The process to lower Lake Koocanusa for flood risk management began this fall with water releases from Libby Dam, the U.S. Army Corps of Engineers announced.

The lake is being operated to be at or below a target elevation of 2,436 feet above sea level by the end of November while optimizing releases for power production. The operation is consistent with the ramping rates consulted on in the 2006 U.S. Fish and Wildlife Service Biological Opinion.

The Corps advises river users that conditions can change rapidly and should adjust river use plans accordingly. The project may increase flows as much as 10,000 cubic feet per second per day and decrease flows as much as 5,000 cfs per day.

The water level in the river below Libby Dam varies with the discharge rate. Local tributary inflow contributes a minimum amount to the Kootenai River flow volume in the late fall and winter.

The target elevation for end of December will be between 2,411 feet and 2,426.7 feet depending on the December water supply forecast. Lake Koocanusa elevation as of Nov. 18 was 2,439 feet.

Libby Dam is part of the Federal Columbia River Power System and serves multiple purposes for the region, including flood risk management, hydropower generation, recreation, and fish and wildlife. Power generated at Libby is marketed by Bonneville Power Administration.

For more information on flows, Lake Koocanusa and Kootenai River levels, call the Libby Dam automated recording at 293-3421.