H fH a o C o 3 a ti; rH -I o •rH « S HJ .H fl 03 T> •H 60 ■p n o -s ffi e< tH ■p ii< o p> -p •Pfl i5fHrH3C-H H fH rl m •H 3 C0C5C:>»fHiHrH-PraO3q « 3 fH t) W ■a CO ffi ^ tiT' tH .-p (1) O M 03 3 C3 C H •H T5 •H rH 03 03 S O cr .-? •p t> M N -P H -p 0) ^ % •r^ (D 3 -r-l :^ c! >» o f-,c "3 rHriiJc: oqj-p f. e ii rH Q -P fc-^ •r-t ^ b ^t a -.H l-H r-H>SOCQi.:i't-lOE-H 6£ H O (^ "H E-i c e t-H +3 -a ;=! fH ^ o fH .tH rH CO 03 d ■rH O +=OBa;>rH?'rH>,f> ^ O 0) rH ?• -H CO '~1 3 o tQC330rH0fH-P0 •H th ct< a ^ ca j^ d -H .o o rH O Z^ ;:'! hJ| 03 d -:> ^ -s ^ >s r-i " w >KeLiAH-al(iH«<)00-a5 ■p <=: P.H << O fH 9 • s CO c^ .. .J .. ■ • -97c- W ••■'•■ •"* . V' i . .. .•;" "i*: ;i ;.v »• •■ •i. VT) 1-^ • * • • * * * ' U) CJ • •• • o ■ « • • • • . ••v| •• OJ CJ CT. o cr> LPv 60 o r^ •k ** mn •« *• a> VO cr> cr\ "S CJ CTl to s in i-i r-H CJ >X) iH ri ■k •* ■« •« > CJ cu r^ r-l ■ee- -^C\J I— { o " " * o r-H LO, vr> ir\ o V.O f — CO n r^ -d- to LOi u^ - 0) •« " •k ^ •» td ^i VD o ITN CJ ITN o; o I-H 1-H r^ vri Fh n! rH I-H <3! ^ — . C i:-\ •H ^^ .. ^ ' to ' ir\ ' 6 r^ r~- U-N CJ o IC> t-i VX) >^o o jit iC\ VD CJ J- CO f:^ t^ o cr. cr> CJ i-H UJ CJ CJ LTv r— a ■» •» •«■ *» ■• > I-H ^ J- r-H i-H I-H '-^rH -«> CJ r^ 1-4 " " 6 ' 6" ' 6 " 6 o u> r— K>i h~- Lr^ CJ - o rH r- CJ o^ r-{ ci U •« •» (D U r^ o r'■^ r-H cr\ u a to rH K^ CJ <■: ^-^ I-H fl J- ■ H — ' .. " ^^^ J- vn CO CTl I-H r^ CJ r~- CJ r^ O J- C5^ to ir\ Jt ViD LO f-H ^-^ I-H r<-\ vn CO Q) •k r> •« »» •« •k »\ •* r^ LO to V£) o CJ r-- ro I-I t^ r^r^ ^O VX) o CJ n3 rH r^ CT' '^ ^_ to J- K^ -«?• r-H Lr\ CT. '--Cf^ -ee- r-i - ca J- J- V.O o VD ---^ r-H 1 Cfl r-H f^D ^ 0) ■d nl CO n5 c ;=i § +3 C! fn o O ■H O m -d 4J 0) Q) 0) 01 •^ o 01 h .c; >j f\D CO ,^ 0) +> cS QJ Ih •H o o W k . (iH ^ o o o 0) ■H O 01 03 0) Q) 0) Q) • ^^ U OJ +3 +i a o ■•-> (D o tH 01 01 u rt cfi •H ',ted : Assessed ; : valuation, : : 1933 : Popula- : tion.per: acre : : Chula Vista : 5.4 S,669 1911 .: J : $2,749, &54 : 1.12 : • Coronado i 1.6 t . 5,425 ■ 1890. : 5,410,770 ; 5.30 : : El Cajon t • : 1.1 . 1,050 ! 1913 : 439,850 ; 1.49 : : Escondido 1 i i 2.9 3,421 1888 ': 1,313,457 < 1.84 : : La i,Iesa 3.2 i 2,513 1912 • 1,630,895 • 1.23 : : National City 4.6 7,301 ! 1887 J 2,534,095 2.48 : : Oceans ide 8.6 ! 3,508 t 1888 : : 2,449,927 . 0.64 : : San Diego 5 ! 100.0 147,995 i 1850 • t 99,184,445 • ! 2,31 : Summary of Present Utilization. Major water supply projects have beezi constructed on all the principal streams tributary to San Diego County with the exception of the Santa I.Targarita River. The total capital investment in dl v/fiter supply projects in 1933 was valued at •1^33,627,000. Ten surface storage reservoirs hr/ine,' a capacity of 5,000 acre-feet or more have been constructed as well xs a number of smaller ones. An j.re \. of more than 186,000 acres is included within the service areas of organized agencies, and a tot.tl irea of approximately 48,000 acres were irrigated in 1933. Approximately one-third of the 75,610 acre-feet of water used in Sun Diego County in 1933 for consumptive purposes was secured from underground sources, while .ibout two-thirds was supplied from natural run-off or surface reservoirs. About thirty percent of the water was used for domestic and municipal purposes and about seventy per cent was utilized for irrigvtion. ■100- ■ -TS-iii i5-IIi The largest w.ter supply system is th.it of the City of San Diego which represented aa investment of 1^21,365,000 on J'one 30, 1933. The system in addition to supplying the needs of the Cit^ of S.Ji Diego furnishes v/ater for irrigation ?j\6. domestic use outside? tho city limits and in 1933 supplied a total of 23,100 acre-feet. A summary of the d-.ta showing the present water supply development of San Diego County is presented in 'r.ble 18. All estimate of the safe yield of the existing water supply development in Sr.a Diego Co^Jlty including both surf^ice .nd underground supplies his been m.ide i-nd is shown in T.ble 19. The safe yield h.-.s been estira.ited on the bisis of a full supply v.lth no deficiencies. \/hile it may not be considered necessary to limit the extent of the water supply for irrigation purposes to a one hundred percent supply throughout the most severe drought of record, it is probable that any supply not meeting these conditions will result in a much higher deficiency than planned in the last years of such a drought, due to the inability of the operatiiig maiiag-eraent of a system to reserve sufficient supplies to meet the demand after shortages begin to occur. For example should a drought period occur, it vail be difficult to restrict the use of water. -while it is available in a reservoir, as it is reasonable to expect that the succeeding winter will produce run-off in sufficient quantity to relieve the emergency. The total safe yield of existing developments in the County including the recently completed El Capitan Heservoir amounts to approximately 79,000 acre-feet* -101- o o n CO EH rH (^ O |il H-l 1- (i: ^ > EH fJ >H M Pi ^ w « F^ M << S g jV| ra (11 ■ ■ o O o o • • ■ o o o HJ VX3 r^ u^ 1^ ^ o rH 0) J- i-\ K^O ^ CO rH VIO ** o •• " •* ■« 1 0) rH O rH vx) J- rj lr^ r — O -r ^H f^l Eh o 1^ rt '^ rH ■ • *• • • * • • • • - +> l^ *" d ' d o " d CJ r! o Q> -H 1 m ijn 1 o ■'" •r) J~3 0) d> 1 •* -n-_ 1 60 r-i Ti IQ 1 rH h- CM rv^ •H Q> S.1 2 -H 0) J-( r-i CJ rH o o r Q cfl i ^ ^ G 4» " O OJ " d "§ " d 60 "s 6' o d ^< o •rl ITN iH t~- cr\ CO r^ -d^ Q) 1-a t>H r^ O r<^ t^ CJ ^' ■■J G 1 rH rH C\J LT, r: •H -rt O H " 6 " 6 d Q " d ' o' " d O o O o o o Q o 1J tJ U5I CO o I-— q CJ nJ Q) r^ LTn r^ h- J- rH rH 'Xi CJ CJ rH > C rH r-< rH CJ o to fL, .. ^ " 6" ' 6 d " d * d o o 0) - CI o O O o o o o CTi -1^ r^ <^ i^ MD (\j vx) r^ (U 'il)0~> O ^'^ O K^ cr> f^ — U •-) rH «3l !h nJ ^ rH r-i ..tl- f^ C; G ■rl -rH ■I 4 *» " Q O ' d d ' d * o '" o (.1 o o o o o Q o 4J o o q o q O q rH C in p v^" ^^^ cr\ CO r-- J- r— . n3 (D (u ;^ CJ LP, CM U3 Lf^ 0^ CJ +> S -4^ r^ to O r~- rH t~— Cd •H +3 d >=I^ * •» " •» 2- ^ ^ r-i en r<-\ r-i r-i K> f^ r^ C(J G G- G -H •rt w 0) 6 o ' d o '8 ' '8 ■ ' d o d o " d Hi d - 0) VU C\J r-- OJ CJ r-i CJ t/3 ^^ d U O (D 0) ni ^ W 5.1 ct. d CO rH Cfl pi -d •H > •H -d G •H CO ? o ■H o CO u •H ^ +» CJ ■H (D a ^ 6 •rl (D 4-5 •rl (U +> o o ■H K? § ^ M ji > << ■rl f-i Id •rl fn P. 'd Q; (U r-i (D § CJ t*i +3 +» •H W o f— ^ s £? cd +3 in HJ o ,o tJ ■rl ^1 fi a '?.. G fl • ■ > . n »-H HH fL, -102- TA3LS 19 ESTILIATEI) SAFE YISI.D OF SXISTIWG \/ATER SUPPLY LEVELOPI.fflllTS Ilv SAi< DIEGO COUIITY. • ■ • * t Strean basin < Estimated safe yield, ; in acre-feet. : : Santa Margarita River i : San Luis Rey River ! : San Dieguito River : San Diego River : Sweetwater River : Otay River : Tia Juana River ; 1,600 : 28,100 : 10,100 i 19,600 : 2,800 : i ' 4,200 : 12,600 : : Total ; 79,000 i -103- CHAPTEfl IV WATEE RSqUIREIffil'JTS In San Diego County the uses of water include domestic, municipal i irrigation, power development and recreational, of which domestic, municipal and irrigation are of first importance. The use of water for power develop- ment and recreation is incidental to iti3 use for either municipal or irri- gation purposes. As San Diego County has a large urban population, the use of water for domestic and municipal purposes is large, and amounts to ahout 30 per cent of the total use of the county. Irrigation water requirement is the amount of water in addition to rainfall that is required to hring a crop to matiirity. This amount varies with the crop to be supplied and the point at \7hich the water is measured. As related to the point of measurement, it is designated by the terms "gross allowance" and "net allowance". These items are defined as follows: "G-ross allowance" designates the amount of water diverted at the source of supply. "Net allowance" designates tlie an:ount of water actually delivered to the area served. The irrigation water requirements of California lands were studied several years ago and the results of the investigation published in a pre- vious report.* Additional cooperative studies for certain crops have been carried on in San Diego County by the Division of Irrigation Investigations and Practice of the University of California and the results published.** ♦Bulletin No. 6> "Irrigation Requirements of California Lands ."Division of Engineering and Irrigation, 1923. ♦♦Bulletin '+89 > "Irrigation Water Requirement Studies of Citrus and Avocado Trees in San Diego County, California, 1926 and I927 1 "University of California Experiment Station, 1930. -104- I- The investigations also covered the monthly distribution as well as the total seasonal amounts of water required. As the c-.vailable water supply in S?.n Diego County is limited and cosiparatively costly, efficient irrigation practices are used v/ith a correspondingly lovi use of water. The average net allov;ance has been found to be 1.25 acre-feet per sere. It may be assujaed from existing prac- tice in the county that for all future developments of magnitude, conveyance and distribution conduits viill be either lined conduits or pipe lines in order to minimize losses. Therefore, an average gross allowance of 1.30 acre-feet per acre has been ess\imed as the amount of water necessary to divert at the source of supply in order to deliver an average net allowance of 1.25 acre-feet per acre to the area served. The monthly distribution used in studi.es of San Diego River has been modified slightly from that shovm in Bulletin 6 in accord- ance with monthly demands in that basin, and is shown in Chapter VI. For domestic and municipal use, it has been shown in Chapter III that the City of San Diego's consumption of water per capita per day, has averaged about 115 gallons for the period of record 1900-1933. The average value of 115 gallons includes unmetered uses v;ithin the city limits and distribution system losses. This average value has been lowered by the felling off in per capita consumption in 1930. This may be due to the economic effect of the depression. In estimating future requirements a value of 120 gallons per capita per da;/ has been used as the gross allowance of water to be diverted at the source of supply. Estimated L^Eiximmn Safe Yield of Fecific Slope Basins in San liego County . In order to determine the adequacy of the local water resources to meet future water requirements, an estimate of the maximiim safe yield that can be developed from the run-off of the streain basins of the Pacific slope tributary to San Diego County has been made, vNliile in this investigation it has been possible to make a detailed study of the complete development of the -105- San Diego River basin only, by use of the relations betv;een run-off, storage capacity and safe yield established on this stream, from the analyses of the safe yield of existing reservoirs in the county, cind from availf.ble informa- tion on potential reservoir sites, an approximate estimate may be made of the amount of the mean annual inin-off v/hich may be conserved and regulated to fur- nish a reliable water supply, and of the storage capacity required to accom- plish this. In Chapter II, Table 8, an estimate of 302,050 acre-feet for the 46- year period 1887 to 1833, is given for the average full natural run-off of the Pacific slope basins tributary to the county. Of this amount 246,950 acre- feet originate in the principal stream basins above the lowest gaging stations while 55,100 acrt-feet is the mean seasonal run-off of the minor basins. San Diego County is especially fortunate in having a number of po- tential dam and reservoir sites for surface storage well distributed in all of the principal stream basins and in many of the minor basins. In Table 20, a list of potential surface reservoir sites is shov.-n. Other sites nay exist. V/hile data is not available on all of these sites, many of them have been inves- tigated by various agencies and sufficient inforaiation is at hand to show that the storage capacity required to regulate fully the run-off, may be secured. In this investigation, geologic examinations v.'are made only of the dara sites of San Vicente, Mssion Gorge No. 2 and Mission Gorge No. 3 reservoirs in the San Diego River basin. Therefore, the suitability of the dam sites of the other reservoirs shovm in Table 20 is unkno^vu, and geologic studies and ex- plorations of them must be made before it can bo definitely dett^rmined that satisfactory foundations exist at these sites. There are also undergound basins v/hich may be utilized, and in many of the highland areas a sufficient depth of residuum or decomposed granite exists to afford some underground storage. -106- •X3 CO >> ■--" +^ o a) -p a) c> S' •H 0) vj< O 'CJ V-. u CO (B 1 (T)' o f^ls in <0 +^ flj 0) ^^ iH I O ^4 fa, — - o CO Id !-l 0; O Tl -P cd cu pH a) fc" CO o p: o o CO CJ CC CO CJ" -H fH CO CO P, •a; t3 J3 ID •P •M W e _- T) IS &i i;-! o CQ • e in C5 • •iH CO -P - o o o o (jToO in o H o o o o lO ^ M VI U3 in (X) CS so (^2 o o CVl cvT CO o O o o O c> oo to rH » C\2 to tN in 00 w rH to lO O w en •* rH CO in 'XI CN o CD IS r-i CO in •^f r-M CO in r-l PJ O CO to o to on in o '^J' '^ •^ CT> IN lO O CO 00 ^ t-l ■* rH to CO rH C^J >* iHtOTit'ct' cjt'Jco {^Jr-^r^r^(^2 cvjWrHCvjoa cocvi • • • WWW ^ to w CO CO CO CO CD CO cr> a> CO CO C/i o o o CO 05 Ui CO CO c\2 CVJ (^a to CO rH rH r-H rH rH CO CO 00 CO CO CO 00 ■<* in •^ in vD in lo r-^ r-i r-{ ^i ,-i rH rH a> CO CO O !> CO O -^ C\J C\5 f-i c lO CVJ OJ i-H ■# CJ to rH CJ CO a — - O CD - . . . CO o . 33 CO Pk « CO W i rH r> U Cd cd ^ ?2 CO CO ^ d o M +i o o M 3 « t^^ CO CO a CD +^ ti) § 13 O ec; O rH CO CVJ CO =*:=«= CD "■"* I — 1 fi fi cow r-H t—i ^--' ^H C) Cl) o 13 K ^ CD P4 o o o w CO n W ^ -p x: ■rl n cd w «j; cd 4J c o 1 — —1 -rl fH cd r-] W S C CD o HJ +^ C) 10 -Jj o W <^ CD fn u a5 ;3 f CO CO p CO > R o CO u rH n („ •H -rl fcH (1) o cd W CO CO ■=^1 -S M to p K-l H M O &-1 ^-« fn O tlO o > a O fn c: CD (D -rH !h CO C3 M « 13 ■'-' b "^ -P CO o 05 fH O ■n ^1 5 W 3 c! W S O -— ,— . +3 rH CO O — O -107- In the San Diego River Basin, as shov-Ti in Chapter VI, it has been found tha.t 332,200 acre-feet of surface storage v/ould g;ive the Aiaximum safe yield possible from the basin, which araount is 698 per cent of the average full natural run-off of the basin above the lowest surface reservoir site for the 46-year ooriod 1887-1933. The capacity of the existing Kenshaw Re- servoir is 696 per cent of the average full natursl run-off, 1887-1933, of that part of the San Luis Rey River Be.sin tributary to it. Analyses of Cottonwood Creek and San Dieguito P.iver indicate that approxinately this sane relative amount of storage will completely regulate those streams. Therefore, 700 per cent of the average seasonal full natural run-off has been assumed as an approximate value of the storage capacity necessary to regulcte fully the stream flow of San Diego County rivers. Vthile this value will vary somewhat depending on the characteristics of the run-off of individual streams and vnth the efficiency of the particular surface reservoirs chosen, it is believed that it is a sufficiently close approximation to shovj the relation between the ultimate storage capacity required and the existing storage development on the streams in San Diego County, These values are shovm in the sixth and seventh colurms of Table 20, while in the eighth col-omn the amount of additional stor- age required for complete conservation of the local vjater resoui'ces is given. In the detailed studies of the San Diogo River Basin it was found that witn the adopted storage capacity a safe yield of 32,500 acre-feet co\ild be obtained from the basin. This is 68 per cent of the average full natural run-off of the basin at Mission Gorge, the lowest reservoir site. This is a somev:hat larger percentage then n?ay be expected on the other streams due to the marked efficiency of the San Vicente reservoir site in saving evap- oration losses. Analyses of several of the potential sites on the streams indicate that an average value of 60 per cent of the aean seasonal run-off may be possible of conservation with a storage capacity of 700 per cent or -108- seven times the near, seasonal run-off. In the minor stream basins v^'hich drain only the lower slopes, less productive of run-off, and \.'ith more erratic stream flow characteristics, it is probable that even with coordinate operation with reservoirs on the principal streams a snaller ainount of the run-off can be conserved and a value of 50 per cent of the net^n seasonal run-off has been used. The farthest dovv-nstream potential reservoir sites are located some distance inland from the Pacific Ocean. The run-off of those parts of the basins reaching the streams bolov/ these sites nay be conserved through the use of underground storage, except such run-off as iriay drain either directly into the ocean or -'nto the r.alt marshes at the mouths of the streams. Accordingly the estimated mean annual run-off as shovm in Chapter II, has been divided into that originating above and bclo^v the lowest potential reservoir sites. Table 21 has been compiled under these assumptions, the second column shovring the area in square miles of the drainage basin above the lowest potential surface storage site, and the third column shcv;ing the mean seasonal run-off in acre-feet of the basin at that point. The fourth column shov/s the estimated total storage capacity required to regulate the run-off to secure the maximum safe yield and the fifth column the maximum safe yield that may be expected to be conserved. In the sixth, seventh and eighth columns the area of drainage basins in square miles below the farthest downstream potential surface storage site, the mean seasonal run-off in acre- feet for these areas and the safe yield from these run-offs that may be expected to be conserved through the use of underground basins naturally available are shown. For the principal streams the estimate of safe yield for the areas below the farthest downstream storage sites has been taken as twenty per cent of the mean seasonal r-on-off and for the minor basins ten -109- (D si 03 U • K 03 •• '■ •• •• " " .. " -d C3 to f-( (i> Xi ^ OJ P>- J- (TN 1^ +J r-^ -H I XX} to en OJ iTs 60 ro ITN Q CJ l—{ LO a cd >» 0) -P ;h ^ * Ci +» 4J C U ID t~, nS ^ f^ r^ r^ ro LO vx) ITN ro iH rH E a «H O CJ -H U . rH >. C O Id C7> CTN OA 0^ 60 6ti Oj #• • • § ■■ ■ • iH W 03 0) •H p, CO >^ u ^ a; 0) (D Ph "0 0^ "0 "0 1 I c rH LO 03 ^ •H (D cd J- r^ OJ 60 1 1 rH r^ Lr> OA cr> OJ Cd p< tM CO >-- C tH a) J- vo r^ 1 — r— ^ ro J- r- q^-- O W 0) •H 1 >:, cd r— cC -tJ ^ tiO -!-> ^ " ^ .. ^ .. *3 !^ ci rH " • 4J o fj 'M I-- 1 I ro OJ 03 tH a .0 c2 3 ■-< «j CO I i3 0) 1— 1 f^ VD OA LTN rH rH ro c« .« • CO (D c8 C S 0) p •H fM * M M M OJ 'H 1 U (0 C\) KA iH r^ ro vrv LO U3 CPi ^ ch >j q bD a CI U nJ j=i 3 oj ^" ^ " ^ " ^ q to 3 -H rH CD ^1 «W tlO-H i q q tH en a c a 0) p n3 -H -H P -H r^ f^ ^ o> I 1 :? r-- CT. 60 ro rH rH tH (D n3 CO cr'-H r^ ^ OJ in 1 1 CTv 6r LO Cd td CO >2'+H Im fH ni CI e rH rH c q td td 03 fp •ai T) ,0 '1 >-^ " ^ " ^ " ^ ■■ ^ " ^ ..^ "^ * * ^ ' • • < • • ^ ■■ ri 6 " -d Lr\ Lf> LTi r^ LO VD LO r-- r— r^ 1 03 a r-i 4J v.^ >■ " ^^^ ^_^ ^_^ %_• N N ^ s^^ to fn Cd 0) ^1 000 "0 Ph 03 ■rH 0) a r^ CJ VD iH LO ^ LO ^^S K'.-, c: '*H *« •» 03 VX) Ch -rt- r^ KA CU ro J- VD J- OJ ^Xl ti--^ fH !-. in iH r^ OJ ro iH OJ LO r5 u rH CfH +» w nj p< . q Ch 03 +3 Cw U (D ^ " ^ " ^ " ^ ^ *' •^ " ^ " ^ '«*->- ^ y OJ C\J (\J ro OJ ^ OJ OJ t\J OJ OJ c: ci " +J <»^ •^-^ "^-^ * — ' •s -- v_^ N • N..^ > — N ' 8 03 f ^1 u (U ti QJ 000 q 03 W 0) (D 000 rH P P. -IJ tti Vi tM J- LO J;_ OJ 60 (H rH J^ iH LO VX3 - fH ^r C/] ^1 -H 1 * •* •" ^ •* VX) S P c OJ fl.r-t CM +i a* -rH fH UD 60 r— ro OJ LO 60 60 U3 ro 60 Cd C/5 OJ rH ro OJ ro cH OJ rJ c ^-> ^ ni CTi r^ to ^— - cd 4^ .. ^ •■ (-1 " — a >j cd C I IC ^ ^ VD J- ITN iH C -H FQ m I S cd g •H :. B rO M U cd OJ LOi ro ^ r-i ^ ^ rj C Cm fH 000 „ " A^ (P -H r-i q Vi t»0 _ 0) ^~^ CO +J nH ;h w 60 ro vx> ^^ OA t— Jt MD OJ 03 a S S c Ol iH J- OJ r~ rH -P 03 CtJ -H .H i^ r— LO> ro ro rH ^ iH iH Cd q (D ttj to o'-w HJ -H fn ^< Cd to B to ^4 <3l -C) ^ 03 -d nd P, 03 03 r-d ■■ ** .. " ■■ u -p ri •H VX) rH •p c ta-^ q u S s £. 10 HH 0) S Cu ^ ■1.9 a--' > p^ ^ •H . — ^ •H u u u u 60 rt (U 03 Ph ^ S3 HJ HJ 03 cd .^^ > (U > ^4 03 03 4«{ > >i-p 03 03 flj •H Tb -rH tl C 03 HJ +> M C >4 ^ 03 •H 03 w +> nj « .H « ^ 0) fc > £? 03 03 ^ 03 w rH S C -rl h CO cd > •H & > 03 03 03 u iH t, Ch ■H h W CO Ti >v, q s -H EH 03 cd +i « « -ij fH •H M K 'd ^^ ^ u Cd >•= S q M CO +J •H Cd W -H rt 03 .H rH tJ Ph 03 u ^ ■H ta 03 •H 3 rH ^( to I ca pq M CO j:J 03 rH CO W Q MO 03 & 03 cd t< C u td -d a 03 > Cd >-^ q ,^ -H 03 HJ •H HJ •H +a w 3-. m ■H S ■H 0) 03 Cd •H td to -P rH •d 03 Cd u « Cm C C' cfl a> P 0) tH 03 -H 0) & W 03 pi 03 cd Cd Hlj > (=< > Pi > HJ > > •-3 > m S CO (=1 N ^ +J rH I ■H +J 000 03 rt^ •H cd -P 1 CO cd Id •H cd Cd -a! W EH & 3 « •H C/D CO to w to EH C to f^ CO CO ^4 •H '!hS" 03 3 v_^ CO- h • • •• Fh ,. .. "H • • ■110- per cent of the moan seasonal run-off not draining directly into salt marshes or the ocean. In the tenth colijmn, the estimated total safe yields for the various stream basins are shc-7n and the total for the entire county amounts to approx- imately 160,000 acre-feet. No consideration has been taken of the economic feasibility or the cost of the physical works required to accomplish this degree of conservation. The total of 160,000 acre-feet is an approximate value V7hich 7ri.ll bo modified somewhat by detailed investigations of the sepa- rate stream basins. However, it is considered to be of sufficient accuracy to compare Vv'ith th3 future Trater requirements and to shov; that the water supplies naturally tributary to San Diego County are deficient in amount to meet the future water requirements. Agricu ltural Laada Oe£l£gy.- practically the entire agricultural development of San Diego County lies on the pacific slope. Geologically this area is divisible into two parts, the highland area made up of crystalline rocks, and the coastal plain made up of sedimentary rocks. The geology of this region has been described in Water-Supply Paper 445* as follows, "The area discussed in this report is divisible geologically into two provinces, one, comprising a region of crystalline rocks that extends from, the eastern boundary of the area westward to the coustal section, practically coextensive with the highland area, and the other a region of sedimentary rocks that lies be- tween the region of crystalline rocks and the oceon and is practi- cally coextensive v/ith the San Diego coastal belt. The boundary between these two provinces is a sinuous line roughly parallel to the coast at an average distance of about 15 miles inland. Through- out most of its length, and especially in the soutnern pert of the area, where the edge cf the crystalline rocks is na.-ked by a rt-nge of mountains, the boundary'' is sharply defined by the abu'inent of •r-he fl-t-Tving sedi'^^'^ts against steep -.vails of '--Pni^rv ^ rocks; *?/ater-Suppiy Paper 4'46, "Geology and Ground Waters of the Western part of San Diego County, California", United States Geological Survey, 1919.- -Ill- but in most places, particularly in the northern part of the area, the sedimentary rocks overlap on the crystallines in such a way that the establishment of a boundary line between the two is more or less arbitrary. There are a fev; outlying masses of crystalline rocks in the sedimentary area and scattered deposits of unaltered sediments occur in the crystalline area. Slates, quartzites, and schists of sedimentary origin are present in the crystalline area, but are so intimately associated with the granites and falsi tes that they are regarded as elements of the crystalline complex." ^o^ls. Detailed soil surveys were made in 19S9 and 1950 of the western part of San Diego County by the United States Department of Agriculture and the University of California Agricultural Experiment Station, .vhich supplant a reconnoissance survey made by the seme agencies in 1915. The detailed surveys are very complete and are mapped on a scale of one mile to the inch, showing occurrences of soils in areas as small as ton acres. A description of the classification and an evaluation of the soils has been stimmarized in Bulletin 552,* University of California Agricultural Experiment Station as follows; "Grouping and Description s. Climatic factors such as precipitation, temperature, humidity, etc., have a marked effect on the soils of any region. The western part of San Diego County receives from 8 to 20 inches of rain, most of which falls during the winter months. The lowest amount is received along the coast and increas'js eastward. 7?inters are warm with little frost on the coastal plain, while the summer heat is considerably tempered by cool breezes from the ocean and occasional high fogs which intercept the sun's energy and reduce the heat and evaporation. Under these conditions vegetation grows freely during winter when the soils are covered with grass and herbage, but by midsummer these have dried up and the soil is dry and often bare. Under these climatic influences the rainfall does not penetrate deeply into the soil, most of it being used by the growing vegetation during the rainy season. The soils usually are leached only through the surface horizons, are low in organic matter, and prevailingly grayish brown, al- though there is a rather wide range in color. "Differences in parent material, degree of weathering, method of formation, and lime content have all contributed their share to *Bulletin 552, "The Classification and Evaluation of the Soils of Western San Diego County," University of California Agricultural Experiment Station, 1933. -112- the diversity of soils encountered. The soils of the highland area generally occur on rolling to mountainous topography where the composition of the parent natsrial has considerable influence on the character of the rosulting soils. These soils usually oxhitit a youthful or only slightly weathered profile. Coarse crystalline rocks such as granite give sandy loam soil, while the denser rocks produce finer-textured heavier soils. Bedrock is usualljr encountered at a shallow depth under such conditions. "The soils of the stream valleys consist of outwash fron the upland region; they exhibit young or immature profiles and have a wide range in color and in lime and alkali content. "The coastal plain soils have light to medium-textured sur- face horizons and heavy clay subsoils. Of these the Olivenhain, Tierra, and Las Flores series have a typical solonetz subsoil (horizon B) , with the columnar structure and alkaline reaction in this horizon, while the Redding series have heavy-textured subsoils of distinctly acid reaction without the solonetz structure. "In any system of soil classification a broader or more com- prehensive idea can be had of the soils of a district if they can be grouped together on the basis of ccramon characteristics, especially when these are correlated rath common agricultural values. In the San Diego Reconnoissance S'orvey the soils are placed in three broad groups defined as (1) residual soils de- rived through the disintegration or weathering in place of con- solidated rocks, (2) soils derived through the weathering and modification of old unconsolidated waterlaid deposits, and (3) recent alluvial soils.* In the detailed surveys of the Capistrano, Oceanside, and El Cajon areas, this scheme has been further elabo- rated to include four main groups of soils, namelj'-: group I, primary or residual soils derived through the weathering in place of consolidated rocks with the development of soils having young or immature profiles and which usually have the bedrock or parent material occurring less than 6 feet from the surface; group II, unweathered secondary soils from alluvial material occurring in river valleys and on alluvial fans, without definite horizon de- velopment and more than 6 feet in depth; group III, slightly to moderately weathered secondary soils from alluvial or coastal plain materials having permeable subsoils and substratum to depths of 6 or more feet; group IV, weathered secondary soils from old alluvial or coastal plain materials having dense or relatively impermeable heavy claj^ subsoils or hardpan hori::ons formed as the natural result of soil weathering processes." *-j. Holmes, L. C. and R. L. Pendleton. Reconnoissance soil survey of the San Diego Region. Field Operations of the Bureau of Soils, 1915, 77p. -113- Soi^l_C_lassifi_c^tj^oji. An evaluation of the soil types has been made in Bulletin 552, from which the follo':7in3 description is quoted: " Sval u ation of the Soils .* * *, all the soil types of the El Cajon, Oceanside, and Capistrano areas have been arranged in a comparative rating on the basis of the degree to which they present conditions considered favorable for the growth of plants. Soils presenting the most favorable general conditions are given a rating of 100 per cent, and the other soils are rated in com- parison. This soil rating, or index of soil value,* is based on the soil factor alone and does not include the effect of local climate, availability of water for irrigation, the locations, or other site factors that enter into land appraisals. In arriving at the 'index' or rating on the individual soil type, inherent soil characteristics are considered, such as the depth, texture, and density of the surface soil and subsoil, reactions, alkali content, and drainage conditions. The rating covers tho entire area of each soil type as occurring in these surveys, and in applying it to an individual body of the soil on a farm, the in- dex rating may have to be raised or lowered slightly because of local abnormal conditions. "On the basis of this rating, the soils have been placed in six grades * * *^ there being a range of about 20 index points within each grade except the last. This gives a considerable range in the index rating of the soils within each grade. Figures 1?, 18, and 19 show the distribution of these grades in the areas. The soils of grade 1 are scattered irregularly throughout the region in small valleys. There is a narrow belt of soils of grade 2 along the coast bordering the broad band of grades 4 and 5 soils which occupy the mesa-liko areas of old marine terraces along the coastal plain. Irregular-shaped bodies of the soils of grades 2 and 3 occupy the upland area between the mesas and the mountains, interspersed with large areas of grade 6 material. The last is nonagricultural because of its stony character and moiintainous topography." These groupings of soil grading T/ere mapped and shown in Figures 17, 18, and 19 of Bulletin 552. The three areas in San Diego County shown on these plates have been combined into one map on Plate IX, "Classification of Soils in Western San Diego County". The acreage of the various grades of soils are summarized in Table 22. These areas are gross acreages and include all waste land such as *Storie, R. Earl. An index for rating the agricultural value of soils. Bulletin 556. University of California Agricultural Experiment Station. -114- PLATE ES PLATE TX :apistrano area R CLASSIFICATION OF SOILS IN WESTERN SAN DIEGO COUNTY FROM BULLETIN 552, UNIVERSITY OF CALIFORNIA AGRICULTURE EXPERIMENT STATION Scale of miles 5 10 1 I Soil grades shown by numbers I J ^ w ^ roads, farmsteads, stream channels and natural drains, etc. Based on the oxporionce in other irrigated areas, it is estimated that not over 90 per ■ cent of the gross area of grade 1 soils 77ill require water, 85 per cent for grade 2, and 30 per cent for grade 3. TABLE 22 CLASSIFICATION OF lANDS OF WESTERN SAN DIEGO COUNTY" : Soil aroa • Gross area, in acres : Soil grade Total : all : grades : 1 2 3 4 5 : 6 :Capistrano :Oceanside :E1 Cajon 11,960 26,624 18,895 17,718 70,813 9,320 21,734 56,931 59 , 838 31,721 59,038, 117,761 16,218 42,944 97,920 77,640 112,960 120,896 176,991: 369,360: 405,130: :Totals 57,479 98,351 118,553 208,520 157 , 082 311,496 951,481: Note:- Areas of grades 1, 2 and 3 lands and "Total all grades" are from Bulletin No. 46, Division of Water Resources. Areas of grades 4, 5 and 6 are compiled from United States Department of Agri- culture, Bureau of Chc-xTiistry and Soils, Bulletins No. 11 and No. 19, S:!ri3s 1929, and No. 15, Series 1930, using comparative ratings shown in Bulletin 552, University of California, College of Agriculture. The area covered by the recent detailed soil surveys includes practically all of the agricultural lands except those located in some of the highlands or mountain valleys. However, these valleys were in- cluded in the reconnoissance soil survey of 1915, which gives an excellent guide to the general soil conditions. These lands are at higher elevations and for the most part have more abundant rainfall with correspondingly -115- roads, farmsteads, strecm channels and natural drains, etc. Based on the oxporionce in other irrigated areas, it is estimated that not over 90 per cent of the gross area of grade 1 soils will require water, 85 per cent for grade 2, and 30 per cent for grc:de 3. TABLE 22 CLASSIFICATION OF LANDS OF \VESTFRN SAN DIEGO COUNT? : Soil aroa Gross area, in acres : Soil grade Total : all : grades ; J. 2 3 4 5 6 :Capistrano :Oceanside ;E1 Cajon 11,950 26,624 18,895 17,718 70,813 9,820 21,734 56,981 39,838 31,721- 59,038, 117,761 15,218 42,944 97 , 920 77,640 112,960 120,896 176,991: 369,360: : 405,130: :Totals 57,479 98,351 118,553 208,520 157,082 311,498 951,481: Note:- Areas of grades 1, 2 and 3 lands and "Total all grades" are from Bulletin No. 46, Division of Water Resources. Areas of grades 4, 5 and 6 are compiled from United States Department of Agri- culture, Bureau of Chojiistry and Soils, Bulletins No. 11 and No. 19, Series 1929, and No. 15, Series 1930, using comparative ratings shown in Bulletin 552, University of California, College of Agriculture. The area covered by the recent detailed soil surveys includes practically all of the agricultural lands except those located in some of the highlands or mountain valleys. However, these valleys were in- cluded in the reconnoissance soil survey of 1915, which gives an excellent guide to the general soil conditions. These lands are at higher elevations and for the most part have more abundant rainfall with correspondingly •115- less need for irrigation. Ccrt^iin crops are successfully grown without irri- gation, although, the climato of these higher olovations does not pjrmit growing as wide a variety of crops as on the cor.stal plain. The areas of good soils lie in comparatively small tracts and will probably not warrpnt any extensive irrigation development. Only a very small aroa of these lands has been developed at the present time. It has been estimated that a net area of 10,000 acroa of irrigable lands lie in those mountain valleys. While sane grade 4 lands in the county have been developed suc- cessfully, it is considered that their character does not justify any ex- tensive development for water for irrigation purposes. Municipal develop- ment will cover some of both grade 4 and grade 5 soils, but the total amount of water used primarily for irrigation on these soils will not be large. In view of the relatively large area of better soils in comparison vrith the available water resources, no allo77ance has been made for the use of water on grades 4 and 5 soils for irrigation. The areas of net irrigable lands are shovrn in Table 23 together with the ultimate v/ater requirements for irrigation use. Fu_ture_Deve^lop^nt of I_rrigable Land_s - Many factors favorable to the in- creased use through irrigation of the large undeveloped area of excellent soils remaining in Sau Diego County exist. The area of practically frost land offers the opportunity for increased production of many semi-tropical fruits. The increasing urban population affords a growing local market for all types of agriculttoral products. The long growing season, year round in many localities, makes it possible to produce many veirieties of vegetables that may be marketed during the winter and early spring when crops are either dormant or just being planted in many other parts of the coimtry. There is a large area of good soils uithin the water service areas of existing organized agencies which may be developed, -116- [i«r*t. TABLE 23 NET AREA AND ULTII.IATE SE^^SONAL WATER REQ,UIREM2NTS FOR IRRIG;^LS LAiroS IN S3I DIEGO COUNTY |Soil area Net irri{.:able area, in acres Average : Seasonal : water : requirements, : in acre-feet : Soil grade ' Total : gross allowance, : in acre-feet : per acre : 1 2 3 : jCapistrano 10,764 15,060 17,387 ; 43,211 : 1.30 : 56,174 : :Oceanside 27,962 60,191 45,535 : 129,738 1.30 168,659 : :E1 Cajon 17,006 8,347 31,370 : 57,223 1.30 74,390 : : Highland : valleys 10,000* 1.30 13,000 : : Totals 51,732 85,598 : 94,842 240,172 - — 312,223 : *Estimated from "Reconnoissance Soil Survey of the San Diego Region, California, "United States Department of jYgriculture, 1915. Other factors which may retard development are also present. The scarcity of additional water supplies that may be cheaply developed, will tend to prevent a rapid increase in irrigated lands. The City of San Diego has acquired water supplies from Cottonwood Creek, Otay River, San Diego River, and San Dieguito River for municipal use and the future development of these sources may be, for the most part, for this purpose rather than for irrigation. The irrigation development has progressed at a rather uniform rate since 1888 when the first large water supply works were constructed. The growth has been shown in Chapter III, Table 14 and is shown graphically on the upper diagram of Plate X,, "Water Reriuiremonts of San Diego County with Assumed Pates of Future Growth." While little if any increase in area occurred during the decade betreen 1910 and 1920, the formation of several irrigation districts in the decade between 1920 and 1930 and the resulting development -117- brought the growth up to the ••iVvir''6c, rito for the tv;enty yo'-.rs, 1B90 to 1910. .'StoT considorntion of the various factors involved, the nverngo rate of growth from 1890 to 1930 hcis bean projocted forr/Td from 1930 to 1980, and the values obtained aro buliovcd to bo rocasonablc estimates for the purpose of sotting forth future irrigation w'ator requirements. The average rato of growth from 1890 to 1930 has been approximately 9,000 a.crcs per decade. Projecting this rata of growth into the future gives an area of 54,000 acres for 1940; 63,000 acres for 1950; 72,000 acres for 1960; 91,000 acres for 1970; and 90,000 acres for 1980. Population of Urban Areas, Urban population as defined by the United States Bureau of Census, is in general that residing in cities or other incorporated places having 2,500 inhabitants or more. For use in connection with the 1930 census, the definition of urban territory has been slightly modified and extended, but this change does not affect San Diego County. Under this definition, seven of the eight incorporated cities in San Diego County are classified as urban areas. The cities of Oceanside and Escondido and the towns along the coast are situated where their future growth will probably occur on lands classified as irrigable. At present the average use of water within the developed portion of the City of San Diego is about 1.06 acre-feet per acre, and for the City of Coronado, about 0.98 acre-feet per acre, while in the city of Oceanside with more irrigated land vdthin the developed area the use is some- what larger. With fut-ure growth the density of the population and use of water will increase due to the building up of the vacant areas, and the irri- gation average net allowance of 1.25 acre feet per acre will probably be reached. For this reason, the future water requirements of Oceanside, ■118- Escondido and other residential areas in the northern part of the county, whose future growth Trill bo for the most part on irrigable lands, may be considered as included in the future irrigation 7?ater requirements of the county. In the metropolitan area of San Diego and environs almost the en- tire urban development has been made on soils TThich have been classified as grades 4 and 5. The groT7th in population in this metropolitan area has been much greater than that of other parts of the county, as is shov7n in the last line of Table 24 which tabulates the grovrth of population of incorporated cities in the metropolitan area, and gives the percents-ge of the inhabitants of the county living in these cities. The City of El Cajon has been included in this table as its water supply is secured from the same source as the City of La Mesa, although it is not classed as urban by the census definition. ?u_tiare_3ro77t^ _of_Popul_ati_on- The region surrounding the metropolitan area consists for the most part of grades 4 and 5 soils, rrhich while of low rating for agricultural purposes, because of their location, topography, climate and other advantageous factors are of high value for residential and other urban purposes. Due to the concentration of population in the metropolitan area and the types of soil therein, the estimate of future water requirements for this area has been made on the basis of future growth in population rather than on area of land. It should be understood that the estimates of future growth of population and of irrigated lands have been made for the purpose of showing that the ultimate development of San Diego County is definitely limited unless the local water supply of the county is augmented by importation of water from other sources. The rates of future growth of population and of irrigation development are dependent upon many factors, some of which are known and their effect estimated with reasonable precision, while many others -119- T/3LE 24 GROTTH IN P0PIIL.1TI0N OF INCORPOR,'iTZD CITIES IN METROPOLIT.uN .iR5L'^ : City 1350 1370 1880 1S90 1900 1910 1920 : 1930 : : San Diego 731- 2,300 2,637 16,159 , 17,700 39,578 74,361: 147,995: : National City 248 1,353 1,085- 1,733 3,116: 7,301: : Coronado I 935 1,477 3,289: 5,425: : Chula Vista 1,718 3,869: : La i-[esa ! 