PPL starts draw-down of Flathead Lake

By ALEX STRICKLAND / Bigfork Eagle

Flathead Lake should be two full feet below full pool by month's end and five feet below pool by the end of December, according to Pacific Power and Light, the company that operates Kerr Dam.

The drawdown reflects PPL's attempt to help minimize shoreline erosion — especially along the wind-buffeted North Shore — as winter storms start to roll in.

The drawdown is taking place despite above average streamflows at the end of the summer, which were 110 percent of normal during September and 97 percent of normal so far in October, according to PPL.

The Lake is projected to be at 2,891 feet by Oct. 31 and to 2,888 feet by Dec. 31. The full pool elevation of Flathead lake is 2,893 feet and last winter reached a minimum height of 2,883.

Flathead Lake Biological Station scientist Mark Lorang explained to the Eagle last year that a drop of only a few feet can move breaking waves hundreds of yards offshore. Lorang explained that basic physics preclude a wave's height from exceeding about 80 percent of the water's depth, so the shallow North Shore sees the effects of the drop quickly.

Lorang called PPL's updated management of the lake and Flathead River downstream from Kerr Dam a "big, positive thing."

The gradual drawdown also prevents the need for large water releases in November and December, which, in the past, have adversely affected aquatic life in the river.