PHYSICAL SCI. LIB TC C2 A2 liliiPiBiiliiiijiiilli fjf Jt/rlNf IN K > h t I i ]. A. «::0'. i lllllllllMIIMIiiiiailiiiillliiiiiililliiliiiiiliiililiiiiiiiiiiliiiiiiliiiiiiii^ niimiimHiiniiiiimiim iiiNiiimiiiiiimiiin.iM Hancock Ubrary of Blotogy and Oceanography Artist's Conception of Box Canyon Dam and Reservoir (Mt. Eddy in Background) I I. o ^^ Hancock LI State of California THE RESOURCES AGENCY OF CALIFORNIA Department of Water Resources PHYSICAL SCIENCES LIBRARY UC DAVIS BULLETIN No. 100 MT. SHASTA CITY-DUNSMUIR AREA INVESTIGATION Preliminary Edition LOti-v^: «^ARCH 1963 '^"^^ UNIVERSITY OF CALIFORNIA MAR Z 1984 GOVT. UOCS. ~ LiBRARf HUGO FISHER Adm/nisfrofor The Resources Agency of California EDMUND G. BROWN Governor State of California WILLIAM E. WARNE U\rec\ot Department of Water Resources KB177 C15B8 100 I'- Vi ^fary of Biology ' , -eanography TABLE OF CONTENTS Page LETTER OF TRANS^a7^TAL xiii ORGANIZATION, DEPARTMENT OF WATER RESOURCES xiv ORGANIZATION, CALIFORNIA WATER COMMISSION xv ACKNOWLEDGEMENT xvi CHAPTER I. INTRODUCTION 1 Authorization for Investigation 1 Objective and Scope of the Investigation 1 Recreation 3 r. Flood Control k ,^ Hydroelectric Pover Generation h ^ Water Conservation k j.^ Irrigation h Municipal and Industrial Uses 5 -- Possible Supply to State Water Facilities 6 Area of Investigation 6 Climate 7 Geology 9 Population 9 Present Develojsnent 12 Lumbering 12 Agriculture 13 Transportation 13 Recreation l4 Related Investigations and Reports l6 iii Page Organization of Report I7 CHAPTER II. WATER SUPPLY I9 Precipitation I9 S-urface Runoff I9 Stream Gaging Stations and Records 20 Impairments 20 Quantity of Runoff 20 Groiind Water 23 Water Quality 25 Water Rights 26 CHAPTER III. INVESTIGATION OF SEPARABLE PROJECT PURPOSES ... 29 Recreation 29 Campers 32 Camping Use Without Project 32 Camping Use With Project 32 Camping Facilities 33 Day-Users 36 Day-Use Without Project 36 Day-Use With Project 37 Day-Use Facilities 38 Sightseers 39 Demand for Sightseeing ^0 Facilities for Sightseers ^1 Summary of Recreation Use ^1 Recreation Benefits ^1 IV Page Recreation Costs 42 Economic J\istification kk Flood Control kk Areas of Historical Damage k6 Present Flood Protection Works k'J Benefits From Flood Control k'J Estimated Historical Damages k9 Estimated Futiir« Damage k^ Flood Control Benefits 51 Cost of Flood Control 51 Flood Control Reqtiirements 51 Cost of Flood Control Facilities ^k Economic Justification 5^ Hydroelectric Power 55 The Pover Market 55 Box Canyon Hydroelectric Power Potential 56 Cost of Power Facilities 57 Economic Justification 58 Irrigation 5^ Wagon Creek Valley 58 Water Requirements 59 Water Supply 60 Export to Shasta Valley 61 Water Requirements 61 Water Supply 62 Page Economic Justification 65 Benefits (£> Costs Gd Conclusions 66 Mujoicipal and Industrial Uses 69 Water Requirements 69 Potential. Service Areas 69 Present Water Use 70 Futui^ Water Requirements 71 Present Water Supply 71 Future Water Supply 73 MunicipsLl Water Supply From Proposed Box Canyon Reservoir ... 73 New Water Yield to Sacramento-San Joaqiiln Delta 7^ Quantity of New Yield 75 Benefits 7fe Effect on Recreation Operation 76 Economic Jiistification 78 CHAPTER IV. BOX CANYON PROJECT 8I Engineering and Geologic Studies 8I Comparison of Upper and Lower Damsltes 82 Geology of the Upper Damsite 85 Right Abutment 85 Channel Section 87 Left Abutment 88 vi Page Spillway 88 Concrete Arch Dam 88 Construction Materials 89 Perviovis Material 89 Concrete Aggregate 90 I]q>ervious Material 90 Box Canyon Project 91 Dam and Appxirtenant Structures 92 Embajikment 93 Spillvay 98 Outlet Works, Single-Purpose Project 98 Outlet Works, Multipurpose Project 99 Reservoir lAnd Acqviisition 99 Recreation Facilities 102 Sunanary of Project Costs IO3 Project Operation I06 Single-Purpose Project Operation IO6 Multipurpose Project Operation IO8 Project Accomplishments IO9 Primary Recreation Benefits HO Secondary and Intangible Recreation Benefits 110 Fishery Maintenance and Enhancement HI Reservoir Fishery HI Downstream Fishery 112 Water Conservation Benefits » . 1JL3 vli Page Sigineering Feasibility and Economic Justification llU Single-Purpose Project III4. Multipurpose Project 11$ Cost Allocation 115 Project Selection ..... II6 State Park System Development 117 State Park System Lands II8 Need a nd Inrplementatieai 119 Advance Planning Program 120 CHAPTHl V. CONCLUSIONS AND RECOMMENDATIONS 123 Conclusions 123 Recommendations 129 TABLES Table No. Page Water Supply 1 Stream Gaging Stations Used in Estimating Water Supply 21 2 Historical Development of Impairments Upstream from Box Canyon Damsite 21 3 Estimated Future Impaired Runoff of Sacramento River at Box Canyon Damsite (1970 Impairments) 2U h Estimated Impaired Monthly Runoff of Sacramento River at Box Canyon Damsite for Selected Years (1970 Impairments) 2U $ Mineral Analysis of Sacramento River Water above the Confluence of Wagon Creek (Average of Four Seunples) 26 vxix Table No. Page Recreation 6 Estimated Recreation Use of the Prcjposed Box Canyon Project ^3 7 Recreation Benefits from Box Canyon JReservoir ^4-3 8 Staging of Box Canyon Recreation Facilities 45 9 Costs of Box Canyon Recreation Facilities 45 Flood Control 10 Estimated Historical Sacramento River Flood Damage to Dunsmuir-Castella Area 50 11 Estimated Sacramento River Flood Damage to Dunsmuir- Castella Area at Selected Annual Peak Flows 50 12 Estimated Annual. Flood Peaks for Sacramento River above Delta Gaging Station 52 13 Flood Control Accomplishment of 15,000 Acre-foot Flood Control Reservation at Box Cemyon Reservoir ... 52 Irrigation Ik Water Supply Available for Tributary Diversion Plan ... 67 15 Irrigation Benefit in Shasta VskLley with Diversion of 30,000 Acre-feet per Year from Sacramento River Basin 67 Municipal and Industrial Uses 16 Estimated Present and Future Municipal and Industrial Vfater Use in Mt. Shasta City and Dunsmuir 72 Box Canyon Project 17 Properties of Impervious Materials 91 18 Features of Box Canyon Dam and Reservoir 9^ 19 Single-Purpose Project, Estimated Cost of Box Canyon Dam and Reservoir 95-9^ Ix Table No. Page 20 Multipurpose Project, Estimated Cost of Box Canyon Dam auid Reservoir 97 21 Summary of Single-Purpose Box Canyon Project Costs .... 104 22 Summary of Multipurpose Box Canyon Project Costs 105 PIATES (Plates bound at end of bvilletln) Plate No. 1 Project Area 2 Lines of Eqxial Mean Annual Precipitation 3 Box Canyon Reservoir Recreation Land Use Plan k Box Canyon Damsite Areal Geology 5 Geologic Sections and Auger Hole Logs 6 Location of Construction Materials 7 Box Canyon Dam General Plan and Sections FIGURES Figiire No. Page 1 Temperature and Precipitation Variations at Mt. Shasta City 8 2 Estimated Recreation Use at Box Canyon Reservoir Site 35 3 Staging of Caaip Unit Installation at Box Canyon Reservoir 35 k Staging of Picnic Unit Installation at Box Cemyon Reservoir kO 5 Shasta Valley Irrigation Water Delivery Plans 6k 6 Fluctxiation of Box Canyon Reservoir Water Surface .... IO7 rUUSTRATIONS Illustration No. Page Frontispiece Artist's Conception of Box Canyon Dam and Reservoir 1 Dunsmtiir 10 2 Mt. Shasta City 11 3 Beach Sites at Lake Britton and Box Canyon 34 k Levee at DunsHuir Sevage Treatment Plant, 196O ... k& 5 Irrigated Pastvire in Wagon Creek Valley 59 6 Box Canyon Damsites 83 7 Upper Damsite 86 xL iVULIAM E. WARNE Director of Water Resources i. ABBOn GOLDBERG ihief Deputy Director REGINALD C. PRICE lepuly Director Policy NEELY GARDNER Deputy Director Administration ALFRED R. GOLZE Chief Engineer EDMUND G. BROWN GOVERNOR OF CALIFORNIA HUGO FISHER ADMINISTRATOR RESOURCES AGENCY ADDRESS REPLY TO P. O. Box 388 Sacramanto 2, Calif. THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES 1120 N STREET, SACRAMENTO Janxiary 21, I963 Honorable Edmund G. Brovm, Governor, and Members of the Legislature of the State of California Gentlemen : I have the honor to transmit herewith the preliminary edition of Bulletin No. 100, "Mt. Shasta City-Dunsmuir Area Investigation." The objective of the investigation was to determine the engineering feasibility and economic Justification of a water resources development pro- gram, which would include a dam and reservoir at the Box Canyon site on the Sacramento River about two miles southwest of Mt. Shasta City. As a result of the investigation, it was concluded that a dam and reservoir project at the Box Canyon site does possess engineering feasibility, although additional investigation of the damsite foundation is needed for final designs. Either a single-purpose recreation reservoir project or a multipurpose recreation ajid water conservation reservoir project at Box Canyon would be economically justified. Recreation would be the primary purpose of a multipurpose reservoir. Water conservation would provide a small increment of yield to the State Water Project at the Delta. The single- purpose recreation project was selected as the most desirable project. The Department of Parks gmd Recreation has recommended creation of a state park unit at Box Cginyon etnd favors development of a 4,800-acre State Recreation Area at this site in conjunction with the Box Canyon Reservoir Recreation Project. Department of Water Resources' Bulletin No. 100 recommends that the Legislature authorize the Box Canyon Dam and Reservoir Project as a unit of the State Park System and appropriate funds to provide for advance engineering planning studies. Sincerely yours. /f,JU^ f.^^ Director Enc. STATE OF CAJLEFORNHA THE RESCXJRCES AGENCY OF CALIFORNIA. DEPARTMENT OF WATER RESOURCES EEMUND G. BROWN, Governor HUGO FISHER, Administrator, The Resoxirces Agency of California wnUAM E. WARME, Director, Department of Water Resources ALFRED R. GOLZE, Chief Engineer JOHN R, TEERINK, Assistant Chief Engineer NORTHERN BRAUCH John M. Haley Branch Chief John W. Keysor Chief, Planning Section The investigation leading to the report was conducted under the direction of Stuart T. Pyle Senior Engineer William B. Shaw Senior Engineer by William D. Hammond Associate Engineer Carroll H. Hamon Assistant Engineer Special assistance was contributed by Arvey A. Swanson Assistant Engineering Geologist Stanley J. Thanpson Recreation Planner III Robert Hagy Recreation Pleinner II Donald K. Cole Associate Economist acLV CALIFORNIA WATER CCMMISSION RALPH M. BRODY, Chairman, Fresno WILLIAM H, JtMJINGS, Vice Chairman, La Mesa JOHN W. BRYANT, Riverside JOHN P. BUNKER, Gustine IRA J. CHRISMAN, Visalia GEORGE FLEHARTY, Fresno JOHN J. KING, Petal uma NORRIS POULSON, Los Angeles MARION R. WALKER, Ventura WILLIAM M. CARAH Executive Secretary GEORGE B. GLEASON Principal Engineer XV ACKNOWLEDGEMENT Valuable assistance and data were contributed by many agencies and private individuals during the course of this investigation. This cooperation is gratefully acknowledged. Special mention is made of the cooperation of the following: United States Forest Service United States Weather Bureau, Mt. Shasta City California Division of Beaches and Parks California Division of Highways, District II Shasta County Bridge Department Siskiyou Coimty Road Department Diinsmuir Public Works Department Mt. Shasta City Public Works Department Dunsmuir Water Corporation Fish and wildlife studies were conducted in cooperation with the following: California Department of Fish and Game Walter T. Shannon o..... Director Jack C. Fraser .......... Chief, Water Projects Branch George McCammon ..<>.. Fisheries Biologist IV John Hayes .. Fisheries Biologist II XVI CHAPTER I. INTRODUCTION Development of the water resources of the State of Ccilifoimia for their best possible use is vital to the continued economic grovrth of the State, This investigation was initiated in response to the interest displayed by residents of the Mt. Shasta City-Dunsmuir area in the develop- ment of their local water resources. Local residents foresee development of the local water resources as another step toward development of a year-round vacation Isind. Authorization for Investigation The investigation was suggested in 1958 by Senator Randolph Collier, Assemblywoman Pauline L. Davis, the Supervisors of Siskiyou County, and residents in the area of Mt. Shasta City and Dunsmuir. The Department of Water Resources conducted a short survey of the potentialities of a reservoir at Box Canyon and in January 1959, published a report entitled "Report on the Desirability of Investigating the Box Canyon Dam and Resei^oir Project in Siskiyou Coiinty." This report concluded that the investigation was warranted, that it would take two years to complete, and that its cost would be approxi- mately $115,000. In the Budget Acts of I960 and I96I, the California Legislature authorized the investigation and provided funds of $53,140 and ^30,750 to carry on the work during the I96O-6I and I96I-62 fiscal years, respectively. Objective and Scope of the Investigation The objective of this investigation was to determine the engineering feasibility and economic justification of a water resources development -1- program which would include a multipurpose dam and reservoir at the Box Canyon site on the Sacramento fliver about 2 miles southwest of Mt. Shasta City. The project area is located in Southern Siskiyou County euid includes the Sacramento River Basin above the town of Castella. Plate I, "Project Area," depicts this area. Reconnaissance indicated that a multipiorpose dam axid reservoir at the Box Canyon site might provide for recreation development, flood control and hydroelectric power generation, might conserve water for agri- cultural, municipal, and industrial use in the vicinity of the project or in Shasta Valley, and might develop a supplemental water supply to augment downstream water storage. The actual investigation to determine whether any or a-H of these purposes would be jiistified required: (l) studies of water supply, (2) studies of damsite conditions, (3) economic analyses of project purposes, and (k) formulation of a specific project. The scope of such studies, both in the field and in the office, is discussed in the following paragraphs. (1) Water supply studies to estimate the amount of water available at the Box Canyon damsite included compilation of available precipitation and streamflow records. Temporary stream gages were installed at six locations to provide records of tributary streamflow and to determine minimvmi summer flows. The completed estimates of water supply were used to determine the size of reservoir needed for the possible uses and benefits for each purpose. Flood hydrology was investigated to determine the spillway requirements for a dam at the Box Canyon site. (2) Topographic maps of the dam and reservoir site were made by photograrametric methods as a first step in engineering design. During a geologic survey of the damsite, maps were made to depict the surface and -2- subsurface formations, and limited auger drilling was imdertaken in questionable areas of the damsite. More extensive geologic exploration would be needed before a construction design could be prepared. An investigation was made of locally available construction materials for earthfill, rockfill, and concrete structures. (3) Design and cost estimates were prepared for several types of dams, including appxu-tenant features for the various purposes included. These estimates provided a basis for selection of the best location for a dam, economic analysis of the multipurpose features to be included, and formulation of the recommended project. (U) Engineering and economic studies required to analyze each of the possible purposes prior to formulation of a specific project are discussed in the following sections. Recreation Considerable attention was focused on recreation studies to determine present and future recreation needs and uses within the project area. Field investigation included studies of the use of the project area and similar recreation areas by campers and fishermen. Field studies also contributed information which was used in choosing a reservoir size and in delineating recreation areas. A contract was made with the Department of Fish and Game to evaluate the effects of a reservoir at this site on the present sti^am fishery. Office studies included determination of recreation benefits, development of a recreation land use plan, recommendations of optimum size and operation of a recreation reservoir, and estimates of costs for the required recreation facilities. The benefits of recreation development proved to exceed the cost of such development. -3- Flood Control Dajnage sustained during recent floods in the vicinity of Dunsmuir and Castella was estimated from data collected from local interests and from field interviews with persons who have suffered loss by flood waters. The frequency of damaging floods was estimated and the monetary value of average anniial flood damages was calculated. The cost of added facilities required at the damsite for full flood protection was estimated. The cost of providing flood control proved to be greater than the benefits such control would create. Hydroelectric Power Generation The amoiint of power which could be generated at Box Canyon Dam under several operating conditions of various reservoir sizes was estimated. A market analysis of the salability and value of power in this area was completed. Costs of installing power features and producing power to be sold at marketable rates were foiuid to be greater than the estimated benefits. Investigation of power production as a purpose of Box Canyon Dam and Reservoir was discontinued at this point. Water Conservation A dam and reservoir at Box Canyon coiold conserve water for irriga- tion, municipal, and industrial use both in the project area and in areas supplied by the transfer of water through the State Water Facilities. The following discussion will treat irrigation and municipal and indtistrial uses separately as they pertain to the project area and jointly as they pertain to supplies transferred through the State Water Facilities. Irrigation . Two potential water service areas were investigated, (1) local lands along Wagon Creek, and (2) lands of Shasta Valley, near Edgewood, at the uppermost end of the Shasta River Basin, -4- From a field survey, the amount of irrigable land presently developed in the Wagon Creek area was determined. Data from prior Department of Water Resources studies were used to estimate the total amount of irrigable land in this area and possible future water needs. Field studies, including interviews with local water users, were conducted to determine present water supply. When studies showed that there would be no demand in this area for irrigation water from Box Canyon Reservoir, this phase of the investi- gation was terminated. The possibility of exporting water to Shasta Valley for irrigation also was studied. Information collected during prior studies by the Department of Water Resources was used to determine the need of and ability to pay for irrigation water in Shasta Valley. The cost of developing and trans- porting water from the Upper Sacramento River Basin was found to exceed the expected ability of irrigation water users in Shasta Valley to meet water costs. Municipal and Industrial Uses . Well drillers, local residents, and representatives of agencies wliich presently supply water to municipalities and industries in the Mt. Shasta City-Dunsmioir area were interviewed with respect to present and expected future municipal and indxistrial water supplies. Numerous undeveloped springs near present municipal supplies were inspected during the course of a limited ground water basin study. Estimates of growth in population and in per capita use of water in the project area were made to aid in determining future needs. When studies showed that the foreseeable municipal or industrial danand for water could be met from the development of local springs or wells, no further -5- consideration was given to the inclusion of urban water supply features in the Box Canyon Project. Possible Supply to State Water Facilities . When the water supply is low at Shasta Reservoir^ , releases of water from Box Canyon Reservoir coxild be transported by the Sacramento River to the Delta where the water eventually would be distributed through proposed state facilities to areas of need. Studies were made to determirie the amount of water that would be available from Box Canyon Reservoir for such distribution and the benefits creditable to providing new water at the Delta. These benefits were compared to the costs required to add this purpose to the project and the reduction in recreation benefits. The net benefits would equal the costs of including this water conservation purpose. Area of Investigation The Mt. Shasta City-Dunsmuir area is located about 60 miles north of Redding at the headwaters of the Sacramento River. It lies along the bottom of a canyon formed by the Trinity Mountains on the west and Mt. Shasta on the northeast. Although the bordering mountains rise to 9,025 feet at Mt. Eddy and to a spectacular lU,l6l feet at Mt. Shasta, the area itself is not at high elevation. The summit of the topographic saddle between Mt. Shasta City and Weed is less than U,000 feet, and the area funnels into a narrow river canyon at Dunsmuir, where the elevation is about 2,300 feet. The Box Canyon Reservoir site lies about 2 miles southwest of Mt. Shasta City, just below the junction of the Sacramento River and Wagon Creek. The Sacramento River heads at Gumboot Lake and flows east to this junction. Wagon Creek heads further north on the slopes of Mt. Eddy and flows east just south of the saddle between the Sacramento River drainage 1/ This condition was assumed to occur for about seven consecutive years of the 50-year repayment period of the project. -6- and the Shasta River drainage basin. It turns south and, as it flows through Wagon Creek Valley to the junction point, picks up the flow of many springs from the slope of Mt. Shasta. The area is primarily one of pine and fir forests with stands of hardwood forest at the lower elevations. The forest cover, as well as scenic mountains, contributes to the attractiveness of the Mt. Shasta City-Dimsmuir area as a recreation spot. Climate The mild summer climate in the vicinity of Mt. Shasta is a definite advantage to the recreation potential of this area. Summer temperatures reach an average high of 85 degrees Fahrenheit at Mt. Shasta City, and usually rise above 90 degrees only 18 days a year. Night time temperatures are cool. The winter climate is somewhat more severe. Temperatures drop below freezing an average of 137 days a year with an average low temperature of 2U degrees during the winter months. Although the summer months are dry, heavy precipitation occurs over the basin during the months from October to June. The average precipi- tation for the entire drainage basin above Dunsrauir is about 50 inches a year. Average precipitation ranges from about 34 inches at Mt, Shasta City to more than 60 inches at higher elevations. Much of this precipitation occurs as snow which, at higher elevations, remains on the ground until summer. Average annual snowfall at Mt. Shasta City is 102 inches; however-, the depth of snow on the ground rarely exceeds two feet. Figure 1 indicates climatic conditions in the project area. -7- FIGURE 1 1 1 HIGHEST MAXIMUM t \, TEMPERATURE \/ / \ \ / r _95_ \ / / \ \ s. / / / \, \ \ V .50 / / // \; \^ V \ / / / / // V A \ / / / y / 5 \ \^ A / / / / V \^ \\ \ \ / / / / / / \ \ \\ \ / / / / / / \ v v\ \ / / / / / \ V A / / / / / \. \ A \ / / / / / \ \ \ / / 1 \ / / A ^ LOW EST 1 aAXIMl. M \ \ ■7^- / \ / \ / \ / \ )ISTR IBUT TEMF ON ERAT F MA URES XIMUM HIGH TE -ST M riPERA INIMUM TURE v^^ / \ / \ / / \ / 95 \ \ /' / / 76 X \ \ y / / / s> \ s. \ / / V A^ N^ \ \ / '/ / / \: \> ^. \ ^ '/ / / 1 v \ s s\ \ ^ / / \ \ \\ \ ^ y / 1 \ ^ \ N / / / \ \^ / / / \ \ / / -Si I V, LOWEST TFMPFF MINIM ATun U_M \ I / \ y \ \ DISTRIBUTION OF MINIMUM , TEMPERATURES JAN FEB MAR APR MAY JUN JUL. AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC o ) ^ ■^' \ 4 ^ ^ ^^^ 2 00 ^ s^X, ^^ ""1 avERAGE YEARLY PRECI PI TaTION = 34 4 INCHES 84SE0 ON 53 5 YEARS OF RECORD FROM 1906-1959 DAILY PRECIPITATION TOTALS 1 [ 1 1 1 1 1 1 1 1 1 JUL AUG SEP OCT NOV. DEC. JAN. FEB. MAR APR. MAY JUN TEMPERATURE AND PRECIPITATION VARIATIONS AT MT. SHASTA CITY Geology A study of areal geology provided ijiformation needed for analysis of the water supply and to appraise the suitability of the Box Canyon Dam and Reservoir site. Volcanic activity has played the major role in the geologic development of this area. Box Canyon damsite is located near the geologic boundary between the Klamath Mountains ana the Cascade Range. Characteristic rock formations of both mountain ranges are present nearby. The Klamath Mountains, lying west of the reservoir area, contain intrusive, sedimentary and volcanic rocks. The Cascade Range contains volcanic rocks which are divided into two units: The Western Cascade series and the High Cascade series. The Western Cascade series, an older outcropping, lies to the west of the peaks of the Cascade Range and extends north from Mt. Shasta into Oregon. The High Cascade series, a younger imit, includes both Mt. Shasta and Mt. Lassen. The erosion which preceded Western Cascade volcanism created a valley between Rainbow Ridge and Ney Springs Creek. The lava flows that contributed to the Western Cascade series covered any sediments that may have been deposited in