1,004: 2,513: : El Cajon 469 1,050: : East San Diego 4,148 : Totals 751 2,300 2,885 17,512 : 19,721 42,788 88,105 158,153: : San Diego : County 4,324 4,951 : 8,618 : 54,987 : 35,090 : 61,665 ; 112,243 • 209,659: : Per cent : of eounty : population in : metropolitan : area • 16.9 46.5 : 33.5 : 50.1 : 56.2 69.4 78.5 : 80.2: are unknown or difficult to evaluate accurately. Consequently, these estimates are not presented as a prophesy or prediction of what the future grovrth in population may be, but to show that, without consideration of cost or economic feasibility, if the irrigation developnient and utilization of water continues until about 1955 at the same rate of increase as it has since 1390, only suf- ficient local water supplies can be developed for municipal and domestic purposes to support a population of less than 500,000 in the metropolitan area. Increase of irrigation development at a greater rate than that estimated ■ -120- would further limit the population growth, as might the factors of cost and economic feasibility of the complete development of the local water resources. In estimating the future growth of population, the past growth of many larger cities in the United States has been considered. However, due to large movement of population from the rural areas to the cities in recent years and a reversal of this movement during the present period of economic depression, it is thought that a more reasonable basis of estimate may be secured by using an estimate of the future grovrth of population of the State, which has been made in a previous report* and covered the period from 1930 to 1979. In that report a detailed analysis of the factors entering into the population grovrth of the State of California has been made and from xhat study four estimates of future population are given showing limits of future growth. Those estimates have been designated as "Extreme lower limit", "Reasonable lower limit", "Reasonable upper limit", and "Extreme upper limit", giving for 197C - 11,100,000, - 16,900,000 - 20,300,000, and 25,300,000 for the respective estimates. In estimating the future growth in population in the metropolitan area of San Diego, the estimate designated as "Reasonable lower limit", has been adopted as a base, and estimates made for the County of San Diego, and the metropolitan area. These estimates are given in Table 25 and the estimate for the metropolitan area shoT7n graphically on the upper dtagram of Plate X. As may be noted in the third column in Table 25 the percentage of population of the State living in San Diego County has increased since 1900 from 2.4 per cent in that year to 5.7 per cent in 1930. This trend has been disregarded and the 1930 ratio of 3,7 per cent used in estimating the future growth. The percentage of inhabitants of the county living in the *3ulletin No. 35, "Permissible Zconomic Rate of Irrigation Development in California", Division of Water Resources, 1930. -121- ,i:_,N •• •• w .. . • •• • . .. . • •• • • •• • . .. . ■• • .. . •• h "H d CO r^ O u - •rH O CO •^ >* CJ o 'J* ^ to 0) to rH r-H -a a • • • • • • • • • • O 0) • +J -p ^ 73 »H o C7 o O O O o o o O o o o u u o Q) o o O o o o o o o o o H (D P< ^1 2- +i . rH :5 1 •« • •k •k #• CJ* cd fn CO M 0) -*" -^ in CO cn ■># oo" iH CVJ O g ^ ° +^ fH H cu to ■* IN o CVJ in C-- (T> o EH to .-4 rH H H H ,H to U a 'O a; o d p O cO '•» 0) -P cd H H rH O I O o o o o o o o o O 5 .^ ^ to W d (D 1 o o o o o o O o o O Q) 13 P CO CO 'J* w CVJ cn ID CO o (D JH CD B d o g a 1 I *t .^ •» • 9* « •k M * ■P -P +3 q ;h o -H Q) H 03 cn (.0 CN o H to li) c~- CO CO o rH ca C\} to in (N CO cn o H S '> o S m f-( <;h CO 1 O o o o o o O o o o += M ^ (D 3 O tJ 1 O o o o CD o O o o o ,03 rd -P CD C! 1 •k M • » •« •* •* * ■P IH -P CO CO g E-. ro -a 3 CO -p -H 01 tN CO o" ^e* >:}< CO CVJ rH o <; C 'Vh CD CO rH CVJ CJ '^ in to CN CO Oi •d to p o [^ CO fH tuj - -p u M o tJ CO ■'H CO -P O fn "O S CO K -P +^ f-' C f^ -t5 ?^ n Eh CO CO ffi -H CO ■rH CO ^1 S g S '^. H f. .. t! .. • & S ;3 O 'H +3 1 . .. . i: -P :ni in p ^ W Eh K .:. g . . r— ) o o o o o o o o O o (0 to ^iH O 1 +:i CO -P o o o o o o o o o O o ^ (D ■H O CD - CO 00 UD cn CVJ CO CV! 0-- o Q) .d C ^H e Fh p ::i -rH CO >tH e 3 Vh 1 *t . .\ »k •t •» •• .* * Xi -P § g^ CM w in H rH C3 C\2 to to ID >* CN in tN ^D CO CN !D -P CO "H Eh cr o d Q) O " O « fH 0) CO fn P CD d e-t M C5 Sh CO 4^ O m Eh d +J -H CO :n o tN c<;i ^ l:) in fn O to Kl r-l p. . CO <£> CO o .. .. . . . . .. .. . 'd o 03 c- o m CO cn o o o o o H Ti PH & >5 tH co o tD ^ l:i o o o o o •£ "^ -t^ L^ O -P iD en O ID CJ tD •rH ^1 3 ^ P, p to " iH . 1:3 +J 1:1 >j ^1 O (D d o 0) +' OJ -P o o -^ to eg IN o IN t^ IN IN ■H H d -p d p, -P CO • • • • » • • • • • • CO =3 d +^ H CV! c\: CO tf> CO CD CO CO CO to ti P( w g O d (D CO -H •H •rH +^ (0 O •rJ o -P o d -H -P . d M O CO T^ 00 « cr> rH rH O o o o o to o in vl" ID in o o o o o g ^ . Ti o d vD CO CJ in- CO C\2 o o o o o d M •t M .> •k •« •» • Pr'd >. CO o o ^ to" in tN ID !N o o o o o d 4^ -P Vh U) H CO C- CI ts OJ CO CVJ o o CO CO d +3 C3 •H CO CM o o o o O o O O CO CO CT> O rH CVJ to 'i' in ID IN CO ■ • (D CO CD C7» Oi cn cn cn cn cn cn cn >^ H H H iH >H rH • • •• H H r-l H H ■p -122- metropolitan area, as shown in Table 24, has increased from 15.9 per cent in 1860 to 80.2 per cent in 1030. This trend also has been disregarded and the future population of the metropolitan area assumed to be 80 per cent of the county. These factors of 3.7 per cent of the State and 80 per cent of the coiinty have been applied directly to the "Reasonable lovrer limit" estimate of Bulletin No. 35 in the fifth column of Table 25 and give an estimated me- tropolitan population of 252,000 in 1940, 344,000 in 1950 - 430,000 in 1960 - 500,000 in 1970 and 550,000 in 1980. The estimate for the State for the year 1980 has been secured by an. extension of 1940 to 1970 estimates of Bulletin No. 35. Estimated Future Water Roquiromsnts. The estimates of growth of future irrigation development and of population in the metropolitan area have been made as a basis for determining future water requirements. A comparison is made between the future water re- quirements and the local water supplies which are possible of development in order to show that there is a large deficiency in local supplies and that if San Diego County is to continue to develop its resources and to increase its population, it must secure and import "vater from other sources. As has been shown in Table 23 the ultimate water requirements for all irrigable lands in S&n Diego County amoimt to about 310,000 acre-feet. The favorable living conditions and many other favorable factors afford the opportunity for continued growth in urban population with resultant large water requirements. T?ith a maximxxm safe yield of approximately 160,000 acre- feet possible of development from the local drainage basins, the ultimate de- ficiency of local water supplies amounts to 150,000 acre-feet without con- sideration of the municipal requirements of the metropolitan area. Looking into the immediate future, however, the water requirements •123- have been computed on the basis of the estimated growth in irrigation develop- ment using an average gross allowance of 1.30 acre-feet per acre and of the estimated growth in population of the metropolitan area using 120 gallons per capita per day for municipal purposes in this area. With these unit valuss, and with the estimated future areas of irri- gated lands and estimated future population of the metropolitan area the future TTater requirements have been determined and are shoT7n in columns six and eight of Table 25 and the combined totals shown in acre-foot in column ton and in millions of gallons per day in column eleven for each ten years from 1940 to 1980, The values in acr j-f oet are also shoTOi graphically on Plate X. As the maximum annual safe yield from the Pacific slope basins of San Diego County has been estimated to be 160,000 acre-feet, it will be seen that to meet the future water requirements, full development of the local water resources must be accomplished by some time in the decade 1960 to 1970, if the growth of irrigation development and population is to proceed at the estimated rates, or earlier if these rates are exceeded. This may also be presented without consideration of the future rate of growth. In 1933, almost one half of the ultimate development and utilization of the local water re- sources has occurred. The limit of growth possible without importations of water is approximately twice the present development if the 1933 ratio of irrigation and population is maintained, or as approximately the same amoixnt of water is required per acre for either irrigation or domestic use, the com- plete development of the local water reso-orces will furnish a supply sufficient for a total area of about 125,000 acres. As has been shown in Chapter II large seasonal and cyclic varriations occur in the run-off of San Diego County streams. To regulate run-off having such wide fluctuations and secure a dependable water supply therefrom, -124- 1/1 V L. O c O I- -a -op 1_ I. NET IRRIGATED LANDS AND POPULATION 1 I 1 ; 1 Note:- The diagrdms shown on this plate are for the purpost of snowing the limitations of development de- — pendent upon csnservable water supplies naturalljr avail- able to San Diego County and are not presented or to be considered as predictions of future growth of popu- 80 Area of Irrigated Lands ./ X ^ 60 * y y y 40 P* ^^ ^ y" 1 •■ ^ y • ^ 20 .y" i> f ^Population of Metropolitan Area Q ^ ^ ^ \^ n y y^ PLATE X 10 w 8 Y 01 to o 10 ■o ■a c c o '+- ca 3 O 1880 1900 1920 1940 1960 1980 Year 4) 200 M- 0) I. i* 30 -S 50 -Q 60 o ^ 80 100 , \ J J ,/ b \ 1 / i { t / y T ^ny k^ s. f^ rP' t^^ n '^ ^__ .^— •"^ PRO 1 2 3 4 5 6 8 10 ZO 30 40 50 60 80 1 Gross yield in thousands of acre-feet BABLE FREQUENCY OF GROSS YIELD OF SAN D EGO RIVER 00 frequency of occurrence in 100 years determined using- the method described in Chapter V under "Mean Daily Flood Flows." They have been plotted on double logarithmic paper on Plate XI and a smooth curve interpreting the trend drawn through the points. In Chapter VI, Table 34, the estimated annual safe yield of the San Diego River for full development has been shown to be 32,500 acre-feet and the average seasonal evaporation from reservoirs during the period 1894-1933 to be 9,400 acre-feet. Assuming that this average value of evaporation would obtain over the 50-year period 1883-1933, the annual gross yield necessary to produce a annual safe yield of 32,500 acre-feet would be 41,900 acre-feet. Entering the diagram with this value, it is found that this gross yield may be expected to occur 12.3 times in 100 years on the average, or approximately every eight years. Therefore, it would appear that the full safe yield of the complete development may not be seciired until eight years on the average after the storage reservoirs have been completed and put into operation. For partial development the full safe yield may be expected to be secured in a shorter time on the average. As other streams in the county have similar characteristics, similar studies on them would probably show about the same average period. These erratic characteristics of stream flov/ require that the future needs must be anticipated many years ahead, adequate development made and sufficient water carried in storage to '.neet these needs, if a serious water shortage with resultant large economic loss and retardation of the natural grov/th of the county is to be prevented at some future date. ■126- CHAPTER V FLOOD COi^TTROL The major and minor streams of Sej^ Liego County are for the most part deeply entrenched in the terraces of the coastal belt. The valleys vary in width from a few hundred feet to nearly two miles. Their floors are flat trans- versely with fairly steep stream bed gradients, and ere bordered by steep slopes or bluffs several hundred feet high. 'I'ith the exception of the delta of the San Diego River between Ilission and San Diego bays, the debris cones are small. The existing stream channels are shallov; vjith poorly defined banks and are cap- able of carrying onlj'- the smaller floods. In times of major floods, practically the entire valley floors are under vrater. Although the areas subject to demage by floods comprise but a small portion of the totel area of Ssii Diego County, they do include a large acreage of good agricultural soils, which are well adapted to raising of field crops, vegetables and dairying. The areas subject to flooding are shovm on Plate ZII, "Areas Subject to Flooding in Sail Diego County." The flood of 1915 caused a preat amount of damage in the river valleys and to lines of communication in and crossing these valleys. It has been estimat- ed'^ that the totcil damage from this flood in San Diego County amounted to more than .Ip4,000,000, of which l';l,500,000 v/as estimated as the value of the agricultur- al lands destroyed. From the experience of this flood, many lines of communica- tion have been revised as to location and greater channel cppacity has been con- structed under bridges. Until recently few residences have been reconstructed in *United States Geological Survey, Iv at er- Supply Paper 426- "Southern California Floods of January, 1916," by H. D. I.IcGlashan snC. F. C. Sbert. ■127- PLATE Xn valley floors in areas below the flood plane and very few permanent crops have been planted. At the present time, however, residences are again encroaching on the flood plane in the Tia Juana and San Diego River valleys and in some of the other valleys permanent crops are being planted. In the urban areas, many of the minor stream channels have been encroached on and are liable to inundation in a major flood. History of Floods in San Diego County . Although the history of San Diego County begins with the founding of the Mission San Diego de Alcala in I769 > no records of stream flow were kept and but little is iaiown of the flows in the streams prior to the period of water development which began about 18S7 when the Sweetwater and Cuyamaca reservoirs were built. The only data available prior to this time consist of the old Mission records of crop production and notes of stream flow and channel con- ditions in the diaries of the Mission Fathers and other early travelers and in later years the testimony of early settlers. These have been analysed by H. B. Lynch in a report to the Metropolitaji Water District of Southern California entitled, "Rainfall and Stream Run-off in South- ern California since I769." He states that a study of these early re- cords indicates t hat floods occurred in the following years: 1770, 1771. 1772, 1776, 1780, ISll, I8I5, I8I7, 1825, 183^, 18^0, ISU2, 1850, 1852, 1853, 1S60, I862, I867, 1868, 187^, I876 and 188U. Of these floods, that of 1825 caused the change in the course of the Santa Ana River from its old outlet in Alamitos Bay to its present outlet near Newport andof the San Diego River from Mission to San Diego Bay. The flood of 1862, however, is said to have been the largest on the San Diego River at San Diego within the memory of any -128- of the inhabitaiits then living. Since 18SS there have been many- minor floods in San Diego County hut only tvxi major floods, those of January I916 and February 1927* Although these two floods were of about the same size in many of the mountain areas, that of January 1916 seems to have been generally larger in the foothill areas and at the mouths of the streams. The Mission dam and the conduit leading to the San Diego Mission were probably built some time in the period 1813-15 and. were probably maintained in efficient condition \xntil about 1833 when the missions were secularized and the mission organization was de- stroyed. In 18^5 the San Diego Mission had been abandoned and many of the mission buildings had already collapsed. The buttress on the left end of the dam indicates that at some time in the period ISI3- 1833 > possibly in 1825. the left abutment of the dasn may have been washed out and replaced by a wall to the nearest exposed rock some- what downstream from the main axis of the dam. Observers about IgJO state that at this time the left abutment had again been destroyed. Photogra5)hs of the dam taken prior to the flood of I916 show that at that time it was heavily overgrown with willows, most of which were torn out by this flood which also destroyed additional portions of the left abutment of the dam and many sections of the conduit which had survived until that time. The flood of 1862 is said to have been higher than that of I916 , in the vicinity of Poster and Lakeside, and to have flooded houses at Old Town, San Diego. On the San Luis Hey River, however, the flood of I916 vvhich destroyed an old mission ditch which had survived the flood of 1862 is said to have been higher than that flood. In comparing these two floods, it should be noted that minor floods are said to have occurred with reasonable -129- regularity prior to 1862 and that, at that tirae the stream, channels were probatly in a fairly clean condition, vrhereas in I916 , v/ith the exception of one moderate flood in I906 , there had been no flood of appreciable size since lS95,and that the stream channels, therefore, were probably heavily overgrovm w ith trees s^id brush as is witnessed by the overgrown condition of the Saji Diego Mission Dam in I916. Prom the available data, it seems probable that in the 165 years since the first settlement was established in I769 there have been at least four major floods, those of 1862, I916 , 1825 and 1927, with a possible fifth having occurred in lySC. It would seem, therefore, th^t major floods of a destructive magnitude may be expected to occur about once in from 30 to Uo years on the average. Characteristics of Flood Occurrence . A discussion of the general types and characteristics of the storms which bring precipitation to San Diego County has been given in Chapter II. In this discussion it was pointed out tixat even in the higher areas only a sinall percentage of the precipitation occurred as snow and that this snowfall liad but little effect on the stream run-off. There are no records extant which indicate that any flows of appreciable magnitude have resulted from the melting of snow without coincident rainfall. Floods in San Diego County are the result of, and occur coincidently with excessive precipitation in the form of rain. Time_of Oc£urr^n£e_of Fl2od Fl£w_s - On Plate XIII , "Time of Occur- rence of Floods on Two Streams In San Diego County," the maximum mean daily flood flows of the U5 largest floods of record in the period 1888-1933 on the Sweetwater River at the Sweetwater Dam and of the 33 largest floods of record in the period 1900-1933 on the San Diego River at Diverting Dam have been plotted against the date -130- 0^' their occurrence to^^ether with the mean and i;iaxiinurn monthly rain- falls at the Sweetwater and Cuyainaca Dams respectively. An insoect- ion 01' uhese tSraphs indicates the extreme seasonal occurrence of rainfall floods in San Die^-o County, No floods hive occurred prior to the first of November or after the :;.iddle of May and no floods of a^^preciahle magnitude have occurred prior to the l^th of Deccuhcr or after the 1st of April » Tl'.e mean mont'aly r ainf 'lis dj-iiiig bhe months from December to March are at least tv/ice the mean for any other month of the year and the m^aximi'v.im monthly rainfalls for the months of Decembeij January and February are at least tv/ice as large as those for any other month excepting I-arch and April. The graphs also illustrate the wide variation in the sizes of the floods w'lich m.ay be e:q)ected to occur. It -"ill be noted that the large majority of the floods o,rc relatively small and unimportant but that twice, in the 45 years of record, floods have occurred which were f-ar larger than any of the others. On the S"/cetW3,te.r Eivcr the smaller of the two m.ajor floods was 1.9 times as lar;je as the largest of the minor floods and on the San Diego Siver 2.5 times as large. The first of these floods occurred in I916 , aboiat thirty years after stream flow records were first kept in San Diego County and ^h .years after t'he last tradition?.l major flood. The second of the recorded m.ajor floods occurred in 1927, only eleven years later. Variat_ion £f_Tnten_si t^i_es_o_f Flood FljOw_s - The Pacific slope drainage basins of the Peninsula Rajige in San Diego County rise from sea, level to elevations of from UCOO to 60OO feet irj an air line distance of frcra ho to So miles. The intensities of storm rainfall vary considerably in the various narts of the drainage basins. Pvecordo of the d.-^ily rain- fall at most of the precipitation stations shown on Plate I and listed -131- PLATES Xm AND XEI < V z t- \ u o d in u. O z o 5 5 \ \ \ \ \ \ > \ \ ■^ S z « i _J UJ § to 2 _ wfe^ _ Z i yW- 2 D- < __^ o o o S| \ z N N < Ul V 2 \ nj V ■o UiPQ SuiiJSAtQ i -\ \ o o . iu»a un.dto n -p- \ o *, 1 > X 1 ) I 1 o jy O LU 34.isii«0 Z ON aS-iof) uo1«:sl^^i ?//i >( ! "A' o l D iL r rt 1 1 1 1 1 1 >- t- z lU I- Z z v; K ^ 2 V\ < UJ \\ 1^ 1- o \ Z D < \ S c .t; < \ ^°° N o °^ u. \ o 5 H z z '\ O u l\ 5 " trt .N. 5 z \V < s u nN 2 V \ ( \ )i ^ s. uiseq jo> uesui jo luao J3d ui Luniep S3Sn 'l^^J '-'! uoiiEA3|a ues^ uiseq joj ueauj ^o iu33 jad ui 1- co Z z UJ uo h- < 5 z cr 111 2 5 cr > UJ C£l u 1- cr 1- i/) O o ii ej o UJ UJ r't (O z < o z m 1- < < CL < > ueQ ja4.eM4.a3AA9 4.5 9aL|0ui ui ne^uiGJ /]m.uo^ eoeiue/n^ +e saqoui ui ne^uiej X'm+uo^ < ui < (X ■5 _j 1 1 1 ! > < U E '^ 1 i 1 i 3 1 1 1 1 z n 1,1 ^ 1 1 1 1 — ' ! 1 1 i\ a: 1 1 1 • i 1 » 1 UJ 5" - i i 1 1 1 '-A 2: i li I' » I 1 1 lo !>;. §' 1 1 ! H 1 ' 1 i ; M ' a. Ui m -1 1 1 1 bl 3 u, I < > 0: < < a 3 1 1 >1 8 5Z? 3 1 1 3 -> UJ UI — a UJ *^ II 1 i Z z > Z 1 T -:i a 3 1 ^ 1 1 1 1 1 1 (t" 1 1 1 0. < 1 h 1 1 1 1 1 1 %» ^ m S.I t «•« u. 1 " ** 1 J" 1 T «« < 1 1 1 I n a 1 I i!^ 1 1 •^ 1 ■^ 1 le H 1 I ' 1 , 1 ! 1 133^-puo03s J.0 spuesnoqi ui vo|j. X"|iep usa^ I93j.-pu03as y) spuesnon+ ui mo|^ ^liep uesiAi >- H CO Z Q 13 O O O U O U u z on D O o o o UJ h- O O u z < < u or. H (/) O I- £ >> — n: ro X S 25 in Table 2 are available for periods of from one to over °!0 years in length. A detailed analysis of the valuations in the storm intensities of precipitation has been inade for the San Diego River Basin, Tliis analysis has been based on the records of daily rainfall at thirteen stations in or close to the S?.n Diego Jiiver drainage basin. Since the records at some of the stations v/ere talcen in the morning and at others in the evening, tv/o- day rjiinfalls were used in the analyses. Tlius , the storm raini-^Jl inten- sities compared represent the rainfall d\iring tiiesaine thirty-six hovir neriod at all stations with the addition of the rainl'all during a perior' of from 6 to 12 hours, either before or after the coincident period at individual stations. Since the period of record at three of the st^.tions used only covered the seasons 191^^1917 > this period of record has been used in the analyses. The analyses, based on the trn largest tv/o-day rainfalls during the period of record, are shown on Plate XI?, "Variation in Storm "Rainfall Intensities in Sn,n Diego Hiver Drainage Basin based on Ten Two-d-^y Periods 191^-1917." Tlie upper i^raph on this plate indicates the variation of storm intensity expressed in percentage of the mean intensity of the drain- age basin, with elevation. These data are a.lso given in tabular form in Table 26. The middle graph shows the profiles of the di'ainage basin from sea level to the divide. The lower -^raph shows the profile of storm in- tensity f rom s ea level to the divide. It will be noted that the increase in the intensity of the storm rainfall is quite uniform from the coast to the divide in the San Diego F.iver drainage basin. Since flood flows in San Diego County are the result of intense storms, it would be logical to expect that the intensities of flood flows v/ould vary with the 'inten- sities of storm rainfall. -132- TA3LE 26 VARIATION OF Il^SHSITY OF STORl.I PAIIIFALL 7ITH SLEVATIOH IH TH3 SANDI3G0 raVEE DPAINAG-E BASIN : Prec" Lpitation stn,tion Elevation, 2-da.y storm rainfall : : l^vLT.b er I/'ean of ; l.Iean intensity, : : on Name in f oet 10 storms : in per cent of : rPlate U.S.C-.S. 191^1917. mean of basin : : I datuii in inches • 6q S-^-n Diegc S7 iM '• U2.I : : 7U Cliollas Heights 370 2.09 60.2 : : 75 t^urray Dam 500 2.U2 £9.7 : 90 Los Coclies 710 2.45 70.6 : : 33 El Cajon #3 56o : 2.60 74.9 : : 31+ El Cajon Valley 670 : 2.6U 76.1 : : 96 Diverting Dam sUo 3.00 S6.5 : : 91 Chocolate 760 : 3.12 ?9.9 : : 52 : Rar-iona (Sentinel) lUUo : 3.23 93.1 : : 97 Boulder Creek 2990 : U.30 123.9 : : ho • Santa Ysabel Store 2983 : U.32 I2U.5 : : 101 Julian : U222 4.96 1U2.9 : : 98 Cuj'-amaca Dam 1+677 : 5.^2 : 156.2 : • Averages for : drainage basin of : I8U3 3.47(1) 100.0 : San Diego Hiver above Old Tovm (1) Weighted by areas betvreen 5OO foot contours. Frequency analyses of mean dail," flood flows have been rnade at three points in the San Diego Ziver drainac;e basin, the Diverting Dam, the Mission Gorge and a.t M-arrr;^ Dam. Kiese are presented in Plate XV, "Probable Frequency of Flood Flows from Drainage Basins in San Diego County." The analysis of flows at the Diverting Dam indicates a probable once- in- 100- years m.epji daily flood of 13,500 second-feet or of I3I second- feet per squaJ"e mile of djaina.ge basin. The analysis of the flows at the Mission Gorge indicates a once-in-100-years mean daily flood of U0,300 second-feet at th-at poi.-.t. Tlie mean dolly flood from the area bctvreen the Diverting Dam and Mission Gorge therefore -Tould be about 26,800 second-feet ■153- 05 Of ! 'T , , ' ■ 1 It! «> 8 T " >^ O c V o c O V o c o t_ o o *+- o g t|- o U 10 lU g- L ■+- 3 -Q J ■ ^ l- o a. 50 - 100 t -1— ' -- Q5 no 0.5 IS >^ o o c _Q -Q o 10 50 100 Mean daily flow in thouaands of second-feel Mean dailj' flow in thousands of s«cond-feet lands of second-fee ' ' ' ' / / / / / / f /\ / ftRCARITA niVE SIDORA / / Mean daily flow \n thousands of second-feet i 10 ' 1 ' r " -■ / ■ / . /' / / /- - / / > • - '? / . -^ SAN LUIS REY RIVER HENSMAW 0AM ARC* :ae saunRi wiles / y t 3 ' ' ' ' / *'c>U'n'i '7 / / / / / SAN LUIS REV RIVER OCEANSIDE — \ — ' ' / ' / - / ■ ■ /I ■ ( / ■ = / / ° - . •v / ■ y SAN DIEGO RIVER DIVERTING 0AM s/ Mea n daily flow in thousands of second-fee 10 ao 00 ' ' / / ' / ' / / / / SAN DIEGO RIVER SAN DIEGO *BE*41S iOU*at MILES •V£«.OE El,ev»TION IB4J ftEl ^ / Mean daily flow in thousands of seccnd-feet Mean daily flow in thousands of seeond-feet Moan daily flow in thousands of seeond-feet Mean daily flow in thousands of second-feet Mean Aa\\y flow in thousands of second-feet lOO OS 1 S 10 so 100 05 1 S 10 50 100 001 OS OJ 05 ' • J "T" — — ^3:;;: - ~ _£z::: / - / . . — — — / — , - ■ - / ' y e, V Ar HODGES 0AM 1 13 „.»«E MILES 1 ^ ^t- — - *''t''">* LEV* lUH 1965 nn 1 ' ' ' ' 1 ■ / ■ / / - V / ^ / ' / ■ 9" - ; SAN OlECO RIVER MISSION GORGE AflE» 376 SOU*SE MltES V ' ' ' / ■ - /• . / t o / ■ '•/ / ■ ■ /^ ■ ;*» SWEETWATER RIVER SWEETWATER DAM «V£fi*OE ELEVM-ON 2391 fEET '-' ' ' "^ / ' / " — --> - 1 ■ / - / / ^ -' - - NESTOR \ — ' ' Mean daily flow in thousands of second - feet ' ' ' ' 05 1 8 1 - c / - i / \ . 1 s ' / : / •° - 2 t./ (t .'' py MURRAY DAM so ^ — • - — . — UN •"'"' 1 ' ' ' ^ t / - \ / - / D \ / % ■ / / y - i / - -'/ COTTONWOOD CREEK BARRETT DAM «BE* ;t9 S0U4HE WILES AV(B*6E (LtVATION 3687 FEtr 50 J x i 'A PROBABLE FREQUENCY OF FLOOD FLOWS FROM DRAINAGE BASINS IN SAN DIEGO COUNTY or 9S second-feet per square mile. Based on these figures, floods from the area above the Diverting Dam would be about 1.3*+ times as intense as those from the area between the Diverting Dam and the Mission Gorge, The average elevation of the area above the Diverting Dam is 3507 feet; of the area between the Diverting Dam and the Mission Gorge, 151^ feet. Applied to the upper graph, Plate XIV, these average elevations in- dicate storm rainfall intensities of about 133«5 and 100,5 per cent of the mean for the totaL basin respectively. Based on rainfall intensities, therefore, floods from the area above the Diverting Dan; would be about 1.33 times as intense as floods from the area between the Diverting Dam and the Mission Gorge. This figure is in substantial agreement with the ratio indicated by the flood flow analyses. Consequently, it would seem that flocd. flows in the San Diego Hiver Basin above the Mission Gorge might be expected to vary directly with theintensity of the storm rainfall. The third record of flood run-off in the San Diego River Basin which has been ajialyzed is that of Alvarado Canyon at Murray Dam, a portion of the San Diego River drainage basin below the Mission Gorge. This analysis indicates a once-in-100-year mean daily flood flow of 505 second-feet or about lUO second-feet per square mile from a drainage basin o f 3*6 square miles at an average elevation of 695 ^eet above sea level. This is a higher rate of mean daily flood flow tlian that indicated for the area above the Diverting Dam at an average elevation of 350? feet. It is believed that this difference is caused by the different geological character of the two areas.* The Pacific slope of San Diego County may be divided into two *The discussion of the geological character of San Diego County has been based on the report of A. J. Ellis in Water Supply Paper kkS of the U. S. Geological Survey "Geology and Ground Waters of the Western Part of San Diego County California." -134- or 9S second-feet per square mile. Based on these figures, floods from the area above the Diverting Dam would be about 1.3^ times as intense as those f rom. t he area between the Diverting Bam and the Mission Gorge, The average elevation of the area above the Diverting Dan is 3507 feet; of the area between the Diverting Dam and the Mission Gorge, 151^ feet. Applied to the upper graph, Plate XIV, these average elevations in- dicate storm rainfall intensities of about 133*5 and 100.5 per cent of the mean for the total basin respectively. Based on rainfall intensities, therefore, floods from the area above the Diverting Dam would be about 1.33 times as intense as floods from the area between the Diverting Dam and the Mission Gorge, This figure is in substantial agreement with the ratio indicated by the flood flow analyses. Consequently, it would seem that flocd flows in the San Diego Hiver Basin above the Mission Gorge might be expected to vary directly with theintensity of the storm rainfall. The third record of flood run-off in the San Diego River Basin which has been analyzed is that of Alvarado Canyon at Murray Dam, a portion of the San Diego River drainage basin below the Mission Gorge. This analysis indicates a once-in-100-year mean daily flood flow of 505 second-feet or about lUO second-feet per square mile from a drainage basin o f 3*6 square miles at an average elevation of 695 feet above sea level. This is a higher rate of mean daily flood flow than that indicated for the area above the Diverting Dam at an average elevation of 3507 feet. It is believed that this difference is caused by the different geological character of the two areas.* The Pacific slope of San Diego County may be divided into two ♦The discussion of the geological character of San Diego County has been based on the report of A. J. Ellis in Water Supply Paper UU6 of the U. S. Geological Survey "Geology and Ground Waters of the Western Part of San Diego County California." -134- geological areas i the highland area of crystalline rocks, and the coastal belt of sedimentary rock. The boundary between these two areas lies roughly about 15 miles from and parallel to the coast. There are, however, intru- sions of crystalline rocks in the sedimentary area and deposits of unaltered sediment in the crystalline area. In the San Diego River drainage basin the first crystalline outcrops occixr in the dyke v/hich forms the Mission Gorge and the backbone of the divide v/hich separates the Alvarado Canyon drainage basin from the drainage basin above the Mission Gorge. It is, however, for the moat part overlain by the remnants of the Poway Mesa. In the U. S. Department of Ag-riculture, "Soil Survey of the El Cajon Area," most of the San Diego River drainage basin below Mission Gorge is classified as "Redding gravelly sand loam" and described as follows: "The limiting factors ... are ... shallowness and poor subdrainage ... has a 5 to lU inch surface soil ... subsoil is red clay ... very compact ... underlain at a depth ranging from 1^ to 3O inches by a hardpan like substratum of ... cemented material." The highland area of crystalline rock is largely made up of easily weathered granites. Disintegration in some places has taken place to depths as great as IOC feet below the surface. The soils are sandy and poroue. The above discussions of the geology and soils of the San Diego River drainage basin indicate that the granitic areas of the mountainous regions above the Mission Gorge with deep, sandy soils and disintegrated granites would absorb a much larger amount of rain before producing any flood run-off than the shallow soils underlain by hardpan which are found in that portion of the San Diego River drainage basin below the Mission Gorge. It is believed that this change in the geologic character of the drainage basin presents an adequate explanation of the higher intensities of run-off fotmd in the lower portions of the San Diego River drainage basin. •135- Tlie soils of the coastal telt from the San Diego River to the Mexican border are similar in profile to those in the San Diego River Basin and it is probable Lhat the flood flows at Miorray Dara might be used successfully in estimating flood flows from the coastal areas south of the San Die^to River drainage basin. North of Los Penasquitos Creek, however, the soil t;/pes chR,nge and are nrach more varied. Many of the soils are more sandy in character and the subsoils are more pervious to water. Consequent- ly, the flood flows from these areas would probably be somewhat lower than those recorded at M-orray Dam. However, from the apparent sizes of the smaller stream ch?>nnels and a stud;,' of the few records of flow available, it is be- lieved that the flood flcvs from these areas rould probably be at least as large, if not larger, than those from the lo'ver grauitic areas. Size and Frequency of Flood Flows . The probable sizes and frequencies with which flood flov7S may be expected to occur from each of the major draina- 10 O ^ • * CI OOOOOOOr^-NjoO • • fi - c c: & -H o o >, ir\r^r— O60ir\rH f-hijokn i-H 0) u^o:d- J- r- rH LpiU) ^■■^ (^ OJ •■M C o -— 1-1 c ir\ r-l >j o CJ V — ' I-H •H « tn OOOO OOOlTvOOO ;s ^4 ooooooooooo § ^ g U> O m O LTv r^NViD Lr\ 1-'^ 1 — -^ (B U >= OrHj-Ojr^O^ r-l t^VJD 6 o o O «'">■ o rH p " I-H "^-^ c3 «M OOOO OOOLTNOOO n COOO OOOCOOO ^ x; ^< r.-- Jd" C cS ^•»*»^*»*'^ ""* rH O (D iocjj-6ocr>or^ Loor- -a o >-. rj CJ rj ro r^ r^ rH CJ u^ c5 c •~^. ^ w O i-H o LPi "•'--' u c Ph -h OOOO OOOr^OOO 01 OOOO bOOOOOOO u r-r^OO r— ocnr^r— c^^^x) CO 03 cr^Lf^^ — , — \j:) r-{ c\i cj>cj<» >s I-H rH rH OJ CJ OJ rH CJ LO r-i rj '« ciKO ojLPv^-i — r-^Lr\f^r~- % c 0) o *■ • O 'jC Jd- VJD O LPi J- Cr\ CTv to o CO -tJ 4i CO 1-^ i. J- cr\ lJ-^ o w? >^ "^ ^ g 0) . g ^ C3 Q CS P Cjr^rHrHi^CMrH Cjr^g tu > Q CO ce rH -a! --• C . t:! ^— ^ ■H D H vi) •i-t Q) I^VX) (jN r^ r^,j5 ^-.j . rH OMjO ^< tn J-OLr^O Or--r^^-\bOJ-m - C O r— C\j r^ r^ rH r-^^ rH CJ V.O cS P! rH •* o &.H ^-^ rH ^H c/i S rH ^_ < ^ § i c c! 3 ^ e e HmdW)-H!:3a) ^+30 CO-a+a o-H >5-tJ 0)43 tU) d c C cjmow a c. u M <&\zi «5 •I-t t<4jjj4->. H.H cipicom u ■IJ a>cec3c3Pistos fH « c3 > +3 -P c8 o .Ht o pciQ)(DOcs3cvJn3c^ C yA > > > ^H ^ ca .r< .rl .H ^< h ^1 C ca O fn 43fL;cr;pia)(up •H > > > >j.H fH > U >» >^ O -H -H .H G W O -rj C!5 o CO ca o f>0 ■H Cf ce a •H r-\ O -139- a o i " >a O i-H •H cti tJ 0) 1 P OJ o S o I fn O O -^ 1 > W r-H f^ . CJ ,Q a r-H r-- 0) I— ' . OJ P, rH . OJ CM rH . CVI o o^ o CJ I- . 0. O CJ^ (D 1— I f-H i-H • CJ o CJ GO ^1 CT^ r — CJ VD . r-H 1-3 o rj o> CjCi rH J- CO CO to L.-N CJ CJ CJ co J- VJD 1^3 r — o CJ O CJ to J- CM Lr\ cr> CJ a> CTi CJ J- r^ CO CJ CJ CJ NO cu 60 1^ ro J- CJ> cc o r — LTv » CM o CO o o CJ rH CM 60 CO >-£) 60 o CM CJ O K^ CJ 60 60 O CO K£i (J-- CM OJ a> a) c o nJ - (D ci a a* -H ^H fn 03 M E <3j -d ^ 0) n3 (U U3 CO >.o r^ r-i VD LP. LT, t^ u-% Q t. O CJ 1 — r^ MD cn J- rH CJ r^ r-O t-^ ^ LO ITN UD N- o o rH I O i-H a) 03 a Pi o +> 03 » H 0) 0) iJ CD 03 Pi P4 > 5 > S a o > C S fn T) +3 « « n r^ o o; 03 WPi T) >aO crt u ^ •H trt ^ 03 > S > 03 ■ rH « nH rH o rH -d PI & >. 01 o 03 03 Pl -rH o •H •H >, OJ C3 !>3 o Pi 03 01 -tJ CO 0) hn o cd •H !n d 03 o ;i ^ O >^ Ph o3 w •iH w 03 ^■^ fe 03 ):--^ D CO -H o n3 S CO c ^ *^ ;:l •H •H •r^ ;:! Pi Cd o 01 +3 -iJ -u i-l += « +J o 43 O 4J « +3 1^ +3 (d +> +» +» +J ■P -!-> •Tf OJ 01 01 OS 03 ClJ 01 01 01 > rf c rH 03 nJ +3 o 03 G 01 01 § g % § % -aj W o w w 10 in EH CO CO CO p:; P« C Pi (U O 03 > >i > o o3 43 -d +» •H Oi Pi O Oj Pi M rH P. -H 1^ P< P. 03 03 > > •H -rf p:^ PI ' O o Pi Pi 03 rO Pi rH 0) 03 03 43 ■H N OS 43 •H o3 Pi U cS o tiO 03 5U) "d P< Q p. H rt 43 oJ 43 43 o3 +3 03 c a a 03 CO CO o3 s Pi r; 03 03 0) o3 43 s:: +3 a a 03 03 CO CO 03 03 ■14u- PLATE XVI 5 o E E B x (0 E CL C o o O (NJ O) E E E x e Q. 5 o E J X £ 300 2 50 200 150 100 50 300 250 200 150 100 50 ' '1 at 308 ALVARADO CANYON AT MURRAY DAM DRAINAGE AREA 3.6 SQUARE MILES 1 i 1 1 1 1 A V A A , 1 K V \ ■ V, ;:c: \ ^ "-■x ^ 3 SWEETWATER RIVER SWEETWATER DAM DRAINAGE AREA ISI SQUARE MIIES r T ^ i I-' '•1 1 '■-1 .. 1 i 1 r-' / ^ i xf 15 10 5 Hours before crest 5 10 15 20 25 Hours after crest LEGEND Flood of April 6, 1926 •• 7, 1926 " 8,1926 Feb. 14,1927 " 16,1927 Jan. 17,1916 '• 27,1916 Mar. 12,1918 Dec. 19,1921 Dec. 20,1921 Dec. 26,1921 Mean Flow HYDROGRAPHS OF FLOODS IN STREAMS OF SAN DIEGO COUNTY 5 10 15 20 25 Hours beforj-g ^^g^-^ Hours after crest PLATE XVI 250 TEMECULA CREEK •T Nt66ER CANYON OUINtGf AflEA 371 SQUARE MILES 160 / A / \ A 100 '\ / N \ / (^A \\ • \ A \r - \ y ^^\ \ // ■J \ ^ \ I- :$: <- \ ^ n H 1 1 , T SANTA MARGARITA RIVER DELUZ OMmAQl AREA 710 SgUAflE MILES ^ 1 \ ji Hi \ { 1 V- ^J SAN LUIS ^REY RIVER OCEANSIDE DRAINAGE AflEA SES SQUARE MILES 1 ^^ ^>< .^ 'r ^ N<::^' ^^'"- '"-- ^ •Jf "^^ ~— , -- ,^' 150 100 SANTA MARGARITA RIVER RAILROAD CANYON ORAtNAGE AREA 593 SQUARE MILES V J w / ^\ / u iJ\ '^ h ^ ~\ 1 \ \ x/ ^J '\ ■^v. s. SANTA MARGARITA RIVER ! YSIDORA DRAINAGE AREA 749 SQUARE MILES / i \ /- ^^ .7 \ ^ s. "^ ^ \ \.^ -- Peak Prak Peak ar4ZS aT3?0 RT328 •/'-I t SANTA YSABEL CREEK '•'■■^ 1 SUTHERLAND DAM SITE %^ \ DRAINAGE AREA 5* SBUARE MILES 11 11 ^i V 7^ \'\ ^- \: r^ ^ 'i*^- 1 SAN DIEGUJTO RIVER HODGES DAM DRAINAGE AREA 30J SQUARE MILES ' '""n k K \ '>}. / 1 J %s^ ■\y i H 5 10 15 20 Hours afier cresi 15 10 5 Hours before crest SAN DIEGO RIVER SAN DIEGO DRAINAGE AREA WS SQUARE MlUS ■/' \ i if/ \ '--J ( \ '\y\ ■>< " ■ — 1 Peak a1 308' ALVARADO CANYON MURRAY 0AM DRAI ACE AREA 3-6 SQUARE MILES \ 1 i \ } f \ ■o»^ wt \ / ^ X "" - '-" SWEETWATER RIVER SWEETWATER DAM DRAINAGE AREA IS) SQUARE MILES i' i L| 1 J _^ 1 1 MEAN FOR STREAMS SHOWN \ / \ / \ / / \ N. ^ 15 10 5 Hours before crest 5 10 15 20 Hours after crest S 10 15 20 ttours after crest 25 IS 10 5 Hours before crest 6 10 15 20 Hours after crest LEGEND Flood of April 6. 1926 •• 7, 1926 » 8,1926 " Feb. 1 4, 1927 •■ •• 16,1927 •• Jan. 17,1916 " 27,1916 X Mar. 12,1918 •■ Dec, 19,1921 •• Dec. 20,1921 ■. Dec 26,1921 Mean Flow HYDROGRAPHS OF FLOODS STREAMS OF SAN DIEGO COUNTY 25 15 10 6 HoLjrs before crest 5 10 15 20 Hours after crest Tlie crest flow of each flood sho-m on Plate XVI expressed as a ratio of the mean daily flo.v has been liste:'. in Table 28 in the order of magnitude of the drainage basins. In the last column of Table 28 are listed the average crest-mean daily flow ratios for each dr-dnage basin and in the last line are listed the average crest-mean daily flo^7 ratios for each storm. It will be noted t'nat althou^'h the averages by drainage basins indicate a considerable reduction in the crest-mean daily flow ratio with an increase in the size of the drainage basin that the crest-mean daily floi? ratios of the smaller drainage basins are based on a different gro-a-p of storms than the ratios for larger drainage basins; that the mean ratios for the floods of record on the smaller drainage basins are considerably higher than those for the floods of record on the larger drainage basins; and that in the floods of January 27, I916 , and February 17, I927 , the tv;o largest floods of record, with iiydrographs available for both large and small drainage basins, the indicated decrease in the crest-mean daily flov; ratio between drainage basins from 100 to 700 square miles in extent is but slight. An analysis attempting to factor out the effects of the variations of individual floods was made. However, the inaccuracies of the data, previously discussed, were no great that a satisfactory solution could not be obtained. For these reasons the flood hydrographs which have been used in this report have been based on combin- ations of recorded flood hydrOy-:raphs of streams in or adjacent to the drain- age basins considered, selected arbitrarily after consideration of all the factors involved. The probable sizes and frequencies of occ^orrence of the crest flows of each of the major drn.inage basins in San Diego County are listed in Table 29. -141- The crest ilow of each flood shovm on Plate XVI expressed as a ratio of the mean daily flow has been listed in Tahle 2?? in the order of magnitude of the drainage basins. In the last coluinn of Table 28 are listed the average crest-mean f.aily flow ratios for each drrdnage basin and in the last line are listed the average crest-mean dailj'' flow ratios for each storm. It v;ill be noted tliat althoiagh the averages by drainage basins indicate a considerable re^luction in the crest-mea,n daily flow ratio vvitn an increase in the size of the drainage basin th,at the crest-mean daily flow ratios of the smaller drainage basins are based on a different croup of storms than the ratios for larger drainage basins; that the meazi ratios for the floods of record on the smaller drainage basins are considerably higher than those for the floods of record on the larger drainage basins; and that in the floods of January 27, I916 , and February 17, 1927, the t'.vo largest floods of record, with liydrcgraphs available for both large and small drainage basins, the indicated decrease in the crest-mean dailj'' flow ratio between drainage basins from 100 to 7OO square miles in extent is but slight. An analysis attempting to factor out the effects of the variations of individual floods was made. However, the inaccuracies of the .lata, previously discussed, were so great that a satisfactory solution could not be obtained. For these reasons the flood hydrographs which have been used in this report have been based on combin- ations of recorded flood hydrov'-raphs of streams in or adjacent to the drainr- age basins considered, selected arbitrarily after consideration of all the factors involved. The probable sizes and frequencies of occurrence of the crest flows of each of the major d.r,ainage basins in San Diego County are listed in Table 29, ■141- (AJ W « w o (J o o o o (I (_. o o o o O n) o r- ir\ q OJ r-<^ q LO o 0"v Ox r-i 1^ CO ftO rH o^ r-H OJ +3 OJ >w^ tD 0) o 6" ' 6 " 6 ' 6 " 6" C) o o o o o o -d K fH 60 o ^ Ui ^^ o C -H 0) •* ^ ^ •* O a) cu 60 60 rH OJ r-t o o ^ vn LPi CO r— ^ OJ 0) o •— s y~^ rH (0 c o I— 1 OJ o o X a i-H c " 6* " 6" " 6 '" o o " o & ^. 00 o O o o o O o u f^ ^x> cr kO U3 vo O nS " " " OJ -Ji- i-H J- VD ar- o O !>: J- ,tt vo ^ ea ty- +J o ^—^ C3 o I-H ou a' m >_-- o '" o ■■6' * o ' o ' o " O (.1 o o o o o o tr\ VD (Tn q r-\ q O CO ir> U3 a-. o >= r^ rj -tf OJ rH J- LO, r-l OJ CJ ^ H & d o Q> r-l Lr\ 60 o VX) r— • o S ^ LPn UD r — LTA c^^ J- r-H rH 1— 1 rH r-l rH OJ rH +3 • — » ,^^ — CJ rH I-H rH CVJ ^ >!»<:: ^^^ H <=lj r-H -H r-H o ' a H O r^ a> t^ U~\ r-i 60 ^ CO ^ ir\ l_^ K^ CO LTi " ci o ci :^ r-t r^ r^ K^ ^ rH "■n 0) a<-H r— 1 rH t4 m g v_^ ■=j! nJ l' ^ o m o nd W ^1 t:) •H OJ •H W CO O +J 02 3 H ^ o & o w •H -p +J -|J o o « « 01 fi k3 o m 0) 4-5 n3 •r-l ^1 fn 4J o3 CJ « 0) O rt c ^ d > ■ H > ■H ;h !~i i:^ +» « « (U > 0) •H •H > ■H > a fl >■.. o •H Ph •H u 03 W W « e>o K •^ ^4 fn O QJ o3 J3 CO t^O tlO +5 s •rt (J o nJ m JU •H •H ^ p n3 I-H o Q 4i >-s +5 (J c c § c (U c3 03 03 oJ & •H in to CO CO CO Eh ^ -H o rH -d Vi 0) +J >. en rH -H •H rH cd "d 0) 3 1? 0) >> B 1 0) ■»^ ^ m 4J o r-t m Cm •H Xi h +^ Oj a> a >s •rl 1 6 'd Lr\ 0) OJ 'd I fS fi rH -H O I CI CD •H O S3 C O ffl (D CD ^ • ^ 4J s Ui t,_. (^ 03 o .a !s & 01 fH O ^ •H rH en O Ch C > (Ij ?H >v> W Ph "d O 1 ^ C h c« oJ 03 +a C •H B •H P4 cn t« "d 01 o o ^ •H rH Ch (D P^ -H 1»I) -d 01 CfH O c o B •H 01 -P (U ^^ o ^ t:) t( •H to 01 ■!