Lake Management

Fall 2023:

On October 1, 2023, IDWR will begin releasing the lake level at Priest Lake below 3.0 feet. This will allow construction to resume at the Priest Lake Outlet Dam this Fall/Winter. The primary construction efforts will take place on the south side of the dam and include extension of the downstream concrete pad and the addition of boulders downstream of the dam for added scour protection.

Drawdown gate operations will lead to flow increases in the Priest River that will range between 100 and 400 cubic feet per second (cfs) at a time. To enable the construction crew to begin work as soon as possible, three operations will occur daily between October 1 and October 5. Those three operations each day will cumulatively result in daily increases of less than 1000 cfs for the day. The lake level will likely drop to 2.0 feet prior to October 8. The lake level will continue through the remainder of October to decline to the winter lake level.

Please stay clear of the dam to avoid fast-moving water both upstream and downstream of the dam for your safety.

For questions contact Michelle Richman, IDWR Northern Regional Manager, northerninfo@idwr.idaho.gov or (208) 762-2800.

May 15, 2023:

May’s warm temperatures melted much of the snow in the Priest Lake basin. Priest Lake levels peaked once last week and could peak again as snow continues to melt.

As of today, the lake level is 4.21 feet (ft), with and flow through the dam is 5360 cubic feet per second (cfs). Department staff continue to watch two SNOTEL sites, Bunchgrass Meadow and Hidden Lake, both at an elevation of about 5000 ft. The general rule of thumb is peak flow into Priest Lake occurs when the Hidden Lake site has about 75% melt-out and when the Bunchgrass Meadow site has about 60% melt-out. These melt-out conditions (75% and 60%) are approaching with the warmer temperatures. Below are links to the SNOTEL charts for both the Bunchgrass Meadow and Hidden Lake sites.

Bunchgrass Meadow:  AWS Plot (usda.gov)
Hidden Lake:  AWS Plot (usda.gov)

Once peak inflow and a corresponding peak lake level occur, the gates will be operated to maintain the lake level for summer recreation. The Department’s hydrologists are predicting a dry year, and the Department will aim to stabilize the lake level at 3.2 to 3.3 ft through the summer months.

For questions contact Michelle Richman, IDWR Northern Regional Manager, northerninfo@idwr.idaho.gov or (208) 762-2800.

April 2023:

As of early April, rain and warmer temperatures have led to rising water levels in Priest Lake. IDWR staff are watching two SNOTEL sites, Bunchgrass Meadow and Hidden Lake. Both sites are at an elevation of about 5000 feet and may receive more snow this season before a reduction in snow occurs. It is difficult to know when peak flow will occur each year. The general rule of thumb is that peak flow into Priest Lake occurs when the Hidden Lake site has about 75% melt-out and when the Bunchgrass Meadow site has about 60% melt-out. Below are the links to the SNOTEL charts for both sites.

Bunchgrass Meadow:  AWS Plot (usda.gov)
Hidden Lake:  AWS Plot (usda.gov)

Snow is presently melting at lower elevations in the Priest Lake Basin. As snow continues to melt and the Priest Lake water level steadily rises, the outlet dam gates will be managed to pass some runoff through the dam. The Department’s goal is to have the lake level at 3 feet by Memorial Day Weekend. Keep in mind that peak lake level and timing of the peak lake level is determined by Mother Nature.

The Department’s hydrologists are seeing preliminary predictions for a dry year; however, that could change if the Priest River Basin continues to receive precipitation. If this is a dry year, the Department will likely aim to hold the lake around 3.2 feet once the lake level is stabilized.

For questions contact Michelle Richman, IDWR Northern Regional Manager, northerninfo@idwr.idaho.gov or (208) 762-2800.

September 2022:

IDWR will begin drawing down Priest Lake on October 10th this year.  Flows through the Outlet Dam will increase daily to achieve the winter lake level by November 1.  This will facilitate kokanee spawning and accommodate boat and dock winterizing needs along the shoreline.  Construction and hydrologic conditions vary annually, which guide the operation decisions.  This winter, construction work on the dam will not take place other than on-site surveying.  Construction is anticipated to resume next October of 2023.

For questions contact Michelle Richman, IDWR Northern Regional Manager, northerninfo@idwr.idaho.gov or (208) 762-2800.