IDAHO DEPARTMENT OF WATER RESOURCES
Summer Operations
As you are likely aware, construction of the Priest Lake Outlet Dam was complete as of Spring of 2024. One related modification at the dam included a six inch gate height increase to all eleven gates that makes it physically possible to hold the lake level at 3.5 feet during the recreation season. (This gate height modification was actually completed in Spring of 2022.)
Idaho Code 70-507 was updated in 2018 to establish how the lake level will be maintained throughout the recreation season as follows, depending on the anticipated type of water year:
- lake level to be held between 3.0 and 3.5 feet in dry and marginally dry years, and
- lake level to be held at 3.0 feet in wet to normal years.
The dam modifications and corresponding statute revisions were developed to avoid a repeat of the summer of 2015, in which drought led to extreme conditions. That summer, to maintain the required minimum lake level of 3.0 feet, the flow to Priest River below the dam was reduced to 42 cfs.
Stakeholders found such low flow in the Priest River unacceptable. The solution to prevent similar low flow in the Priest River in dry years is to maintain a higher lake level during the recreational season. In other words, keeping lake levels higher earlier in summer facilitates preservation of higher flow in the Priest River throughout the summer.
The increased gate height has been in place for three years now, and the Department is still developing best practices. As you are aware, weather and environmental conditions vary significantly from year to year at Priest Lake, and the operations need to accommodate the variation. The Department invites feedback to help inform future operations, planning, and development of best practices for managing the additional lake level in dry to marginally dry years. Helpful information would include photos with dates. Please email those to northerninfo@idwr.idaho.gov.
Fall 2024 Release
As for the Fall release of Priest Lake, lowering of the lake below 3.0 feet will begin on October 1,
2024. Please plan accordingly.
Please direct any questions or comments to
northerninfo@idwr.idaho.gov or call 208-762-2800.
Photo Pecky Cox