-> 03 o3 ^ (\n d c p CO r — •rl hD -H OJ Id 0) fn O (D r-i •H rH o (D +J ^ p^ (fl n3 03 EH ;h £4 OJ ■142- Effect_o_f £onservati_on__Re_servoi_rs- The crest flood f lov/s listed in Tabic 29 are based on analyses of the natural flo7/s in the streams of San Diego County. The construction of conservation reservoirs v;ill change the charac- teristics of these flows to some extent. In the operation of conservation reservoirs the reservoirs are filled as soon as is possible each year. After the reservoirs are filled the flou of the stream is passed through the spill- ways of the dams. In passing through the spillvjays the crest flows are re- duced some-jhat by the temporary storage required to build up the necessary head over the spill7?ays. It has been estimated that the construction of the El Capitan Reservoir on the San Diego River will reduce the crest flow of the once -in -250 -year flood at Old Town about 21 per cent. The construction of the San Vicente and Mission Gorge reservoirs to capacities of 174,500 acre- feet and 29,200 acre-feet respectively as discussed in Chapter VI would in- crease this reduction to 37 per cent. The effect of full conservation de- velopment would be greater on the lesser flood flows. Analyses, of full con- servation operation discussed in Chapter VT^ indicate th;\t there would be flow past the Mission Gorge Reservoir only about once ev3rj' three years on the average; that there would be no contribution to the crest flow of the once- in-25-year flood at Old Town from the area above the Mission Gorge; that reservoirs would probably hrive filled prior to the occurrence of floods with expectancies at intervals -greater than once in 50 years and that the only effect of the upstream storage on such floods would be the regulative off jct of their passage through the spillways. The result of this conservation de- velopment, therefore, viould be that for periods of over 25 years in length the crest flood flows at San Diego would be only the comparatively small flows from the 59 square miles of drainage basin below th3 Mission Gorge biit that once every fifty years or so a flood would occur from the 435 square miles of the San Diego River drainage basin. Such a regimen might very easily -143- result in a fnlso sense of security and lead to a major flood disaster at soma time in the future. Methods of Flood Control . Many of tho str.om ch-.nnols are at present grovm up with 7;illous and other brush end. trees ':7hich impodi the flov; of smaller floods and may cause p. major flood to cut ne'.v channels. The removal of those obstructions and the straightening of normal channels would increase the velocities of fl077 and reduce tho tendency to deposit debris. The channel straightening uould probably necessitate some bank Tireteotion at vulnerable spots. It is probable that by means of Ciiannel cleaning -nd straightening vjith some bank protection, the natural channel capacities of most of the stre'-ms would be increased sufficiently to h-;.ndlc floods which might be expected to occur at average intervals of about 25 years with comparativelj'- little daiaago to adjacent lands. Additional flood control and protection of lands subject to over flow may be accomplished by the construction of levees to confine the flow to selected channels. However, the heavy gradient of most of the stream channels causes high velocities on large flows, which require costly pro- tection for the water slope of the levees to prevent erosion and to insure their safety. Adequate drainage must also be provided for side streams and run-off from the areas behind the levees. Flood control by means of channel clearing, bank protection and levees only, contemplates the necessity of rjroviding channel capacities adequate to handle the natural crest flood flours of tho streams. In San Diego County, however, although the crest flood flows are high, they are relatively short in duration. The average flood hydrograph, shown on Plate XVI, indicates a crust flood flow 2.15 times as large as the corresponding mean -144- daily flow. Flood periods, the product ol" excessive rainfall, seldom last more than three days. Consequently, il; is possible through the storage of excess flow in a relatively small amount of reservoir space to reduce materially the size of ths flows which may be expected to occur in the lower stream channels. In the average flood hydrograph shovm on Plato XVI with a crest flow 2,16 times the mean daily, only 10^ of the total flow occurs at a rate in excess of 1.25 times tho moan daily, \l'Ja at a rate in excess of the mean daily, SOJij at a rate in excess of 0.75 times the moan daily and 50-;^ of the total occurs at a rate in excess of SOyfc of the mean daily flow. Thus, with available reservoir space of only a little over 17;t of the mean daily flow it would be possible to rcduco the crest flood flow of a flood with these ckiracteristics to only one-half its natural size; or, with available reservoir sp-.ce equal to about 50^ of the moan daily flow it would be possible to reduce the crest flow to about one-fourth its natural size. It is obvious that the reduction in size of crest flows by control of the discharge from a reservoir reduces the menace of flood flows to tho dov,'nstrer-.;ri valley lands. In addition to the above described raethods of flood control by channel improvements or by use of reservoir storage space, a combination of the two affords a third solution. The most economic method may be determined for any specific area by a study of comparative costs of reservoir storage space and channel improvement by levees. Utilizj^ti_on. 2.f_Con_3e£v_at_iqn R&3f5£Voi£s_f_or_F'l_ood__C_ontrol- In San Di ago County the limited quantities naturally available and the value of water are such that all of the most economic reservoir sites may eventually be needed for conservation purposes. If any reservoir sp-ace, therefore, is to be pro- vided for flood control it will probably have to be in connection with a conservation reservoir. In the Sacrajnonto and San Jor quin valleys it h"s been found possible to combine thn use of reservoir space for both conservation -145- and flood control purposos. In these arr-is v;hore, as in Sr.n Diego County, the major floods TTsre found to occur only in tho vintar months cis the direct result of r-iin- fall, a previous investigation found that rules of reservoir operation could be established Tvhich -^ould p:;rmit the joint use of rjsorvoir spr.ce for both conservation and flood control purposes. These rules uero b.iscd on the time of year and on the amount of seisonal precipitation to date. They arc des- cribed fully in the report* on the control of floods by reservoirs. Briefly, they consistod in establishing tho limiting dates of the flood season and in reserving space for flood control purposes Tvhenever the tot"l rainfall to date during the fl:)od season reached a set porceut'^ge of the normal rainfall to date. With such rules in force it was found that floods might be controlled and that any empty space in the reservoir at the end of the flood season could be filled by the run-off of the late spring and e-^rly summer. The maximuiTi mean daily flood flow's of the San Diego Riv^r at Mission Gorge have been listed in Table 30 T7ith tho total rainfall at Cuyamaca prior to the fifth day before the flood expressed in the percentage of normal to that date, or the rainfall index. The rainfall indices for the floods of January 1895 ajid February 1891 have b-^en included because of historical evidence that these floods ;:ere above normal in intensity. In- spection of tLis table indicates tnat major floods on tho San Diego River may be expected to occur only vihsn the precipitation to date is equal to or above the normal precipitation. It has been previously shown that major floods may not be expected to occur after April 1st. A logical rule for flood centrol operation on the San Diego River, therefore, nould be as follo7?s: -maintain * Bulletin No. 14, "The Control :-f Floods by Reservoirs," Division of Engineering and Irrigation, 1928. ■146- ros.jrvoir sp.ica for fljod c:)ntrj.l whenever the rr.infall index is 100 it ovor prior to April 1st; after this date close the flood control ports and allow the reservoir to fill. The use of conservation space for flood control purposes without impairment of the conservation value on the San Diego River, therefore, is dependent on the possibility of filling the space reserved for flood control with the flow subsequent to April 1st. The estimated full natural flows at Mission Gorge for all years in which the rainfall index at Cuyamaca was 100 or more on April 1st are listed in Table 31. It has been pointed out above that with a mean hydrograph as shown on Plate X7l,the crest flow could be re- duced 50 per cent with storage of only 17 per cent of the mean daily flow. This percentage, applied to the estimated mean daily flood flows at the Mission Gorge as listed in Table 27 would require 15,600 acre-feet of reservoir space for control of the 1-in-lOO-year flood and 18,700 acre-feet for control of the once-in-250-year flood to 50 per cent of the crest flow. An inspection of the data presented in Table 31 shOT.'s that in ten of the seventeen years in which space would have been required for flood control prior to April 1st it vrould have been impossible to fill even the space required for control of the 1-in-lOO-year flood after April 1st for conservation. Furthermore, in 1897, the last flood year prior to the dry period which ended in 1905, the run-off subsequent to April 1st was only 900 acre-foet. Consequently, it is believed that the use of conservation space for flood control purposes is ioipracti cable in San Diego County. However, many of the reservoir sites on 3an Diego County streams have potential storage capacities in excess of the conservation requirements. It is, therefore, possible to provide reservoir space for flood regulation in reservoirs built primarily for conservation uses by increasing the height of the dam and the total capacity of the reservoir. In a reservoir built for -147- TABLE 30 RELATION OF MAJOR FLOOD FLOWS TO PRIOR PRECIPITATION FOR SAN DIIilGO RIVER BASIN ABOVE MISSION GORGE Total precj .pitation at Cuyamaca from July 1st Date of flood Mean daily flov?, in second feet to date In percent of Date normal total to date Feb. 23, 1991 Feb. 13, 1391 123 Jan. 17, 1805 Jan. 12, 1895 129 Mar. 25, 1906 6,300='' Mar. 20, 1903 109 Jan. 17, 1916 12,500 Jan. 12, 1916 102 Jan. 27, 1916 35,000 Jan. 22,:. 1916 197 Mar. 12, 1918 5,400 Mar. 7, 1913 51 Dec. 26, 1921 15,400 Dec. 21, 1921 210 Feb. 16, 1927 19,400 Feb. 11, 1927 107 * Estimated from record at Lakeside, TABLE 31 FULL LIATURAL RUN-OFF OF SM DIEGO HIVER AT MSSION GORGE SUBSEQUENT TO APRIL 1st IN SEASONS IN '^'KICII TIiE RAIJMFALL INDI'J. WAS ABOVE 100 Full natural flow Season : Rainfall index at Cuyamaca : at Mission Gorge on April 1st : subsequent to April 1st, in acre-feet 1888-89 : 138 : 12,600 1389-90 • 194 900 1890-91 152 7,300 1392-93 124 4,000 1S94-95 150 7,500 1895-97 11? 900 1900-01 Ill : 1,800 1904-05 138 : 15,900 1905-06 145 : 31,900 1906-07 122 • £2,100 1908-09 133 : 12,300 1914-15 118 : 42,300 1915-16 166 : 21,900 1919-20 102 : 12,200 1921-22 154 : 31,400 1925-27 174 : 22,700 1931-32 149 : 7,500 -148- both flood control ind coasorvrtion purposes, tho lo^.'cr portion of the roscrvoir spnco providjd .vould bo dodicatud t:> cons.TVc.tion uses and the upper portion of tho sp"ce provided \?ould bt usod for flood control purposes. Any outlets through tho dnai would bo so controllod that -hen the vjr.ter surface in tht roscrvoir r/as bjloT? the conservation level there would bo no wr.stuful discharge. Flood outlets r.nd spillT/ays T70uld bo designed to automctically control the flood discharge to predetermined flows. Since the area over which the flood control storage "r/ould take placj would bo large, an incrsaso of only :: few foot in the height required for conservation dams should provide adequate spaco for a considerable re- duction of flow on most streasis, ^tat'as_ of_ ?lood_Pro tec tion in _San Diego Couaty. Comparatively few permanent flood control works have been con- structed on the streams of San Diego County. On several of the streams short stretches of bank protection works have been installed. On the San Diego River, the Federal Government in 1377 constructed a dyke runnias from Presidio Rill in Old Town to the high gro\ind of Point Loma, for the purpose ::)f per- manently diverting the San Diego River into Mssion Bay. According to Williair E. Smythe,* the river emptied into False or Mission Bay when the Mission and Presidio were established in the latter part of the 18th century, but in 1821 or 1825 cut through into San Diego Bay .and continued to flow there with only oue slii:ht interruption imtil the completion of the government dyke. The river carries large qu3ntities of silt and sand when in flood and was steadily shoaling the harbor of San Diego Bay. The dyke was constructed under a Federal appropriation of •■J80,000 and has been raised and strengthened twice since its construction, the first time soon after the 1916 flood and the second time in 1933. *History of San Diego, 1542-1908," by William S. Smythe, 1908. -149- On the Santa Margarita River some bank protection nork and a Icvgg have b>ion constructed by the ov;nors of the Santa Margarita Ranch near the head of the upper basin in the vicinity of O'Neill Lake. The County of San Diego in cooperation v,'ith landowners has constructed a small aaiount of tetrahedron bank protection along the San Luis Rey River about two miles up- stream from San Luis Rey Mission to protect the adjoining farm lands and prevent the river from changing its channel. On the San Diego River near Santee, a 7/ire and rock mattress bank protection has been constructed on the left banic by the County of San Diego to prevent the stream from eroding the lands of the county farm. On the Tia Juana River, the County of Son Diego in cooperation with local property owners has constructed a levee approximately one-half mile in length to prevent the flood flo7;s of the Tia Juana River from crossing the loT7 saddle near Nestor and flowing into San Diego Bay. Channel cleaning and straightening has been done on some of the streams of the county during the past year. In 1933 the channel of the Tia Juana River was cleared of brush and plowed from the international boundary downstream for a distance of nearly four miles by the State Division of Forestry and County of San Diego. In the winter of 1933-34 the channel of the Santa Ysabel Creek in the San Pasqual Valley was cleared of brush and trees as a C.W.A. project under the County of San Diego. The San Luis Rey River channel near Bonsall is being cleared under an SERA project and bank pro- tection is being constructed at points where the destruction of improved farm lands is threatened. F_u_ture_Flo_od Con_trol Works.- In considering the problem of flood control for San Diego County streams, it has been shown that the lands subject to over- flow are a very small part of the total area of the county. From an inspection of Plate XII, it can be readily seen that most of these areas are comparatively -150- lonG and narro'v. This moans that each milt; of channel protection would re- clai:n but a smill acren:-o of land. From the experience of the 1916 flood, v'hich caused R:reat damago to these valloy lands and destroyed many improvements, few residences have been built below the flood plane and r.iost of the agricul- tural lands have been used only for annual crops since that time. It may also be pointed out thc.t v/hile the major floods may cut away valuable lands or destroy others by depositing coarse sand on them, in other parts of these valleys silt is deposited and these areas improved in quality. In Watar-Supply Paper No. 446,* Arthur J. Ellis states: "Within very recent geologic time tho laud has stood considerably higher than at present, and there are indications that along most of tho const sinking is norr in progress. This sinking, possibly hot; in progress, is shoTjn by the partly drowned and consequently marshy vrllcys of all streams thr..t reach the ocean in this part of the country." This sinking of the land in relation to sea level would re- duce the stream gradients and .account for the deep alluvial fills of tho lower valleys. The gradual building up of the volley floors may be indicated by the testimony of l^^ndovmors in the overflov/cd areas, -/yho report fences in the river bottoms being partially buried by sand and silt and the silting of one to three feet in depth in brush areas by major floods. Minor floods also deposit silt in brush areas along the- stru.am cha.nnel. This ;7ny result in a cycle of alternately eroding good agricultiiral lands and in silting up other sandy brush-covered areas ^vith large loss to the individual landowner but -/^ith a net loss to the cornraunity of the cost of improvements. It also may result in the tendency of the stream to shift its channel location because of the building up of a ridge adjacent to the channel through deposition of debris in *W.S.P. No. 445, "Geology and Ground Waters of the Western Part of San Diego County, California," by Arthur J. Ellis and Charles H. Lee, 1919. -151- brush, covered areas. The infrequency '"ith -..'hicb the major floods occur allows the streeun channels to beco-.Tie groT/n up Trith brush and trees durinc the long intervals of comparatively lo:? flov;s, and tends to force the large flovs aray fron the old channels and into ne-: ones. The maintaining of cleared ch.-nnels vjould reduce this tendency of the stream channels to -Aander and mght result in erosion of the channel bottoms Tvith resultine higher banlcs and gr^^ati^r channel capacities. The volumo of major floois flo-.-'s is so great in these streasis, and due to the steep gradients of the stream beds, of such high velocity that the rater face and toe of levees built of riverbed materials iiust be adequately protected to prev;nt orosion and failure of the Icvogs. This greatly increases the cost of a levoo system. The narro-:? ridth of tho valleys in comparison with ths length of levoos necessary to protect thorn -ill rosult in a high cost per acre of land protz^ctod. 7ith full rater -development of the streams the additional storage, as has been sho^n for the San Diego River, ■.•i.ll materially reduce the crest floTTs of the minor floods and result in protection from floods of from once in trrenty-five years to possibly somer.'hat longer frequency. In general, this protection is very probably as great as could be economically justified ">vith the present values of agricultural lands. Ho'vever, as has been stated earlier in this chapter, this might result in a false sense of security, and encourage the construction of permanent improvements or residences belo™ the flood plane. Until adequate flood control '^rks are constructed, it should be borne in mind that the valley floors are subject to inundation and that any permanent improvements in these areas are liable to damage from major floods. It has been previously shoun that flood control may also be accomplished through use of storage capacity above a conservation reservoir -152- through design of dam and spillnay for that piirposo. Consequently, it is bclioved that in the future construction of conservation reservoirs, especially those located on the loT7or reaches of the streams, a car^iful study should be made of the possibility of adding flood control features and of the resulting benefits to the lower valleys throu;:h the additional flood pro- tection that may be accomplished in this manner. It is also believed that proper maintenance of clear channels with bank protection at the more critical points may be accomplished at relatively small costs, and T/ill materially reduce the dama^;e liable to occur in major floods. P rotection of Tia Juana River Valley . In the Tia Juana River Valley bet'jeen the international boundary line and the Pacific Ocean, a total of some 4670 acres are subject to over- flov? in time of flood. Of this area 960 acres are marsh land trith but little present value and little future agricultural valuo until the deposition of debris shall have raised their elevations several feet. About 700 acres are river v/ash in the main channel of the river and have no present agricultural value -.Thatever. Under any system of flood centrol approximately all of this latter area -7111 alr/ays be needed for river channel. There are about 1,150 acres of class 3 soils, at present 1 .rgoly cov'jred rath brush or utilized as pasture "'hich lie along the sides of the mriin channel and are nor.- subject to frequent flooding. These soils are largely classed as "Cajon fine sand" and described as follov;s: "The surface soil.... consists of .... fine sand or very fine sand .... The material below the surface soil is of the same character but may be variable in texture. Nonially some calcium carbonate occurs in both the s-arface soil and subsoil, although the amount may be very slight in some of the more recently deposited soil. This soil represents -153- very recently deposited soil material or material that is being deposited durinc unusual floods. The humus content is low and the soil holds very little moisture. ...alfalfa and truck crops are grown." The remaining 1860 acres are class 1 soils predominately classed as Foster very fine sandy loam - gray phase. They are described as follows: " ... extremely high in mica, very floury and easy to till. Some calcium carbonate may occur in the surface soil but a greater amount is in the subsoil. The soil has a fairly high water holding capacity and is easy to irrigate ... highly desirable for alfalfa and truck crops." About 900 acres of this area altho\:gh subject to flooding are so located that there is very little probability of their erosion or of the deposition of coarse sand or debris by floods. The rest of the class 1 soils and all of the class 3 soils, about 2110 acres of agricultural land in all, are in more or less danger of erosion or debris deposition whenever unusual floods occur. The estimates of probable crest flows in Table 29 show that a flow of 40,000 second-feet may be expected to occur about once in 25 years on the average and one of 30,000 second-feet about once in 50 y^ars and a flof? of 121,000 second-feet might be expected about once in 100 years on the average. The average slope of the valley floor from San Ysidro to the ocean is about 10 feet to the mile. Since the flood of 1916 the valley floor has been practically uninhabited. However, at the present time, residences are encroaching on the flood plane particularly in those areas r/hich wore not seriously flooded in 1927. If the valley floor is to be made safe for residential purposes these areas should be protected against floods of at least l-in-lOO-year expectancy. A topographic map of the entire valley floor frou the international boundary to the ocean was made during this investigation, and studies v/ere made for reclaiming this area. A leveed channel 900 feet wide between the toes of the -154- Iev30s and viifAi Icvass about 11 fs^t high would provide such prot.iCtion. It is astimatod that such a channol would cost slij^-htly ovsr $1,000,000,00. It would provide protection to somo 3000 acros of agricultural land, enabling the farmors to live on th.:ir farms or tho devolopmjnt of thj area as an urban ccntor. Thsra is, ho:;ovcr, no particular need of this area for urban purposes, nor with large suitable residential areas within a ferr miles is it necessary for the farmers to live belo\7 the flood piano. It is estimated from the County Assessor's valuations that the actual present vnlua of land and improvements subject to flooding is a^iproximately $500,000, and that the area subject to possible erosion or debris deposition has an actual present value of about $160,000. Consequently the large expenditure necessary to reclaim these lands is not economically justified until the land values greatly increase. -155- CHAPTER VI CONSERVATION AITO FLOOD CONTROL 70RIiS ON SAN DIEGO RIVER The plan presented herein comprehends the most economic development, conservation, utilization and control of the water resources of the San Diego River for all consumptive purposes, and flood control, in coordination with existing developments. The very existence of a permanent civilization rests upon a dependable and adequate water supply. As the water supplies naturally tributary to San Diepo County are deficient in amount to meet the ultimate demands for complete development of the county, it is essential that in the formulation of a plan for complete development of the water resources of the San Diego River or other streams in this county, the plan must be based primarily upon conservation and utilization of water for domestic, municipal or irrigation purposes. All other possible uses of the works of the plan, such as flood control, power or recrea- tion must be necessarily incidental and secondary. In determining the best plan for the development of the San Diego River, no consideration has been given to the possibility of storing v/atcr imported from other watersheds in reservoirs constructed v/ithin the San Diego River Basin. Should such importations be made, provisions for storage of that water will modify the physical -jorks as set forth in this chapter, and the operatioa thereof. A decision of the Supreme Court of the State of California has confirmed the paramount right of the City of San Diego to the waters of the San Dieero River. The construction of additional storage works on this river -156- Till present no different legal problems than may arise from the construction and operation of El Capitan Rcsorvoir. Thoruforc in estimating the cost of physical works for the full dcvolopracnt of the nator resources of the San Diego River, no alloirance has been made and no costs included for water rights or litigation arising therefrom. Although other types of dams may be used and were considered for some of the dam sites in the San Diego River Basin, gravity concrete dams, straight in plan, have boon used at all sites for estimating capital and annual costs, and unit costs of storage and of safe yield. While all sites considered are suitable for certain other types of dams and the substitution of a different typo of dam for use at all sites may result in reducing the estimates of cost, the comparative merits of thtj different sitas -./ill not appreciably change. The economic factors involved in the determination of the best layout of physical -.vorks are not primarily dependent upon the particular type of dam I selected for comparison of the several sites and of various hcipr^ts for any particular site. Existing Devolopment The most important existing v^orks of development in the San Diego River Basin are the Cuyamaca Reservoir, Diverting Dam, conveyance and f order flumes. La Mesa ditch, and Eucalyptus, Grossmont and t;Iurray reservoirs, all of i Thich belong to the La Mesa, Lamon Grove and Spring Valley Irrigation District; the El Capitan Reservoir recently completed by the City of San Diego for its ' water supply; and the government dyke near Old To'^m. The Cuyamaca Reservoir is located on th'-. hcadraters of Boulder Creek at an elevation of about 4600 feet above sea level. It is formed by an earth fill dam 665 feet long and 40 feet high vath spill-rays at both ends, and has a capacity of 11,600 acrc-fect. A more detailed description of the reservoir is •157- given later in this chapter under "Conservation Reservoirs". I7ater is stored in the reservoir for diversion to tlie irrigation district through its flume. The Diverting Dam for tho irrigation district's flume is located on the main San Diego River a short distance bolou the mouth of Boulder Creek. It is a masonry dam 510 feet Ion;? r?ith a maximum height of about 30 feet above a stream bed elevation of 770 feet* The two spillway sections, which are in the crest of tne dam, have a total length of 220 feet and their crests are about 6.5 feet bulow tho average elevations of the tops of the abutments of the dam. The side slopes of the dam are approximately 0.1:1 upstream and 0.3:1 downstream and the crest is about 3 feet thick. There is one 30-inch square sluiceway near the- bottom of the dam at the center of the channel and a 24- inch square sluiceway below the flume outlets. Thore are two 24-inch by 36-inch outlets for the discharge into the flume. The flume is of •.vooden construction for most of its length and is set on a bench along the mountain side. Its bottcxi is about ten feet below the spillway crests at the Diverting Dam. It follows th>i left side of the river canyon fron the Diverting Dam to the El Monte Tunn'!;l, about two miles east of Lakeside, and then turns to the south and follows around the El Cajon Valley to its terminus at the Eucalyptus Reservoir near th'„ tovm of La Ifesa. At several points, including the South Fork and Ch:)colate Creek crossings, the original flume has been replaced by concrete or steel pipe syphons and in other places by semi-circular metal flume. Also, at several points, the conduit passes through points of rock and under divides or ridges in tunnel. At the present time the irrigation district is replacing the old flume from El Monte Tunnel to its terminus with reinforced centrifugal concrete pipe. The feeder conduit from the South Fork empties into the main flume just below the South Fork syphJn. It is constructed partly of semi-circular metal flume -158- and partly of 20-inch steol pipo. After the El Gapitan Rcsi^rvoir has boen fillod, the entire flume and fcsder system above tho El Monte piimping plant, near Lakeside, rvill be aband:!nod, as part of it v.- ill be submerged by the water in the rcservjir. After that timo, all iiTatur vill be convoyed frcm the reservoir through a pipe lin^ to bo constructed j lintly by the irri^.-iti.n district and the City of San Diego to the El M.--nte pumping plant 7,-hich will lift the district's -.vater into the flume. Just ab:)ve the outlet of the fluinc into Eucalyptus Reservoir, the La Mesa ditch takes jut and carries water t ) tho Murray Reservoir, a distance of abo\it three miles. Tho ditch is an unlined earth section f.>r most of its length but th3re is a 36-inch wood stave pipe for about 1250 feet near the upper end. The Eucalyptus and Gr issrnont reservoirs are small repulating reservoirs but the Murray Reservoir has a capacity of almost 6,000 acre-feet. This latter reservrir is Located on a branch of Alvarado Cany-'n, a tributary of the San Diego River bolr.7 Mission G^rge, and abotit 3g- miles above the canym's mouth. It is firmed by a c :ncrete multiple arch dam v;ith 27 arches, each v/ith a 30-foot span. The maximum heierht cf the dam is about 110 feet. The spillway is of the syphon type and is 1. cited in the right end of the dam. The El Capitcn rescr/ ^ir is located m the main river end runs short iistances up the South Fork and Ch^colote Crook. Its storoge capacity is L16,900 acre-feet. Th., dam is a combine ti-^^n earth fill-r.^ck embankment struc- :ure with its crest at elevation 770 feet, U. S. Geological Survey datum. It -s about 1200 feet l.np, 217 feet high above stream bod, and 1240 feet thick at -he base. The spillway is of the side channel type and is located around the ■ight end of the dam. A somewhit detailed dcscripti :-n cf the dom and reservoir -159- is given l-'.tcr in this chapter undor "Conservrition Rescrv.iirs". The Government Dyke, near the lower end of the San Diepo River, runs fr.m the srjth end of the I.'":>rcna Boulovnrd Bridge at Old TT/n westerly to high gr und near the intersecti^ of Ingraham Street '.nd Point Loma Boulevard. It was originally constructed by the United States government in 1877 for the purpose if diverting the flo\7 of the river, v7hich entered San Diego Bay, into Mission Bay. The government's interest in this change 77as the protection of the navigable San Diego Bay f r jui filling by debris brought dovn by the river. T; insure m.re adequately the permanent diversion of the river and to protect lands s.Mith cf the dyke and extensive improvements -n these lands, the govern- ment raised the dyke in 1917 to an elevati.-n three feet above the high water line of the flood of 1916. The dyke ".vas again raised and strengthened, by having the cross-section increased and some rock revetment placed on the irater side slope, in 1933. The principal foregoing described existing vrorks on the San Diego River are sh r.vn on Plate XVII, "Location Map of Devel :pi!x;nt cf San Diogo River". A profile cf the development of the river is shT.m on Plate XVIII, "Profile of Development on San Diego River". The map on Plate XVII shov;s the relative sizes and locations of the votKs, and the profile on Plate XVIII shovs their relative elevations. On b rth the map and profile, the existing works are sh -vrn in solid black. Cr^r.plete Development for Conservation and Flo^^d Control . In the further development of the San Diego River, it is desirable to construct works which v/ill conserve run-off from the stream nov; wasting into the ocean, and t > pr->tect Lmds adjacent to the river from d.omage from flood overflow. It is believed that the best method v^f c.inscrving the wasted water v/ill be to construct additi :n;l roscrv ;irs on the main stream and San Vicente -160- -ly PLATE XVII PLATE XSm ainiep SOSTl Us^i ui uojteAaig o o o in o o o o o o m o o o o o o h- z UJ 2 Q. tr O UJ _l > LJ q: > UJ O Q Ji- O O QJ L- Q O m Z _j < Li- C/7 O OC a. o to ID in ^X>g^ 1201SSlJ/\[ ^DdOQ OlJlOVff \ o o o m o o o o o o n o o o o o o uun^ep-^-Q's-n 'psj ui uoi;eAa|3 Creek t; st jrc -.Titer during pori'.ids when there is mere runoff thin can be used, ani to held it f .t relcise during periods of lo:- runoff. This uill result in the holding of some vatcr in storage f jr sevcr-.il ycors in order to equalize the supply in net and dry pcri-xls. The protectim of the lands .idjc-cent to the river channel from flood overflow miy be accomplished either by the construction of levees to confine flo.;^. flow to a chf:nncl reserved for this purpose, by reducing the floo.'. fLcT? by storage in reserv lirs, or by -j combinnti Jti of both methods. Sites f )r additional reserv. irs in the San Die go River Basin are shown en Plate XVII by areas shade.1 with black and white bars. They are the San Vicente site on San Vicente Creak and the Mission Gorge No. 2 site on the main river. The reliti.ns of the vjlevations of these t-v- rcserv^^irs to each other and tz the existing reserv :iirs )n the stream are sh-i/V/n by the profile on Plate X'v'III. As an alternate to the Mission G-^rge No. 2 dam, one could be built at a site about 1-3/4 miles further dorn stream at what is knorrn as the Mission G:rge N:. 3 site, sh"^wn on both the map and profile. A '"iscussirm and compari- son of these tTvo sites is given in a following portion of this chapter. The Mission Gorge sites IJ n 2 and N.'. 3 are the local designations of two dam and reservoir sites locitcd in I/Iission G-rgo of the San Diego Eiver. Dam site No. 2 is located near the upper end of the gorge, ;Thile dam site No. 3 is located near t ho loTver end.. The f 1 ov lines of all sizes of reservoirs considered for both sites cxtcn'. above Mission Gorge into the upper San Diego Eiver Valley. The old lassicn Dam c instructed by the Spanish missionaries in the early part of the nineteenth century, practically all of vhich is still standing, is located at the extreme upper end of the gorge about one quarter of a mile east of the boundary line between Ex Mission San Diego and El Cajon grants. The tern I.lission Gorge N •. 1 d-ja has apparently been reserved for the -151- original rlim, tho first c instructed in C-lif:rni:^ after the coining of the vjhitc r-iGo. Alth-'Ugh the El Capitin, Sm Vicente and Mission Gorge reservoirs could be used f^-r flood cmtrcl, or far fl'.--.d control md c^nservati ".n cxibined, it h?,s been f 5und tk^it unless sp-ice for flood control is provided in addition to that required f^r c :nserviti )n, the v-ilue for tho latter purpose is decreased. It is believed that th. greatest benefit fr^-^n the reservoirs uill come from their use f'^r cjnsorvatiai as thsir primary function an^ this policy has been ad ptcl in tho stuUcs fcr required reservoir capacity in this investigation. It is shown hereinafter that a'lUti'ai 1 str^rago space f .r flood control could be provided in the Ivlission Gorge No. 2 reservoir v/ithout interference rith its value for conservati :n. The flDod control works m the river which have been investigated ore the rescrv-irs and leveed channels in the Mission Bay area and Mission Valley. A consi-'.er-jble logree of rf the reservoirs for c .'nservaticn -done an', further reduction could be accom- plished by the use if the Mission Gorge No. 2 reservoir for this piarpose, as one of its fixncti^ns, in •.• VUtion to its use prinarily for conservati -^n. The reductions in fljor. fl;'.7 '.ue t^ reservoir )perati ji would greatly benefit the lan^'.s in Mission Valley and the Mission Bay area but for the full protection of these areas, leveed channels are required. The channel dcsirned for the Mission Bay area TOuld be 650 foot t- 1000 feet vi^'e and extend vzesterly from Presidio Hill at Old T^"m. to Mission Bay at its outlet. Tho location of this channel is shrm on Plate X\^II. The channel through Mission Valley T7ould be ab:ut 600 feet -^ride and six miles long from Old T r.m to Alvarado Canyon. ■162- C Onserv:iti Ti Rcserv ;irs The gcncr-il method jf cstimiting the run-'^ffs fraa the S.'.n Diepc River Basin is describad in Chapter II. Somewhat detailed descriptions -^f the ;nQtho.'s of estimiting the run-Dffs at sevcr;jl points in the b:'sin, st the dnra sites on the niin river and San Vicente Creek, and from the areas lying between these dan sites, and a t';ble giving the estimated monthly run-offs at the dam sites and from the intermediate areas are given in Appendix A t ; this rcpr rt. Run-offs S5 estimated vjctg used in the studies to deterraine the pre bn bio yields of each reserv -'ir an", combinatim of reservoirs in the San Diego River Basin. Since the yiel' of the entire stream was to be estiniatcd, the full natural run-off was used for the stu'ios. As stated in Chapter II and Appendix A, run-offs f^T the four seasons 1883-1887 were estimated fr:3n rainfall reci.:rds and th^se f 'r the seasc.ns 1887-1898 f r -•;ri Cuyaiaaca and Sweetwiter reservoir operation records. After 1898, the run-offs were estinated from stream flow records taken at Mffcrent points in the basin by the water c x; panics and the U. S. Geological Survey. Next to the water supply, probably the ij:st iiiipurtant itei;^ in a study of the c 'nservati:!! and utllizati m. .;f the water av lilr.ble froio the Sm Diego River Basin is the evop jroti .n fri.i.j the rescrv^ irs v.-hich is rcl- tivcly 1 :irge in amount. Data on this subject were .^ibtained f r '-n oil sources available an' are suiimarizcd in Table 32 which sh"i;s the i.iean seasonal gross depths of ev^-pora- tion from pans located at a number )f 'l:jdLS in San Diego C .unty. D'lta in this t-'.blo in^.icate thit the depth of evapirati.Ti increases as the distance from the coast increases and also, t: s)i:.e extent, vd th increose in elevation. This is probably duo t. the fact that the Pacific Ocean has a uod.erating effect on the climate along the c xist by decreasing summer temperatures and increasing the humidity. As the distance f r Xi the coast increases, suramer temperatures become -163- I o en 1 y^ CM •^r* f<1 O « w t^ ^ s ^ o M H ^ O CO CO o « CO 0} •H O +^ n ID CO a o (U O rH o Q iVh •M +i CO 4-3 (U • CO a • • C3 • • •• a o • • c • • • • • • I • • • • 1 i • • • (0 • •• :3 a^ P^ ^ Oi (1< O ^1 a, Oi ^ A< Ph o u ;3 g, ^ CiC 00 ^ •rH bO ^ t)0 •iH •H (D ■rt •rt fl ■•-1 •H CO •rH •H c +» -p tg +3 +> tH •p 4J o -p +3 •rH CO CO iH cd CO CO CO rH CO CO o o n o o C o O piH o o d rH <-i rH •-i CO ■-i iH rH r-^ 00 i^ t^ a ;0 t o > p o o o M >, •rH o o o M >> -H fcO ^^ -P C5 CD fn 5j0 CD 50 o o u 33 0) -P rH +"> 0) 0) 0) r-A •P ■r-l •H o rt M to •rH •H •H c: rH CO Q o o 2 Cd •r-t o Q « o cd •H a +» ;q > n s > Q C (3 •ri fH 0) § c! s © (0 nJ Pi (U r-q tu) P! CO CO 1-1 !:? S CO CO p< > C O CO CO CO c o ■H o •k ■i-t •rH •• •rH -rH CO tD 0) CO M >i >> cq p^ ^ •rH >> >. >, s •H -p -p tj M +J H^ -p -O fn ■H •rH • a cd ir; fn •rH ■rH •rH Cd C Fh o CJ 1-3 hj ^ Cd !— 1 o CJ o .-1 cd IH CO CO en to CT1 CO CO o o o o o CJ LO o C\i o o o o o o to o o o to o u •H CO > •rH (=! cd Oh C7^ cu rH :H rH rH O 00 C\2 CM I I CM O rH CM cn o CO lO to CO CM CM ■— I to in rH CD Oi CO to in VD to in CM CD in CM 00 in CO CM >> >5 ^H CO ^0 a) •p -p -p o o g ^H u •p CD (0 4) a, (1) b P4 ? r-1 P UJ CO fH Fh -3 •P CO -P cd e (D c! h(1 Pi a) tJ Fh Pi o CO o HH m S CM O o O CO CM to I I CM r^ •-t CM in IS CM -164- tl-J-I grextcT, the huTiility decreases, ancl apparently the r .to of evap..roticn in- creases. Rescrv irs nc-;r the- crest jf tho aonntain rungc, such !.s Morena ind Cuyaitiaca, arc ^ore expcsccl t: tho dry h^t -.vinls fraa the -desert which .ilso tend t^' iacreasc tho rite :f ev-ip-rjtion. In estinating the evjiporaticm Ijsscs frjra the reservoirs in the yield stU''ies :f the Sm Diego Riv&r Basin, C'^nsi Aer-.ti n vras given t: the location one. olev-iti:n of o-ch reservoir. Fr -m the dit.i given in Tr-blo 32, and with the f^recoing c :nsi '.^.rati n, it "as estinitcd thit the rxan soas-n-al gross evap-^ration frxi the SI Capiton and San Vicente rescrv irs v.ould be 63 inches and that from the Mission GvTge rescrv .irs -.voizld be 60 inches. In studying the Cuyonaca reservoir, the actual measured depths ^f evopcnti-'n •i'jere used during the peri x\s of rec :.rd sh :-m in Tibbie 32 and f rr other seasons a depth of 72 inches -.las used. The gr ss depth of evapornti .m was distributed anang the months of the seasm by the percentages deterinined fron the average monthly amcunts during the periods of pan records. The " istributi -ti for Cuyanaca ~as dcterxuined frxi its e:7n rec rds. The distributi n f ;r El Capitan, San Vicente and the Mission Gorge reservi;irs w"as assumed the sauc as th^^t obtained fron evsp.ratim pan rec, rds for Ivfurray Ecserv-ir. Tho u^nthly gross depths of evaperatiTx f r Si tho El Capitan, San Vicente ani Ivlission Gorge reservoirs, and fron the Cuya:nica Reservoir for tho period prior to pun records and during the period ,f :aissing rec-rds, arc given in Table 33. The net m nthly depth of evaporation f r t2 each rcserv:ir -^ras estiiiated by deducting froii the rross depth 1 :{ of evaporation, tl^ o estir.nted Vopth f rainfall on the reservoir during the I mrnth. These net depths for the period 1894-1933 ore given in Table A-2 in Appendix A. Th3 t;t?l m-^nthly evaporation loss fron C'Ch reservoir was j obtained by xailtiplying the mean water surface during the ir.onth by the estinated ' net depth of evaporation for that lacnth. The losses so estii-^ted for one ncthod i of operating the reserve irs are given in Table A-4 m Appendix A. -165- l^SM £^_SiP_3J:'igo_River_With Surface Reservoirs - The longest peri^xl between 1883 anc'. 1933 in .vhich the- run-off of the San Diego River uas below mrml nas the nine consecutive sense ns 1895-96 to 1903-04, inclusive. In these seasons, the average seasaial run-off Tias only about 15 per cent of the average seascnal for the p&riol 1887-1933. In the season 1894-95 just preceding this dry period, ho-ever, the run-.