Water release planned at Ririe Reservoir beginning Monday

The U.S. Bureau of Reclamation will increase flows from Ririe Reservoir into Willow Creek beginning Monday. The water release was ordered to meet required flood control obligations identified in a Ririe Dam winter storage study completed in 2015. Ririe Dam is located about 15 miles northeast of Idaho Falls and 4 miles south of Ririe. An initial release from Ririe of 150 cubic feet per second will fill the Willow Creek channel from the dam to the headworks structure located just upstream from the U.S. Highway 26 bridge. Flows will increase to 300 cfs Feb. 7 and again to 400 cfs the following day. Releases from Ririe will end Feb. 10, once the reservoir is drawn down to its required winter level. According to the Bureau, reservoir level and winter precipitation on the Willow Creek watershed are higher than they were in 2011, which was an “above-normal” snowpack winter. The reservoir exceeded its maximum winter content earlier this year than previous years. Water managers said the water release is needed to maintain the required flood control space in the reservoir. Several agencies will monitor the release including the Bureau of Reclamation, Water District 1, the U.S. Geological Survey, Progressive Irrigation District, and Mitigation Inc. Water has been released from the reservoir in February in only 4 other years, 1986, 1997, 2011, and 2013. Ririe Dam was completed in 1977 by the U.S. Army Corps of Engineers and is owned and operated by Reclamation. The reservoir has a capacity of 90,500 acre-feet, including 80,500 acre-feet for irrigation, flood control, and recreation, and 10,000 acre-feet reserved exclusively for flood control. River and reservoir data are available here.