The Bureau of Reclamation has approved a record of decision requiring a long-term pattern of releases from 151.95-MW Flaming Gorge Dam that approximate a natural pattern of river flow and water temperature. BuRec said it will work with agencies and the public to reduce economic effects of the resulting power plant bypasses on the Green River in northeastern Utah.
BuRec’s Upper Colorado Regional Director Rick Gold signed the record of decision in February, implementing a proposal from a final environmental impact statement. The EIS examined strategies intended to help recover populations and protect habitat of four endangered fish species in the Green and Colorado River basins. It also would maintain all authorized purposes of the dam, part of the federal Colorado River Storage project.
The Upper Colorado River Endangered Fish Recovery Program published flow and temperature recommendations in 2000 for endangered fish downstream of Flaming Gorge. They form the basis of the action alternative that will be implemented by the record of decision. The EIS indicated there would be no significant adverse effects from implementing the recommendations, and that undesirable effects, if any, could be moderated or eliminated by adaptive management.
Under operating criteria established by BuRec in 1974, normal reservoir releases through Flaming Gorge power plant range from 800 to 4,600 cubic feet per second. Under the action alternative, releases now will be patterned so that recommended peak flows, durations, and base flows and temperatures for three reaches of the Green River would be achieved “to the extent possible.”
BuRec to refine management based on additional knowledge
BuRec said it intends to work with agencies and the public, through the Upper Colorado Endangered Fish Recovery Program, to address potential economic effects of power plant bypasses.
One particular flow recommendation — a spring peak release of at least 18,600 cfs in Reach 2 for two weeks or more in at least one of four average hydrological years — has the greatest potential for negatively affecting several resources, including power generation. However, the EIS determined considerable potential exists to further reduce undesirable effects through adaptive management, BuRec said.
Additional knowledge gained through the adaptive management process could be used to refine the recommendations to maintain or improve conditions for the endangered fish species while minimizing negative effects to the dam’s authorized purposes, BuRec added.
BuRec said it would: assess the possibility of improving connectivity of floodplain habitats; identify ways to improve entrainment of larval razorback suckers in those habitats; maintain the river channel; restore natural variability of the river system; and meet other goals of flow and temperature recommendations at lower peak flow levels where feasible.
Under the record of decision, normal power plant operations would continue to be adjusted on a daily basis to meet power system needs, BuRec said. Normal dam and power plant operations would be altered temporarily in response to emergencies involving dam safety, power system conditions, or the safety of people involved in activities on the river.