~ff was about 3.5 tines the noroal. In all stu'Ucs of yield of the river, therefore, the seascns 1895-96 to 1903-04, inclusive, are con- sidered the critical period which detcrininos the "safe yield" of the streaxa. The "safe yield" of the entire streaia, of any individual reserve ir, or of any combination of roscrv:irs, therefore, as hereinafter estiDated, is the seasonal draft T7hich coul3. have been obtained, -.Tith^ut deficiency, in the period 1883- 1933, and vjhich prc-;bably c uld be obtained in all future seasons. In EBking the stu-'.ies if the safe yield of the San Diego River Basin, it was assumed that 5,000 acre-feet of water would be used every seas'on for irrigation and that the yield above this anount would be used for municipal supply. The monthly distributi :)n of each ^f these supplies is sh'wn in Table 33. Furthermore, in making tho studies, it was assumed that the reserviirs would be onpty at the beginning jf the seasm 1883-84. Also, due to the fact thot estimates of run-off s frx- 1883-84 to 1897-98 were made from rainfall records and from Cuyamaca and Sweetwater reservoir records, and that there may be s x.e err.r in their amounts, a miniraim of 20 per cent of the total estimated run-off into the reserv :irs used in each study during the pcfrioc": 1887 to 1895 was allof:ed to waste. This alljwance was aide s^ that even if the estimates of run- off were high, there woull be reasonable certainty that all of the rcser- v-irs wouli be lUll at the beginning of the critical period starting in 1895. In one study of the yieli from the coordinated operation of the Cuyamaca and El Capitan reservoirs, the reservr.irs were operated in accordance -166- h3 to M O o t-H o CO p to fl •M o > 0) 05 a> m en o u o o c: > o u >r-l 0) CO ro to O) C to o d > to cS « +j •H 4) ft -P ci3 a o r-l -H ID CO CD -r-t P >s to 6 PI to o d en CO in CD to CD <0 C\J •o If} en O CO to o to CO en o c\j OJ o 00 w n-l •^ eo irt CM "-J< C\i c^ CD o >* lO to 00 ^O CVJ • • • • • • • • • • >* ^f m c~ CO t^ s> CO CO in to CM si d ^H c5 -P V o P-( Vh -p o CO ■p o ft fl P ft ft :i m o •l-t in 00 to O in CO to cn CO CM CM cn to CM o C\i o o CO CO CM to CO cn in ^ r- ^D CD CO in o CO CO CT> o CO to in rH CO •;}< CO ^ CM CM e e in 'i' CM O to o 1-1 1-1 cn to CM "* ■P » 0) 4J in o o cn CM ■* CM ^ d rf >> u -I o o -167- ^ ■p to I ft to l'. u M h 0) o -'€> J3 ^ O fi S O U) 0) -♦> > o o o 1) •o a p o o o o o o o ^o o o o o o o CO o o o o o o CJ o o o o o o o c-1 -p o Eh - 1 % ' * * ■•r * • • t i- ... V. with an ngrcemont entered into by the City of San Diego anrl the La Mesa, Lemnn Grove, ani Spring Valley Irrigation District, an-^. relcises for municipal and irriga-fcion supply xiere made in accordance v/ith this agreement. In this stuly, the district was all.tted all of the •sater originating above Cuyainaca Reservoir anc. all flows up to a total of 27 second-feet of the \7aters originating below Cuyainaca Reservoir and ab jvo the Diverting Dam on the San Diego River and in the South Fork above the diversion of the district's fluine. The City of San Diego was allotted all of the '.vater originating bel.->w the South Fork and the remainder of all other -.VAters .-'riginating below the Cuyaraica Eeservjir, after the deduction of the 27 sec jn^^.-f eet allotted to the district. Of the storage in the El Capitan Reservoir, 10,000 acre-feet was allotted to the district and 105,872 acre-feet to the City of San Diego. The evaporation losses fron tho El Capitan Reservoir were divir.ed among the two parties in proporti 2n to tho onount of 7;ater each h;jd in storage at the be- ginning of each month. Cuyamaca Reservoir ',;as operated for the benefit of the district. The inflow into the reservoir was stored in the reservoir until the first of May and then released to El Capitan Reservoir until, if possible, the 10,000 acre- feet of storage allotted to the district -,7as reached. The agreenent between the Sity of San Diego anr. the district pciriits the (^strict to store water in El Capitan Keserv-ir in excess of 10,000 acre-feet temporarily between May 1 and October 31 of any season. Tho temporary storage rras net utilized in this stuiy because it ^as found that the use of such tcinporary storage resulted in a portion of the waters of the San Diego River allotted to the district being lest to the City of San Diego in the event cf a wi.t season following the season during which the te;nporary st 3rape had been utilized. If the district had 10,000 acr^-feot in storage in El Capitan Reservoir on Ktay 1, the water in -168- CuyaiBuca Reservoir was retained there until the next season. In this and succeeding stuc'.ies, all releases from Cuyaiiiaca Reservoir wore assumed to be subject to losses 3f 5 per cent. While under present methods of operation the losses frcra releases fvxi Guyamaca Reservoir are much greater, it 7/as felt that the iir;thod of release proposed in these studies would result in much sra-iller losses. The attempted draft for the district of 5,000 acre- feet per season resulted in a deficiency of 2,148 acre-feet in 1900 and a deficiency of 2026 acre-feet in the u inter cf 1904-05 or a total deficiency during the critical period 1895-1905 of 4,174 acre-feet. The supplementary supply uhich may be obtained frira underground basins below El Capitan Reservoir was not considered In this study. The draft Jf 9,000 acre-feet per season for the City of San DiegD r7as obtained throughout the critical period and 2,330 acre-feet remained in storage in El Capitan Reservoir on February 1, 1905. In order to determine r.'h ether a safe yield of 14,000 acre- feet per year could be obtained from the coordinated operation of the Guyamaca .and El Capitan reservoirs, another stu^'.y was male in "hich tiiere "./as no division of v/ater, draft or storage space between the City of San Diegc anf. the La Mesa, Lencn Grove and Spring Valley Irrigation District. This study "was made on a seasonal basis over the critical period 1895 to 1905. In it, infloT; to Guyamaca Reservoir ras stored in that reservoir until May 1st of each season, and then released as rapidly as p-. ssiblo to El Capitan Reservoir, if storage was avail- able or as soon as storage became available.- This resulted in a mnre efficient operation of Cuyaiaaca Reservoir through the reduction of evaporation losses, and a draft of 14,000 acre- feet per season, TTithout deficiency, was obtained, with 2,469 acro-feot remaining in storage in El Capitan Reservoir on February 1st, 1905. This draft is that sh :wn in the first line of Table 35 and is -169- believed to bo the safe yielrl of tho basin under present conditions, that is, with Cuy^uiacn ani El Capit-in reservDirs in operation. Studies were also ra-ide to estiiaate the safe yields of the Guyaranci and El Capitan resarv ?irs operated coord inately with tho San Vicente, I.lission Gorge No. 2, or Mission Gorge No. 3 reservoirs, respectively. The studios wore made T;ith four cip-icities of San Vicente reservoir, three capacities of Mission Gorge No. 2 reservoir, and tlireo capacities of Mission Gorge No. 3 reservoir. In all of these stui".ies, the Cuyainaca and El Capitr\n reservoirs r/ore operated as described in the last foregoing paragraph. A seasonal draft of 5,000 acre- feet for irrigation was furnished at all times. TThen San Vicente reservoir was included with Suyamaca and SI Gapitan reservoir in the study, the irrigation draft was obtained from the tvvo latter reservoirs as long as possible and. then fron. San Vicente. When iviission Gorge reservoir xvas used v7ith Cuyaraaca and El Capitan reservoirs, all of tho irrigatitm draft -ras taken fran the latter re- servoirs. The order in which water was dra".7n froin the reserv:)irs for ether uses with San Vicente in operati m was Cuyair^aca, El Capitan and San Vicente. With cither Mission Gorge reserv )ir in operation, the order ".vas Cuyaaaca, Mission Gorge an?. Zl Gapitan. This notho;'. of operation reduced evaporation losses to a miniiuuci by retaining the water longest in the reservoirs v.'ith the smallest evapor"ti?n losses, thereby increasing the total safe yield. The safe yields so estimated are given in Table 35 in sections 2, 3 and 4, re- spectively. The table also gives the additional safe yields due to the operation of the San Vicente, Mission Gorge N5. 2, or Mission Gorge No. 3 reservoir, respectively, with tho Guyamaca and El Capitan reservoirs. This additi;nal yieli is the difference between the total yielJ. and the 14,000 acre-feet fron Guyamaca and El Capitan reserv virs operated as previously de- scribed. -170- EstiLiatcs of the safe yield of the San Diego Kivor Basin nhove Mission Gorge T;7ere made by utilizing sufficient reservoir space to cmserve practically all of the run-off froiii ab^vo that point. In these stu--.ies, as previously stat- ed, ab.ut 20 per cent of the t..'t -1 run-5ff ^urinp the period 1887 to 1895 T;as Gll'3ncd t: -Taste so as to bo reasonably sure that all reservoirs would have been full at the beginning of the critical peri'X). 1895 to 1905. r7ith this assunptim, it 7;as foun-i that 130,000 icrc-foot f storage in San Vioonte reservoir -,/as the maxiiauni that coull be utilized to control that stream and that 57,600 acre- feet at Mission G 'rgc, in addition to tl:ie storage in Guyaf.iaca and El Capitan reser- voirs as now constructed vias all that could be utilized en the raain river. It 7?ouli be possible of c-urse to store less ':7ater in San Vicente reservoir and nore in the Missinn Gorge rosei*voir, holding the total to abr-ut 188,000 acre- feet. It vjas founl, ho-.7ovcr, that this t; xilr. result in a decreased yield duo to increased eviporati m losses. The S-'in Vicente reservoir site lies in a coEparatively narror; canyon, rhereas the greater pert of the Mission Gorge site is of the valley type. For equal capacities, therefore, the San Vicente reservoir 77ould have sraller surface areas and correspondingly shriller evapora- tion losses. Als.o, on account of the character of reservoir sites, the evapora- tion losses fr or_ the Son Vicente reservoir yould be less than from the El Capitan reserv.ir. In the stu lies of the coordinated operation of the Cuyainaca, El Capitan, San Vicente and Missi -n G.rge roscrv ,'irs the assumptions as to draft vrere nuch the saine as for the operation of either San Vicente or Mission Gorge roscrv ir, alone, v,-! th Cuyaraca and El Capitan reservoirs. The inflov; to Cuyanoca Reser- voir was stored in that reservoir until Ivlay 1st cf each season and then released aa rapidly as possible to rofill El Capitan Reservoir or, if no space was available in that reservoir, as fast as storage became available. A seasonal -171- -"'.raft of 5,000 acre-feet for irrigation was fiirnishod at all tines. Water f ;r this supply was obtained fron 31 Capitan Rcsonroir as long as water ras avail- able from it an.-! then from San Vicente reservoir. No water for this purpose was drawn fron Missi.-)n Gorge reservoir. Additional drafts for nunicipal supply were drawn fr-jn Mission Gorge and El Capitan reservoirs, in order, until each was e.npty, and then the draft was taken from San Vicente reservoir. This nethod of draft, for the reasons previously given, would reduce evaporation losses to a niniinua by retaining water longest in the reservoirs with the smallest evapo- ration losses. Since it was found that decreasing the storage capacity of San Vicente reservoir to less than 130,000 acre-feet and increasing the capacity of Mission G-orge reservoir to ni:.re th;.n 57,600 acre-feet, keeping the total of the con- bined storage capacities at ab ^ut 188,000 acre-feet, would result in a decreased yield, studies were made to deteinine the effect of increasing the size of San Vicente reservoir to inore than 130,000 acre-feet and decreasing the size of Mission Gorge reservoir. In these stu>.lies, Ifission Gorge N.. 2 reservoir was used. The method of operation was that described in the last preceding para- graph. The use of San Vicente Eeservoir to store vvater in excess of 130,000 acre-feet would be possible through the transfer of water to it frco El Capitan Reservoir, thereby preventing it frcr; spilling past that reservoir to Mission Gorge reservoir. The transfer could be made without expenditure for additional works by using the pipe lines frxi these reservoirs v;hich would be installed to transport the rnunicipal supply. These lines could be connected near Lakeside and the transfer acccniplished by gravity flor: when there was sufficient differ- ence in head between the -T^ater surfaces in the reservoirs. The transfer would be cade at such tiaes as the f\ill nunicipal s-apply draft was being taken from Mission Gcreo reservoir or vihen the pipe lines were n^t operating to full -172- capacity for this supply. The estimated s-^fe yields which could be obtained fron the coordinated operntiai of Cuyamaca, El Capitan, Sin Vicente and Mission Gorge No. 2 reservoirs are shr^m in Section 5 of Table 35. This table also shows the increase in yield vrhich could be obtained by increasing the capacity of San Vicente reservoir and decreasing that of Mission Gorge No. 2 reservoir. This effect is also sho^m graphically by the curves ^n Plate XIX, "Additional Safe Yields fron San Vicente and lAission Gorge No. 2 Reservoirs Operated Coordinately with Cuyanaca and El Capitan Peaorvoirs." The yields shown in the first three lines of Secti u 1/3 f\J (U ro r « u o >5 -f- d o Cl- o in o C) m lO 57,600 29,200 Additional safe yield in acre-feet per year I Mission Gorge No. 2 - 29,200 acre-fee+V San Vicente - 174,500 acr e-feetJ 16 I 18 Additional safe yield in million gallons per day 130,000- 158,400- +- L H- L. I OJ 0) lO u (D a. c (0 ro O lO ADDITIONAL SAFE YIELDS FROM SAN VICENTE AND MISSION GORGE N2 2 RESERVOIRS OPERATED COORDINATELY WITH CUYAMACA AND EL CAPITAN RESERVOIRS 174,500 icre-feot in San Viccnto reservoir ancl 2^,200 acre-feot in Mission Gorge No. 2 reserv-ir, f r the period 1894, the yoar preceding the beginning of the critical period, through the season 1932-33 is given in Appendix A of this report. A sunmiry of the study is given in Table 34, and n graphical presenta- tion of the summary is shovm on Plate XX, "Combined Operation of Reservoirs on San Diego River". The yields are also shorm in the last line of Secti-.n 5 of Table 35. As shcma by Table 35, the increase in capacity of San Vicente reser- voir from 130,000 acre-feot to 174,500 acre-feet to care for the transfer of water to it frora the San Diego River for storage, would result in an increase in the safe yield of 2,900 acre-feet per year, )r 9.8 per cent of thx) total yield and 18.6 per cent of the aiditional yield. In order to determine the effect on the yield of the San Diego River of using the Mission Gorge No. 3 reservoir site instead of Mission Gorge No, 2 site, a study the same as that described in the foregoing paragraph, and shown in Appendix A, V7as irude, using the No. 3 site instead of the No. 2 site. The capacity of the No. 3 site was taken at 29,200 acrtj-feet, the same as that for the No. 2 site in the ether stuiy. The safe yields estimated from this study are sh^wn in Section 6 of Table 35. A cx.parison of these yields with those given in the last line of Section 5 of the same table shows that the use of Mission Gorge Nt. 3 site instead of Mission Gorge No. 2 site irould increase the yield 300 acre-feet per year, or about one per cent. A sumiTjary of the safe yields estimated by all of the foregoing de- scribed studies is given in Table 35. In the foregoing studies, no account has Ijcen taken of the effect of reduction of reserv .lir capacity by the deposition cf silt or debris brought down by the water. From information obtained from constructed reservoirs in San Diego County, it is estimated that the amount of material deposited in the -174- TABLE 3U SU1.MARY OF STUDY TO ESTIf/JlTE SAFE YIELD OF SAN DIEGO RIVER WITH COORDIIIATED OPERATION OF CUYAl-lACA, EL CAFITAN, SAN VICENTE AND MISSION GORGE NO. 2 RESERVOIRS Ouyamaca Reservoir 11,600 acre-feet El Capitan Reservoir 116,900 acre-feet San Vicente Reservoir 17U,5C0 acre-feet Mission Gorge No. 2 Reservoir 29,200 acre-fe et Total Storage Capacity 332,200 acre-fe et (1)F1cw into: Water in Evaporation : Draft from : Flow over spill- Season : reservoirs, : storage : from : reservoirs, : way at Mission in acre-feet: October 1st ,: reservoirs, : in acre-feet: Gorge No. 2 , in acre-feet: in acre-feet: in acre-feet 189^95 : 166,978: 236,593: 14,949: 32,500: 54 ,393 1895-96 : U,89^: 301,729: I3.76O: 32,500: 1896-97 : 20,833- 260,363: 9,293: 32 .500: 1897-98 : 2,^33: 239.403: 10,375: 32 ,500: 1898-99 : 1,SU9- 198,961: 8,487 32 ,500: 1899-oc 9^5: 159.823: 5.971 32 ,500: 1900-01 8,56U: 122,297: 4,319 32 ,500: 1901-02 . 7,456- 94,o42 4,264 32 .500: 1902-03 15 .257 64.734: 3.842 32,500- 1903- cU 1,290 43,649 2,757 32,500 1901+-05 50 ,015 9,682 2,784 32,500 1905-06 110,93^ (2) 23i888 5.856 32 ,500 1906-07 11 Ms 96 ,466 7,711 32 ,500 1907-08 24,234 127,703 7.396 32,500 190s- 09 57,739 112 ,OUl 7.226 32,500 1909-10 33 .481 130,054 7.771 32,500 : 1910-11 19,602 123,264 7.340 32,500 1911-12 23,069 103 ,026 5.682 : 32,50c 1912-13 10,472 87.913 4,825 : 32,500 191>1U 25 ,496 61 ,06c : 4,238 32,500 : 191^15 107,827 49,818 6,473 : 32,500 : 1915-16 351 ,231: 118,672 13.875 32,500 : 145,160 1916-17 4c ,4i3 278,359 15.745 : 32 .500 653 1917-18 30,826 : 269 .874 : 14,633 : 32,500 : 1918-19 10,655 253,567 11 ,o46 : 32,500 : 1919-20 : 42 ,209 : 220,676 10,324 : 32,500 : 1920-21 : 6 ,985 : 220,061 : 10,725 : 32 ,500 : 1921-22 : 200,998 : 183,821 l4,872 : 32 ,500 : 40 ,077 1922-23 : 22 ,098 : 297,370 16,070 : 32 ,500 : 1923-2U : 8,659 : 270,898 : 12,459 32 ,500 : : I92U-25 : S,704 : 234,598 : 10,488 : 32,500 : : 1925-26 : 35,873 : 200,314 : 8,392 : 32,500 : : 1926-27 : 184,421 : 195 ,295 13.691 : 32,500 : 25,045 : 1927-28 : 11,798 : 308 ,480 : 14,743 : 32.500 : : 1928-29 : 15 ,030 : 273,035 : 11 ,485 : 32 ,500 : : 1929-30 : 19 ,036 : 244 ,080 9.897 : 32,500 : : 193c- 31 : 9,704 : 220,719 : 9.452 : 32 ,500 : : 1931-32 : 101 ,724 1^8,471 : 11,437 : 32 ,500 : : 1932-33 : 26,674 : 246 ,258 10,867 : 32,500 : : Averages : 48 ,509 : 9,372 : 32,500 : 6,8C4 (1) Flow i nto reservoirs consists cf flow into Cuyamaca, El Cap itan, San Vicente and Mi ssicn Gorge No, 2 reservoirs less transmission losses between Cuyamaca and El Capitan reservoirs. (2) On Feb . 1, 1905, San Vicente Reservoir had 525 acre-feet of water in storage This q iiantity was d isregarded an d the reserve ir assumed to be empty at that time. -175- PLATE XX CC6l-eC6l 0e6l-626l 0261-6161 0161-6061 0061-6661 S69l-t'6ei ;a8_^-ajDV -P • • • • •• .« • • •• « • •• .* •. *• • • t> .« *. « • •• •• • • • ■ •> •■ •• •# • • •• «• -P O O 6) ■■ — " ^4 o +3 x^ JJ ti O fO \n rjl ^ rH -# CO «J< 0) rH to «D CO CO CO to CM CD C8 rH *-( -P c: " CD •<* Oi ^J< CO <1< G> to c3> CO in C- rH 1 d w t4 >s . . • . • * . . « • . • . . . ^ ^ (d O o •rH O CO c^ o c\j •<# w CO in N •* in c\j CO in to to rH h CI rH .-1 T3 r-l rH rH r-{ r^ r-i r-i r-i 'd C J3 V ^ rH rH -P O -P a o o ri P •H a) " X. ' • • « • •• •« •• •• • • •• a • © t3 «% > CO o fl w ID o 4J» > — ' o CO r-t •rH Q't cO o o o o o o o o o o o o o o o CO -P ^ M <;h o 1 >5 CO ^ lO C cvj ev2 in CO o X3 ^ ij « § ID CO rH «* «3 w"-* in" to in tO •>a< in D- CD CD* -p tS ^ fn fn f-i r-{ r-i rH rH rH rH r^ CO rH -P /3 ■P ■H ft CO ^3 1 • a i* (h o ft O ® ** • • 4 • «• ♦• «■ •• « • .• •• in u ■s r-\ iV-< ^t 0) o» CO to CO Oi ^ rH -^ CD O Cv2 o O (i: • • • . . ... . . • • . • • • > 1^5 o a o d >> CO o c\3 in «o ■^ O IN in 5D CO in to i>- o» OJ u Vh ■H o CO r-< w w w w r-i f-i r-i r-i rH rH c\j c v< o o OD C- uO CO t> CO CO w o C-- CO to c: in CO M >^ 1 >1 ^ M .k •. #« M n •« «k ^ .k r-i ^ 'in O « 3 o <# w in CD o «D CC' 0> O Oi o Co" CtT rH CO* CM* Cd O Xi ^ h h H N C\3 CM CO <-{ r-\ r-i H rH N CM CM CO to CO r-i to o o c •xj rH T) o ■< ft d •H 00 CO 1 • • •• CO CO ft O 73 CO +J rH CO © in " to •h o . U M a -rH u o o o o § CO ^^ 1 & H O s ^H W Oi . " f^ -H i^ 'jj f- •rH . •* •k *> 3 !H -rH O H O a H o ^: o ^^ H o •r-i -P tr. •H O ■rM k=^ > U CM water, nto Reservoi the reserve voirs and th 0. • •• •• CO oj cj +^ •rH +3 M -rl © D ? 1 c! • o > 05 CN (O to c^ C!» en a; o f^ W fH o u o o u cj in (D CO in CM CM ^H -P CO V< i/ O O CO -^ o" o" CD* >* '*" •r-l e in d ^1 M W O CO lO t> o CO in o [> ?>> « © H M |L o c c ,-i .-{ ^ ,-\ r-i r-i ^ r-t rH c •* t> © « V ■£S 3 K -P ^ I> ^ ^ £ in c -P rH ^H -P A (D CO © (J © x; ft f» -p © a > w fH ■H .H <0 J3 5 •H P^ t;:: ^ rH -P J +3 H K CO -# in «o ^ Q ^ — . ^ . ^ .i CO • a • ■ •* ., rH CM -176- El Capitin, San Vicente and Mission Gorgo reservoirs niifht amount to about 340 acre-feet per year on the average. Most of this material would probably be caucl"'t in tho El Capitan and San Vicente reservoirs but some silt or debris would be picked up by spill from these reservoirs and by run-off originating beloTf them and carried into I^ission Gorge reservoir. Since it would be possible to transfer water from El Capitan reservoir to Sari Vicente reservoir for stor- age, any fill -^hich may occur in the former reservoir rmy be considered as occurring in the latter. It may be seen from tho last two lines of Section 5 of Table 35 that a decrease in the capacity of the San Vicente reservoir would result in a decrease in the safe yield of the four reservoirs operated coordinately. Decrease in the capacity of Mission Gorge reservoir would have the same effect. Therefore, to maintain the safe yields shown in Table 35 over a long period of years, the San Vicente reservoir should be constructed originally to a capacity sufficiently greater than those shown in Table 35 to store the amount of material which would reach it and the El Capitan reservoir in the same period of years, and the I;iission Gorge reservoir sho'old be given sufficient additional capacity to store the laaterial which would reach it. Use of Underground _PleseTVoirs for Seasonal_and_Cj^clic Storage - In the fore- going described studies, the ultimate conservation development of San Diego River waters contemplates the use of a 29,200 acre-foot reservoir with a dam in Mission Gorge to store the spill from the upstream reservoirs and the run- off from the areas below El Capitan and San Vicente reservoirs. There are in the upper San Diego River Valley and Mission Valley, however, underground basins of considerable capacity which, if properly charged and drained, might be used in -place of the Missict Gorge reservoir for the storage of a part of the run-off of the river and tributary streams. The subctitution cf the under- grouni reservoirs, if possible, would have several advantages. The chief of -177- these would be, of course, the saving of the cost of the Mission Gorge dam and reservoir lands. Another saving V7ould bo in surface reservoir evaporation losses if the underground basin woro so operated as to keep the water level below the roots of the brush and trees to prevent loss by surface evaporation and Vy transpiration. A study of these underground basins has recently been made by J. C. Kimble and the utilizalile storage capacity of the upper San Diogo River Busin was astimatei as 24,200 acre-feet and that of Ivlission Valley basin as 10,500 acre-feet. The upper San Diego River Valley basin extends from the Old Mission Dam to Cape Horn and includes the San Vicente sub-basin. However, the greatest depth of fill and more than sixty per cent of the total capacity in this upper basin occurs above Lakeside. Bettreen Mission Dam and Sycamore Canyon the shallow fill does not permit of an appreciable amount of storage. While the entire drainage basin area of 111 square miles above I.'ission Gorge and below San Vicente and El Capitan dam sites, as T;ell as the local side drainage below Mission Gorge, is tributary to the Mission Valley underground basin, only about one half of the 111 square miles is tributary to the upper underground basin, and that portion above Lakeside, having an estimated storage capacity of 15,440 acre-feet, has but 28 square miles of drainage basin tribu- tary to it. ^ith the completion of El Sapitan Reservoir and the construction of San Vicente reservoir, the basin Tvould be dependent upon the run-off from these 28 square miles and the infrequent spills from the reservoirs for re- charging. While the Mission Valley basin is located at the lo77er end of the San Diego River drainage basin, the comparatively small capacity of this basin would be insufficient to conserve the run-off tributary to it if no reservoir were constructed at Mission Gorge. The spills from the upstream reservoirs -178- v;ould oocur during large storms at a time T/hen the local run-off v/ould probably be of greater magnitude than the absorptive capacities of the underground basins. The flood flows of the San Diego River are in general extremely flashy and of comparatively short duration, which would result in large surface outflows during the inajor floods and result in T7ater Tiasting into the octan. At present both basins are being utilized for irrigation supplies and by the City of San Diego for municipal supplies. The La Mesa, Lemon Grove and Spring Valley Irrigation District has v.ells and a pumping plant in the upper basin at El Monte for the exportation of water. The present installed capacity of pumping equipment in wells in the upper basin is probably greater than the safe yield from the undergroind basin after the construction of El Capitan and San Vicente reservoirs. The quality of vrater for domestic use in parts of the Llission Valley basin is inferior to that from the upper basin, but it is probable that if greater use were made of this basin by the exportation of water, the replenish- ment -;vith surface waters v/ould improve the quality. In view of the location of the upper underground basin with respect to the drainage basin tri;:utary to Mission Gorge reservoir, the high rate of absorption necessary to store the flashy flood flows, the inability of the underground basins to catch any appreciable amount of the spill from the up- stream reservoirs, and the fact that only a very small part of the upper under- ground basin area would be flooded by a Mission Gorge reservoir of 29,200 acre- feet capacity, no safe yield studies or cost estimates have been made in this investigation of these underground basins, and they are not considered adequate to replace the Mission Gorge surface storage. Any yield from the Mission Valley underground basin derived from the local run-off and spills from the Missicn Gorge reservoir will be over and above -179- the safe yields shown for complote development by surface storage. Any yield derived from the upper San Diego River underground basin will loT?er the safe yield shown for complete development by surface storage but the aggregate sura of that secured from the underground basin and surface reservoirs will not be loss than the safe yield shown, and may be slightly greater. Cu^aina£a_R_es^rvo_ir - The Cuyamaca Reservoir is located on the headwaters of Boulder Creek, a tributary of the main San Diego River, in the Cuyamaca Grant on what would be the line between Twps. 13 and 14 S. , R. 4 E. , S.B.B. and M. if this lino T7ere extended into the grant. Its location is sho'.m on Plate XVII. The reservoir '.Tas constructed in 1887 and is nor; the property of the La Mesa, Lemon Grove and Spring Valley Irrigation District. Data on the elevations of water surfaces and the areas of the reservoir, depths of water, and capacities of the reservoir at these elevations, as obtained from the irrigation district, are given in Table 36. TABLE 36 AREAS AND CAPACITIES OF CIJYAI.IACA RESERVOIR : Depth of water Water surface Area of Capacity of : : at dam, elevation water surface. reservoir, { : in feet of reservoir, in feet, U.S.G.S. datum in acres in acre-feet ; : 10 4603 9 15 : 15 4608 150 350 : : 20 4613 354 1540 : : 25 4618 574 3790 : : 30 4623 776 7120 : : 35.4 4628.4 (1) 978 11,600 (2) : (1) Crest of spillway. {2) IvffeLxiraum storage capacity. -180- The dam for the reservoir is of the earth fill type cith a maximum height of 40 feet and a crest length of 665 feet. The top of the dam has a TTidth of ten feet and the approximate slopes of the faces are 1.7:1 upstream and 1^:1 doTvnstream. The upstream face is protected by a layer of rock rip rap. There are spillr.-ay channels at both ends of the dam. The channel at the left end is 47 feet "7ide and 5 feet deep belov; the crest of the dam. The channel at the right end is about 84 feet wide and 4.5 feet deep. Both channels have concrete sills but are not concrete lined throughout. The combined capacity of the channels is 3,800 second-feet. The outlet from the reservoir is a 3 foot by 4 foot masonry conduit under the central portion of the lam. TTater enters this c:nduit through a circular brick cutlet tourer having an insicle diameter of five feet, in which there are tv7c 3 foot by 4g foot wooden regulating gates 16 feet apart rith the I'Ower gate at the elevati:;n of the conduit. E1_C ap_i t_an_R£S£rv :_i r - The El Capitan Reservoir site is located in Sees. 14, 15, 21, ££, 27, 28 and 33, T. 14 S. , R. 2 E. , anf. Sees. 3, 4, 7, 8, 9, 10, 16 and 17, T. 15 S. , E. 2 5., S.B.5. and H. The iam site for the reservoir is located in the Ef of the NE^ of Scctiwn 7, T. 15 S. , E. 2 E. , about 7 miles easterly from Lakeside, The dam has recently been completed and the reservoir is storing the r^jn-off of the 1934-1935 season. The reservoir is the property of the City of San Diego and is to be used by the city and the La Mesa, Lemon Grove and Spring Valley Irrigation District. Data on the elevations of water surfaces and the areas of the reservoir, depths of water, an' capacities of the reservoir at these elevations, as obtained frcm the 3ity of San Diego, are given in Table 37. -181- TABLE 37 AREAS AND CLPACI'TIES OF EL CjIPIT.VN RESERVOIR Depth it :jater at dain, in feet 40 60 80 ICO 120 140 150 180 10 -^ 200 217 Water surface elevation of reservoir, in feet, U.S. G-S. datum 593 613 633 653 673 693 713 733 750 (1) 753 770 (£) ilrea of water surface, in aores 101 219 352 519 708 883 1,096 1,359 1,580 1,613 1,855 Capacity of reservoir, in acre-feet 1,500 4,700 10,400 19 , 100 31,400 47,300 67,100 91,600 116,900 (3) 121,300 150,800 (1) Crest f spillway. (2) Top of dam. (3) Laxiiraim st-^rago capacity. The El Capitan darn is a combination earth fill-rock cni ankment structure, with m:ist 3f the earth placed by the hydraulic mcth'>d. The top of the dam is at elevation 770 feet, U. S. Geological Survey datum, at rrhich olevatio.n the crest has a -^idth of 26 feet and a length (f about 1200 feet. The foundati -n is approximately 25 feet bcl:Tv; the "riginal stream bed level and the maximum height of the dam is ab^ut 242 feet above foundation. On the upstream face ;f the dam., the si opus gra'.ually change from 3:1 at the bottom tc 2:1 at the top. On the corAnstream side, the slopes change from 3:1 at the b:ttom t^ 1-3/4:1 at the tO'P. The maximum thickness of the dam at the base is ab -ut 1240 fset. The upstream ani do\.7istream toe secti-ns if the dam across the stream bed are composed cf rock dumped in place to fv-rra retaining dams for the hydraulic fill in the center. These fills extend to elevati'^ns of about 650 feet upstream and 620 feet downstream. Above these clevati-ns, the r.^ck -182- which forms the faces of the dam was also used during c instruction to retain the hydraulic fill. The central portion of the dam below elevation 718 feet is a hydraulically placed earth fill with a puddle core of fine impervious material approximately under the crest of the dam. Between elevations 718 and ^i52> feet, the earth sect! .n ?7as constructed ty compacting the material by rolling on the upstream and downstream sides and puddling the material in the core. Between elevation 753 feet and the crest of the dam, all of the earth section was com- pacted by rolling. Under the puddle cere, there is a concrete cutoff wall keyed into bed rock and extending about 20 feet into the earth fill. The spillway is ■.->f the sv'.q channel type and is located around the right end of the dam. The channel is mostly in rock or decomposed granite excavation and is concrete lined. It extends 1550 feet from a point about 500 feet upstream f r m the center line of the dam to a point about 400 feet below the d :'wnstrcam t-ie, from which point an unlined cut will carry the water to the natural channel of the river. The channel is 30 feet T;ide at the upstream end of the spillway crest, 215 feet 77ide opposite the downstream end of the crest, and 150 feet wide at the lutlet end. The spill\?ay crest is 510 feet long and is of the ogee overflow type, without gates or flashboards. Its top is at elevation 750 feet or 20 feet below the top of the dam. The estimated capacity of the spillway with a depth uf water of 12 feet on the crest is 7D,000 second- feet. Diversion of the stream flow during construction was made through a 25-foot diameter concrete lined tunnel under the left abutment of the dam. An additional concrete lining has been placed in this tunnel which will be used for the outlets fr:im the reserv .>ir. Two 42-inch and two 36-inch pipes have been laid through a concrete tunnel plug near the upstream end of the tunnel and will connect with the delivery line leading from the reservoir. Water will -183- enter these pipes from a circular concrete tower, with an inside diameter of 12 feet and a height of 210 feet, located alongside the diversion tunnel about 56 feet from the inlet portal and atout in line with the upstream toe of the dam. Flow into the tower is controlled by six 30-inch saucer valves in cast iron elbows and one 30-inch square slide gate, all manually-operated from the top of the tower. The saucer valve inlets are located at 25-foot differences in eleva- tion above the lo-,7est one at elevation 610 feet. The 30-inch square slide gate is at elevation 569 feet and is in an inlet from the side of the tunnel. The reservoir lands lie along the main San Diego River, its South Fork, and Chfcolate Greek. They are relatively flat next to these streams but extend up the steep slopes at the sides of the canyons. All of the lands have been or will be cleared of vegetation. San X^c,en^t£ Re^erv^ir - The San Vicente reservoir site is located on San Vicente Creek in Sections 17, 19, 20, 28, 29, 30 and 51, T. 14 S. , R. IE., and Sections 25 and 36, T. 14 S. , R. 1 W. , S.E.B. and I,'. The dam site is in the SW:^ of the NW^ of Sec. 31. The location of the reservoir site is shown on Plate XVII. A topographic survey of the reservoir site to elevation 650 feet U. S. Geological Survey datum, was made by the City of tian Diego in 1923, and a map was drawn from this survey at a scale of one inch equals 500 feet, 7,'ith a contour interval of 10 feet. The water surface areas of the reservoir as obtained from the City of San Diego, and the capacities of the reservoir computed from them are given in Table 38. -184- TABLE 38 AEEAS AND CAPACITIES OF SAJI VICENTE KESEF.VOIR : Depth of -.Tater : Water surface Area of ; Capacity of : : at dam, elevation water surface, : reservcir, : : in feet of reservoir, in feet. in acres in aore-feet : U.S.G.S. d'itum (1) : 84 540 400 11,300 : : 104 560 562 : 21,000 : 124 580 690 33,500 : 144 600 820 48,600 : : 164 620 936 66,300 : 184 640 992 85,600 : : 204 660 1,114 106,300 : : 224 680 1,238 129,900 : : 244 700 1,320 155,500 : 264 : 720 : 1,414 182 , 900 : 274 : 7?0 : 1,462 : 197,200 : (1) From City of San Diego. A survey of the dam site was also made by the City of San Diego in 1923. A topographic map drawn from this survey on a scale of one inch equals 100 feet TTith a contour interval of 10 foot v-is used in laying out and estimat- ing tho costs 3f d-iuas at this site. The geology of the dam site has been studied recently, in connection with the preparation of this report, by Chester Marliave. In this study, he ■^as ai;'^.ed by information obtained from six h:.les, rrith an aggregate depth of 221 feet, drilled in th^ stream channel, and f r :>m a tunnel excavated into the right abutment and another excavated into the left abutment. All of this exploratory work was done about 1926 by the City of San Diego. Further explora- tions of the dam site by tunnels and drilling sh'Juld be made before the final location for any dam at this site is selected. Sufficient funds for such ex- plorations are included in the items for engineering and contingencies in the following cost estimates for the dam. A descriptijn of the geology of the site, -185- I as taken from Chester Marli;ive's report is as follo',.'s: "The San Vioonte dam site is underlain by an olcl metamorphosed series of rJcks nhich is .ftnn sp ..kon of as tho crystalline cauplex. This term right- fully suggests a complex mixture of rocks of considoraMo age which under the heat and pressure jf mountain making movements, has fused these original rocks and rocrystallized them into n hard massive conglomeration in which much of the original segregation is lacking. Horever, tho structure of the criginal f'.rroa- ti ms often carried through into the metamorphosed rock and at the San Vicente dam site there is a splendi.^. example of it. The Peninsular Range of which this area is a part is composed for the ra^st part of igneous rocks of which granite predominates. "Some geologists who have studied the region in the scuthern part of the State believe that there is a possible fault running up the side of San Vicente Canyon and crossing into the hills about a half mile west of the proposed dam site. The location of this fault has been projected northwesterly and south- easterly from the dam site for about 15 miles in each direction. Observation of the topographic evidence along the eastern slope of tho canyon wall between the mouth of the canyon and Foster shows no evidence that the fault has been active in historic time. At any rate, the fault does not pass through the dam site and therefore is not of serious concern. "The rocks at the dam site are mostly granitic in character. They are hard, quite massive, have the usual fractured structure and are well exposed over most of the abutments as well as in the canyon bottom and on the higher slopes of the mountains. Interfused with the granite were some sediments in the form of sands, clay shales and possibly some volcanic ash. These sediments have for the most port been metamorphosed to hard silicified rocks but the original color and texture has been carried through the process and appears -186- VC-IV outstanding in certain exposures from the grnnitc. "Faulting is not evident -it the dam site. Some of the cross-fracturing has resulted in difforentiil ;n.)Veracnt v/horein these cracks are filled 77ith crushed material but their extent is not great. Sever'il of them Tiere follov;ed f:r over fifty feet in the draw upstream from the axis of the dan. These frac- tures sh.ul.I tifhtcn up a sh :rt listance f r :.m the surface. "The structure of the rocks at the d-jm site has a general direction running up and aovn the canyon nith an easterly dip between 60 and 80 degrees. This structure pertains to the sedimentary rocks T.'hich rccupy the stream bed and the easterly or left half of the dam site. A peculiar f e iture is that the adjoining granite seeus tc have a fracture system somewhat similar to that of the metomorphosed sediments, as uell as several others. Because the granite and ■ the sediments are fused together, it is difficult to draw a contact between then and often hard to distinguish the origin of the rock itself. Above the highway Ion the left si-.e of the dam site, the sedimentary rocks con be seen outcropping vith an overhang. This is due to the structure of the rocks 7/hich dip steeply into the hill r.ith some of the weaker members weathering away more readily than the more c-mpetont members. "The channel section of the dam site has a width of about 100 feet. This area represents the present sandy portif;n of the stream against which the talus slopes terminate, rising up gradually till the rock outcrops on the hill sides iire encountered. Six hcles were drilled in the stream channel about 19E6 by the City of San Diepo. According to the drill records, the sand in the channel is comparatively shallow, having a maximum depth of 15 feet. The lf dan.. On the right hand side of the -187- sandy portion of the channel there is a width of about 25 feet of loone rock before the bedrock is encountered on the right abutment. On the left side of the sandy portion of the channel section there is about 200 feet average width before rock exposures are encountered on the left abutment. The concrete high- way runs along this side and below the highway fill is the fill of the old county road. The fill material from these two roads has obscured the bedrock that might othcrv/ise appear along the bottom of the slope in the channel section. "The rock on the right abutment of the dam site, as disclosed by surface outcrops, is granite as far as can be ascertained. A tunnel v;hich had previous- ly been run into the hillside, at an elevation about 12 feet above the stream bed, passes through a belt of sediments for 45 feet and then encounters granite. The projection of the steep vertical contact between these two rocks was traced out on the surface, and it checked up with the surface outcrops as closely as could be expected. This contact seems to represent the western edge of the belt of sediments that underlie the dam site. Most of the surface exposures of this sedimentary rock are very hard, much like the granite, but in the tunnel some shale beds were encountered which v/ere not quite so hard but of satisfac- tory character for dam foundation. "In examining the right abutment, a small fissure in the hillside was discovered which was thought to bo a fault of recent activity, because of the open trench ivhich it exhibited continuously up the hill over the right end of the dam site. Upon investigation, the fissure or open fracture, which was several feet wide and as much as 10 feet deep in places, was found to be com- posed of a fine grained dike about t-rvo feet in width. This dark dike looks much like a sandstone or black shale bed but as near as could be ascertained, the rock on both sides of it is primarily a granite. The softness of this dike cause* it to -jeather more easily than the granite, thus forming the trench- -188- like opening over the hillside. "The rocks that come within the confines of the left abutment are the metamorphosed sedinicnts. A tunnel ■;;vhich had previously been run into the hill a short distance in elevation above the high77ay encounters sandstone rocks all of the V7ay. These rocks arc bluish in color and more or less fused into a crystalline rock like quartzite. A well exposed section of similar bedrock was found in the ravine on the downstream side of this abutment T^here the recent rains had washed the detrital material from the surface exposing the structure of the sediments. This exposed section was traced up the hillside beyond the crest elevation of the highest dam considered for this site, where the sedimenta- ry rocks finally gave way to granites. The granite which lies at these higher elevations seems to have encroached over upon the sediments in this area. The condition of the contact could not be obtained at this location but a few hun- dred feet upstream from the probable left end of the dam, the contact between the granite and the sediments was clearly observed and was found to be tightly healed together. In following down a ravine just upstream from the left end of the dam site, the sedimentary rocks were observed to bo hard, tight and of satisfactory quality almost as far doT.