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Title image: UC Region Colorado River Storage Project

Flaming Gorge Dam Operations

Flaming Gorge Dam is a water storage unit of the Colorado River Storage Project (CRSP).  The CRSP was authorized on April 11, 1956 to regulate the flow of the Colorado River; provide for flood control; provide for storage and delivery of water for irrigation, municipal, industrial, and other beneficial purposes; and generate electrical power. The CRSP also provides for recreation and improves conditions for fish and wildlife. Construction of the CRSP ater storage facilities, including Flaming Gorge Dam, was critical to the development of the Upper Colorado River Basin’s water and power resources.

Flaming Gorge Dam and Powerplant were constructed by the Bureau of Reclamation and were dedicated in 1964. The powerplant consists of three hydroelectric generating units with a combined capacity of about 151 megawatts and is part of the CRSP power resources. The capacity of the generating units has been increased from the original capacity through the application of new technology and other worked performed in the powerplant as repair or replacement of equipment occurred due to normal “wear and tear” and aging. For the period between 1964 and 2006 the average annual generation from the powerplant was 497,129,000 kilowatt-hours which is enough electricity to supply the annual needs of about 50,000 households. Operation and maintenance of the dam and powerplant are performed by employees of the Flaming Gorge Field Division of the Power Office and are funded from revenues received from the sale of CRSP power.

The initial operation of Flaming Gorge Dam focused primarily on regulating the flow of the Green River and generating hydroelectric power.  However, the storage and use of water altered natural flow patterns, water temperatures, and water quality of the Green River. While non-native fish (trout) populations downstream of the dam flourished, native fish populations and their habitat were modified or adversely affected in part by construction and subsequent operation of the dam. Except for high flows in the springtime to encourage geese to nest at high ground, there were no environmental constraints on water storage and power generation. Generally, downstream releases fluctuated to meet power demands. In 1974, a 400 cubic-feet per second minimum release was established; but under normal conditions a minimum release of 800 cubic-feet per second was implemented to improve the tailwater trout fishery and boating. In 1977 and 1978, the dam was retrofitted with a selective withdrawal structure to increase water temperatures for the tailwater trout fishery.

Under the Endangered Species Act of 1973, operations began to change to accommodate endangered fish research and recovery efforts. In 1985, an interim flow agreement was established between Reclamation and the U.S. Fish and Wildlife Service (Service) to change releases from the dam to protect critical nursery habitats for endangered fishes in the Green River downstream from Jensen, Utah. In general, flows became more stable with less fluctuation to meet power demands. Along with these changes, numerous research releases took place to support preparation of the Final Biological Opinion on the Operation of Flaming Gorge Dam which was issued by the Service on November 25, 1992. The opinion stated that the operation of Flaming Gorge Dam at that time was likely to jeopardize the continued existence of the endangered fish in the Green River and outlined elements of a Reasonable and Prudent Alternative that would offset jeopardy to the endangered fishes.

photo: Green River downstream, Browns Park
Green River downstream, Browns Park

In 1993, Reclamation began making releases from the dam in an attempt to meet the flow and temperature recommendations outlined in the 1992 Biological Opinion issued by the Service. These recommendations were based on the most current scientific data available at that time. One of the actions identified in the opinion was to collect more information about the flow and temperature needs of the endangered fishes to refine or modify the recommendations in the 1992 opinion. A five-year research study began in 1992 resulting in additional data and flow and temperature  refinements that were included in the 2000 Flow and Temperature Recommendations published by the Upper Colorado River Endangered Fish Recovery Program (Recovery Program). Established in 1987, the Recovery Program is a cooperative effort among the states of Utah, Colorado, and Wyoming, environmental and water user organizations, federal agencies including the National Park Service, Reclamation, Service, and Western Area Power Administration (Western), and the Colorado River Energy Distributors Association.

Under the National Environmental Policy Act, Reclamation undertook preparation of an environmental impact statement (EIS) on the operation of Flaming Gorge Dam in 2000 to describe the effects of operating the dam to achieve the temperature and flows specified in the Recovery Program’s September 2000 Flow and Temperature Recommendations, and to comply with Section 7 of the Endangered Species Act. The EIS was completed in November 2005 and the Record of Decision (ROD) was signed February 16, 2006. Implementation of the ROD began with the spring 2006 runoff season. 

The operational changes made to accommodate the flow recommendations, beginning with the 1992 Biological Opinion and followed by the ROD in 2006, have impacted power generation at Flaming Gorge Dam by reducing flexibility and changing generation patterns. Water that bypasses the powerplant cannot generate power resulting in a loss in revenues. Water moved from the summer and winter peak power demand seasons to provide high spring flows for the endangered fishes may necessitate increased generation from coal or other non-hydro generation resources and could have other cost and environmental impacts. The capacity of the powerplant and load following is restricted except for response to power system emergencies.

A Flaming Gorge Technical Work Group was established by the ROD in 2006 consisting of biologists and hydrologists from the Service, Western, and Reclamation. Its objective is to consider flow requests from the Recovery Program and provide proposals to Reclamation for flow and temperature regimes to best achieve ROD objectives for the endangered fish based on current year hydrologic conditions.

The Flaming Gorge Working Group, formed in 1993, meets three times a year to provide a forum for information exchange and for public or special interest groups to express their views on the operation of Flaming Gorge Dam. Information from the Flaming Gorge Technical Work Group and Recovery Program is also available to the Flaming Gorge Working Group. Reclamation considers input from the Flaming Gorge Working Group in its decision to operate Flaming Gorge to best achieve ROD objectives for the endangered fish consistent with CRSP purposes.


Last updated: November 25, 2008