Annual Report Operation of the Colorado River Basin 1980 Projected Operations 1981 Colorado River Basin Wyoming Nevada New Mexico In May of 1981, the Secretary of the Interior ap­ proved changing the Water and Power Resources Service back to its former name, the Bureau of Reclamation. All references in this publication to the Water and Power Resources Service should be considered synonymous with the Bureau of Reclamation. Contents U.S. Department of the Interior Bureau of Reclamation January 1981 (Prepared pursuant to the Colorado River Basin Project Act of1968, Public Law 90-537) Sandstone formations tower above Lake Powell London Bridge and English Village at Lake Havasu Citrus Harvesting Introduction .................................................. .. 2 Authority for Report ............................... .. 2 Actual Operations Under Criteria-Water Year 1980 ...................... .. 2 Projected Plan of Operation Under Criteria-Water Year 1981 ............... .. 3 Determination of "602(a) Storage" ................................ .. 3 Mexican Treaty Obligations ..................................... .. 3 Regulatory Wastes ................... ............... ....... .. 4 Additional Releases . ................... .................. .... .. 5 Projected Plan of Operation-Water Year 1981 7 Upper Basin Reservoirs Fontenelle Reservoir. .. ............. .......... ....... ..... .. 8 Flaming Gorge Reservoir 10 Wayne N. Aspinall Unit-Blue Mesa, Morrow Point and Crystal Reservoirs 12 Navajo Reservoir ....... ...... ............................. 14 Lake Powell ..................................................16 Lower Basin Reservoirs Lake Mead 18 Lake Mohave 20 Lake Havasu 22 River Regulation ....................... ......................... 24 Flood Control. .......... ....................................... 25 Beneficial Consumptive Uses Upper Basin Uses and Losses 26 Lower Basin Uses and Losses 26 Water Quality Operations 28 Enhancement of Fish and Wildlife Upper Basin 29 Lower Basin 30 Preservation of Environment 31 Power Operations Upper Basin-Colorado River Storage Project 32 Generating Unit Maintenance 33 Lower Basin 34 Generating Unit Maintenance 3'5 1 Introduction Authority for Report Actual Operations Under Criteria-Water Year 1980 Navajo Dam and Reservoir Aerial of Fontenelle Dam Fontenelle Dam, Seedskadee Project, Wyoming The operation of the Colorado River Pursuant to the Colorado River Basin The operational plan for water year 1980 Basin during the past year and the pro­ Project Act (Public Law 90-537) of 1968, reflected the concept of Hoover storage jected operations for the current year I am pleased to present to the Congress, credits established during 1979. Prior to reflect domestic use, irrigation, hydro­ and to the Governors of the Colorado filling of Lake Powell in June 1980, anti­ electric power generation, flood control, River Basin States, the tenth annual cipatory releases from Lake Mead for water quality control, fish and wildlife report on the Operation of the Colorado flood control and river regulation pur­ propagation, recreation, and Colorado River Basin. This report describes the poses were accounted for as if actually River Compact requirements. actual operation of the reservoirs in the stored in Lake Mead. Scheduling a mini­ Colorado River drainage area constructed mum annual release of 8.23 million Storage and release of water from the under the authority of the Colorado River acre-feet from Lake Powell during fall of Upper Basin reservoirs are governed by Storage Project Act, the Boulder Canyon 1979 and winter of 1980 was planned on all applicable laws and agreements con­ Project Act, and the Boulder Canyon the basis that, under any reasonable cerning the Colorado River, including Project Adjustment Act during water year inflow conditions, the active storage of the impoundment and release of water in 1980 and the projected operation of Lake Powell would have been less than the Upper Basin required by Sec. 602(a) these reservoirs during water year 1981 theoretical storage of Lake Mead by of Public Law 90-537. The operation of under the "Criteria for Coordinated Long­ September 30, 1980. the Lower Basin reservoirs reflects Range Operation of Colorado River Mexican Treaty obligations and Lower Reservoirs," published in the Federal As it became apparent from updated Basin contractual commitments. Register June 10, 1970. forecasts that the inflow would be suffi­ cient, the scheduled releases were Nothing in this report is intended to James G. Watt, Secretary revised with the objectives of filling Lake interpret the provisions of the Colo­ U.S. Department of the Interior Powell while releasing water on a sched­ rado River Compact (45 Stat. 1057), the ule to optimize power production. Re­ Upper