-n as the road where they disappeared under the alluvium." A gravity concrete or rock fill type of dam could be built at this site and both types have been considered and studied. As has been previously shown in the description of yield from the San Diego Kiver Basin, the San Vicente reservoir would be the last one drawn upon and water might remain in storage for a long period of years. It is, therefore, essential to reduce leakage losses from the reservoir to a minimum or the amounts of water so lost might decrease the safe yield of all the reservoirs a material amount. It is believed that seepage and leakage losses can be made much smaller with a gravity ccincrete dam -189- than '.7ith a rock fill lam anc". for this reason thf: former type v/as selected for this site. G:sts v.ith these types v;ore found to be approximately the same. Estimates have been ma'.e 5f the costs of reservoirs with gravity cc^n- crete daias 209, 234, 256 and 268 feet in height. In making these estimates, all cf the dams v/ere located v;ith the upstream face in the same positi )n in the can- yon. The dams would have a vertical upstream face and a downstream slope of 0.807:1 starting frim the upstream crest line of the non-overflow portions of the dam. The crests ^f the portions n-t occupied by the spillv/ay would be 10 feet Tide with an approximately vertieal face from the downstream crest line to an intersection with the sloping ".f.Tnstrcam face Df the dam. For all heights '-f dam, the spillway -/ould bo pla'*.ed in the crest of the dam uver the stream channel. It would be 300 feet in length and its crest wuuld be 10 feet below the tvps of the non-ovorflo"; secti ms of the dam. Uit h this length and depth • f spillway, tho estimated crest flo-.v from a flood which may occur once in 1000 years m the average would pass over the dam without overtopping the non- overflow portions. T7alls Vown the face of the dam from each end of the spillv;ay crest 7/ juld guide the water fr m it over a curved concrete bucket 145 feet in length, across the ly.7est part of the channel, at the toe of the dam. No gates or flashboards "ould be placed in the spillway and the normal maximum water surface would therefore be :it the elevation of the spillv;ay crest. The outlets from the roserv nr would consist of 30-inch steel pipes embedded in the concrete of the d^m at elevati.^n 480 feet, or ab-^nt 24 feet above the stream bed level. Two pipes would extend entirely through the d.-im an", connect with the delivery line leading from the reserv- ir. Fl-w through each pipe would be controlled by a slide valve located in a chamber inside of the d3m near the upstream face. Access to this chamber vjould be from the drainage and inspection gallery which would run through the dam. A third -190- 30- inch pipe to be used f'->r a sluicc-J-iy \h\ilc\ exten: thrugh the clam frcm the upstre-.m face and clischiirge into the spill;7-iy channel just ah ve the bucket. Fl -v; thr>ugh it rroull also be controlled by a sli'o vulve 1 c ted in the same chamber as the other valves. 7ater would enter the pipes thnugh a semicircular concrete t .^wcr 20 feet in xitsido diameter extending from the f:undati' n line to the t -.p 3f the dam. This tiAver i;7ould be located just tc the left of the left end of the spillway section <.f the dam . Water vjruld enter the tower thr>ugh five 30-inch circulor slii'e g'ltes operated from a gate house at the top of the tryner. One '".f these gotes -.xuld bo opposite the inlet cf the discharge pipes and the others T7ould be placed at the one-fifth points bctv^cen that point and the level of the spillir ly crest. Each gate rould be protected by a semicircular tr'-sh T'lck '.Thich could be lifted above the \iatyjT level -..Ith a hjist in the gate house . It is estimated fr-.m tho data obtained from the drill holes in the stream bed, the tunnels int ; the abutinents, and the geological rcpTt by Chester Morliave, that the rem-jval of about 15 feet f -.verburden an', decomposed rock on the abutments and 15 feet ^f sand and gravel in tho strc -.m bed would expose firm r'ck for the drjn f^undrsti ;n. In or ler to decrease the possibility of seepage under the ■^am, a concrete cut-'^ff wall at the upstroam t.^e f the dam would exten-^. 15 feet into the solid r^ck, and bcl )U this wall the foundation rock would be sealed by pressure gr"iuting. It is believed that there is sufficient sand for the concrete available in the vicinity of the dam and that the l^col rock could be crushed for the large aggregate and part jf the medium size aggregate. To make the concrete more vj-.rkable, h:vever, it is estimated that ah ?ut a third of a cubic yard of gravel per cubic yard of cjncrete :7 oild have tc be hauled fr.m the lower end of Mission G'^rge or s^me other gravel deposit, .ill other iTiateri.als an-l equip- -191- raent would prohahly be hauled by truck about 3.5 miles from the railroad ut Lakesi'.le. The TescTv )iT londs nro now practically all owned by the City of San DiegT but their cost has been included in Cill estim-^tes of the costs cf the rcservjirs. Some of those lands are already clear but others would have to be cleared of brush and some trees. Tho only improvement of any importance is the secondary State Highway f r .^m Lakesile to Ramona which runs through prac- tically the entire length of the reservoir and this highway would have to be relocated., A possible relocati m to the west of the reservoir would require about 10 miles of new road. As previously stated, estimates of cost were made for reservoirs created by four different heights of dam. A somewhat detailed estimate of the capital and annU'^l c:>sts for one -jf those reserv .drs, that with a 268- foot dam, is given in Table 39. The loyjut -ml cross sections of this dam are shewn on Plr.te XXI, "San Vicente Daia on San Vicente Creek, a Tributary of San Diego River." The estimated t ;tal capitol and annual costs f.,r the reservoirs with all heights of eravity concrete dams stulied are given in Tt.ble 40. In making these estimates, the same items and unit costs as those given in Table 39 were used. The lay ^'uts f^r all dams studied were similir to that shown on Plate XXI. -192- PLATE, ZZr 4.88J. Ul UOI4.eA3|2 1 TABLE 39 COST OF SAN VICENTE RESERVOIR Operated for Conservation Purposes Crest of iam, elevation 'J2k feet, Capacity of reservoir to spillway lip, U.S.G.S, datum. 174,500 acro-feet. Crest of spillway, elevation 71U feet. Capacity of spillway, Height of dam, 26g feet. 26,000 second-feet. CAPITAL COST Dam (including spillway) Excavation Gravel (including tmwatering) 17, 19^) cu.yds.at $1.50 $25,790 Rock- Stripping 86, 75^^ cu.yds.at 2.50 216,870 - Cutoff wall trenches 5,550 cu.yds.at U.OO 22,200 $26U,g6C Concrete Mass 586,830 cu.yds.at 6. 60 $3 ,873 ,080 Reinforced- Spillway walls 1,230 cu.yds.at 19.25 23,680 - Gate towers and house UOO cu.yds.at 19.25 7.700 3,90U,U60 Grouting, drainage and seals 1,250 ft. of dam at 90.00 112,500 112,500 Outlets Steel pipe - 30 inch U50 ft. at 7.20 3,2UO Trash racks and guides 22,500 Its. at 0.10 2,250 Slide valves in pipe - 30 inch 3 at I5OO. 4,500 Slide valves in tower - 30 inch 5 a't 1100. 5 ,500 Trash rack hoist 1 at 250. 250 15,7^0 Backfill 8,UU0 cu.yds.at O.5O 4,220 4,220 Reservoir Land 225 ,000 Relocation of highway 10 mi. at $36,000 360,000 Clearing reservoir lands 1,450 ac. at 20.00 29,000 6l4 ,000 Subtotal 4,915,780 Administration and engineering 10^ of subtotal 491,580 Contingencies on construction items 15^ of $4,690,780 7'^3>620 Interest during construction 3% rate 408,210 Total capital cost $6,519,190 ANMJAL COST Interest 5 per cent per annum 325)960 Depreciation on dam only 0.35 per cent per annum 20,080 Amortization - Sinking fund 40-year-4 per cent-Semi annual payments 67.280 Operation and maintenance 0.15 per cent per annum 9.780 Total annual cost $423,100 -193- TABLE 40 COSTS OF SAM VICENTE RESEIWOIBS Operated for Conservation Purposes :Elevatinn of : crest of dam, : in feet, •.U.S.G.S. datum Height of dam, in feet Elevation of water surface, in feet Storage capacity of reservoir, Cost of reservoir : In aTe- feet In millions of f;allons Capital Annual : : 665 : 690 : 712 : 724 209 234 256 268 655 680 702 714 100,800 130,000 158,400 174,500 32,850 42,360 51,620 56,860 $3,912,000 4,904,000 5,814,000 6,519,000 ^252,900: 317,600: 377,100: 423,100: Miss_ion l^orge No_;_ 2 Reservoir - The I;Iission Gorge No. 2 reservoir site is located on the main San Diego River in the upper San Diego River Valley. It lies almost entirely within the El Cajon Rancho or Grant. The dam site is located in the upper end of Mission Gorge in Ex Mission San Diego Grant about one-half mile downstream from the line between this grant and the El Cajon Rancho, and the reservoir site extends to a point in the vicinity of Santee. The location of the reservoir site is shown on Plate XXTI. A topographic survey of the reservoir site to the 330- foot contour, U. S. Geological Survey datum, was made by the La Mesa, Lemon Grove and Spring Valley Irrigation District some years ago, and the 360 and 400-foot contours were surveyed by the City of San Diego in 1921, 1922 and 1930. The water sur- face areas of the reservoir as obtained from the City of San Diego, and the capacities of the reservoir computed from them are given in Table 41. -194- TABLE 41 AREAS Aim CAPACITTSS OF MISSION GORGE NO. 2 BESERVOIE : Depth of water Water surface Area of Capacity of : : at dam, : elevation water surface, reservoir, : : in feet of reservoir, : in feet, U.S.G.S. datum in acres in acre-feet : • 46 : 290 : 81 : 1,000 : 56 : 300 : 210 2,400 : 66 310 425 : 5,600 : : 76 320 : 754 11,500 ; : 86 330 1,179 21,100 : 92 336 1,550 29,200 : : 96 340 1,794 36,000 ; : 106 350 : 2,520 57,500 : : 116 360 3,320 86,800 : 126 ; 370 4,200 124,400 : A map of the dam site on a scale of one inch equals 100 feet with a contour interval of 10 feet, obtained from the City of San Diego, was used in laying out and estimating the costs of dams at this site. The geology of the dam site has been studied recently, in connection with the preparation of this report, by Chester Marliave, In this study, he was aided by information obtained from the City of San Diego on eight holes, with an aggregate depth of about 300 feet, drilled into the stream bed and bottom of the canyon and ten tost pits dug on the abutments. Further exploration of the dam site by tunnels and drilling should be made before the final location for any dam at this site is selected. Sufficient funds for such exploration are Included in the it^ns for engineering and contingencies in the follor.ing cost estimates for tho reservoirs. A description of the geology of the site, as taken from Chester Marliave 's report, is as follov7s: "The Mission Gorge No. 2 dam site lies near the western edge of the Penixisular Range. This ranee is for the most part composed of old crystalline .195- rocks in r/hich metamorphism has taken place to a considerable yxtent. The rocks of the granitic type predominate but included in those ig-neous intrusive types are some contemporane.'jus sediments which, due to heat and pressure and age, have become fused into the i^eous rocks presenting a mass of v/hich the original constituents have partly lost their identity. "The general structure of the granitic mountains is considerably crushed which had aided weathering and decomposition of the surface of the mountain mass. Faulting has been responsible for much of this crushed con- dition because it has divided the region into blocks which have moved dif- ferentially thereby subjecting the rocks to distorti m. "Seismic activity is prevalent in the southern portion of the State but most of the active faults lie off the coast or else some distance to the east of the area under c ^nsideration. Some of the geologists T.'ho have studied this area believe that a major fault runs do7;n the canyon of the San Diego River and have so delineated its location upon maps. This cann )t be checked in the region under consideration and it is believed that the evidence is to the contrary. A fault is also njted upon some of tlie maps of this region as passing in a nc'rthwesterly direction across the river about a half mile up- stream fr.^m the proposed dam site. This fault has not been investigated as its probability end activity are d ubtful and ■-'f little concern ti_ the c msideration of a dam at the suggested location. "The :;Iission Gorge No. 2 darn site lies in an area of granite about 4 miles by 2 miles surrounded by various other f -^i-raations. This granitic rock is a portion ;f the crystalline complex while most of the surrounding rocks are recent sedimentary formations that overlie the granite. The San Diego River is at the present time in the process of cutting its course through this granitic area. Commencing about 2 miles below the mmth of Sycamore Canyon, the river -196- 3'^-T' enters a gorge and continues in this narr .v; cany )n for ab ->ut 3^ miles where it emerges upon the mesa lands that front the range and continues fur abuut 7 miles tc the ocean. The djwnstream half :>f this gorge is a volcanic series V;hich, like the granite, has withstood erosion m.re than the adjacent stretches of the river. Because the river in passing thr ;uKh this f?orge is n :\% in the process of degradation the cany^jn is deep and narrow and there is little channel material strern along the bottom. "The channel section at the dom site under consideration is about 200 feet wide at the streara bed, but the actual low water sandy portion of the bed is only about 75 feet wide. The present channel of the river is against the right side of the canyon and the 125 feet of river bottom against the left side of the canyon is the portion that is now inundated only at flood stages. This left portion of the channel section has a rising slope and is covered to a con- siderable extent with boulders and gravel. Along the lower slope of the right abutment the bedrock is exposed all along the edge of the channel section. The estimated average depth of stripping and excavation to reach solid footings for a dam in this section is between zero and 15 feet, "On the left abutment of the dam site, there are quite extensire granite outcrops some distance above the stream bed. There is considerable talus near the lower portion of the hill slope just above the county road which passes along the toe of slope on this side of the river. That this talus is not thick is indicated by the presence of bed rock just below the road fill. Just above the road there has been one small land slide about 300 feet downstream from the probable axis of the dam. 7/ith the exception of this, there is little evidence concerning the structural conditions of the bed rock on this side of the canyon* As nearly as can be ascertained from surface indications, a total of about 20 to 35 feet of stripping and excavation, normal to the surface, will probably be necessary on this abutment in order to obtain -197- satisfactory foundation for a masonry dan, "Tlie rifht side of the canyon exhibits ::ore of the structural conditions of the rock than the left side, Hore there is little vegetation and no trees are found. Several systems of fracturing or jointing occur alone the lo\7er slope of the canyon and are well exposed adjacent to the stream channel. In t?/o of these localities, there has evidently been some crushing or movement along the joints for the open fracutures are filled with crushed material and run-up the hillsides whore they disappear under the talus on the liill. Five shallow test pits were dug on this side of the canyon some time ago, Theso test pits merely indicate the depth of loose overburden whereas the iiiost imnoi'tant conditions to bo explored are the extent of the open fractures which might extend deeply into the hill and necessitate the removal of large masses of sccningly sound rock. The hillside on the right abutment is quite even and rounded shearing deep decay and weathering of the rock. The change in prorainoncc of the fracture systems indicates that there has been crushing throughout the mass. The prominence of the various systems of fractur- ing generally changes abruptly at the open fractures, which indicates possible movement along these fracture planes. This condition, howevci-, is local and docs not affect tho integrity of the abutment as a ■■.hole, "It is believed that none of the fractures extend deeply into tho hill and, on this assumption, it is estiiaatod that excavation and stripping to a depth of about 35 feet, njrr.al to the surface, on this abutment will expose rod: suitable for the foundation for a masonry dan, ■'The dam site presents no natural facility for a spillway removed from the dan, Tho abutnr.cnts are high and steep on both sides. The rock in the channel section, however, is hard and massive and v;ould rcr.dily stand ovcrpour with a little protection," -198- Since the canyon walls at the darn site are relatively steep and the conditions for the construction of a spillway around a rock fill dam are not good, the only t^-pe of dam considered was the gravity concrete, with the spill- vray in the crest c^ the dan. Estimates ha^a teen made of the costs of reservoirs with dams 109, 122, and 151 feet iu hej !>ht from str ■^ U <]} 4^ c • • * • • * • rH OJ ^^ o ^H CJ r-{ r- r-l er> CM ^ N 0) PL. O O O C\i C\J N to rH "^ to •w 5 ■r-< 01 o a> • • • • •• • • •• • • • • • •* •• • ■ ft •• • « •• O «M c: tn o o O O o o o o o o Vi .ti o :: C\J :o CO CM t^ ,-A tj> r-H 00 tjl += o to ^ -H o • • • • • • • • • ft 'f-t d) r-H f-H CO to C7> o to ^ 'd" C^ CM o £ '-I CW i-H <-l CD CO tv CO in to r-l c\? (T> t- d •rH 03 .. f. '^ *f)^ r-H r-\ r-t CM •-t >H o o o o o O o o o o +3 1 C-- f-l o r-H 'D c^ <:i< l-t CO tv •fH Q) +J • • • • • • • • • • •ct ^. tl O CO c^ lO to r-l CO r- "vC CO in ■c* OJ o o C\i CJ N CM in vf co c^ to in "i Oi 03 t„ =fO- " ^' 2 >J .. .. g .. o O o o o o o o o r-l o d c* o o O o o o O o o o nj ?^ -rH O •d «l o O o o o o o ^ o e; tz! OJ r-l 1—1 CD fl^ •t «k •^ ■^ c^ r-f O r-H Ph rH r-t fn CT> (71 oi r-l en rH to" CO cr> C^ ■r- 03 •r-l 05 O ^i* ^0 •* in CO tv to c^ s.. (T> 4-> -H 1. ?. v: P. .. .. „ .. vj* <* 1*. 00 t^ to rH -p C O o 2 o o o o o o m ■d 0) 1 (i r-l o •* t^ •^ CM to o en O cS «-i o +^ ^ • • • • • • • • ft ft o ^ ti ^ o ^ (7> r-l OJ CO 00 CM in si' 'X> tn tn CO (T> •J* t^ to .— 1 o PL, nJ trH .. ..%.. '^J' ^ -^j* I>- tD in 5 o^ 00 -P 0) " " ft. ft. ^ iO 1 O o o g o o o o o o Oj cS (U -p en r- c^ -d* •* -J< to in rH CO O tM Sh u u o » • • • • • • • ft • o o 03 t) O CO c^ <^ r- CO r-{ 0^ in ■^ to ■p (li 03 «-> to CO iO CO r^ s> to CM CO to =e?t t-i .. ^ o o o o o o r> O o .-H o o o o o o o o O o o3 a» U3 r-l r-H CO cr> CM r^ CO rH ^ •« *. •^ •I •t 9< •« * •k ji <^ r- t- CO c- IV C^ C- to CO h c iD i-H c>- CM ^■5 CO r-i tO r-{ c^ •H ^ C\J to co 'i' rH rH CM CM fj lO Cm o ;^*f^ O > o o o o O o' o ' CD o o -P Q) r-l o o o O O o O O o o t,i tn o3 o o o o O o O o o o O 0) -p *> ** ■> •^ •t •^ •k * •> » u t, ■H Oi •^ "=f CJ> to o in to o OD & .-H o r-l rH -^ to CO to c- c .5? o» o^ 00 in r-A at ^ to 00 CO o •\ •( •^ •K •. 9i * M » »t to >;i< ul to CM CM ro ■n sj< in -"> Q) CO n ^> tM C S d ^D iD <* ^ r-l <* CO > OJ -P h o o o O o o o o o o •H ^ 0) Sh :fl 00 t* lO CM c>- to 00 CM o :^ -d O QJ Q) G) •k . *. » •i •* A •» M « •^ -c! -^ =M ft >> CO ,-¥. ^ to CM 'i> in to in 'O ^ -a; r-l i-l rH •* to *' " >» r; tn o o o O O o o O o o +J o C! in U3 CJ to ^ f- CO CM c^ ^ •H fl -H o CO to •-0 CO la c^ CM in CO in O H .— 1 tn 1— 1 » « •t * • •^ •« M * d .-< o r-l cvT cv r-H to (T> CO TO en aj CO ni •M OJ CO <* a> in r-i ClJ r-t CO ^ .. f. M 09 4^ 0) o o o o o o o o o o bO 0) o o o o o o o o o o ci £3 «M CO o ># in CM to CO CM en to U 1— 1 1 •t «s •v •D •r «^ •« » •t •t o 0) o o CO 'd' CT> I>- tD a» t> r- -p ^ o n u-5 r- CM in CO CM in co CO O r— 1 r-l - rH r-4 ■p o O 5 c1 -J h r-4 •H (0 CM •rH OJ U +3 o 0) 03 QO m i»o CO to 0) • H 0) S o 03 U 03 ^H £ .« to O) C3 -rH •H O •HO So • , f^ • • •■ *• •• « • •• • » •• • • • « . ?. ?. .. .. •• •■ •• • "4 CJ3 T:< rH ft «• •• •• •• r^ftft • « •• «• •• -218- • f ' • • • • • PLATE ZXn Cost in millions of dollars Capital cost m dollars 0.3 0.4 0^ 35 37 39 1 lAH Annua 1 cost .IDA Per acre-foot lOU 1 / / a! lOU — / / a> 1 ' u / V- [CTi / V- ■An 1 0) tOv t / (V lov- t i- 1 / i- I u 1 / o I fO / nj \ «.- / / 1 s- ^ o Annual cost / / o L ■D / / •D y c lAfi 1 J 1 / C jAn \ 140 / 1 / nj T*Kl — \ D 1 1/ 3 \ O / / Capital cost O \ C / / c \ >1 / / >1 \ ♦— / / ^- \ 1"^ / / re J 70 \ ^lw — \ Q. / / a \ m / / re \ o / / O \ / / COST UNIT COST \ / / OF or \ inn ' RESERVOrR -IIVl STORAGE \ IMS/ i Capita cost i ( 1 1Uw 1 Cost in dollars Cost in dollars AOO 450 500 550 Per acre-foot per year 25 30 35 40 Per acre-foot lan j CAPITAL COST ifin UNIT COST lou ADDITIONAL SAFE YIELD -iou~ ADDITIONAL SAFE YIELD WITH WITH RCSERVOIR OPERATED RESERVOIR OPERATED «> COGRDINATEILY WITH ^ COORD! NAT ELY WITH CUYAMACA AND LL CAPITAN QJ CUYAMACA AND EL CAPITAN RESERVOIRS ^ RESERVOIRS -16? 1 itn _; 1 I. -|DU — i o 1 , u 0! re ^ H- 1 o \ o 1 1 U1 \ \ U1 I ■ \ T3 \ \ T3 \ \ c' \ \ C \ \ O 1 Ai> \ \ re o -140- \ \ iHU \ \ \ \ ^ \ \ -C \ \ ■^ \ \ \ \ c \ \ Cost permilfion c \ \ Cost per >, \ \ gallons per day >1 \ \ million gallons 120- \ ^ re -120- \ \ \ \ \ \ ' Q. 1 \ \ Q. \ \ Cost per \ acre -foot \ \ re C ac ost p«r\ \ per year \ \ \ \ inn \ inn _ \ \ Per mini on gallons 3er day 100 - Per million gallons 400.000 450,000" 50(i,000 ' 550,000 7 80 ~ 90 100 1 1 COST OF RESERVOIR CAPACII ^Y AND SAFE YIELD FROM SAN VICENTE RESERVOIR safe yield, however, are very flat and it is not believed that if data for points inteimediate to those used were available, the shapes of these curves would be materially changed. The data in Table 47 and the curves on Plate XXIII indicate that between the limits of reservoir capacity studied, the unit cost of storage and the costs of safe yield decrease with increase in reservoir capacity, and at approximately a uniform rate. No curves to compare the unit costs of storage and capital costs of additional safe yield for different sizes of reservoirs at the Mission Gorge No. 3 site have been drawn. Curves which compare the capital costs of reser- voirs of different capacities and the unit costs of adoitional safe yields from these reservoirs, however, are shoTjn on Plate XXIV, "Comparative Costs of Reservoirs on San Diego River." The romcrks in the foregoing paragraph rela- tive to the shape of the curves for the Mission Gorge No. 2 reservoir also apply to the curves for this reservoir on Plate XXIV. The data in Tr.ble 47 and the curves on Plate XlvCV indicate that for the Mission Gorge No. 3 reser- voir between the linits of reservoir capacity studied, as for the Mission Gorge No, 2 reservoir, the unit costs of storage and the costs of additional safe yield decrease v.'ith increase in reservoir cajiacity. Comparic.oiis of the additional safe yields, total capital and annual costs, capital cost per acre-foot of storage, and capital and unit costs of additional safe yields, for resorvoirs of several capacities at the San Vicente, Mission Gorge Ho, 2, and Mission Gorge No. 3 sites, when each reservoir is operated coordinatcly with the Cuyamaca and KL Capitan reservoirs, arc given in Table 47. Graphical comparisons of the total capital costs and costs per acre-foot of additional safe yield for roservoirs at the three sites are sho\7n by Plate XXrv'. The table shows that for equal capacities of reservoirs at the Mission Gorge No. " and Mission Gorgu No. 5 sites, the additional safe yields with the latter reservoir arc somewhat greater than with the former, -219- PLATES XXm AND XXE? j.33j.-3JDe JJ3 spuBsnoMi ui Xipedeo j.saj,-3j3e >o spuecnogi uj ^iioedeo > cc CO 1- o in o o LJ o Q hi z > < u. CO 1- O < 7 cc O < Q. 10 5 DC O O o > CC UJ {/) UJ DC o 1- : YILLD (ATED WITH CAPITAN S A O 60 7 r acre-foot UNIT COS ADDITIONAL SAFI WITH RESERVOIR OPE COORDINATELY :SERVOIR u So o c M O o °= .^ ^ c O o ^— -^1 c < > c Tt m ! f > = ■4 ' 1 ^i ? ; i i 3 ;33>-3j3e jO spuEsnoqi ui < CC 10 UJ r; z Both the table and plate, however, show that the capital cost and unit cost of additional sr.fu yield for reservoirs at the Mission Gorge No, 3 site arc much greater than for rcscr*-oirs at the Mission Gorge Ko, 2 site, for either equal capacities or yields. The Mission Gorge No. 2 site, therefore, is nore cconanic than the Mission Gorge No. 3 site for the lowest reservoir on the Son Diego River. Costs and yields for reservoirs at the San Vicente site V7ere not estimated for as small capacities as at cither of the Mission Gorge sites, since the San Vicente site is too good to be used pomonently for a Sjiall reservoir. If it should prove desirable to develop only a part of its capacity at first, the dcm could be built in such a manner that it could later be rniaadto f'.ill height. Comparison of coit cf additional s.-.fe yield from such a partial development, Tith the cost of an equrl yield frcm Mission Gorge No. 2 reservoir, has not been made. The data in Table 47 and the curves on Plate XXTV, houevcr, show the comparison of the capital costs and the unit costs of additional yields for different sizes of reservoirs at the Son Vicente site to the s^jne costs for the Mission Gorge reservoirs. The curves for uni t cost of additional safe yield on Plate HZVf indicate that for capacities of Son Vicente reservoir equal to those for Mission Gorge Ko. 2 reservoir, the cost per acre-foot -ould be considerably less for Son Vicente reservoir than for Mission Gorge ITo. 2 roscrvoir. The foregoing comparisons of the Son Vicente, Mission Gorge No. 2, and Mission Gorge No. 5 reservoirs arc based on each being operated separately, but coordinatcly, vrith the Guyrjnaca and El Capitrji rcsorroirs. For the full devalopnent of the Trator resoiarccs of the San Diego River Basin, however, both the Son Viccrtc reservoir and cither the Mission Gorge IJo. 2 or Mission Gorge No. 3 roser-zoir \7ould be operated coordinatcly -.Tith the C^yonaca and El Capitan reservoirs. It is therefore important to determine the best division -220- of storage between the San Vicente and I.Iisiuon Gorge reservoirs to furnish the additional yield at the lowest cost. Studies were made for four combinations of capacities for the Mission Gorge No. 2 and San Vicente reservoirs, up to and including 174,500 acre-feet in the latter reser-zoir, the maximum utilizable capacity of this reservoir for tho conservation of San Diego River Basin water alone. These capacities are given in the first throe columns of Table 48. The additional safe yields given in the fourth and fifth columns of the same table are those shown in Table 35, and the methods by ^Thich they were obtained have been previously described, Tho combined capital and annual costs of the two reservoirs, and the capital and unit costs of the additional safe yields from their coordinated operation are also sho'.vn in Table 48. A graphical comparison of tho unit costs of additional safe yields with the different combinations of capacities is shown by the curves on Plate ZXV, "Unit Cost of Additional Safe Yield from San Vicente and Mission Gorge No. 2 Reservoirs Operated Coordinatcly with Cuyamaca ;and El Capitan. Reservoirs." The curves show that tho costs decrease as the capacities of San Vicente re- servoir increase and those of Mission Gorge No. 2, reservoir decrease. The limiting minimum capacity at the Mission Gorge site, however, is 29,200 acre- feet, which is the storage space required to control the run-off from below the San Vicente and El Capitan reservoirs. As previously shown, the safe yield from the basin can be increased 1,300 acrc-fect per year by increasing the capacity of San Vicente reservoir from 158,400 acrc-fect to 174,500 acre- feet, while maintaining the capacity of tho Mission Gorge No. 2 reservoir at 29,200 acre-feet. V/ith this increase in capacity, the cost per acre-foot of additional safe yield would increase from $29.90 to .'550.30, or only about 1.3 per cent. As a further comparison of the Mission Gorge No. 2 and Mission Gorge No. 3 reservoir sites, costs of additional safe yield were estimated using -221- ^ g to •r-l O s» u Q> 0] « 43 •H O 33 ' %• *• ■ c: n c »* CO 00 .-i • • • • • •d tl r-l r-l r-l (7» l-i tn r- iH QJ r— 1 rH o» (y> a> 5 -p ,® • • c ■• •• • «• •• •• *« «• •• •• «• Cm :=> 1 1-1 •^ o» CO rH aj U 10 -i^ * • • • • C2 » +3 c as 1 -^ f-l T-l -d •^ •\ * :s ,-i '4< C\2 00 r-t 1 .. .. .. (POO tn I-H VO ^ Aj oS «rH lO in "* '^ a =«5 CO rH oir c3 r-H lO cn en N ^ «^ «• •v •» •k -5 Ci lO ^ » > t-- r-< U3 ^1 4- in in in U3 1 u •• «• «• • •• • •• (• •• 4 ■^ c^ rH a +J •k « •« •k «^ -p •H c- 3 tv C\J in to a 'd' in tj 00 d tn CO CT> ■D rH * «^ •\ •1 •^ 1 ■C0-- ^ r^ t- CO 1 • •• •" CO C 03 >> CJ rf CO « td C\2 CO tM •M xJ «£i en to UTj C^ (d r-t V-l rH • • • • • tn rH rH ^H W t^ uT •~o VD •H ca Q) rH rH r-t l-t rH onal eld, S E^;: a " " % -H -rf J -^ ^ © -p a> ^ 0) ^ 0. a "-^ CJ <£) Ci uT 00 H ij c *• •1 *. •s •r^ d -d .-tj tn f.. '^ uO c- CO CO 3 ^ r-\ r-A rH rH M 1 " U ^ II •H 1 to lO C^ tN 1 .i^ > A •k •s * D ^ -P V, c>- ^- IV CO CO i 0^ QJ 00 00 co i ^ m CO r-l i-i ,-t C\J C\J f 'r-l CD rvo PI N CO (D +3 . U -3 * u M (C C -H C .rl S h 0) * •^ •^ •n > -d & - 1 CO Q) ^^ C^ cr> en CO © M aj en ch fl) to J)0 0) CO lO C\J C\J to tiD a> si r-t 43 oi U •rH fH CO ■H ^^ CO -p -rl a 4^ ^ •» •s •I C8 a ^ u 00 «* •* U CQ OJ t<5 u> c- c>- m r-i t-t rH rH rH •rH > m •* *• •• ** • m •• • •« • • •• • • •• « • ■• •• •• «« «« •• «• «• -222- PLATE X2CZ 'o > in 0) ID ^- I Q) L O (0 -57,600- 0. £ o ID c o w o O -29,200 Cost in dollars per acre-foot Mission Gorge No. 2 " 29,200 ac San Vicente - 174,500 acre-feet^ 90 94 I 98 lOZ 130,000 - 158,400 196 110 I Cost in dollars per million gallons +- u > M- L 1 a; H) 0) I_ . OJ -+- > (0 Q_ c (0 (D lO UNIT COST OF ADDITIONAL SAFE YIELDS FROM SAN VICENTE AND MISSION GORGE N?2 RESERVOIRS OPERATED COORDINATELY WITH CUYAMACA AND EL CAPITAN RESERVOIRS San Vicente reservoir with a capacity of 174,500 acre-fcct, and Mission Gorge No. 3 rcscrYoir '.vith a capacity of 29,200 acre-fcct instead of Mission Gorge No, 2 reservoir \7ith the same capacity. The costs obtained v«ith this study arc shovm in the last lino of Table 48. Comparison of the costs with those in the next line above in the table for the same combination of capacities using Mission Gorge No. 2 reservoir, shoT7s that if Mission Gorge No. 3 reservoir with the dam at the lo\7er site -.ere used, the cost of additional safe yield would be about 16 per cent more than if the Wo. 2 site were used. This con- firms the former conclusion that the Mission Gorge No. 2 site is more economic than the No. 5 site. The foregoing studios indicate that the best Tvater storage capacities for San Vicente and Mission Gorge No. 2 reservoirs are 174,500 acre-feet and 29,200 acrc-foct respectively. It has been pointed out, hovrcvor, that if the estimated yields are to be maintained over a long period of time additional space will be required in both reservoirs to care for the storage of silt and debris carried into these reservoirs and El Capitan Rcsor'.^oir. The effect of the addition of this space '.vill be to increase the cost of the reservoirs v^ith- out increasing the safe yield, md to increase tho unit costs of safe jdeld somev;hat over those shown in the foregoing tables. In determining the ultimate capacities and -lethod of operation of reservoirs in the San Diogo River Basin, the possible storage of w^ter imported from other watersheds should be con- sidered and the capacities ,and methods of operation modified to meet these storage requirements. AdditionrJ. storage space nay be provided in Srai Vicente Reservoir at relatively low cost. Flood Control 7/orks The methods of estimating the probable sizes, frequency of occurrence and characteristics of flood flows in the San Diego River Basin have been dis- cussed in Chapter V, and the probable flows which may be expected to occur at -223- the Diverting Dam, Mission Gorge, and San Diego have been listed in Tables 27 and 29 in that chapter. In Chapter V, the general effect of conservation reservoirs on the San Diego River in reducing flood flows below Mission Gorge, the effect on the conservation values of reservoirs on the river from their joint use for conservation and flood control, and the effect of reservoir space utilized primarily for controlling floods are also discussed. The reservoirs which would have an appreciable effect in reducing flood flows in the Stm Diego River are El Ca.jitan, San Vicente and Mission Gorge. The San Diego River drainage basin, therefore, has boen divided into four subbasins for the purpose of estimating the effect of these reservoirs on the flors at Mission Gorge and San Diego. These are the two basins dircct- Ijr tributary to the El Ca-itan and Scji Vxccntc reservoirs, the portion of the San Diego River Basin tributary to the river bclov; tho El Capitan and San Vicente reservoirs and above Mission Gorge, and the portion of the San Diego River Basin tributary to tho river below Mission Gorge, The probable flood flows originating in each basin have been estimated and average hydrographs of flow have been selected for each basin by the methods described in Chapter V. The hydrographs of tho probable oncc-in-100-ycar floods at the outlet end of each sub-basin and from each sub-basin arc shown on Plate T/^TL, "Hydrographs of Probable Oncc-in-lOO-year Flood in the Srji Diego River Drainage Bnsin." The hydrographs of floods of other frequencies arc similar to these in shape. In liVatcr-Supply Paper 426 of tho United States Geological Survey, it is stated that the crest flow of the 1916 flood passed Lal:esidc botwcc;n 2:00 and 4:00 P.M. and S-.n Diego about 7:00 P.M. In combining the flows of the separate sub-b asJns to obtain the probable total flows at Mission Gorge and San Diogo, it was assumed that the crest flow from the area between the San Vicente and El Crpitan dan sites and Mission Gorge would reach S-:Ui Diego two hours after the crvjst flo'? from the area below Mission Gorge; that the -224- PLATE XXVr 50 ^~ 1 SAN DIEGO RIVtR 4-' a; Natural fic "xA AT ELCAPITAN DAM thousands of-second- O O O 1 ' \ ' 1 ' \ / ' \ / ' \ \ 1 f 1 / / / / / 1 / 1 / 1 \e o* feel O » M :^ fOWTTTOCHTCM (OVEMENT AND RELOCATION FOR U DIEGO RIVER BAY TO PRESIDIO HILL SCALE Of FEtT Rum IS siandara lower lo* water btract ? 89 *pef 'c U "i G ^ eipvai.cn^i PLATE XXVII ! •r^x::^'H i ! H.CHHAI •■•SC( ; I WOWexik BLVO ^ OUII"*' -f i /-y\ V 1 V 1 i — -'--- ■'r'."s:v .«._o.o™„^ - . i--^.^ ,,^.->S'/°";j.'^.^^ Sg* SUnaarO lo-er ' Jow oBter 1 " 1 '.o,^-"'o.c>..>,f-^ ' K- , Along e.rH.rlm« J of north!,.*, 1 iOM 00 ^ to 10 lO 00 lU oo I* 00 00 00'^ cu.yds. at Overhaul 728,000 sta.yds.at Borrow for levees .^0,000 cu.yds. at Levee protection - Crushed rock 37i600 cu.yds. at - Rip- rap ll6 ,000 cu.yds. at Road crossings Ingraham Street Alternate Road - Fill 3;0,000 cu.yds. at - Paving 200,000 sq.ft. at Bridge - Excavation 5>000 cu.yds. at - Wood piling 35,000 lin.ft. at - Concrete - Pier footings 1,100 cu.yds. at - Piers 1,3^0 cu.yds. at - Deck 1,500 cu.yds. at - Rail 60 cu.yds. at - Steel - Structural 6l5 tons at - Reinforcing 150 tons at - Cast 20 tons at - Traffic stripe 2,^00 lin.ft. at - Curb stripe 1,600 lin.ft. at - Pier protection - rip- rap 1,200 cu.yds. at Atlantic Street Bridge - Pier protection - rip-rap 1,200 cu.yds. at 2.50 3,000 3,000 Morena Boulevard Extending bridge $C.1S $165 ,100 0.01 7,300 0.15 12 ,000 2.50 9U,ooc 2.50 290,000 $568,^00 0.15 12,000 0.20 kO ,000 1.00 5,000 o.6o 21 ,000 lU.OO 15 ,^00 15.00 20,100 lU.OO 21 ,000 l+O.OO 2,U00 120.00 73,800 100.00 15 ,000 200.00 U.ooo 0.25 600 1.00 1,600 2.50 3,000 234,900 - Excavation 2 ,800 cu.yds. at 1.00 2,800 - Wood piling 5 ,000 lin.ft. at 0.60 3,000 - Concrete-Fiers and buttresses 1 ,120 cu.yds. at 15.00 16, 800 . - Deck 200 cu.yds. at 15.00 3,000 - Steel - Strxxctural 150 tons at lUO.OO 21 ,000 - Reinforc ing lU tons at 100.00 i,4oo iction - riT3-rap 800 cu.yds. at 2.50 2 ,000 50 ,000 -232- ::!'^-IV TABLE 1+9 (Continued) Road crossings , (continued) Santa Fe Railroad crossing Roadbed - Earth fill - Ballast - Raising treck Raising present bridge - Lifting girders- Jacking - Raising piers-Concrete Extending bridge - Excavation - Wood piling - Concrete -Pier footings -Piers - Steel -Plate girders -Floor bear.is -Reinforcing g,000 cu.yds. at 2,000 cu.yds. at 1,300 lin.ft. at dO cu.yds. at 2,5CO cu.yds. at 7,500 lin.ft. at 0.25 2,000 2.00 U,000 1.00 1,^00 U,000 20.00 1 ,2>'X) 1.00 2,500 O.bO U,500 UOO cu.yds. at ik.OO 5 ,600 670 cu.yds. at 15.OO 10,100 150 tons 90 tons h tons at 120.00 18,000 at 100.00 9,000 at 100.00 lt-00 -Deck Bridge pier protection - Rip-rap 40 M.3.M. at 1 ,600 cu.yds. at 350 acres Right of wa;/' Sub- total Administration, engineering and contingencies - 25^ Interest during constraction - 'y.o rate Total cost 75.00 3,000 2.50 h,ooo $70 ,100 at 300.00 105,000 105,000 1 ,031 ,hoo 257, SOO 52,200 l,3Ul,U00 AMUAL COST Interest Depreciation on channel and." levies itoortization - sinking fund Maintenance Levees and channel Right cf way Total annual cost 5 per cent per anntun 0.6U per cent per annum ho year -U per cent- semi-annual payments 2 per cent per annum 1 per cent per annum 67,100 4,700 i3.?co i4,goo i.Uoo $101 ,goo ■233- tatle shows the quantities of work required and the unit and total costs for each item. At the tottom of the table there is an estimate of the annual cost of the channel showing the items of expense, the bases for estimating the costs, and the cost of each item. The estimated capital and annual costs for the channels with the six capacities studied are f:iven in Table 50. In estimating the costs shown in this table, the items of cost and unit prices were practically the same as in the detail estimate shovoi in Table 49. A comparison of the capital and annual costs of the channels is shown graphically on Plate XXIX, "Cost of Flood Protection in Mission Bay Area", near the end of this chapter. -234- TABLE 50 COSTS OF CIiAMN:EL niPROVEI .'ENT AND RELOCATION FOR SAII DIEGO RIVER MISSION BAY TO PRZSIDIO HILL : Capacity of channel • : with 4-foot free- Costs : : board on levees, in : second-feet Capital iVnnual : : 36,000 $1,254,000 $04,300 : : 4?.,700 1,286,000 97,100 : : 50,000 1,326,000 100,400 : : 5S , 600 1,341,000 101,300 : : 71,000 1,452,000 110,800 : : 105,000 1,735,000 133,000 Reservoir Control_ o^f_Flo£d_£ - It has been shown in Chapter V that the use of conservation space in the reservoirs on the San Diego River for flood control is not advisable, as some water which should be conserved might be lost by- such operation. It v;ould be possible, however, to construct the Mission Gorge No. 2 reservoir to be operated for flood control as one of its functions by [SO constructing the dam that flood flows could be stored in reserve space [above that provided for conservation purposes. It has also been deteirained by a number of studies of the operation 'of the conservation reservoirs, that with these reservoirs operated for con- [servation alone there woiald be a material effect in reducing flood flows in [the Snn Diego River below the reservoirs, especially those flows v/hich would occur during the smaller floods. The res^ults of these studies are shown in Table 51. The first column of the table shows the average frequency of occur- rence of the flood investigated. The second column shows the amounts of flow in the river at San Diego which would originate below Mission Gorge, or below the lowest reservoir which would effect reductions in flood flow. The third ■235- ■H> 4^ (U 0) 0.1 0) <^ • ■'-> w ri CO M •H rt CO Q o CO -r-i CO S S ^ CO s O re o h-l (in c w o (X (A *H M C) +^ r-l ^i r-) CO lO > -^ > w G r-i 0) r-J CO :') CO ^ w c « M o n >-1 o o B iVh M w o H IX ;-( M 1 1 i< t-i fn ^ 00 ac 00 ac iO o> C *• CO CO +^ o •H CO ft H CO y CI >> 13 O ^ • • •• - o .V .. .. • • •• • • •• - O • CO o o to" 'i* lO CT> t', O ■HO H to in !>- ri c to f. U rH CO CO W Cn;rj ^=:; o • • «i ' • ■• - t,^ ■R CO 3 O o o o (D >-^ O -PO W 1 o o 1 o —1 1 1 1 1 ■. O -M fj; lO CO O ^ to t) (D O r-H to Pi 1^^ CO a o 1 •H •r-t - H CvJ tiD ■r-t *t •« 91, 0) o o o ^ 1— 1 •H ;> 02 ^jf fO OV « 0) q CO CO o w « CO ^1 CO p; & e . cu O o o o o o cO -P o o o o rH rH C) 'H o «D to C\i <^J iH s & •« o CO «3 ^" ^ C7i OJ tM CO f CV! o Cft r-l >> J3 XI CT ■fJ o •rH CO O o o o o O o o o CO ^ cu o rH g *k •k •« «s CC' ^ c- iH m >. •^ CO 05 C\J 3 rH o til. c ■r-t P o o o O 4^ -H C o o o o CO to ^ O ID CO ■* 0> Oi C CD O -H fcu m •^ ^ •M XJ iH to Ph lo" CO C\J CO tjli (D to Q ■-< C ^ £j c5 fn -r-t g iH rH CQ CJ O CO CO CO to fH u ^ fH CO CO CO c« (D ID CD (D .d 13 pj (D >> >j >> i>i » O rH O 60 rH O -H P CO lO O o o ^ t:^ ;c4 O - U C\i tn o LO CO 03 & e fH 0) rH OJ ,0 ;3 ^ f» O !3<^ e O 05 »-! c C fl fn 4^ O O •H •H •rH •H *li fn -M ^ O CD V • • • • • ( o • • * o o ■236- 1 ! .■ colijmn shov;s the flow at San Diego if Cuyamaca Reservoir were the only reservoir en the river, which is the condition which existed before the El Capitan Reservoir was completed and in operation. The fourth colman shows the flows with the El Capitan Reservoir in operation in addition to Cuyaniaca Reservoir. These are the flov;s which may be expected to occur until additional storage is developed in the river basin. The fifth, sixth and seventh coliJiins show the flows with San Vicente reservoir alone, Mission Gorge No. S reservoir alone, and San Vicente and Mission Gorge No. 2 reservoirs together, respectively, operated coordinatoly with Guyaniaca and El Capitan reservoirs. Differences between the figures in the fourth, fifth, sixth, and seventh columns from those in the third column show the reductions in flood flows duo to the operation of the reservoirs for conservation purposes only. As has been previously stated. Mission Gorge No. 2 reservoir could bo constructed to be operated for flood control as one of its functions v;ithout interference with its value for conservation. Studies have been mtidc to de- termine the height and type of dam required, and the cost of rcrcrvoir, for three controlled flows at San Diego. Those x1ot7E are 06, 000 second-feet, 42,700 second- feet and 58,600 sccond-fcot, occurring once in 100 years on the average. In all cases, the capacity of the conservation portion of the reser- voir ?/as maintained at 2), 200 acrc-feot. The combined conservation and flood control dam would bo of the same general tjrpc, and located in the same position, as the conservation dams pre- viously de.