21-022 Dworshak Dam discharges to decrease to minimum flow of 1,600 cfs by April 21

Published April 16, 2021

AHSAHKA, Idaho –Dworshak Dam will be decreasing releases from 7,800 cubic feet per second (cfs) to 1,600 cfs to conserve water for refill. Decreases begin today, April 16, and finish Wednesday, April 21. Fluctuations (up and down) in river flow will be observed April 20 during unit testing. Due to an increase in natural flows, the decreases in Dworshak flows on April 16-19 and 21 are expected to have a minimal impact on water levels.

Decreases on April 16 and 17 will occur steadily throughout the day, ending with flows of 5,900 cfs and 4,500 cfs respectively. Flows on April 18 and 19 will be held constant at 4,500 cfs. Unit testing, scheduled for April 20, will cause fluctuations up and down in the river throughout the day. A minimum of 4,500 cfs will be released throughout the day from midnight to 4 p.m. during unit testing, after which time releases will further decrease to 2,600 cfs by midnight. Releases will reach their lowest by 2 a.m. April 21, at 1,600 cfs. Releases are expected to remain constant 1,600 cfs at least through April 23. Reservoir releases will continue to be adjusted throughout the month of April to meet flood control targets and control refill.

The rate of change in downstream river stage will be limited to below one foot per hour as measured at the United States Geological Survey (USGS) Clearwater River Near Peck, ID (gage #13341050).

The current operation will result in total dissolved gas (TDG) remaining below 110%. The Corps will continue to work with regional water managers, other agencies, tribes, and fish managers and hatcheries in joint efforts to meet reservoir objectives and keep total dissolved gas (TDG) below the Idaho State maximum threshold of 110%, when possible.

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. 21-022