this valley. These lava flows outcrop in several places to the west of Box Canyon and in the reservoir area. They form the walls of Box Canyon and apparently terminate a short distance east of the canyon. A lava flow which ages ago blocked the canyon at Mott, several miles below the damsite, formed a lake that extended around the west end of Box Canyon and into the proposed reseirvoir area. From the proposed reservoir area to Mott, the Sacramento River has exposed the sediments which indicate the past presence of this lake. Population Two towns, Mt. Shasta City and Dunsmuir, lie within the area investigated. Illustrations 1 and 2 present aerial views of these towns. -9- Dunsmuir (Mt. Shasta in Backgrotmd) -10- Mt. Shasta City (Black Butte in Background) -11- According to the I960 census, Mt. Shasta City has a population of 1,963 and Dunsmuir, one of 2,873. Two other towns located quite close to the project area are McCloud, population 2,140, which lies approximately 10 miles east of Mt. Shasta City; cind Weed, population 3^223, which lies 8 miles north of Mt, Shasta City. In contrast to the expanding population of many other California cities, the population of each of these four tovms has remained nearly constant during the past 20 years. The i960 population of the entire project area is about 7,500. It is estimated that the population will grow to about 27,000 within the next SO years. Present Development The Mt. Shasta City-Dunsmuir area lies in a forested area north of the Sacramento Valley. Through this area passes the most favorable transpor- tation route from the Central Valley in California to communities in Oregon and the Northwest. Residents of the Mt. Shasta City-Dunsmuir area have tradi- tionally depended upon lumber, the railroad, and, to a lesser extent, upon agriculture for their livelihood. Although the lumber and rcdlroad industries have experienced a decline in recent years, the income provided by agriculture has remained relatively stable. An additional source of income has resulted from the rapidly expanding use of the area for recreational pursuits. Lumbering . Prior to settlement of the Mt. Shasta City-4)unsmuir area by the white man, the southern slope of Mt. Shasta and the surrounding territory were covered by virgin growths of pine and fir. Subsequent decades of lumbering and destructive forest fires have reduced the amount of harvest- able timber available and left many areas unproductive. Logging, milling, and transportation of lumber supported the early economy of the area, but the modem practice of hauling logs great distances -12- by truck and rail has resulted in a reduction of local milling and manufacturing. The dwindling of virgin timber resources and the slow recovery brought by reforestation practices may result in further decline of the local lumber industry. However, the demand for forest products has remained high during recent years and the lumber industry continues to provide a major source of income for the area. Agriculture . The extent of irrigated and irrigable lands within the Mt. Shasta City-Dunsrauir area is very limited. Agriculture mainly consists of the raising of cattle and those pasture and hay crops required to support cattle. Crops, for profitable production, generally require irrigation from May through October. Most of the acreage suitable for tillage or irrigated pasture is presently developed and provided with irrigation water from the nearby creeks and springs. Transportation . The location of the Mt. Shasta City-D\ansmuir area on an important interstate transportation route contributes in many ways to the economy of the area. During the early gold rush days, the main route of travel from the Central Valley to Oregon passed from Redding farther west through the gold-producing areas of Trinity Center and Callahan to Yreka. The route from Redding to Mt. Shasta City was more difficult to open up. Tales are told of the hardships endured by ranchers who drove herds of cattle up the Sacramento River Canyon to reach Shasta Valley. VJhen the railroad was constructed from Redding to Dunsmuir in 1886 and on to Oregon the next year, the first impetus was given to the lumber industry in the Mt. Shasta area. In addition to its importance to the lumber industry, the Southern Pacific Railroad, with switchyards and track maintenance shops located in Dunsmuir, contributes significantly to the economic life of the project area. Prior to the exclusive use of diesel locomotives on this line, large repair and overhaul shops for steam locomotives were located in Dunsmuir. Because -13- service for diesel equipment is now provided elsewhere, the railroad reduced its repair shops in Dunsmuir to the minimum. Following this reduction, in the early 1950' s, the area felt the impact of the payroll loss. In the ensuing years, economic stability has been achieved and continued employment at the present level is expected. Highway access has been improved over the years until now, in 1962, most of U. S. Highway 99 between Redding and Mt. Shasta City is built to four-lane standards. This highway branches at Weed with U. S. 99 continuing into Oregon by way of Medford and U. S. 97 by way of Klamath Falls. A connection from Mt. Shasta City to areas farther east in California is provided by State Route 89, which intersects U. S. 299 near Bumey. The north-south highways are heavily used by both automobile travelers and by commercial trucks. The entire system is heavily used by vacationers during the spring, summer, and fall months. Recreation . The Mt. Shasta City-Dun smuir area, as well as many other comraionities in Northern California, is growing in its attraction to recreationists. The reasons for this growth stem both from the natural attributes of the locality and from the population surge in other portions of the State. The attractiveness of the forests and moimtains, coupled with the pleasant climate, provides the setting that recreationists seek. It is true that there are many other such spots in this State, but as the developed areas become crowded, recreationists tend to go to less crowded areas. Modern highways and autos are bringing more and more visitors to the sparsely populated northern areas. Mt. Shasta itself is an outstanding attraction. The 14,161-foot peak of Mt. Shasta dominates the entire project area. For much of the year snow covers that portion of the peak above 8,000 feet and several glaciers cling year around to the mountain. -14- Around the skirts of the mountain, and in the He Cloud River and Mt. Eddy areas, fish and game abound. The upper reaches of ihe Sacramento River above Shasta Lake, for instance, are noted for the excellence of their trout fishery. Much of this part of the river lies within the project area. Many small mountain lakes, at elevations of from 5,500 to 7,000 feet, are located in the Eddy Mountains at the headwaters of the Sacramento River. Rainbov7, eastern brook, and brown trout inhabit the lakes and streams. To augment the heavily fished areas, the Department of Fish and Game plants many trout from its hatchery at Mt. Shasta City. Each hunting season, hunters fill many bag limits with native deer, bear, squirrel, and quail. Despite easy access to tne project area, however, little has been done until recent years tov;ard the organized development of recreational opportimities in the area, although such opportunities long have been recognized as among the best in Northern California. In 1958, the completion of the Mt. Shasta Ski Bowl chair lift and lodge initiated a large-scale attempt to popiolarize the area for winter sports. Heavy snovrpacks that reached 200 inches on the slopes of Mt. Shasta long had suggested this possibility. The ski season normally would be long, beginning in late November and continviing through June, Unusually light snowfall plagued the operation of the facilities during the first two seasons, although normal snow conditions prevailed during the I96O-6I season. Nevertneless, during the first year of operation of the ski bov;l, retail sales in Mt. Shasta City were reported to have increased considerably. Plans for future development include toboggan, sledding, and cross country ski runs. Private individuals and organizations recently have also developed improved camp grounds along the Sacramento River near Mt. Shasta and at Castle Lake. Such facilities are used during the summer vacation seasons. -15- Seeking a means to spur their economy further, many residents advocate a reservoir at Box Canyon. Such a reservoir would draw to the area many of the water sports enthusiasts who abound in increasing numbers in California. It would provide additional attractions to fishermen and campers and contribute toward a well-rounded, year-round recreational development which could supplement an economy whose only other major support comes from lumbering, the railroad, and agriculture. Related Investigations and Reports The Mt, Shasta City-Dunsmuir Area Investigation included review of several reports of prior investigations by the Department of Water Resources and other agencies. Of major importance are the following: California Public Outdoor Recreation Plan Committee. "California Public Outdoor Recreation Plan." I960. Department of Water Resources. "Water Resources of California." Bulletin No. 1. 19$1. "Water Utilization and Requirements of California." Bulletin No. 2. 195U. "The California Water Plan." Bulletin No. 3. 1957. "Northeastern Counties Investigation." Bulletin No. 58. I960. "Klamath River Basin Investigation." Bulletin No. 83. I960. "Shasta Valley Investigation." Bulletin No. 87. 1961. Department of Parks and Recreation. "Mt. Shasta-Siskiyou Area Study, An Analysis of State Park Potentials in Western Siskiyou County." January 1962. Additional studies relating to water resources and water i*equire- ments conducted by such federal agencies as the Bureau of Reclamation, Geological Survey, Soil Conservation Service, and Corps of Engineers were used to the maximum extent possible. -c . -16- Organization of Report The following four chapters of this report cover water supply, investigation of a multipurpose project, formulation of a reservoir project, and conclusions and recommendations resulting from the study. In Chapter II, the water supply available for project use is estimated, taking into consideration impairments to the supply, water rights, and water quality. The investigation of each separable purpose is discussed in Chapter III, and the justification for including a purpose in the final project is analyzed. The final project formulated to fulfill the requirements of the economic purposes is described in Chapter IV. Costs and benefits are evaluated, and the engineeiang feasibility and economic justification are discussed. Chapter V presents conclusions and recommendations which were reached during the investigation. -17- CHAPTER II. WA.TER SUPPLT The Mt. Shasta Clty-Dunsmuir area is one of heavy precipitation and abundant water supply. The Sacramento River at the Box Canyon damsite con- sistently produces a greater runoff from a drainage area of 122 square miles than does the Shasta River, under natural conditions, from a drainage area of 800 square miles at the point where it discharges into the Klamath River. Precipitation In the watershed above Box Cajiyon damsite, the precipitation varies from over 60 inches at high elevations on Mt. Shasta to the east and on Mt. Eddy to the west to less than kO inches at lower elevations near Mt. Shasta City. On the average about 70 percent of the ajmual rainfall occurs between December 1 and April 1. Plate 2, "Lines of Eqvial Mean AnnufiO. Precipitation," shows the precipitation pattern on the Sacramento River watershed above Shasta Reservoir. Surface Runoff Fall and winter rains on the relatively impeirvious basin area west of Rainbow Ridge provide one increment of runoff \diile another increment Is provided by the sustained springtime imnoff from melting snows in the high mountainous areas. Precipitation on the Mt. Shasta side of the basin does not produce surface runoff directly into the Wagon Creek system, but Infiltrates into the extremely porous volcanics to increase ground water storage, and eventually discharges as part of the sustained simmer yield. This sustained s\jiTimer flow is regulated both by storage in the Mt. Shasta snowpack and by groxmd water basin seepage into the Wagon Creek drainage system. The natoiral flow of the Sacramento River at Box Canyon damsite during the summer and fall seldom drops below kO second- feet. -19- stream Gaging Stations and Records Records of discharge of the Sacramento River above Shasta Reservoir are available at four stations. The record of the Trinity River at Levlston vas used to estimate missing years in the Sacramento River records. The stations are listed in Table 1 and locations shown on Plate 2. Impairments Nesirly all exports and diversions of vater from the Sacramento River above Shasta Reservoir occur upstream from Box Canyon damsite. Therefore, all four stream gaging stations on the Sacramento River listed in Table 1 have historical recorded discharges which are less than full natural flow by the amount of impairment \rpstream from the damsite. The total impairment is com- jxjsed of three types of use: Consumptive use of water on 2,700 acres of irrigated pasture along Wagon Creek o Export of water from North Fork Sacramento River to Shasta Valley for irrigation o Domestic use of water in Mb. Shasta City and outlying rural areas As seen in Table 2, i960 total impairment was estimated to be 7,900 acre-feet per year. This impairment was assimied to have increased proportion- ally from in I89O to 7,900 acre -feet per year in 1955 and to have remained constant through i960. For the purposes of establishing water supply estimates for project operation studies, upstream use was assimied to be fully developed to 13,200 acre -feet per year by 1970. Quantity of Runoff v . The surface runoff available for storage at Box Canyon Reservoir after I970 would be the impaired discharge of the Sacramento River at the -20- TABLE 1 STKEMl GAGING STATIONS USED IN ESTIMATING VfATER SUPPLY Station : Drainage area Operator ; in square miles Period of record Sacramento Pliver Near Mt. Shasta DWR* 129 At Castella USGS** 257 At Delta USGS U27 At Antler USGS )+6l Trinity River At Lewis ton USGS 727 May 1959 to date Oct. 1910 - Sept. 1917 Oct. 1919 - Sept. 1923 Oct. 19Ml- to date Oct. 1910 - Dec. 1911 May 1919 - Sept. 19^^! Oct. 1908 to date * Department of Water Resources ** United States Geological Survey TABLE 2 HISTORICAL DEVELOPMENT OF BtPAIRMENTS UPSTREAM FROM BOX CANYON DAJ^ITE (In acre-feet) Years : Wagon Creek : diversions : Export to : Shasta Valley : Domestic : Use : Total 1885-1890 1891-1895 700 1896-1900 — 1,700 1901-1905 ___ 2,700 1906-1910 ___ 3,600 1911-1915 l+,500 1916-1920 5,200 1921-1925 6,100 1926-1930 __- 7,000 1931-1960 5,500 1,600 800 7,900 1961-1970 9,200 1,600 2,14-00 13,200 -21- damsite after that date. In the preceding discussion it vas assumed that at that date the impairments to this discharge would probably reach the maximum. Estimates of future impaired runoff at the site for use in project operation studies, therefore, were made by subtracting the 1970 level of impairments at the site from estimates of natural runoff at the site for the 50-year period 191O-II throvigh 1959-6O. Natiiral runoff at the site during this period is assumed to be representative of that which would occur dviring a 50-year period following I97O. Altho\igh no historical record exists for natural runoff at the damsite, such runoff is assumed to be Sk.6 percent of the natural runoff occurring at the Mt. Shasta stream gaging station because the drainage area above the site is Sk.6 percent of that above the gaging station. Located one and one-half miles downstream from the damsite, the stream gaging station on the Sacramento River near Mt. Shasta provides a continuous record of runoff from May 1959 to October 1960. The natural rvmoff at the site of the gaging station occvirring during the remaining years of the 50-year period (I9IO-II through 1959-60) was estimated from the records of the stream gaging station at Castella in proportion to the total volume of precipitation above each station. Because the records at the Castella gaging station themselves did not cover the entire 50-year period, they were extended, primarily by corre- lation with records at other points on the Sacramento River as well as with the record of the stream gaging station on the Trinity River at Lewiston. All estimates of annual runoff were made on the basis of natural runoff by adding estimated impairments to the recorded flows. Estimates of annual impaired runoff which wovild have occurred at Box Canyon damsite over the last 50 years if upstream impairments had been at the 1970 level are presented in Table 3. It was assxomed that this 50-year -22- period may be taken statistically to represent any 50-year period following 1970. The table shows that estimated future average annual impaired rxinoff during such a 50-year period would be 192,000 acre-feet, with a high of 368,000 acre-feet in the fifth year (191^4-15) of the period and a low of kO,600 acre-feet in the 14 th year (1923-24) of the period. Although variations in annual runoff are the basis for water supply estimates, monthly distribution of the year's supply also plays an inrporteuat role in the ability of a small reservoir to regulate streamflow. For the summers of 1959 and i960, good records of monthly runoff are available. Monthly runoff estimates were made for the two low flow years of 1923-24 and 1930-31 • An estimate was then made of the percentage of years these dry summers would recur. As seen in Table 4, the minlimim summer flows expected with 1970 impairments are 500 acre-feet per month or about 8 second-feet, and these minimums would be expected about 4 or 5 percent of the years. Ground Water The slopes of Mt. Shasta are covered by deposits of porous volcajiic ash and debris blown out during past eruptions or carried downhill by subse- quent erosion. Rain falling on the mountain slopes infiltrates immediately; very little runs off in surface streams. Snowfalls are retained on the mountain both as winter snowpack and as permanent glaciers. Melt water runs in torrents down the mountainside for short distances until it, too, infil- trates into the porous soil. Reference to the USGS Weed Quadrangle discloses the near absence of surface drainage from the west and southwest slopes of Mt. Shasta into the Sacramento River. The triangle approximately defined by Dunsmuir, Black Butte, and the peeik of Mt. Shasta, about 40 square miles in area, is an area of gro\ind water storage. The numero\is springs >rtiich emerge from the hillside on the east side of Wagon Creek and the Sacramento River -23- Year TABLE 3 ESTIMATED FUTURE* IMPAIRED RUNOFF OF SACRAMENTO RIVER AT BOX CANYON DAMSITE (I97O IMPAIRMENTS) (in acre -feet) R\moff Percent ; of average : Year 130 1935-36 8k 1936-37 86 " 1937-38 191 1938-39 192 1939-^0 Ikj i9ii.o-4i 69 19IH-42 50 I9k2-h3 106 19^3-^ 5^ l^-k^ 133 19^5-46 81 1914.6-1+7 63 191+7.1+8 21 19l+6-i+9 125 19^+9-50 81 1950-51 lk6 1951-52 l4l 1952-53 50 1953-5^^ 83 195^-55 30 1955-56 52 1956-57 1h 1957-58 69 1958-59 90 1959-60 : Percent Riinoff : of average 160,000 83 207,000 108 300,000 156 93,000 1+8 255,000 133 363,000 189 296,000 154 162,000 8i+ 121,000 63 161,000 84 164,000 85 lli+,000 59 193,000 100 167,000 87 lll+,000 59 237,000 123 252,000 131 258,000 134 231,000 120 134,000 70 286,000 149 188,000 98 357,000 186 177,000 92 lli+,000 59 1910-11 1911-12 1912-13 1913-14 1914-15 1915-16 1916-17 1917-18 1918-19 1919-20 1920-21 1921-22 1922-23 1923-24 1924-25 1925-26 1926-27 1927-28 1928-29 1929-30 1930-31 1931-32 1932-33 1933-34 1934-35 250,000 161,000 166,000 367,000 368,000(high) 282,000 132,000 97,000 204,000 104,000 255,000 155,000 121,000 4o,6oo(iow) 240,000 155,000 281,000 271,000 97, 000 159,000 58,000 100,000 142,000 132,000 173,000 Average 192,000 100 *As statistically represented by the period I9IO-II through 1959-60. fr, ■-y; ru . TABLE 4 ESTIMATED IMPAIRED MONTHLY RUNOFF OF SACRAMENTO RIVER AT BOX CANYON DAMSITE FOR SELECTED YEARS (I97O IMPAIRMENTS) (in acre -feet) : Probability of Year : exceedence, ; in percent Month March : April ; May ; Jxme ; July : Aug. ; Sept. 1923-24 98 1930-31 96 1958-59 46 1959-60 84 4,850 14,300 3,980 9,l4o 23,600 19,400 l,54o 500 500 500 850 4,260 2,210 500 500 1,270 18,700 6,310 3,450 1,270 2,570 22,600 10,500 1,750 1,420 2,070 -24- as far south as Dunsmuir are all supplied from this ground water storage, ■which regulates nanof f from the accumulated winter precipitation to a constajit rate of flow. The uniform flow of these springs supplies the Sacramento River with a firm base flow at Box Canyon damsite. Both Mt. Shasta City and Dunsmuir derive their water supply from such uniform springs. There also are many individual household wells in the rural areas outside Mt. Shasta City that draw from the abundant ground water. Water Quality Water samples were taken from the Sacramento River above the confluence of Wagon Creek (40N-^-29L) before and during the field investiga- tion for this bulletin. Mineral analyses were made of these samples to determine the concentrations of mineral constituents in the river water. Table 5 shows how these concentrations compare with the recommended limits for concentrations of specific minerals. The water proved to be of a type suitable both for irrigating most crops under most conditions emd for domestic uses. Although classified as slightly hard, the water generally would reqiiire no softening for either domestic or industrial purposes . Determination of the complete suitability of this water for industrial, purposes would necessitate tests for heavy metals (iron and manganese), although turbidity, color, odor, and the total amount of dissolved solids are within tolerances reqviired for most water-related industries. -25- TABLE 5 MINERAL ANALYSIS OF SACRAMENTO RIVER WATER ABOVE THE CONFLUENCE OF WAGON CREEK (Avereige of four seunples) : Recommended limits : Quality of : Irrigation Items : s_ampl( JS : water : Drinking : Range : Average : class I* : water**-* Constituent (in parts per million) Boron 0.03-0.07 O.Oi^ 0.5 Chloride 0.3 -3.3 2.7 175 250 Fluoride 0.0 -0.1 0.0 0.8-1.7*** Hardness 52 -100 75 100 Total dissolved solids 6k -119 91 700 500 Properties Sodium in percent of k -8 6 60 base constituents Specific conductance (Micromhos at 25° C.) 99 -195 150 1000 *Class I irrigation water, as defined by the Departanent of Water Resources, is suitable for most crops xinder most conditions. **U. S. Public Health Drinking Water Standards, I961, hardness excepted. ***Re commended upper limit varies in accordance with the annual average maximum daily air temperature. Trout now live and propagate in all tributaries above the reservoir site. Althovigh no steuadards exist for judging the quality of water required to maintain trout in California movintain streams, studies by the Department of Pish and Game indicate that water stored in Box Canyon Reservoir would support an excellent trout fishery. Water Rights Upstream from Box Canyon damsite there are many farms and rural homes which use water from the Sacramento River and its tributaries. These -26- visers are exercising riparian and appropriative water rights. Very few of these diversions are made xuider licenses or permits issued by the State Water Rights Board. The exportation of water from North Fork Sacramento River to Shasta Valley is made imder a water right license which allows the diversion of 15 cubic feet per second from April 1 to October 10. This export also includes a permit to divert and store 350 acre-feet during the period October 1 to May 15. An application for ^9 acre-feet of storage on Wagon Creek and ^9 acre- feet of off stream storage in Metcalf Lake was approved by the State Water Rights Board in November I961. Water for this storage will be diverted during the winter months. The impairments cited in Table 2 account for the decrease in water supply available for Box Canyon Reservoir as a resxilt of upstream diversions. The storage of sujrplus waters in the proposed Box Canyon Reservoir would not interfere with upstreeun water rights. Between the Box Canyon damsite ajid Shasta Reservoir there are many riparian owners, but there is very little storage, diversion, or use of Sacramento River water. Applications to permit storage of water in Shasta Reservoir were filed in 1927 by the State of California and were eissigned to the Bureau of Reclamation in 1938* Included in the assignment to the Bureau of Reclamation is a clause reserving water to upstream counties of water origin for their future requirements. This reservation would permit the depletion of inflow to Shasta Reservoir by 700,000 acre-feet in any one year, but not to exceed 4,500,000 acre-feet in any ten- year period. Future reservoirs, such as Allen Camp Reservoir on the Pit River proposed by the Big Valley Irrigation District, and the McCloud River power development plan which the Pacific Gas and Electric Company proposes to build, would increase storsLge above Shasta Reservoir by only 215,000 acre-feet. Even -?7- if Box Canyon Reservoir, with a capacity of 30,000 acre-feet, were conrpleted in the same year as Allen Camp Dam and the McCloud River Development, the Increase in upstream storage would "be far less than the allowable