-cribed. The principal difference T^ould be in the lengths and depths of the spillway sections and in the use of steel drum gates in the spillways to control the flows. Statements provioi;sly made with reference to the geology of the site, amounts of excavation required to obtain a sound foundation, scal- ing of the foundation, outlets and sluiceway, and the availability of materials for construction, in describing the conservation dam, also apply to the ■ •237- construction of the dans for conservation and flood control combined, and mill not be repeated. The total length of the spillway and flood control gate sections of the dams for all of the controlled flows studied would be within a few feet ^sf the same length as the spillways of the conservation dams. The spillway channels, therefore, would be the same as for the conservation dams. For the dam required for a controlled flow of 36,000 second-feet, there would be two steel drum gates 12 feet high and 30 feet long, located in the center of the dam. The gates would be separated by a concrete pier 12 feet thick and there would be similar piers at the ends of the gates. Two of these piers would contain the operating mechanism for the gates. The sills cf these gates would be at elevation 324 feet and the tops at elevation 336 feet. On both sides of this gate section there would be overflow spillway sections, without gates, 195 feet in length, with the crests at elevation 351 feet. The top of the dam on the abutments would be at elevation 364 feet. For a controlled flow of 42,700 second-feet, there would be three gates 12 feet high and 40 feet long, separated by 12-foot thick concrete piers, with the sills at elevation 324 feet, and t'.vo overflow spillway sections, without gates, 165 feet long r.'ith the crests at elevation 345 feet. The crest of the dam on the abutn&nts would be at elevation 358 feet. For a controlled flow of 52,600 second-feet, there would be two gates 12 feet high and 40 feet long and two gates 12 ftet high and 50 feet long, separated by 12-foot thick concrete piers, with the sills at elevation 324 feet, and two overflow spillv.ay sections, without gates, 135 feet long with the crests at elevation 336 feet. The crest of the dan on the abutments vould be at elevation 352 feet. The dam last described is shown on Plate XXVIII, "I^'ission Gorge Ko. 2 Dam on San Diego River with Flood Control Features." With all of the dams just described, a flood which might occur once in 1000 years on the average would pass the dam without overtopping the abutments. -238- PLATE XXVIII < I < z o o u to OQ OQ z g H O u ;0 < Q to u o (\J a: o o Ixl h 7 > < UJ Lt u. UJ O LJ Oz 0::° o WITH TROL [«- o uJ O n Z < ° O z 8 lO z o ^ 8 O o _J (/) U. CO 2 iaaj. ui uo!4.eAa|^ The principal it.cir.s of cost for the flood control features of tho Mission Gorge No. 2 reservoir are the yurchaso of additional reservoir lands and the relocations of roads ,md the water supply pipe line. The crest of the dam for 29,200 acrc-fcct capacity for conservation only v/ould bo at elevation 353 feet. The additional heights for flood control are shov;n by tho crest elevations in the foregoing paragraph. For the 52,600 second- foot controlled flo'v, the crest of dam -i/ould be one foot lovrer than the crest for conservation alone, due to the additional capacitj- of the spillway. For this control, the cost of the reservoir "ould be practically tho same as for conservation alone, as hereinafter shoTm, For the 42,700 second- foot control, it is estimated that 75 per cent of the cost of tho flood control features rould be attributable to the purchase of land and tho relocation of improvements. For the 36,000 second- foot control, the cost of these items would be 77 per cent of the cost of flood control features. In order to illustrate the method of estimating the cost of the Mission Gorge Ko. 2 reservoir for combined conservation and flood control, a sorr-cThat detailed estimate is given in T:.ble 52 for the rcsorvoir required to obtain a controlled flov; of 52,600 sccond-fect. Tliis table shows the quantities of "ork required and the unit and total costs for each item. At the bottom of tho tr.blc there is an esti'::iatc of the annual cost of the resorvoir shov;ing the items of expense, the basis for estimating the costs, and the cost of each item. The estimated capital and annual costs for the reservoirs required to obtain the three controllec flo\7s previously stated are given in Table 53, These costs v/ere cstimatod in the seme manner as shown by the e?:timate in Table 52, The items of cost and the unit prices z:oto the snne in rJLl of the estimates. In addition to the costs, the table shows a summary of the flood control and spillway features of the doms and tho maximvnn controlled flows -239- TABLE 52 COST OF r/CrsSION gorge no. 2 RESERVOIR WITH FLOOD CONTROL FEATURES Capacity reserved for conservation, 29,200 acre-feet. Crest of dan, elevation 352 feet, U.S.G.S. datum. Uncontrolled spillway - Length 270 feet, crest elevation 336 feet. Steel drum gate section-2 gates, 40 feet long, gate sill elevation 324 feet, 12 feet high. -2 gates, 50 feet lonp;, gate sill elevation 324 feet, 12 feet high. Controlled flov at San Diego, occurring once in 100 years, 52,600 second-feet, reservoir water surface elevotion 343 feet. Controlled flow at San Diego, occurring once in 250 years, 71,200 second-feet, reservoir water surface elevation 347 feet. Flow past dan, occurring once in 1000 years, 109,000 second-feet, reservoir water surface elevftion 352 feet. Maxinum capaciti' of spillway, 109,000 second-feet. CAPITAL COST Dam (Including spillway) Excavation Connon 14,000 cu.yds. at $1.50 ?^21,000 Rock - Stripping £9,900 cu.yds. st 2.50 74,750 - Cutoff wall trenches 3,910 cu.yds. at 4.00 15,640 - Outlet tunnel 90 cu.yds.. at 10.00 900 ?ill2,290 Concrete Mass - In dam 84,200 cu.yds. at 6.60 555,720 - Outlet tunnel backfill 70 cu.yds. at 14,00 980 Reinforced - Spillway walls 320 cu.yds. -ft 19.00 6,030 - SpillT7ay piers 1,500 cu.yds. at 15.00 22,500 - Spill-.;ay lining 1,010 cu.yds. at 16.25 16,410 - Gate tower end house 100 cu.yds. at 19.00 1,900 603,590 Grouting, drainage and seals 640 lin.ft. of dam at 90.00 57,600 57,600 Backfill 3,980 cu.yds. at 0.50 1,990 1,990 Spillway gates - Steel drum gates 261,000 lbs. - Operating mechanism 4 sets at 1300.00 5,200 31,300 Outlets Steel pipe - 30 inch Trash racks and guides Slide valves in pipes-30 inch Slide valves in tower-30 inch Trash rsck hoist Foot bridges between piers 180 ft. at 10.00 1,600 15,800 -240- '61,000 lbs. at 0.10 26,100 >m 4 sets at 1300.00 5,200 460 ft. at 7.20 3,310 6,400 lbs. at 0.10 640 3 at 1500, 4,500 3 at 1100, 3,300 1 at 250. 250 180 ft. at 10.00 1,600 I TABLE 52 (Continued) Reservoir Land and improveni<^nts L Relocation of roeds Relocation of pipe line Clearing land Subtotal dmini strati on and engineering uontingencies on construction items Interest during construction ?550,000 5.0 mi. at $20,000 100,000 5.2 mi. at 45,000 234,000 500 QC. at 20.00 10,000 ? 894,000 1,714,570 10?i of subtotal 171,460 IS';', of ,^l,16^i,570 174,690 5/0 rate 83,460 $2,144,180 AKtJUAL COST nterest 5 per cent per annum ^ 107,210 Depreciation on dan only 0,35 per cent per annum 3,740 Amortization - Sinking fund 40 year - 4 per cent - Semi-annual payments 22,130 Operation and maintenance 5,000 Total annual cost | 13a, 060 -241- ^—oQ— I / at San Diego which might occur once in 100 years and once in ?.50 years on the average. The last two columns of the table show the capital and annual costs of the flood control features only of each reservoir. These costs are also shown graphically on Plate XXIX. In obtaining these costs, the capital and annual costs of the conservation reservoir with a storage capacity of 29,800 acre-feet were subtracted from the capital and annual costs, respectively, shown in the ninth and tenth colurms of the table. Although it is assumed in estimating the costs of the Mission Gorge No. 2 reservoir for conservation and flood control corr.bined that the reservoir would have the same value for conservation that it would have if constructed for this purpose alone, this is not exactly true. This is due to the fact that there would be no opening in the dam constructed for conservation alone below the storage level for 29,200 acro-feet at elevation 336 feet except the outlet pipes, whereas the sills of the steel drum gates required with flood control operation would be at elevation 324 feet. With these drum gates, there would always be a possibility that their failure to close would cause the loss of some of the water in the conservation portion of the reservoir. Also, with drum gates, there would be some leakage when water is against the gates and, to prevent the loss of this water, it would have to be collected below the gates and pumped back into the reser\''oir. This would cause some additional ex- pense. Farthemore, since drum gates must depend upon mechanical operation, either automatic or manually controlled, neither of which can be perfect, and also since the drum gates can be prevented from opening in the manner necessary for proper flood regulation, their use for flood control cannot be absolutely de- pended upon. To overcome the foregoing objections from both conservation and flood control points of view, it would be possible to construct a dam for combined conservation and flood control use with no openings in the crest below elevation -242- 356 feet and with no movable gates. This is possible through the use of open ports in the dan, with their sills at elevation 336 feet, and overflow spillways without gates. In order to ccsnpare the cost of a reservoir having such a dam m with that for one which would give the same regulated flow by using drum gates I in the dam, an estimate was made for a reservoir with a dam having open ports and spillway capacity to control flood flows to a maximum of 42,900 second-feet at San Diego, occurring once in 100 years on the average. The dam -/.'ould have twenty 8 foot by 8 foot openings in the central portion of the dam, separated by concrete piers 8 feet thick. The sills of the openings would be at elevation 336 feet and the tops at elevation 344 feet. Directly above these openings, there would be an overflow spillway 318 feet in length, with its crest at elevation 355 feet. At both ends of this spillway, and separated from it by five foot thick concrete piers, there would be spillways 40 feet long vrith crests at elevation 345 feet. There would also be two spillways, each 41 feet long, adjacent to the 4C-foot spillways and separated from them by five-foot thick concrete piers, with crests at elevation 355 feet. This gives an over-all length of spillway and port section of 500 feet, the same as for the spillways for the conservation dams. The tops of the abutment sections would be at elevation 363 feet, at vrhich height a flood occurring once in lOOC years on the average would pass the dam without the abutments being overtopped. The other features of the dam wo'old be practically the same as for the dam for conserva- P tion alone. Data and costs for this reser^'-oir are given in the last lines of Table 53. Comparative data and costs for reservoirs "ith 29,200 acre-feet of space for conservation and with features for controlling floods to a maximum flov; of 42,700 second-feet at San Diego occurring once in 100 years on the average, either by means of open ports or drum gates, may be obtained from Table 53. It will be seen that for the reservoir with open ports in the dam ■243- I I +^ 0) o ^ (» CO fH cc o M CO O > o g CO o t/1 w fc w (7> a r OJ w d d" • (X4 o o ■r-t CO s; (-1 •jj lO o X w K p- W o S ^1 M p: (!■ S C) c> CO C5 CI c H o S « o o o M .•:> !h C/) H-l o CO Ix^ tf-A M a ^ Id o e 0) CO CO ^ ^-1 o u •H o CD Ph CO o n • • O *• •« O •• •« o o ai rH o O 5 o h cd CO CO in 13 :3 3 •« M O -U c:; irT c>- CVJ O cp .. ^ N '3' ■5j< ^''Jf " O " O " O '* o <^( ^^ rH o O O 8 o o ID o O O f- p •« «k » +^ +> •f-i r-i i-i CV! CO m c ft rH c- 05 o o l-J 'i* o to o o C^ *> .. ^ O ' O " o rH o o o o CO rH r-i OJ CO 3 «k «^ •» •t C CD e:) in o ^ CO o CD CO ^1 rH f-t .H r-{ li-l -H o o <».'- o o ' O ' o +^ fH o o O o CO o rH o o O o O CO lO »k ■b O 0) +J 'd^' ■* in «D f^ ■H •^^ lO rH CO Cli rH LO Oi CD CO «k A 91. •» u 1:f w CVi w bl) ' CO rQ — - c u o o o o a O r-i •r^ t; CO o o o o o .-{ tj — f-( •r^ B . JC5 IB » •k •» •* O -H +3 ^0) P U <-i CD o ^ Q 0) o O O CU t> in in in ■P CU o c: in c F> O CO 1 o en -o o o w o CO ciL " ra ' vh G ^1 o o o o S -P o ■rH C CO (D o o o o p a o 0> P f-c >. ja CO ^ •k •k •» •r^ g CO 3 r--: ^ -H O O rH O CO '* c - '* ** * •• • " rt O -P c o •H CO o -O -rt P 0) -P «o in rH in in •(H 0) P CO t^ C (U .o '^ in ^i" in +J rH O ;> u ■r^ (D CO lO CO CO to o ,-( 0) QJ iV-4 > C CO U O >> ^ * CO o s X3 p O rH P P o o o o o rH c ^ C -r-l 0) c- CO en CD O rH ID -H w CO 20 •tj- •r^ a. ^ r:* "* 'S* O -rH .H Q) to to CO CO CO O 0) r5 01 CO ^ P c o CO 60 O 3 q }^ " " " . .. o ^1 ^^ p (p +^ C -P P t3 C)0 4-1 -P G (D o o o o O •o c C O CO •r^ 0) '^ Ifi "* CO ft o o O -P 0) bO CD •* CO CO +^ o 3 iC in Uj to F> Pi CO - -P • +3 fi to CO CO 03 o 0) d o CO cd iH -H ^H g 0) • TS w -p o "O -P +J •r( CO a p> U CD G ■H CD ■p (P o O ■rH CJ t 5 ft •rH g CO > Q) CO n CO >, G OJ 3 r-l CO fn O w C/J G O •rt 4^ CO P> u 0) to G o o j:: pi -244- I * ■4- , ^ i ( ■■ , ^ • '* 1 '•■' ■. ** *• •! ** * ^ .f 1 ( 1 i • 1 -■ [ r- - f . « •« ** •• i . • 1 «••» »■ ^••. •••• ,»*1'«a . .••«>■•. •• •* •••* -.4. 1 il *9 «> ■<«• ! -»*.* ^. . i» 1 _i»i • » - • r- the flow line would be 5 feet higher, the capital cost of the reservoir and flood control features ?'-282,000 greater, and the annual costs of these features $17,200 cheater, than for the reoervoir with drum gates for flood control. It has been shown in Table 51 that with the Cuyamaca, El Gapitan, Sein Vicente and Mission Gorge No. 2 reservoirs all operated coordinately for conservation only, the maxirriuin flow which would probably occur at San Diego once in 100 years on the average would be 55,000 second-feet. The foregoing data show that with the same conservation reservoirs but with Mission Gorge No. 2 reservoir also operated for flood control, this flow could be reduced to 52,600 second-feet, 42,700 second-feet, 36,000 second- feet, or to some lesser amount, by utilizing sufficient reserre storage space for flood control in the Mission Gorge No. 2 reservoir in addition to the 29,200 acre-feet for conser- Tation purposes. The reduction of the flows through Mission Valley would give protection to the lands in that area and would decrease the cost of levee protection for the lands, if such type of protection were desirable, Protec_ti_on_o_f Mi£si_on^ ^ay Ar_Ga_by; C_omb_in_ed_Flo£d_C_ontr_ol_ty; Resorvo_irE__and_IiL-_ proyemen_t and Relocation £f_San_DJ^G£o_R_iv_er_C2ianivel - If it is assumed that no levees would be built in Mission Valley, that a leveed channel would be built [through the Mission Bay area, and that Mission Gorge No. 2 reservoir would be [built with flood control features, the costs of flood protection in the Mission Bay area with several controlled flows at San Diego, which controlled flows would also be the capacities of the leveed channels, are given in Table 54. These combined costs are also shown graphically on Plate XXIX. -245- TABLE 54 COSTS OF FLOOD PBOTECTION IN ISSSION BAY AREA With Flcod Control Features at Mission Gorge No. 2 Reservoir and San Diepo River Channel Improvement and Relocation from Prenidio Kill to Mission Bay : Capacity cf r-han-: Costs :nel with minimum :Flood control features: Channel improvement : 4-foot freeboard : of Mission Gorge No. 2: and relocation : on levees, in : reservoir : : T->tal : : sesond-feet : Capital : Annual : Capital : Annual Oapital : Annual : t • • • • 36,CC;> : $772,005 :^7,400 : $1,254,000: $94, ;'nO 42,700 : 411,000 : 25,300 : 1,286,000: 97,100 : 52,600 : 1,000 : 300 : 1,341,000:101,800 : 42,980 : 693,000(1): 42,500(1): 1,286,000: 97,100 .$2, 926, 000: $141, 700: 1,697,000: 122,400: 1,342,000: 102,100: 1,979,000: 139,600: : (1): (1): I (1) With open ports for flood control, instead of drum gates, in I4ission Gorge No. 2 dam. In the discussion of the improved and relocated channel for the San Diego River through the Mission Bay area, it was stated that the capacity of this channel would depend largely upon the time of its construction with respect to the time of construction of the upstream reservoirs, the degree of protection desired, the use of Mission Gorge No. 2 reservoir for flood control as rne of its functions, and the lowest combined cost of the leveed channel and the flood control features of the Mission Gorge No. 2 reservoir. If it is assumed that Cuyamaca, El Capitan, San Vicente, and Mission Gorge No. 2 reservoirs were con- structed to the capacities shown in the heading of Table 51 and operated for conservation purposes, that Mission Gorge No. 2 reservoir wo\ild also be enlarged and operated for flood control, and that none of the costs of flood control by reservoirs would be charged against Mission Valley, the last two columns in Table 54 and the lower right hand curves on Plate XXIX show the cost of flood protection in the Mission Bay area. The curves indicate that the minimum cost -246- JO PLATE ZXEX m =8 in c m n o IT) c c < "5 z o u UJ I- o cr Q. Q o o Ll. o I- o U < u tr < (/I o < m o a. O o CO o ;99|-3J3e J.0 epuesnoqi ui puueqo ps;eoo|9J p /^iobcIgq of protection would be obtained with a controlled flow of about 52,600 second- feet at San Diego occurrinp once in 100 years in the average, and a leveed channel of this capacity with a minimum free b jard of fjur feet on the levees. A channel of this capacity would carry the flood of 71,200 second-feet \;hich might occur once in 250 years on the average with the same reservoirs in opera- tion, TTith a minimum of 2.4 feet of the freeboard on the levees remaining. Although the flood control features in the Mission Gorge N'^'. E reservoir for a controlled flw of 52,600 second-feet occurring once in 100 years nn the average cost practically nothing, this c mtrolled flow is only 2,400 second-feet less than if the reservoir were operated for c :)nservation only. In both cases, the Cuyamaca, El Capitan, and San Vicente reserve irs v.'ould also be in operation for conservation. Since there are disadvantages to operating the reservoir for flood control, as previously pointed out, it would be possible to obtain the same degree of protection in the Mission Bay area by increasing the capacity of the leveed channel to 55,000 second-feet. In this case, the capital cost of flood control to this area '.v xild be about ^15,000 greater than if Mission Gorge N). 2 reservoir were operated f r flood control as one of its functions. If it is assumed that tiie lands in the Mission Bay area will be re- claimed before any more reserv )irs are built m the San Diego River, the flows against which protection sh nild be provided are th"'se with Cuyamaca and El Capitan reserv jirs in 'oporatii-n f:r c ;'nservatijn, sh.v;n in the fourth column of Table 51. The selection of the capacity of the leveed channel would then depend upon the immediate degree of protection desired. If full immediate pro- tection against a flood which might occur once in 100 years ^n the average is desired, the channel should be designed for a capacity of 71,600 secjnd-feet with a minimum freeboard of 4 feet ''n the levees. If, however, advantage is to be taken of future flood control benefits fr'vm the construction of the San -247- Vicente and Mission Gorge No. 2 reservoirs, the channel capacity uould be made 52,600 secjnd-feot, or 55,000 second-feet. If the channel is constructed for a capacity of 52,600 second-feet with a mininum 4-foot freeboard on the levees, the flow of 71,600 second-feet ,vhich may occur once in 100 >ears on the average under present conditions would be carried by the channel with a rciniraum free- board of 2.4 feet remaininfr on the levees. The flov; of 99,200 second- feet •.7hich may occur onco in 250 years on the av-jrage under present conditions would pass down the channel with a miniraura freeboard of about one-half foot remaining on the levees. This freeboard could bo increased to at least 1.5 feet, however, at no, or a very small expense, by slightly decreasing the width of croT-n of the levees and adding the material to the top. Pr£tec_ti_on_of ^i-i^^i^il Valley - The lands in liission Valley subject to overflow comprise practically all of the relatively flat lands adjacent to the San Diego River froir. Morena Boulevard to the lower end of Mission Gorge. Most of the lands, except those occupied by the river channel^ are used for agriculture and there are only a few residences and buildings within the area which may te flooded. Above the mouth of Alvarado Canyon, the valley narrows considerably and any leveed channel through this area, sufficiently large to carry the flood flows, '.vould occupy too large a portion of the flooded lands to justify its construction. Therefore, no flood protection except that obtained from upstream reservoir operation is proposed in this latter area. Flood flow studies of the San Diego River shov: that the crest flows from the side canyons which enter lower Mission Valley precede the crests from the upper river by several hours and therefore have very little effect in in- creasing the amounts of the crest flows throiigh the valley. Crest flows, for which channel capacity through the valley below Alvarado Canyon would be pro- vided, would, therefore, remain practically constant from immediately below the -248- mouth of this canyon to Ivlission Eay. These flotvs under present conditions and TTith the proposed reservoirs constructed and operated for conservation are shown in Table 61. It may be seen from Table 51 that under present conditions the flo;7s through lo-er J.a.ssion Valley would be 26,000, 46,600, 71,600, and 99,200 second- feet once in 25, 50, IGC, and 250 years on the average, respectively. The table also shows that with ?uya.T^''a, El (iapitan, San Vicente and Mission Gorge No. 2 resorvoirs operated for conservation, the flows would be 13,800, 34,600, 55,0©0 and 79,000 second-feet, once in 25, 50, 100 and 250 years on the average re- spectively. The smallest of t::ese flo-.vs rvonld cause soir.e flooding adjacent to the channel and larger ones Tjould flood practically all of the valley lands. To protect these lands, therefore, a leveed channel through the valley would be required. The size and capacity of this channel -.'ould depend upon the time of its construction with respect to the construction of the upstream reservoirs and the degree of protection desired. In this study, only nne size of channel was investigated. In estimating the cost of the leveed channel thj-ough I.iission Valley, it v/as assumed that the cost of lengthening the Morena Boulevard Bridge vras charged to the improved and relocated channel through the I.lission Eay area and that the north levee of the latter channel was constructed to high ground about 2000 feet upstream from the Klorena Boulevard. The north levee of the Mission Valley channel was tied in to the north levee of the Mission Bay area channel about 1000 feet east of Morena Boulevard. The south levee v.'as started 1000 feet east of the south end of the Morena Bridge and carried along the Gamine del F.io, to form an embankment for tlis.t road, for about 2000 feet. The channel was laid out to follow in general the lor; nater course of the river. The south levee vras terminated at high ground near the south end of the San Diego River bridge on -249- tho Niurphy Canyon Road. The north levee was terminated at high ground near the San Diego r«;ission. Lovees were extended up both sides of the Murphy Canyon channel to the county road, to divert tho flow from that canyon into the flood channel. The north levee of the flood channel was carried up the west side of the I-!urray Canyon channel to the county road and the road fill vas raised to divert the flow from the canyon into the flood channel. On the cast side of Murray Canyon, the ground is high enough to serve for the north levee of the flood channel for several hundred feet. The channel was designed for a carrying capacity of 72,000 second-feot, Trhich is approximately the estimated flow once in ICO years on the average under present conditions, with a three-foot freeboard on the levees. The bottom width would be 550 feet and the slopes of the sides of the channel cut and the water sides of the levees would be 3 to 1. The sides of the channel would be protected from scour and undermining by a rock and rip- rap protection the sane as that shown on the cross section of Plate XX\''II. The levees would have top widths of 20 feet and land side slopes of 2 to 1. With a channel of the foregoing dimensions, the flood of 79,000 second- feet which might occur once in 250 years on the average with the Ouyamaca, El Capitan, San Vicente and Mission Gorge No. 2 reservoirs operated for conservation orJLy could be carried in the channel with a freeboard of 2g- feet on the levees remaining. The flood of 55,000 second-feet ".7hich might occur once in 100 years on the average with the same reservoirs in operation could be carried with a freeboard of about 5 feet on the levees. Mission Valley is crossed by two iiain highways, and new bridges would have to be constructed on both of these across the flood channel. In making the cost estimate, it was assumed that these bridges would be of the same type as the present Atlantic Street State Highway bridge but only thjee-fourths as wide. -250- A srraowhat detailod estimate of the cost of the foregoing; described channel is given in TaMe 55. This table shows the quantities of 77ork required and the unit and total costs for oach item. It is estimated from the County Assessor's valuations that the actual value of the lands and iir^provements, subject to inundation in Mission Valley do'ffnstream fron A'l.varado Canyon is $529,000. The value of the land required for the channel is es-'TjiT-ated to be $125,000. The present value of the land which vrould be protected is therefore only $404,000 as compared to $2,034,000 v/hich it 7:ould cost to give the protection. It, theroforu, does not appear that protection in Mission Valley is justified at present and that it would not he justified until such time as the protected land would increase almost six times in value, due to the protection or some other cause, or until the average annual damages would exceed the annual cost of the protection -.vorks. •251- TABLE 55 COST OF FLOOD CONTROL OHAMEL FOR SAN DIEGO RIVER THROTiCH I.ITSSIO:: VAI.LEY Alvarado Canyon to Morons Boulevard Capacity of channel (3-foot freeboard), 7P,000 second-feet. Channel and levees Excavation and levee fill 1,459,000 cu.yds. at Levee protection - Crushe-d rock 78,500 cu.yds. at - Rip-rap 249,000 cu.yds. st - CroT/n paving 22,800 cu.yds, at ."•0.18 2.50 2,50 262,620 196,250 622,500 57,000 1,138,370 Road crossings Murray Canyon crossing Earth fill Protection - Crushed rock - Rip-rap Paving 6th St. Extension Bridge Approaches - Fill - Paving Murphy Canyon Road Bridge Approaches - Cut and fill - Paving Right of way Land Clearing Fencing Culverts and levees Subtotal Administrative, en£'in''-ering and contingsncies Interest during constructiou Total cost 19,600 cu.yds. at 0.20 3,960 900 cu.yds. at 2.50 2,250 2,900 cu.yds. at 2.50 7,250 20,000 sq. ft. at 0.20 4,000 17,460 665 lin.ft. at 170.00 113,050 11,000 cu.yds. at 0.20 2,200 17,500 sq.ft. at .20 3,500 118,750 640 lin.ft. at 170.00 108,800 7,500 cu.yds. at 0.20 1,500 18,800 sq.ft. at 0.20 3,760 114,060 340 acres at 275,00 93,500 210 « at 150.00 31,500 250 n at 20.00 5,000 12 miles at 800.00 9,600 20,000 159,600 1,548,240 ngsncies 25^ 387,060 rate 98,300 ^2, 033, 600 -252- I^SPEmiX A RE3SKV0IR C- Tii^TION ON S.^IJ DIEGO RIVER The total safe yi(3lds and r.dditiona?. safe yields that m£.y be obtained from the opersticn of certain reservoirs, or combinations of reservoirs, in the San Diego River Basin are ^;.iven h\ Table 35 in C);<--pter VI of this re- iiort. A separate study was necessary to determine each of the safe yields shovm in that table. To t;.ive the details of each of those studies in this re- port would require a larfje amount of space. As an illastration of the method used, however, one detailed study is given in this appendix. This study is for the coordinated operation of the following reservoirs with approximately the capacities given: Cuyaxaaca, 11,600 acre-foet; El Gapitan, 115,900 acrt-feet; San Vicente, 174,500 acra-feet; and Mission Gorge No. 2, 29,200 acro-feet. The study was made for the period October, 1894, to October, 1933. The esti- mated monthly runoffs into the various res:;rvoirs are j^jven in Table A-1. The computations for the net dcp'tii of evaocratiou from the v/cter surfaces of the reservoirs are shown in Table A-2, fho monthly distribution of draft is shovm in Table A-3 anc" the details of the yield study are given in Table A-4. IV ater S upply of San DiOc^o River . The general mctjicds of estimating the water supply or ran-offs from San Diego County streamc are giv^n in Clitpter II. The run-offs at several points in the San Diego River Basin, which v/ere necessary for estimating in- flov: to the possible reservoir:;, were esti:uatod as follows: The run-off of the San Diego River above the Diverting Dam, excluding the inflow into Cuyamaca Reservoir, v;as used as a base for estimating the A-1 rurKfl^ at other points in the basin. Seasonal run-of'fs at these other points during periods of record, expressed in acru-feet per square mile, were plotted ar,£.inst the run-offs tt the Divertiuf?; Dam for the same seasons, curves of re- lationship were developed, and seasonal run-offs at the other points in the basin during periods of raissing records were estirriatcd from these curves by using the seasonal run-offs of the San Diepo River at the Divertinf-^ Dain, less the flow into Cuyamaca Reservoir, as indices. Estimates of the seasonal inflow into Cuyr.maca Reservoir covering the period from 1837 to 1892 were obtained from a report by t.he late ?I. N. Savage, Hydraulic Engineer, City of San Diego. Monthly estims^tes of the inflow from 1892 to 1919 were obtained from a report by John S. Longwell for the United States Bureau of Reclamation, f.nd from 1919 to 1932 they were obtained from data compiled by F. E. Green. The monthly inflow for the season 1932-33 was estimated from records obtc-.ined by the La Mesa, Lemon Grove and Spring Valley Irrigation District. From 1883 to 1887, the run-offs at the Cuyamaca Dam site were estimated from the rvm-offs of the San Diego Riv'er at the Diverting Dam, The run-offs of the San Diego River at the Diverting Dam were estimated excluding the inflows into Cuytunaca Reservoir. In all run-off and yield studies, vjhen the run-off of the San Diero River at the Diverting Dam is mentioned, it is understood that the inflov. into Cuyanaca Reservoir is not included un- less it is dcfinitc-ly shov.Ti thct the run-off is the total full, ni tural flow at the Dam. Records of diversions from the San Diefro River at the Diverting Dam and of waste over the dar.i are c.v:;.ilable from 1G98 to 1953. During a portion of this period, records were available from both thu La Mesa, Lemon Grove and Spring Valley Irrigation District and from the U. S. Geological Survey. In general, thu records from the district were used as thoy cov;-red the greater part of the period. To obtain the natural flow of the San Diego River at the A-2 Diverting Dam, it v^as necessary to add the W£. tt ever the dcun to thu diver- sions into the irrigation district's flume and to deduct that portion of the release from Cuyamaca Reservoir which reached the Diverting Dam, For the period prior to 1915, estimates made by C. H. Loo of the amounts of the Cuyamaca Reservoir releases which reached the Diverting Dam v;cre used. For the poriod from 1913 to 1933, an independent estimate of the losses from the Cuyamt.cc. Reservoir releases was made. During the greater part of this period, a record of run-off at the laouth of Boulder Creek was available. Deducting this run-off from that at the Diverting Dam gave the run-off from the San Diego Rivv^r above Boulder Creek. Thuse fi.^Aires indics.tod the periods during which there probably was no flov; from Boulder Creek below Cuyamaca Reservoir, Fortunat-ly, there viere no releases from Cuyanaoa Reservoir during periods of high run-off, and therefore the uncertainty of the amounts of loss from these releases was not introduced. For the period from 1887 to ]-898, the seasonal run-offs of the San Diego River at the Diverting Dam v;ere osti.'iated from . average indices of seasonal run-off as determined from the inflovjs into Cv.yamaca and Sweetwater reservoirs. For the period from inss t.o 1887, the seasonrl run-offs c.t the Divert- ing Drj3i -v.ere estimated from rainfall. Rainfall records covering this period are available at tvro stotiur.s, San Diego and Valley Center, Siact Valley C-ntor is at a higher elevation, its rainfe.ll is believed to be noro repre- sentative of rr.infall conditions on th.^ wctershn,d j.bove the Diverting Dam and its records war; selected for estimating the run-off at the dan. Paiollel records of rainfall at Valley Center and run-off at the Diverting Dam are availcbl^j from 1911 to 1924. In setting up a r-letion betv.'oon the two, the depth of seasonal run-off above the Diverting Dai'.i, in inches, was first plotted agf.inst the seasonal rainfall, in inches, ;.t Valley Center. Second .deductions A-3 of 1, l' end 2 inches, respectively, were raadc from each stcrm's rainfall at V£.ll^y C.ntor, end thu net scasjoncl rainfalls et Vclloy Center thus obtained were plotted against th^ run-off s at the Diverting Dam. Third, the foregoing not seasonal rr.inf; lis at Vr lley Center vjoi'c corrected by adding to each a porcontc-pe of the difference between the preceding season's gross and net rainfrlls, to allov; for secsom.! carry over fron {ground w-.ter in the run-off rt the Diverting Dcjn, and thesu corr^ctod :ict se- sonal rf..inf;-.lls v^^r... then ■•lotted c;:,ainst th^ run-off s. Curves v.'orc then drawn shov/ing the trends of each of the foregoing s^^ts cf plotted points ' nd the accuracy of each relationship was det.-;mined by riier .iurini, the .vur£.-> d-parturcs of the ^.lotted points froui the curve shovi'in.G the tr^nd. It v/as determined that a curve dravm by plotting corrected seasonal r. inirll at Vclley Coit^r obt.inod by deducting two inches from -ach storm rainfall end adding perc^nt>:.g.,s of the difference betwuen gross and net r-.dnfalls of the procedinc season varying uniformly from for a 10 inch difference to tv^enty percent for a 20-inch difference, ac.aiast the run-off et the Diverting Dam gave the best relationships* Such a curve w; s used for estimating the seasonal run-offs at the Diverting Dcm from 1883 to 1887. Run-off records of the South Fork ef the Sau Diego River near its mouth are available from 191?, to 1953, Hov.'cvcr, there are many periods of missing r.;cord, usually during times of high run-off. The full natural rxm- offs of the South Fork during periods of record v/ore obtained by adding the diversions by the La Musa, Lanon Grove and S-a'i]ig Valley Irrigation District to the waste. Both the monthly and seasontl full natural ruii-offs of the South Fork were plotted against the corresponding run-offs of tlie San Diego River at the Diverting Dfjn. A poor r^latiour.hip was ehovm by these points, probably due to inaccuracies in the South Fork run-off record. Hov;evi^r, it was necessary to establish a rel- tionship from v/hich run-offs in periods of A-4 missing record and prior to the period of recoi'd could be estinated. The sea- sonal inan-offs of the Sovith Fork, reduced to acie-feet per square mile, were therefore plotted against those of the Sc.n Diero River at the Diverting Dam and a curve v/as drawn to show the trend of tl.Gse points. By usinc; the run- offs at the Diverting Dam as indices, the run-offs of the South Fork during seasons of missing record were estimated from this curve. Estimates of the run-off of the San Diego River at the El Capitan dam site for the period February 1920 to September 1933 have been made by F. E. Green from measurements at that point and st other points on the river, and from records of flow at other points on the river taken by other agencies. These were used for this period. By deducting the waste at the Diverting Dam, and that from the South Fork, from the e.r;tir.iated I'un-off at El Capitan dam site, the inflow from the intermediate area between the South Fork, the Divert- ing dam and El Capitan dam site was obtained. Tho full natural run-off of the San Diego River at El Capitan dam site was obtained by adding the computed inflow from the interraediato area between it and the South Fork and the Di- verting Dam to the full nrtural run-off ct the Diver-'>;in,'^ Dam and to that of the South Fork. The sbasone.l full natural run-offs at the El Capitan dean site and those from tho intermediate area, expr:jssed in acre-feet p^r square mile, were plotted against the corresponding seasonal full natural run-offs at the Diverting Dam, and curves avorCf^int- these points mcto di&wn and adjusted so that the suiii of th. r^an-off 3 from above the Diverting Dam, from the South Fork, and from the intermediate area would equal the total run-off above El Capitan D?jii site. For the ooriod from 1'J].3 to 1920, thu ran-off from, the int..rmodiato ar^^a was e8tiri:iated from the run-off at the Div^^rting Dajr. and addt,d to this latter ru.n-off and that frem the South Fork to obtain the total run-off at El Capitan dam site. For the, period from 1S83 to 1912, the run-offs A-S- at El Capitan daro site v/ere estimated from those at Divertinc D-"-'^* *^<^ mn-offs from the area betv;een the Diverting Dan and El Capitan dcm site were obtained by subtracting the run-offs ::t the Diverting Dcjn from those at El Capitan dam site. From 1905 to 1915, the U, S. Geological Survey obtained records of the run-off of the San Diego River at Lakeside, a short distcnce below El Capitan dam site. During this period, the inflow from between the Diverting Dim and Lakeside was computed from the run-off records and this in turn wc.s divided into tv;o parts, that coning in above and that coming in below El Capitan dam site. If this division Indicated loo much in- flow from the small area between El Capitan dam site and Lakeside, the estimated inflov; above El Capitan dam site was increased so that the in- flows above and below El Capitjoi dan site wore in proportion to the drain- age areas. A negative inflow between El Capitan dam site and Lakeside indicated absorption in the gravels. Estimates and measurements of the run-off of Ss.n Vicente Creek at the dam site near Foster, for the period from 1919 to 1933 and the greater pert of 1914-15 season, made by various sgencies, v;ere used for these periods. The seasonal run-offs for these periods, expressed in acre-feet per square mile, were plotted agt inst the corresponding run-offs ::bove the Diverting Dan on San Diego River and a curve was dravm averaging the plotted points. For the periods of 1883 to 1914 and 1915 to 1919, the seasonal run-offs from San Vicente Creek were taken from this curve by using the run-off at the Diverting Dan for each season as the index for that from San Vicente Creek, No records of the run-off fron the area below El Capitan and San Vi- cente dcm sites and above Mission Gorge are available, but the seasonal run-offs were estimated in the following manner. The seasonal run-offs for each of the seasons from 1914-15 to 1916-17 and from 1919-20 to 1932-33 from above Cuyamaca A-6 Reservoir, above the Diverting Dan, above El Capitan dem sit-, above San Vicente dam site, and the inflow into Murray Reservoir, all expressed in acre-feet per square mile, wore plotted ag&inst the average elevations of their watersheds, curves were dravm averaging the plotted points for each season and the curves were extended downward to zero elevation. By entering these curves with the average elevation of its watershed as an index, the seasonal runoffs for the area bctvrcen El Capitan and San Vicente daiu sites and Mission Gorge were ob- tained for the seasons represented by the curves. These seasonal run-off s were then plotted ag&inst the corresponding ones from above the Diverting Dam and a curve was drawn averaging the plotted points* For the period from 1883 to 1914 and for the season 1917-18, the seasonal run-off s from the area between El Ca itan and San Vicente dam sitco and Mission Gorge wore obtained from this curve by using the run-offs from above the Diverting Dari as indices. The seasonal run-offs from this area were tected and in some cases adjusted by the follov/ing procedure. The valley of the San Diego River belov; the El Capitan and San Vicente dam sites and above Miseion Gorge was treated as an underground reservoir and studies of its operation were vnade in the same manner as for a surface reservoir. The run-offs at SI Capiten dean site, at San Vicente dam site, and from the area between thuso sites and Llission Gorge were tr^^ated as inflows, and the run-offs at Mission Gorge as outflows. In addition, there vicve useg from this underground reservoir caused by pumping by the City of San Diego and the La Mesa, Lemon Grove and Spring Valley Irrigation District, pump- ing for the irrigation of vcll-y lands, and natural use by willov/s. Records of the amounts purapcd by the city and by the district are availe.ble and were used. A field reconnaissance in 1934 indicat.-d that 2400 acres of valley lands were irrigated, A seasonal use of 2,700 ecre-feet for these lands was used. The area of v/illows was estimated to be 1,000 acres and the use as 2,64 acre- feet per acre per season. For the period after September 1928, the use by A-7 vdllov/s was discontinued as hor.vy pumping during the late dry soaaon had low- L^rcd the water tcble und killed the large treos. A monthly study of thu opera- tion of the underground basin was i.:adc covering the periods from July 1907 to September 1915 and from Jun. I'^IG to Scpte ibcr 19^33. During these periods, re- cords of the outflovj at Mission Gorge were available after 191£;, Prior to 1912, they wore estimated from the inflov: into the Sv;ectwatcr Rus^^rvoir. Dur- ing the periods covered by the study of the underground reservoir, the study indie; tod no large outflows in excess of those measured or estimated at Mission Gorge, showing that the run-offs and uses as estimated were probably correct. The seasonal full natural run-offs at Cuyronaca, the Diverting Dam, El Capitcn and Mission Gorge as estimated by the foregoing described methods are given in Table 7 in Chapter II, The monthly full natural run-offs at each of the reservoir dam sites and from the areas lying between these di.m sites are given in Table A-1, Evaporation from V/ater Surfaces of Reservoirs in the San Diego River Basin_. The methods of estim.ating the rates of evaporation and the annual and monthly gross and net evaporation losses from tho Cuyaraaca, El Capitan, San Vicente and Mission Gorge reservoirs hcvo been discussed in Chapter VI, The estimated gross evaporations for ^ach month of the year at each of the above reservoirs are listed in Table 33 oi' that chaptfr. In the dis- cussion of methods used it was statv,d that the net monthly depth of evapora- tion was obtained by deducting the depth of the rainfall on the reservoir surface during the month from the gross depth of evaporation estimated for that month. Since the rainfcll in any one month varies from year to year the net evaporation for that month will r:lso vary from year to y.^ar. In months k-6 of exceptionally heav^' rainfall the net ev:^poration may even become net-,f.tive indicj:;ting an increase in the storage due to rpinf£.ll on the reservoir surface. The estimated net depths of evaporation for each r.ionth during the period of tho yield study from the surfaces of Cuygunaca, El Capitan, Sen Vicente and Mission Gorge reservoirs are given in Table A-2, The evaporation in any raonth in acre-feet at the various reservoirs v;as obtained from the average areas of the reservoirs during that month LUltiolied by the corresponding net depth of evaporation. Neb Safe Yield of San Diego River throu.'-h Coorainated peration of CuypJTi aca, El Ca^'itan , San Vic eiite and Missi n _Goiv:':e_ _No . 