Turbidity and suspended sediment concentrations may be higher than normal in the Shoshone River downstream of Willwood Dam between approximately October 18th and November 5th as the Willwood Irrigation District lowers the water level behind the dam in preparation for winter operations. Lowering the water level is necessary to prevent damage to the canal gates that may occur with freezing temperatures. The late-October time-frame is consistent with the current Operating Recommendations for Willwood Dam and is intended to minimize potential impacts of sediment releases to the downstream fishery, particularly October 15th to November 15th, the fall spawning period for brown trout and mountain whitefish. The Willwood Irrigation District is coordinating the drawdown with Wyoming Department of Environmental Quality (WDEQ), Wyoming Game and Fish Department (WGFD), Wyoming Water Development Office, Wyoming State Engineer’s Office, United States Bureau of Reclamation, and the United States Geological Survey (USGS), so that researchers from the University of Wyoming, USGS, WGFD, and WDEQ can collect data during this period. The data will be used to inform future operations of Willwood Dam.
Questions regarding these efforts can be directed to David Waterstreet, Watershed Protection Program Manager, Water Quality Division, Wyoming Department of Environmental Quality, at David.Waterstreet@wyo.gov or 307-777-6709.