Dam Operations Designed to Benefit Fisheries, Hydropower, and Flood Management in Columbia River Tributaries, the Flathead and Kootenai Subbasins, Montana

Pacific Northwest agencies and tribes analyzed alternative strategies for operating the Federal Columbia River Power System (FCRPS), which culminated in a recommendation to the U.S. Department of State regarding the future of the Columbia River Treaty between Canada and the United States. Computer models examined the consequences of various operating strategies for ecosystem functions, flood management, and hydropower generation. This presentation focuses on an operating strategy that was fully implemented in 2009 in the Flathead and Kootenai subbasins in northwestern Montana, with applications for the entire Columbia River Basin. Computer models of each reservoir and river were used to assess alternative operating strategies and beneficial results were combined in successive iterations. Montana recommended additional refinements to Libby Dam and Hungry Horse Dam operations that are mutually beneficial to both countries. Specific recommendations include an improved “variable flow” flood management strategy (VarQ) designed to minimize reservoir drawdown for flood management, improve annual refill, and restore more natural river flows downstream of the federal dams. The “Montana operation” also provides flows for ESA-listed Kootenai white sturgeon (endangered) and bull trout (threatened). Systemwide improvements can be achieved by developing VarQ operations for additional storage reservoirs and coordinating operations among wet and dry subbasins.