Unregulated inflow into Flaming Gorge Reservoir during the month of March was 77,000 acre-feet (AF), or 76 percent of average. The reservoir elevation is 6,025 feet. Observed inflows are averaging 2,200 cubic feet per second (cfs).
Flaming Gorge releases are currently 1,500 cfs daily release with hourly fluctuations for hydropower. Forecasts have decreased and releases are decreasing to 1,000 cfs on April 10, 2015 in order to obtain the May 1 reservoir elevation target of 6,027 feet.
Inflows for the next three months are projected to be below average: with April, May and June forecasted inflow volumes at 120,000 AF (90% of average), 160,000 AF (65% of average), and 240,000 AF (64% of average), respectively.
SPRING PEAK RELEASE
As in the last four years, Reclamation again will be involved in a cooperative experimental program (Larval Trigger Study Program or LTSP) 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 began sampling light traps in the middle Green River yesterday, Monday, May 4, to determine the initial presence this year. The U.S. Fish and Wildlife Service (FWS) will be regularly sampling for larval Razorback Sucker and data will be processed and shared when available. Upon detection of larval presence, Reclamation will increase releases from Flaming Gorge in an effort to entrain larvae in backwaters where they have a better chance of survival. Reclamation anticipates at least 3 days notification in the event larval presence is reported and Flaming Gorge Dam releases are increased. Reclamation will determine the appropriate level of releases from Flaming Gorge Dam to achieve the goals of the experimental program, and is planning on releasing above powerplant capacity (~4,600 cfs) to full bypass (8,600 cfs) to achieve those goals.
Kevin Bestgen, the scientific point of contact for prediction of larval emergence, shared the following information with Reclamation. “The best predictor of first presence of larvae is spring peak flow magnitude in the Yampa River. There is a definite temporal component to this as higher magnitude spring peaks occur later, and lower ones earlier. Whether flow is the actual driver or not is uncertain; I rather think it is not but it appears to be a useful metric for first presence prediction... The highest flow point … was 2011; that year the temperature model predicted first presence late, by 2 days. In 2012, the model predicted first presence within 2 days, but last year was somewhat late missing by 5 days because temps were fluctuating and cool.” Current estimate for larval emergence is May 16-21. Current observed streamflow on the Yampa River measured at Deerlodge is 6,140 cubic feet per second (cfs).
The Green River measured at Jensen, Utah flow is currently 6,690 cfs. The forecast for Yampa River at Deerlodge indicates flows are expected to reach between 8,000 and 9,000 cfs on May 8-9, Friday through Sunday. Flows at Jensen, Utah, are expected to reach between 9,500 and 10,500 cfs on Saturday and Sunday, May 9 and 10. Current projections are based upon the most recent precipitation forecast. The 2-3 day forecast is fairly certain and uncertainty increases beyond 3 days. Yampa River projections will be updated as the forecast certainty increases.
To view the most current reservoir elevation, content, inflow and release, click on: Flaming Gorge Reservoir Data.
WORKING GROUP MEETING
The next Flaming Gorge Working Group meeting is scheduled for August 27, 2015, at 11:00 a.m. to be held in the Utah Department of Natural Resources building in Vernal, Utah. 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. Meeting notes from past Working Group meetings are posted on the Working Group webpage. For more information on this group and these meetings please contact Heather Patno at 801-524-3883.
Updated May 5, 2015
Email comments/inquires to: ResourceMgr@usbr.gov