Idaho Power Company began its annual fall chinook salmon program on Monday to manage water releases from the Snake River’s Brownlee Dam to maintain a spawning flow below Hells Canyon Dam at 9,200-9,300 cubic feet per second.
Minimum flows below Hells Canyon Dam are maintained until the salmon “fry” emerge from eggs planted in redds (nests) by spawning salmon downstream of the dam. Hells Canyon is the farthest downstream of three IPC projects that make up the Hells Canyon Complex. The dams have, since their construction in the late 1950s and 1960s, blocked upstream passage of salmon and steelhead. The dams are located along the Idaho-Oregon border.
The current target date for ending the spawning flows is Dec. 10.
In addition to maintaining these flat flows, Idaho Power will begin aerial surveys of salmon spawning areas (redds) later this month.
The fall chinook program is part of Idaho Power’s commitment to protect and preserve the environment surrounding the company’s dams and generation facilities. To learn more, go to IPC’s web site at www.idahopower.com/fish.
As of Oct. 8, Brownlee reservoir’s elevation was 2,045 feet, or 32 feet below full. At that level, boat ramps at Hewitt and Woodhead parks are usable. Because the flat flows will be lower than the inflows coming into Brownlee, the reservoir level is expected to rise slowly over the coming weeks.
Brownlee is the uppermost of the three Hells Canyon Complex dams, and backs up the system’s largest water storage reservoir.
For updated Snake River flow and Brownlee elevation and boat ramp information, please visit our Idaho Power website, http://www.idahopower.com/OurEnvironment/WaterInformation.