21-032 Dworshak Dam continues to refill as flow augmentation season approaches

Walla Walla District Corps of Engineers
Published June 4, 2021

AHSAHKA, Idaho –Dworshak Dam releases will remain at 1,600 cubic feet per second (cfs) as the reservoir continues to refill throughout the month. This operation is intended to capture as much water as possible before the start of flow augmentation.

Typically, flow augmentation begins between June 20 and July 10. However, the start of augmentation is dependent on regional water temperatures. Flow augmentation is intended to keep Lower Granite’s tailwater at or below 68 degrees Fahrenheit. Currently, Lower Granite’s tailwater is approximately 58.5 F, and the natural river temperatures in the Clearwater River at Orofino and in the Snake River at Anatone are approximately 51.5 F and 61.5 F respectively.

Analysis for river temperature forecasting and temperature monitoring will begin next week. Water managers will release another announcement regarding Dworshak operations before flow augmentation commences.

The rate of change in downstream river stage as measured at the United States Geological Survey (USGS) Clearwater River Near Peck, ID (gage #13341050) is not being impacted by Dworshak operations at this time.

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. 21-040