Army Corps looks at possible environmental impacts of Willamette Valley dams project

Adam Duvernay, Register-Guard
·2 min read
The Cougar Dam Powerhouse in the Cascades east of Springfield.
The Cougar Dam Powerhouse in the Cascades east of Springfield.

The U.S. Army Corps of Engineers Portland District will host an informational session next week on changes to its system of dams to better preserve endangered species while maintaining the dams' operational missions.

Engineers are considering major changes that may impact operations and maintenance of the Willamette Valley System, a series of flood control dams and reservoirs regulating local river systems. The changes would correct some of the issues caused by the dams, such as blocking the spawning grounds of Chinook salmon and other fish.

The Corps is developing an environmental impact statement, a document outlining the impacts of a proposed project. The Corps is inviting the public to a listening session on its progress ahead of a public input period when the draft document is ready in the fall.

Related: At Cougar Dam, saving endangered fish means changing typical fall operations, power production

The Corps is required by court order to adjust operations at its dams on Willamette River tributaries in order to better facilitate fish passage up- and downriver. In 2020, a judge ruled the Corps' dam and reservoir operations violated the Endangered Species Act.

A ruling in September required the Corps to take immediate action at Cougar and Foster dams, including a deeper-than-normal winter drawdown of Cougar Reservoir. The ruling also required the Corps to study and take further steps to alleviate fish migration issues.

More on that ruling: Judge orders immediate actions at Willamette Basin dams to help salmon, steelhead

Chinook salmon swim in a holding pond at the Leaburg Fish Hatchery on the McKenzie River.
Chinook salmon swim in a holding pond at the Leaburg Fish Hatchery on the McKenzie River.

Corps Portland District spokesman Tom Conning said developing an environmental impact statement is a process separate from court injunctions but tackles related issues.

The Corps is looking into alternatives for its regular operations that may include:

  • High-value structural options

  • Floating fish facilities

  • Temperature control towers

  • Operations that may impact some authorized purposes

  • Water release through diversion tunnel, regulating outlets, delayed refills or spillways, which could affect recreation, water supply and water temperature

  • A combination of the structures and operations

Before the informational session on Wednesday, Jan. 19, people can view online videos, digital boards, slides and maps to aid understanding of the environmental impact statement.

That virtual information can be seen at https://gather.cdmsmith.com/v/NkjxE7ErqlQ.

How to attend

When: Noon to 1:30 p.m. Wednesday, Jan. 19

Web link: https://bit.ly/3K2kEdY

Join by phone: 1-844-800-2712

Access Code: 2760 992 4137 #

Password: cxC49jdpJ7?

Contact reporter Adam Duvernay at aduvernay@registerguard.com. Follow on Twitter @DuvernayOR.

This article originally appeared on Register-Guard: Army Corps to host session on planning changes at Willamette Valley dams