Fish and flooding: Tabletop exercise considers Chehalis Basin Strategy, which might be finalized by late 2026


What could a long-term strategy for the Chehalis River Basin’s communities and ecosystems look like? 

Though a plan will not be finalized for roughly three years, that was the focus of discussion during two days of Chehalis Basin Board meetings last week. Board members were asked to come up with a list of different packages of scenarios for flood control, mitigation and aquatic species protection in the basin.

Following the exercise, Ken Ghalambor, a senior associate at Ross Strategic, said there was a need for “additional data collection and analysis over the next year or so.”

“So that we can have more precise definitions and detail about the different components within each of the packages,” Ghalambor said. “So, they’ll essentially need to do this whole exercise again when they have more detailed information. And this is helping inform us on what type of information they need moving forward.”

Ross Strategic, a Seattle-based environmental consulting firm, is tasked with coordinating technical analysis for the Chehalis Basin Board.

Thursday’s tabletop exercise served as a brainstorming session, of sorts. Board members weren’t asked to craft plans they preferred or necessarily thought would be implemented.

Instead, the different scenarios were a “range of packages for consideration that may or may not align with what the board ultimately considers to be a viable package for a long-term strategy,” according to Ghalambor.

Price and feasibility did not factor into the discussion, which instead centered on broader impacts of climate change and opportunities to restore the salmon populations. Board members were divided into two subgroups tasked with independently designing their flood reduction strategy.

“I think being able to protect homes, families, businesses, infrastructure from significant flooding and maintaining a vital, abundant, aquatic species population for the basin are probably the two overarching things,” Ghalambor said. “But then there’s a lot of, sort of, social, political, economic, considerations that they’re taking into account.”

Groups had an array of possible scenarios when dealing with the different options. For the Skookumchuck Dam, should the strategy include the dam’s removal with an off-channel strategy or dam removal only? Should fish passage or flood reduction be prioritized? Should a combination of a fish and flood move forward? Or should the board leave the dam as is, with no significant action taken?

The board members also considered how the different elements interacted with each other.

Following the session, Ghalambor said some of the packages may be further evaluated while the board continues to develop a comprehensive strategy.

According to a timeline presented during the meeting, the board will continue developing preliminary packages through the first quarter of 2024. From there, members will finalize and evaluate the packages through the first quarter of 2025 before calculating the results of a package in the first quarter of 2026.

A long-term strategy that implements flood risk reduction, aquatic species restoration and other values should be finalized in the latter part of 2026.

“We’re taking it step by step, so it will be dependent on how the process goes along and what the board wants to see, and how fast they’re able to move through their process,” Ghalambor said.