9305

• UCREFRP Catalog Number: 9305
• Author: U.S. Fish and Wildlife Service.
• Title: Final Biological Opinion for the Operation of Flaming Gorge Dam.
• USFW Year: 1992.
• USFW - Doc Type: Denver, CO.
• Copyright Material: NO

4
the current and proposed operation of Flaming Gorge Dam °is not likely to
affect the continued existence of the bald eagle, peregrine falcon, or Ute
ladies'-tresses orchid.
DESCRIPTION OF FLAMING 60R6E ~PERATIflN
BACKGROUND
Flaming Gorge Dam, located on the Green River in northeastern Utah, lies
approximately 410 river miles upstream from the confluence of the Colorado and
Green Rivers. The reservoir extends north ini;o Wyoming with its upper
terminus near the town of Green River, Wyoming. At capacity, the reservoir
has 42,000 surface acres, is 91 miles long, and has .a live storage capacity of
3.75 million acre-feet. Flaming Gorge Dam was authorized by the Colorado
River Storage Project Act of 1956, 43 U.S.C. 620. The operation of the
Colorado River Basin projects, which includes Flaming Gorge, was further
described in the Colorado River Basin Project Act of 1968, 43 U.S.C 1502,
which states:
"This program is declared to be for the purpose, among others, of
regulating the flow of the Colorado River; controlling-floods;
improving navigation; providing for the storage and delivery of the
waters of the Colorado River for reclamation of lands, including
supplemental water supplies, and for municipal, industrial, and
other beneficial purposes; improving water quality; providing for
basic public outdoor recreation facilities; improving conditions for
fish and wildlife, and the generation and sale of electrical power
as an incident of the foregoing purposes."
Construction of the dam and powerplant began in 1956 and-was completed in
1964. Filling of the reservoir began in November 1962 and continued through
1966. Full operation of the facility began in 1967. Reservoir releases
through the powerplant range from 800 to 4,700 cubic feet per second (cfs).
Maximum powerplant releases are constrained by generator output and reservoir
elevation; while minimum releases are constrained by an agreement with the
Utah Division of Wildlife Resources which provides for a minimum flow of
800 cfs to maintain the tailwater trout fishery. Additionally, the dam has
the capacity to release up to 4,000 cfs through two river outlets (jet tubes)
and an additional 28,800 cfs through the spillway.
OPERATION
Existing and proposed future operational criteria for Flaming Gorge Dam and
reservoir provide for a full reservoir while maximizing power revenue and
avoiding the use of the jet tubes and/or spillway. Depending on snowpack and
monthly forecasting, an appropriate winter drawdown to avoid spills results in
minimum reservoir storage of approximately 800,000 acre-feet at 6,020 feet in
elevation which usually occurs in March. Attempts are made to refill the
reservoir during spring runoff, and maximum levels usually occur in July.
Releases during the remainder of the year are patterned to meet energy
demands. Peak electrical power demand occurs during summer (July through