Flathead Lake Discharge As a Function of Lake Elevation

Working for clean water, healthy ecosystems and lasting quality of life in the Flathead watershed in northwest Montana.

Effect of Lake Level on Outflow

The level of the lake determines the rate of outflow from it at Polson. Kerr Dam has a turbine capacity of approximately 15,000 cubic feet per second. As displayed by the graphs below, the outflow from the lake does not reach 15,000 cfs until the lake is approximately 2885.75. The curves were generated from data from the USGS gauge at Polson for 1 October 1929 through 30 September 1937, the most recent period before Kerr Dam began regulating outflow from the lake.