Unregulated inflow into Flaming Gorge Reservoir during the month of April was 68,700 acre-feet (af), or 63 percent of average. Flaming Gorge Dam is releasing at a steady minimum release rate of approximately 820 cubic feet per second (cfs). Observed inflows are about 1,025 cfs. The reservoir elevation is 6020.57 feet and increasing. Forecasts remain below average and Flaming Gorge Dam is in the moderately dry hydrologic classification as outlined in the February 2006 Record of Decision - Operation of Flaming Gorge Dam Final Environmental Impact Statement.
The Colorado Basin River Forecast Center has issued the official May water supply forecast for the April through July unregulated inflow volume which is 480,000 af or 49 percent of the 1981-2010 thirty-year average. The spring hydrologic classification is officially in the moderately dry classification. Snowpack continues to be below average in both basins and spring weather has large impacts on runoff. Additionally, timing of the Yampa River spring peak flows and emergence of larval razor fish may not occur simultaneously, as evidenced by larval presence historically occurring as the Yampa River decreases to base flows. At this time, Reclamation is recommending operating conservatively and continuing to exercise the flexibility in the Record of Decision to operate one classification lower than indicated in the Flow Recommendations while being prepared to adjust if conditions warrant. Reclamation is currently operating in the dry hydrologic classification.
MAY RELEASES AND OPERATIONS
Flaming Gorge Dam is currently releasing the steady minimum release rate of approximately 820 cfs and will continue until further notification.
To view the most current reservoir elevation, content, inflow and release, click on: Flaming Gorge Reservoir Data.
SPRING PEAK RELEASE
Reclamation will be involved in a cooperative experimental program this year where the capture of endangered larval razorback sucker is the “trigger” to increase releases from Flaming Gorge Dam this spring. Reclamation plans to coordinate with scientists involved in real-time monitoring on the river to determine the first appearance of larval razorback sucker. Biologists will begin sampling light traps on May 13 in the middle Green River to determine the initial presence this year. Reclamation anticipates at least 2 days notification in the event larval presence is reported and Flaming Gorge Dam releases are increased.
Historically, biologists see larvae in the Green River during or after the Yampa Peak. Once larval presence has been detected, Reclamation plans to determine if releases from Flaming Gorge Dam combined with Yampa River flows below the confluence with the Green would entrain larval fish and meet the experimental flow target for one to six days above 8,300 cfs measured at the Green River at Jensen, Utah. Reclamation will determine the appropriate level of releases from Flaming Gorge Dam to achieve the goals of the experimental program, and may release above powerplant capacity (~4,600 cfs) to achieve those goals.
Current observed streamflow on the Yampa River measured at Deerlodge is 4,710 cubic feet per second (cfs). The Green River measured at Jensen, Utah flow is currently 5,400 cfs. The forecast for Yampa River at Deerlodge indicates flows are decreasing and expected to reach below 5,000 cfs on May 24rd with a rise to around 7,300 cfs by Memorial Day, May 27, 2013. Flows at Jensen, Utah are expected to decrease below 5,600 cfs on May 24 before increasing to approximately 8,000 cfs by May 27, 2013. Current weather models indicate warmer and drier conditions through Memorial Day. The predicted warmer temperatures will likely sustain Yampa River flows at Deerlodge between 6,500-7,500 cfs through the middle of next week and then decrease to current levels. Forecast uncertainty increases beyond 5 days and the magnitude of flows is highly uncertain.
Biologists with the US Fish and Wildlife Service began sampling light traps on Monday, May 13th, in the middle Green River to determine the initial presence this year. Larvae have not been reported in the system and biologists currently predict seeing larvae in the system next week at the earliest. The biologists will inform Reclamation once larval presence has been detected. Reclamation anticipates at least 2 days notification in the event larval presence is reported and Flaming Gorge Dam releases are increased. Communication will continue with updates on larval razorback sampling efforts and forecasted Yampa River flows.
Current projections of the daily release from Flaming Gorge for the period following the spring peak are for continued steady releases of approximately 820 cfs through the winter. Projected releases are provisional and subject to change.
WORKING GROUP MEETING
The next Flaming Gorge Working Group meeting is scheduled for August 21, 2013, at 11:00 a.m. at the new Utah Department of Natural Resources building in Vernal, Utah, located at 318 North Vernal Avenue. The Flaming Gorge Working Group is an open public forum for information exchange between Reclamation and the stake holders of Flaming Gorge Dam. The public is encouraged to attend and comment on the operations and plans presented by Reclamation at these meetings. For more information on this group and these meetings please contact Ed Vidmar at 801-379-1182.
The April 24, 2013 Flaming Gorge Working Group summary has been posted online and can be accessed on the Working Group pages.
Updated May 24, 2013
Heather E. Hermansen
Email comments/inquires to: ResourceMgr@usbr.gov