Thurston County supports Chehalis Basin efforts minus dam endorsement 

Thurston County joined 12 jurisdictions backing Chehalis Basin flood management efforts after revising a resolution to align with its position on dam infrastructure decisions. 

The Thurston County Board of County Commissioners passed the resolution supporting continued state funding for flood mitigation and aquatic species restoration efforts during its work session on Wednesday, Dec. 3. The resolution is subject to legal review. 

Board Chair Tye Menser modified the original text to reflect the county's stance of engaging in the process without committing to projects until all alternatives and tribal input are reviewed. 

The original resolution called for the county to "express continued support for the proposed flow through dam for flood control and the hope it offers families and communities across the Basin for reducing the peaks of future catastrophic flooding." 

Instead, Menser replaced that language to back "a Chehalis Basin-wide solution that provides flood safety, protects fish, and is supported by all Basin partners, including Tribes, with the hope such a solution offers to families and communities across the Basin." 

Basin partners want to demonstrate unified backing when seeking legislative funding, Menser explained. He then removed language that conflicted with Thurston County's position. 

The county has never taken a position on whether to support any dam structure in the basin, Menser said. 

"We have taken the position in the past that we want to see what the total analysis of the land alternatives are, and see what the tribal input is," Menser said. "The jury's still out from Thurston County's perspective on whether we would support a flood retention facility like (what) has been proposed." 

Vice Chair Wayne Fournier, who brought the resolution request to the board, agreed with the approach. 

"This was a lot of different things that their work encompasses," Fournier said. "So it's more of a strategy, more than specifically naming projects that we support." 

Scott Boettcher, a private consultant under contract to Lewis County, attended the work session to answer questions about the resolution and flood strategy. He has served as staff to the Chehalis River Basin Flood Authority since 2011. 

He recounted the collaborative approach that has secured legislative funding. 

"We are collectively in a process called the ‘Chehalis flood strategy processm,'" Boettcher said. "We are doing projects on the ground, pumps, treatment plant protection, flood warning system, habitat. Those things are all happening." 

The Washington Legislature has funded the effort for six consecutive budget cycles, Boettcher said. 

"Because we are all banded together and working so well, the Legislature has funded biennium after biennium, six biennium strong, healthy sums of money that allow us to tackle problems on the basis of information," Boettcher said. "Your participation of support helps ensure that we get another healthy round of analysis." 

Menser then explained the county's past hesitation on similar resolutions. 

"When this came up a few years ago, we decided not to do it," Menser said. "So, Thurston County actually didn't sign the resolution." 

Resolution provisions 

The original resolution laid out the flood authority's position through multiple "whereas clauses." Climate change will bring larger and more frequent catastrophic flooding, the resolution stated. 

The Chehalis Basin strategy encompasses the Aberdeen-Hoquiam North Shore levee, local flood and fish projects, an aquatic species restoration plan and a proposed flow-through dam designed to retain 62,000 acre feet of floodwater during catastrophic storms. 

The flood authority backed the flood control district's proposed project in April 21, 2020, and Nov. 13, 2020, letters submitted through state and federal environmental review processes. 

The U.S. Army Corps of Engineers examined 61 alternatives for reducing catastrophic flood damage. Only alternatives featuring a water retention facility met flood damage reduction objectives sufficient for full analysis, the corps determined. 

The flood authority includes Thurston County, Lewis County, Grays Harbor County, Hoquiam, Aberdeen, Cosmopolis, Montesano, Oakville, Bucoda, Centralia, Chehalis, Napavine and Pe Ell. All members are regularly and negatively impacted by Chehalis River Basin flooding, with the largest source originating from the mainstem Chehalis River above Pe Ell. 

Since its establishment, the authority has approved more than 140 projects that protect nearly 300 acres of new habitat for salmon and other species, and safeguard more than 200 homes and businesses from flooding. 

Thurston County once held a seat on basin work groups but no longer has representation on the basin board, Menser noted, as reported by The JOLT News in October. 

Environmental review

The Washington State Department of Ecology released a revised draft environmental impact statement on Nov. 20, which analyzed a proposed flood retention facility and airport levee improvements. The department opened a 75-day public comment period, which runs until Feb. 4, 2026. 

The flood control district is seeking to build the facility. It would allow the river to flow unimpeded most of the time, but would close gates during major floods to create a temporary reservoir storing up to 62,000 acre feet of water. 

The project would prevent inundation of 3,514 acres during a major flood and 3,795 acres during a catastrophic flood. Major floods exceed 38,800 cubic feet per second at the U.S. Geological Survey Grand Mound gauge. That threshold has been reached three times in the past 20 years. 

The Chehalis Basin Board plans to decide which projects to recommend in early 2026. Members represent the flood authority, Quinault Indian Nation, Confederated Tribes of the Chehalis Reservation, and agricultural, environmental and economic interests. 

The Washington Legislature launched the Chehalis Basin Strategy in 2016 after five of the largest floods on record occurred within 30 years. It has provided $70 million, then $75 million, and another $75 million in 2025-27, according to Office of Chehalis Basin Director Jeff Zenk.