depletion to Shasta Reservoir inflow. -28- CHAPTKR III. INVESTIGATION OF SEPARABLE PROJECT PURPOSES After reconnaiscince showed that the possible multipurpose features of a reservoir project at the Box Canyon site would be recreation development, flood control, hydroelectric power generation, and water conservation for agricultural, municipal and industrial purposes, each purpose was studied to determine its necessity, its engineering features, its cost of inclusion in the project, and its potential benefits. The economic justification for inclusion of any purpose in a project requires that benefits derived from the purpose at least equal the cost of including the purpose in the project. Economic justification studies considered only the costs of adding specific facilities to the project. Preliminary studies showed that a reservoir with a storage capacity of approximately 30,000 acre-feet and a surface area of about 500 acres would be satisfactory for all multipurpose uses. In general, no costs of increasing reservoir storage capacity were included in the estimates of separable costs. This chapter describes the analysis made of each purpose and the means used to determine whether inclusion of the purpose in the project would be justified. Recreation The demand for outdoor recreation facilities increased sharply in California during the years following World War II. This increased demand is attributed mainly to the rapid rise of California population, an increase in leisure time, a higher income per capita, improved transportation, and technological advances in recreation equipment. The California Public Out- door Recreation Plan, published in I960, assesses the recreation needs of the people of the State and points out that the demand for outdoor recreation -29- areas and facilities in California is far greater than the present supply. According to basic recreation data collected for this bulletin, potential users of organized recreation areas in the Box Canyon vicinity presently are turned away and will continue to be turned away in the foreseeable future because the donand for facilities will stay ahead of supply. The environment of the Box Canyon area is exceedingly suitable to recreation. Surrounding the tentative reservoir would be an area of Southern Siskiyou County noted for its spectacular scenery. The high snow-covered mountains, vast coniferous forests, mountain lakes, streams, and rivers support big game, uplsind game, and trout fisheries. The public enjoyment of the scenery, and the attractive summer climate at this site would be greatly enhanced when coupled with recreation facilities and the opportunity for good fishing, hunting, and water contact sports. The "Mt. Shasta-Siskiyou Area Study", completed in January 1962, by the California Department of Parks and Recreation, Division of Beaches and Parks, presents an analysis of the state park potentials in Western Siskiyou County, During the study, it was determined that a Box Canyon Pix)ject was one of five projects sioitable for inclusion in the California State Park System, The following statement about a Box Canyon Project was extracted from the report: ■. - "High quality family camping, together with opportunities for enjoyment of the primitive mountain Icinds to the south and west in «•' ' the Shasta-Trinity National Forest, are the principal recreational resources, and in themselves will justify the creation of a State /Park_7 Unit. ^owever_7, creation of a 500-acre recreational reservoir by the construction of a dam at Box Canyon would greatly increase the recreational potential of the area and lead to consider- ably heavier attendance." It was recommended in the report that the Box Canyon Project be adopted as an official project of the State Park program, and that additional detailed planning and studies be performed pending the availability of funds for its -30- acquisition and development. The California State Park Conunission approved the recommendation and requested that additional studies be included in the 1962-63 planning program. In the Mt. Shasta City-Dunsmuir Area Investigation, estimates of present recreation use and future recreation demand at Box Canyon were made to determine benefits, required project features, and costs. Estimates of recreation demand "without a project" assume that recreation facility development would continue to take place at the local level. Estimates of recreation demand "with a project" throughout the assumed 50-year economic life of the project are based on the following assumptions: o Recreation facilities reqviired to supply the demand would be installed, ° The length of recreation season at full use level would be 100 days. o Box Canyon Reservoir, with a surface area of about $00 acres and appropriate facilities for all uses, would be available. Estimates of recreation use and recreation demand were made in terms of visitor-days. A visitor-day represents each day or portion of a day that each recreationist spends at the project site in connection with water-associated recreation activities. Recreation benefits were based upon net visitor-days. Net visitor-days are those attributable to the project and are computed by subtracting the number of visitor-days that would occur in the future without a project from the number that would occur with the project. Primary recreation benefits were then computed by m\iltiplying net visitor-days times the appropriate dollar value accruing to the users. To facilitate predictions of recreation demand, benefits, and subsequent costs of recreation facilities at Box Cainyon, recreationists were classified as campers, day-users, and sightseers. The following discussion concerns predictions of recreation demand created by each category and the facilities required to supply that demand. -31- Campers Camping parties wo\ald stay overnight and utilize project camping facilities. Camp units provided would be of state park standards and generally consist of a fireplace, table, cupboard, parking area, tent space, and water and sanitary facilities shared by several units. The location of Box Canyon in relation to population centers and the types of recreation activities suitable for development indicate that camping would attract the largest number of recreationists to the area. The family campground would be a hub from which activities such as boating, fishing, swimming, and hiking would originate. Camping Use Without Pro.ject . Mt. Shasta City owns property at the confluence of Wagon Creek and the Sacramento River where campers may use an unimproved area. The city has considered future construction of about 14 camp sites on this unimproved area. At present (1962), in the same vicinity one privately owned campground of approximately eight units is open to the public but has not experienced heavy use. The low use probably reflects lack of public knowledge of its existence. Although other areas along the river are suitable for camp sites, a very small amount of camping takes place annually because no facilities are available. Therefore, for the purpose of this study the amount of camping use in the project area was assumed to remain negligible unless a project offering good facilities were constructed at the Box Canyon site. Camping Use With Project , The number of potential camper visitor- days at Box Canyon Reservoir was estimated by analyzing historical use data from MacArthur-Bumey Falls State Park after examination of other areas providing camp facilities in the region showed that this park was most similar to Box Canyon. In fact, these two camping areas would be almost identical in elevation, temperature, topography, soil type, vegetative types, length of recreation season, proximity to a water body, and distance from large population centers. The MacArthur-Bumey Falls State Park lies in Shasta County on State -32- Highway 299, approximately 60 miles southeast of Mt, Siasta City. Illustration 3 shows the similarity of topography and vegetative types in the two areas. Because of these similarities, it was assumed that, had the Box Canyon site been developed as proposed, potential camping use in the area during I960 woxild have equalled camping demand at MacArthur-Bumey Falls State Park during the same year. Estimates of camping demand at Box Canyon for the period from i960 throijgh 2020 assiimed, therefore, that the I960 camping demand at Box Canyon was U5,000 visitor-days because this was the camping demand which analysis of recreation season records showed existed duiing I960 at MacArthur-Bumey Falls State Park. Demand projections for years subsequent to I96O were made by assuming that camping demand will increase in direct proportion to the expected increase in California population and, additionally, will reflect increased per capita participation in outdoor recreation. Such per capita participation in outdoor recreation was estimated from historical trends and is assumed in this report to increase throughout the study period at the rate of 2 percent of the initial use per year. Recreation use duiing the first ten years was modified in accordance with an analysis of recreation use data from Millerton State Park which indicates that two-thirds of the use in the tenth year of project operation would occur in the fifth year. It was therefore assumed that during the first decade of opera- tion. Box Canyon Reservoir would experience this same pattern of visitation. Consequently, in addition to the normal increase in use due to popiilation and participation in outdoor recreation, the estimate of use during the first decade of operation was adjusted to correspond to the historical use pattern at Millerton State Park, Figure 2 shows annual projected camping use at Box Canyon between 1970 and 2020. Camping Facilities . Criteria used to determine the number of camp facilities required to supply the predicted demand at any time during the economic life of the project were as follows: -33- Beach at Lake Brit ton, MacArthur- Bumey Falls State Park ■-■' '^f^,,: "ii^' •'■■ J. Box Canyon reservoir area from possible beach site Beach Sites at Lake Britton and Box Canyon a: < >- a: < o u. o o X 700 600 500 400 300 200 100 I960 2020 Fig. 2. ESTIMATED RECREATION USE AT BOX CANYON RESERVOIR SITE " 600 / CUR\ /E 3 1 1 1 1 1 CURVE 1 - Number Of Units Required / CURVE 3-10 Percent Overdeveloped / ' / CURVE 1 / / 1 / 7 / CUR\ E 2 UNIT , INSTA -LEO — t) /, / / 7 / / / // / 125 / / // / / ' / / /; ■ / / ^ / / ' / / /„/ / / '/' / y / 75 / / / ^ /^ ^ ^ '// I960 1970 1980 1990 2000 2010 2020 2030 2040 YEAR Fig. 3. STAGING OF CAMP UNIT INSTALLATION AT BOX CANYON RESERVOIR o One camping party uses one camp site for one day and one night. o The average camping party is composed of 4.2 people. o Thirty-five percent of the total annual use of camping facilities occurs during the peak month of use, o Camping facilities should meet the average daily demand during the peak month of use, o An overload of ten percent during the peak month of use would be allowable before additional facilities would be installed. Computations using these criteria resulted in the curves presented in Figure 3o Curve 1 shows the number of camping facilities required for predicted demand during the entire study period. Curves 2 and 3 were used to develop limits in staging the installation of camping facilities, and show limits for installing new project facilities whenever the demand exceeds the capacity by ten percent, Day-Users Day-users include fishermen, power boat enthusiasts, and beach users. Although day-users do not stay overnight, some are picnickers who use available picnic facilities. The California Public Outdoor Recreation Plan, cited earlier, reports that most day-use parties at recreation areas originate from within a maximimi radius of 70 miles and an average of 35 miles from the recreation site, distances indicative of one-day excursions. By these figures, the Counties of Siskiyou, Lassen, Modoc, Shasta, and Tehama lie within the Box Canyon day-use area, Day-Use VJithout Pro.ject . Present day-use within the project area consists almost entirely of stream fishing. There is very little picnicking and no boating. Youngsters from Mt. Shasta City have fashioned a small "swimmin' hole" near the city's campground site by piling stones into a dam across the Sacramento River. A farm pond in the project area also is used -36- for swimming. However, total use of "both of these svn.raming areas is rela- tively small. During trout season, the State Fish Hatchery at ^Jt. Shasta City supplements the native trout population which resides in the Bo:>: Canyon Reservoir area with weekly plantings of catchable-sized rainbow trout in the Sacramento River and Wagon Creek. These catchables attract the many fishermen who make up the bulk of the nonproject day-users. Surveys conducted during i960 and 1961 by the Department of V/ater Resources and the Department of Fish and Game resulted in the estimate that present annual day-use (including svrLmraers) in the project area amounted to 9^000 visitor-days. Using this estimate as a beginning point, future day-use without a reservoir -jiras estimated for the period from I96O through 2020. Projections assumed that use would increase in direct proportion to the expected increase in population of the Counties of Siskiyou, Lassen, Modoc, Shasta, and Tehama, and utilized the annual rate of increase in per capita participation in out- door recreation which was developed for csunping use projections. Figure 2 shows the projected day-use without a project. Day-Use VJith Project . Recreation facilities and a reservoir \in.th a stable v/ater surface at Box Canyon would provide many opportunities for day- use activities which do not presently exist in the area and would enhance further those activities presently enjoyed. Good s-^>n.mming, beaches, boating areas, a launching reiriTp, picnic facilities, and an excellent reservoir fisher;y" would become available under project conditions. Following analysis of both population distribution and the results of a recreation survey conducted at D-r^innell Reservoir in Shasta Valley in 1958, potential day-use for I96O under project conditions at Box Canyon was estimated at 13,000 visitor-days. The reasonableness of this estinate was -37- checked by comparing it to the visitor-days of use experienced by several newly developed reservoirs. The a?ea within 15 miles of the project includes the Cities of Mt. Shasta, Dunsmuir, McCloud, and Weed, and has a total population of about lUjOOO people. An annuail day- use rate of one visit per c^ita from this combined .population would result in lUjOOO visitor-days of day- use at Box Canyon. The estimate of 13,000 visitor-days for I960, if a reservoir had been available at Box Canyon, appears conservative. The i960 estimate d^-use of .the Box Canyon area with a project was used as a starting point to estimate day-use to the year 2020. Such estimates used the same method of increasing day-use in proportion to the population increase of Siskiyou sind neighboring counties, and in proportion to the increase in per capita participation in outdoor recreation. Figure 2 shows day-use, visitor-day projections with a reservoir. Day-Use Facilities . Comparison of the tentative Box Canyon Reservoir with similar reservoirs and interpretation of the 1958 recreation use sui^ey at Dwinnell Reservoir resulted in the following estimated percentages of day-users who would participate in various activities at Box Canyon: ° Fishing: UO percent ° Boating and water skiing: 20 percent ° Swimming: 20 percent Picnicking: 20 percent Fishing was assigned to be the most attractive day-use activity because of the high potential of Box Canyon as a trout fishery. Boating and water skiing may not be as popular here as elsewhere because of the limited size of the proposed reservoir, as compared to the large surface areas of other reservoirs in this section of the State. Adequate zoning of the reservoir should be provided to prevent conflicts in use. -38- Picnic units to be provided generally would consist of a fireplace, table, and parking area. Water and sanitary facilities would be shared by several units. All units would meet state park standards. Criteria used to deterinine the number of picnic iinits required to supply the predicted demand at any time during the economic life of the project were as follows; ° One and three- fourths day- use parties use one picnic unit daily during the peak month of use. ° The average day-use party is composed of i;.2 people. ° Picnic units should provide for all picnickers, one- quarter of the boaters, and incidental use by fishermen and swimmers. ° Picnic units should meet the average daily demand during the peak month of use. ° An overload of 10 percent during the peak month of use would be sillowable before additional facilities would be installed. Computations using these criteria resulted in the curves presented in Figure h* Curve 1 shows the number of picnic facilities required for predicted danand during the entire study period. Curves 2 and 3 were used to develop limits in staging the instcillation of picnic facilities. In addition to picnic facilities, a boat launching ramp, beach areas, sanitary facilities, bathhouses, and parking areas would be provided for day- users. Sightseers Individuals in this category would be in the area only a short time and would make use of overlook vistas, parking areas, and sanitary facilities installed at project expense. They would also utilize any concession facilities available. -39' 350 / CURVE 3 CURVE 1 - Number Of Units Required / CURVE 1 CURVE 3-10 Percent Overdeveloped f y / // CURVE 2 90 r. / / 7 // / } / J 50 f / 7 / / /.< 4 'l> UNIT i INSTA LEO — -»L ^ 7 ^' / '^' .^ y^ -y^ X ''^ ^ 2000 YEAR Fig. 4. STAGING OF PICNIC UNIT INSTALLATION AT BOX CANYON RESERVOIR Demand for Sightseeing , An average of 27 percent of the recreation visitors to 18 projects reported in the 1958 sximmation of U, S. Bureau of Reclamation recreation data were sightseers. At Friant, Folsom, Sly Park, Stony Gorge, and Cachuma Reservoirs in 1959, an average of 28 percent of the recreation visitors were sightseers, according to additional data supplied by the bureau. The Mt. Shasta-Skiskiyou Area Study, published in January 1962 by the California Division of Beaches and Parks, states that sightseers represent approximately 50 percent of the recreationists in District I, which includes the Counties of Shasta, Siskiyou, Trinity, Modoc, Lassen, Del Norte, Humboldt, and Tehama, as well as part of Mendocino County. -40- Sightseer use of Box Canyon, however, probably will most nearly approximate the U. S. Bureau of Reclamation averages at reservoir projects because Box Canyon will more nearly represent this type of recreation area than those with outstanding natural attractions such as MacArthur-Bumey Falls or Castle Crags State Peirks in Shasta County. Therefore, it was estimated that in addition to the campers and day- users, sightseers numbering 25 percent of the total recreation use would also visit Box Canyon Reservoir. These are considered to be net sightseers since present sightseeing use is negligibxe. Facilities for Sightseers . A desirable location for a vista over- looking the Box Canyon Reservoir is shown on Plate 3, "Recreation Land Use Plan." Cost estimates for recreation facilities include the development of this vista as well as that of a parking area and sanitary facilities. Summary of Recreation Use Table 6 summarizes estimates of recreation use with and without a project in terms of visitor-days of use by the three defined categories of recreationistst campers, day-users, and sightseers. Recreation Benefits As has been stated, recreation benefits of a project are determined by mxiltiplying the number of net visitor-days attributable to the project times the dollar value of a visitor-day. The dollar value of a visitor-day to campers and day-users at Box Canyon Reservoir would be $2.30. That to sightseers would be $0 cents, in accordance with the minimum value, believed to be conservative, set by the Department of Water Resources for recreation benefits. The "Consumer's Surplus" method, described in Appendix A, Bulletin No. 59-2, "Investigation of Upper Feather River Basin Development," was used to obtain the dollar value of a visitor-day to campers and day- users. -Ui- As applied to recreation, a consumer's surplus occurs when some people pay- more than others for the same recreational pleasure. To compute the size of this difference or surplus, travel costs are assigned to expected visitor origins. The difference between the median travel cost and that cost below which 90 percent of the visitor-day expenses occur, constitutes the consumer's surplus or visitor-day value. Estimates of travel cost per visitor-day utilized data gathered during field investigation at MacArthur-Burney Falls and Castle Crags State Parks. Such data included the number of people in each party, the area of origin of each party, and the nimber of days each party spent in the area. A figure of 72 cents per mile was used as the average travel expenditure. Project recreation benefits were computed first as the totals accruing during each decade of a 50-year repayment period using the projected net visitor-day values previously discussed and the value of $2.30 per visitor- day for campers and day- users and that of 50 cents per visitor-day for sightseers, The total benefits for each decade were then reduced to present worth values at the beginning of the project to express benefits in the same financial terms as total costs. A summary of this procedxire presented in Table 7 shows that the present worth value of total recreation benefits at the proposed Box Canyon Reservoir vovild be $9,1;70,000. Recreation Costs As previously stated, a reservoir with 30,000 acre-feet of storage capacity and a surface area of about 500 acres was considered to be satisfactory for all proposed project purposes. Therefore, the estimate of separable recreation costs was based on the cost of adding camping and picnicking facilities, a boat laixnching ramp, access roads, and sightseeing facilities. -1;2- u O CY a. 7. 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CO o o .- D o o^ o- a c o t— .— .— .