2 R eservoirs. Table A-4 presents a portion of a detailed study of the coordinated operation of the Cuyamaca, El Capitan, San Vicente and Mission Gorge 2 reservoirs to obtain the maximum net safe yield from the San Diego River drainage basin above Mission Gorge. A summary of tr.is r^tudy iias been pre- sented in Table xl\. of Chapter VI of this report. The reasons i'or selection of the reservoir capacities used and a brief description of the methods used ha3 also been given in Chapter VI. The entire study covered the 50-year period from 1883 to 1933, However, only that portion included in the period 1894-1933 has been included in this tublc. As was explained in Chapter VI, tho estimates of run-off in the earlier years of the period 18S3-1933 vjere based on rainfall and cannot be considered as reliable as the estiioate of the later y^ars. For this TL-ascn tho analyses asoumed a required spill of about 20 per cent of the run-off for tho period 1883-1895 and the analyses were made using run-off groupings from December 1st to April 50th, Iviay 1st to May 51st, and from June 1st to Novtmb..r 50th rather than monthly run-cffs during this period. It will be noted that in tho detailed yield analysis the monthly run-offs used arc given to the nearest acre-foot. A-9 For t'is reason thoy do not correspond exactly to the i-un-offs pre- sented in Tcblc A-1, \;Kich wtre rounded to the no£»rec;t ten and adjusted to correspond to the seasonal run-offs presented in Table 7 oi" Chapter II, which v/erc rounded to thu nearest tcii for seasonal estimates which were based on actual records and to the nc;.rei;t hundred for seasonal estimates based on comparr.tive curves. In the net safe yield studies of coordinate reservoir operation shovm in Table A-4, the inflow into Cuyeaaca Reservoir was stored in; that reservoir until May Ist of each season and then r-,ljrsed as rapidly as possible to El Capitan Rusjrvoir if storage was available, or as fast as storage bec.jnc availabl.. An irritation dr-.,ft of 5,000 acre-feet was furnished at all times. This draft xvas obt:.inod from El C-'.'utcn Reservoir as long as the water was available in it and then from San Vicente Reservoir. No wcter was drawn from Mission Gorge reservoir for this purpose. Additional drafts for other uses v;ere drawn from Mission Gorgv. and El Gepitan res-^rvoirs, in order, until each was empty, and then the dr:.ft v/as takon from San Vicente reservoir. This nethod of draft v;ould reduce evaporation losses to a minimum by retaining w^.tur longest in the r--.s^rvoir with smallest evaporation losses, and results in ■■ grert.^r safu yield then ; ny other method of operation. The monthly distribution of the seasonal drafts used is shown in Table A-3, A- 10 I §f8§£2^§°°°° Q OOOQQOQC>000< to -J) F-Kio J OOOOOQOpOOOO fw 9'\X>J a • a * • *• 3** a to o -< o • •■5 m ^ P J -"I a 4l '^IS«SS£§ § SR|Sg^RS°°°° Q OOOQOggOOOO< OOOOOOQOOOOO g oooogosi I °°s8Sgfs^^ ^ \f\'~0 tf\ v^ r4 (Tt <7N Cn '^^SJ'^ J* fvi Kvt^ °°S&8&88' dl '8|g||S8S°- O QOOQOOOOOOOO O OOOOOOPOOOOO cu LntfSc\j «o 8 °°&RSSSS°°°° 1" ill O »• « » I lu&Mhmr^ sii«lilliiiiis liislshiidii IiiiiihiiiIi^ «rsmmmu - 1 3 9 s a* 'SS9S 68"' T! illJS "in |.. .. I -I -II \9 •I a • • k' a 6 i^S! i?^l 8 3a: §^ ij5 Kj GO cnu5 XtjS IP pH f^ h^ to fU ,H 'OpQOOQQOOO f>\f— OJ r^ J' (V J' P- tr. W r cr> J- ir\ K> 1- 'PQQC)OQC)OC>< -- _ Sqm ^f\K^^-^CT■CT^O -< ^ t. • • tN 1^ .s S,S&SSSSS2°' O p O^ f*M£ 2 <2 aP 29 o P 2 P o o o f^ *H rH 0** O^ O^ f^ fU f'sw'jjcijo'^oeorv o r^iH fvi Q OppopQOOOOQO 8 8 ooooooooooo tnj- f^vc cvj u^ »^ c\j to (U^D OJ O P OOOQOQQPPQOO a^ to f— O vfl f'N r*! Q W *i »^ to ^ tv r-o>3 fy to >^ ir« (\l r^ SQOQOOOOPOOO ^(Tlf'StOVX) Q CTiftl d 1-1 r^\^\0\0 W o t^f-t r 8 S85S<25S8S°°° r- r^ K^O (V \A to iTi n> 888 sasgjssss ■i ^^ to k\(\j K^vD «: «r-.f'\.-4 O Q O O O 8 SRSSS8SSS°°° ^ i^ tri f— ^ cv en « ^ ^ I ?l i«ii&sfss«^s 8|^si&»sr°° gOQQOOQpOOOOp r^ OJ C\» (Tn K\ o to K\ .M Q O O Q O O Q Q Q O p p Q rH o o c\j o ch r^ d »i^ f^ ftj pH p W p OOOOPOOOOOOO ^ irvS' VC ffv O r- 1^ "^ •-» •-• 8 02C20PP092P0 o o o o r^cu ^vo (\j f^i- !SR°' CM to •-( CM 8 &88S2S88S°' to invD J- «c ff- ^ o »— rH i*M^r-. CM Sooooopopooo eOrHiHir\.-Hft'»-*CTN rH^ rH^X, O O lf^■-< CM «0 i-l CM 8 0000QQOOOOOO incymrH^^ loa^^- lf\ K\ rH f^ rH CT> to jS- IfS vc r-» ^f^CM if\r- SQOOOQPOQOOOO r— CM (r\ Sj r— jt bd cm ^ ir^ O CM-U rH if>i2 *f ii? ^ i O IP. o^ CT\ ;tf ^ 8 Opp Q O < tC l^^ •'> OOOOpOOOOOOOQ r— 0^tf^ rH C> to »'^ J* -JJ rH to r^ CM OOOOppOpCDOOO ooopopoooooo > p o p o o 8 0000PPQQPC rH rH rH ir\ nj CM I»%\Z O to -H CM » inO W rH VO b c • to • ^ A II ViOOSB«jePi«33P*0 TOOO»a«j«p.jB03P» rH CM CM f^ OOOOPOOOOOOO to b • e i m to e ^ ^ I •a A?88 j 18 o «ouo»aejBO.<9po»o wu^S^JJQ-a^^SJS^ eJ rHoe!0'^fc3i88 OOOOOOOOOOOO § °°°°ll;& 9 ill OOOOOOOOOOOOO ^®°S&i2St2°°°' I °SRa||SR|||Sg °°°S§f&&^»S 8 °»g2S,g8S,82&' OOOOOOOOOOOO J °°°SRR88°°°° OOOOOOOOOOOO I °2S5|5S8S8S°8 °°°2R||X» 8 °°22SS!J!5S!.88' 4 •-. o ^ ruv2 K>^ I °°°§SS2^°°°°S °»8tpf|»|gSg °°°S^gp.SJ8 § °*S8gf.§R»»R° 'Hi OOOOOOOOOOOO & "oogS^S^"""' I °S*.2S|.|.g|g2S,< I °°°8«SIr|S2°| °°2Sg§pgSR B ! 3 :: M OOOOOOOOOOOO OOOQO 0&0 o o o < ^ ^ r4 ^ S °82S§e8S^°S°SR °°°R|,a8°»°°°§ °RSS|f»282° hi 300JI ■•J oij3'3 gS -SWAGE'S ^fl fl '■i'-UV^ii^lP ^^-'Ml^si^^lP ^si|||||j|g-||| |||||l||ji5i|2 ^ll|il||si^^l|| isalslalllll* ssfi«^s3*3IHI« 2s««l«3«3lllse 5s«a4«l*J45S^« Sg£a4fi:S*a^.-,-." ■ 0«'0^lll 'iff? •3 .t-SSIiE-g? •-all J 1 - 1 I .16 l1Sa| 82»5. SI'S s^3 =8|||g°°°SS' OOOOOOOOOOOO 8 °°8R88S5S' OOOOOOOOOOOO °R 8 °°8&8S^S2R°*=*'=*' lis r'S O J »N_ • • ^. It i ^^iit,b I RtlSt? -I. <>~>U>4 3R1S l588lgSS&«ae2| 'lUi& O O O O 8 °°S3SiS°°°°°& """SSS^" OOOOOQOQOOOO oooopOoooooo ^ °^SIS o 2{> o oo o CU r4 8 °°fgggS o o oo o 8 oo««S».»°**°* 2 I-) tf\U> M %%,9S oooooqBqoooo I OOOOPQOOOOOO 'S^RS 3 ^fl§g|^§§5§S§ SSigSfsSl^g & H&^Hpg*!?? 2°s25^segs^|S| l*gHIS&«S5§| 0«« W^ M<^ $■ '"S' fi § 8»gs*S£S*S&S» 8 SSSSS8Se«°°S SI&SS2' g^ S°°8Rf[R|R»»2 I °°S5^||SS''°8 I 'a°B ^ f^K\«l ^ s8rtg?3psS§8| °°S88g|RSg8S I SS&»gg|g&' I sM S°SSS8R°8Sf II] fill UishlUnUi iuuzhutm shunUmn ^Ikuihmm - 8 a 2 2b a* OOOOQpQQOOOOp 'R&8» ooooooooooooo UN w tr» to o ir» cj - • -» °°°°8»S,i» OO o o O 8 °°°°&R88S°°° — tf\ftJ Ovo 8 °°S885»S»°° ie\ fu n vo «0 Ai t^ •-« 8 °°°SJR»°°°°° I 3 -la s'1 - oooooooooooo °°°°^g|gg8'^ Q oooooooooooo O CU § °°i^s§sr' o oooooooooooo S 3 i^»--^ o o O O O p O Q o o o o p ooo >&9fi900QQO 8Si|ssaas!,asss v\trA2^^i> O i^ ir\ nj to VD ^ CM M ir>i-« M fNf^ s K^ifaisei^i ^ i-t in»^i-» ' oooooppooooo 'S8J 8 °°°RSS8aR£S,8 8QOQOOOQQOOO< r> fw •-« P% O ^o r^ iH ir\ K\ ni > 1-4 1-4 o (TttU ^ #4 K\^ .4 a ? C OOOOOOOOOOOO §§*' °°°SSS38SS,S; ir>rr»p4 2& SSSS»Sg8»5SS nj 9Mrt ^ irt^ »^ r^ r— ID a\3 5 ^Sg§£iSfl^S ^sR^sls^^Rli «0 K\ r4 •^'^irtCU tH f\i 10 r^r^vo (u c\> ^^ii OOOOOOOOOOOO - si RSS' a, °°o£»&S«S8»8S SfRg82»R8S!,8S£ oj O CM ■) \A ^4 v^\0 ^ ^- f-3 a^ ^S£«^&&§^IS SSslggglH^sf (M K> ru n^ ^ r4 Hvo c\t irvirsnj m •-« «^^ CU ^ 8 oooooooooooo '&a °°°g85S22RS; K °8»8,e»»&g2f° 8 °°8&»gS8S<&S.' j> t»- F- io K ^t» CU § P«S^g&fg2°°88 • H I . -a O • lO ~ Jllliif?. •^1' ll illhUi^kttM it •Z8 if\jT ■^ til Kn: ^ JT ^ K m M vA 2«B CM g sjRg^|£§&»s||§ »»sni|||IS^ g*^ISfmfS2 J1 3^" OOOOOOOOOOOOQ OOOOOQOOOOOO g o o o oo 2 o c oo o o o o oo o o o o o o oooooQQ^^^^^ >»»» |S2 ■I a • I OOOOOOOOOOOOQ OOOOOQOOOOOO '8g8' Q OOOOOOQOC oo OO ooooo o o o o oo ^POOPQQQOO' Ox^ le ^. r\j SS2SS8SSSS. Sa8»S&S8g2S° so »^»-. (M S 5S,»5SS£2S»2S S^ fc2S822SS,8!^S.S o P. vo ^ w CN CM -3 "^tC j» "^ ^ »2g8»5^&2°°' 8 °£&S»8S258°° gOppOQOOOpOOi o^ a^<^^^->J» ft. -^cy> ^-< O^ ^ CW »^1S -^O (M "^^ ^ »— %0 t^ »— ^ CM - S2S^8e58»SS8S, »^K\ir\^^^-Otf^*^'* cw ^ SSS»8»8»RRS°S S3SSSS5S,S!,32SS »9,S!,8SvSSR»»2a ^%£ O H ^~ (O ^. H '- -S I i ? ? -^ - 5SUl-ailllll lllllfilillllia si«lln.'llll^« slial2l*llU% "- 8 §§l8ISSs*^'l '2&^liSI§^fS^iJ O «]v£ ^u r^ ^aiigiissji^l liiiigss^a^. g^lip.a.s_ReR^^ (y ^ o^ ir\sO * Jill' icBjJ oooQpogi^ooooo VO »> i»> OOOOOOOQPC tc^'fto^ 8 °°°SRiSS5S°' ^ ^\ ^rt ff\ ITi C^ C\i O OOpPPOQOOOO* CM CU r4 OOOOOOpOCOOO S5 § I*' --I OOOQQOQOOOOO 'fl|S^ 8 °°°2S»8S^5°°' -- J- ft.' « (T* '^ ^ J- ft.' « (T* '' — io Pg .-• "^ C)09SOfi9^^o^^ § °°ltlHs OOOOOQOOOOOO i I ill CM CU Mr\ Ad r4 ir\ r4 CM i SRRS2SStic.£S * ^^ Pj tr. f^ "^ .^"^ (TV «> p ffv ^^ ^H CM r4 At CM I gS§2f|fR||§SR Sig2Jf228|^2 9OCOS2C>0OOQPQ t ^:t^ f^w oQpogoooQooo 'S,8£8£8e5 r-i-i K\?\(M § 285§^||g|g-52 O OOOQOOOgOgOO 8 SSSS8g8£8S8S SS^258£2&25SS 4 CM ^ ■-• B ^ °»825S,S!,85»,SSS R2R££8822SS!^ «-< ft W ^ r— CM ffi CM iTt ^ K\i-( »^C\^ iTk'H.* »^ SSRgi2SS!.£»88R ?4*E8,?Sli§,8g gS^SII*Ji*S2 ;» ir\' SB 2 sll|9ijHI3lll b b 10 b • • >t t Zi m £ ja C t S^S«P.»P»§g8 »s§S^|BF32 8§t*|geg588e cw •-< u^■-•^A » 8esij?»»s8R8es8 ^ 9% tf\ftl A< *^ OOOOQOPOOOOO « I • A. S HI a OOOOOPOQOOOO I °°°8°|Rg OOOOOQQQOOOO g "gSiSS^S"""" 8 °°Sfg&g«' OOOOQQQOOOOO '»IS O O OO p O Q Qfi *^ *^ O O 8°fRg= O OOO OQ O Q O O O O O § °° ««£*«»= p4 f^ ^ to ^4^- ^ nj fH v2 ^A r^ I (\J f\J ^ ■-• (VI e e I ,U SSSRS^SSRSSRSS 88R8§&R88e»S S SgS^§f§§2S»SSS 28^g^g^2|»8S| 8»SSRS||°|Reg 8«5 « q a l4 'gmmmit 3 AI!lil|tK|§||3 Asiiil|tsS--|l3 ^|n|||cK|^-||3 t, ss«al«l*lllll« n&i&ls.isis.s.li» ssjia4«3*Jl4slfi § 5 I- s "J E •t a* lias 858-; I a llgg|£lls^Sg|g Sl§&^ttl»°-S|l SRe||§J»§8SS|8 oooooooooooo ooooopoooooo o o o o o o oo o o o o o o oooooooooooo oooooooooooo >s»s 8 °«o°§SRSS°°° o o oo o p oooooooooooo si « iH AJ ftl ^ oooooooooooo 5 C § X 5 *• S *■ *^ R 2Se8RRRS^|R°52 8RRSSR&R88SS2 i-t t^r- QSQOOpggoQpo &8R8SR82SJSS r^ w4 li tV -* 8 <^j» I 88»8S£g^»2°S o OO e «§gg£§«»«sS SS»S|2^8» op^lP^^Sffi^^^^ t^ r-'f^Jt ^ ^ a o >> §^^gg||SSIS|S §l|2f&|SSS^°5|| §2||g8|g&RSSJ| 8&|gS^|p2|^ j« ^1^ (y\^ Ai g |8|§SHI»f«l a • q cf • 3 q w " 9 * ** ** 3 «• I R8S,|5UgR2°° S 85RS28SSvS O O O O (\1 ^ IB cr\^ M =F « q a .8 'a »§§2^M°S^sl^ ISR8«&I&«»°5| SS2R|||S2»gS| SS|2p£S§g§S| §S8gggS22t^| S ^ t. • V .1 I ilJllllliHll 9 fi X» C 4 *< I LOSS tK iviPoitTicn mm mannoiiia on am Dmo niTn 3AS TICIKTT RISBnoIl) AHB IL CtPITUI KISniTOllI 1894- 1S95 1B95-1B98 1896-1897 llontb Oroaa dapth RalnTaU Nat Oaptli RUnfall Nat dapth IWafall , Nat daptb or on(l] of on or on of evaporation raaerrolr BTaporatlcn raaarfolr anporatlon raaarroir aTBporatlon in Inc^aa in Inctiaa In i.iQhaa In tncaaa In i noaaa in Inoliaa in Inohea October 5.10 6.10 6.10 2.77 8.33 Not tab «r 3.80 3.60 1.60 2.u0 1.14 2.66 D«o«ab«r e.3S .6.04 -3.69 0.3« 1.79 3.31 -0.96 TsmiAry 2.eo U.29 -10.09 2.81 -0.61 4.87 -a.67 f«bruAiT 3.05 1.08 1.97 0.14 2.91 6.60 -3.BS Uarsb 4.50 2.19 2.31 4.99 -0.09 3.44 1.08 April 4.«3 0.74 4.19 0.8« 4.07 4.93 !l.y 8.17 0.62 0.55 0.20 5.97 0.19 5.96 Jun« 7.36 7.38 7.36 7.36 July a. 33 C 8.83 0.14 8.89 8.03 Augujt a. 04 8.04 6.04 6.04 3«?t«iiftr 5.06 3.65 6.6S 6.86 ToUla 43. lO 22.96 40.04 U.IO 51.90 22.32 40.66 1897-1898 1896-1899 1899-1900 Oetobsp b.lO 1.94 3.18 5.10 5.10 llOTsiixr 3.80 3.80 3.30 3.80 Lwov^bor 2.35 1.08 1.29 1.66 0.69 1.00 1.35 Jaauary 2.20 2.51 -0.31 3.34 - 1.64 2.99 •0.79 ."•biMU-y 3.0S 0.77 2.28 1.37 1.68 3.09 :;arcb -..50 1.72 2.78 1.93 2.57 0.96 3.64 ^rll i.93 0.51 4.42 0.24 4.89 2.06 2.67 jy 0.17 1.65 4.52 1.6S 4.58 Jun0 7.38 7.38 0.85 7.33 July 8.83 8.83 8.83 8.S3 iuffiat 8.04 8.04 6.04 8.04 Sjpt6:i)tT 0.65 8.65 6.65 Tslsla 03.00 10.18 52.84 9.9« 53 .81 8.08 64.34 1900-1901 1901-1902 1902-1903 Ocwb«r 5.10 0.15 4.95 5.10 '6.J5 4.75 - Movo30«r J. 80 4.06 -0.28 0.40 3.40 1.95 1.85 Oocasoor 2.35 2.35 0.05 2.30 2.21 0.14 Jan .ury 2.20 2.88 -0.68 3.19 -0.99 1.76 0.42 yobi-uaiv 3.05 8.06 -5.03 2.26 0.79 4.06 -1.03 Ubroli 4.50 1.20 3.30 4.33 0.17 2.03 2.47 i .11 •..93 0.80 4.33 0.85 4.06 1.45 3. 46 Ifay .J. 17 0.83 5.54 0.08 8.U 0.08 6.U Juna 7.38 7.38 7.36 7.36 JvOy 8.83 8.63 0.36 6.47 B.S3 AU/Mat 8.04 ! IJ 0'.04 8.04 3.04 Jjtjt tiner 6.05 ,0 .M.uO" 17.02 6.85 8.65 0.14 6.51 -1^3 45.38 11.50 51.50 11.05 48.95 M 03-1904 1904-1905 1905-1906 Cc;ob6r 5.10 0.17 4.93 0.52 4.63 0.07 5.03 .tovft.oor 3.80 3.60 3.36 0.42 iwsiiijar 2.35 2.35 2.04 0.31 1.15 1.20 ^Quary 0.30 1.90 4.07 -1.87 1.98 I'abnjary 3.05 2.87 0.18 9.81 -6.56 4.43 -1.38 fbtch *.50 3.65 O.SS 5.76 -1.26 8.66 •4. If sr^r.l 4.d3 C.40 4.53 0.44 4.49 1.69 3.34 IW 8.17 0.24 5.93 1.32 1 4.35 1.30 4.67 V.38 7.38 7.36 0.05 7.33 .'Uly 8.83 6.83 8.63 8.83 j;_'.£t 6.04 8.04 S.04 0.25 7.79 Sb|>taaDar 6.05 8.65 0.81 5.64 0.49 6.18 totals S3. a; 7.83 55.37 24.57 38.43 23.35 39.66 1906-1907 1907-1906 1908-1909 Oc:oiar 5.10 0.05 5.05 1.92 S.13 1.20 1 3.50- ■ ■■ iiOT-j .twp 3.30 1.90 1.34 1.16 2.62 0.30 3.x oaca .Jar 2.35 S.'JO -3.63 0.71 1.84 0.69 1.06 January ;.20 3.39 -3.19 4.16 -1.96 •..17 -9.97 'flbriit ry 3.C5 l.oJ 1.52 4.73 -1.38 •>.4;^ -1.37 Mt 4.5C 3.41 1.09 2.11 2.39 3.36 1.14 a; ■ 4.93 0.62 4.31 1.36 3.65 0.22 ft.. J. 17 0.33 6.94 0.47 1 5.70 U.05 8.12 a 7.3b 0.43 6.95 1 7.33 a 7.36 c-.'J3 .1.83 ti.83 . .04 e.Q4 0.67 7.37 0.89 7.16 .}ar 0,05 6.85 0.64 6.01 -.ala 83.x 19.80 43.40 le.so 4:. SO 1909-1910 1910-19U 1911-1918 ■•.Mjr 5.11. 5.10 0.60 4.30 0.30 4.60 3.70 0.51 1.87 3.05 |ifC',.i3or 3.80 3.35 0.26 1.37 2.43 0.10 Ca-.j-.Jor- 2.35 0.58 -4.21 0.68 1.69 1.84 ^Liv.ii.y 2.20 2.79 -0.59 4.36 -2.13 0.53 l.\'i..r/ a. 05 0..,7 2. IB 4.20 -1.15 n.t. 4.;jO ;:.-.8 2.02 1.37 3.13 9.75 1.83 4.93 C.33 4.00 1.29 3.04 Kay Juae 8.17 7.38 6.17 7.38 6.17 7.36 1.67 0.50 6.68 8.79 7.41 6.65 Julj- u.as o.a e.52 8.83 0.04 .Ui ^t 8.04 0.88 C.04 6.37 G.12 8.04 8.53 0.83 •-all 63.CC J 17.17 45.33 14.19 48.61 IB. 48 44.64 {!) October 1894 - Sop(enb«r 1B9Q, 03 per cent of ralnTall at Talle7 Canter. October 1S99 - Septesber 10O3, raiufhU at CbocoUte 191i-1913 1913 -19U 1914-1913 I.U>ntll Oroaa depth Raln-'all Nat depth Rainfall :ihi daptb .'Xih^all Net depth of on of on of on of eTaporntlQB raaerrcir avapcratloc raaerrolr eToporetlo* reaerrol r eraporatlon in mcfiea in inoiiaa in incma in inohea in Inohea In Inanea in iniihea Ootobar 3.10 1.05 i.tt O.H 5.0s l.W 4.ur Jlovflcibar 3.80 0.60 3.0O 3.13 0.67 1.22 8.0C Daoarbar 8.30 2.39 1.88 0.49 3.07 -0.72 January 2.20 2.38 -0.18 5.60 -3.30 6.61 -4.31 Fabnjary 3.05 5.03 -1.96 5.28 -8.17 7.68 -4.51 Uarab 4.50 1.43 3.07 0.97 3.93 1.49 3.09 April 4.9S 0.45 4.44 2.47 2.46 J.89 1.04 May 5.17 0.36 5.G1 0.20 9.97 2.80 3.97 Jun* 7.38 0.22 7.18 0.17 7. a 7.36 July 0.83 0.05 3.78 0.33 8.63 August 0.04 0.12 7.92 6.04 1.37 6.67 3ai.t«nb« 6.65 6.85 0.08 6.69 6.86 Total a 83.00 11.93 SI. 67 19.88 4...-.' aa.sB-- 34. H 1915-1916 1018- 917 1917 1916 4.16 i.l6 1.92 S.B 6 5.10 KoTaiAar 3.80 0.99 2.81 0.06 S.79 0.43 3.32 8.35 3.64 -1.29 3.17 -e.a< 2.36 Januaiy 2.80 19.81 -17.51 5.03 -(.88 8.83 -0.43 Febniarv 3.05 1.90 1.15 4.36 -1.30 3.03 -0.03 March 4.50 2.17 0.72 3.7a 7.28 -2.78 April 4.93 0.38 4.61 2.55 1.38 4.93 8.17 0.28 5,95 1.36 4.81 0.03 6.14 7.36 7.x 7.33 0.00 7.35 July 8.83 0.19 B.I,.. 6.83 0.10 a. 73 Auguat 8.04 e.U 8.04 0.70 7.34 Septombar 6.65 6.36 8.65 6.86 Tot ala 63. CO 86.70 31.30 14.65 43.96 14.87 48.73 191B-191t 1919-1980 1980-19a Octobor 5.10 1.07 4.03 1.16 3.98 0.8]. 4.49 NOTaabar 3.80 8.U 1,69 1.43 2.37 0.09 Daoenbar 8.35 8.13 0.22 1.48 0.93 1.09 January 8.80 0.19 2,01 0.66 1.58 8.13 Fabruary 3.0 4.87 -1.82 4.76 -1.70 1.10 3.81 Uarcb 4.60 3.18 1.38 6.13 -1.85 1.89 April 4.93 1.05 3.66 0.84 4.89 0.19 Uay 6.17 0.07 6.10 0.13 6.04 3. a 7.36 7.36 7.36 a. 83 = .00 8.37 July 8.83 6.83 8.33 Auguat 8.04 8.04 3.04 0.04 6.86 0.46 6.20 0.08 ., 4.» o,se TQlala 83.00 14.48 48.64 18.40 19a -1922 19eS-1923 1983-1984 Ootobar 5.10 1.54 3.56 U.55 4.JS O.K -.72 Novanber 3.60 0.26 3.64 1.44 2.35 0.43 3.37 Daoanbor 2.36 9.44 -7.09 3.12 -0.77 2.09 0.26 January 2.20 4.63 ->,43 1.91 0.89 0.60 1.60 Fabruary 3.05 3.49 -0.44 1.55 1.60 3.09 Mar oh 4.60 3.83 1.22 1.39 3.U 4.18 0.30 April 4.93 1.86 3.66 8.12 2.61 8.44 2.49 Uay 6.17 0.53 6.64 6.17 6.17 Juna 7.36 7.38 0.18 7.26 - '.38 July 8.33 0.04 8.79 3.33 \. 3.83 Auguat 8.04 0.08 8.02 8.04 ^ O.U4 3a£tflBibar 6.65 6.66 0.13 8.58 A-rt.*! — iaau . 83.00 38.58 12.3J 5i.i1 10.64 19U -1988 1925- 1988 1926-1927 October 5,10 0.51 4.59 4.63 0.47 c.a 4.33 .:oT amber 3.80 0.71 3.09 1.27 8.63 1.14 2.06 jooanber 8.39 2.93 -0.63 1.64 0.71 4.64 -2.29 January 8.80 0.40 1.80 1.46 0.76 V.98 1.28 "ebmery 3.09 0.96 8.10 8,86 0.39 14.38 -11.87 : aroh 4.50 1.54 8.96 0,64 3.96 3.72 U.7B Ajrll 4.93 3.38 1.61 7,89 -2,98 1.67 3.26 i]ay 6.17 6.17 0.09 8,11 6,17 June 7.33 1.08 6.38 7,36 0.12 v,io July 8.63 0.63 8,83 o,::3 Au0iat 8.04 3.04 6,04 0,04 Saptnber 6.66 6.65 8,66 6.66 Totala 63.00 li.4S 51.57 80.10 48,90 26.47 3S.C3 1987 -19» 1986- 1989 1989-1930 Ootober 5.10 2.78 2.38 6.J8 4,75 1 3.10 NoTaabar 3.80 1.20 8.80 1,58 2.22 3.30 Oeo^ar 8.39 3.87 -1.68 8.81 0.14 8.35 January 8.20 0.77 1.43 2.39 -0.19 6.91 -3.71 February 3.09 1.63 1.88 3.09 -0.04 1.31 1,74 ..iroh 4.50 0.96 3.64 2.58 1.94 4. 02 0,46 April 4.93 0,14 4.79 1.51 3.48 0,46 4,47 Hay 6.17 0.47 5.70 6.17 4,33 1,04 June 7.36 7.36 7.33 . ti 7.36 July 8.33 8.83 S.83 ^.63 Au0iat 6.04 3.04 b.04 8.U4 Septflnbar 8.69 6.65 0.16 0.49 6.66 lotala 63.00 11.98 51.04 13.85 49,15 U.03 46.97 1930-1931 1931- 1932 1932-1933 October 5.10 0.3." ; ■..72 0.43 4.67 l,li . .;. Not saber 3.60 8.08 1.74 2,99 0.36 O.30 Oaaember 2.35 8.39 4.38 -2.01 3,68 -1.51 January 8.80 8.56 -0.39 1.88 0.52 4.81 -8.41 Fabniary 3.05 4.71 -1.86 8.60 -3.35 0,13 a.9S :jarcJi 4.50 0.04 4.46 0.18 4.36 :,S4 4.86 .prll 4.93 8.84 2.29 0.39 4.54 2,71 8.82 Uiy 0.17 0.98 5.86 6.17 1.22 4.96 June 7.36 7.38 0.07 7.31 0.03 7.35 July 8,83 8.63 4. .S3 6.63 Auguat 8.04 0.15 7.89 C.04 8.04 aaptanbar 6.65 «.«5 rt.A^ 0.65 To tela 63.00 l?.-.«... . . iS..J6 . 1J.60 49.04 USLI A-S, IContlnuadl LOSS IN IHtrUHjaiOK not USIR^i^ilUi uN 3111 ilMiO Rim lassicM Mcoi ao. t aisanoiii 18»4-18«5 1893-1696 1896-1S97 ■lunC ^a« daptb IfclsfaU Sat a.ftb Hal stall Hat dapth .■talnfall Hat dastb of ood) of ce of oa of iTBporatlcn paearrolr anpo ration raaarrolr aTaporatloD raaarrol r OTaporatloj ta Inc'^sa lA la:b«4 la Incbaa In ic^aa In lacSoa la inchaa Oewb«r 4.3S 4.as 4. 85 1.37 3.45- ItoTaAu' 3.6£ 3.62 3.62 1.39 2.83 D«e*A«r 2.S4 2.12 O.lt 3.16 -0.98 3.09 -0.85 Jaaiary 2.og U.32 -9.23 1.60 0.29 4.44 -2.35 r*bzu0ZT 1.91 1.06 l.as 0.02 2.89 3.89 -0.93 Ihreii 4.29 1.62 2.6? 4.10 0.19 2.17 >.U l;rU 4.70 O.IT 4.33 0.35 4.3S 0.02 4.66 tky 5.86 O.IS s.ro 0.04 5.S4 0.17 5.71 J«ii» 7.0S 7.01 u.Ol 7.01 7.02 Julj 3.41 8.41 8.41 0.01 8.40 l^S^at r.M 7.66 0.18 7.48 7.9« 5«rta^flr 6.33 6.33 6.33 TotiJj 40. M 16.47 43. S3 9.69 50.31 16.52 43.4S lA97-lBgS ia9e -lfl»9 1899-1900 Oetobor 4.85 l.M 3.S! u 4.B5 U.57 (.18 ■OT«at 7.0t 0.03 6.»« 0.32 6.50 0.19 6.63 J41y e.ii 8.41 S.U 8.41 ia^uat 7.M .7.66 7.66 7.66 Sn-.^Mr 8.33 CIO 6.23 6.33 6.33 ^■•-fi'f iCi.eA ii.Bi 5«.07 B.M 51.95 1900-1901 1901 -i90a I90a-i«as OctoMr 4. S3 0.4O 4.45 0.S2 4.53 0.10 4.63 BoT*;l>*r 3. Si 2.61 1.01 0.28 3.34 1.73 1.89 DMBber s.ai 2.24 0.43 1.81 2.a U.03 JaBuaiT S.M 1.89 0.20 2.88 -0.19 0.84 1.25 rBbroazT e.91 2.6« 0.2S 2.49 0.42 2.97 -o.os Hsrcb 4.29 2.57 1.72 2.81 1.48 1.33 2.96 Ipnl 4.70 0.69 4.01 0.33 4.57 1.29 5.41 Ik7 S.SB 0.67 5.21 C.04 5.84 0.14 -5.74 JUM 7.0« 0.11 6.91 7.02 Jttly 8.41 0.10 a. 31 0.75 7.66 8.41 *■«■•< 7.M o.u 7.55 L 7.66 7.69 ST 6.33 6.33 S.33 80.00 Ui^ 4«.10 O 7^ W.JH7 in. 71 4S.SQ 1903-1901 1904 -1903 1905-1909 ■tC*»T 4.95 o.a> 4.65 0.27 4.58 0.25 4.90 Tjbar 3.62 3 62 3.62 4.39 -1.27 J«eecaer S.Zt 0.10 . .14 2,73 -0.49 0,55 1.99 JaajaTT 2.09 0.17 1.92 2.67 -0.58 l.X 0.89 ?9bniar7 8.91 2.19 0.72 9,22 -9.31 2.13 0.78 Ikreb 4.29 2.66 1.63 4.23 o.ot 9.59 -2.87 If 111 4.70 0.10 4.60 0.3« 4.54 1.66 3.04 »)r 3.88 0.29 5.59 l.OB 4.86 0.73 5.15 Jtua 7.02 7.02 7.02 0.04 9.96 Julor 8.41 8.41 0.03 8.36 8.41 insist 7.66 7.66 0.01 7.65 0.13 7.53 SsDtsi^sr 5.33 6.33 C.57 5.76 0.30 6.(M TDt«lj 90.00 6.71 54.29 ti.n 33.89 18.44 41.56 190»-1907 1907 -1908 1908-1909 Cwtob«r 4.85 4.33 2.10 2.75 0.59 4.89 lonabu 3.62 1.52 2.10 0.62 3.00 0.84 2.78 Decaibw 2.24 4.14 -1.90 0.57 1.67 1.19 1.05 Jamiary 2.09 4.35 ..2.26 4.5S -2.49 5.31 -5.28 Tebiuary 2.91 0.85 2.06 3.39 -0.48 2.83 0.06 Ikrch 4.29 3.06 1.23 1.34 2.95 3.3T 0.92 ^11 4.70 0.44 4.26 0.69 4.01 4.70 !I>T s,ae 0.20 5.6S 0.23 5.63 5.68 J^UB 7.02 0.2S 6.77 7.02 7.02 J>ll7 8.41 S.U 0.16 8.25 8.41 In^iat 7.66 7.66 0.89 6.77 0.15 7.51 3«;:i:l«r 6.33 6.33 6.01 6.33 ::•*!• 60.00 14.81 43.19 IS. 11 14.28 45.72 1909-1910 1910 -19U 191 1-1912 Octoi«r 4.85 4.85 0.94 3.91 0,£ 4.57 ::o7aa)«r 3.62 2.87 0.75 o.as 2.74 3.92 ::«e«aber 2.24 4.75 -2.51 0.33 1.91 1,59 0.93 2.09 2.72 -0.93 4.74 -2.95 0,50 1.59 ?«bniary 2.91 0.35 2.56 4.0O -1.09 2.91 Ifcrcii 4.29 z.a. 2.06 1.30 2.99 7.80 -3.51 A;rU 4.70 0.24 4.46 1.07 3.63 2.42 2. as */ 5.88 5.86 5.86 1.29 4.59 Jilna 7.02 7.02 7.02 0.7O 9.32 July 8.41 0.34 8.07 0.06 8.35 8.41 Augiat 7.« 7.66 7.96 0.32 7.34 3«Dt«:t9r e.33 C.15 6.18 0.4« 5.87 9. 33 Totala 6C.0O 13.63 46.37 13.78 46.22 14.90 45.10 October 1554 - 3ec«:l>er 1895, rainfall at il Cejcn City publlabsd In n.a,C.ia. ■fttor ai;;ply Paper 446; Joauary 1996 - I>oe€cb«r 1898, rolnfRil at U, iS. -oat.ier -Xixaeu Station in 3aa DlBgo aaltipliod by 1,417; Janiiary 1899 - 3e;tacbar 1933, raioTall at ^ Cajon publls^d by i.. S. Voathar Buroau. 1912-1913 1913-1914 1914-1913 ■oatk Jroaa daptb fUnfaU Rat 9a; tk Mlafall Hat 6aptb Raiofall Xat daptk of OB of OB of OB of traporatloa raaarrolr aTaporatlsa raaarrolr aTaporatloa raaarrol r arapora'.lco Id Ine^aa la Inctaa la Inebaa la Incbaa la laobaa Octobar 4.95 0.77 4.06 0.08 4.83 -TBS — 1 3.76 HOTICOOT 3.92 0.79 2.69 2.63 0.79 1.35 8.27 Daesbar 2.24 0.05 2.19 1.03 1.21 2.63 -0.91 Jaajarr 2.09 1.50 -.59 4,56 -2.47 8.49 -4.40 rabruaiT 2.91 3.10 -0.19 4,00 -1.09 4.22 -1.31 Uarob 4.29 1.09 3.20 0,60 S.99 1.33 2.99 April 4.70 0.19 4.51 1,83 3.45 8.a« 1.64 Har 5.66 0.16 3.72 0,27 5.91 1.42 4.49 Juaa 7.08 0.10 6.92 0,19 9.89 7.08 lul. 6.41 0.20 8.21 8.41 8.41 Au«uat 7.66 0.23 7.43 7.66 SoBtmbar 6.33 «.2> 5.33 Totala 60.00 8.15 51.63 14.62 _43J£ 21.51 38.39 1915-1916 1919-1317 1917-1916 Octob« 4.85 4.35 1,57 3.86 0.O4 i.m HotattiaT 3.62 1.28 8.3« 3.92 O.U 3.41 Daeaobar 8.24 3.47 -1.23 8.U 0.13 2.24 Jaaua;7 8.09 16.98 -14.59 4.41 -2.32 1.44 0.93 jabruaxf 8.91 1.57 1.34 8.25 0.69 2.29 0.92 Uareb 4.29 1.27 3.02 0.36 3.91 9.36 -2.(9 AprU 4.70 0.15 4.55 1.39 3.31 4.70 IfaT 3.66 0.12 5.76 0.97 3.21 0.09 5.82 Jim a 7.02 7.02 7.02 7.02 JUlj 8.41 0.30 a. 11 8.41 0.06 8.33 Au^at 7.66 0.10 7.59 7.99 0.19 7.47 s«ptaabar 6.33 0.22 6.U 6.33 0.04 8.29 Totala 60.00 25.14 34.86 l2.« 47.22 15. « 49.07 1918-1919 1919-1920 1920- uai Oatobar 4.65 0.82 4.03 0.75 4.10 6.74 4.11 ■oraabav 3.62 l.as 1.T9 1.26 2.39 0.29 3.33 uaeoBbaT 2.2t 2.99 -0.42 0.87 1.37 0.69 1.55 XamaiT 2.09 0.33 1.79 0.70 1.39 2.62 -0.53 /abruary 2.91 2.88 0.03 4.47 -1.59 0.84 2.07 March 4.29 2.27 2.02 4.90 -0.91 1.87 3.02 Afni 4.70 1.20 3.50 0.79 3.91 0.16 4.52 IfcT 3.66 O.U 5.74 0.48 5.40 3.a< 2.19 Jtrna 7.02 7.08 7.02 7.02 July 6.41 u 8.41 6.41 8.41 iilglMt 7.66 0.10 7.5« 7.99 0.07 7.59 S«i!t«bar 0.30 A.M 0.99 5.37 Totala 90.00 12.53 i7.47 14.pp 45.71 Mp5? 4SJ6_ 1921-1922 __192S-I924 Oatobar 4.65 1.38 3.47 o.zo^ 4.55 0.43 1.4t .■ioTailnr 3.92 0.54 3.ce 1.36 8.24 0.43 3.19 -w^ar 2.M U.98 -9.44 2.90 -0.59 1.79 0.45 Jaaiasy 2.09 4.94 -2.55 1.75 0.34 0.75 1.34 ?abr;ary 2.91 3.09 -0.18 1.87 1.04 2.91 Haroh 4.29 2.42 1.87 1.3« 2.93 4.50 -0.21 ^m 4.70 0.55 4.15 1.66 3.04 1.60 3.10 aaj 5.88 0.53 5.55 5.66 5.66 jma 7.01 7.08 7.02 7.02 July 8.41 0.04 8.37 0.04 8.57 8.U Au^iat 7.99 0.01 7.»5 0.05 7.61 0.03 7.63 S«,tmi>«I 9.33 0.05 9.26 0.09 9.24 6.33 Totala 60.00 24. 9S 35.07 U.IO 46.90 9.53 5«.4? 1924-1925 1983-19*6 1929-1927 Oatobar 4.35 0.22 4.93 5.02 -0.17 0.31 4.54 SoTaabar 3.62 C.68 «.94 1.36 2.84 0.56 3.09 Daeoabar 2.24 2.40 -0.19 1.75 0.49 4.41 -2.17 JamaiT 2.09 0.24 1,85 0.75 1.34 0.45 l.»4 Fabruary 2.91 0.57 2.34 2.90 0.01 12.78 -5. 9? Uamh 4.29 2.2? 2.01 0.57 3.72 2.74 1.55 Ajall 4.70 2.29 2.41 9.96 -2.23 1.42 3.26 "■J 5.66 0.01 5.67 0.18 5.76 0.59 5.29 Jim* 7.02 0.75 6.27 7.02 0.14 6.36 Jalj 8.41 0.01 9.40 0.12 8.29 6.41 iagimX 7.69 7.66 J.U 7.55 7.66 Saptsbar 9.53 6. 33 6.33 6.53 Total* 60.00 i.ii 50,55 l9.« 4O.su a.iB 36.60 191 7-1926 1986-1929 1929-1930 Octob«r 4.83 3.06 I.ii 0.95 3.90 4.65 SoTaabar 3.62 0.S4 3,36 0.69 2.79 3.82 DaoBbw 2.24 3.U -u.e? 8.75 -0.51 8.24 JaauaiT 2.09 0.41 1.98 1.92 0.17 4.95 -8.59 Tabiuary 2.91 1.82 1,09 1.64 1.07 0.80 8.U Uarcb 4.29 0.66 3,41 1.89 2.40 3.33 0.46 April 4.70 0.04 4,99 1.21 3.49 0.92 4.06 "V 5.86 0.59 5,89 5.66 3.99 8.19 Jana 7.02 0.04 6,98 0.02 7.00 7.02 July 8.41 8,41 8.41 0.04 8.37 Aagut 7.96 7,96 7.66 7.86 Seiitnbar 9.53 6,33 0.53 5.78 6.33 Totala 90.00 10.21 49,79 11.99 46.01 13.63 48.37 1930-1931 1931-1S32 1932-1933 Oatobar 4.85 0.47 4,38 0.33 4.52 1.30 3.55 Koraobar 3.92 8.22 1.40 2.54 1.06 :.62 SaaiBbaT 2.24 2.24 5.43 -3.19 4.41 -2.17 JaniaiT 2.09 2.76 -0,67 1.31 0.79 5.81 -■abpuary 8.91 4.57 -1.66 7.98 -4.77 C.04 2.87 .^areh 4.29 0.02 4,87 0.44 3.85 0.12 4.17 .,jrll 4.70 1.78 2,92 0.59 4.11 1.36 2.32 'JV 3.86 0.62 5.28 0.01 5.87 0.95 Juoa 7.02 7.08 0.19 8.69 0.07 6.95 Jttly 8.41 0.02 9.39 6.41 8.U Aa£uat 7.66 C.37 7.39 7.59 7.66 SaptsBbai 6.33 6.33 6.33 Totala 90.00 17.17 18.49 U,S1 13.96 ..«.«! i lASU A-e, (ContlDual) LOSS III C\'UUULTlu:. >HOM RESEinri.IRS OK SAN OIBK) Bim) CUTObCA RESntVJIB I la»4-1895 1695- 1396 1894 -1897 ;roaa daptb ftUafaU »at dapth Balnfall Bet daptb Bala fall Nat daptb Month of ,1 00 of on of on of iTaporatiai raaarroir aTaporetlon raaarrolr emporotlon raterrolr aTapoivtloE- In lae^aa in lac^oa ia lne::aa in Inaliaa Iji inobea In Incbea inlnebaa Oetob«r 5.M C 6.53 C.62 5.71 J. 94 KOTMfcM- 4.<1 4.41 t.ii -1.12 2.76 1.65 DM«sb«r 2.98 10.24 -7.36 1.33 1.5f 8.99 -O.U J&o^ry 2.77 84.87 -21. 5C 4.62 -1.65 5.05 -2.86 fabruarr 3.63 3.68 -C.05 0.16 3.47 7.32 -3.89 ■ihrch 4.39 4.79 -C.80 5.68 -1.03 7.65 -3.06 J«ril 4.87 0.88 3.79 1.42 3.25 0.17 4.50 li>T t.ge 0.93 5.75 0.74 5.94 0.30 6.36 a. 58 8.58 8.58 8.56 Julj «.90 9.80 1.03 6.77 9.60 Au«u»t 9.37 S.37 0.70 9. 87 9.37 3apt«at>flT 3.09 i.02 £.C" P.IV. 7.24 0.31 TotU* 78.00 U.91 2". 19 22.32 49.13 34.44 189 -1896 1898- 1B99 1B99-1900 Octobor i.si 3.78 2.75 6.5J !.*1 lOTKbU 4.41 0.86 3.55 0.70 3.71 3.63 DMSsbST 1.38 2.34 0.54 1.71 1.17 1.99 0.69 1.77 4.95 -2.18 5.70 -8.93 8.90 -0.13 ?»bruflnr 3. S3 1.56 2.06 1.84 1.79 o.a 3.48 Uarcb 4.59 3.71 0.66 5.79 -1,80 2.01 8.56 4.57 0.99 3.68 0.78 3.69 5.35 -0.68 Itoy 6.98 4.77 1.91 0.38 30 3.82 3.46 3.58 0. 8.58 8.37 6.21 C.08 8.50 Julj- 9.90 9.60 0.03 9.77 0.88 9.58 August 9.3? 1.C6 8.31 9.37 9.37 Septal &«r 3.09 L 6.09 fi.09 0.74 Totals 78.00 M.04 47. 9S 19.30 52.70 23.96 48.04 1900-1901 1901- 1902 1902-1903 Octobar 6.53 0.59 5.94 1.65 4.98 0.41 5,78 SoToobar 4.41 t.S7 -5.16 1.18 3.23 4.07 8.88 Q.03 2.65 0.42 8.46 2.93 -0.05 Jer_a.-7 2.77 6.54 -3.77 6.54 -3.77 3.17 -0.40 ?ebruar7 3.63 10.61 -6.96 6.00 -2.37 ilarcb 4.59 1.86 2.73 11.06 -6.47 4.91 Af.-ll 4.67 0.99 3.66 1.67 3.00 6.57 -1.90 Uay 6.ee 3.10 3.56 O.U 6.57 0.55 8.58 e.ee 0.14 6.44 July 9.80 9.80 1.23 3.57 9.80 Aueuat 9.37 0.06 9.31 9.;7 ^Dtsibar t.09 V.06 6.03 S.09 ^tala 78.00 33.41 :^-.59 29.90 42.10 29.89 1803-1904 1904 1905 190 )-1906 Oetobax 6.53 0.42 e.u C.94 5.59 C.15 e.u SOT^ber 4.41 0.03 i.36 4.41 8.U - 3.71 Oeeesbap s.ee 0.13 2.75 2.36 0.52 2.22 0.66 Je:tifir>* 8.77 0.68 2.15 7.90 -5.13 4.35 -1.58 Febrtiai^' 3.63 3.14 0.49 12.73 -9.10 5.98 -8.29 :iirci. 4.59 10.80 -5.61 12.60 -7.91 17.93 -13.34 Apr;: 4.67 8.U 2.56 8.83 1.84 8.83 1.84 ■aj 6.68 C.98 5.76 5.69 C.99 2.69 3.99 .'ana 8.58 8.56 8.58 0.12 6.46 JUlj 9.80 0.16 9.64 9.80 c.oe 9.78 Al^gUSt 9.37 1.00 S.37 3.37 2.40 6.97 jer t=r.: -ir 5.09 :.12 7.97 0.=1 -.2£ G.72 7.37 Tclala 72.00 53.15 45.76 26.24 i7.5fl 44. 5B 1906-1907 1907- 1908 19a -1909 Octobar 6.53 6.M 5.S9 2.78 i.e\ 1.B4 4.88 ::;Tar.bep 4.41 2.94 1.47 1.05 3.36 c.99 3.42 :'*eerbsr 2.88 7.30 -4.42 1.44 1.44 0.56 2.32 'i^,try 2.77 7.58 -4.31 5.33 -8. 55 18.13 -9.36 -^iru-ry 3.63 2.58 1.05 7.44 -3.81 10.00 -6.37 «.-cb 4.59 9.11 -4.52 2.60 1.99 7.06 -2.49 ..i.-ll 4.67 1.37 3.3U 2.22 8.45 0.17 4.50 £y 6.66 0.51 6.17 1.48 5.20 6.68 .'*-T« 6.58 0.70 7.88 6.56 8.56 -'-17 9.S0 9.60 9.80 0.13 9.67 3.37 9.37 2.29 7.06 1.04 8.3' je,-.ai.tsr e.08 C £.09 1.46 6.63 0.24 7.65 T;tiil3 78. K) 32. W 39.27 EB.03 43.97 S4.1B 37.62 190S -1910 1910- 19U 1911 -1912 ^:-. :':9r ;.53 C.05 6.48 1.49 5.04 0.54 5.99 r^ g--' "^r 4.41 4.66 -0.45 2.10 8.31 0.23 4.18 :- er 2.ee 9.41 -6.53 0.90 1.96 1.38 1.00 ."- -^- 7 2.77 5.06 -2.29 9.15 -5.36 1.04 1.73 ^;;-ua.-y 3.63 1.06 2.55 6.61 -2.98 3.63 j-cb 4.S« 4.15 C.44 3.51 1.06 15.89 -11.30 .:.-ll 4.6- 0.74 3.93 1.43 3.84 3.50 1.17 ■&y 6.66 6.66 6.68 1.35 5.33 .'ina e.58 8.56 8.56 0.33 8.8S .-uly r-.ao 1.20 8.60 0.51 9.29 0.67 9.13 i^U.-JSt 5.37 0.07 9.30 9.37 0.51 3.86 - :-.'j=D«r O.C9 0.26 7.83 0.23 7.36 0.01 .o'.t_s 72.00 26.88 1 45.12 24.93 47.07 25.95 46.05 Oatobar NoTaefcar TaeflBbar Jasuaiy Fabniary Jarab Aprtl Hay June July Auguat Septaabar Tctala Croaa daptb of evaporation In Intf.ea Oetobar Uormbar Dae aa bar January Fabiuaiy Inarch April Slay June July Au£uat Sarptaabar Totala Oetobar HOTe::ibar Da««c:bar January ?ebzuary ;iarcb Afrll Itoy June July iU£uat SeptflPbar Totalj October llovesbor Saaoabar JaiLiary Jabiuary Uarcb April liy June July Au^st Saptecber Totala October Iiorei±ar Decac^ar January ?ebniary aarch Aarll June July *" J'*^ Septanbar Totala October Nor ember I>aoeEl)er Jamary 7abiuary Itorcb iprU May JUSB July Aa0iat Septanber Totala 6.53 4.41 t.aa 2.77 3.63 4.59 4.67 6.68 9.8S 8.1s 7.94 9,68 71.81 raaarrcl r in Incbaa 4.48 1.93 0.06 4.30 9.50 1.70 0.74 0.41 0.57 0.42 1.90 0.08 25.97 Sat daptb of aTapontloQ la lacbaa 8.11 2.46 8.88 -1.53 -5.87 8.89 S.93 6.8V 8.66 7.76 6.04 9.86 45.84 6.08 3.26 3.94 3.47 3.97 4.5« 3.75 4.58 9.66 6.74 10.30 7.18 69.43 1,30 0.94 S.65 9.1s 9,86 8,94 5.93 6,58 0.36 0.41 44.15 4.78 8.34 -2.71 -5.71 -5,89 1,62 -2,16 -2,06 9.66 8.74 9.94 6,75 3.15 3,88 8.40 2.75 2.01 2.94 2.88 4.ee 6.56 6.91 8.54 7.12 53,96 1918-1917 0,10 4. a 5.87 6.35 1.40 4.09 1.17 0.94 0,37 25,28 35.60 -C.95 3.72 -i.s; -3.12 -4.34 1.54 -i.a 3.71 6.56 5.97 8,54 6.75 85.36 8.84 2.45 8.38 8.07 2.60 2.96 4.55 5.76 9.38 8.29 7.97 7.99 nis-m? 62.66 0.88 4.34 2.76 C.S4 5.66 5.10 1.13 0.27 1.00 0.80 0.40 24.06 5.36 -1.39 -1.38 1.53 -3.26 -2.12 3.42 S.49 9.38 7.29 7.17 7-59 3^.58 Croaa daptb of araporatlon IJ lacbea 6.86 5.63 8.85 3.83 5.46 7,20 5,60 7,53 6.99 9,90 10.79 7.53 61.59 r»aorTolr in laebaa •let daptb of aTapoxvtloB taebea 0.87 3.89 8.66 7.80 5.55 1.68 3.04 0.03 0,41 r.03 1.06 C.16 26.76 6.30 3.99 4.88 0.96 4.65 6.86 6.57 7.Z1 e.2S 10.05 6.68 6.11 75.63 2.35 5.66 30. CO 2.80 3.61 0,59 0.51 1.70 1.67 1.06 4: .97 6.5i 4,41 2.88 2.57 3.61 3.00 5.24 5.85 6.20 9.02 7.11 6.65 63.07 0.02 0.99 3.37 4.49 12.56 0.39 0.47 0.09 0.35 ^.03 22.73 8.75 7.34 2.68 2,77 3.63 4.59 4.67 6.98 8.58 9.80 9.37 6.09 77.15 -OT" 1.59 3.25 2.62 6.07 3.28 3.09 0.84 0.04 0.09 0.96 C-14 29.65 6.53 4.41 8.38 8.77 3.63 4.59 4.67 9.68 8.58 9.40 10.11 9.74 73.99 9.41 4.23 1.83 3.19 2.65 5.86 4,69 7,70 9,94 U.50 12,40 6-46 7^-96 3.15 C.76 2,48 3.49 8.01 2.83 0.68 5.73 1.45 0.O9 2.26 SS.o? 1.08 4.60 6.68 4.80 4.78 2.59 4.16 0.38 ■■■«' ■ - 70 3,38 3.65 ».40 -0.69 1.68 1,76 3.79 0.95 s.sa 7.95 10.05 7.1fl ii.K 5.35 -t.27 -4,85 -1.61 -2,13 2.67 0.51 7.70 9.64 11.12 12.40 ■^ /if- 46.17 7.87 3.84 2.86 2.77 3.63 4.59 4.67 5.17 7.38 10.51 10.14 1.46 L.77 20.7b 9.63 7.19 3.78 2.00 1.09 0.49 1.22 0.20 7.04 4.16 3.77 4.87 5.56 4.59 4.13 3.74 10.04 I2.«e 11.02 ^6 -PA 45.77 1.42 l.X 4.23 1.46 ^.04 U.07 3.31 I Ilk3LI A-:, (Continual) LOSS Of ZTAKUUTIOH mi KISlixVjiHS Hi SIK OUOO RITB 19M-1925 1985-1916 Oroas Aaptb Rainfall Hot di^tk OroM l«ptk talnfall Vat dapth Hon til of on of of oa of mpoi«tlafi roaarrcir on pontics •Tmpoz«tlMAb«r 2.88 8.17 -3. 89 t.ae 1.99 0.89 JaniAJT 2.77 0.97 i.ao 4.70 S.47 1.33 fsbrusiT 3.83 1.78 l.SS S.Si 5.09 o.t» llATCh 4.59 5.17 -0.5B 4.S9 1.81 2. 78 Apm 4.87 9.07 -4.40 4.87 10.89 -6.02 <*T 6.88 0.43 8. IS 8.01 0.47 3.94 JUD* 3.58 2.41 8.17 8.80 8.80 Juir i.tO 9.20 10.48 10.48 ioguat 8.00 8.00 9.80 0.14 9.48 3.st.b«t s.oe 9.08 ft. 74 e.74 »>«»il_ 11.88 26.88 ii^ai 77.0S ».S9 47. U 19<«-I9n 19«7-19» Ostobu 8.01 0.05 5.97 8.33 3.18 9.17 HoT^b«r 4.e: 3.18 1.47 3.41 0.12 8.89 0—mibT l.SS 13.21 -U,58 2.14 4.91 -1.77 JanuazT 2.31 1.45 0.88 3.81 l.U 1.41 ?*bivax7 2.01 22 .88 -80.85 4.98 4.0« O.M Ihrch 4.91 6.58 -1.8T 3.87 1.84 i.a Iprtl 4.02 1.66 8^.8 8.18 O.K 8.00 MW 7.35 1.90 5.93 7.S9 l.U 8.96 JUK 3.28 a. IB 10.44 10.44 July 10. SO 10. ao 11 .SS 11.33 Au«u«t 9,22 9.21 n.oo u.oo Septan t>«T 8.38 0.48 7.90 9.58 9.58 Totalj 6«.4« 51.55 17.91 _ 80.57 16.87 63.90 19«B-19t9 1929-1930 iNotoW 9.U 0.79 5.12 8.90 i.^ir NoredMr 4.12 2. IS 1.94 5. It 5.34 3«oflDb«r 3.54 5.65 -2.31 4.48 4.48 January 2.53 8.07 -3.74 1.83 13.45 -U.88 Psbruarj' 4.31 5.08 -0.75 5.18 2.42 2.70 Uareh 5.29 5.74 -0.48 S.3S 5.IB -1.80 ^m 4.65 2.83 £.00 6.48 0.9« 5.53 *7 9.78 9.78 8.05 7.04 -0.99 Juiw 9.5« 9.5« 9.04 9.04 July U.08 0.43 10.81 9,78 9.78 August 8.59 1.03 7.58 9.29 H.af 1.21 3.07 SeBt«ibflr 9 ^7 4.72 3.91 TotAla 78.4S 44.04 46.09 ■ 1930-191 I 1931-1932 Octofcar S.M 0.71 3.83 5.73 1.38 4.41 ;tOT«ab«r s.sa 4.51 1.17 4.19 3.93 0.28 ^•eer^v 2.90 2.90 0.19 U.09 -10.90 January 3^5 2.71 l.U i.ao 3.74 -1.94 FabiMary z.n 5.19 -8.85 1.14 17.78 -18.84 •Jarcb 5.97 0.34 !.83 5.44 0.49 4.99 AprU S.<3 4.89 0,« 8.13 1.17 3.99 Jay e.«o 2.21 8.39 7.40 7.40 Tuna 8.40 0.08 8.94 8.88 i 8.66 July 10.78 0.54 10.14 U.04 U.04 iugujt 9.17 0.17 9.00 11.96 u.g6 393t«al>«r 7. S3 "..67 ^.Q« B.9e > 9.98 Totals 77.34 23.80 ■i-s.na 7,1.70 ui.ia 3S.22 1932-1933 October ■».64 i.a. 2.53 yoTanbor S.M 5.58 Docflcber 3.49 9.72 -6.23 Jan-asry 2.95 5.19 -6.34 rebTU8i7 3.46 ■w.C-5 3.39 Storch 6.1B .32 5.88 i]irll S.it 5.33 0.33 itoT 3.50 2.70 5.80 Jun» 8.82 0.13 8.89 July 11.06 0.S7 10.71 lu^iat 9.9< O.U 9.88 SeDtaaier 9.4< 9 9.44 Totals ■-82.18 aa.M 49 .» [1) 80 per cent of ralaftjl at C-.:ja=iaca. TA3LE A-3 MONTHLY DRAFTS ON FGSZRVOiRS 32,500 Acre-feet Total Seasonal Draft Guyamaca Reservoir El Gapitan Reservoir San Vicente Reservoir Mission Gorge No. 2 Reservoir 11,600 acre-feet 116,900 acre-feet 174,500 acre-feet 29,200 acre-feet Total Storage Capacity 332,200 acre-feet : Month ; Irrigation supply : I\^nicipal supply : Combined totals : In acre- : feet ; In per : cent of : annual total In acre- : feet : In per : cent of annual total In acre- : feet : In per : cent of: annual ; total ' : January : February : March : April : Liay : June : July : August ; September : October : November : December 70 : 50 ': 140 390 440 540 : 690 : 740 : 690 : 540 : 490 : 2^0 1.4 1.0 2.8 7.8 5.6 10.8 . 13.8 : 14.8 : 13.8 : 10.8 • ?.8 4.4 1,705 ; 1,540 1,925 . 2,118 ': 2,585 : 2,805 : 3,107 : 3,025 ': 2,640 ': 2,337 : 2,008 :' 1,7-5 6.2 5.6 7.0 7.7 9.4 . 10.2 ': 11.5 : 11.0 : 9.6 ': 8.5 ': 7.^ ". 6.2 1,775 ': 1,590 S 2,065 ' ': 2,508 ': 3,025 : 3,345 :* 3,797 *: 3,765 ': 3,330 ': 2,677 : 2,493 i 1,925 5.6 4.9 6.3 7.7 9.5 : 10.3 \ 11.7 : 11.6 : 10.2 8.8 : 7.7 ': 5.9 : Totals : 5,000 : 100.0 : 27,500 :' 100.0 ': 32,500 : 100.0 A-20 I I 'itk u 088 2 ni ^ m u ADC) .-) O «- D c c c o ^ coo 111 ; 1 1 ,. - . o ■- *• ■ 5 00 •» q m u Si Hi •» V V V en N A "s "S ' 3 f" -its « •* » &&& U U ti c r > > r* 000 3 3 Ul u h S O B t> ^ elf si g^ s S £ i :e£ 111 go •i -rt "* • q o — • sssi C£ S - » : » k P 4>N^C»ISiAM 000000000000 ooonoujc^ooooo o 00000000000 : 2 1 ssssass^ssas 'Sal 06a * (D<0<4io O 0) Al u) to ^ Oi « O ^ .H O W .-» .H N to eg ^ o o o to o> tOO>qi^OOOOO in N aj rt to 111 O ; 10 « Q 3 ^t-iooioototot^' r^\-l en" MM (0 1 oja)okO'-^Mo C^NNMCMC>r-(iOCO O*»^c-p-t«.e-c-e«-H(0 O«c-C0t<^Ots oicnm9iotooe^e^c-n o09o>(>naa)(Dc~oin r-c^tftooiotf^oiootf 000000000000 «o 000000000000 Ok 8 O 0002**^000000 D 000000000000 t> QOQOQOOQtOC^tOO CO ^»NC«lO<#9«V)OeA . lA-^a r5rt*OP-t-.rt r4 « 10 n ON«| to I iinr>90»f- 33113232311* A OO^OiOMNC^OOOO 0000000 00000 ooooooomoooo S o o c- t- ^ V ooo«M«% p ** o o *» ^ o a Ji h^t^cr-awr t*(Dwo0 « o < o.jD p 3ai o 000000000000 OOOiQOOOOOOOO 00000000000 O o oooon^oooooo 3 000000000000 o 000000000000 o 000000000000 S 8S88SS|eas8S o 000000000000 o 000000000000 i ^§3?2i3i3iig 8 Ksassasassss d to to to 10 f? « sssssssassss 5. assaaaSsssss h 9a]3]<99»9( 'ass-s o oooooooooooo oooooooooooo °^1 -i S3 ^. S " i ° 5 S _, o A a ffi 4« I* ■S5 35 » • ■* ■ '■ • « • -4 ■ O ^ p ^ = yll oooooooooooo b gv • •• -f 5 q -, SB'S - 3"s'» . -» •• a H 8 3 - •• .^ 8 i jQ •• (. •* q k A 3 -* y o • • u U • ■ ■ «4 t I " I E • sa a-ss % 3 • o I, ^ ■♦(n^»»r^Oiq;o«»^(0 OOWOCOOkO'HOjc-f) OOOC^C^QOQOOOO \ °°ss5er2 OOOOOOOOOOOO ooooooomoooo » iH O O (0 M ??3l8°°°' ooooooomoooo ° ° 3 3 ;? S S s ° ° ° ° **Ss •*•?.•• ^ORn<-i*^a-4a->»3^m OOiHlOtQlO^MOOOO '38238 i8S3S 0} A lO M 00000 ^^3SC'~*oooooo r^lh'^ ■ d) ». • K I* r •jfll A A El q *» O r«So ojp 3 0? R.«3^ aS ^09BO>«B«d-^=l>^>r>-4m . Hal* * s * * .%" .s • MM** -H d a d • • O «• e •• 3 O ll o o d~? i K o -* ?J 2i Pi • I S op « « I. r 1 ^ ■ i. c o "^ • •> a A 5 « *> • ^ 5 *. c i box* r| s o o • •> fe q 4 •* c u MM d o I^ " •• *» -*^ • ssas Sjla'T & a 'Sol o E d e O (• C -4 ^ « o -^ o — . o ** 5- E "^ .at. er^ n o u a; d d w « o o o « s 3 ■■ S a> »k C ^ o .o A I. ^ ^ a OOOOOOOO oooo oo oooooo oooo OOOOOOOO oooo o oo oooooo oooo OOOOOOOO oooo oo oooooo oooo OOOOOOOO oooo oo oooooo oooo OOOOOOOO oooo o OOOOOOOO oooo OOOOOOOO oooo s3^a323i82sl OQOOOOOOoOOO OOOOOOOOOOOO OOOOOOOOOOOO O OOOOOOOOOOOO ! a ' 3 a 3 s s s s a i OOOOONO^NOOO >8S|3f •H « 4 to OOOOO OOOOOOO ooooooonoooo O OOOOOOOOOOOO I V x*ja If 3 O OOOOOOOOOOOO O f^OOOOOOOOOO J o OOOOOOOOOOOO ,« oooonaoooooo O OOOOOOOOOOOO O OOOOOOOOOOOO OOOOOOOOOOOO j OOOOOOOOOOOO O OOOOOOOOOOOO Jl OOOOQAOOOOOO O OOOOOOOOOOOO O OOOOOOOOOOOO 8 |iSSri3|ia: ' m a ^ ^ ^ nnn* § 38s?S3g§|g§3 o ooooraooooooo 3 OOOOOOOOOOOO »>Ainioioe-Eoooooo CD 9 t- ^ W 10 3e;5T r>fMOO OOOOO s °^ag||S|g8§a 000099400 oooo Qcoot'inooooooo OOOOOOOOOOOO OOOOOOOOOOOO 0009MF)e«)0000 ooaooooooooo ^ lO -i * ^ p ** rj ooooonY<3oooo oooAnvipnoooo •^ O^i-IQOOOOOOOO 4hmhum ooooo;f2^ oooo J °3S||SS|g8§« 3 OOOOOOOOOOOO >OOOOIQ020S o °Sdge833' issi 4*OeSV3Cll*4 VKp** ^.a.oojpaoaq.¥3^?6* *o c^ioVwowHt^MaT o9a}cDO(0(D«-r-3 SOOOOOAOOOOOO 3:^ oooaoooooooo °°°«3iSi8«"° OOOOO-liqOOOOO OOOAOOOOOOOO ^ U U y, « o OOOOOOOO ooota a °°°°3aS OOOOO o OOOOOOOO oooo OOOOOOOO oooo 3 °°°°3Ss oooortQO o oooo O OOOOOOOOOOOO ■^ a«2a ass 5 i^^iHUun f °°=°age OOOOO O OOOOOOOOOOOO o I °=°?g||a|8-° OOOOOOOOOOOO OOOOOO on«ooo oooir>M^M«oooo ?8d sa OOfHMHMinHOOOO "sa Oi-«H «t c f- K' CD ^ ^ ^ :^ A Oooooooooooo «1 8*. • • >k w a m a ^ h m *• L O OOOOOOOOOOOO O OOOOOOOOOOOO J o O O O o |8|ajs°° ,5 oooogs^gjjs •o o a •i O OOOOOr^igifOOOO O OOOOO fSSsI'" oooooogeoooo i oooooo^ot-ttoa ■ » . . . . o o o o o n o> O OOOOOOOOOOOO €1 t O N r- n 8 as a a 3s"'v?3Sa§a3 00 0000000000 £ OOOOOOOOOOOO i 3»»°?S3S5S2S p>o<»iciA009ia«Oa o 0000 4 f- * 0000HQQK}&00 8S§isr (O o rt o n ■afl ,>»st •8 6 t 2 00 OOOOOOOOOO J 3 " " la OOOOO g °°°S«a8S8' JSiir 00 OOOOOOOOOO 00 OOOOOOOOOO J 3 °°8|3||2a°°° is ""Sji* OOOOO O OOOOOOOOOOOO O OOOOOOOOOOOO n n -i 9i tk '-t n^Aeon 00 OOOOOOOOOO 00 OOOOO OOOOO s HSsSSilsiSi - - - - - - ------ ^"CctOfD' ' ' « « « 2 883° n t"- rH 00'^9»0^c>t-000 3 - c Ti f A ti 8 •I 000* 8 : i * b P V OOOOOOOOOOOO to i fi-S OOOOOHQ#00«IO iir OOOOOOOOOOOO op • • C V M • C • OOOOO 0000000 O OOOOOOOOOOOO Mooffie>c-c>n'4Mtf)Q 9(>(»<>oo>-4<>n n rt r5 5S rt fO rt OOOOiQr-oo»«o« I -4 M rS n F) •-* 00000 a > o • SIS ia. u a c 4 •> «-• 4 o k, « t -< u U ' *i ^ .rt • 00 « fssi t S5 I OB U C £ J , 3 38 air 2ttooa)AMe4Q«r-io lA .ff) 9 H •-< OOOOOOOOOOOO 000 OOOnOOMO O OOOOOOOOOOOO MOOOOOOr««DH pa-3 OOOOF^eic^ttOOOO oonMonot'^oooo '38; OOO-4(0eM»O 00 O i^S OMO^AAOOOOMO •83 Tt *• • • >»h o OajsALi t» a 3 ""-3i||3SS^a r^ o % A A U 4 t r ^ 3s«°?3a32li! I aSisSa'SisiJi a53slgs8s3gs r4(soa}(00>ap N^AS)0nc«<>nM it a'! O OOOOOOOOOOOO ^ aooooooMoo**- *■ ;? • "-I 31 9 O»a)NMO0«OOOO I I ^ e- 00500 a U 1^ »• r_ O ». « • X li o ooooopoooooo o oooooooooooo iTi, ^ a o o o t- id •^ ft- s 118123°- jl -§8«|2- •as 1 5 m^a Xi ^ h 4 ^ -L o oooooooooooo lO ooooooo oooo o OOO *«o MOOOOO j« OOOOO jj J -«oo o ooooon «ooooo ooO'-trtoooo ooo oooooo inooooo '13 oooo«)oooo ooo ; V A ,8^.g30oo ig ocgpgj O O O O O . 41 ^ C 1 £? = -■'■ :2i OOOOOO OOOOOO OOOOOOOOOOOO O ^ « V. -^ O t. C I _ > 9 -' * h d ^6? « Q a> o o m u O *4 ** c p nt c -r u d P. ? ' o ti C -3 I (J ■ -J I, •> o u en ti d 3 « c Si? laS|§S|5||3§§ O(0«>^o^-^-F^-^•e °°°8sseda°°° O OOOOOOOOOOOO O OOOOOOOOOOOO Saa jssssssas s «>°gasg9°°°°' oooooooooooo iS3^§s3§|g33 *^-'*^»'oa)»orti-io 3Sail83S§l38 ooo ooooooooo U}OOOooOtOO«ir)M K i-( d ^ ^ oo»aoa}«>0kOooo I I I ooo««9atinoooo tO o ^ m e- ^ o in P (D --i Til »o in iQO<0rir0«c4OO(0MM v> k p^ o o»>o»a t-i o c- oootDr^ sn"s88asssss5 oooooooooooo rooooooNo Ui '88SS8§g< w »" ""• o •• s • ^ U c 0*»> OflAbt. ^CrHWp OOOOOOOOOOOO ooooooo oooo o OOOOOOOOOOOO ooooooo oooo o 000<#e4ChM00000 o oooooooooooo o oooooooooooo i IS3§?§a§3SS§ OOOOOrJ^MMOO O ■a? OOOOOOOOOOOO oooooooooooo e>no»ov)o3ia>ninS •3 ooogvoffioooo o oooooooooooo n a)-«»«o9AOrtr-^A g M •• rH H r-T r^ oT fl n vT n vT jiSR833358aa" i SH||§||Elia o oooooooooooo S goooooopoooo 009'4-19M<-«0000 « « H B^ ^ vs s ?? o g 1 8 e ° ° a ° ° 40RO>^»<.di.4:i<^»«4» O0o00ai(Dr^«000 5^ o oooooooooooo § 2S8S53Si5S3^S a'a'sssassssss E *°38S|SSS°§3 *> ^ o A o oooooooooooo OOOOOOOOOr-IC-M 3 as OOOM<»MO«}0000 a's I ooooo«^^oooo 'ir OOOc-oonoOrHC-n 8 " esg as-" s , ■• •• e E o oooooooooooo [o ooogiQooooooo 8 °°°883 o oooooooooooo oooooooooooo oooooooooooo a °°°83S o oooooooooooo o oooooooo^no 4 n o f o » O e' 3Q-^90r-('4»O '^OoaiMo^-eST^Sr- n o o o m 4 « OOOOOO o oooooooooooo o S sSSsliSyS^sa g ^F^V^ioSa 8 1 ? sssSslgssasa S o s o oooooooooooo 5°°°°°°s!ssse owmojPiQ'H^o ooo ??^a3 > on -< ^ r> O 4 f - ., ^ 6 t h t O ^ •* I - - - - - ^OKa>->*ba-4a>^*9^m h\ ^ k V • Is »• ^ SS:?l|l.^*IIU5 oooooooooooo i - - • I o o o r> e S: 1 o o o o o fe-S Z " ^ 0000«^A0O00O0 OOOOOHOOOOOO c o — ** « G • SS't - I. a 6 u " *» •I -*~ « C O* • D • a V o • -• t. i 3 fi-s I ^ oi ^ oi o • 4 •« 4 m o o o » a rH ^ - - -> o «> ^ ^ OOO'OOO^^ NC-P«0 3asS8338 1-4 rH <-( ^ -4 ^ > ° ° ° 8 5 a s ;! s a ° ° a) n^9«o«}a} 1 ^o«{»ooo^«e-a)0 s 3 s s" 3" J J J J 3" 3" g 3 3 s s" 3 3 3 3" S 2 3 3 •H OOt-I^HO^OkOOOO 8 3 1 S 3 ? O O O o o c Q O O O O O oooooooooooo 3 oooooooooooo OOO^OJi^SS^C;; rH (5 rt rt «o S — , jW0000C«'C-t^^C-0 n n [O to lO ) A « •> o oooor>0r4ooooo p) ? » o o c4A^^ionno)(OiOco s ssfeasssssis ooopot-gooooo § °°°ii5S « OOQ^OOffifiCoOOO O-«MOOO«>Ofr-<0C~O g '-^ -T « «n 00 y •9«O^c^9<-4ne>-04a A ^9 n c- O <) n O ^ (0 laoiOffiMMOO e3J ^ P^ ♦ B 9 S el o rH c« n A «> es J, e k. E w O • -- C I e » f-i 0* Q ■« - O) m c^ M o oooooooooooo g4^M«acqUAa>(D(D ^ d :3 d d d d d d ddddddddddd } o c« n ^ <« (O O OOOQOrtOOOOOO -■ n ^ '« n rt rt SSoSMOCSOCDdO 33333da33ddd I aaS3lS§22«3a s OOOOOOOOOOOO oooooooooooo Su-- .5 fe^ i :- ■ h D* ^ r^ « O •-. b. u oi d o o o o o o o g J n g ijj 3 yg OOOOOOO^Sl'^S' 8 9"^ M « f>) ta p QOOOOOOOjfS^O 0000 ooo» sis^s 8 3 ooooooj(>io «g°28 « « X 8 J5£ O^^OMpjpMOOOO I t- S C- oOMtOrtW««00000 C £ ^ M a 0} s 9 r4 C- O O « ^ o n « 00«0H««*3P0«0 ^ -0 r4 » '-> -^-Bo 1 ^oa!0>-»fc.a^a'->'^^» ° 8 S S 9! ^ 8 3 3 8 S S c- a ^ « ^ k « b^ W oor-ior- k « • St L c 'if-i • j9 « U 4 •* Q ^o»a>->AB>«-4» 'mm' a •* « Q B * : •• 9 U O JP I isiiili- i se88g88*5°g8 *' "" k k " X " * " " • 3iSb»lE«d ...si ^^o»0'^«»s-4a*7'^^ h B W •» •— Vi 'an J. 6-6 00 • OOOOOOOOOOOO 33"* 000000 000000 QQiQtomo aiAinc^iao loatoc-ina) ^O(0t^r-i4 00 000 (D4>-tOOOO S^' 00 0000000000 ooooo ooooooo i Issgeggg^ggl oooooinp}(»^ooo -do •'•as o oooooooooooo |o K oooooooooooo OOlOgOOOOOOO «4 •-« -4 «4 •-« -4 ■>• OOOOOOOOOOOO jo iiiiiiiii oooooooooooo o o oooooooooooo o oooooooooooo I sS3°'SS3§f lis oooooooooooo oooooooooooo (^ oooooooooooo o 3" 5 8§ir°°5i||| liasssssaaaa"'" J i °°='°?S2°°°°° 3 o oooooooooooo o oooooooooooo 2 I ■ oooooooooooo rt oooonH*rt(»»>rt»> co « o c u si:'; CO V :e5I 3 000000 000000 «OOoo o oett^HXO ^ Esaefsassssa 3 assss^aRBSRS 2 fti«^^^ojo»(0««rtrt 5 %tr%Hinn ,n P?t-<>g3t-f-<«>or-r-*coc g S'SSaessssa OOOOOOOO 0000 o-fo-««i»n«eoo 00 "^33??g3 OO'^MO^^OOOOO P- H <* ^ 00 M ^4 » S >S jogoj||gog5|o a u • • >> L a ^ m £> £t U 4 *» " ^OKO>^i»2<<3->>^^M „ OOOOOOOgg gqc oo«>»)»}mO£-oooo o o o o o o g fl fl o 00 o 8 t:8ag8S8«3|S3 0000 MiHMO 0000 si" 3 3%aSSi8S3S3S M o oooooooooooo a gooooooogggg 9 9 2 °"^9S-aS2Si3 '383Sa2gss8 gs«||g|ir ■ A r-i 41 n n n O OOOOOOOOOOOO 3.! ' 3 o I si 5 00000 OOQAffit*'- sisa 3 5 2 °°S!888a|°°°° 51-°^ 23? Illilllltitll illiilllbjill i^iiiilllliitli iiissl^ll^ d u K ooooooooo ooo J; — I. ': ?. „ i " U " 2r op * e t r 1 t - o — • i m u — It s u « »< « O k " «> ♦» -^ ^ B fl o ■' • SS9£ o oooooooo ooo oooooooooooo oooooooooooo Saj 9 ^ ^ ^ vt ^ aJr^^>l^^«c*0(9rtP-0 (---tsit-ONWOrtoinc- CO[OMMM«WWr-tO(»

