Avista Utilities plans to start its annual drawdown of Lake Coeur d'Alene in northern Idaho on Tuesday.

The Coeur d'Alene Press reports that the lake will gradually be lowered about a foot from full pool by the end of September.

Avista says the lake will be lowered an additional 1.5 feet per month after that until reaching its winter level.

Avista's Spokane River hydroelectric project includes Post Falls Dam. Its license from the Federal Energy Regulatory Commission requires Avista to maintain the level of the lake at the summer full-pool elevation of 2,128 feet from spring until after Labor Day.