— CNI CN -43- Estimates of the cost of camping and picnic facilities were made using average cost figures supplied by the Division of Beaches and Parks. The value of $3,000 per unit for camp and picnic sites includes the costs of developing the site, of installing tables, fireplaces, and cupboards, and of sanitary facilities, vater supply, and access roads within areas containing 50 camp and picnic sites. Additional costs were added to provide for develop- ment of water supply sources, main access roads, beach improvement, and boat launching ramps. Annual operation, maintenance, and replacement costs were computed on the basis of kO cents per visitor-day for all recreationists. Total costs of installation, operation, maintenance, and replacement are presented in Table 8. The 1970 present worth values of cost of recreation facilities, operation, maintenance, and replacement are presented in Table 9. The present worth value of total recreation facilities costs would be $4,107,000. Economic Justification When reduced to a comparable basis of present worth values in 1970, benefits and the separable cost of the recreation purpose of the Box Canyon Project have been estimated at $9,^70,000 and $4,107,000, respectively. Because recreation benefits exceed separable recreation costs, recreation may be included as a purpose in the Box Cajiyon Project. Consideration of possible alternatives in or near the Mt. Shasta City- Dunsmuir Area did not reveal another water development project that would fulfill the recreation demand estimated for this area to the extent described for the Box Canyon Project. Flood Control Economic justification of including flood protection works as a pu2rpose in the proposed Box Canyon Reservoir was investigated by comparing the costs of aa Eh «0 ►J n o <: O M -a; o o o x; o DD O CO E-" tn o o o X o CQ o E-i en 1 CO 4-) -p OOOOOOOQOQQOQQ QOOQQQQOObooQQ oooooooooo^oooo 8 o CO CO a; -P •H c -P tn ^4 •» o O 0) o txTt-^Li^C J^OtXJOOCNiCOCVrHO r- •H (0 e-i i^ s sOCM'^C^tMrHOrH'^O -J-tX) C^-;f o -p I. a OOJrHr^rHC~^rHC^rHr^rHrV(Hr^ r-i eti rt J 0) 1 — 1 •" *• ** *" 1—1 o T3 ^ -p m -p O O Q Q O O Q 8 8 8 8 8^ 8 8^ O 4) #v :|c CO ;< •V C 0) >(« (D o £> C^ O O c>; OJ O c^ rH •M o in U n CM C^ rH H O tXI ^ rH li C -P a, CNi r^ 0^ c^ c^^ c\ c^ r-t • Oj CO •« •• •s to c o a> cv U (U o •H +J •5 cd O Q O O O O O o -P C -P •H -H C ^£ Q Q O Q O O Q O O O O O O O ^ rH CD 0) •\ C~- iJ^ xO TO -t 73 1 Cfl •> O CV -4^ ir\ C^ C7^ rH O ^ tM c n) O rH O E-" r^ c>r O -P C -H a • « •• O O O O Q Q O Q O O Q O Q Q O O O O O S O •H O -P 0) •H rt ^H rH CO -p ^ rt •^ •X ^ PV ^ •» A n) 0) -o ;3 O C^ CNJ C- C^ CO -^ -J TO vO TO rH g 10 o u 5 sO ^ TO O u-\ -4- C^ -p -P O a. O r-f r-i r-i r-i r-{ r-\ CJN -P rH +j ■r^ a 3 a. -p #N C^ MS •« V^ V^ *V Q. a o TO rH -4 r- C^ rH O •-0 O O i-\ c-\ CO e E. c ^^ •H -H (fl i^ c^ c^ c- c^ r- o -p CO o E-. +^ <1> H o C >j •H CT) -p * ' 3 tH C XI c O 0) o '^ H C> y^ oi O ^ H 0) E-" rH i/\ O "^ O O ir\ o o CTJ O vO >^ O c^ Q C^ CSi fT> ~4 "> r~- CT^ rH c^ +J •-\ o •* •> H -- rH O 1^ '^ O O O O uS sO TO CNi vO rH O o ^ ■p o o rH rH CM OA ro H ^ • • •• O •o •H c o •H 0) rH O 1^ O 1^ O O Q Lf\ rH CNJ r^ -J- "^ O^ 1 CO Ph ■P -P CO •H C M CM CM ir\ u\ a C) O ^^ O o a) C O i" t£ ■H -P -J- O C-- C^ C^ O C^ r- 3 3 +J O CM CM en -4 u^ vO TO TO O O cfl * H 0) a, •* •* ^ E •• •. cn -J- o c3 TD (B CJ 0) (1) ID aj rH Lp> o ^/^ O O '^ '^ -4 ^^ :^ o o cNj c~- J-. U rH 1 bO aO cd fV rH rH rH rH -p •H -H CO Cr. bn c l-H e s O O II o "^ c^^ o --o m o o t. f^ CO C~- C^ TO TO CT^ Q rH O O OS CJ^ O O O CM t "^ H rH rH rH rH rH CM CM C\i -1^5- providing protection to the benefits of flood damages prevented. The benefits must be greater than the cost of providing protection to permit justification of the protective works. Areas of Historical Damage Past flooding of the Sacramento River has caused serious damage do-vm- stream from the Box Canyon damsite in the areas shown on Plate 1. Canyon walls along the reach of the river between the damsite and Shasta Lake are steep and only small amounts of flat flood plain occur at intervals alorg the river. Various measures for flood protection have been attempted in some of the developed areas in the flood plain, but much of the area remains subject to repeated flooding. The City of Dunsmuir has experienced flood damage to streets and sewer lines, and the levee around the se-vra,ge treatment plant has suffered severe damage twice in recent years. Private residences and business establishments also have been damaged by flood ivaters. Floods also have damaged Castella, located at the confluence of Castle Creek ajid the Sacramento River. Most of the damage here has been to business establishments and private residences. The main line of the Southern Pacific Railroad follows the course of the Sacramento River throvigh the cajiyon from Shasta Lake to the Cantara Loop about 2 miles below Box Cemyon damsite. During periods of severe flooding, bridge damage and track washouts have occurred at several places along this portion of the line. Flooding of the Sacramento River has damaged roads and bridges in the Dunsmuir-Castella areas of Siskiyou and Shasta Counties. -46- Present Flood Protection Works Most of the existing flood protection works along the Sacramento River in the Dunsmuir-Castella area have been provided by local residents and agencies. However, the federal government supplied fiinds for some channel improvement and repair of damaged levees following the floods of 1955 and 1958. Many private residences in Dunsmuir and Castella are built right on the banks of the river. In order to protect their homes and properties from flood waters, many property owners have built retaining walls to restrain the river. The Southern Pacific Railroad has constructed a large concrete wall along the west bank of the river in Dunsmuir to protect its rail yard. Following the flood of 1940, in which flood waters overtopped the east bank and damaged several homes and businesses in Dunsmuir, the city constructed a concrete retaining wall which contained both the 1955 and 1958 floods. However, during the 1955 flood the water is reported to have risen to the top of the wall. A levee around the seepage ponds at the Dunsmuir sewage treatment plant was reconstructed following damage during the 1958 flood and appears to be sufficient to restrain a flood similar to the one which occurred in 1940. Illustration 4 pictures this levee. Other smellier levees have been constructed in Dionsmuir in an attempt to avert future damage. Following the 1955 flood, funds obtained from the federal government were used for channel cleaning and improvement along the Sacramento River just downstream from the U. 3, Highway 99 bridge at Dunsmuir. These improve- ments have increased carrying capacity of the channel and lessened the possibility of flooding in that area. Benefits From Flood Control The benefit from flood protection is expressed in terms of the esti- mated average annual flood damage which would be prevented by the project. -kS- Estimated Historical Damages. A survey of historical flood damages in the areas delineated on Plate 1 was made to aid in determination of the annual flood damage. Three major floods have occurred in the last 20 years for which some damage estimates were available. The greatest flood of record, during the past $0 years, occurred in February 19U0, and was followed by floods in December 195>$ and February 19$8. Several reliable estimates of damage are available for the floods of 1955 and 1958, but information concerning the 19liO flood damages is difficult to obtain. Table 10 presents a summary of estimated damages to residential areas, commercial establishments, agriculture, industry, utilities, and public facilities in the Dunsmuir-Castella area during the floods of 19U0, 1955, and 1958. Estimated Future Damage . Future flood occurrence was based on a statistical analysis of the frequency of past flooding during the period of record (1910-1960). Table 11 shows the probability of exceedance, or the percent of time, that annual flood peaks are expected to exceed various flood magnitudes ranging from UOO to 15,000 second- feet. Table 11 also shows the estimated monetary damages, as obtained from a flood damage curve, for floods of various magnitudes. The flood damage curve was constructed follo^ving analysis of the probabilities of exceedance of floods of various magnitudes, and estimates of past and future flood damage. Predictions indicated future flood damage would result whenever flows in the channel past Bunsmuir exceeded 5,000 second-feet and overtopped existing local flood protection structiires. If full protection from all floods up to those with intervals of 100 years is assumed, average annual flood damage during a 100-year period would be $5,500. This relatively low damage may be attributed mainly to three factors: ° Total damages experienced in recent floods in the flood plain are comparatively small. -U9- TABLE 10 ESTIMATED HISTORICAL SACRAMENTO RIVER FLOOD DAMAGE TO DUNSMUIR-CASTELLA AREA Flow at Date : Dunsmuir , Flood damages. in second-feet in dollars March 19^0 11,800 55,000 December 1955 9,6oo k6,000 February 1958 8,500 33,700 TABLE 11 ESTIMATED SACRAMENTO RIVER FLOOD DAMAGE TO DUNSMUIR-CASTELLA AREA AT SELECTED ANNUAL PEAK FLOWS Annual peak flow : Probability of : Estimated annual at Dimsrauir, : exceedance. : flood damages. in second-feet : in percent : in dollars Uoo 100 _-- J+,000 3h 5,000 23 6,000 15 7,000 7,000 11 15,000 8,000 7 26,000 9,000 5 if 1,000 10,000 3.6 W,000 11,000 2.7 52,000 12,000 1.8 55,000 13,000 l.U 57,000 llf,000 1.0 105,000 15,000 0.75 110,000 ■50- o The occurrence of damaging flood flows is relatively infrequent. o Locally constructed flood protection works prevent damage that in the past occurred from small, frequent floods. Flood Control Benefits . Flood control benefits attributable to a project are defined as the amount of flood damages prevented by the project. Therefore, if all dajnages from floods with recurrence interval up to 100 years are prevented in the Dunsmuir-Castella area, the average annual benefit attributable to the project would be $5j500. Cost of Flood Control The cost of a reservoir used for flood control is dependent upon the cost of providing sufficient storage capacity for flood control and release facilities beyond the normal facilities required in a reservoir not used for flood control. '*■' ^' Flood Control Requirements . Control of floods with a reservoir is accomplished by reserving during the flood season a portion of the reservoir storage capacity to store flood water. Following the flood threat, flood water stored can be released in a steady nondamaging flow. Analysis determined the flood control features and operations that _^- would have to be incorporated in the proposed Box Canyon Reservoir to meet the flood control requirements. The probabilities of exceedance of floods at the damsite and at Dunsmuir were estimated by correlation with the probabilities of exceedance measured at other stream gaging stations on the Sacramento River. Table 12 presents magnitudes of flows estimated for various probabilities of exceedance at Delta, Dunsmuir, ajid at Box Canyon damsite. The nondamaging channel capacity at Dunsmuir is estimated to be 5,000 second-feet. The dradnage area of Box Canyon damsite is 122 square miles, and the drainage area of the Sacramento River above Dunsmuir is l6l square males. Table 12 shows that the peak flow at Dunsmuir is about 50 percent -51- TABLE 12 ESTD'IATED ANl>iUAL FLX)OD PEAKS FOR SACRAI^IENTO RIVER ABOVE DELTA GAGING STATION Probability of : Annual peak flow, in second-feet exceedance. : Box Canyon : Dunsrauir : Delta gaging in percent : damsite : : station 50 2,000 3,100 13,000 20 3,500 5,300 23,000 10 4,700 7,100 31,000 5 6,000 9,000 38,000 2 7,800 11,800 50,000 1 9,300 14,000 60,000 TABLE 13 FLOOD CONTROL ACCOMPLISHMENT OF 15,000 ACRE-FOOT FLOOD CONTROL RESERVATION AT BOX CANYON RESERVOIR Probability of exceedance. Peak inflow to reservoir, in second-feet Maximum discharge ' from reservoir, in second-feet t Annual peak flow : at Dunsmuir, : in second-feet in percent : Uncontrolled: With pro.iect 4 6,200 2,000 9,300 4,700 2 7,800 3,000 11,800 5,000 1 9,300 4,000 14,000 5,000 0.1 15,000 15,000 23,000 23,000 -52- greater than the peak flow at Box Canyon damsite. Because of this. Box Canyon Reservoir could control the flow at Dunsmuir only partially. In the case of a flood with a recurrence interval greater than 1-in-lOO years, the inflow between the dam and Dunsmuir may be 5,000 second-feet — equal to the channel capacity at Dunsmuir. Trial flood control operations determined the reservoir storage capacity reqxiired for control of floods of various magnitudes. The following operating criteria were used: o During the flood season (about October 1 through April l) a given flood control reservation would be maintained by releasing all inflow, o As flows increased during a flood, the release at Box Canyon Reservoir would be increased until the discharge at Dunsmuir reached 5,000 second-feet and thereafter manipulated to limit the discharge at Dunsmuir to this amount; excess flood waters would be stored in the reservoir. o During recession periods following a flood, stored flood waters would be released to regain the flood control reservation as rapidly as possible without exceeding the channel capacity at Dionsmuir (5,000 second-feet). With a 10,000 acre-foot flood control reservation, a flood at Dunsmuir of 11,800 second-feet (l-in-50-year flood) could be reduced, under this method of operation, to the required 5,000 second-feet. However, a flood at Dunsmuir of 14,000 second-feet ( 1-in-l 00-year flood) could be reduced only to 10,000 second-feet, 5,000 second-feet in excess of the channel capacity at that point. A flood control reservation of 15,000 acre-feet would be re- quired to reduce such a flood to the required 5,000 second-feet and the rate of release from the reservoir would have to be 4,000 second-feet. Partial control could be accomplished with a smaller flood control reservation and a smaller release rate. Table 13 demonstrates the flood control accomplishment at Dunsmuir with a 15,000 acre-foot flood control reservation in Box Canyon Reservoir, -53- Cost of Flood Control Facilities o This analysis assumed that a multipurpose Box Canyon Project would be constructed to a capacity of 30,000 acre-feet and that a 15,000 acre-foot flood control reservation would be maintained from October 1 through April 1, Operation of Box Canyon Reservoir for flood control purposes would require that the outlet works be enlarged to 4,000 second-feet from the 300 second-foot capacity required for maintenance of the downstream fishery and emergency drawdown of the reservoir for the safety of the structure. The cost of the larger outlet works in excess of the smaller represents the cost of adding flood control to the list of project purposes. No cost was assigned to the reservoir storage capacity necessary to maintain the flood control reservation. Assigned costs are shown in the following tabulation: o Estimated cost of outlet works for flood control: $500,000 ° Estimated cost of outlet works for stream maintenance: $200,000 o Estimated added cost of flood control facilities: $300,000 The equivalent average annual cost of a capital investment of $300,000 is $14,000, assuming cin amortization period of 50-years and annual interest at four percent. Economic Justification The average annual benefit derived from providing a measure of flood control to the Dunsmuir-Gastella area by storage and regulated release of flood flows at Box Canyon Reservoir was estimated at $5,500. The average annual cost of facilities required to prevent flood damage was estimated at $14,000. Because costs of added flood control features exceed benefits, flood control as a purpose in the Box Canyon project is not economically justified and should not be included in final project formulation. -54- Hydroelectric Power The possibility of generating hydroelectric power by release of water stored in a reservoir at Box Canyon was considered by the California-Oregon Power Company (now Pacific Power and Light Compauiy) in the 1950' s. Similar plans investigated by the Department of Water Resources are discussed in Bulletin No. 3 "The California Water Plan, 1957." Both of these investigations were based on a project whose primary purpose would have been power generation. Both plans would have exported water from a reservoir at Box Canyon to be used for power generation in a series of power plants in the McCloud River system. In the Mt. Shasta City-Dunsmuir Area Investigation, the possible inclusion of hydroelectric power generation as a purpose in a multipurpose project at the Box Canyon site was studied. Results of this study are presented in the following sections. The Power Market Until its merger in 1961 with Pacific Power and Light Compamy, the California-Oregon Power Company supplied electrical power to the Mt, Shasta City-Dunsmuir area. Pacific Power and Light Company presently supplies this service. During the present investigation, however, no information as to the power loads and resources of the Pacific Power and Light Company was avail- able. Power market studies, therefore, utilized data pertaining to the California-Oregon Power Company, These studies showed that, by 1968, the California-Oregon Power Company would need power in addition to that provided by its available hydroelectric resources. The most likely source of such additional power would be through purchases frx)m the Pacific Gas and Electric Compauiy, Because the value of potential energy from Box Canyon Reservoir is based on the cost of energy from the most likely alternative source, it was assumed that power from the reservoir could be sold at the rate that the Pacific ■55- Gas and Electric Company charged the California Power Company for electrical energy in I960. The I960 contract rate is as follows: dependable capacity component, $19 .SO per dependable kilowatt per year; and energy component, 3.35 mills per kilowatt-hour. Box Canyon Hydroelectric Power Potential Studies were conducted to attain the maximum economic development and utilization of the power resources at Box Canyon damsite. The powerplant was located at streambed elevation (2,900 feet) at the lower end of Box Canyon to take advantage of the additional 100 feet of head made available by the difference in elevation between this point and the damsite. A power canal and penstocks would convey water from the reservoir to the powerplant. The hydro- electric power production studies involved the coordinating and combining of the proposed Box Canyon powerplant into a fully coordinated and integrated power system in the northern part of California and southern part of Oregon. The period of study covered a hydrographic cycle from 1910 through I960. The average annual energy production based on the historic runoff (I9IO-I96O) was estimated to be 20,000,000 kilowatt-hours. The critical adverse water period for power production begins in July 1923, and continues through February 1925. The potential energy available during the critical period was estimated to be 1$, 000, 000 kilowatt-hours per year. The capacity factor of hydroelectric power in an adverse water year determines the dependable capacity of the plant. Substantially all of the system hydroelectric capacity is operated in the peak of the load, and practically all of the hydroenergy of each plant is required to make the plant capacity dependable in supplying that segment of the load to which it is assigned. Based on dry year hydrologic conditions and an annual capacity factor of U2.5 percent, the dependable capacity of the proposed Box Canyon powerplant was estimated to be li,000 kilowatts. -ti6- The power production estimates are based on a reservoir and facilities with the follovring characteristics: Maximum reservoir storage: 35*000 acre- feet Minimum reservoir storage: 5,U00 acre-feet Average net head: 290 feet Overall efficiency of powerplant: 80 percent implying the power values as indicated in the preceding section to the estimated power accomplishments of U^OOO kilowatts of dependable capacity and 20,000,000 kilowatt-hours, the power benefit would be $lU6,200 annually. Cost of Power Facilities A power development at Box Canyon damsite would require the following major facilities: ° Powerplant (U,000 kilowatts) located at the lower end of Box Canyon and approximately 5,000 feet downstream from the dam. ° Pipeline (approximately 5,000 feet long; leading from an outlet in the dam to the penstock of the powerplant. ° Siirge tank ° Penstock (approximately 600 feet long) ° Small dam located downstream from the powerplant and constructed to form an afterbay for regulation of downstream releases. The capital cost of the powerplant was estimated to be $8l6,000. Other features, including pipeline, surge tank, penstock, and afterbay dam, would cost about $720,000. Total capital cost of power facilities would therefore be about $1,536,000. Total annual costs of $190,000 would include $9U,000 for capital recovery with interest at k percent, replacement, insurance, and general expense; $68,000 for operation and maintenance; and $28,000 for taxes foregone. -57- Economic Justification The foregoing analyses show that the estimated average annual power benefit is $114.6,200 per year while the estimated average annual cost of producing power is $190,000. Costs therefore exceed benefits and the purpose is not economically justified. Unevaluated factors which would further increase costs and reduce benefits are: (1) the allocation of any costs of reservoir storage capacity for hydroelectric power generation, and (2) annual reservoir drawdown, which would deter recreation use and reduce recreation benefits. The generation of power at Box Canyon Reservoir is not economically justified under present economic conditions, therefore, and should not be included as a purpose in formulation of the Box Canyon Project # Irrigation Two potential irrigation water service areas which might utilize water that could be conserved by the Box Canyon Project were located and studied. These two areas are: (l) the local lands along Wagon Creek, and (2) the southernmost portion of Shasta Valley near Edgewood. These areas are shown on Plate 1. Studies were made of the present and future irrigation demands that would occur in these service areas and of the water supplies available to meet such demands. Where demands were shown to exist, engineering and economic studies were made to determine whether the inclusion of water conservation for irrigation supplies in the Box Canyon Project would be economically justified. Wagon Creek Valley Studies of irrigation water supplies in Wagon Creek Valley were restricted primarily to an analysis of present and future demand for water. I -58- Water Reqiiirements . Almost all of the presently irrigated land in Wagon Creek Valley is devoted to pasture such as that pictured in Illustration $. Snail amounts of alfalfa, some small orchards and vegetable gardens make up the remainder of the irrigated lands. In the Department of Water Resources' Bulletin No. 58, "Northeastern Counties Investigation," the extent of land presently irrigated in Wagon Creek Valley was estimated to be 2,770 acres. Consumptive use of water by vegetation of the type in Wagon Creek Valley is about 2 acre-feet per year. Therefore, the present total consumptive use for the area is about 5>500 acre-feet per year. Because the service area is upstream from the proposed reservoir, consumptive use of water was assumed to represent the water requirement. • i-i' 'Tisiife?"? Irrigated Pasture in Wagon Creek Valley Approximately l,UhO additional acres in Wagon Creek Valley are classified as potentially irrigable, as shown on Plate 1. Most of this land lies au^ound the perimeter of land presently under irrigation. More shallow soil depths and rolling to hilly topography make this undeveloped land less desirable for irrigation, but in general it would be satisfactory for pastxjre and hay crops. It was assumed that this land would be cleared of trees and brush and brought under irrigation during the life of the project. Assuming the same consumptive use of water for this acreage as for presently irrigated acreage, the irrigation water requirement for this area would be about 3,000 acre-feet per year. The total maximum consumptive irrigation requirements of both present and future irrigable lands in Wagon Creek Valley were estimated to be about 8, $00 acre-feet per year. Water Supply . The present supply of irrigation water for lands along Wagon Creek is diverted directly from the stream by holders of riparian and appropriative water rights. Only in dry years is there presently a deficiency of irrigation water in Wagon Creek Valley, and then only at a few diversion points upstream from the confluence of Wagon and Spring Creeks. Field inspection during this investigation and information obtained from well owners and drillers in the Wagon Creek area indicate that ground water may be pumped from depths of 20 to UO feet. TMs ground water basin appears to be relatively constant and should furnish enough water to meet adequately that portion of the estimated majcimum irrigation demand over and above that met by Wagon Creek. The Box Canyon Reservoir site is located downstream from the irrigable lands in Wagon Creek Valley. The maximum water surface elevation in the proposed reservoir would be from 100 to hOO feet lower in elevation than the irrigable lands. The cost of water pumped from the reservoir would be greatly in excess of the cost of pumping from the underlying ground water basin, -60- Therefore, additional requirements for irrigation water in Wagon Creek Valley probably would be supplied by further development of Wagon Creek waters and by pumping from the ground water basin. Because no demand is anticipated for water from a reservoir at Box Canyon to irrigate Wagon Creek Valley, this purpose was not included in the formulation of the Box Canyon Project. Export to Shasta Valley The Shasta River watershed is separated from the Sacramento River watershed by a ridge which connects Mt. Eddy and Mt. Shasta. Shasta Valley contains extensive areas of irrigable land for which no water supply is available. Production on many areas presently irrigated is curtailed because of inadequate local water supplies. Importation of water from other sources is needed for maximum development in Shasta Valley, One Shasta Valley rancher presently is exporting water northward from the Morth Fork of the Sacramento River for use on irrigated pasture lands in the Shasta River watershed. The possibility of developing additional water for export from the Sacramento River watershed to Shasta Valley was studied in the Mt. Shasta City-Dunsmuir Area Investigation, Two plans were considered under the assumption that all water available from this source could be beneficially used in Shasta Valley, Water Requirements , The present agricultural economy of Shasta Valley is based upon livestock and the growth of feed for livestock, but small acreages of field and truck crops, including seed crops, have been planted. Water required for irrigation of these crops currently is supplied by several water service agencies from the Shasta and Little Shasta Rivers, With the exception of occasional dry years, the present supply of irrigation water in Shasta Valley is considered equal to the present requirements. The proximity -61- of the Shasta Valley area to the Sacramento River watershed and the possibility of developing a gravity flow transfer system similar to the existing Yreka Ditch makes the southern Shasta Valley area the logical service area for water exported from the Sacramento River. In the Department of Water Resources' Bulletin No, 83, "Klamath River Basin Investigation", maximum water requirements of the valley were estimated to be 381,000 acre-feet per year. The bulletin stated that even with maximum development of local water supplies in Shasta Valley, about 270,000 acre-feet would have to be imported from areas such as the Klamath and Sacramento Rivers to supply the ultimate needs. Lands lying at the southern end of Shasta Valley in the Eddy, Parks, suid Willow Creeks area shown on Plate 1 wo\ild have an estimated maximum supplemental requirement of approximately 138,000 acre-feet per year, according to the bulletin. Water Supply . The two methods for supplying irrigation water to Shasta Valley from the Upper Sacramento River watershed are: (l) the Tributary Diversion Plan to divert water from the streams tributary to the Sacramento River above Box Canyon damsite and to convey this water around the ridge into Shasta Valley, and (2) the Box Canyon Reservoir Diversion Plan to pump water directly from a reservoir at Box Canyon into a similar conveyance system to flow by gravity into Shasta Valley. Appraisal of estimated streamflow records of the Sacramento River near Mt. Shasta (I9IO-I96O) shows that the average flow for the months of February through May exceeds 20,000 acre-feet per month. This four-month period was chosen as the period during which unregulated flow could be diverted from the South, Middle, and North Forks of the Sacramento River and from Deer Creek to be stored in a reservoir at Deetz on Wagon Creek. The following major works would comprise the Tributary Diversion Plan: o Diversion structures on four of the tributaries listed in Table 14, would allow diversion of excess winter streamflows, but would not interfere with normal sximmer flows. -62- o The conveyance system of concrete-lined canals and fliimes, ranging in capacity from 75 to 175 second-feet, would convey water from the initial diversion point at elevation 3,900 feet on the South Fork Sacramento River to cin offstream storage reservoir at a point about 19 miles northward. Water would be collected enroute from the other three diversion structures. o A dam about 50 feet high and 3,000 feet long, containing 685,000 cubic yards of material, would be required at Deetz on V/agon Creek to form an offstream storage reservoir with sufficient capacity to store, for further diversion as needed during the irrigation season, the total annual winter diversion of approximately 30,000 acre-feet. o A pumping plant would lift water from the offstream storage reservoir into a canal about 200 feet higher than the reservoir. o A canal at approximately 4,000 feet elevation would convey water pumped from the reservoir northward about 11 miles to discharge through a powerplant into the Shasta River. The water would then be distributed for irrigation. ° A powerplant located at the terminal end of the canal (Section 17, TIN, R5W, M.D.B.