AHSAHKA, Idaho – In order to meet flood control targets for March and April, Dworshak Dam will be increasing releases starting Sunday Feb. 28 at 7 p.m.. This increase will result in the river rising approximately 3.5 feet between 7 p.m. Sunday night and 1 a.m. Monday morning.
The rate of change in downstream river stage will be limited to below one foot per hour as measured at the United States Geologic Survey (USGS) Clearwater River Near Peck, ID (gage #13341050).
The above average snowpack, which largely accumulated in the latter half of Feb., has prompted an increase in releases from Dworshak Dam and Reservoir near Orofino, Idaho. The current reservoir discharge of 4,200 cubic feet per second (cfs) will increase beginning Sunday, Feb. 28 at 7 p.m.. Discharge will rise Sunday night through the early hours of Monday morning to a total flow of 15,000 cfs. The release will be held constant at 15,000 cfs from Monday, March 1 through Friday, March 5. Roughly 10,500 cfs will be released through the powerhouse at its maximum capacity, and the remainder will be released through the spillway.
The Corps works with regional water managers, other agencies, tribes, and fish managers and hatcheries in joint efforts to keep total dissolved gas (TDG) below the Idaho State maximum threshold of 110%, when possible. However, spill from Dworshak will cause the TDG below the dam to be in the approximate range of 110% to 118%. The planned operation in the first week of March is intended to provide flexibility in reducing the risk of TDG rising above 110% at the end of March and beginning of April when hatchery releases are scheduled. The forecasted runoff for the North Fork of the Clearwater basin will be continuously revaluated for the opportunity to reduce TDG while still meeting flood control targets for both March and April.
For safety, the public is advised to be aware of the danger associated with fluctuating river flows and elevations. The river at this time of year is deep, cold and fast, so extreme caution should be used near riverbanks. Boaters, anglers and other people using waterways both in Dworshak Reservoir and below the dam on the Clearwater River are advised to be alert to changes in water elevation and volume of flow. Current Dworshak water-management conditions can be viewed on the Walla Walla District website at https://www.nwd.usace.army.mil/CRWM/Water-Control-Data/Project-Data/.
Release no. 21-005