REGIONAL DIRECTOR'S REPORT OF DECEMBER 1950 To: Commissioner. DEPARTMENT OF THE INTERIOR, BUREAU OF RECLAMATION, REGION 4, From: Regional Director. Subject: Interim report on Colorado River storage project and participating projects, upper Colorado River Basin. 1. This letter is submitted as my interim report on the potential Colorado River storage project and other reclamation projects that would participate in the benefits and revenues of the storage project. The report outlines a plan of development and recommends an initial construction program. As investigations progress, further recommendations for construction will be made through other interim reports. The plans and programs of Federal agencies cooperating with the Bureau of Reclamation in the storage project investigations are a part of this report. Substantiating materials for the storage project, including statements of cooperating Federal agencies, are appended. Supplemental reports cover the details of each participating project. 2. The Colorado River storage project would consist of a combination of dams, reservoirs, powerplants, and other appurtenant structures on the upper Colorado River and its principal tributaries. Included as appurtenant structures would be facilities recommended by cooperating Federal agencies for multiple-purpose development of the upper Colorado River Basin's water resources. The project reservoirs would regulate the flow of the river, assure the delivery of water to the lower basin as required by the Colorado River compact, and further the use in the upper basin of water apportioned by the compact. Part of the capacity of some of the reservoirs would store water for direct use in the upper basin. Revenues from the sale of project-generated power would be suff cient to pay all reimbursable Colorado River storage-project costs and assist irrigators in payment of costs of other projects that would utilize water of the upper Colorado River system. Projects that would be so assisted are referred to as "participating projects." All projects authorized subsequent to approval of the upper Colorado River Basin compact that would consume water of the upper Colorado River system are considered to be dependent on the storage project for an assured water supply. Such projects, therefore, are designated "dependent projects." 3. Authority to make this report and supporting investigations is provided in the Federal reclamation laws (act of June 17, 1902, 32 Stat. 388, and acts amendatory thereof or supplementary thereto, particularly the Boulder Canyon Project Adjustment Act, 54 Stat. 744). 4. Important contributions to this report and the substantiating materials were made by the Upper Colorado River Compact Commission and States of the upper Colorado River Basin. Valuable background information on the Colorado River Basin, its present and potential development, its resources, needs, and problems, was obtained from The Colorado River, a Department of the Interior report, dated March 1946, and printed as House Document 419, 80th Congress, 1st session. COMPACT AND TREATY OBLIGATIONS 5. In its studies the Bureau of Reclamation has taken full account of agreements affecting the use of Colorado River system water in the upper basin, namely, the Colorado River Compact signed in 1922, the Mexican Water Treaty signed in 1944, and the upper Colorado River Basin compact signed in 1948. The Colorado River compact apportions the use of certain quantities of Colorado River system water to the upper and lower basins and establishes the obligations of Colorado, New Mexico, Utah, and Wyoming, designated "States of the upper division," with respect to deliveries of water at Lee Ferry. Rights of Mexico to the use of water from the Colorado River system are defined in the Mexican Water Treaty. By the upper Colorado River Basin compact the use of water apportioned the upper basin is divided among the upper basin States and principles are established to govern deliveries of water to meet the Lee Ferry flow obligations. 6. The upper basin, as defined by the compacts, means "those parts of the States of Arizona, Colorado, New Mexico, Utah, and Wyoming within and from which waters naturally drain into the Colorado River system above Lee Ferry, and also all parts of said States located without the drainage area of the Colorado River system which are now or shall hereafter be beneficially served by waters diverted from the system above Lee Ferry." The compact definition of the upper basin is used in the report. For distinction, the natural river basin above Lee Ferry is referred to as the upper drainage basin. Ferry, the dividing point on the Colorado River between the upper and lower basins, is located in northern Arizona. It is defined by the Colorado River compact as "a point in the main stream of the Colorado River 1 mile below the mouth of the Paria River." NEED FOR DEVELOPMENT Lee 7. Now that the upper basin compact has become effective, urgently needed irrigation projects may be undertaken to turn dry land into productive farms and to supplement the meager water supply on some presently irrigated land. An urgent need also exists for water developments to supply municipalities and to permit utilization of the upper basin's vast resources of hydroelectric power, fuels, oils, phosphate, other minerals, and timber. The States of the upper division, however, can realize the use of their apportioned water only when extensive river regulation is provided to assist them in meeting downstream flow obligations established by the Colorado River compact. With full use of water apportioned the upper basin, an aggre gate active reservoir capacity of at least 23 million acre-feet will be required to assure upper division deliveries at Lee Ferry, exclusive of any deliveries required for Mexico. In addition, capacity must be provided for sediment, power head, and direct use of water in the upper basin. 8. Electric energy requirements are rapidly increasing in the area within and adjacent to the upper basin. In recent years the growing industrialization of the West and the accelerated development of natural resources have taxed existing generating facilities to capacity. Practically every power utility in the market area has plans to increase its generating capacity to meet requirements of the immediate future. By 1980, however, power demands in the area are expected to exceed by far the output of all the installations now scheduled, including installations planned for the Colorado River storage project. Power demands in the lower basin are even greater than those in the upper basin and are expected to increase at a rapid rate. River regulation and sediment control are needed at an early date to assure maximum utilization of several important power potentialities on the Colorado River below Lee Ferry and above Lake Mead. PLAN OF DEVELOPMENT 9. The plan of development is presented by a discussion of the Colorado River storage project, followed by a