The Chehalis Basin Strategy is a network of partners who are hard at work to make the Chehalis Basin a safe, healthy, and plentiful place to live—for people, fish, and wildlife.

How the Chehalis Basin Strategy Takes Action

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Helping residents and communities protect homes and businesses from flood damage

Working with landowners to slow harmful erosion and restore habitats for salmon and other aquatic life

Preparing the region for more frequent major and catastrophic flooding

What happens in the Chehalis Basin matters for all of Washington, and beyond.

The 2,700 square mile Chehalis Basin in southwest Washington reaches from the forested, rolling hills of the upper Chehalis River, to fertile farmland and valleys, and finally to the marshes and beaches of the Pacific Coast.

The Basin’s rich history and present-day reality are shaped by the ancestral heritage of numerous tribes. Today, the land continues to be stewarded by the Confederated Tribes of the Chehalis Reservation and the Quinault Indian Nation, which has treaty rights to fish, hunt, and gather in the Chehalis Basin.

The Chehalis Basin region in southwest Washington
The Chehalis Basin region in southwest Washington.

Salmon and Steelhead

The Chehalis Basin is the only major river basin in Washington with no salmon species listed as threatened or endangered.

Nature-based Economies

The region’s agricultural community alone brings in $650 million every year for the state of Washington. Forestry and fishing have also long served as economic engines within the Chehalis Basin.

U.S. Interstate 5

I-5, the West Coast’s key transportation corridor for commerce, food supplies, and public health, runs directly through the heart of the Chehalis Basin and its floodplains.

100+ Chehalis Basin Strategy projects are making a difference

Montesano Wastewater Treatment Plant: Protecting communities from sewage spills during floods

  • The Montesano Wastewater Treatment Plant was in serious danger of being breached during flooding, potentially sending millions of gallons of raw sewage all the way to Grays Harbor.
  • Natural, log-based protections were installed in the river.
  • During January 2022 floods, the protections saved the community from $40 million worth of damages.
Montesano plant
Before protections were installed, the Montesano Wastewater Treatment Plant was in jeopardy with the Wynoochee River’s bank eroding 17 feet a year.

Smart Investments That Work

The Chehalis Basin Strategy and its partners use science-based innovations to make smart investments in projects that work. We have a track record of implementing strategies that pay off—and by coordinating efforts across the Basin, we’re having an even greater impact.

Pump Station & Levee Improvements at the Chehalis-Centralia Airport

Initial investment: $1.1 million
Return on investment from protected jobs and revenue during January 2022 flooding:

Labor Income
Value Added
Business Revenues

What’s New

The latest news, announcements, and publications from the Chehalis Basin Strategy.