22-042 Dworshak Dam to increase to 15,500 cubic feet per second as reservoir nears full

Walla Walla District U.S. Army Corps of Engineers
Published June 9, 2022
Dworshak Dam

Dworshak Dam

AHSAHKA, Idaho – Dworshak Dam will be increasing its outflow to 15,500 cubic feet per second (cfs) over the next two days. Currently, the dam is releasing approximately 9,600 cfs with a forebay elevation of 1,593 ft and 7 ft remaining until the project is full at 1,600 ft.

Dworshak is expected to reach full pool by June 20, but due to high inflow and the remaining snowpack, the outflow will be increased to refill the reservoir safely. Operations at Dworshak will change the height of the Clearwater River downstream of the dam by less than a foot, gradually, across a one-day period.

The current operation will result in total dissolved gas (TDG) above 110%. The additional outflow is expected to cause TDG to rise to 112-114%.  With this flood control operation, the Corps will continuously evaluate the basin conditions to determine the soonest and safest possible time to reduce the outflow to minimize the higher TDG. Currently, it is expected that the higher outflows will last for the next seven days. The Corps will continue to work with regional water managers, other agencies, tribes, 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.

The rate of change in downstream river stage limit of one foot per hour, as measured at the United States Geological Survey (USGS) Clearwater River Near Peck, ID (gage #13341050), will not be violated due to project operations.

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 flow volume. 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/.

Public Affairs Office

Release no. 22-042