t • I UNITED STATES DEPARTMENT OF THE INTERIOR BUREAU OF RECLAMATION 125 SCALE OF MILES Annual Report Operation of the Colorado· River Basin 1976 Projected Operations 1977 u.s. Department of the Interior Thomas S. Kleppe, Secretary Bureau of Reclamation Gilbert G. Stamm, Commissioner January 1977 Table·of Contents Introduction ii Authority for ·Report ii Actual .Operations under Criteria-Water Year 1976 1 Upper Basin Reservoirs 2 Lo~er Bas1nReservoirs __ ------------------------------~------------ 14 River Regulations 20 Beneficial Consumptive Uses 21 Upper Basin Uses 21 Lo~er Basin Uses and· Losses 21 Water Quality Control 22 Water Quality Operations during Water Year 1976 22 Enhancement of Fish and Wildlife 23 Upper Basin 23 Lo~erBasin 23 Preservation· of Environment 24 Projected Plan of Operation under Criteria for Current Year ~------------------------------------------__ 26 Determination Storage" 26 Lower Basin Requirements 27 Plan of Operation-Water Year 1977 29 Upper Basin Reservoirs 30 Lo~er Basin Reservoirs 31 (Prepared pursuant to the Colorado River Basin Project Act of 1968, Public Law 90-537) Intr cti The operation of the Colorado River Basin during the past year and the projected operation for the current year reflect domestic use, irrigation, hydro­ electric power generation, water quality control, fish and wi Idl ife propagation, recreation, flood control, and Colorado River Compact require­ ments. Storage and release of water from the Upper Basin reservoirs recognize all applicable laws and relevant factors governing the Colorado River, in­ cluding the impoundment of water in the Upper Basin required by section 602(a) of Public Law 90-537. The operation of the Lower Basin reser­ voirs reflects Mexican Treaty obligations and Lower Basin contractual commitments. ,eDort Winter sailing on Lake Mead, Pursuant to the Colorado River Basin Project Act Boulder Canyon Project, (Public Law 90-537) of 1968, I am pleased to pre­ Arizona-Nevada. sent to the Congress, and to the Governors of the Colorado River Basin States, the sixth Annual Re­ port on the Operation of the Colorado River Basin. This report describes the actual operation of the reservoirs in the Colorado River drainage area constructed under the authority of the Colorado River Storage Project Act, the Boulder Canyon Project Act, and the Boulder Canyon Project Ad­ justment Act during water year 1976 and the pro­ jected operation of these reservoirs during water year 1977 under the "Criteria for Coordinated Long-Range Operation of Colorado River Reser­ voirs," published in the Federal Register June 10, 1970. Thomas S. Kleppe, Secretary U.S. Department of the Interior Crystal Dam, Curecanti Unit, Colorado. ii Operation of the Colorado River during 1976 was based on a forecast of runoff. Starting January 1, the snowmelt runoff was forecast and the required release of stored water to meet demands was scheduled for each reservoir through September. At the beginning of each month thereafter through June, the forecast was r"evised based on precipita­ tion and snow data collected during the month and the scheduled operation was revised accord­ ingly. A description of the actual operation of each of the reservoirs in the Colorado River Basin follows. Charts 1 through 9 show hydrographs of monthly outflow from the reservoirs and water surface ele­ vation and active storage in the reservoirs for water year 1976. Water skiers, Blue Mesa Reservoir, Curecanti Unit, Colorado. Looking south from Imperial Dam, left to right, the California Sluiceway, All-American Canal, and the Desilting Basins, California. 1 Irs• Fontenelle Reservoir During the past year, Fontenelle Reservoir was operated for hydroelectric generation, flood con­ trol, fish and wildlife enhancement, and recreation. During the fall and winter of 1975-76, the reser­ voir water surface elevatiqn was reduced slowly from elevation 6,504 feet at the beginning of the water year to a low elevation of 6,480 feet prior to spring runoff in April. The minimum release I during the fall and winter was 700 cubic feet per j s8cond (fP/s) to generate power and maintain fish flows. Springtime releases were controlled to ~r-- allow the reservoir to fill early in August. Maxi­ Chart I mum releases of 7,500 fP/s from the reservoir STATISTICS occurred late in June. On September 30, 1976, the ACTIVE STORAGE* reservoir had 335,000 acre-feet of water inactive RESERVOIR (ACRE· ELEVATION FEET) (FEET) storage at elevation 6,505 feet. (Chart 1.) MAXIMUM STORAGE 344,834 6506 RATED HEAD 233,789 6491 MINIMUM POWER 194,962 6485 SURFACE AREA (FULL) 8058 ACRES RESERVOI R LENGTH (FULL) 18 MILES POWER PLANT NUMBER OF UNITS 1 TOTAL CAPACITY 10,000 KILOWATiS "does not include 563 acre feet of dead storage below 6408 feet OUTFLO\V UPPER QUARTILE 8 :W;E~~ AVERAGE •••••••••••• MOST ADVERSE ~ g: ~ ~ g: ~ ~ ~ g a: 'S A' 'S ~ « ~ 2 2 « (f)LlJ ............. "'- I I .. I Water Year 1976 -----.......f------- Water Year 1977 -----.......