SANDPOINT — Bonner County's two main lakes — Pend Oreille and Priest — are set to begin their move to their winter pool levels.

The drawdown of Lake Pend Oreille will start Sept. 19 and the drawdown of Priest Lake will begin Oct. 10.

Lake Pend Oreille will be held above an elevation of 2,060 feet until a full draft begin Oct. 1, followed by a gradual draft until Nov. 15. Winter pool elevation needs to be reached by that date to ensure shoreline kokanee "are not left high and dry," Molly McCahon, Lakes Commission executive director, said in a press release.

"Kokanee are an important food source for threatened bull trout and many other species," McCahon said.

While not required, a winter pool elevation of 2,051 feet has been the norm for the past 10 years, allowing for 11.5 feet of stored water before it is lowered for flexible winter pool operations, McCahon said.

That operation allows the Bonneville Power Administration to generate power in the winter by raising the lake and then releasing that water.

"This is rarely needed, so it would be preferred that Lake Pend Oreille not be used as the dial for this infrequent operation," she said. "There are plenty of reservoirs on the Columbia River System less populated and less dependent on year-round water recreation."

At winter pool, McCahon said not only is scenic beauty lessened, there also is far less fish habitat, boat launches and docks are left high and dry, making access of the lake difficult for anglers and first responders alike.

While there was a time when the lake was held at 2,055 feet in the winter, McCahon said the last time that happened was in 2012.

For Lake Pend Oreille, the fall drawdown generally begins after Sept. 18 or the third Sunday of the month, whichever is later. On Priest Lake, the drawdown begins on Oct. 10. The stable summer lake elevation is generally reached in mid-June and held between 2062 feet and 2062.5 feet for recreation.

This year, the lake didn't reach summer elevation until July 3 due, in part, to a very late peak runoff, McCahon said.

"Lake Pend Oreille elevation is measured in Hope but elevations along the Pend Oreille River vary greatly from that gauge and when the dam gates are wide open, the Pend Oreille River can be many feet lower than what is measured in Hope," she added.

McCahon said the Pend Oreille River is one of the Columbia River's three tributaries, with flows forming a significant contribution to the entire Columbia River Basin.

"Because of this, there are numerous pressures on the waters in the Pend Oreille Basin and balancing all the desired uses is complex and challenging, said McCahon.

On Priest Lake, the Idaho Department of Water Resources will begin its fall drawdown on Oct. 10. Water flow to the Priest River will increase each day to achieve winter pool by lowering the lake three feet from its current full pool of 2,440 feet by Nov. 1.

"This will facilitate kokanee spawning and accommodate boat and dock winterizing needs along the shoreline," McCahon said.

The Lakes Commission was formed, in part, to advise state officials lake levels for Lake Pend Oreille. A natural lake, the lake was dammed in 1955 to hold and control the top 11.5 feet. That water is manipulated with certain restrictions for power generation, recreation, fish and wildlife, and flood control.