Department of Ecology News Release - May 13, 2021

Ecology adopts new watershed plan for Duwamish-Green river basin

Flowing Green River. Photo courtesy Greg Volkhardt.


A new watershed plan for the Duwamish-Green river basin lays out projects and actions to protect and improve fish habitat, while also ensuring sufficient water is available for rural residents. The Washington Department of Ecology adopted the plan for the Duwamish-Green watershed, also known as Water Resource Inventory Area (WRIA) 9 on May 11.

The WRIA 9 watershed plan, which covers portions of King County, is part of a statewide undertaking to improve rivers and streams.

“I applaud the Duwamish-Green planning group’s dedication and collaboration to develop a new watershed plan, especially amidst the challenging times of a global pandemic,” said Ecology Director Laura Watson. “The group delivered solutions that ensure water for both communities and fish.”

The Duwamish-Green Watershed Restoration and Enhancement (WRE) Committee, consisting of representatives from tribal and local governments, state agencies and local interest groups, began planning in late 2018. On Feb. 24, the committee submitted a locally-approved plan for Ecology’s review. The department is adopting the plan ahead of a June 30 statutory deadline.

WRIA 9 is among 15 watersheds identified in a streamflow restoration law that requires a watershed plan or plan update. The planning law helps improve streamflows to levels necessary to support healthy and sustainable native fish populations while also providing water for homes in rural communities.

“Ecology’s staff provided the diligence, structure, and focus that was needed for the committee’s various jurisdictions to develop a WRE Plan for the entire Green-Duwamish watershed,” said Joe Hovenkotter, King County Government Relations Officer. “The plan will be a valuable reference for assessing future water supply and a tool for restoring streamflows.”

The WRIA 9 watershed plan forecasts the number of new domestic permit-exempt wells between years 2018 and 2038, and their potential impacts on streamflows. The plan recommends 16 projects and actions such as buying water rights, recharging aquifers and improving aquatic habitat that, if completed, will offset the impacts of additional domestic wells and provide a net ecological benefit to the watershed.

Contact information

Curt Hart
Communications manager
Twitter: ecologywa
Mugdha Flores
Communications specialist