Chehalis Basin Board delivers projects while planning for future

As the independent Chehalis Basin Board marks a milestone of having 241 local flood reduction and habitat restoration projects constructed or in progress, the Board continues to evaluate three large-scale infrastructure proposals aimed at controlling flooding in the Chehalis River Basin in southwest Washington.

The Board remains on task to recommend a flood protection and habitat restoration strategy for salmon and other aquatic life in Washington's second largest watershed to the Washington Legislature later this year. The Board and Ecology's Office of Chehalis Basin (OCB) are weighing whether the long-term Chehalis Basin Strategy should include:

• A unique flow-through flood-control dam on the Chehalis River near the town of Pe Ell
• A new system of levees built in and around the cities of Centralia and Chehalis
• Changes to the Skookumchuck River dam in Thurston County to improve fish passage and flood control

The proposed Chehalis River dam is currently under state and federal environmental review by Ecology and U.S. Army Corps of Engineers. The other two infrastructure projects are still conceptual.

Interim Board Chair Scott Brummer said the last six months of studies about the proposed infrastructure projects have revealed important questions still remain.

"These proposals will shape the future of Chehalis Basin communities for generations to come. It is vital that we carefully evaluate the potential cultural, economic and environmental impacts," Brummer said. "We are working hand in hand with OCB to get the best possible information to assess the costs, feasibility and trade-offs associated with the projects."

He said the long-term strategy will include a plan outlining how the Board will address its remaining questions about the projects.

This summer, representatives from the Board and OCB will be at community fairs and festivals across the Basin to share information about the strategy, including 241 flood control and habitat restoration projects that are already in place or under construction in the Basin, as well as the three infrastructure projects currently under consideration.

Managing water in the Chehalis River Basin

While the Board and OCB assess the proposed infrastructure projects, they continue to identify and fund other projects with the potential to protect flood-prone areas and restore aquatic habitat for salmon, steelhead and other aquatic life in the Chehalis Basin.

Since July 2017, the Board and OCB have invested $260 million to fund 241 projects that are helping the Basin undergo a positive transformation. Projects include building new municipal pump stations, elevating at-risk homes, removing barriers to ease salmon migration and forming new breeding pools for endangered Oregon spotted frogs.

"With direction from the Board and hard work by our OCB staff, we've been able to deliver more than 200 flood-damage reduction and habitat restoration projects that are helping boost local economies and improving the quality of life for basin's 191,000 residents," said Ecology Director Casey Sixkiller. "This work is critical because what happens in the Chehalis River Basin matters to everyone in Washington."

Sixkiller said the 154 habitat restoration projects, 64 flood control projects and 23 projects that provide flood relief and habitat restoration were all done on time and on budget, with various local, Tribal and state partners taking lead roles planning and completing the projects.

Recovering and enhancing aquatic habitat in the Chehalis Basin is critical to Washington's broader salmon recovery efforts.

Sixkiller noted while salmon runs in the Chehalis Basin have declined dramatically in the last 100 years, it is still the only major river system in Washington where no salmon species has been federally listed as threatened or endangered.

"By working together, we can help rebuild the abundant runs of salmon and steelhead that once thrived in the Basin," he said.

Safer communities, stronger ecosystems

The Chehalis Basin faces an array of flood- and habitat-related challenges. A century of intensive land use significantly altered its waterways and landscapes. Salmon runs have declined dramatically due to habitat degradation or loss.

While flooding has always been common in the Basin, climate change is resulting in stronger, more frequent storms, with six of the largest recorded floods occurring in the last 30 years alone. Scientists warn that these trends will get worse as weather patterns become more unpredictable.

OCB Director Nat Kale said the historic floods that ravaged other Washington river basins in December 2025 highlight the importance of having these flood reduction and aquatic habitat restoration projects in place in the Chehalis.

"This portfolio of smart investments, robust participation by willing landowners and skilled leadership by our local, Tribal, state and nonprofit partners are helping us to build a safer, more resilient Chehalis Basin for everyone," Kale said.

Tackling flood challenges, improving 'bounce back' ability

To protect Basin residents, communities and ecosystems, the Board and OCB have invested about $130 million for 64 projects that lower flood-related damage and improve the ability of residents, businesses and communities to prepare for and bounce back when high water events occur.

According to the National Institute of Building Sciences, for every $1 spent on flood resilience, communities save $6 in future disaster response and recovery costs. Basin flood control projects often involve heavy construction and complex land acquisitions and permitting so they generally cost more and take longer to complete than habitat restoration projects.

Most flood projects are managed through the Chehalis River Basin Flood Authority which is made up of representatives from three counties and 10 towns and cities within the Basin. Established in 2008, the Flood Authority administers local flood projects and operates the cutting-edge Chehalis River basin flood warning system.