(S^. ) could take advantage of a power drop of approximately 400 feet. This drop would generate energy equal to that required initially to lift the water into the canal, even allowing for transmission losses and the efficiencies of the pumping plant and powerplant. Under the Tributary Diversion Plan, head losses in the conveyance system would require initial diversion on the South Fork at an approximate elevation of 3,900 feet. This elevation would limit the contributing drainage areas of the combined tributaries to a total of about 47 square miles. Table 14 shows the area of drainage basins above the several proposed diversion points. Flows from each tributary which would be exceeded 30 percent of the time during the four-month diversion period also are shown in Table 14. Estimates of these flows were computed from flow measurements by stream gages operated near the diversion sites during the period July I960 through December I960 and from estimated historical flows of the Sacramento River near Mt, Shasta. If facilities were provided to divert excess winter flows from each tributary, the average annual water supply available to Shasta Valley would be about 30,000 acre-feet. As previously shown, the estimated future impaired runoff of the Sacramento River at the Box Canyon site is 192,000 acre-feet per year. The diversion of -63- FIGURE 5 SHASTA VALLEY IRRIGATION WATER DELIVERY PLANS -64- 30,000 acre-feet per year would leave an adequate supply for a reservoir at Box Canyon with the storage capacity of 30,000 acre-feet or greater. As an alternative to the Tributary Diversion Plan, the Box Canyon Reservoir Diversion Plan considers pumping water directly from Box Canyon Reservoir into the conveyance system. For the purpose of comparing the two plans, the amount of the diversion was assumed to be the same for both. The engineering features of the two diversion plans would be essentially the same except that the diversion structures needed for the Tributary Diversion Plan would be omitted and the pumping plant from Box Canyon Reservoir to the canal would be added. The following major works would comprise the Box Canyon Reservoir Diversion Plan: ° A pumping plant at Box Canyon Reservoir would lift water through approximately 4j000 feet of pipeline from an average water surface elevation of 3,150 feet at the reservoir into the conveyance system at elevation 3,840 feet. o A conveyance system similar to that proposed for the Tributary Diversion Plan would begin at elevation 3,840 and end 8 miles northwest at the off stream storage reservoir. o The offstream storage reservoir, pumping plant, canal, and powerplant would be similar to those proposed for the Tributary Diversion Plan, but would vary in size and requirements depending upon whether the plan was operated so that water f xx)m Box Canyon Reservoir would be pumped continuously or only during the irrigation season. Figure 5 shows the locations of the structures required in both diversion plans. Economic Justification . The proper determination of economic justification requires that the estimated benefits be compared to all costs of adding the purpose to the project. In this analysis, benefits were estimated for the assumed delivery of 30,000 acre-feet to Shasta Valley, but costs were estimated for only portions of the required diversion systems. -65- The cost estimates were discontinued when it became evident that the costs would exceed the benefits. The determination of the agricultural benefits is presented in the following section. Also presented is the cost estimate for a portion of each diversion plan. (1) Benefits . Estimates of agricultural benefits were based on the results of economic studies made for Bulletin No. 8? "Shasta Valley Investigation." Data relating to crop patterns, crop yields, costs of farm production, and crop prices for the vicinity of Grenada were assumed to be applicable to the southern portion of Shasta Valley. The use of payment capacity for water as a measure of agricultural benefits would result in the most liberal estimate of benefits if the newly developed water were applied to undeveloped land or lands having very low net farm income under present conditions. Values of estimated payment capacities under future conditions of crop pattern are presented in Table 15. Table 15 also shows estimated benefits from an average annual irrigation water delivery of 30,000 acre-feet to Shasta Valley. The 1970 present v;orth value of total benefits was estimated to be $3,086,000, assuming interest at four percent and a repayment period of 50 years, (2) Costs . The construction costs of the diversion structures - or pumping plant - and the conveyance system for both the Tributary Diversion Plcin and the Box Canyon Reservoir Diversion Plan were estimated from the initial point of diversion to the proposed offstream storage resei-voir at Deetz, The cost of diverting - or pumping - and conveying the water to the offstream storage reservoir was found to exceed the benefits in both plans. Under the Tributary Diversion Plan, the costs of constructing diversion structures in four tributaries and approximately 19 miles of canal and flumes leading from the initial diversion on the South Fork of the Sacramento River to the offstream storage reservoir were estimated to be -66- TABLE IL WATER SUPPLY AVAILABLE FOR TRIBUTARY DIVERSION PLAN Stream Sacramento River South Fork Middle Fork North Fork Deer Creek Wagon Greek TOTALS Drainage area above diversion sites,!/ in square miles 21.7 12.2 7.1 2.4 46.7 : Flows exceeded 30% :of time during diver- :sion period^/, in second-feet 75 45 25 10 12 167 1/ Figure 5 shows location of diversion sites. 2/ Diversion period is February through May. TABLE 15 IRRIGATION di^I^liFIT IN .3HA3TA VALL'^]Y '.VITH DIVERSION OF 30,000 ACRE-FniET i EU YHj^R FROM SACRAl^Oin^TO RIVER BASIN Weighted average paynient capacity, in dollars Irrigation benefit, 2/ Year Decade per acre -foot 1/ in dollars In first vear :Average for Total for : of decade : decade decade : Present worth 1970 3.55 1970-1979 3.83 1,149,000 944,000 1980 4.10 1980-1989 4.55 1,365,000 780,000 1990 5.CC 1990-1999 5.33 1,599,000 580,000 2000 5.65 2000-2009 5.90 1,770,000 449,000 2010 6,15 2010-2019 6.48 1,944,000 333,000 2020 6.80 Total pi "esent worth o f irrigation t benefit in 1970 = = 3,086,000 1/ Assuming that additional water will change crop pattern and increase payment payment capacity equals new net farm income, or irrigation -67- capacity. 2/ Assuming that benefit. $2,U00,000. The cost of the 50-foot high dam at Deetz was estimated to be $1,750,000, Ti;e quoted costs include 15 percent for engineering and 15 percent for contin;;encies, but do not include the co/isLderable additional cost of land acquisition and relocation of facilities. Tne auoLed costs alone, however, amoiant to :yl4,150,000, wliile the estiiuated benefit from water delivered to Shasta Valley during the 50-year repayment period would be only ^3*086,000. No estimates of cost for the remainder of L.ie required facilities for the Tributary Diversion Plan were made after the costs of tfie dam and diversion structures were determined to be in excess of the oenefits. Initial cost estimates for the Box Canyon Reservoir Diversion Plan shovied that the punipinf^ plant and pipeline alone would cost about $900,000, The cost per acre-foot of viater delivered through only this portion of the system was foand to be about #10 per acre-foot. The estimated average payment capacity in Shasta Valley during the 50-year repayment period, however, would be only iJ5»20 per acre-foot. Even the estimated maximum payment capacity reached in the year 2020 would be only |6,U8 per acre-foot. Because the cost of water delivered through only this portion of the system would be greater per acre-foot than the payment capacity in Shasta Valley, no cost estimates were made for the remainder of the works in the Box Canyon Reservoir Diversion Plan, Conclusions Studies during this investigation indicate that demand for water for irrigation of lands along Wagon Creek can be more economically provided from ground water and tributary sources than from Box Canyon Reservoir. Investigation also shows that transportation of irrigation water from the Sacramento River watershed into Shasta Valley is not economically justified by either the Tributary Diversion Plan or the Box Canyon Reservoir Diversion Plan because the cost of the diversion and conveyance works would be much greater than the possible benefits, -68- Therefore, it was concluded that conservation of water for the purpose of irrigation should not be included as a purpose in formulation of the Box Canyon Project. Municipal and Industrial Uses Consideration was given to the possibility of including the development of water supplies for municipal and industrial uses as a purpose in the proposed Box Canyon Project. This was done by estimating present and possible future demands for municipal and industrial water and determining whether these could be most economically met by the proposed project or by alternative sources. Water Requirements Estimates of use of municipal and industrial water under present conditions and water requirements for these uses under future anticipated conditions are discussed in the following sections. Potential Service Areas . Potential areas for municipal and indus- trial water service from Box Canyon Reservoir would be the towns of Mt. Shasta City and Dunsrauir and their surrounding areas. The development of homes, motels, restaurants, and commercicil establishments along the 6-mile portion of U. S. Highway 99 between Dunsmuir and Mt. Shasta City is beginning at the present time, and probably will continue in the future. No large water using industries are located within this area although existing industries such as saw mills, beverage bottling plants, and the rail yards at Dunsmuir use moderate amounts of water. Use of water by the Southern Pacific Railroad has been reduced significantly by the conversion from steam to diesel equipment. According to local officials, whose comments have been supported by studies made during this investigation, water using industries have shown little interest in locating in this area. Therefore, the percentage -69- of industrial water use, as reflected in the present water consumption data, is assvimed to remain about the same in the future. The United States Census of I960 reported that the population of Mt, Shasta City and surrounding area was 3,400 and that of Dunsmuir and surrounding area was 3,650. According to Department of Water Resources population projections for Siskiyou County, the estimated population of Mt. Shasta City would be 16,700 and that of Dunsmuir, 10,000, by the year 2020. The availability of developable land in the vicinity of Dimsmuir is expected to limit its future population. Present Water Use . Mt. Shasta City presently obtains its municipal water supply through a city-owned system that makes use of springs located about 2 miles east of the town on the slopes of Mt. Shasta, No records of delivery are available for this system because the system is not metered. However, records for diversion near the springs were available for 1959 and i960. The present average daily per capita use of water in Mt. Shasta City was estimated from municipal water use data from other towns in Northern California. The Northeastern Coimties Investigation (Bulletin No. 58, I960) reported that municipal water use of towns in moiintainous areas is about I60 gallons per capita per day. Because the Mt. Shasta City system is not metered, use of the system was assumed to be somewhat greater than average, or about 200 gallons per capita per day. Total annual use of the approximately 2,000 persons served by the system was estimated to be about lAO million gallons, or 430 acre-feet. The remaining poptilation is served by individual wells or springs. Approximately 90 percent of the Dunsmuir population is supplied with water by the Dunsmuir Water Corporation, a private enterprise. Springs supplying this system are located in the Sacramento River Canyon about 2 miles upstream from Dunsmuir, The water system is metered and annual use figures were made available for this study. The average daily per capita water use rate for this -70 service was calculated from records of water sold and the population served. The average rate of water use is about 130 gallons per day per capita. If this rate is applied to the 3,200 estimated population served by all indivi- duals and water agencies in Dunsmuir, the present annual water use in Dunsmuir is about 150 million gallons, or about 46O acre-feet. Future Water Requirements . Municipal and industrial water require- ments for both Mt. Shasta City and Dunsm\iir in the year 2020 were estimated on the basis of expected per capita use rates and population projections for that date. The average daily per capita water use for urban mountainous areas in 2020 is estimated to be 250 gallons per day. This rate was used for Mt. Shasta City, but was reduced to 200 gallons per day per capita for Dunsmiiir. With these rates of use and projected populations, the annual municipal and industrial water demand in Dunsmuir and Mt. Shasta City in 2020 is estimated to be 730 and 1,520 million gallons, respectively. These values represent about 2,300, and A, 600 acre-feet per year, respectively. A sxommary of estimated present and future municipal and industrial water requirements is presented in Table 16. Present Water Supply Municipal and industrial water for both Mt. Shasta City and Dunsmuir is supplied from springs by gravity flow while water for outlying areas is pumped from ground water. These sources provide an adequate supply of municipal water in both Mt. Shasta City and Dunsmuir at the present time. Because the water supply is derived from continually flowing springs, water is wasted during times of low water use. On the other hand, during times of high water use the supply from springs in Mt. Shasta is not sufficient and a well drilled in 1957 is used to augment the supply. However, the potential yield of this veil, indicated by pumping tests, is only partially utilized. The average annual production of the developed springs at Mt. Shasta City is estimated to be 215 million gallons and those serving Dunsmuir 200 -71- rH 5 c O r-i 9 % O Oi x> Q) -P -P (0 i +j «) ^ tn flj -H C «J u -P O X( a> •H •> H a. P, Q> rt •H O C -P t3 , U C as (D O, O X) O. as '. H to a (D bO Q c o •H -% to ^1 Q) -P > >» 0) -H O -^ (D (0 as C 15 0) o. W o as a. 8 8 vO o CM (d -p (0 x: CO ^ O CM 8 8 C\J o 3 O 3 H r-i ^ 8 rH § 8 CM •H O f^ u C o •H ■P (d (4 • S. to ^H 0) O •H fl -P •H fH § a> -p cd ^ 3: O O u ^ •d ce rH (0 a to «H tM o O n 0) bO ^ CO o ^ o (U 0) > V. m fi H 2 (h «H Cm TJ % -P -P Firm yield is the ma:d.mum sustained rate of draft from a reservoir that could be maintained through a critically deficient water supply period to meet a given demand for water. -75- Shasta Reservoir would be retained in Box Canyon Reservoir throughout the recreation season but would be released each fall into Shasta Reservoi-r. This wo\ild create additional evaporation amounting to about 5*000 acre-feet over a seven-year period, which would be replaced by water held in Box Canyon Reservoir at the time of the conservation release. Benefits Completion of Box Csinyon Reservoir by 1970 was assumed to increase the firm annual yield of the Delta by 2,900 acre- feet per year. No need for this amount would exist until at least 1982, because, according to the department's water demand and supply schedule, Oroville Reservoir, San Luis Reservoir, and the Delta Water Project will provide a surplus of water until that date. In about 1982 and subsequent years, water imported from the North Coast is scheduled to meet the next increment of demand and water from Box Canyon Reservoir logically might be fitted into the schedule. The benefits accruing to the Box Canyon Project over the 50-year repayment period were estimated to be $1,14.23,000 using a unit annual benefit of $U0 per acre-foot. The latter value is currently (1962) being used in evaluation studies of the State Water Facilities, and is applicable to analyses of future projects which may develop water supplies for export from the Delta Pool. Effect on Recreation Operation A reasonable assumption resulting from the operation study is that water stored in Box Canyon Reservoir would have been used in 1928-29, the first year of the critical period, because Shasta Reservoir would have reached a low storage of 1,100,000 acre-feet on September 30 of that year. Box Canyon Reservoir could have been refilled with winter runoff during the following six years by "borrowing" water that would otherwise be stored in Shasta -76- Reservoir. Thus, a summer recreation pool could have been maintained during the critical period and reservoir recreation would not have been severely injured. At the same time reasonable winter fish maintenaJice flows could have been maintained. Each year of such a critical period, the entire 20,000 acre- feet of active storage would have to be released to Shasta Reservoir in the fall after the recreation season, during September, October or November, to replace water that would normally be stored in Shasta Reservoir. This annual fall release of 20,000 acre-feet would continue until Shasta Reservoir would spill again and new surplus water could be stored in Box Canyon Reservoir. Lowering the reservoir to its minimum pool level each year during the critical period would result in a loss in recreation visitor-days. Tlas loss was estimated to be the visitor-days attributable to fishing during the last hS days of the season. About U,500 visitor-days, on the average, would be lost during each of the seven years in which the release would be made. Assum- ing that the critical period would occur between the seventeenth and twenty-third years of project operation, the present worth of the loss in recreation benefits would be about $35,000. Extreme seasonal fluctuation of the reservoir between normal and minimum pool, however, would seriously curtail the fish populations making up the reservoir fishery wliich studies of recreation benefits assumed would be an essential part of the recreational attractiveness of Box Canyon Reservoir. Under such conditions of seasonal fluctuation, open season fishing co\ild be maintained only by planting trout of catchable size. It was assiomed the fishing and recreation attraction could be main- tained at the reservoir during the spring and summer, prior to the release of stored water, by an intensive fish planting program. The planting program would require about 225,000 catchable trout duilng the first year following the release of stored water. This number would increase throughout the seven-year -77- critical period and five years thereafter to 325,000. To estimate tlie cost of planting, it was assumed that the fish could be supplied by e:v^; ^ '"^ z.^^^. 0'<^ •as^^-'sr i:s2^^^^^ -*^-. -^^:i^ til:!* Box Canyon Deimsites (Looking Upstream) -83- This ability would vary because different water levels vrould affcet the size of water surface and beach areas, the length and slope of shorelines, the depth and temperatiu'e of water, and the extent of shallow aj'^eas to provide the proper environiuent for the production of fish food. Recreation studies showed that a i^eserv'oir with a './ater surface elevation of 3^200 feet would ci-cate the most desirable setting. The upper and lower sites were coriipared on the basis of a norraal pool at elevation 3^200 feet. Development of a reservoir to this water surface elevation by a dam at the lower site wd uld require about four times the volume of earth embankment required by a dara at the upper site, and therefore would necessitate a greater expenditure. A dam built to the same elevation at the lovrer site would create a reservoir of ^6,000 acre-foot of storage capacity, but at a greater cost. At elevation 3^200 feet, maximum storage capacity at the upper damsite would be about 35^000 acre -feet — well within storage require- | raents. Ihe upper damsite, therefore, was selected to provide the smallest facility possible in terms of cost and size to serve adequately the predicted recreation use of the reservoir. " It was determined that the optimum size of reservoir as disc^osscd above could be reduced to a normal pool elevation of 3^190 feet without a loss in either recreation attraction or benefit. This lower dam, which would effect a considerable saving in construction cost, would provide a reservoir with a , surface area of ^85 acres, a capacity of 30,000 acre-feet, and a shoreline of approximately 7 miles. In analyzing the size of reservoir needed to fulfill the water conservation purpose to develop additional yield to the State Water Facilities, it was found that the benefits accruing to this purpose would not justify construction of a reservoir larger than the minimxam size needed for recreation. -84- FolloiTlng geologic investigation, preliminary engineering designs Tor vai'io'as sizes or both zoned earthfill and concrete arch dams at the upper dajn- site showed tliat a zoned earthfill dan would be more economical than a concrete arch dam. Therefore, a zoned earthfill dara was selected as the more desirable for the Box Canyon Project. Geology of the Upper Uamsite During geologic exploration at the upper damsite, surface materials were mapped and classified, A seismic survey and a field permeability test were made, and eight holes, varying in depth from 6 to 06 feet, were bored with an auger drill. This exploration showed that volcanic rock forms the lower portion of both abutments. 'The volcanic rock is overlain by lake deposits and glacial drift on the left abutment and by red cla;?' materiauL of volcanic origin on the right ab^itment. Illustration 7 pictures both abutments. Possible leakage througti the sediments of the left abutment and through those sediments imderlying the volcanic rock creates the principal foundation problem. Prior to final planning and design of a dam at this site, it is recommended that the geology and foimdation conditions be thoroughly investigated by core drilling, water pressure testing, field permeability testing of abutment areas, and adequate construction materials drilling, sampling, and testing. Foundation conditions which particularly would affect a zoned earth- fill dam at the upper damsite are discussed under the headings: Right Abutment, Chaxinel, Left Abutment, and Spillway. Additional conditions which particularly would affect a concrete arch dam, had such been chosen for the Box Canyon Project, are discussed separately and more briefly. Right Abutment. The portion of the right abutment below elevation 3,150 feet is a cliff of volcanic rock, nearly vertical and at places over- hanging. Above this rock are deposits of a red clay material of volcanic -85- Upper Dajnsite (Looking Do-wnstream) -86- origin. Subsurface infonr.ation obtained irom sevei-al au^er holesi/was used to locate the contact between the rock and the red clay material. Above elevation 3^150^ the slope of the rock flattens aui-uptly to about 10 degrees, continues to rise beneath the soil cover to about elevation 3^190^ and thereafter begins to fall away. Auguer hole B-A8, about 250 feet from the riia - of the canyon, shows that the firm rock surface has dropped back to about elevation 3,150. Plate 5, "Geologic Sections and Auger Hole Logs," presents a cross section of the damsite showing this contact. Vertical joints both perpendicular and parallel to the stream channel , divide the rock of the right abutment into coliLiUiar blocks several feet or more across. These joints are open, have small flows of water coming from them, and ai-e believed to be filled ■'./•ith clay. The joints ai'c closed in the cliannel and may close with depth in the abutment. Clay filled joints present no structural problems for an eai-thfill dam, although some grouting of joints in the abutment may be necessary to prevent leakage. A good location for a fill dam is shoim on Plate h as line A-A' . Special compaction procedures would be necessary to assui'e a water-tight contact between the imperviotis core and the steep lower portion of the right abutment. Stripping for an eai-thflll dam would vary between zero to 15 feet on the upper portion of the right abutment and shaping of hard, irregular rock would be required on the lower portion of the abutment. Channel Section. At the upper damsite, the channel is about 70 feet wide and is bounded by neai'ly vertical to overhanging I'ock cliffs. Hard rock outcrops are present in the channel, sometimes covered by small discontinuous accumulations of gravel and talus. Very little foundation preparation would be required beyond removal of the gravel and talus, and the shaping of the bedrock. 