A group of agencies and local governments is urging the U.S. Army Corps of Engineers to halt plans to draw down the Detroit Reservoir on the North Santiam River later this winter.

In a formal letter, Marion County officials joined several other agencies demanding the Army Corps not only cancel its deep drawdown of the reservoir, but also reevaluate any future draining plans.

The federal agency is looking to draw down the reservoir in an effort to improve habitat for endangered Chinook salmon and steelhead fish. The agency is hoping this will help the fish move more easily along the Santiam River.

But officials in the area say this could cause more damage than good. In the letter, which was submitted on June 22, officials raise several concerns associated with the drawdown, including harmful effects to the region’s drinking water.

Officials point to this year’s drought conditions and the below-average snowpack across Oregon as more reasons the drawdown should be halted.

“The Army Corps’ own analysis acknowledges that this operation would adversely affect drinking water, water supply reliability, and recreation,” said Marion County Commissioner Colm Willis. “The risks to our communities strongly outweigh any perceived, hypothetical benefits from this drawdown.”

In the letter, the group also raises concerns surrounding local fish populations and recreation. They ask the Army Corps to consider a handful of conditions before revisiting future draining plans, including showing data that prior Willamette Basin drawdowns have produced measurable improvements to fish passages.

This week’s letter follows two lawsuits filed in May against the federal agency highlighting their concerns with drinking water, wildfire readiness and harmful impacts to their area’s agriculture and tourism industries. Marion County officials previously called for the project to be paused multiple times, again mainly raising concerns around the region’s drinking water supply.

The latest letter was submitted on behalf of the cities of Stayton, Sublimity, Mill City, and Idanha as well as the Detroit Lake Foundation, Detroit Lake Marina, Woodburn Area Chamber of Commerce and North Marion Tourism Collaborative.

In an email to OPB, the Army Corps said it could not respond to the letter due to its pending litigation with Marion County.

The agency did point to comments it provided in its press release Tuesday finalizing its drawdown plans and other dam operations.

“We know how much these communities rely on clean drinking water, and how we approach a drawdown at Detroit Reservoir matters,” said USACE Portland District Commander Col. Dale Caswell. “The drawdown at Detroit has been shaped to reflect the lessons learned and to reduce impacts on downstream communities.”

News Source : https://www.opb.org/article/2026/06/24/oregon-officials-urge-cancellation-detroit-lake-drawdown/