- Fontenelle Dam and Reservoir, Seedskadee Project, Wyoming. STORAGE 3 2 i= w W Ll. W ex: u q: 0 0 0 6 ~ I- Z w .25 I- :2 0 U w > ~ u ~ 0 3 Flaming Gorge Reservoir Flaming Gorge Reservoir is operated as part of the Colorado River Storage Project (CRSP) in ac­ cordance with governing compacts and laws to provide river regulation, optimum power produc­ tion, recreation opportunities, and fish and wild­ life benefits. On September 30, 1975, the water surface was at elevation 6,038 feet. The active storage was 3,650,000 acre-feet. Release for power production caused the reservoi r to recede 9 feet the fall and winter to elevation feet. The 1976 runoff above was 1 000 or 16 of the average. With this a seasonal reached at elevation feet with an active age acre-feet water. FEETl MAXIMUM STORAGE 3,749,000 6040 RATED HEAD 1,062,000 5946 POWER 233,000 5871 AREA (FULL} 42,020 ACRES~-- RESERVOI R (FULL) 91 Ml LES NUMBER OF UNITS 3 TOTAL CAPACITY 108,000 *does not include 40,000 acre feet of dead storage below 5740 feet OUTFLOW 4,.....----------------.;;;:;.:...;...=.:..;,.;;;:;p.:...;.:..:..;..:..=.~-1"""""'"'''''''''I''''''~!'''''''''''''-..-~i'''''''''''''.....,....- ..........--- 3 2 1 ~ 0 ~ ........................................--.........- ---- 8 4 """I""""'''''"''''f-..,-..:;".;;.;.---,...............,..-''Y''''''''"'........,.......;.....'''I''''''''''''''"'''''F-'''f''''''''''......,..............'1''''''''''''''''''''''!'''''~--. ~ 3 j:: ttl 2 u.. () co :::> () o o o 3 2 0 r-: :> u a:i u 0 I..U z I..U 0 Z 0 ~ u.. 4 o o o 0' ~ t­ Z w t­ oZ u w > i= u <t 5 Curecanti Unit-Blue Mesa Reservoir At the end of September 1975, Blue Mesa Reser­ voir had 695,000 acre-feet of active water storage, with a water surface elevation of 7,504 feet The reservoir was drawn down to elevation 7,468 feet, 60 percent of the long-time average. During April­ JUly 1976, inflow to Blue Mesa was 477,000 acre­ feet, with a 1976 water year total of 729,000 acre­ feet. The seasonal high water level for the reser­ voir was elevation 7,498 feet and an active storage of 645,000 acre-feet. During water year 1976, a mini­ mum flow of 200 ft3 /s was maintained below Gun­ nison Tunnel to protect the fishery. The March 1, 1976, forecast of the April-July 1976 inflow to Blue Mesa was 610,000 acre-feet. The flood control regulations did not require evacua­ tion of space during the snowmelt season; conse­ Chart 3/ Blue a quently~ the operation of Blue Mesa did not in­ Reservoir clude releases for flood control. (Chart 3.) STATISTICS From May 1 through September 30, 1976, con­ ACTIVE STORAGE* trolled releases from Blue Mesa provided down­ RESERVOIR (ACRE· ELEVATION FEET) (fEET) stream flows that were compatible with construc­ MAXIMUM STORAGE 829,523 7519 tion activities at the Crystal Dam site. RATED HEAD 249,395 7438 MINIMUM POWER 81,070 7393 SURFACE AREA (FULL) 9180 ACRES RESERVOIR LENGTH (FULL) 24 MILES POWER PLANT NUMBER OF UNITS 2 TOTAL CAPACITY OF UNITS· 60,000 KILOWATTS *does not include 111,232 acre feet of dead storage below 7358 feet OUTFLOW UPPE R QUARTI LE 4 3 2 a z 0 0 u 4 w en 3 ~ w w 2 u. u 1 iii ~ u 0 0 4 0 0 3 en w 2 «en w 1 ....J W a:: 0 14 3 2 1 0 ~ :> u a::i ci ci >- u 0 UJ z w « 0... « 0 z 0 ~ u. ~ « ~ Water Year 1976 6 Blue Mesa Dam, Curecanti Unit, Colorado River Storage Project, Colorado. STORAGE -8 6 4 t= w w u.. 2 W ex: «u 0 0 0 0- 0 ~ I- Z w I- 2: 0 U w > j: «u 7 228-381 0 - 77 - 2 Curecanti Unit-Morrow Point Reservoir Morrow Point Reservoir was essentially full dur­ ing water year 1976. On September 30, 1975, the reservoir contained 116,000 acre-feet of active storage at a water-surface elevation of 7,158 feet. Its inflow is extensively controlled by the operation of Blue Mesa Reservoir, which is upstream. Usually, Morrow Point Reservoir will be operated at or near full capacity regardless of the amount of snowmelt runoff. (Chart 4.) STATISTICS ACTIVE STORAGE* RESERVOIR ELEVATION (FEET) MAXIMUM STORAGE 117,025 7160 RATED HEAD 79,805 7108 MINIMUM POWER 74,905 7100 SURFACE AREA (FULL) 817 ACRES RESERVOIR LENGTH (FULL) 11 MILES POWER PLANT NUMBER OF UNITS TOTAL CAPACITY OF UNITS 120,000 KILOWATTS *does not include the 165 acre feet of dead storage below 6808 feet OUTFLOW 4 ,...... ........ -_U,:;;:.:P:..:.P,.:;.E:..:.R.;;;::QFU~A:..:.RT.;..:I,.:;.L:;;.E 0:--....,..............,........,...-"1'"""""""-......-......-...........- .........--- 3 2 0 0 Z 0 4 (J w CJ) 3 j:: w 2 w u. (J a:J :::> 0 () 0 4 0 ~ 3 CJ) 2 w CJ) <3: 1 w ..J Wa: 0 4 3 2 1 0 ;; UJ >- cj ;; r..: u z cD Z ....J c.: r..: u z u 0 UJ L' :::> UJ u 0 UJ 0 Z 0 ~ L- ;; ;; « 0 z 0 ~ I- (/).