1/ The locations of the holes, E-A8 throijgh B-A12, are sho\m on Plates k and 5. -87- Left Abutment . Topographically, the left abutment, much lower than the right, wovild limit an earthfill dam to elevation 3,220 feet. The left abutment is composed of volcanic rock as described for the right abutment and overlain by glacial drift and lake deposits. The contact with volcanic rock begins at about elevation 3,l50 and is shown on Plate 5, Section A-A'. The average slope of the left abutment is less than that of the right abutment. Slope of the volcanic rock varies from vertical to kS degrees; that of the glacial drift overlying the rock averages about 25 degrees. Two auger holes, B-AU and B-A5, were drilled in the glacial drift. A field permeability test was run on hole B-AU. The field permeability test indicated a permeability of about 5 feet per day. Samples were taken from both holes for the purpose of laboratory permeability tests of remolded samples. The tests showed that the glacial drift material is quite pervious in the natural state and that some treatment of this material mi^t be required to prevent reservoir leakage and possible failure of the left abutment. Spillway . Spillways at various elevations through both the right and left abutments were considered and a site on the right abutment was chosen. A spillway on the right abutment would be cut throu^ the red clay material and could be founded on the solid volcanic rock at elevations below 3,175 feet. Such a solid foundation is preferable for a spillway. On the left abutment, the spillway cut would be entirely in glacial drift material at elevations above 3>l60 feet. Concrete lining of the spillway would be necessary to prevent erosion damage to the spillway channel on either abutment. Concrete Arch Dam . The upper site would provide a good location for a concrete arch dam slightly upstream from that selected for an earthfill darasite. Foundation conditions along the left and right abutments and the channel section are the same as at the proposed location of the earthfill dam. Weathering, -88- topography, and jointing are important factors which would affect a concrete arch dam. Deep weathering of the volcanic rock was indicated by the low seismic velocities along line F shown on Plate U. Section C-C, Plate 5, shows a geologic cross section of the concrete arch damsite. Although the slope of the rock drops off rapidly above elevation 3>135 on the left abutment, an artificial concrete abutment could be provided for a dam with its crest at elevation 3,l60. To construct a higher dam, topography of the right abutment would also require addition of an expensive artificial abutment. Furthermore, the jointing which is present in both abutments presents a very serious problem and casts doubt on the ability of the foundation to support an arch structure. The first step toward effective grouting of these joints — washing out the clay which may fill them — may be very difficult to accomplish. Proper evaluation of the problem of preparing the foundation for a concrete arch dam would require further exploration of the jointing. Construction Materials A svifficient quantity of material required for a zoned earthfill dam is available within 2 miles of the damsite. Two general types of material, pervious and impervious, are required for construction of a zoned earthfill dam. Pervious material through which water will pass freely provides drainage and stability to the structure; whereas impervious material \*iich restricts the passage of water is used as a core in the dam to prevent excessive leakage, Pei^ous Material , Materials satisfactory for the pervious sections of the dam are available from three sources. These ares °Streambed gravels deposited immediately upstream from the damsite in the reservoir area. °Granitic rock which outcrops on the south side of Ney Springs Creek, Volcanic rock which outcrops on the north side of Ney Springs Creek, -89- The locations of these sources are shown on Plate 6, "Location of Construction Materials," as B3, Q2, and Ql, respectively. Q\;ality of the three materials as indicated by laboratory tests of soundness, specific gravity, and absorption was found to be nearly eqvial. The streambed gravels were chosen for the pervious sections of the dam because of their proximity to the damsite and their ease of excavation. These factors would result in lower construction costs than wo\ild occur were use made of either of the alternative borrow sites. It is estimated that there are over 2,000,000 cubic yards of streambed gravels available. Concrete Aggregate . Possible sources of concrete aggregate would be the same as those for the pervious material. However, sufficient tests to determine the suitability of these sources for concrete aggregate were not performed during this investigation. Impervious Material . Laboratory tests were conducted on two sources of impeirvious borrow material overlying the volcanic rock of the abutments. These sovirces are the glacial drift material of the left abutment, and the red clay material of the right abutment. Tests of the glacial drift material from the left abutment indicated permeability rates ranging from 5 feet per day for material in the natxiral state to 0.032 feet per day for samples compacted by application of 20,000 foot-pounds per cubic foot. No permeability tests were performed on the red clay material from the right abutment, but the permeability rate certainly would be much lower than that for the left abutment material. Tests indicate both materials would be sxiitable for the in^jervious core if proper coorpaction methods were utilized. Properties of each material are presented in Table 17. -90- TABLE 17 PROPERTIES OF IMPERVIOUS MATERIAL Material Plasticity index Specific gravity Angle of internal friction Left abutment, glacial drift Right abutment, red clay 15 26 2.67 2.80 35' 20^ Because the steep abutments could cause differential settlement, the more plastic, clay material from the right abutment, was chosen as the core material. Box Canyon Project The three main elements of the Box Canyon Project, form\ilated either as a single-purpose or a multipurpose project, are: (1) the dam and appurtenant structures, (2) the reservoir, and (3) the recreation facilities. The dam and appurtenant structures were designed, in accordance with standaixi engineering principles, to satisfy the recreation purposes of the project by use of the most economical combination of embankment, spillway, and outlet works. Founda- tion conditions received adeqixate consideration for planning cost estimates. Thie dam was designed to be constr^icted of available natural materials and the spillway, to pass the probable maximum flood without damage to the dam. Recreation facilities were designed to meet standards established by the Department of Water Resources and the Department of Parks and Recreation, * This is the flood discharge that may be expected from the most severe combination of critical me teoro logic and hydrologic conditions that are reasonably possible in the drainage basin. -91- The features of the Box Canyon Project reasonably represent those which would be selected for construction to meet the intended purposes of the project. Further exploration of foundation conditions at the damsite, more extensive tests of borrow material, and more thorough design analyses would be necessary before actual construction. Although such further study might result in some changes in design, the estimated costs of the project are believed adequate for comparison with the estimated benefits accruing to the project. Such comparison is necessary to the evaluation of the economic justification of the project. Capital costs of the project would include the costs of acquiring the dam and reservoir sites, of constructing the dam arxi appurtenances, of acquiring the necessary recreation areas and constructing recreation facilities, and of relocating all public utilities. Estimates of coital costs are based on unit prices that prevailed in October 1961, and allow 1$ percent for construction contingencies, 15 percent for engineering and administration, and U percent a year for interest during construction. Annual costs include costs of operation, maintenance, replacement, and general expense, interest at h percent a year on the capital investment, and repa;y'ment throughout 50 years at k percent interest. Dam and Appurtenant Structures The zoned earthfill dam selected to fulfill requirements of the project and its site would rise 220 feet above streambed to a crest at elevation 3,215 feet above mean sea level and would contain 680,000 cubic yards of fill material. The same features of the dam and spillway would be used for either the multipurpose or single-purpose project. The multipurpose project would require a larger outlet system. Pertinent features of the dam and reservoir -92- are given in Table l8. Table 19 itemizes costs Msed to estimate total costs of the dam, reservoir, and appurtenant stnictiires required for a single-purpose recreation project; and Table 20 itemizes these costs for the multipurpose project. Embankment . The embankment section would contain a moderately thick impervious core of red clay material obtained from the spillway excavation and from a borrow area adjacent to the right abutment. The impervious core would be flanked on each side by transition zones constructed of selected glacial drift material from sources in the reservoir area adjacent to the left abutment. Overlying the transition zone would be a pervious embankment zone of natural sand, gravel, and cobbles. Sufficient quantity of this material is present in the reservoir area immediately upstream from the dam. Plate 7, "Box Canyon Dam: General Plan and Sections," shows slopes and positions of the various zones within the embankment section. The steepness of the canyon walls at the damsite would necessitate severe shaping of the abutments under the core and transition zones to reduce the danger of transverse cracking within the zones. The red clay used in the core would further reduce danger of cracking because of its plastic qualities. Extensive testing and exploration to determine leakage and stability characteristics of the left abutment under sustained water loads will be necessary before proper treatment of this abutment can be designed. However, for the purpose of this report, an impervious blanket was assiuned to be required over an area extending from the dam approximately 1,$00 feet up Wagon Creek and from the Wagon Creek streambed up to elevation 3»200 feet. The problem area is delineated on Plate 7. The ai^ea has a natural average slope of less than 2:1, Prior to blanketing, this slope would be stabilized to prevent possible sloughing under long term saturation. Stabilization would require that the slope be flattened to 3sl« Details of the slope treatment are also presented on Plate 7« -93- TABLE 18 FEATURES OF BOX CAI^ON DAM AND RESERVOIR Dam and Reservoir Location SE i. Section 29, TUON, RliW, MDB&M Stream Sacramento River Reservoir Drainage area in sqiiare miles 122 Elevation, in feet USGS datum Maximum water surface 3,210 Normal water surface 3,190 Minimum pool 3,100 .. Storage capacity at normal water surface, in acre-feet 30,000 Reservoir area at normal water surface, in acres . . U85 Dam Structure Type Zoned earthfill Crest elevation, in feet USGS datum 3,2l5 Streambed elevation, in feet USGS datum 2,995 Height of dam above streambed, in feet 220 Crest length, in feet 1,250 Crest width, in feet 30 Slopes Upstream face, above berm at elevation 3,l50 . . 2:1 Upstream face, below berm at elevation 3,150 . . 2.5:1 Downstream face 2;1 Total embankment, in cubic yards 680,000 Spillway Type Ogee Crest elevation, in feet USGS datum 3,190 Crest length, in feet 125 Design flood surcharge head, in feet 20 Design flood residual freeboard, in feet . 5 Design capacity, in second-feet U3,000 Energy dissipator Flip bucket Outlet Works for Single-Purpose Project Type Cut and cover Diameter, in inches 36 Maximum discharge at normal pool, in second- feet . . 3l6 High pressure slide gate, dimensions in feet .... 3.5 x 3«5 Regulating valve size, in inches 30 Outlet Works for Multipurpose Project Type Cut and cover Diameter, in inches U2 Maximum discharge at normal pool, in second-feet . . 365 High pressure slide gate, dimensions in feet .... U»0 x U.O Regulating valve size, in inches 36 -9U- TABLE 19 SINGLE-PURPOSE PROJECT ESTIMATED COST OF BOX CANYON DAM AND RESERVOIR (Based on prices prevailing in 1961) Dam crest elevation: 3>2l5 feet, USGS datura Spillway crest elevation: 3,190 feet, USGS datum Height of dam crest above streambed: 220 feet Item Unit t Quantity t Unit price Total cost Dam Diversion and care of stream lump sum $ 22,000 Excavation, foundation strip- ping and core trench above elevation 3,l50 ft. cu yd 31,600 $ .75 23,700 Excavation, rock; abutment shaping cu yd 2U,300 6.00 1U5,800 Drilling and grouting lin ft 6,000 10.00 60,000 Stripping impervious borrow pit cu yd 75,000 .35 26,300 Borrow excavation Impervious cu yd 97,500 .78 76,100 Pervious cu yd U01,700 .70 281,200 Transition cu yd 100,600 .78 78,500 Embankment Impervious — from borrow cu yd 78,000 .20 15,600 Impervious — from spillway Seilvage cu yd 83,000 .25 20,800 Pervious cu yd U01,700 .10 U0,200 Transition cu yd 77,U00 .20 15,500 Rock from spillway salvage cu yd ho, 000 .50 20,000 Special compaction cu yd 5,900 2.00 11,800 Impervious Blanket Site preparation lump sum 33,700 Bank stabilization Excavate and compact cu yd 17i;,800 .56 97,900 Impervious borrow cu yd 36,100 .7U 26,700 Impervious blanket cu yd 72,000 .7U 53,300 Slope protection cu yd 111,600 .76 8U,800 Riprap cu yd U,ooo 2.00 8,000 Spillway Excavation, common cu yd 110,000 1.17 128,700 Excavation, rock cu yd U8,ooo 2.50 120,000 Structural backfill cu yd 2,750 5.00 1U,000 Concrete weir and bucket cu yd 1,760 50.00 88,000 Concrete walls cu yd 1,950 80.00 156,000 Concrete chute floor cu yd 1,830 U5.00 82,LiOO Cement bbl 6,270 5.00 31,U00 Anchor bars — drill lin ft i,UUo 3.00 U,300 Reinforcing steel lb 503,000 .15 75,U00 Drains lin ft 3,300 U.50 1U,800 Bridge lump sum 56,000 $ 837,500 $ 3OU,U0O $ 771,000 -95- TABLE 19 SINGLE-PURPOSE PROJECT ESTIMATED COST OF BOX CANYON DAI1 AND RESERVOIR (Continued) Spillway capacity with 5-foot freeboards U3,000 second-feet Reservoir capacity at spillway crests 30,000 acre-feet : » : Unit : Total Item : Unit i Quantity : price : cost Outlet Works Excavation, rock cu yd 300 $ 5.00 $ 1,500 Concrete — conduit - cu yd 90k Uo.oo 36,200 Concrete — intake tower and valve house cu yd 30U 70.00 23,800 Cement bbl 1,72U 5.00 8,600 Reinforcing steel lb 175,600 .15 26,300 Steel pipe lb 98,UOO .50 U9,200 Steel trash rack lb U,8oo .50 2,1400 30-inch Howell Hunger type valve ea 1 20,000.00 20,000 3.5' X 3.5' H.P. slide gate ea 1 33,000.00 33,000 $ 201,00c Subtotal - $2, 113, 90c Engineering and administration Contingencies Interest during construction at U percent TOTAL COST OF DAM 317,100 365,000 112,000 $2,908,000 ac 380 $ 263.00 mi U.2 U5, 500.00 lump sura lump sum Reservoir Clearing to elevation 3,195 Road relocation Sewage plant relocation Land acquisition Engineering and administration Contingencies Acquisition contingencies Interest during construction at U percent TOTAL COST OF RESERVOIR TOTAL CAPITAL COST, DAM AND RESERVOIR, SINGLE- PURPOSE PROJECT 100,000 191,000 10,000 371;, 800 675,800 U5,200 51,900 75,000 33,900 $ 881,800 13,789,800 -96- TABLE 20 MULTIPURPOSE PROJECT ESTIMATED COST OF BOX CAI^IYON DAM AND RESERVOIR (Based on prices prevailing in 1961) Dam crest elevation: 3j2l5 feet, USGS datum Spillway crest elevation: 3>190 feet, USGS datum Height of dam crest above streambed: 220 feet Spillway capacity with 5-foot freeboard: U3>000 second-feet Reservoir capacity at spillway crest: 30,000 acre-feet Item : : : Unit : Unit t Quantity t price Total cost Dam (See Table 19) Subtotal $ 837,500 Impervious Blanket (See Table 19) Subtotal 30U,Uoo Spillway (See Table 19) Subtotal 771,000 Outlet Works Excavation, rock cu yd Uoo $ 5.00 $ 2,000 Concrete — conduit cu yd 1,03U Uo.oo ia,7oo Concrete — intake tower and valve house cu yd 359 70.00 25,100 Cement bbl 1,929 5.00 9,600 Reinforcing steel lb 198,000 .15 29,700 Steel pipe lb 102,830 .50 51, Uoo Steel trash rack lb 6,550 .50 3,300 36- inch Howell Bunger type valve ea 1 29, 000.00 29,000 U' X U' H.P. slide gate ea 1 U5, 000.00 ij-5,000 L 236,900 Subtotal $2,1U9,800 Engineering and administration 322,500 Contingencies 370,800 Interest during construction at U percent TOTAL COST OF DAM TOTAL COST OF RESERVOIR (See Table 19) TOTAL CAPITAL COST, DAM AND RESERVOIR, MULTIPURPOSE PROJECT 113,700 $2,957,000 881,800 $3,838,800 -97- Spillway . An uncontrolled spillway located in the nght abutment would consist of an unlined approach channel, a 125-foot long concrete ogee weir with the crest at elevation 3*190 and a 500- foot long, converging concrete- lined chute. A flip bucket at the end of the chute WDuld break the force of the water entering the stream channel. The spillway is designed for a maximum discharge of U3>000 second- feet with a surcharge of 20 feet to allow a residual freeboard of 5 feet on the dam. This maximum discharge capacity was determined from a flood routing study based on reservoir inflow from the maximum probable flood. No reduction in peak flow would be realized from surcharge storage during the maximum probable flood. Outlet Works, Single-Purpose Project . A cut and cover outlet works, consisting of an outlet structure, an intake struct\3re, and a 36-inch diameter steel-lined concrete conduit, 1,065 feet long, would be constructed in the stream channel. The conduit was designed to discharge 300 second-feet under a minimum head of 150 feet. The outlet works would be used for normal stream maintenance releases and also for diversion of the stream during construction of the dam. The intake structure, a reinforced concrete tower rising 28 feet above streambed, would provide for possible reservoir sedimentation. A hydraulically operated high pressure slide gate wovild be installed near the upstream end of the conduit to provide for emergency closure. An outlet regulating valve would be installed at the downstream end of the conduit to dissipate energy and to provide regulated stream releases. A 10-inch bypass line with necessary control equipment would be installed parallel to the main conduit to guarsintee a source of water for the downstream fishery in case of emergency closure of the main outlet works. A gated outlet through the base of the spillway weir would be provided to release up to 50 second-feet of water from the upper portion of the reservoir. -98- This vater would "be used for temperature control of the downstream fishery maintenance release. Outlet Works, I^ultipvirpose Project A cut and cover outlet works, consisting of an intake structure, a i4-2-inch steel-lined concrete conduit, 1,065 feet long, and an outlet structure would be constructed in the stream channel. The outlet works would be used for normal stream releases, release of water during the critical period to increase Delta yield, emd also for diversion of streamflow d\iring construction of the dam. The conduit was designed to discharge a total of 28,800 acre-feet of water from the reservoir during a period of 45 days under a head vajrying from 195 feet at the beginning of the period to 110 feet at the end of the period. The intake structvire, bypass line for emergency release of water for streamflow maintenance, and the outlet structure would remain the same as the smaller diameter outlet works estimated for the single-purpose recreation project. However, the emergency slide gate would be increased in size to k feet by k feet, and the outlet regulating valve would be 36 inches in diameter. Reservoir Land Acquisition A total area of 2,088 acres was considered as the minimum reservoir recreation project area to provide for the dam and reservoir and for lands for recreation facilities to meet the estimated water-associated recreation demands. This area, designated as the proposed recreation area on Plate 3> 'was used for the purpose of cost estimates presented herein to determine economic justifica- tion of the Box Canyon Project. However, it was determined in consultation with the Department of Parks and Recreation that an area surrounding the reservoir suitable for establishment as part of the State Park System wovild comprise about 4,800 acres. This larger area woxold fulfill state park standards by joining U. S. Forest Service lands to the south and west of the recreation project area and by including lands within the watershed along Rainbow Ridge to the north. -99- Lands proposed for acquisition for the reservoir recreation project area are discussed in the following paragraphs. Additional lands that would be desirable for a state park unit are discussed at the end of this chapter under the heading "State Park System Development." The area subject to inundation by Box Canyon Reseivoir includes two farms -vdaich contain approximately 300 acres of developed agricultxiral land. The balance of the inundated area Eind the other land included in the acquisition for recreation purposes and buffer zones is imdeveloped, cut-over timberland. This land includes 60 acres in Section 28, Township 40 North, Range 9 West, planned as the site for relocation of the Mt. Shasta City sewage oxidation ponds. The present sewage ponds lie at the site of the left abutment of the proposed Box Canyon Dam. The area designated for relocation of the oxidation ponds is shown on Plate 3« Of the lands proposed for acquisition, about 700 acres adjacent to the reservoir would be suitable for recreation development to fulfill the estimated water- associated recreation needs. Of this acreage, about 400 acres would be best suited for development of campsites and about 200 acres, for development of picnic areas. The remainder of the recreation area could be developed for beach areas, boat launching ramps, concession areas, overlook areas, and access roads. Areas best suited for these various types of recrea- tion development are delineated on Plate 3« The remainder of the acquired land, about 85O acres, would be neither inundated by the reservoir nor designated for recreation development and should be preserved as natural biiffer area and to provide public access to adjoining U. S. Forest Service lands. ; r.j,. Property descriptions and information on land ownership were supplied by the Siskiyou County Assessor. The value of each tract was determined by a market analysis method which compared the land with similar property which had been involved in recent sales during 1959 and- I960. The Siskiyou Coimty -100- Recorder and local real estate agencies supplied data on such sales of properties in or near the area involved. The cost of acqiiisition of the 2,088 acres is estimated to be $^+50,000 and includes severance damages, acquisition overhead costs, and contingencies. In the reservoir area, there are no public utilities which would reqiiire relocation. The estimated cost of constructing the new facilities required as a result of the assimed relocation of the Mt. Shasta City sewage oxidation ponds would be $10,000. The Mt. Shasta City dijnip is adjacent to the present sewage pond area and also would require relocation. Its cost of I relocation was considered minor and was not included as a project cost. The Mt. Shasta City-Castle Lake county road through the reservoir area and a private logging road presently parallel to the Sacramento River in the reservoir area would require relocation. The coimty road would be routed I out of the reservoir area by way of the dam crest. The logging road would be routed aroxind the south side of the reservoir and would be used for access to the recreation areas plaxmed for the south and east shores of the reservoir. I Plate 3 shows the planned locations of these two roads. The total cost of the k.2 miles requiring relocation would be an estimated $253^000. An