With flood season in its final weeks, the Chehalis Basin Board received updates on its Erosion Management Program and Skookumchuck Dam removal study options in its regular monthly meeting last Thursday.
Preventing River Bank Erosion
Nate Kale, the aquatic species restoration plan manager for the Chehalis Basin Board, broke down the Erosion Management Program.
Kale said fighting erosion on river banks that threatens properties while preserving and benefiting aquatic species throughout the Chehalis Basin were the main goals of the program. He added that the program has currently been allotted around $850,000 by the Chehalis Basin Board.
While some pilot erosion prevention projects have already been launched, the bulk of the program’s work will be launched in the 2023-2025 biennium, Kale said.
“Our next few steps are gonna be reaching out to folks that we think will be sponsors for the projects, probably primarily conservation districts, talking to them about more support for this program and trying to get them ready for when the budget is finalized,” Kale said.
The two pilot programs have been erosion prevention steps put in place along the river banks of the Satsop and Newaukum rivers, as previously reported by The Chronicle.
The Future of the Skookumchuck Dam
Anchor QEA Senior Managing Scientist Merri Martz provided the Chehalis Basin Board with details on the progress with analyzing Skookumchuck Dam options. TransAlta still owns and operates the dam; however, the company has shut off one turbine and plans to have the dam fully shut down by 2025 as part of a longstanding agreement with the state.
A study has been researching whether the dam should be removed and how that would affect both flooding events and fish habitat.
Martz explained multiple options are being considered: maintaining the current dam’s operation, a fish passage only alternative, a flood storage only alternative, both fish passage and flood storage or removing the dam entirely.
Thorough research has already been conducted into all options focusing on both river flood levels and fish populations. In Martz’s opinion, retaining the dam and putting in a new fish sluice to improve fish passage is the best solution.
“Some of the advantages to that are you can avoid the spillway. Water spills over the spillway and fish coming through the existing fish sluice go through the spillway and come out into a filling basin, which has a lot of complex hydraulics that doesn’t make it very attractive for fish to be able to move on downstream,” Martz said.
The area’s topography also came into play when recommending this option, Martz said.
Kale added dam removal, while the most beneficial to fish, would also be the most opposed option, but not just for its effect on flooding.
“This option is strongly opposed by TransAlta, who owns the dam and operates the water right. It’s also strongly opposed by the cities of Centralia and Chehalis who are looking to that water right for their future growth,” Kale said.
According to Kale, the next step in the study is for the Chehalis Basin Board to accept public comments on the matter as they consider which option to pursue.