discussion of participating projects. COLORADO RIVER STORAGE PROJECT 10. Ten units, each including a dam, reservoir, and appurtenant power facilities, would constitute the Colorado River storage project. The dams would be located above Lee Ferry on the Colorado River and its principal tributaries. Eight of the dams would provide river regulation, namely, Whitewater Dam (Whitewater unit), Cross Mountain Dam (Cross Mountain unit), Blue Mesa Dam (Curecanti unit), Echo Park Dam (Echo Park unit), Ashley Dam (Flaming Gorge unit), Glen Canyon Dam (Glen Canyon unit), Gray Canyon Dam (Gray Canyon unit), and Navaho Dam (Navaho unit). The two additional dams would be built for power head only. One would be the Crystal Dam (Crystal unit) which would benefit from river regulation provided by the upstream Curecanti Reservoir. The other would be the Split Mountain Dam (Split Mountain unit) which would benefit from upstream regulation provided by the Echo Park Reservoir. The various units would be constructed and operated by the Bureau of Reclamation in a manner consistent with agreements affecting the Colorado River. Title to the works would remain in the United States. Information on the 10 potential units is summarized in the following table. The extent of storage, if any, required for assistance in the administration of the Mexican Water Treaty cannot be determined at this time. The plan outlined herein does not provide for, nor preclude, storage for this purpose. 1 Would benefit from upstream storage. Storage at site would be used only for short period power regulation. 11. Investigations to date show that the project as planned would economically provide maximum water utilization and power production with minimum loss of water from evaporation. The project would control sediment, abate floods, facilitate recreational development, and aid in fish and wildlife conservation. As detailed studies progress, some changes in the selected units may be found desirable. So far as practicable, adjustments in the plan also will be made from time to time to accommodate supplemental works proposed by interested State and Federal agencies. Storage system 12. Project reservoirs initially would have a total capacity of 48,555,000 acre-feet, including 37,530,000 acre-feet of active storage and 11,025,000 acre-feet of inactive storage. In a 200-year period at the present rate of erosion, about 20 million acre-feet of capacity would be required for sediment storage nearly 80 percent of which would be provided at the Glen Canyon site. An estimated 11,589,000 acre-feet of the sediment would settle out in the active storage sections, leaving at the end of 200 years about 25,941,000 acre-feet of active capacity for river regulation and direct use of water in the upper basin. The remaining 8,411,000 acre-feet of sediment would find its way to the dead-storage pools, leaving about 2,614,000 acre-feet of inactive capacity for power head, fish propagation, and recreation. The silt deposits would not reduce the original power head. With reduced erosion on the watersheds by improved practices of land management agencies, the period of protection against sediment encroachment would be extended. Future generations could further extend this protection by developing additional upstream sediment storage sites. 13. With full use of water apportioned the upper basin, an active storage capacity of at least 23 million acre-feet would be maintained exclusively for river regulation. The space reserved for river regulation would remain nearly full as long as the river flow was sufficient to meet the 10-year Lee Ferry flow obligation of the Colorado River compact. During periods of critically low flow, water from the regulatory reserves would be released to meet the 10-year Lee Ferry flow obligation. The reserves would be replenished during years of favorable water supply. 14. Some of the regulatory reservoirs may provide direct storage for irrigation and other water-consuming uses in the upper basin. For example, water for the central Utah project could be provided by a gravity diversion from the Flaming Gorge Reservoir or by pumping from the Echo Park Reservoir. The Whitewater Reservoir by providing replacement water for use on presently irrigated land in western Colorado could permit new irrigation and industrial developments on the west slope of the Continental Divide in Colorado and transmountain diversions to the east slope of the Divide, also in Colorado. Only through the Navaho Reservoir could New Mexico attain full use of its apportioned water. Water from the Navaho Reservoir could directly supply the Shiprock Indian project, the South San Juan project, or by exchange it could benefit possible projects for the exportation of water to the Rio Grande Basin in Colorado and New Mexico. 15. Initial filling of the project reservoirs may require temporary adjustments in the operation of power facilities on the Colorado River below Lee Ferry. Any adjustments required, however, could be accomplished without prejudice to developments both above and below Lee Ferry. Because of their strategic location, the large Glen Canyon Reservoir and powerplant would be of particular importance in effecting the proper integration of power and river operations. Power development 16. Powerplants at the 8 regulatory reservoirs and at the Crystal and Split Mountain sites would have a total installed generating capacity of 1,622,000 kilowatts. Power generation would reach a maximum of about 9 billion kilowatt-hours annually and would decrease to about 6 billion kilowatt-hours annually with ultimate upstream depletions. Transmission lines would connect the plants with various load centers, either directly or through interconnections with other power systems. Energy requirements in the project service area would be met first from existing and potential local power developments not included in the project. Additional requirements would be met with energy produced by the project facilities. Construction schedule 17. The project units would be constructed as required to meet the needs for consumptive use of water and for electric energy. To make certain that project units could be in operation when needed, consideration must be given to cyclic shifts in runoff conditions and the advantages that would be gained by initial filling of the reservoirs while unused apportioned water is available. The Echo Park, Flaming Gorge, Glen Canyon, Navaho, and Whitewater units are scheduled for initial construction. Construction of the Whitewater, Echo Park, and Glen Canyon units could be undertaken immediately, followed by the Navaho and Flaming Gorge units. 18. The initial five units are favorably situated to supply immediate power market needs in the upper basin and adjacent areas. The Echo Park unit would provide a large amount of power and extensive river regulation with small losses to evaporation. The Echo Park Reservoir would not be seriously impaired by sediment. The Glen |