Significant flood reduction projects include:

• Constructing five new municipal pump stations to keep the Chehalis-Centralia Airport dry during storms and protect 1,200 more residents and businesses in Aberdeen and Hoquiam from flooding and storm surges. Three more pump stations to protect another 5,000 properties are being planned.
• Keeping the Montesano Wastewater Treatment Plant from being breached by the Wynoochee River using a network of strategically placed log structures.
• Elevating eight family homes in the Basin, from Aberdeen to Bucoda, at risk of flood impacts. Another 10-12 home elevation projects are planned.
• Installing flood alert gauges at seven new locations throughout the Basin. When flood conditions occur, the Flood Authority uses gauge data to send out more than 5,400 early warnings to Basin residents.
• Constructing 23 raised farm pads in Grays Harbor and Lewis counties safeguarding Basin farms, livestock and equipment during floods.
• Awarding $5.2 million to the city of Centralia to reduce flood impacts from China Creek during storm events.
• Contributing $71,600 to help the Northwest Agriculture Business Center, a consortium of local grain farmers, build a new storage facility and food hub at the Port of Chehalis.
• Providing $781,000 to the city of Chehalis and Port of Chehalis to help them develop a joint plan to identify and manage shared flood risks.
• Supporting the Coal Creek project in Centralia to improve local wetlands and create stormwater storage near the Southwest Washington Fairgrounds.

Returning natural processes helping boost aquatic habitat

To support healthy, harvestable salmon and steelhead populations, OCB and the Board have invested $118 million for 154 projects restoring aquatic habitat. Besides fish, these projects are helping other water-dependent species including the endangered Oregon spotted frog.

All of the projects support the science-based aquatic species restoration program, an integral part of the strategy guided by the Confederated Tribes of the Chehalis Reservation, Quinault Indian Nation and Washington Department of Fish and Wildlife.

Tribal and state experts work with willing landowners, conservation districts in Grays Harbor, Lewis, Mason and Thurston counties, land trusts, conservation entities and other partners to restore the natural processes that shape aquatic habitats and make Basin waterways more resilient to drier summers, higher water temperatures, more frequent intense storms and other climate-driven challenges.

Most projects involve planting native trees and shrubs in and along stream and riverbanks, removing invasive plant species such as knotweed and Himalayan blackberries, constructing and installing engineered log jams and reconnecting floodplain and off-channel habitats.

In less than a decade, these projects have:

• Restored and protected nearly 600 acres of new aquatic habitat
• Opened up 20 new river miles for salmon, steelhead and other aquatic species
• Removed or corrected 40 barriers, making 117 more stream and river miles passable for migrating fish

Some significant restoration projects include:

• Using innovative restoration techniques to transform a simple stream channel in Schafer Creek near the city of Montesano into a complex mosaic of habitats for salmon, trout and other species
• Overseeing significant restoration projects on the Satsop, Skookumchuck and Wynoochee rivers and in Stillman Creek that have restored about 13 miles of important aquatic and streamside habitat
• Installing ponds and managing wetland vegetation to support breeding and overwintering habitat for threatened Oregon spotted frogs in Thurston County

Integrated investments

In the past nine years, the Board and OCB also have invested $12 million to fund 23 projects providing both flood relief and habitat restoration. Many of these measures slow stream and riverbank erosion using natural materials which also create and protect aquatic habitat.

The Board and OCB, for example, worked closely to invest $1.4 million for the Haul Road project that also involved the Flood Authority, Port of Grays Habor, Lewis County and the cities of Centralia and Montesano.

For years, erosion along the Chehalis River threatened Haul Road which contains critical water infrastructure and supports Grays Harbor Energy's power plant at Satsop Business Park. In 2022, near-record flooding almost washed away the buffer between Haul Road and the river. In response, the Port of Grays Harbor and its partners placed engineered log jacks along 500 feet of the riverbank to slow river flow, capture woody debris and create new aquatic habitat.

About the Board and OCB

The Washington Legislature created the Board and OCB within Ecology in 2016 after historic, record-setting floods struck the Basin in 2007 and 2009, causing more than $1 billion in damage. Floodwaters submerged homes, businesses, farms and infrastructure and topped U.S. Interstate 5, closing the West Coast's primary north-south arterial for several days.

The seven-member Board leads and shapes the Chehalis Basin Strategy, including selecting projects to fund. It is made up of community leaders who bring diverse interests and perspectives to the table. Members represent the Flood Authority, Confederated Tribes of the Chehalis Reservation, Quinault Indian Nation and agricultural, economic and environmental interests.

OCB works in partnership with the Board to administer state funding and leads a coalition of local, Tribal and state partners to protect and preserve the Basin for people, fish and communities for coming generations.