AHSAHKA, Idaho – To give fish hatcheries an opportunity to release juvenile fish smolts, Dworshak Dam discharge flows will be reduced today, March 26, between about 11 a.m. and 1 p.m., from the current 14,000 cubic feet per second (cfs) to 8,500 cfs, according to U.S. Army Corps of Engineers officials. Reservoir managers plan to maintain the reduced flows through Monday, April 2.
The flow reduction will lower the downstream water surface elevation in the Clearwater River by about a foot, as measured at the USGS gage station near Peck, Idaho.
Fish hatchery managers at the Dworshak National Fish Hatchery and Clearwater Hatchery just below Dworshak Dam will release chinook and steelhead juvenile fish smolts into the river to begin their migration to the ocean. Dworshak Reservoir has ample space for flood risk management operations, should inflows increase during this period. Additional increases or decreases may be necessary as conditions change.
The Corps works with regional water managers, other agencies and tribes, and fish managers and hatcheries in joint efforts to keep total dissolved gasses below the Idaho State maximum threshold, when possible.
For safety, the public is advised to be aware of danger associated with fluctuating river flows and elevations. Outflow water is deep, cold and fast, so extreme caution should be used near river banks. 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 up or down in water elevation and volume of flow. Current Dworshak water-management conditions can be viewed on the Walla Walla District website at www.nwd-wc.usace.army.mil/nww/rreports.htm.
The dam has three Powerhouse units. This year, Dworshak Powerhouse Unit 3 is out of service and is unable to pass water from the reservoir until it goes back into service later this summer. The 220,000-kilowatt generator is capable of passing 5,600 cfs through the powerhouse. Units 1 and 2 combined pass 4,800 cfs. Water being passed through the Powerhouse units contain less total dissolved gasses than water spilled from higher up the dam.
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