A public comment period for ending hydropower production at federal dams in the Willamette River basin, and thoughts on deep drawdowns at Detroit Reservoir on the North Fork Santiam River, has been extended from June 6 to June 21.
Comments on the two subjects will help the U.S. Army Corps of Engineers complete its Supplemental Environmental Impact Statement focused on two new requirements related to the operations and maintenance of the Willamette Valley System of dams and reservoirs, a Corps news release says.
“As part of the National Environmental Policy Act (NEPA) process, we collect public comments to help us shape what we study in the SEIS – we call this process public scoping,” said Liz Oliver, the Portland District project manager leading the SEIS process. “Because these proposed changes are important, we want to make sure everyone has enough time to share their thoughts. Extending the deadline gives more people a chance to participate and helps us make better, more informed decisions.”
In April 2025, Portland District completed a six-year study on the operations and maintenance of the Willamette Valley System of dams and reservoirs and published an Environmental Impact Statement. The EIS helps the Corps understand how its operations effect the environment, people, and ecosystems—and examines “alternatives,” or different ways the Corps could adjust operations. Shortly before the EIS was finalized, two new federal requirements were introduced. These additions prompted the need for a SEIS, which is now open for public scoping.
The Corps’ SEIS will evaluate:
- Implementing a deeper fall drawdown at Detroit Reservoir: To support endangered fish, as required by the National Marine Fisheries Service. The drawdown is not expected to occur until fall 2026, and the Corps will evaluate its effects—such as potential impacts to water quality and local communities—in the SEIS.
- Studying a permanent end to hydropower production at Willamette Valley dams: As directed by Congress in the Water Resources Development Act of 2024. This step is necessary to complete federal consultations and environmental compliance under NEPA.
For more detail, see: CBB, May 23, 2025, CORPS SEEKS PUBLIC COMMENTS ON SUPPLEMENTAL EIS FOR WILLAMETTE RIVER BASIN DAMS, WANTS VIEWS ON ENDING HYDROPOWER, HTTPS://COLUMBIABASINBULLETIN.ORG/CORPS-SEEKS-PUBLIC-COMMENTS-ON-SUPPLEMENTAL-EIS-FOR-WILLAMETTE-RIVER-BASIN-DAMS-WANTS-VIEWS-ON-ENDING-HYDROPOWER/
The Corps will accept comments via email or mail through June 21.
Email: [email protected]
Mail: U.S. Army Corps of Engineers
Attn: CENWP-PME-E / Willamette EIS
P.O. Box 2946 Portland,
OR 97208-2946
More information, including a video of a previous public scoping comment sessions, is available at https://www.nwp.usace.army.mil/WVS-EIS/