Priest Lake breakwater, Thorofare projects praised

By STEVE STUEBNER

Contributing Writer

COOLIN — Area residents had nothing but praise for the new 1,500-foot breakwater and deepening of the Thorofare channel during the Idaho Water Resource Board meeting last week.

Steve Klatt, director of the Bonner County Road and Bridge Department, and Priest Lake residents thanked board members for working with the community to build a new breakwater and dredging of the Thorofare channel in the winter of 2020-21. Extending the height of the Priest Lake outlet dam gates by 6 inches will occur in winter 2021-22 to complete the $5 million Priest Lake Water Management Project.

The total cost of the project was funded by the Idaho Legislature along with a $250,000 contribution in local matching funds.

“This really was a fine, fine project — thank you sincerely,” Klatt told board members during a business meeting last week in Coolin.

In a boat tour of the new breakwater and thorofare with Craig Hill of Hill’s Resort, Priest Lake residents Ken Hagman and Randy Ramey, and Mike Szybnski of Elkins Resort on Thursday afternoon, the sentiments were similar.

“In all of my years on the Water Board, this is one of the best projects that we’ve ever done,” said Roger Chase, former chairman based in Pocatello. “It’s great to see it in person.”

Extending the height of the outlet gates will give the Idaho Department of Water Resources additional flexibility in managing Priest Lake levels in dry years, IDWR hydrologist Matt Anders explained in a presentation looking at the challenge of managing lake levels when snowpack and lake inflows are below normal.

Idaho state law requires IDWR to maintain Priest Lake levels at full pool. In years with surplus snowpack and spring rain, it’s easier to maintain the full pool than it is in dry years, Anders explained. In fact, in 2021, water inflow into upper Priest Lake and main Priest Lake was one of the lowest in 70 years, he said.

Having little to no surplus water means paying very close attention to the weather, snowpack, and water inflows to keep the lake level at full pool, he said. IDWR policy calls for maintaining a minimum flow of 60 cubic feet per second in the Priest River, below the outlet dam. So there is a balancing act at play, he said.

“There’s some science here, but quite a bit of art,” Anders said, complimenting IDWR Northern Regional Manager Doug Jones for maintaining the lake at full pool in the very dry year of 2021, plus keeping the Priest River at over 100 CFS through July and August.

Looking back at the last 70 years of water records dating back to 1951, Anders showed on average how many days the lake dropped below full pool: 11 times in June; 8-10 times in July; 30 times in August.

IDWR’s plans to elevate lake levels by several inches in a dry year to provide more flexibility “is a good strategy,” he said. “When we have the ability to store up to 6 inches of surplus flow with the new outlet gates, that will give us more flexibility to ensure we can keep the lake at full pool, while also providing enough flow in the Priest River below,” he said.

Experience has shown that it’s important not to keep the lake too full or it has impacts on docks and beach levels, Anders noted. Somewhere between 3.1 to 3.5 inches seems to be the sweet spot in dry years, he said. In wet years, the target is at 3.1 inches, knowing snowpack and inflows will be higher to maintain full pool, he said.

In other action, the board:

• Heard a presentation from Chip Corsi, Northern Regional Manager of the Idaho Department of Fish and Game, about a water-siphon concept to pipe cold water from below the surface in Priest Lake and convey it to the Priest River below the outlet dam to cool off the river to benefit native cutthroat trout and bull trout. A number of Priest Lake residents came to the Water Board meeting to express their concerns about the project. IDFG will hold a virtual public meeting on Wednesday, Sept. 22, at 6 p.m. about the proposal. More information here.

• In accordance with HB 266, passed during the 2021 legislative session, the Board approved a one-year authorization of existing cloud-seeding programs operating in the state. The bill also directs the Board to evaluate whether cloud seeding to augment snowpack and water supply could be effective in other areas of the state. Currently, aircraft and/or ground-based cloudseeding infrastructure are in place to seed winter storms in the Upper Snake, Big Wood, Boise and Payette River basins. Research has shown that in general, cloud-seeding operations can increase winter snowpack by 5-15% percent, dependent upon the level of program build out and winter weather conditions.

• The board also approved a one-year pilot project for aircraft cloud-seeding in the Bear River Basin, awarding the contract to the low-bidder, North American Weather Consultants. North American currently operates a ground-based cloud seeding program in the Utah portion of the Bear River Basin, officials said. The pilot project is intended to implement airborne cloudseeding operations this winter and provide the board with information to help build out a more comprehensive program in the Bear River Basin.