Construction on Outlet Dam resumes
A view of Priest River below Priest Lake's Outlet Bay Dam.
(Photo courtesy IDAHO DEPARTMENT OF WATER RESOURCES)
Staff Writer | December 1, 2023 1:00 AM
PRIEST LAKE — Construction on Priest Lake’s Outlet Dam resumed construction in October and will be undergoing renovations throughout the winter of 2023.
This project was put on hold last winter due to unexpected challenges but is expected to be completed in the coming months. The new construction will add the ability to raise the lake six inches higher if needed in drought conditions and will replace the "apron" on the downriver side of the dam to prevent scouring, which can destabilize the dam's foundation.
“This work is complex and requires fully dewatering part of the dam on the southeast side,” Lake Commission staff said in a press release.
Michelle Richman, Idaho Department of Water Resources regional manager, provided an early November construction update.
“Idaho Department of Water Resources is working with the construction company, Northbank Civil and Marine, to facilitate successful completion of the project,” she said.
Richman said the lake recently reached the .1-foot mark Nov. 1, and in the following two weeks, the department has partnered with construction workers to build a cofferdam — directing 100% of the river flow through a flume to allow a new concrete pad to be poured on the south side of the river. Because of this new flow pattern, the IDWR has reduced flow to roughly 100 cubic feet per second during the day to ensure safety for construction workers.
During non-construction hours, the department will operate gates to increase flow through the dam to 400 cfs or more, Richman said. Due to the rain and day-time gate closures, the lake is rising and is currently at .25 feet.
Richman said the department anticipates typical winter operations to resume by mid-November. More updates will be provided throughout the project. For questions on the Outlet Dam construction, contact Richman at firstname.lastname@example.org or 208-762-2800.