The summer recreation level of Priest Lake is around 2,437.70 feet above sea level. The lake levels are controlled by Outlet Dam which is managed by the Idaho Department of Water Resources.
The summer level is typically reached in mid June, but can vary depending on snow pack, mountain temps, and precipitation. The lake is managed primarily for spring flooding and recreation. In early October the water is dropped about three feet to get it down to winter elevation before Kokanee begin spawning. The water is held down for flood control until water flows have slowed and then it is raised to the summer elevation.
The low snowpack, hot temperatures, low humidity, and lack of precipitation made for a stressful 2015 for Priest Lake. Early in July of 2015, it became apparent that it might become difficult to hold the lake to the typical summer pool. There were fears that all flows from the lake would need to be shut down into the river in the attempt of maintaining the summer pool. Flows to the river did get very low, but luckily they never needed to be stopped completely. This predicament did reveal issues that will need to be remedied in the future management of Priest Lake. The Idaho Department of Water Resources received $300,000 to invest in a number of studies in the Priest watershed. The initial study will evaluate the condition of the dam structure and the possibility of altering the structure. The second study will evaluate possible impacts around the lake from extra water being held back in anticipation of drought conditions. The third study will evaluate how to best replace the Priest Lake Thorofare breakwater structure to best keep the channel open to motorized traffic while also limiting the need for continued dredging. There will be a number of public meetings at Priest Lake on these studies over the course of the summer.