in>-ip9000oo I oooooooooooo o oooooooooooo !o oooooooooooo o 00 00000<£>!Q00 o O OOOOOOOOOOJ3 |o OO 0000 O 4) -• 4 c a k : 55 t> a c O O 41 P ^ = A CO V O M »• oooooooooooo 282SgS8aSSSS iisggsssgpg aSoSo'^^'^_<0*noB o oooooooooooo ft) a)^»p-iooinortp-c-ri 0^lO«SiH©I«0 o ooooooooooo o oooooooooooo HO ooooooejioco* Mm ° :; V 3 s « s! S ° ® ° ** I 'Slisil Ma)Ooc^««orton» I k tt o >i U I » q JS ^ 5 I o a s 5 t- u TJK If} o fi S 5 t' V -^ n >i p *• aoooo -o oooooooooooo (D P * jo g 00^*00000000.5 ssgsgxssssa" 8 °°°°§S5£i82i 8 S3?3S|32§§5 asass'sa" ; aaaaiaa'^a*'"''" S^^'d^SSJXSSS"*'^ '• OOOOOOOOOOOO (D rt -H ^ N It" s" OOOOOOOOOOOO 8 0>0(>ClrHM(0 ^« Mt-oniOr^&nPiioo^ OOOOQOC-OOOOO oooooooooooo 8S35a8"*asSS a sssR8g§HiiS o oooooooooooo o oooooooooooo Q oooooooooooo o oooooooooooo o t^^^ie^rto^-wgjt^'fw M e>*a)*«oo«^^QO«H'^ OlOOC-'*«i?>lO'HOtl> 000 ^^G-^OJ-felOO to MMS00'4 -00000 <» » (D(DC~ O _ **(o^c-BOOOOOo I D OOOOOrjgOOOOO rH n lO M t-ffi^HQinminioE^iAO oi^vc- ono«'t&-C"« 8 SSSotnonHnood CD M O 00 W m 9 01 lO HCd K S 8 a 3 3 5 8 g 8 8 S i lls3i3is8-8« g QOOOOOO ^ 00 0000000000 1000000109010 Sin N § °ss8ss|g°°°° s °3»aa8gs°' OOFIOOMMOOOOO 0) M .H U7 to -4 m tfl n ^ N 00 ■^SQQ"^ "foooo 838a8gSgSS°S -^oaaO'-jfc.a^afT^^OT issisl'^ p3SSi(Ss|^J§g|6 ** o SB cS »» fc. 3 '4>Qe«9OOOO ;3as!ss3sss 'ssdissdas" o* u) e rH o '.4 SSSSS OOMKlOiHO^OOOO t:oi.»> oq^Mu>iC,-j&c P900S do ooinM^09OrH oooAonoooooo '8S| OO OO ooo^oo^o •ac i d « n n A n *- o — I ^ vi c. • c « u o o c • t 1 I!- 6 S|s?Tgg;i|ii I83S888S8SSS t|7i I §*8S||8|2°«3 OOOOOOOOOO OO OOOOOOOOOO OO ooo^oncjM^o OO OOOOOOOOOOOO OOOOOOOOOOOO §si^3S|2Sii^ 0999(>i3n»Q»a)r>' g ooog««-3-oo< S B^ffinooMr^o^i^oe ►•o«onqn»>!Or*(*^ O ■ -• Vi o • ^ e: ■"^ s- s ,s ^^i a d c •> 1 C »• -H ■ o o o > V- <] c i o u CO » ^ I OOOOOOOOOOOO 3 ^''"liilSil^l a o oooooooooooo gooooooftfigg* 0«q^«Vlr4'H0000 *- a ooooootii^dS g?si oooo^-ii-i^oaoo 3S ^agjssss^**"*" > K> O 4 -I r4 ^ C » d a rt • o *t A 1-4 a ^ .-* ^ N I C • " " 1 u *• X B ai.-MSAALd Air «c .3o«e3E.uw •>t9*« .-'^"^'^<'» s t ! : ^ S " ; « I Ef D^ • /> jO I] 4 o oooof-^ooooooo o oooooooooooo a °3.s||3.-o°° i°°53|Si§i§j5 o o O O O -i • o o ooo o O O O O p £• £ SSsSSiSS' oooooooooooo ' ^^^^^!n*'«ldB SI n n 4 n a 333' « X - - o oooooooooooo o oooooooooooo S38?s;ssSiss o oooooooooooo o oooooooooooo o oH -4 ^ iH C 3332; « e«- e- « n 1* rt o o « o «> «> « OOOOOOOOOOOO a oooooooooooo I S|3?«3iiii 3 39882IS38S35 8 ss-3ss35s§|gg o oooooooooooo ||S|S31i3Sll| dSS38al288S8 n ^ ri Q lO « H o oooooooooooo soooooomfr- s-sss 8 °°338gs3S°°°° oo*o*^c*ooooo o to fr- A c- o ei N n Ar>i^nl> O OOOOOOOOOOOO >H OOOOOOOr^C-NHO n m '« ^ o m n n A f^ ■-( i-i w >o A o 2 o r^ w t- c- P- »M^ IsSsSi «s £»a«a4£ls^llll3 ?s o oooooooooooo § s°a?p2«' « o o o *2 gJ d o o o o o o 3 OOOOP-P-OOOOOOO as s s°88qag«' o o o o o o o o o o o e^o o oooooooooooo oooooooooooo >o«onM^»oooo ■^ w S '^ o oooooooooooo Soatwooqor^ia^^o iB»9^A9Pn-«<>oA i ^laSSsagi^li I i 5 g i 53 a IS 8 11 M 'DOco»q} g 5*S§g|S|SS23 O OOOOOOOOOOOO S °9f:58gaS°°' o o o a o o ""3338 1 ^ o X a >> •« a -^ a ^ >i ■< m <^ gs I APPENDIX B t' MONTHLY PRECIPITATION AT MISCELLANEOUS STATIONS f- IN SAN DIEGO COUNTY In the discussion of precipitation presented in Chapter II it was pointed out that only about twenty per cent of the available records of precipi- tation in San Diego County had been compiled and published by the United States Weather Bureau. For this reason it is believed that a compilation of the avail- able unpublished records of precipitation will be of value at the present time, and it is presented in this appendix. Since the publications of the United States Weather Bureau are in general circulation and easily obtainable in most ••ities the records of precipitation which have been published by the Weather Bureau are not included herein. T'^ey may be found in the "Climatic Summary of the United States - Section 18, Southern California and Owens Villey" uub- lished by the United States Department of A&riculture Weather Bureau, from the establishment of stations to 1930 and since that date in the "Annual Sumr.iaries of Climatological D..ta, California Section" published by the same agency. The data contained in the following tables were obtained from various civic agencies, private corporations and citizens of San Diego County and environs, Tne limi- tations of time and expense precluded as extensive a search for precipitation data as might have been desirable and it is possible that additional stations exist which are not included herein and that some of the records shown as inactive at the present time are still active. Many of these records prior to 1915 were published in WL"^ter-Supply Puper 446 "Geology and Ground Waters of the V/estern Fart of Stin Diego C^-unty", of the United States G'jological Survey but since this paper is now out of print they are republished at this time, 3-1 The various precijitrtion eeging stations, the index number on Plate I and the period of years for v.-aich records v/ere available at each sta- tion are listed in Table B-.l which is an alphabetical rearrangement of the data presented in Table II. The monthly and seasonal rainfalls at all stations for v.hich records have not been published by the United States Weather Bureau are given in Table B- 2 .. The name of the observer or the authority from whom the record was obtained, the index number on Plate I and the location to the nearest section of esch station are given at the head of each individual table of precipitation. B-2 ? t 5 •§ a • 5 .B s2^ '^3 , I I I I I I I I I t I I I I I I I I I I I I I I I I I I I I I I t • I t t I I I I I I I I I I t ' I I I i I I I I I I I gis^iiici^ii^iyr'-^^*§*i^ii^i^P-ip&-^p^^ti**iiiii*i'r-i^^iiitfiiiii I KN^MOj «N«-»«* ■-••" "^W fVr* te\tt\^ Cy ^ »* t>\.J ^ J» «• K\f-« «^ ^ »^Oi ^ Ol r-K\»«-\J» •* ^ t^^ »<1 W^K^J•* KN«I »* (r\«%M iH m |rM5«.38SR!«>5''"tfS«K^'-»8~*^l?jr«:^' : Ra*KR5;3 RS KtRIR« S- - - - -^C^^ § asa S*Rai-ft»6 g>?'-S5lf - 93*?^ RRSSg C5K8S5 Rff* 5r»*«5 « X. « o 8 I h 2 3 X s 3 t 'i h • I': |k 'km *' -*£ • ^ p. o ». -.1 l«« ■~D * • ^^ m tf ^- S.. 188.. « « a ^ d < [. h k ^ V. t, o o i4 p. a o SS& 13 s c4Ma oA k • «,ww « ^ K O «2 lllllllllllll«»lllllllllllltlllllllllllllt>*>l • t I I I I I I t I I I I I • I I I 1 I > ■ I I < I ■ ^ ^ rH ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ .^ ^ ^ »#, • • • -« « . a te5 = |e|pg32S|||pg|Sr|»||g|2f||8|||pHg|gS|S|8g|||PP|||g^|^§||||8|&pgSf§ -'.el •fi'!eaia-3**»38s^s!-*-*8rtS'^i-'^siM;Tt;3R28ass«-S8isaf«a-'^R-^s^Ki'>2ss-?s^«'-^s'^i?ss-'>^ss- j (Siif-r— ^-^-ff\»^^r^i-H«f\^CN ^&^3»s»^ss^S23*^SRaaac^'^ift^^i^2^2a&5cg?:5'^RS^R8~e^s?|«§iS£^3f=5g£B .5 ^1 MB t. •&. asflu*«4 k •••»*>«,:- ««»aa Sr^^r^ri log **9*' •***^R S^'fifl*''^* 53 gill Si |3 I S88S8^SS8S;^SBSS^o £ I I O033J3 0O03333 O 333l o o r4 3 #4 d di 8°3°°SSS°8838esg° o a • 4 2 S S S 8 S !! 8 S ^ S S S e S 8 8°°°8R5!33°gSS8°59 •-* ■* oon •-i I -111 oooooooooo^oooooo! sa d3 is el SaaaaooQpoooOQoOol '^o aasaaasssassssssst t| 1 SS8J8SS O JOOOJjO ° i i 1 1 9 ■• 9 9 -4 o d ^ ^ '«■ 88S88SS « M r^ d r^ ^ d J d M^ n d ^ - S3aa»8s g oNn«tdd'4 i 1 S^SSS28 i 1 SS8338^ m ddddddd s d HO do w i • oo^^oooo 5 d -H 1 8 n 9 1 gO-OOOO 3 ° ° - ! 1 o o o o o o o 1 '4 I 5 i I » tst sr • o aa 28 £5 Ji ■♦ *■ * f •( *" « ^ H w »» S n • < -i 9- n ,F^ c- r^ ^ r-t ^ ^ ^^ n 'do o o o rH d d i r4 ^ M d d S83S33!l°% S?888jf|^ O 3 O «> M M d -4 a « « O S e o o 6 o A c ° ° sf 3 S ° °i odd I! o o o o o o c ' OOOOOOoj ii e o S- a (3 o 8 «> 3 S « 8 o o o rj o n w > o o o o o 8! m o o ai ^ S « 3 a 8 n o o d d o ri a n M X « o o o d <-< d d 52sa°3a; M d ^4 M d d ■ e; S S S S S 3 31 t^ f4 ^4 o n n o j |SS3°°388 " « d « d « « 3SS°83°S • ^ rt O ^ M 83&°82^8 o n o o o ^4 d OMoao^oo d d d > M o o o • o o } o o o o o o, ^ 8 ■ A O S. Si i i8S3SSSd£3i;S:)S3'S38&i2SS3 8d3«S38(!S8: yrJaaSSS-'sa 838 3^5385 353333" i«a33a?,33aa M O O O :i ■ o d3 I" ■• H a o • -• • 2g « — 11 • — -* o a^ o • !«. SSS88S°S8S8S°°°8a°8S3J°83a°°SSS8°S3 O'HOi-ti-tO OMOOO r O O O i-l ^ o S888 883S33°Sd%;^oS9i3°3d3883 3 33^^°K,S3 oootooortooaH oooo^onn moohoo^m^oo Minn _g$g?SgS2S8SaSa8SS3J3g8853SSSSSgSE:S j'^rH-Hdd^d^dddiHrt«rtC».HOHi-toai*»e-M«J'-<«3«o««iwfJO ' g 8 8 ° 3 S 8 a S 8 S 8 S 3 S ° S 8 S S S 8 e 3 S a S ° S ? ^ 5 S 8 S o88,8S38SSSSS8 3tSPSS3SSSS3SSS833|SesS • nA<-iN^i-iO)nnr-^9o«)O«i«)««09j-tOiH^«nooooo>Ha>H >(omo^c>nooQn^i»oo Q O O O • ^ O d M )3I?SS8; «ON «>r-(OOMMO<-tO>0>^OOMa>OOi- o r- rH 1 o d o O O « O -HOW -Howr^^aooo^ oo o > o 9 o o o o HO « O 1-1 o « o o !gS°J83S°Sa''°8»'""'°°8°S Ido OOOO OH OH •! H oOoel^•o^^•OHca«^-ooae^no^^■p 9 otc^H «^oi3«Se^H K«r> ««c^ d OHO OO'HOOHOO HOO NOr >Qoaiocioc O IO H O • H O J O I d d 3(D'*o«o«r3rjwo^'a»a 999ao(>99<>c»ai ^8S l3 !gRSP888S«'tS8?;85SaSS£S3g8a8Sa88? 1^ |gd3gdagd«::1;3SaK:53*33^a; OOOOOOMHOOQ^OOO ooooooogooajooooo OOOO -^ o i is it 9 C • o O) I* 88 5o«g53oog|Saa8°63''3a8°°°°8°«'R8°a O OOOO ggog-3og3SSS8°3aS8°88eS8S8S8g33 « o ooo o o 100H NOOO OHHOiroOOHMMOO 8 8888 5; 383^ ''"►SaSSSSS'-SSS" 8338° ='° 888888888°" 8. S8SSS88e8°388SS8Saa nHO«««no^ 8S388S8S3'?S3^388 88SS38^88888SS3 > •# a o M ^ « 0«*92^A'~<0*0<^0000000 OOOMO OOOOOOOO 1 - " ■• " - ... J oooooooooogoooooooooool N f) « o « r- H--H^BMSMe*0JM«»aieui»Snrirtl PQOOOOHH' ■ * I > I* I I ■ i. * I I I I I IJ l«il OO000o50h999»»«9 »a»9SoS:$Sal 99S99J 999999999r^'H<-«H-4rH>-< f-4rH-^rH_-« ,H 1 s: t» -s il • o a as I- • o " H a o - £3 Is ■ o SS3SS35SSS8S3 p-ggooogooogoo do d d d d 1 t 9 3gss^s°sass;;s| M z s • 8 a83SSs:»33S23S; 2 8°83SS°fiSS5SS i ' °ssatsass3sas;5 OMOOOO-^MOOrHi-t o O 1 se8s°s°asss8s d<-IO e~aoa>cur^one».H»(Oio»H ss s • 3 " 2 s s 3 5 a 3 ji • s a a . S8 S SS n o o o o o t s saa S3 8§5s O 0'4'4 oo ^o^o < asssssss^ssass Or^OO-HOOOOOMOOW A h SSgS88;JS%3S3SSf!a ^ ondMndddd-i<-4dooOH • S8£BeSS8SSSS«S8S nioNMc>NOMN3nowniOM 9 5S§3S8ESSSa88SS3 w-^^or»«*rtOrH-«ooe^«>o i 85 SgSSS^^SSSSS ort rto*oo-#ooo-^nn sassss3s:sss8S!;3 0-H00*^O0«0O0«HO 83 53 S5 §SSS5 X oo -1 O -4 O O O O O .H .F< ** 8S S S S 8 •s O o o o o o s sag >> O --I o o g S SS 8 o -> o o o a § a -s OOOOOOoSOi-lr-l I't' 1 1 1 I ooooooogOo-^»o»»(»» 82 V m a r^ • M O o • re « o • •• as £3 S-3 " .. .. 1 SgS3SS*SS8;!3eSSSSS888S3S^ 3 53*388833333X333 asaasSSS ooojsgooooogooopojgojggo ooo d dodd ddd 1 °S5a§eaS8aSS3S°8S88°8R°8° °^od>HoddootOrHO odoo iho o s S.°gq3SSeaSSSSSS888a33§SS8 °^ddH»dddor4dd'-I«'Hddd-^«jdd-^ d jQ ^^S^,a2gSS3S^S8S^SSS^S8S:;S ***'ddHdr^ddMc^Mnd^«dd«^do'dd A 2 ".3°S5Sag88P5aS°SS88SSgS3£ 3 ^°.33^3i;e38S5S3^88Se83^8SS ""^ddddd^Mdd'^dddd-Hddwc^dMd ^ i •SS°gS8 8°8e8SS38SaSS°°SSS 6 S.Ss;SSgS85SS83S8SaSa8°g2°8 *''^d-4ddddd.H-^^d«d^.H«dd dd d •> O °°S3°&'='Jt3S833SfSa3 3S°SSS8 ^drH d rtdoAAodGonO'io d d ta d o c s °'^ooooonoK))ooaoooooooao«3oo ooooNO ^ d oooooooooooop-oooooooooqoo d d d d d o^ooosoooMooc-oooooooooooa o o o o o Sd'sfsss^sssaaBsassisssssss ||SS333 3S3S|SSggSgsi|SS88 I'. 3 . • — as L^ O O ig SI 1° (7.501 la.oa u.99 11.97 18.99 U.73 >-» gOJgOOJSg . d d d o o o 1 E 9 383S°S!!°3° o o o o -« o o sssaasssss r^ddd-^^•o-^o a 83?SSSSa38 ,^ddr4^^dddo C a 3as3S3a53S d«dd<-4d«>fl:i3 •« asESSKSSss dddddt^wddd a aiias5°°388 k ^ ^ d d M M O s ssas°s2ss d d ■i d do^o Add 1 O000MO£:OO O *> d o 1 8 • ^oooooooo' o o S8£SS8S8SS SSS£^8^^g8 o9Saao(>i>9» •ii 3 : r: iS h 1 1 » • 1 i o O Vssao 3S3S;( 335°° d d o 8»»8S ••' " SS8S2 d d d « d *^^3P ^ f4 -4 O '4 °a5ss « d 9 d d d d 9 c^ a a s 8 s d d n iH '^ 8828° d M d o s 3°°°» « ■ m a °JS°S 6 A rf aggoo d d "323SS -- 0( (0 ■♦ rf: :y '•s • o a M M • ! ° ' 1 S"" • Q •» o -- • 'ssteassasasas, 5!.. ssij^issaaiasa:; 1 ■S88°°C°°»°a° o o o o o • 1 } 8l!883«e5SSa»°i MOO«O«'400f«'4 8832383333332 S%3a383S38SS8 1 , 5 "-'*"- a *-"■•" -^ s °SS38SSfea398°i ...^'^^•^■^■^■=':"^''^.l a I 38SS;;3i:S83S38' "^ ) •H^ddddddd^'j^d 8SSa88°a88^;lS ^Se8^S8838Sg: 8ar°s°?88ssg '« d iH d ^ r4 « d r4 rH I a°S38d°S°8°S * d dddd .H H di „ 6 m « ' Ml £ I SE°8°°3S_38^3| * .^ <-4 -4 d ddd^dd. "3 - ••! ' I >, ' Q n O O O M 9 Q O « A^ ' (k. dd ddddrHf^di* 'I s m e i ■ n«q«»>a}9 :! >-ie«r^«a3Ct^ w9Q^Mq| 9999999 99»989{ \l I-: ' S I. s i fr i o •I ii ti • * aa a> *. • e .- s- I A tm I . ►•• J- 3- |8 ll !i II • •• 1 1 c 9 .a E 1 d £ ess 833 SS8°| do d «»83| o « d • 8838 d r> d d 8BS» d -i ^ > i ?8d8i 1 s:;ai 'SS| ^S3 d -4 >4 33' d f^ '3i .!!« 88°; d d I 233SJ « vl « o I 9 9 9 9 1 IS 3c i 3 V8S3 |£ I a-S3 I: i t b I o :S w -• o o Si ii St da a . 33 1 ■ 5! ! 9^88 -40 d 58^8 3 do iH v> 88 a 3 dd -4 d °S88 SSdd I 3 S3 do .^ d >8Sd 3888° o r4 d o d d °"S° s ! 5 3h 338 odd 3 5 3 3 3 O » » tt o| I, |i3S«8dl8 |» I iaxiisi , T8 3'3 8°°"S 1 dddd -4 ' '5 333^83 r^O O A O ^4 «4 J I if SI ii St e j sa • g m — a o IS <3s:3a8S « '^ a « o ^ o 8 3 8 3 3 3 a d « « O M ^4 « oaSS3K8 9 »■ n M « a ,ifd3S53 !Sg883°| ssqsaas 6 m ^J4,^o 6 X , o* d d d m i S°3°8°S If d d d o V I on o B rt w a c^ e^ i 9-^ o ) o c-o a a 05 I o o A0^9C900 ' r> o '4 i-i o ^ O O 3 O ^ a^ O n ^ K « o e>- ^ d d o o •-< ca 8^38^388 09ai-« A A r> J -4 M A « A « I ^ ^ ^ ^ ^ r*\ 9 9 9 9 9 9 I 1: i O ''\ sS a K o •• St • • ;2a CE A s- 8b C O ■ o £3 3 1 "i t 9 as9 !:S3 333° d d d d ^d 3823 d ^ »> d E d M -4 A i 3388 S3S "38 1 S38 -t * ■# i M .4 .H i 1 « s : 1 19U-13: I : 1913-U: O.M \ 0.90 : : 0,40 : 1914-lS'. O.SS : : : O.M 1 1916-U: 1 0.31 : 0.07 : 1916-17: 0.18 : ;, it A • i o •• o :* ** s 8 c 83 I? •• U m o cs aa m -• A ll |l • - o ■ 15 c • SS;35sVssSdC V :5::3a83S!Ja5S " ^ .. - „ - , S338°»3»°° 0000 M j 1 38°39"saa5;s -HO -40 OOOAO 1 88:3^8^38382 «0-4'*OAOOOO-4 E ss&sassassS' s 0)0-40-43 fflA«-4« d °ssas8ae8sai AA»>OMA«t-3A 9 sssssjssess 0«Affle-A-400AN i S3SES£°SSS" OOOMMA WOO-4 i gS?9£SaS833 dd<-4-tddoH«oo ** 338S°S°8a5S OAOO ^ ^^-^O •• « 00-ooogoggj, 00 000-4 « 1 °33°38="3KS? 0-4 00 000-41 .. „ „ ' X '■8;!S°a='°£SSl s 000 t S23asr:2S8a8:| • 1 2 sSsisssssis: - -• ^ ^ .. „ „- se a n 2« I 8 P .H (D • ■ (VI d - i j a 15 i sss £>4 3;! r • s CI A. 1 38«»» odd *• 1 88° 8" -HO ^ b i jit 3 sassa ■^ ^ (O ts* d 1 ^8338 8t 2 aK88» d M « d Sj3 s *-> ssa^s S ^ d W * d i •-I rt -t M d d o r. I i z I 3* d d * ' 3.» o S o ^ --4 <-! lO eg to tf) O 3 O n (O O N M rt N » (O d n d d I I M M o ' « o N o •-« ' "d §■ I o o c d o '^ _■ ^ N N I « S> O □ e« w it o 65 as. %' ** a •^ o SSf:g3SSd338SS3JgSSaSSS ssssisassdssadgsaasass 1 1 i 3SslS°°S°°°°o°S°d°°°°S8 6606 d d^d 00 1 55S!8aa3ssa;3:38°a883°saa8i ■E 9 8 3 s £ a s s e s g s s e s ^ s s| s 8 a 5 8 u s ssassisgassssssssasssiss lOrHddwfH'^ddd^ddnoiowto'OOOO .0 £ S5Sa5!aSgS;S3g°aS5 83g8 3 8 1 SgSS8gS3SSSSS5S8SS3&SS drtdrjddd^r^de^dHoor^O'-fMWrto i S8gsss°sesasssa35S°°3S i 3 3 s asas g 8 s aa a ss s 3 s ° a a ° d4dr^r^ddM«oow.- 9 ooj'^S* ♦• o II 1-^ £» 1^ si S 8 3 8 S « ' »S8a° d d d 1 1.50 0.50 o.ao 8.43 0.49 ■c n 3 1 ^°88^ d 'H ^ d d 3 33 8S; d eg e^ r^ n 33588 d ^ d d eg SSR3S °"aa8 8 2.25 0.47 3.10 5.44 7.15 i 0.98 5.88 1.41 8.00 *> s g ° a ° d M -H Q 1 1 03 c 1 1 P 0.70 0.27 1 1 1 1 8 a a 1 « . 1911-18 1912-13 ; 1913-14 : 1914-19 : 1915-15 I? 10 t* it - o a o 5« a. '* o « a. 3 "A d d S 9 :» V a tg 13 I 53 . I 33 I j od I sa I • SB rt d 83 i ■'St o ^ n sss; o o ol I ! ° I 3 O o| 6 223 •8- II I 8SS2g S 3aSSS«='»83 SS 3 SS83 SS!3s| I : i ^38 o o o m o as ' Q • >S3?s s 3 sassssssn s s s d sssa si^ss 8S3SS 3 8S3!iS33S8^S8^SSc;3 3 8SSS S8S^ 88388 3 SSSS83S ^83 S^SiSS 8 SSeS 8S8S SSSgg 2 88SSS3S8gS 8835 S; £888 8S88 ^- r> H M to 28S8° 3 SS38S8°3S .* 88 S sss O O O 5§S S 3 ssssggga °° > o o « ^ o S8 °5 MM ri S8 ass 8S °° OOO o o a 8 °3 S8 _ O rH M n ^ « tCkOQOOOC ?? 8g3d"S3a5; i&ss8ss: :S283SS offlg2*S3»»SSSSS32223222S323S33S2*23*** •H ^ t. a o o •> o o §55 SS 51 -4 S = 8 ^ ^1 ?" • o ^s S3 e . flS s v 8 : jl se 5i m • ■ 5 : S8888SSS8:3S aR38«'ji» jssa s o 5 d ir °^8S8 a 3 •4 d d -H d d « 3S8J38?83Xe o^dddo^^^^^ s 88^^3S8SK8S dndnMMOMnMH S8S8a8855SS c>-^on-4c- » •# r4 9 t- >- o ■ 1". !"'"s^a3s o • m e^ w d n ^ d d t n N A « (D i i 1 i. a. i . 88&°° odd ^.^il 1 oosoosasia d d 2 d ? o 1 o 1 i 1 u s s 1 Q A O AO •-4 O -i Q i h 1 '- 1 d d ^4^ ^ ^ r^ 8 o it < ■o as o o » ^- •-< O K ^ 3 « O O s° incooor^oSMO s d :< W <-! ^ sss 1 *» m y 838 JS ^C^OQC^MMOe^ *MC-S»O0»OP; •-tO'ifaeftodnv 3 3 fss ^ sags .»■ Xg"S83Sa3 ■5 I'i £ dd«d_: g& £ nn «<#^t-N«) O If. 3 OQ O OQ «» e m p- n li 9 SS=S?SS£S ^ -ii ^ A O O 9 S5 a>o o«-^c'no i §°53S 1 ggaoaagg o i a. M MOM ■ ■- ■• o -4 rt d ^ 3 c n -4 M c^ i ^ ^ d d s d "1 - J googo ."■ 90«o-i.'0oe> n M o » or o s •« o r- O -H rs ^ ^ ^ ^ n i Ijooo o d d a. °ss°a=3= r* d d d o d •* og^og d d d 1 ^^ 5 s = « > o d d ^ o aioQo o- 3 O o . >• - ooggosaa d d o< c:^^ S2S2S5S sg 322^22832 -: O o o ■ j M n ♦ 2 H d zi .*.. ..^.«».«_.^ «.. OB I « ^ <» fr- il I 8338 O tn ■ N 8«- a o 2« IJ ; , ! 888° 1^ 1 odd 1 1 38SS j ~ d d >^ 1 S 1 Sggg ■* ' M O z 3 sass d M W<-< i SSSg £ 3 "* ■* 0) 1 5£S5g| -^"--a ^ SSSSd 2 N d w n d! 1 5SS8 -"-1 .. o o >.• o « OM o M r4 ^ « O O o o « 8e°3 1 ■ o o o !l agoo d * M ^ ^C « 8 a 1 1 -* M n •* O • -• 83 9 CO Is «* I. « O ts f : a o = 8 fJ 1 ssassssss M ; <^o o o g o o 1 d d 1 . 1 1 !sgSS3g3S3 rHiOo• 1 8 m a ='8a°SS°3 -id d d d oo^oo«o« o do 3 2 2 ^" 2 • 8 s a 8 =222=2=225 :3 Si I I e3 la a" r cc •'^<»''^3( I0 3 >00330 7000 S''888SSSP'"'C3£3B °aS3S838SS88°e8S A 4n r^ o Mr^ M n o ^ n n vi AMnMOOyt^MMQtAIOnt-N g |M«>S(D<-«OHP>0>-40m(0^n» 8! 30°s°8SS8e8S5aas rH n o M M r-i o o'n •-« O S3aa°8°°3°°»g508 o o o o o ^ OB 'ii II oooooooooooogoc ooooooooogg j^g®"! I ! I d o 2^ °A I •^ ' OOOOOOOOOOOo 9 o ■■ f^ n - o m a *> o Z% OOOOOOOOf -^"T I , t A A J^ A A i « o «t SB i ^ ;d 2 2 ? ©d 223S| ► OOOOdOOQC 33 1 s-'aaas-SBiisaass^aas oogoooooooj^ooOoogooo i ° 8° » 3° 883335°°° 868 83 1 °°°8°8e8aa8C°33g88«3 ^ dvio^Moo o^^d«i^d 1 8SS888i;88^338Ss83CS8 2 sassassasssxssgoBggg 9 838SS83K^8e338a°gsSS 2 8J3a°38°8a3S883gogsa i KOESssa-osassss-asss •* SS°S°38SS888 3°sasSS<' HH o dododowo .;d^d.H i & "s t OOOOOOOBOggOgOojoOOO d do d ^ o -^ o* 2 >> ;3 oooooogooooooogoooeoio' o "d d o a M o • h SC*SS88ag88888S38 s^aaaaaasasaaais II r oaooooooooogo gog d d d 15 1 8"3^a8338^8<""'88 n d^dddoomo o^ 1? o •• J d ^ -^dd^w^rto^ d S dddH o n o r: •• « 1 oeoooeogogogooo do 6 '^ 6 QOO^PQOOOgOOOOO d « d d d •• 2^ 1 OMooaaoooogooooo d d d a 3 S a23Sss33ijaa8S8st a 5 52 -H«oiOrHooqoc»oopoioSc-8"»« 32 ; oot^mOHi lou) to 9(000 ««wMi 'Old o odi-iN oooo> ! ^ ..8 J5 r. ^ lOnpjoiioooNooooo oor-ii-i SON C-O««^e-0t0>.-4OC>.OrH COV>^ II ! i Sa 2J! <ai39ooo uo I- is asssaisdsaa 1..^... 1 ■JO o o-oo a g o u a^ o do do r^ dd H e "sa^.geasssss" n d « r-^ vin n «3 r^ « iH 9 8SSSSS8S888S .-4 c^ d <4 «rt d d rt m « o a a33S°8t)SS3J i se§sss3as|38 88°8°SSS8SE dr^ N d^^oo-H •> go^ooogoaoS d d d •-* o « o o g pjo a o o ^ o o d d O o googjogoggo o' o d o ' o o 8 S235SSS28aSaS iaasss^^s^ssiS O sdsaass 5)253382 . joooogo d d 1 S8''8S;^R HO t^ d d '^ 9 •°S33gS o o it o n -H •• .1. £ 33:^8383 rt -^ • rt o o o d « MM t^ d o 9 S C 8 3 " a 8 O O M t- •» « a d d <^ IS -# i ^d 6 A M o o oo o o o d « f 8 • ooggojo d d d o o o o « o o o o S S S 8 ^ » »: T!*]! 1 ^ T! ^ ^ S3 a ass 6 s O no « B lO «M o ? : £5 1 o oooo o i ^ •< oooogo o oo o o o 2 8 388 63 r^ d J d M «4 58°888 O rH ^ O -t 9 1 "^ saas,ss d d r) n M M 1 i 8888°8 « (O O M W e z S°8S° , d «d d i s°°asa d rH d d *> • o o o o o O o o o o o o >• a s m o o o o o o 4 W) « o o » 9 Ok » Ok 3 9 n ^ n « ^- 0) ffi ffl 0} o m (D 5 I ^ Q e^ « • •; I M a Q o S3 Ill a O ►■ .11 V •* 38 a a I l8°°S S°S' • o o •» ■^ I M O ^ O n ^ o o O ^ Od ■) Q O O •HO O f ! 8 ':3 i I » O O Co o •• fc CO p 1 *S *83S8SRSS ■*■ saaasass 00M0009D o o d 1^ 3 O O M (H o d 1 ^ 8 88;>SX»!SS 5 sssssssa A « S 588&3S8S o n9o-4r4«a)d i s sssassss o •Hodvioioein s q 88S8'='°S8 1 S 38a°SS° o o o r^ o M « o o o o o o o o 1 IS 1 i i! oo oooooo d d OMOOOOOO d • 9 8S It d3 it (0 •« a o l^ ^ ■ PS IS m o S!8 oo ^ 1 »)■■■ cis t fl" * n -a 8? s pa s 8S S8 a O* i 8. d 3 s O « O i « 8** 1 d 1 o oi " ' " n «> c^ '^'T'T 8 4^o) a- a oi X -- — { iS 4* ll II S-3 IJ S « S 8 o! X S X ? 3 & 3 IS 3 :33sd°38Sia333ia 83''8S°8°aaa'='°3s oo JO o ooo do S3SS<»°S8?38i5S38 OONO OOOOON^dd sssssjRacssess?; 3'400-IMn iiliiYiltiiiiii 82 §1 I? s . a o t 8 a. -1 1 • as 3 08° o d J 1 c 8 S8° o do r. sss -^ o o .^ i; i • s s 3 388 O d«H^ 8 S:iS o d d -^ •J * w i do d H o °i? S8 ■« N d go ao « o oo 1 o oo 8' sssss nils □ ^h; o *> Q fl m C to a o a e > 1 = :s; i4 IS sir St i« o m f ■"" 1-' 3°> |2 n > a a I A o o q X I «> MM X , d ^ H sgss ^ •■ d d So c^ n O « 00 I n M ^ «> • 9 « M ^ 9 ! d « e^ « se^ S3°8 OH n ggogfi NO O O o o o o s 3 O O O O «3 • i M cv A n mI 8 3g i I i° i I *• o £5 I? E2 §-• a o o H « d M d; i dsa ra 03 o as d M ' « • o o « dl ^^! II 1 oo. !l 1 8 • 332 rt * rt 1 9 9 O 1 g^ a3S3aa"S'-'sl o s : « H |t e o Si a o 5« ■^ oooooooooo 1 OOQOC^OOOOO d N d 8888S3°Ea° OOOOOO oo s ggg88SSS3g ddrHododrnn-i 8SaB8S8S°S rHr-l^a}NnOH ■* OMimooQooMn ^r-9>HC-N(DM^9 tOHrtd'HWooweQ 1 ssssagssqs i S8S88SS°SS oin-io'dNd (Hi-*. i asse^ggsas? d d n d d d d d n *> ? CO oooooooooo •4 oooooooooo ■J oooooooooo a g c^ 1 i ^ A A i A i n o 5-3 II ?. .. 1 5S8SS3 a:^:i33a oo O O O OO ! d d •» • « o if 65 33 1 3 O OO O d H d wd « .a A.. s. ^ s s 8 s a a a ^Oi-fNdddd essssssE i 35!°°$33 >« M d d ■« 3 oa i JS°S2°° ei A N d "k d d d d do rr O If la" i • " i f o o £: o oo N rt o d d o o o o n o ol d • 1 •> o "S II 1 oo ooo ool a 1 o w in .. . I_ t OO^IOOOOO Z '■ 03 s°3a3°«a O H o o o •-< oodnoooo nHM3 NMH>-I nc-o ^ooc^Q oa>onQQb '4iooonovwcj od^d^-^oo 6<-tQ}03HMr) «30C>S>OQ-^C4 s 1^ SS8 Si2 d33 n 1 = 83 d d 1 1 KS3 • ' >! .H s t 9 ^'S3 «0 -H ■i 1 3:^S a o oo H » 5S° ** z rt * ss 9 sssa St N -t * O cs pj « ^* 33 « -i R SS3S -H M d o ,„ 1 a ■ .; 3gS3 — m o O 3 w o u •* • • o Hi Ji o iiS H « °:3°8 rii O O rt O n .^ o ' '1 'i i .i .1 ,^1 .•x . '-:' .. as ■8 5 is S3 as £5 'j H 3 W tfl -^ a odJ^'^o^o 88°° 888 « H Ki eg H i 28°SS° S ^ O O .H O o SS°8SSa do d d rH o s o o ago o o o o 1 o o o o go o d 3 g « o oo o oo o «• o Sd gfr ia" «* a • o 1 ooo "go ° o o ^ ooogaas O O O 3 8°J 838?! ■< o o -< o o ^ ^ sssssss 3 .,00 oo o ot 1 i s»s°ssa k. M^n w M n s S8S 3853 N O M O ^ n lO i SaR8°S8 d MO ^ ON 6 83? SSS£:i H lo d d d .H -H J 3es a3°g O on-1 oo rf °g° a°°s do o OOO o g] o o 4 d ^ <='°'' 583*^ J ooo s Saa 3233 S S 9 o. o o 0> Is o d£9 « o 93 Ci :8 i ! too M«9*>Ol(>« nooq^^t^MO oooooofeoo •HO d ■^ 9 d 8=" 33d8S:S3 o o<-t^3^od S);3SS8S^3 d d M#HMMM«H sssassass 3 nr4M^«MDW ssssasasa e°asasa8f. I O OOIONO^O s3S°8 O Q O O M O O S9SS3S8°e ddddddd <-4 o o oooo»oo ooooooooo O OOAOOOOO <»0 rH«rt^J)Hr-tv4^4 s J « o " >t 3 3 St a . o « Is • o i3 Seasonal; Total 5S 33 M 8=«8 o d II d d .a i; s 8SS ^ d rH ^ s s s N 9 r-J N -r cj •»• d o 51X3 N ,-i tfi 1 1.' ■* i a. 3 g° d d 1 i°S8°2 ^ . o o d a ooo » Ot O. Oi o. I* •• o ia n o • a o: Is 9.30* 10.35 16.35 ^ o o o o 1 1 1 1 O O O »i ^ d i 9 3°SE: N O ^ .a SS°S; « d -H t W fO -»■ i °S3S r^ ■* Irt s d ^ 1 §S3 d -H ^' o O O Q o* p. s ooo 1 ooo 0. •-) 3SS9i 3323' t: SSe§SaSSSSsss3 33SS835:8SSS: "S^saaaassa'ss '*sa'°'^s3'°'d33; '' 9 r* O O M ■ ?• ^6 tas aO lO o o N 9 .H d O O O °S23SSI8Sg8?sSa8 gSK«SSS3g°°3SS cgoMotoooioo^^dr^n d^-lMiHfHd^wrt ^-^w OgOOOOiOiOtOigoottlO <(»M*OOOOOOlOmOO -* >-* •* ^ vi OtO ^»H^»HnO OWrH OOrHO <-• rtr-l .HfJ 3Sa8S°88°3aS°8 ogooggoooooggo 00000 00 •Hq^^ d O^ OM ooooggoooOoo^o onooooQOoooooo 000 d d .H o g_ OOOOOOOOOOq^OO 0O0O0003O0J0O0 )OOOoooooqqo^o 0000000 0000000 B .? ooooooooo >»»<:* <» 9 S> 9 O 9 » t> a » » » 9 B£ m p 88 « O ss 23 • a Si £3 r- Oi * P- O rt \n N ^ t> >o ^ a°3S°8 d d d d o o o « ID m .H n o K O O O f4 a p- 9 at >i -^ (0 o o o ■■ asasjg r4 O M O O N d '^ d H d .^ O O O O iH ■* 33833° I <-4 r^ CO M N O p- o r- q A < to o « 9 3 O r-l O r-t O S8;)8S° o ■« d do ooogog d d 000000 000000 8 S S S 3 ? I I I I I I ^ H^dn^ dNd<-«Mddd .3 i 3EJa»SS8SRS°3^SSSSXS8 5 S3 ESSS 58883^3838 SSe (a0rj«.400cgi0-40 0300rH*d-H* a a3S°S{!?SS8SS8SS="'88 i 3S83SSSdSSSSgg3°Sffl° ^ ^ J d -H d d d d 3 d -H D d -4 -^ « o 5'=S3S3JS8S8gS!S3°SSS, -4 H00rH0M0 0*0-«dcg0 dd>H OO90««g-l0C>00O0M^OOO oooooo oo « 1 oojo^oogoggooogoogo o o odd d d . K 8 « oo»>oooooo>HOooooooo o; O 3 3 3 S ^' S ?; r' ^ S 8 S 8 S S S S S S 8 3 8m 1 «sada'-'»a*3;:^*"3S3*3aaa II »»oooooooogo googooo og ad d d d d 15 1 8 a as 335 38 3°° 8° 85° 35° S dd-idodooMO o oo *»o o t 9 8;?83S°8SajS888e8S88S3 d-^MON 3d00'H<-4«aP-'4300'40-4 lit «S35!;8Se«aag8 3SSS3858 -^d'H-^d«J^*H«irHWoio«o-Hnoo'o Mnd-^MN-^ndMM dM«o.^on«o 33S^.^38SS«3 38SaSS^S^3 r4«d3^Mdd««dNdd'^dd-^-«Md^ aa J? [ g6^8°aSSSSgS8358°=>88 1 -Hoin-H -H-lOOMrH-Hr-l«*OI rt« 3! « i 85SS5^S838ag8SJS°SS° N-^nddwdd OHodoooo ^w •* a o « 1 00n«09S0<-(0QO0000^O«O o 6 6 d '^ 6 6 6 oogoo^oogosgojoooo^og d d 6 6 6 6 6 6 25 ■ — Z £1 8 I > I A I S MOOHOOaOOQOOOOOOQOOOOj odd 23asJis?isfi?iss8SESS»sasJ! t 1 I I I I I I I I t I I J I I n • S t-i in £> M d (D <» o ■^ * * w d d « «0«^ ..-H . ! OO O « OJO o d d ! 1 OOOJOg^ 3 3 3 Is t * ° s s a a s P d d « 3 o ^ 8> e 3d- J3 s sasases pi 3 d d d d o 51 g 5 ° e a Si w d d N w pi Ii 31 n M M d 3 •« -^ SS8S°SS d d d i-t 3 0* 1 ^ o S 3 S o aji ,H cj I)* d « o r. =-• o 8°£SS°a d d 3 o A\ >• is" g| !i 1! « 8 1 1 gOOQOOg, 3 6 6 M O oo AO O d d , f o o o o o o o> i o '^ 2J 2 ii Si O 'H -H , , I 1 l3S2 = S3| ^ " " HI £3 s- iS ^s . S3 8 a O 3 3 1 3S sass; 3 3 3 O O N ^ o t: 9 es °S5^ 1 O^ O O 3 1' Cf 2 SSS 883^ -s.. a OO ^ ^ « n rH s^f^ o $25 8Sgg s. -H « O ^ -^ rt 3 gjf 3 Rrt ID t> S lO t' n « c- -H 3 J w aa S MM O i at i A i-< rH 3 d -J -H 3 CD - *; §=* 8 $ ■ ^ O 3 O M OS a s d o is 1 "^ 3 55 g| 3 9 oo o -3 *««p-qw aH 8 n S SE gS St r. 8>: O (H Is gi 3 si 8a2SSSa£.SSS8aSS33SSSS8£SSS388S33SasSS3S3 ■*ewM<»Hdd^dt^inddp-ddddddNdH':i'^2^5^'D»H«)5(»>-iiHMndwddo oJd«d^dd'#d'^°'^*'*'''^ ^oomw-H-HO^n SS83SS°S3SSS83a''°S88SS?8SSSS°8SS;aS3SSja 4 rtHodoId^'^''*®'^ d«03ooodrH00 N00300 r-<.HOO' SS°S388SS8°^S33S»S8SS°8 8g°8°SasgS33gS8as 6 oa 6 6 6 6 6 6 fi 6666666 6A6 .h°o ^ •-»B-n«oooHoooooooooooe-oo ^3 O O O O rH « ^ sddd d d o6 OjmOOifOOOOjDOOO OOO 0-HOOO«00000000000<»OOOW0 55S30*SOOOOOOOOOOO O ^ O » f* o ,S , . d 6 6 6 6 ooooo ' w n ^ n « t* (D 9 o •-• M p> « o «> c- a o (-1 M n « n «^ (D»o--(j».j-4NNMoiM oaoa9»»90>3aoooQOoooaQi-<<^ > • i » '•'_''' ' '. _l''J Tilt I I I II I I I I 111 I 1 iTTii-iW(0i#o«P' ---*■ — - -"■ -_- ... ^ __ -- --i<;>.,_.^_<^,^,-«^.-i;;r>j,jr;MCilwf» riitliiiiiiliiTiiiiTTi. }9dc>ao-4oi^«>inOOOOQOOOOO- 13)a>a>(oa](i>9<:*aa90o>99oc s 1 1 S i i m n a r. I' t% u li -■ •• •J • 1 o ;:3 P • • • • • ■ 38SS3SS-; aa°aaaia ! O -4 O 9 3 O sooooogg 1 saass ' > ^ -4 9 5S0=38e8 a -' n ' N 10 d o i ■^ ^ 13 O CQ O e*. O P" P- t^ N .H to rt ' saggggss n N ' r^ .- f m ■ i « M 3 'H <4 l£?S-«no^co i 8°83P ^ lO « N ■« ♦> ^ 1 4* o 8CSSS O* O ^ O r4 WO - o a i a 1 i °g8S° odd oooaoooo i « 1 ' s o goo _ .■^ oooooooo O O O O 1 o o o •J I • 1916-17 1917-18 1918-19 1919-20 1920-21 1921-22 1922-23 1923-24 1 1 1 1 1 I I t 1 1 ^ in n t- (D90'^eu« 3 S ,g3 8m Is* •^rj"'2"3ssaaa33'-28ijsa'*s3a3'*3a03°s3s3 ; I ; t I-! s s .s Is O 3 ^OOOOtfJOOO^ NHH00060000QOOO'#00000« o ^ddo J do o 5aS8a88838°°S88SS53SK88°°°''8£°S3''S r^oooOfHOooo Jd*o<-«dddddNd <^d «d o Rea'?.ssessssasass°s°S8as8SSE:g°s«a3S i-l03-(00'-4OOO0'4ri^^^. M d>HOOr4MMaiM OOMQM IMMOOTOOVIOOO I, -J -^ Stf d3 6S ::8 fc! 4 °SSEi8S8S;saSodS85S885S3S°SXaS,^S85!S' oMNwc-NOtoNo^ nnoNrtw-^^on-H owww to«>oo 88 JS3SS'JK5SSsg8sssSa£8SSS8S3£ . JSXa to -H O O W - .>om-^oo.hoo.hof^'H wn SSSS3aa°SSgSsj''8°S°SSSS8S^33°8''S88 300;>000 rHOOO, r4 Or^OOOOOOO iH 00^4 0'^OOnOnNO'HOOooonO»OOC-C4CaO«OOOHOOOOO) ^ [ o o oo o 6 o o dd^ d ^ d d « h i 2 ! O00O0OO000a^0o^go(DMO;PO000O900O0O0itLiiAa223asr;22sss;;-58S£8aon3' • • o e a o :4 a bo 11 p . ! 1 1 ssssss "'""ass's gogoogo o o d 1 S°°SS°3 d rt o -^ 1 2°asss£° ^ r4 J ^ d .H J3 • It 9 S«5S'='8°§ N d w n 3 -I • o rt ■* « ^ r^ n o a i 88°°S38 W -H * CO M M m o <# o] o oi .H d « « o i E:g°38S8 A o o o -^ o •• p. O O J o o o o o « 1 O O O 3 OJ O O d ! " " ' ' '■ O O O O O O o ESSSSSSS 99999990 ^ (OO t^ «« S^ oo .u. , ^ 1 » e09 1 od ^ 8. t ss s it wo D .* J3 s ts OH >* h:: n o x> es no a >% rt • o 1 :3£ Hi in» J £S s W©l i ss ^ OH a « HO (0 O H H m -> . « ^ °g3 L^ If, 3- « ? °.°. s . ^ o o 1 oog o ■ — H i^ a 9 9 9 . « s s n §3 o o SeggS£3SS9SS£83S3SSSSS;jaS8S S3^3^s33as:^'-'3a'*aaa»sa'°'aasd 03000088°°° °°°°o°S°£o 8" °°°8S o o 000 •8S°°°33SS3 3a3S8S°SSa83°SS^3 Jdd HOOHO dd ^dioo ooooo «o :> 5Se°SS33S?S8°S£a398S3SaS§SS8 woo 00 moohoh dooo- H 0) O M to C isssssssa 10 M 01 M r' H C-00 3HO*HrtHWO'#HO'*OHnOOO S?SSSK°SSSSJ$3Ss!SSo?SSgSSS^3 inoNdidto towiod mh caddww drt90Ho«»n3 d-*-#nH« 3HN^9-#H ddeJdwddd 30h-#*«^ «o ^o'-*3'-'« Hi-to a 91 s: ■ o • ■• as I- - H a o - - ■♦ l! ii £3 1^1 -ass "as a s 8 5 1 oogj O- -.-<. ssssBs a i S8J3 "^S"*. 8S i ooj- SJSS" S3 •* goo S-g»S 8S ° ^ o .; .;d •* s 3 °S5° "^°8 ° do ° ° do a 1 1 a i • o to oooo aaooo ° fl i' « i P-* « • O ooooS 'JLJ.JIJIJJL2 3 £ 8 (? as 3'. • a SS 2: £3 1 J •338 j3 o oo oo i 1 9 33888 -4 o d -4 d sassds M d ^ N O ^ £ 3-°~^o- i s"8sa d jdg i -4 M n i ssss d« d -I o O o d •> o o o « 1 — o o rt d o o o 5 d 8 n I.J.. S2 3 335; -i 01 f4 ■♦ 2 « M • • •• ■3S ■ i d:3 n o d a • -4 -4 *- I I |s2 as I.- a.- a o £3 33 33*!!aaasss '22 oooooooooo ooo '"»8SSS!8°°S "58 5!88aSS8°8S' °SS d'HOOMO'^ d^ 04.^ M M M d M .4 n A d d ■« d e ^t>'4MA^OO«0 vFo OQQOp»>OMMO 0«0 8onO$«^«9« OQM o o o wo o o oooo ooo d I oooooooooo ooo oooooooooo ooo OOQOOOOO^rJ^^^W iiTiiiiiiiiiii >HMr}«oer^aj90wMA^ OOOOOOOOOiHrH'HrHW s • o S s d do » s i 8S t h il :s aa i s a i. ** O 8 f S° d 38 d 9 S3 M n «8 -4 O 8° O .«: i d u m — £3 1 « 8 O w^ o oi 333 23S 9 H ~ .8 • O ■ • o as a.- 2! 25 53 ssssssssssssss n ooiooa)-*«>i»-#oo«t^(0 ,> s o o-b OOOOOOOOOO o d d t WMO O O O ^ rH o o o o 3 28SSSSgSSSS°SS ^rt^M^ooo-^oo oo 1 S§SaS5S8S3S?SS ^c-owo -^-^oowc-rH-^rt 1 d 1 • SSaS5a3S33SSSS 1 ^ waOu^r-ioieiOA-10'40 — .- " i SSXS°SXS2^5SS? 1 " o-^ot^ rtw«o-«wow-H 1 assssssxssassa OM003rt*a3NN'4MrtO i 3S3£S8Sa83gS°8 OOOiH-tMMOOOwO '^ J a £ S 8 a ° S S 8 ° 8 s ° s o 0-4000 OA^ oo O ? 900000'>0<-l00000 o no d do ftt 5 oooooooooooooo - o >. 000000300 ooooo • 3 „ SS^SoSoooooSoo 1 s, » £C if 8 r ■ aT- si P £3 • o o d w rt m rt ooooo « 5 O O dd 1 a='°ss°s o nod s 9 ^°3ag58° -H d d r4 o « s sasssssg Mo-inoood I 1 SS8S^5S^ r^H09a»a 2 §3 9. .. ., • £5§Sg3SSSSgRS8SS38 SI, gSS55S£gSS£3 -rj-ssadasa-x-sass^-s'si^j'aasaasaas a ooooogooooMn»oooooooo«>oaonooooe>^ '^ o doo odd oo 1 8§BSgS3S°='8S3S°SSS2a8°='°SS3°§S°S I U oooooooo ^o*dw ^ «" a S5?°S?!S5:J fO(on cgrH^nn i 8583SSS1S3 HiHOONnOOM S°S83gSSS o o ^o.ho^wo ass-'gssss OOr-« OOOOO 1 °3a°8ass8 O O OOOOO, >» s°ss?£°es' 3 o o o o o o o 3 s s J: 2 2 8 ;3 a 9 S r^*««c- <^»O^U « a: •as. o m « o £3 ^ 1- 38883888838! iB»aS8SS;^SSS i ^OOOOOOOOCIOO o o o 1 S!i.!)3383SS°°3 OlOO^OOO^O o .-4 9 8?3»°g83S38S r^nON 3^.>r4WM«l SS3SSSCSSS8S 1 O-IFlO'On^-NNM^lO ^ 8?S3C8S«8SJ e^^^Mintf^OMO.^ 9 8383SS8SSJ;S. " r^r-odo-HiodN'^r^l i 1 33a=S8S38S7 «*IO (Qr^^iO««* i ■ sKssssasxa^ '4'HOOHNOO^N ** S°83S8Sr;8°./ *> ^ MOWW^'^O o «OOOOgOQOOO O O O ^ « 1 OOOOiHOOOOOO o o o I s ooo>*n«ooooo r4 O O O sisssiiiiiis 2 t-t M O • ** ■o a ;s »> I. 3 O 37- •> a 11 s it Q o 5 ° => § S 3 S O O O rH < 3 £ S 3 S 5 d d d d -4 w ^ M ifi -H rH r^ d d d -H ss°sss o ^ n n in i •o V> o t- O N c^ ir< in (D -^ (C d d d rH ■* d s 3S a.- £3 iS5S!S8S8SSSSa8S85B:4gS»8SSaS3B83SS oo:2«a2S3S2d3'"S8Ssa2S''a''°"3a333ass oc5ooogNoooo3!aa°°°°=>o°=>a°s°°°°°°as *• dod dd OO POOOP>0<000000 5S§SSSSS8°°8SS»SSSa^SJ°°°33S' . . iHOOrHD OO O3I0O OOO lOO OOOOr-IOOO; dSSSSS§38 •a!>SSS°SSS85;8 3SS°a3SSg: O 9 ri O O «) « lA « M M « in rH 03i-»00-»:JOOOO NOrHMOr-i ^ooor^r^wt-.H JSS§SSSSSSSSSSSSSKE^S3§SS8eS:!88SS ) ^ O M ^4 Oi CJ •- 1 OC- CM « r^ Ol r inMotr^OKNOtn n^fmrHWrtoj-^QtOr OMSiH^r-IOC^O SS3SaS83SS5Sg3SSSSS5SSg 838538 SSS lA'^A-i^-i iA o o <^ -iA DowoorH*)Mr^« CJ r4 O 01 r ?5 S S " S S S 3 33 S ^ * 5 S S h" !* .h o d OOOOOJ3gJ;0 08S°oS°3°°='°°°''°°°°''8° o o o o O O O O OrHWrt^ioibc^m^o ,-1.-.^-...-.- DOOOOOOOOOiH OtaOOOAS can-«tn«t-a)oo^Mn'«v}«c^ai oo>-*<4n - - - • ■^r^r-tjQMMNCJMMMMMnnntO . . . . I I I I I t I I I I i t I I I I I N n ^ m V t' (O»o^a)r^«io«c^ ajaOr^w f-«.-4WM.««NWWWS«lO(On »a99i>»90»O99l>0>C>0i ss3SEs;xss;g5 1 Aoooo oonnooo om 00 do 1 °S8SSSS8a5§°6S »4do*dd^rHo'od A G 9 h 1 •4 SSSS333S;888833 OMOO-400.-10 r^oo dd S • « a 1! s 1 R§SSSSS8:J3S9e3 i ^ 1- a « s °8S8S358R3S ?« Is a 2„- ©0 00'«0';;»0 a»0 MO d d ooooooogogg og d d d ■i % «|JOOOOOOOO« d d ' ssss^s's'ss'sssas iiliilliiiiisF S9 si □ 3 • ■ UK u a '• • 1 t 9 a s •r>*«t- 0) a o O 3 O £38 « O ^ ??* O 3 * ai n ^ 9 j is 8 Not. O.OS o a, 1. 1 J..I s s p* n o o o o « « (v' i> o » 83 II e o d3 « I S - £3 ll • • • • assssg i^sssad i 1 1 do d^ i o o vi o o ◦ 5 .-1 ei ^ o lo n t 1 ="883885; -*o ^ -^ « rt .a £ lO A 9 -4 « « « I S88SSSS -^ a> .-j Q c^ rt d a. o C4 m 10 N n ^ A ^ .-« -H « •* o ■f a <=> E: ^ ""■ o o V) d t °- § 8 S =» S g d d o d -< ! ^ 8 S 1 « , ^ d d d d (O i" n o t-' (0 a &i fo <*• tf> lo r- IS <> ci » o. oa » S3 « « 11 8. 8fr IE • o ss EI3 ■ s a - 23 Is £2 Is' « • • jiq:; , l8°=« 1 i° 1 1 ° * t a ?8S -* d d N M d e^ rt n 9 1 i ** as? ess pI d -0 t-' ^ N o A »g3 o d 1 % a ^ o o » a o SE •I -s 8p 8» ■ O « a 11 n h 8a;idd3 1 ggoagga 1 t 9 axjasa* O O M o d o 8 E a " B ° =" Aon N 1 S 8 g 2 Sj S S o n ■# o d ssassss' '« o d d ^ d d i gssssssg Oi-IO NC-Mud i -i d d d e-' d i o * w a- 00 * 'H ^ o w d d s SgSS°gSS <« d oi d d d ^4 •* ooooooool d « OMO Offiocia O rH d 30000000 |sssssp;ss| 1 fl ,----^-.H„| 82 a o « d £J3 p. 1 a S d d 9 d d S 4 C^ 3 (C ON d rH r^ i 8 as 1 s ! ss •^ ! O J i o 2 3? tfi OrH A A o d d « o 1 >. 3 >-> o -t o 8 a a a a § II & *S888aS5SSS88?^3»88S£3S2SSSSgS8SSS32 -■sss^'-'ssssssa^-^sas2S23S33a3S33S3as 1 gooooooojjoooogggooogoooD^ogogoooaott- o o odd d -do do' . . ° 1 3388888838 '=>°°S3S83SS58Sg°='g§8»°SS='J ^ O'Hr^oooM^oo f-t d o t*o o o o o ti A dddd ^A A • u c^ ■< SSSSSSSS3S§83S3SS8g°SS3S3S38ja88SSS rj o-^oowoo.-l00ooMOo«plO« odoo..i-M^a.HOH 6mv^nninA^e*o^AN-iddd i P8SSKaS3S2SSS°SSS°8S»SgSS°S5;gSS3es8 8» oo«M^MO'«<-tn'«o« n^d deaddwdr^ ddc^r^d^dd:) s °SSSg!lSSSS8S;J£5SSSSS3SS8§2SS8SgS3SSS a3 *n««^3M^O*«««ONOo«^eg=>dr*dwdd-^dd«e^-5^«i 1 8°°a°g8a88sea'='2aa3°ass53sss2ss°°8s o M woe^oooow rnddd M^dd'^dd.nddd ^ ^ i 1 SSRS°'=q8SSg83SS8SSSSasa8SS4g«g°Sg° .H-«ooa rt«oo«rtodw-^.Hddddddddd^-4iId mm n ♦* SSaS:ja«'S?8<^28§S8^5°SSSiSi;?SSSgaX°5S? r oooooo owd ^oworH .X '^'^ ^ N d 3 d dd M d d d n s . •» OOOOaOgOOgOJgOO^OO^OOttJgO^OOOOS^OMO 8« is o oo o d d d odd d do S . Z'^ i OOgOOOOnoggQO«HOOiOOOOOgOOOOOOOOO-rO H n •* o ooo-oo o o d dd 3 OOOOOOO^OOM^Og^MO^OOnOCjJMOOOOOOOOOO o o oooodo d d d = 8 II S8gg8?gSS8S3a3"3as^2?.8aa8SS8S8SSSJ!S ||i|§i|i|||f|33S3S3»33sssssgasi|sss 2 • 5 a g II 8° So ai m m :4. 57, n t '■% OOOOOAOOOOOO .-4 1 i' ggJjOOjjOOOOgo ! 3 1 2 es^ti°ss§ss3S! 9 i i Z. •• A "s 1 8°5E:°SSgS8=*s; °SIS8SSSSSS°g| o ooooooooooo O OOOOOOOOOOO! I 5 O OOOOOOOOOOOI a • 9 c»a(»(>c)>c»<»oiO(>oi S J 3.S 82 22 I s gf St « o sa 3" §i £S f1 a 1« * £» "2 1 il 1 m -< i: «a t 9 < ^ -! s t& 5" ^ ^ Sp: » ifr «• b 9 a tS o> da . N a ■* i .3 '2 n n • o ■^ r. ,; ^ « O 1 a S9 « O «.• A. .. .. !3 ^ (D s O H iia zi 9 n i m » ca h dj as& 1 0050 .o,(S M 00 1 XS3S i;a4?^ >-* t 9 S8°e iiJSJa on r^ H «o M «i 1 • 8 se S;:8^s ^ 8 "0 d"«"~ a °8 "888 1 °»S R5°8 n 0^0 CSS •-4 O .H SS°8 ■J d d SSSS w w 'H d ;88° d d ^ d >8°8 ial^^ lO O t- O) 9 •-4 r^r^ ^ H SO •-« w rt n n n n 9 9 o o» » s .1 Vi o 8fr It it da 2-- 29 Is ii li S8 o • a I"? 3*e%f 8 8 ;::S88a3 1 gooooo m 1 S»S98 M ^ r^ 1 ssasa n -4 « -1 sS'saa a S3338 ^ «^ « «• 8 888S!g •! ri « ^ 0' i S"8S° M i 838^°! noon S^S&8 M -H i :i a M d « 1 ■ a 00 a • sssgss ..3333 33 II dd 5: O «4 2 . ..< M « n »• o en -« o «• a M O O « •- 88° d d 1 818 d •• 5 e a sea d ^ N 2 S"S « M ID S 3d8S d .4 A n i 8 " 8 a r^ 8 3S° d d S8°| « 1 50, "t 3 ! «?"; 8 1 ssas! 8S 3- 8» ■ e 9 m 2g h ■3 SKJS 1 m d i 1 " ■ ■ J3 i. s .a £ 1 1 1 ** 33S * n CM M d s?s .f w s°s S 1 8 S r^ d d J 2 list a •-« £8 h 1° 3 as •-. 52 °s do d 1 S8 83 rHO t 9 §8 as d « do a »5? S.t i d -^ ^i« 1 d d »« a g 8° i Mo d as g do d d d 1 8 a s ss ° d d d d M N n « «>c~ 1 2s3333| (O o ii? 9^- J 1 3 d 9 I 8 d £ S i ** u •J d d e 10 3 « 1 1 8 U3 5I in '4 o n a a a« .-1 I t-CoAO«>r> ^M«0 g O H K> o OOOOOn Mi-I d b d 00 ^ MNOOO °8°*88SS88 rH d n o r^ n K gS°a''8SS»8 MO ID <-« O « ^ ;• i^i Q <■»<«■ E: c> iS 9 X a o n o n o >J rH O O O M >^ n d lO lo o o S*S8»8°8SS 9 N W —t O M O °3S°="saxa°° « M M «> o n •88°S353°E n eg 'H o f-i o o OOOgOOgOOfi^ d o ^ o i ■ s n a I ,1 4 M n OQoooononmjB-o '!«£ nOQOOOOMMOP-r rH B ^ n « I ,4 r^ d M ^1 9S99950o8dd| Sioo^ a)90>HMn«| 99999000001 asssaasssss 82 I" n Ba I? *• u m o • •• as D • 23 h Is n 8 8^ CSS d 1 1 °g8 dd :3 w d 1 3»2 i M n «i s 3SS n N 9 i 8 8.38. M « e^ r4 i SS^K *• -J d i s 0000 d 1 0020J = 1 5 8 ! ^ M 0| dd 1 sssssssi d3 9 a ^2 Uh 1 ' Essssasssssss assssssaaasas , ^ oojogogooo jg3 O « O O O O a gBs^aass^ssss i F)30 OO^^O ^OOfH 1 i; s 3 s; 8 3 s s a s £ 3 a s o^<4(g«»^o^ooiHn /I 8KdSS;j»aSSS38 2 (grtcaiOMov^n-^o oo £ 3S5°ss!ssa£3sa -■•N r-^lo»lMrt-^ulrjO 1 SSSSSSSSSSSSS : n«(oooo^O(oainN.H«^ d r^ d dod PjSoggoooogggo o o o o o o o s ? 1 1 °5S°°°3S°gS3°Si oo o-^ ^oo o; ^ 3£5S8°°ia°°aS°8, ►^ dejdcjo d dd dj 1 ^sajissssssssssi f^o-oata<>90'0' » M d tfi d n S S S3gSS 2 O d rH oj d s °3 SS n d « i O rt o o o o O O rt "^ 2 ^ d H w d d d d d IS O r^ d N i >> 3 9 O °S|88g8q° o o o o d w .:S ■a . ■* H 13 O - II 1^ S3 333 r oo a ogo o d 1 o o A 1 ="ss as" a i|S8;^SS3 ^4 -4 .H n o (D n .0 RS!53SS:|8 9 SS»8S°3 i 88e8°a8 r^ d d fti d d i « « ^ O C^ A rH -H .H -^ d o w *• o o §8 S3SS O O O O rH O a. 38 a°°R .H o o d 1 j 3^ g°g5; j" i d_ d d d 3 8 a o o in ^ rH o O w n o (0 rH o odd n i' 2 • t^' 2 i* Q' N(r)*in«c^ (Ao. St • o SS da !s a** Is £3 '?' 00002^ SOOOOJDH o o o OOO'^O'-l oo HO '-^'^oooM ooosdnd H^MMHO n>-ldM^Oi-4 MO^CNO f-l^-#dddd t> oi ^ n n r^ ^«««rld«ii3 "^ 5 S8:1SSg dSSS^SSSS noM<~iMr4 ooH^dnd OMr-tNo NOtiHi-tOC lONOOiH OOnHOC 83g°8 ■3S°83!S O r-t ^ O H^ HOO *oc"«o aoNOpj«c o o o o o d o eq lO iQ to — ;f odd o 31 o 9 e^ o o • o d<-4 OQOOO aooonm-^ ^ d d J fi riiiiiTiTiiiti •#inoc^cDaio«^(Oi>Oi-1c^ gk9ooao>ooooor-i.-J>H cDa}mco J) nn ir> tc -^ 9 ^ n inoi ^ N (> C> C-' CD i Q ^ W tO^uOOC- (COO-' o 8? US 3" 11 i 1 1. .. O O^ O O O 1 1 eassssg « o o o d r^ d ^ ■c KSSSSS? N ^ W D O JO to to rH M 4 9 CI O to (Q N CO O <0 s W to D d d d -H i sssssss « .H to W * to r-1 s essssss "^ t^ n ^ f-t ^ --t n 1 SS°S3SS - to M to ^ O ■* s tfi O •-• M Q m in o " * « K r-t oi O O r^ « J 3 J =S°SS25 O ^ ^ rH N °SgS=5S O O 3 O O =°°ssss i 1 ■? to O O N C^ E^ « C-. O (O -H M t^ 5 O -^ N 3 O — 2 S i 2 ?i 8 3 si • •r -n ai tf o z" a a —• o a si tn 8SS sssas a 1 ^OOO ogooo d 1 °sa::i pases; ^ i t 53S3S§:^gS OW«D ftlO--IOO sssssasas Q ffi >. ^ NrH«dot-nc-« o SSSS="S3SE g* U1.J.03 rt-oevj, «• kt SS as 9 3SSSSS3S S SSSS°SSS3 ^■4* • ^8°3Sgsas O O 3 O O D O « N0300gO£» c o 1 ii IS 4 : 1 d d ^ d tfJWrtOt^OMOC- r> rt CD H * ■* *^ ^ _•. -M 3 ^ 3 O M ■ t0.fV>OC^(DO(3'-tN u n o O K 8:: d3 fj 33 82.48 16.18 13.47 20.63 aasaa 21.82 15.44 20.67 30.68 39.98 24.47 16.48 19.20 28.40 s 3 O O O O 3 o s o o o o d odd d 1 a3_ss rH CM*3 rH gggooo r-< d O aasaasasg •HOO^O^OOO asss s saass SSS83S3Sg3 ^ o o o o O -H O O ^ no-t-^onorHr-t 8S3!S to d d ^ ssass SSgS5S§S8 * H * M W MWHWjO^OtOC* J3 3S§S ■* 3 -^ d S8S8S -H ■* m o « OT|l*lOr^lOC^O(D 9 •-> 33SS •* n n ta SSSS8 A -i S3X83S83E9 <-ltOlOISAOMOW5 S 3 3 & S «^ d H c^ o rH d d SS8SSS°5ei •HOM^dd d<4 i SS85 rH d d d 33SS3 ci 6 '^ in A '«a)0^vop;9i0(p OrHCOO'HdO'^'^ o 3S8°SS3°S°S8SS o w - -id-; ,; o d -<■ -■ « CO 5 SS = 8 3 o d H d S = S ° 5 d H d 3 " S S ° ^ o ^ S°S38S?°S o a o a A o d °gS°gS°88 o ^ o a d d a 3 O N O O 3 "sssf 3 S S S 1 S ' ° § s •H d d 5832^ SS88S a a 9 9 9 OPJlOOOMMOM C- .* ■» .HO© ^ d O H J d J«wto*io«c^ (n^ a • 1 5SsSSSS833Sit2S83aSS£3S ■1 8t' ■• •■'' lio.. Sr°33dS8S8SSSS°'?§38S38 1? °* o««an»ooonc; Jnr^^cC^o 9 Si«eSSSSSg8S28SSSSSSSSS as "^ «> ■• o «■ « f' <3 «; «■ o rf « « N -4 o o r^ o N o <-; i o8s°qSSS°S§S3SSSSgS3°° "^^ ^An,; oodgrtcSn^onn i ^S8SssS°3Sg23SSSSE:8§°S J s ?2!!!°r^S52!2l!!5r^ « ' s. 5d°§S3§''°SSS§S°°°°°3° in n °d oddo dddod d^ 9 a 1" n" t ° ,- OOMOO O OO H 2 g - !l 5 sssss s='°s°sga°°°s°°s ~-*doJJo3 D oJJ ^* d y C. J a 2 C c -1 liliilliiillil le St *• u m o S5 !33 • 00 u g . • a h ss^s ! asaa l\ OOOOO i fisasa «««•*<». .. ^ ■9 38as° p4 ^ O (4 e t a S3SSS O •-« M OC- gssss « «) ^ NN a sssss 1 "•a-?. ..1 i 888°8 r> A O M i ss°xa| d r^ d cti 1 ** s d -4 r^ A S oogoo 1 o « 1 ■^SKS" d OO ■ 1 C- O OO o > O O 1 6 ■ « n « t- o 9 1 52=2221 3^ I s 2? •a as 2- 3- • - ■J so 88 li da o 1 a»8 d d t 1 2 9 8S3 « N •• d -4 RK^ S •H M n r> 838 * RS8 as 2 i 88° 8 -H -^ d w i *• J* M o aio o « .1 a 8 m m s o ao o O Q O O ^ » « £ ^ 2 t^ « A « c^ « 9 9 » »» » T. ^ 1 1 1. « t 1 - " " 1 5 1 I- ^ • 15 e o 33 I 'Sg38 I I d G4 o ^ 40 t- CD A , t^ »i Ea o B d M n >H o g I S J) UJ o S " i -J "^ d -• '^ r-< n n n : !°Ssi i ! I i :S8°2 ■• o o c^ till O ■* «•! O a a 9 Q s 1^ S5 SS?S5S8SgS§8SS Sm 1 •- as 238a3S3asig3S3a 1 rjoaoeioooQnoc<-ooooo« o O O -H o 1 SSa33a8SS''°5SJS°S;J 1 onooooono o o -H 3 «3 o- I s 9 8SSSS8S?S38S3SagSS ^NOnO'^-tO^MNnC^O'HOCM ;«s £ S SSS3SSSSSSSS3:1SgSa ? dcito-idndr^nNdcidindNno Si?" 8ud J3 sss^zjssggs^^^sssass fii? *00 rt«e*rH*rt r^^t^rHO-HKl C O i SS?g8SSXS83SSgS3SS ai t^^gj^^OOtOIOMDOO-^OrtOlO i 8 S 3 ° e 8 S S S S 5 2 3 S 3 ° ° no^ w,^.HftIrtrt*'H■*lDrt i gS°3SE!S!SaSg8gS2°S O r^ O M to d d t-t ^ r^ -< O rH iH W „ n en *« 5O3O«ggg09^«g^^O« H o o r^ rHO^MOOO^OrHO o OS a OOgO!>00>Q0200000t»Og 1 p - s OO OOOO OO • « £ = « oc-e-ot^oMaoooooooooc^ i - ^ I o A9o9>99(»99, Bi.4 '.. .. ..' - 82 « a ^ •-• Of — y a a n S *i a se o • , i S5SgS8SSSgSS338g5 a?!2»53:i83d22Sa:J23 ooooaoooooooovoooo d d d 1 oNOodd Md ooo MO 9 S S g S ° 8 S 8 S 2 8. S 8 S 2 8 S S woidw ^dd'4'-4-4f>d'40<^oc4 s S SS!2§g8SSSSg5S8SKE2 D.-ind^nd^c4rH-«Ndd daifoo i 3SSS8838Sa°8 8g32SS niooNoiAodnM r^^w♦*^^o« i!:3S8Sg;3SS8SS;g8SCe O«M«-H0^nirt«0JW3 SMtAM i 8Sa°S§SEJg8SS?SS°° i gS°8SS3S8gS8SSS"'2 O^ ONlOOO'^NO'-tOi^'^ « o 8"='S25SasS°XS°33°S d J d -4 Q -4 -4 d dn mo o C^000099>000000«0«00 n "^ "^ 'I ® . o o d ^ o o 1 X 8 OOrtC>^-«OCvoOOO^OOOOA ACkOtO^'^ « O t* a do o o o ol I "■ • : ooooo^or-noo OO ^o^S5J • J* 6 O -HO d J '^->| SS3f:2 383S8S8SaS38^a 232S5 2S8«3eS8SS8a^s! 99»ao ••»»»2****^*22*S is °l «* n a • o • ^ o 85 - T? v2nn3oocD dasaassa ooooooo* -^ « J -^ O -H t j np)OMoi.#o^ . o ^ O '^ M a •* o 1 -« ^ M n^ M ^ s»°assgs -> rH O ^ r^ O O iH :^ M O O -4 I oooooe»o«i I o o o o ■a ° ^ I •1 --too 1? <^ o 3 PD«C»SOn^«| I i I ( I till a. n o ^ 3 . a • o o 5 3 1.!. g ..^. 1 c^ o oo 1 ^I^SSS O oj o o « 1 3SS8 W O O lO J5 s 5335 ; £ S§3 1 ■* cs ^ s" 3S s g " i *» 'H r-4 ■% S"S° o ^ s 1 °8S° o o o o s a « O o r~ CO rj * « « f^ .. .. « .. „ s S3*E SS2£SS?g3 • s^ 3SS ass-^saads iS a ^ o o o g oo o o coo S) o 1 °S JSSS3 O C" o o O 0-4 o i £S§8S°2S 5§X ■ ^ n o « o o o N rt e^ J= 3S3S5gS8 S3S 4 ON^OOtOO,.^ O ^4 o e^ o - ^ ;ss gjss °ss If is as 3 •* rt o M (0 n o ^SS SSSg ■ft e- g 'H o '4 M o ■« SS8SS ^ o o d S 238 °8SS ssss ^ N « rt O O «t «? o -^O" 3MdoO'«0.4 OO ^ ggoo-jjojoooo gooo if 1 a o O O O o o «3J»JOOOOOOOOOO»-jO o o d o d d d K O I^O O «2 OOOOO fiO « OOMO .? O O O 3 O 8 • s£s"58aS8SSit6SS8Sa8 •2225ls5Ss55as?S22 THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO SI.OO ON THE SEVENTH DAY OVERDUE. V"! •- Ece^ N/f-0 mm ^^^^ JUN 301986 M & 6 ml Book Slip-25m-7.'53(A8998s4)458 111611. Calif. Division of water reaourcea. Bullflt.l n PHYSICAL SCIENCES LIBRARY Tc82ii G2 A2 TC824 Aa •?U5,48- 4-6 A LIBRARY UNIVERSITY OF CALIFORNIA DAVIS 111611 3 1175 00664 0075