Colorado River Basin Compact leases from the other reservoirs were (63 Stat. 31), the Water Treaty of 1944 made to meet the mUltiple purpose with the United Mexican States (Treaty demands of the system including flood Series 994, 59 Stat. 1219), the decree control, water supply, power production, entered by the Supreme Court of the recreation, and fish and wildlife enhance­ United States in Arizona v. California, ment. et al. (376 U.S. 340), the Boulder Canyon Project Act (45 Stat. 1057), the Boulder Canyon Project Adjustment Act 54 Stat. 774; 43 U.S.C. 618a), the Colorado River Storage Project Act (70 Stat. 105; 43 U.S.C. 620), or the Colorado River Basin Project Act (82 Stat. 885; 43 U.S.C. 1501). Projected Plan of Operation Under Criteria-WaterYear 1981 Workers at Parker Dam During water year 1980, the water supply Determination of "602(a) Storage" eries under Sec. 602(a)(1) and (2) of in the Colorado River Basin was approxi­ Sec. 602(a)(3) of the Colorado River Public Law 90-537. mately 124 percent of the long-term Basin Project Act of September 30, 1968, average, ranging from 106 percent for the (Public Law 90-537), provides for the Taking into consideration these relevant Green River at Fontenelle Dam to 132 storage of Colorado River water not re­ factors, the Secretary has determined percent for the San Juan River at Navajo quired to be released under article III(c) that the active storage in Upper Basin Dam. Aggregate Colorado River System and III(d) of the Colorado River Compact reservoirs forecast for September 30, storage at the end of the water year was in Upper Basin reservoirs to the extent 1981, exceeds the "602(a) Storage" 54,512,000 acre-feet, representing an the Secretary fi nds it necessary to assure requirement under any reasonable range increase of 3,573,000 acre-feet from the Compact deliveries without impairment of assumptions which might be realis­ previous year. of annual consumptive uses in the Upper tically applied to those items which he is Basin. Article II of the "Criteria for Coor­ directed to consider in establishing this On June 22, 1980, Lake Powell filled to dinated Long-Range Operation of Colo­ storage requirement. Therefore, the capacity, terminating the filling criteria. rado River Reservoirs" provides that the accumulation of "602(a) Storage" is not On September 30, 1980, the active con­ annual plan of operation shall include a the criterion governing the release of tent of Lake Powell was 23,084,000 acre­ determination by the Secretary of the water during the current year. feet and the theoretical storage of Lake quantity of water considered necessary to Mead was 24,223,000 acre-feet (actual be in Upper Basin storage as of Septem­ storage was 23,637,000 acre-feet). ber 30 of the current year. This deter­ Mexican Treaty Obligations Releases from Lake Powell amounted to mination shall consider all applicable Annual calendar year schedules of 10,920,000 acre-feet. By the end of the laws and relevant factors including, but monthly deliveries of water in the limi­ water year, the goals of the 1980 opera­ not limited to the following: (a) historic trophe section of the Colorado River, tion plan for the major storage reservoirs streamflows; (b) the most critical period of allotted in accordance with the Mexican in the system had been achieved. record; (c) probabilities of water supply; Water Treaty signed in 1944, are formu­ (d) estimated future depletions in the lated by the Mexican Section and pre­ A description of the operations of each Upper Basin, including the effects of sented to the United States Section, reservoir in the Colorado River Basin recurrence of critical periods of water International Boundary and Water follows. Charts 1-8 show monthly outflow, supply; (e) the "Report of the Committee Commission, before the beginning of water surface elevation, and active on Probabilities and Test Studies to the each calendar year. storage in each reservoir during water Task Force on Operating Criteria for the year 1980. Colorado River," dated October 30, 1969, and such additional studies as the Secre­ tary deems necessary; (f) the necessity to assure that Upper Basin consumptive uses are not impaired because of failure to store sufficient water to assure deliv- 3 Upon 30 days' advance notice to the Of the 4,050,000 acre-feet of mainstream Regulatory Wastes United States Section, Mexico has the Colorado River water reaching the Deliveries to Mexico consist of river right to modify, within the total schedule, boundary, about 3,059,000 was delivered water delivered to Imperial Dam and any monthly quantity prescribed by the through Pilot Knob wasteway from the waste and drainage return flows from schedule by not more than 20 percent. All-American Canal. An estimated 750,000 water