Cougar Dam & Reservoir Downstream Fish Passage Project

The U.S. Army Corps of Engineers is conducting an environmental review to aid in developing a project to provide downstream fish passage for Upper Willamette River Chinook at Cougar Dam. Cougar Dam and Reservoir is in Lane County on the McKenzie River about 40 miles east of Eugene. Learn more by about the project here: Cougar Downstream Passage fact sheet.


Cougar Dam, east of Eugene, Ore. on the McKenzie River, provides a variety of functions including flood risk management and power production. However, it also blocks fish passage and the U.S. Army Corps of Engineers is in the process of implementing fish passage at this site.

The Corps operates and maintains 13 multipurpose dams and reservoirs (including Cougar Dam and reservoir) in the Willamette River Basin in Oregon, collectively referred to as the Willamette Project

The listing of several species under the Endangered Species Act (ESA) requires the Corps to perform an assessment of the Willamette Project and its operations’ impact on listed species. Based on this assessment, the National Marine Fisheries Service (NOAA Fisheries) released a Biological Opinion (BiOp) in 2008 which identified the required actions to avoid jeopardizing the existence of ESA listed fish in the Willamette basin. These include downstream fish passage at Cougar Dam by making structure modifications or major operational changes.

Upcoming Public Meetings

There are no scheduled upcoming public meetings at this time. Check back for future meeting dates. 

NEPA - The Environmental Policy Act Process, Scoping Phase and Your Role

The National Environmental Policy Act of 1969 (NEPA) is one of the nation’s oldest environmental laws that encourages federal agencies to make environmentally responsible decisions. NEPA requires all federal agencies to consider and disclose the environmental effects of their proposed actions in an Environmental Impact Statement (EIS) or Environmental Assessment (EA). The Citizen's Guide to NEPA explains this law and how to effectively submit your input.

Per NEPA, an EA assessing impacts of the proposed project on the human environment will be provided to the public for review and comment. The public will be notified when opportunities for comment arise. Collecting the right level of information at the right time is important to developing a project plan, requiring early and frequent engagement of all affected federal, state and local agencies, Native American Tribes, and interested groups and individuals. 

Examples of areas for evaluation in the EIS include:

Air Quality
Cultural Resources
Floodplain Management
Economic Impacts
Environmental Justice
Land Use
Migratory Birds
Sediment Transport, Deposition, Composition
Social Considerations
Endangered Species Act
Tribal Interests
Water Quality
To provide opportunities for the public to learn about the project, the Corps will continue to provide project updates on the project website. If you would like to be included in the project distribution list to receive updates on the project via email, please send an email with the subject line “Cougar Downstream Passage Distribution List” to the project email: Interested parties can also send questions to the project team via the project email or by calling the Corps’ Public Affairs Office at 503-808-4510. Once we have a draft EA, the public will be provided an opportunity to review and provide comments. Public meetings will be held to present the preferred alternative, answer questions, and provide an opportunity for members of the public to submit written comments. The Corps will consider these comments when finalizing the EA. The public will then be provided an opportunity to review the final EA.

We want your input!

We understand the importance of Cougar Dam and Reservoir to the communities of the McKenzie River Basin and will work with you to identify and minimize the impacts associated with building and operating a downstream fish passage solution. We will use the information you provide about the potential effects of the preferred and other alternatives to inform the design, construction, and operation of a downstream fish passage solution.