all-weather, asphalt surface would be provided. Estimated costs of acquiring the necessary land for the Box Canyon Project and of relocating the sewage ponds and the two roads have been shown in Table 19. In addition to the 2,088 acres needed for the proposed recreation area, the Department of Fish and Game has recommended 100 acres be provided to replace intermediate deer range which would be inimdated by the reservoir. The loss of this range woiild be detrimental to the migratory deer herd, according to a study conducted by the Department of Fish and Game, to determine probable effects of Box Canyon Reservoir on the fish and wildlife Hancock Library of Biology -101- and Oceanography reGQurces of the Upper Sacreunento Kiver Basin. As selected for planning pui'poses, this 100-acre pai'cel would lie in the IW-i^ of Section 32, T'f-ON, Tlk-l-i, and wou.ld be adjacent to the project acquisition boiindeiry. Tlic cost of acquiring this land was estimated to be JJilO^OOO. Recreation Facilities Estimates of the extent of recreation facilities needed at Box Canyon Reaei-voir to meet the projected demand were made to ascertain that the site could be developed to meet demand and to estimate the cost of recreation facilities. Development of suitable facilities for camping, picnicking, boating, and swimming would be desirable in the areas delineated on Plate 3» Selection of these areas followed inspection of possible sites aJid consideration of their suitability in terms of use and development. Although a substantially different plan of development could result from the more detailed studies of the site and facilities which woiild be required prior to actual construction, the plan presented is believed to represent adequately the costs of development. Estimated demand for recreation facilities would require initial installation of 2^5 campsites, 50 picnic units, 1 beach area, a boat launching ramp, concession area, and an overlook area for sightseeing. In addition, a water supply would be developed, sanitary facilities installed, access roads constructed, and other items required for proper operation and maintenance of the recreation facilities would be provided. Estimated recreation demand in the year 2020 would require a total i of 870 camp imits, 300 picnic units and expansion of the water system, sanitary facilities, beach areas, and concession ai-eas. Table 9 (page ^5) presents a schedule of costs for installation of recreation facilities to standards used by the State Park System. The capital cost of the initial facilities was estimated to be '^968,000 and future installa- tions would require capital expenditures of $2,705,000 as shown in Table 9« -102- The total present worth of installation of recreation facilities is $1,990,000. The cost of operation, maintenance, and replacement of the initial recreation facilities was estimated to he $50,000 per year. This woiold increase to $20U,000 when all of the recreation facilities would be installed. The total present worth of operating, maintenance, and replacement over the 50-year period would be $2,117,000. The total present worth of operation and maintenance of the 100 acres of deer range recommended by the Department of Fish and Game is ^k6,000. The initial cost of improving this range is estimated to be $20,000. Summaiy of Project Costs The estimated costs of the Box Canyon Project as formulated for single- purpose and multipurpose projects are presented in Tables 21 and 22, respectively. Tlie costs of the project have been shown as initial and future expenditures. Initial expenditiJires represent the costs of construction required to build the project and put it into the first year of operation. Future costs, expressed in terms of present worth, are additional costs required during the 50-year economic life of the project, and include annual expense for operation, maintenance and replacement, and costs of installation of future recreation facilities. Tlie sum of initial and future expenditures represents total project costs that may be compared to total project benefits. The s ingle -pm-pose reci-eation project was estimated to have initial costs of ^ij-, 788, 000 and total project costs reduced to a 1970 present worth value of ?8,403,000. ihe average annual equivalent cost over the 50-year period with interest at k percent is $391^000. The multipurpose recreation and conservation project was estimated to have initial costs of $^1-, 837^000 and total project costs reduced to a 1970 present worth value of $8,72^,000. The average annual equivalent cost over the 50-year period -v^ith interest at k percent is $^06,00C. -103- TABLE 21 SUMMARY OF SINGLE-PURPOSE BOX CANYOJ PROJECT COSTS Item Capital Cost : Engineeidng, Construe- : administration, tion cost : contingencies & t interest during : construction P*resent worth of capital cost Average annual equivalent of present worth Initial Expenditures Dam and appurte- nances Reservoir Recreation facili- ties Replacement deer range Subtotal $2,llU,000 I 79U,000 676,000 206,000 968,000 * 30,000 ^ $3,788,000 $1,000,000 $2,908,000 $135, UOO 882,000 Ui,ioo 968,000 U5,ioo 30,000 ijUoo $U, 788, 000 $223,000 Future Expendittires Recreation facili- ties Operation, mainte- nance, replacement & general expense of dam Operation, mainte- nance & replacement of recreation facilities 2,705,000 1,022,000 U30,ooo-^ 2,117,00O«^> U7,600 20,000 98,500 Operation and mair nance of deer range ite- - U6,000«-"^ $3,615,000 $8,U03,000 2,100 Subtotal TOTAL $2,705,000 $6,U93,000 $1,000,000 $168,200 $391,200 * Included in construction cost **TotaJ. present worth of annual expenditures -10^1- TABLE 22 SUMMARY OF MULTIPURPOSE BOX CmJCM PROJECT COSTS t Capital Cost : Present worth ■ : Construe- s Engineering, : administration, : : Average annual Item ; : tion cost : contingencies & ; interest during : construction : of capital cost ' equivalent of ' present worth Initial Expenditures Dam and appurte- nances $2,1U9,000 $ 808,000 $2,957,000 $137,600 Reservoir 676,000 206,000 882,000 Ul,100 Recreation facili- ties 968,000 * 968,000 U5,ioo Replacement deer range 30,000 $3,823,000 •M- 30,000 $U, 837,000 i,Uoo Subtotal $i,oiU,ooo $225,200 Future Expenditures • Recreation facili- ties 2,705,000 * 1,022,000 U7,600 Operation, mainte- nance, replacement & general expense of dam Operation, mainte- nance & replacement of recreation facilities Operation and mainte- nance of deer range U30,000«* 2,117, 000«* U6,00O-* 20,000 98,500 2,100 Catchable trout ing program plant" w~» **•« Subtotal TOTAL $2,705,000 $6,528,000 $i,oiU,ooo 272,000 »» 12,700 $3,887,000 $180,900 $8,72U,000 $U06,100 * Included in construction cost •«-a-Total present worth of annual expenditures -105- Project Operation The operation schedule which would most benefit recreation at Box Canyon Reservoir would maintain a relatively constant pool elevation during the entire recreation season. A constant pool elevation during the entire year would also be beneficial to the reservoir fishery because of the additional production of fish food in shallow areas. However, the releases recommended by the Department of Fish and Game to maintain certain flows in the downstream fisheiy would cause some drawdown of the reservoir pool during dry seasons of most years. More severe drawdown would occur as the result of releases of stored water to fulfill the water conservation purpose to supply new yield to the State Water Facilities. Although these two requirements for project water — maintenance of constant pool in the reservoir and releases for either maintenance of flow in the downstream fishery or for water conservation — are somewhat incompatible, the reservoir could be operated satisfactorily to the mutual advantage of these purposes. Single -Purpose Project Operation Box Canyon Reservoir would fill each winter because of the large annual runoff which, on the average, is six times the storage capacity. In accordance with downstream fishery requirements, releases of at least ^0 second- feet could be maintained during the summer months and yet the reservoir would fill each winter. The reservoir would normally spill during the winter, spring, and early summer, but in years of less than average water supply, the summer inflow would drop below the required release of 4o second-feet. During July, August, September, and October of some years, releases would be made from stored water to maintain the downstream fishery. These releeises, as well as evaporation, would cause lowering of the reservoir. Figxire 6 shows approximate reservoir fluctuations viiich wo-uld have occurred during the two driest periods between I9IO and i960 (1923-1925 snd 1929-1936) with the reservoir being operated as outlined above. Graphs are also -106- FIGURE 6 N0iiVA3"i3 aowjans aaivM , 1 — I — I — I — r ci 9 S5 ^ S 8 I I A.- 1 O o k-o- V I V' x UMOpMOJP JO f33J _\ O ^ ,-" i: ^ V .J r 330 NW 030 o mi- o 330 q: LlJ Q- >■ _J inr r, Q. 0. 3 W a. UJ H Nvr < D3C # _] a: Nwr UJ CO 330 UJ IE 330 Nvr 330 l|^^§8Sg§| 1 _ - ; 1 - •3 - " ^1 - r - ? • ^ ? •<3 u " ~ >. _ ■a ^ " o E \ o - - r " 1 - 330 o o o z o 3 n N»r o 330 a. n Z rr o UJ ^^ 1- < 1- o < CTl UJ 3 1- < o UJ 3 _l Nvr n- L. 330 < UJ 2 UJ O < U. (T> or IT NVf UJ > S !5 ! 1 1 1 1 1 J 1 Q> C) O O C) Q C 1 r 1 1 1 ~1 UMOp> OJP fO /a*y - , 3 - k ; - y s i - / o E - < f >, _ s^ ■c iC - ii - / II - - < - <3 1 - 330 Nvr 330 o o o (£ UJ a. a: z (T => O o CO 3 o o a: a. < S a: o O > or UJ CO UJ o > < o X o m wniva S9sn — NoiiVAana savjdns aaivM presented of reservoir fluctviations for 1959-6O, for which years records of streamflow are available. Figure 6 shovs that the worst condition in the 50- year period woiild occiir as a 24-foot drawdown in the fall of 1924. The next worst condition would be a l4-foot drawdown in the fall of I93I. Extreme lowering, such as in these two years, would occur infrequently. In I923, only 3 feet of drawdown would occur; and in 1959, only h feet of drawdown would resvilt. Between the extremes of mELximum and minimum drawdown, it is estimated that the reservoir would fluctuate between zero and 6 feet about half the time during near-normal years and between zero and 12 feet during drier years. Multipurpose Project Operation Box Canyon Reservoir, operated as a multipurpose recreation and conservation project, wovild be managed as described for a single -purpose project except during a critical period ■vdien the release would be required for down- stream water demands. The release of water from Box Canyon Reservoir would be made to aixgment downstream water projects to provide an additional increment of water to the State Water Facilities. Water stored in Box Canyon Reservoir woxold be released for this purpose only in a critical dry period. Operation studies of projects contributing to the Delta water supply were predicated upon a critical period that would probably occur once in 50 years with water supply conditions such as prevailed frcm 1928-29 through 1934-35' As indicated by these studies, surplus waters stored in Box Canyon Reservoir would be released in a year corresponding to 1929> during which year storage in Shasta Reservoir would have dropped to a low of about 1,100,000 acre- feet. Box Cajiyon Reservoir would release its entire available storage during a six- week period in the fall after the recreation season. This water wovild be conveyed to the Delta for further diversion. Box Canyon Reservoir would fill and spill during the winter and would be operated for recreation during the following stmimer. However, the water -108- stored during the critical period would be released in the fall to replace water that otherwise would be stored in Shasta Reservoir. The fall release of water from Box Canyon Reservoir would continue each year until Shasta Reservoir would spill and new surplus water covild be stored in Box Canyon Reservoir. Figure 6 shows approximate reservoir fluctuations which would occ\ir during the critical period if the reservoir were operated to augment downstream water supplies . The operation described above would permit Box Cajiyon Reservoir to maintain its normal, high-level recreation pool during the summer months, but would have an adverse effect on the reservoir trout fishery by the seasonal release of water for seven years. No doubt, many fish would be lost during the release of water, but more serious would be loss of the reservoir's food- production characteristics by the extreme fluctuation and interference with the spawning and rearing of young fish. It has been assumed that this situation could be satisfactorily corrected by planting catchable-sized fish diiring ajid after the critical period operation. The cost of the fish planting program would be assessed against the conservation p\irpose. Project Accomplishments The development of a recreation-oriented reservoir project at Box Canyon would add to the supply of water-associated recreation facilities required to keep pace with the increasing demand for facilities of this type in California. The project would provide a variety of recreation opportunities both to day-users from the Mt. Shasta City-Dunsmuir area and to campers and sightseers from all parts of the State. These recreationists would come to enjoy the fishing, boating, swimming, cajnping, picnicking, and sightseeing in the attractive setting that Box Canyon Reservoir would create. The operation of Box Canyon Reservoir as a multipurpose project to release water during a critical period would add new yield to the State Water Facilities. -109- The primary accomplishment of the Box Canyon Project, either single- purpose or multipurpose, would be to provide a i+85-acre water surface mth a shoreline and surrounding area suitable for recreation development. With Box Canyon Reservoir operated for recreation and fishery enhancement, the majcimum reservoir drawdown during the recreation season in most years would be less than 6 feet below the normal pool elevation. A stable water surface elevation in the Box Cajiyon Reservoir would create a productive reservoir trout fishery. Primary Recreation Benefits Primary recreation benefits of the Box Canyon Project were estimated in the manner described in Chapter III and are the same as those developed in that chapter to determine the justification of recreation as a separable purpose in a multipurpose project. Total primary recreation benefits at the proposed Box Canyon Reservoir therefore are estimated to be $9^^70^000 when expressed as the present worth value of annual benefits over a 50-year repay- ment period. Secondary and Intangible Recreation Benefits Economic justification of the Box Camyon Project can be based only on its primary recreation benefits, not on such secondary benefits as increased property values, new capital induced into the community smd increased local net income. Furthermore, inteingible esthetic and social benefits that woiild be created by construction of the Box Canyon Project do not lend themselves to measurement in monetary terms. Although secondary and intangible benefits do not receive consideration in project formulation, they are a factor to consider in establishing the need for the project. A study of the economic value of state parks in Oregon, for instance, revealed that park visitors stay longer in a general area because of the presence of a park. In the southern Siskiyou and northern Shasta County areas -110- surrovinding Box Canyon Reservoir, such an increased length of stay would mean greater expenditures by the recreationists. The needs of recreationists for goods and services in this general area would increase the sales at present business establishments, create the need for new businesses, and stimulate the investment of new capital in the commxmity. The resulting increased value of private property in the vicinity of Box Canyon would create an assessed valuation greater than that vrtiich exists xinder conditions without a project. As for intangible benefits, these have been stressed by recreation emd park plemners who have visited the project area and praised the high esthetic quality of the setting. Fishery Maintenance and Enhancement As previously stated, estimated primary recreation benefits include the benefits resulting from an improved trout fishery. The following paragraphs discuss the fishery aspects of a single-purpose recreation Box Canyon Project. Working with the Department of Water Resources, the Department of Fish and Game investigated possible effects of the proposed Box Canyon Project on fish and wildlife £ind presented its conclusions in a report entitled "Interim Report on the Probable Effects of Box Cajiyon Reservoir on Fish and Wildlife Resotirces of the Upper Sacramento River," Augiist I962. This study showed that the existence of a recreation reservoir at Box Canyon would result in increased natural production of trout in that portion of the Sacramento River and its tributaries in the vicinity of the reservoir. It also showed that, at no additional meuiagement expense, the expected increase probably would provide the angler with many more fish in the reservoir. Reservoir Fishery » The streams within the reservoir area presently contain resident populations of rainbow and brown trout. Blockage by Shasta Dam has eliminated the migrations of anadromous fishes lAiich at one time -111- utilized this area. The Department of Fish and Game plants catchable- sized rainbow trout in streams within the project area. However, approximately l8 times as many fingerlings could be plemted eumvially in Box Canyon Reservoir for the annual amount of money expended in recent years for planting catchables. Fingerlings experience a higher mortality rate than catchables, particularly \±ien planted in streajos, but estimates indicate that the yield of hatchery- reared fingerling trout from Box Canyon Reservoir would at least triple the present yield of the streams that would be inundated. ^ The natviral saucer- like shape of the bottom of the reservoir would provide large areas of water less thsm 30 feet deep. These areas woiild be natxiral fish food-producing areas and, coupled with spawning gravels in the tributaries to the reservoir, woiild produce a reservoir highly suited to natxiral trout production. Operation of the reservoir as a stable pool would further enhance natural trout production because such operation would preserve all food-producing areas. Increased natvxral production of trout added to the expected increase in yield of hatchery- reared fingerling trout in the reservoir would more than quadruple the present yield frcan the inundated area at no additional expense. Downstream Fishery * As a result of its study, the Department of Fish and Game made the following reconmiendations for maintensuace of the fishery downstream from the reservoir: °'-Jhen the reservoir is filling, tlie folloving tentative releases, or the actual flo^.;-, ■'.whichever is less, should be raade: January and February: I50 second -feet March, April, and May: 100 second-feet June and July: 75 second-feet August and Septenber: 50 second-feet October: 75 second-feet IToveniber and December: 100 second-feet -112- After the reservoir fills, a fishery maintenance flow consisting of the actual inflow to the reservoir, minus evaporation, should be released below the proposed dam, except that the release should never be less than i+0 second -feet. ^'Ihe reservoir pool should not be drawn below elevation 3^lS0 feet (lO feet below normal pool) without prior approval of the Department of Fish and Game. This restriction might neces- sitate a compromise between the maintenance of a downstream relesise and the reservoir stage during am extremely dry year. ^Provisions for a high-level and a low-level outlet should be included in the dam design. Each outlet should have a capacity of at least 50 second-feet. The high-level outlet should be provided with a suitable screen to prohibit fish from leaving the reservoir.* °Plans for installing a thermograph at the Department of Water Resources' gaging station below Box Canyon (Sacramento River neeir Mt. Shasta) should be put into effect at the earliest possible date. Water tenrperature data should be collected from the time of installation until five years after project completion to aid in determining the proper temperature of the release. Reg-olation of suinmer flows and control of water temperatures doi'/n- stream from the dam may improve the present fishery, but, with data available d\jring this investigation, prediction of specific enhancement was not possible. Water Conser\'"ation Benefits Box Canyon Reservoir would store 30,000 acre-feet of water at the normal pool elevation of 3>190 feet, USGS datum. Of the total storage capacity, 5,000 acre-feet would be reserved as inactive storage for preservation of fishlife, an additional 5^000 acre-feet would be carried over and released as needed to replace increased evaporation caused by summer holdover in Box Canyon Reservoir. The remainder of 20,000 acre-feet would be available for release for doimstream needs. To compute the benefits accruing to Box Canyon Reservoir for the development of new yield, it was assumed that the entire release of 20,000 acre-feet would be transported to the Sacramento -San Joaquin Delta and from there be diverted by *The design of the proposed Box Canyon Dam and Reservoir has incorporated the suggestions in this item. -113- the State Water Facilities. The release and diversion of 20,000 acre-feet during one lov-supply year of the critical dry period vould be equivalent of a firm annual yield of 2,900 acre -feet. In effect, the provision of 25,000 acre -feet of active storage at Box Canyon Reservoir would allow the entire system contributing to the Delta diversion to be operated each year to produce an additional 2,900 acre -feet. The benefits wotild begin accruing to Box Canyon Reservoir in I982, when estimated increased water demands would exceed the initial capacity of the State Water Facilities. Benefits accruing to the Box Canyon Project over the remaining 38 years of the repayment period, but reduced to present worth in 1970, were estimated to be $1,^4-23,000. A unit annual benefit of $4o per acre-foot is cvirrently (1962) being used in evaluation studies of the State Water Facilities and is applicable to analyses of future projects whicli may develop water supplies for export from the Delta Pool. Engineering Feasibility and Economic Justification Investigation results indicate that the Box Canyon Project as formiilated possesses engineering feasibility and meets those req.uirements of engineering feasibility presented at the stai't of this chapter: °The water supply is adequate in quantity and quality for the proposed size of the project. °Tlie dam and reservoir sites are geologically suitable for the proposed structures and their uses (provided that geologic problems receive proper consideration during final design and construction). ^Design and construction possibilities are such that the proposed uses of the project will be served efficiently and safely. •^Construction is possible with available materials and present techniques at reasonable cost. Single-Purpose Project For the Box Canyon Project, formulated as a single -purpose recreation project, to be economically justified, its recreation benefits must exceed the entire cost of the project. The present vorth value of recreation benefits throughout a 50-year repayment period (1970 to 2020) was estimated to be $9, ij- 70, 000. The total capital cost of the project, based on I96I price levels and including the present worth value of future expenditures for additions, operation, and maintenance, was estimated to be $8,^4-03,000. The resulting benefit-cost ratio, 1.13 to 1, indicates economic justification. As previously noted, secondary benefits were not inclioded in project benefits. However, consideration of secondary benefits resulting from increased income to the l-It. Shasta City-Dunsmuir area would increase the degree of economic justification. Multipurpose Project With the Box Canyon Project designed and operated as a multipurpose project for recreation and water conservation, the project benefits, cited above, would be reduced by $35^000 due to loss of recreation benefits from fishing use, but would be increased by $1,^23,000 due to water conservation benefits. The resulting project benefits tliroughout the 50-year repayment period were estimated to be $10,858,000. The total capital cost of the multipurpose project, includ- ing the items cited above for the single -purpose project and with the higher cost of the outlet works, was estimated to be $8,72^,000. The resiilting benefit-cost ratio of 1.24 to 1 indicates economic justification. Cost Allocation An estimate was made of the proportions of the cost of the multipurpose project that could be allocated to the recreation and water conservation purposes in accordance with the separable costs -remaining benefits method. For each of the pxirposes, the benefits set forth above would be limited by the least costly alternative. The benefits accruing to recreation under the multipurpose project would be limited to the cost of the single -purpose recreation project -115- ($8,i+-03,000). The conservation benefits would be limited to $356,000 under the assumption that new yield could be added to the Delta at a cost of approximately $10 per acre- foot from alternative sources. The separable costs of the recreation and conservation purposes were computed to be $4,107,000 and $321,000, respectively. It was found that approximately 99 percent of the remaining benefits would accrue to recreation and 1 percent woiold accrue to conservation. On this basis, the total project costs vrould be allocated in the araoimts of $8,368,000 to recreation and $356,000 to conservation. Thus, it laay be seen that even with the addition of the water conservation purpose to the Box Canyon Project, nearly all the costs (96 percent) would be attributed to recreation. Project Selection In Chapter III, an analysis was made of the possible project purposes that could be included in a reservoir development project at the Box Canyon site on the Upper Sacramento River. The possible purposes investigated were recreation, flood control, hydroelectric power, irrigation, municipal and industrial uses, and new water yield to the Sacrajnento-San Joaquin Delta. It was found that only the purposes of recreation and new yield to the Delta v/ould create benefits equal to or larger than their separable costs. In the preceding sections of this chapter, it was shown that a reservoir development at the Box Csinyon site could be formulated either as a single-purpose recreation project, or as a multipurpose recreation and water conseirvation project. Either project would be economically justified. However, it was indicated that there is a significant degree of uncertainty regarding the benefits that may accr'ae to the new Delta yield purpose. One such item is the small amount of water involved in the Box Canyon -116- Project in comparison to the Central Valley Project and the State Water Facilities. Another, and probably the most serious item, is the amoiint of the estimated benefit assuming that water from Box Canyon Project woiild be added to the State Water Facilities in I982. If the Box Canyon Project yield were not added vintil some years later, the benefit would probably be less than the estimated separable cost. Also, operation of the water conservation pur- pose as described in this chapter would be incompatible in some degree with operation of the Box Canyon Reservoir for recreation and fishery enhancement. It was, therefore, concluded that the Box Canyon Dam and Reservoir Project shoxild be formulated and given further consideration as a single- purpose reservoir recreation project. As previously mentioned, no alternative water development project has been proposed that vrauld fiilfill the estimated recreation demand to the extent described for the Box Canyon Project. State Park System Development The Division of Beaches and Parks of the Department of Parks and Recreation has prepared a report entitled "Mt. Shasta-Siskiyou Area Study-- An Analysis of State Park Potentials in Western Siskiyou County," dated January 2, I962, in response to Senate Concurrent Resolution No. kS and Assembly Concurrent Resolution No. 87 of the I96I legislative session. This investigation and analysis identified five possible park and recreation projects, including the Box Canyon Project, that would be desirable additions to the State Park System. The above report recommended these be adopted as official projects of the State Park Program and that additional detailed planning and studies be performed. The Division of Beaches and Parks considered establishment of park facilities in the Box Canyon area both with and without a reservoir as proposed by the Department of Water Resources. Both developments were -117- found to be desirable, and the Division of Beaches and Parks estimated that recreation use with the reservoir would be nearly double that without a reservoir. During the I962 calendar year, the Division of Beaches and Parks gave more detailed study to plans for a State Park System development in conjunction with the Box Canyon Reservoir recreation project as proposed in this Bulletin No. 100. This work was coordinated with the studies of the Department of Water Resources and resulted in substantial agreement in all phases of the planning. However, to establish a State Park System development at Box Canyon, the Division of Beaches and Parks would desire acquisition of lands in addition to those described in this bulletin as the reservoir recreation project area. State Park System Lands Cost estimates of the Box Canyon Single-Purpose Recreation Project as previously presented were predicated upon acquisition of 2,088 acres considered as the minijjnua reservoir recreation project area to provide for the dam and reser- voir, and for lands for recreation facilities to meet the estimated water- associated recreation demands. Standards of the Department of Parks and Recreation for establishment of a State Park System development at Box Canyon wovild require acquisition and management of lands in swidition to those delineated for the reservoir recreation project area to provide for uses other than water- associated recreation. Acquisition of an additional 2,330 acres on the south and west of the reservoir project boundary would provide complete public access to adjoining lands of the U. S. Forest Service, Shasta National Forest. The Department of Parks and Recreation foresees many recreation benefits forthcoming from the opportiinity for visitors at the Box Canyon Project to visit and make use of the Castle Lake-Gumboot Lake area. Their January I962 report states, "Working on a cooperative basis with the Forest Service, we would help bring about realiza- tion of the total recreational potential of this beautiful area." -118- Management of the recreation area would be enhanced by acquisition of U30 acres to the north of the reservoir recreation project boundary to include lands within the immediate watershed along Rainbow Ridge to the north. One of the purposes of these additional lands would be to preserve the scenic character of the lands surrounding the proposed park area. Another would be to protect and preserve the quality of runoff from the immediate watershed which may otherwise be subject to degradation from residential or commercial development . The addition of these lands to the reservoir recreation area would increase the project area for a desirable State Park System development to about 4,800 acres. It is estimated, without actually appraising the additional lands, that the increased cost to the project would be about $350,000. Need and Implementation The Mt. Shasta City-Dunsmuir Area Investigation was initiated in response to the need expressed by residents of the area for development of their local water resources. Throughout the period of the investigation, there was continual awareness by local residents and particvilarly the Siskiyou County Board of Supervisors in the engineering studies and results as presented herein. It was not foreseen that the most desirable water resources development at the Box Canyon site wovild be a single-purpose recreation project. Rather, it was expected that the various multipurpose uses analyzed in Chapter III would prove justifiable and would contribute to the finaxicial feasibility of the project. Nevertheless, there is strong local support for construction of Box Canyon Dajn and Reservoir as a single-purpose water project, because such construction and operation would be a valuable addition to the local economy, much of \Aich is based on recreation. Increased recreation activity is viewed as a means to replace incomes lost to Siskiyou County by declines in lumbering, mining, and steam railroad equipment maintenance. -119- No formal investigation vas made of the ability of a local agency in Siskiyou County to finance and construct a recreation reservoir project at Box Caxiyon. However, this appears unreasonable because only a part of the benefits would accrue to the local area. Most of the primary recreation benefits as computed herein and presented as the basis of economic justifica- tion would accrue to the recreation users and visitors v*io reside in other parts of the State. Therefore, it is considered that implementation of the Box Canyon Project would be dependent upon state financing, construction, sind operation as a unit of the State Park System. ■-''•' Advance Planning Program In the event of legislative authorization for construction of the Box Canyon Project, an advance planning program would be required to establish the final criteria needed to prepare construction plans and specifications. The advance planning program would include additional geologic studies and drilling of the damsite, final sizing of the structures, detailed layout of on-shore recreation facilities, and other state park facilities. Programs would be established for operation and maintenance of the reservoir, the state park and recreation facilities, and for fish and game management for the purposes of designs of facilities. Arrangements would be made for relo- cation of roads, utilities, and related items that would affect establishment of final design criteria. Emphasis wo\ild be given to further geologic exploration of the Box Cajiyon damsite to resolve questions concerning foundation conditions and possible seepage through the left abutment. It is proposed that five to seven diamond-drill core holes, totaling about 1,200 feet, be drilled to determine the physical nature, thickness, and grouting requirements of the -120- volcanic rock beneath the channel. Cable tool drilling is proposed on the higher portions of the abutments to determine the subsiirface natiire, thickness, and permeability of glacial and lake sediments. Further mapping, sampling, and testing would be done to locate and evaluate construction materials for the earthfill dam. It is estimated that the advaxice planning program vould be carried out throiagh one fiscal year at a cost to the Department of Water Resources of $115,000. The program would be completed in the subsequent fiscal year at an additional cost of $7^000 for technical staff review, editing, and publication. The resvilts of the program would provide data and criteria needed to prepare construction plans and specifications. The cost of final plans ajid specifi- cations is included in the estimated cost of construction of the project. •121- CHAPTHl V. CCaJCLUSICKS AND RECQMMENDATICNS In the Mt. Shasta City-Ihinsmuir area, located at the headwaters of the Sacramento Kiver, where in the past agriculture, lumbering, and the railroad have provided its economic livelihood, recreation is rapidly becoming a new major industry. Local residents foresee development of the local water resources as another step toward development of a year-round vacation land. Determination of the engineering feasibility and economic justifi- cation of a multipurpose dam and reservoir at Box Canyon on the Sacramento River about 2 miles southwest of Mt. Shasta City was requested by local interests, and subsequently was made the objective of this investigation. The following conclusions and recommendations are based upon analysis of data collected and developed for this investigation during field and office studies. Conclusions 1. The Mt. Shasta City-Dunsmuir area possesses a scenic environment and climate ideally sviited for both summer and winter recreation. The area, served by major transportation routes, is visited by increasing numbers of rec reationists . 2. The portion of the Sacramento River Basin above Box Canyon damsite produces an abundant water supply. The 122 square mile drainage basin has an estimated average annual impaired runoff of 192,000 acre-feet, 3. The porous lower slopes of Mt. Shasta contain ground water which supplies hundreds of continuously flowing springs. These springs sustain flows in the Sacramento River and its tributaries during the summer months when little or no rainfall occurs. -123- U. The combination of good water supply and evident dam and reservoir sites at Box Canyon has long suggested that water storage facilities here would be of value to the Mt. Shasta City-Dunsmuir area. Investigation of the separable purposes envisioned for a multipurpose reservoir at Box Canyon resxilted in the following conclusions: a. Flood Control . In its present state, the Sacramento River poses a flood threat to the Dunsmuir-Castella area. However, the relative infrequency of dajnaging floods and comparatively small amount of damages that could be prevented by a reservoir at Box Canyon would not economically justify the inclusion of flood control measures in a reservoir project at Box Canyon, b. Hydroelectric Power . Future demands for electric energy in this area could be supplied, in part, by hydroelectric generation at Box Canyon Reservoir, However, computation of benefits based on cost of energy from the most likely alternative source indicates that total annual benefits would be less than the annual cost of power facilities. Generation of hydroelectric power was not included in the final project, c. Irrigation . The Wagon Creek Valley area would have no demand for irrigation water from a reservoir at Box Canyon because less expensive water could be developed from creeks, springs, and ground water sources. Although a large demand for water exists in Shasta Valley, the cost of transporting Sacramento River water to Shasta Valley would exceed the payment capacity of Shasta Valley water users. Therefore, use of project water for irrigation was not included in final project formiilation* d. Mimicipal and Industrial Uses . Study of present and future municipal and industrial water supplies within the project area showed that additional development of presently used and alternative supplies would be more economical than use of project water. Consequently, municipal -12U- and industrial water development was not included as a purpose in the final project, e. New Water Yield to Sacramento-San Joaquin Delta . Proper operation and release of water stored in Box Canyon Reservoir would provide new water yield to the Sacramento-San Joaquin Delta during a water-short critical period. The benefits derived from new yield would equal the cost of in- cluding the purpose in the project and of restoring the fishery which would be temporarily disrupted. f . Recreation . The demand for recreation areas and facilities in the Mt. Shasta City-Dunsmuir area was found to exceed the supply. The benefits derived by including recreation as a purpose of a reservoir development at Box Canyon were shown to exceed the cost of the project. 5. Box Canyon Dam and Reservoir with a storage capacity of 30,000 acre-feet could be formulated either as a single-purpose recreation project, or as a multipurpose project for recreation and water conservation to supply new yield to the Delta. 6. Field and office investigation of the possible damsites at Box Canyon showed that the upper damsite located approximately 1,000 feet down- stream from the Mt. Shasta City-Castle Lake road would serve most efficiently the recreation purpose of the project. 7. Geologic investigation revealed that the damsite would be suitable for a zoned earthfill dam with crest elevation of 3,215 feet. Further investi- gation of the damsite and further study of available construction materials would be necessary before construction designs could be completed. 8. The dam and reservoir to be included in the Box Canyon Project as described in Table l8 would comprise a 220-foot high earthfill dam at the upper site capable of storing 30,000 acre-feet of water at a nonnal pool (spillway lip) -125- elevation of 3>190 feet, USGS datum. The water surface area at the normal pool elevation would be Ii.85 acres and at maximum water surface elevation would be 6l5 acres. 9. Camping provided by the project would be the major attraction, although day-use in the form of fishing, picnicking, swimming, and boating would attract many additional recreationists from the local area. Sightseeing also is expected to attract large numbers of recreationists. 10. In accordance with estimated demands for recreation use at the Box Canyon Project, it is estimated that initial recreation facilities installed to State Park System standards would include 2U5 camp units, $0 picnic units, sanitary facilities, water supply, access roads, beach improvement, boat launching ramps, overlook area for sightseers, parking lots, and concessions. Initial operation would provide for 125,000 visitor-days annually, estimated to occur in 1970. 11. The Box Canyon Project, with suitable recreation facilities, would satisfy an estimated demand of 125,000 visitor-days during the first year of operation and with properly expanded facilities would serve an estimated demand of 673,000 visitor-days at the end of $0 years. The present worth of total recreation benefits over the 50-year period would be $9,U70,000, 12. The Box Canyon Project would enhance the fishery both within the reservoir area and downstream from the reservoir. Box Canyon Reservoir could be operated to maintain a nearly constant water surface during the entire year and still maintain adequate downstream flows for stream fishery enhancement. The reservoir, however, would inundate some intermediate deer range which would require replacement adjacent to the project area. 13. When operated for new yield to the Sacramento-San Joaquin Delta by releasing 20,000 acre-feet during one to two months of the critical period, -126- it would provide a new firm yield comparable to 2,900 acre-feet per year. A minimum pool of 5*000 acre-feet woiild be maintained in Box Canyon Reservoir, The reservoir would fill each winter following the conservation release but would have to return this water to Shasta Reservoir each fall until new surplus water that would otherwise spill from Shasta could be stored. The benefits creditable to this purpose were estimated to be $1,14.23,000. lU. The detriments to the fishery and recreation aspects of the project would be offset by planting fish each season during the critical period conservation operation. The additional costs of the fish planting program, expressed as the present worth of costs throughout the repayment period, would be $272,000. In addition, recreation benefits attributable to fishing would, be reduced by $35»000 over the same period. 15. The Box Canyon Project demonstrates engineering feasibility because: a. The water supply is adequate to meet the requirements of a reservoir used for recreation and downstream fishery enhancement. b. The damsite is suitable for the dam proposed. c. NatursLl materials for construction of the dam are available in siifficient quantity. 16. The costs of both the single-purpose and multipurpose recreation projects are shown in the following tabulation: J. : Single -purpose : Multipurpose ; recreation project ; project Initial expenditures $4,788,000 $4,837,000 Future expenditures^/ 3,61^,000 3 » 887, 000 Total $8,403,000 $8,724,000 1/ Includes present worth of future capital costs and annual outlay for operation, maintenance, and replacement. -127- 17. A single-purpose recreation project at the Box Canyon site as described herein would create total benefits of $9,^70,000 and would have a toted, project cost of $8,403,000 over the 50-year repayment period. The resulting benefit-cost ratio of 1.13 to 1 indicates economic justification. 18. A multipurpose recreation and conservation project at the Box Canyon site as described herein would create total benefits of $10,858,000 aind would have a total project cost of $8,724,000 over the 50-year repayment period. The resulting benefit-cost ratio of 1.24 to 1 indicates economic justification. 19. An allocation of the multipurpose project costs to each purpose in accordance with the separable costs-remaining benefits method indicates that 96 percent of the costs would be creditable to recreation ajad 4 percent to conservation. 20. It is concluded that the most desirable project to be constructed at the Box Canyon site would be a single-purpose recreation and fishery enhance- ment reservoir project operated as part of the State Park System. This selec- tion was made because of the small quantity of water to be developed by the conservation purpose, the uncertainty of the accrual of benefits, and the incompatibility of operation of the proposed reservoir for water conservation in conjunction with recreation and fishery enhancement piirposes . 21. The State Division of Beaches and Parks has determined that the Box Csuiyon area possesses high potential for state park development with- out a reservoir, and an even higher potential for development sho\ild a reser- voir be constructed at Box Canyon. 22. Development of a reservoir recreation project at Box Canyon would help satisfy growing statewide demands for outdoor recreation facilities and would augment economic conditions in southern Siskiyou County by increased recreation activity. Box Canyon Reservoir would provide trout fishery -128- enhancement. A state park system development would provide public access to an extensive area of National Forest lands in the Castle Lake-Gumboot Lake area. 23. Ko alternative project ^vas found that would fulfill the needs described above to the extent demonstrated for the Box Canyon Project. 24. Implementation of the Box Canyon Project wo\ald be dependent upon state finemcing, construction, and operation as a unit of the State Park System. Recommendations It is recommended that: 1. Box Canyon Dam and Reservoir Project set forth herein as a single-purpose reservoir recreation project be authorized and constructed as a imit of the State Park System and that the area of the unit be not less them the proposed recreation area shown on Plate 3« 2. The Department of Water Resources be authorized to proceed with acquisition of lemds necessary for establishment of the reservoir recreation project, to complete advajice planning to define criteria for final design, to prepare construction plans and specifications, and to take all steps necessary to construct the project, including recreation facilities, and to provide for future maintenance of Box Canyon Dam and Reservoir. 3. Additional funds in the amount of $115,000 be added to the Department of Water Resources 1963-6i|- budget to provide for advance planning and geologic investigation of the Box Canyon site. k-o The Department of Parks and Recreation give consideration to a program for acquisition of additional lands, outside the proposed recreation area cited above, to provide for state park purposes other than water-associated recreation; and further, upon approval of funds for advance planning, enter into a cooperative agreement with the Department of Water Resources to do detailed planning of recreation facilities at the proposed Box Canyon Reservoir. -129- PLATE I T.43N '^^l >T.42N. \0 T.4IN. T40N. OREGON AREA OF INVESTIGATION SAN F«ANC ISC' SAN MATEO SANTA CBUZ Esperant> 'c, T39N. LEGEND BOUNDARY OF SACRAMENTO RIVER BASIN BOUNDARY OF DRAINAGE AREA ABOVE BOX CANYON DAM SITE IRRIGABLE LANDS FLOOD DAMAGE AREA _co_ , CO, "^ gs BOUNDARY OF MI SHASTA CITY- OUNSMUIR AREA fc) T.38N. ^T37N. «BLO B a M 1^ STATE OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES NORTHERN BRANCH MT. SHASTA CITY-DUNSMUIR AREA INVESTIGATION PROJECT AREA 1962 ^ SCALE OF MILES 2 Contour Inlervoi 500 Feet - U- S G S DotuiTi STATE OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES NORTHERN BRANCH MT. SHASTA CITY-DUNSMUIR AREA INVESTIGATION PROJECT AREA 1962 SCALE OF MILES Contour Inlarvol 500 Feel - U, S G S Oolui E.>U«^ p..i^ "*"'" M~* R.i.rJ irw-iTu "("iTiSr"' P.«-|.«t.-.SBl,-.. Azmi unB _. Aiisn UW8 fivtn OiwB I4«.d.» 118 s~c»». , DWR J) ma » mm II<7 Mo Cn B«t Lrt.. WR n i.«. 0«,«., SwMi WTKB ■ d^C-.>IUI>.MJIIiRo«k Uq-0« IKO Skhhoh !)>..• 6><...n HIdll. F^ & N.XK F«k ... ow jMlt«>C 1W) ■UMB-L LEGEND ^B BEACH AREA I I I'ICNIC AREA ^^ CAMPING AREA I I BOAT LAUNCH I I NATURAL AREA I I OVERLOOK AREA I I CONCESSION AREA SHASTA NATIONAL FOREST BOUNDARY PROPOSED RECREATION AREA BOUNDARY Minimum reservoir recreation project area to provide for dam and reservoir, and recrea- tion facilities to meet water-associated recrea- tion demand. STATE OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES NORTHERN BRANCH MT, SHASTA CITY-DUNSMUIR AREA INVESTIGATION BOX CANYON RESERVOIR RECREATION LAND USE PLAN 1962 [mm STREAM CiUVEL 1HAJT« GLACIAL DRIFT ICLUMTH CLaOAL ORIFI a aociv If sriRKCASCOC raLCua; INTRtniVE COHPLEK COPLEY GREENSTONE COHTICT, U>FROl>lUTfU U OHTtCT, CONCEALED STATE OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES NORTHERN BRANCH MT SHASTA CITY-DUNSMUIR AREA INVESTIGATION BOX CANYON DAM SITE AREAL GEOLOGY 1961 SECTION B-B' /• ^^--^ ~> 9 s y .__;^ \^ -•TOrc I; m ^ ^\^ 09 Tw -S9.Jl^^ R. ., ^ ' '■' ^ I r Tw c S . ■ U - ~' "i" 160 !« J!0 •oc MAI WS ElEV S?iO - ■ S ■^ -"' LWAY OlSCHARGt .^O 3 MGO " ""' .„ y 1 CAPACITT \ / ' 1 / 1 9 ^'^ 3 / t d / / A Ij /»-J0UTL^T WORKS DISCHARGE 1 ? ,„ If A 1 / ^ ^ _ CAPACIiy IN TMOUSAMS OF ACRE-« AREA-CAPACITY-DISCHARGE CURVES 6*0 800 'ELEV 30«S' STATE OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES NORTHERN BRANCH MT SHASTA CITY-DUNSMUIR AREA INVESTIGATION BOX CANYON DAM GENERAL PLAN AND SECTIONS 962 INC DOWNSTREAM THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW BOOKS REQUESTED BY ANOTHER BORROWER ARE SUBJECT TO IMMEDIATE RECALL FEBl^JiZf pet — i APR 1 ml PHYS SCI LIBRAPIY JUN3 01990 ^ i|?eceivzd: set UBF?i\B« MOV2n989Rl£ NOV 2 ^ HtU U FHYS SCi LtBhA^ LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS Book Slip-Series 458 3 1175 01004 3555 nATTf niTu Cai;f. Water Res urces De^t. Mt.. Slnsts Investieation TIES , 1963 BORROWER'S NAME liii mill ■■III 1 tin ii mm iliii iT.!<'(':\- mm ii.:!8 •m mm hi mm m m mm pWmmm