Cities Join Marion County in Calling on U.S. Army Corps to Halt Draining Detroit Lake
SALEM, OR — On June 22, 2026, Marion County submitted a formal letter on behalf of a community coalition to U.S. Army Corps of Engineers urging them to cancel any deep drawdown of Detroit Reservoir in 2026 and reevaluate future draining plans. The community coalition included 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.
The letter cites serious risks to downstream drinking water systems, local recreation, and local fish populations.
"The Army Corps' own analysis acknowledges that this operation would adversely affect drinking water, water supply reliability, and recreation,” said Commissioner Colm Willis, Chair. “The risks to our communities strongly outweigh any perceived, hypothetical benefits from this drawdown."
The letter comes after Marion County filed a lawsuit in May against the Army Corps. The lawsuit asks a federal court to pause efforts to drain the lake until the Army Corps completes a federally required turbidity that is more than four months overdue.
Marion County also sent letters in December 2025 and in January 2026 asking for a halt to the drawdown and perform a more formal review, pointing to the 2023 Green Peter Reservoir drawdown, which caused significant damage to downstream water filtration systems and killed hundreds of thousands of kokanee salmon. Despite those warnings, the Army Corps published its Final Supplemental Environmental Impact Statement in May without completing the required turbidity study and without establishing enforceable operational thresholds or clearly defined mitigation commitments.
The joint letter asks the Corps to refrain from authorizing any deep drawdown in 2026 and to satisfy five conditions before revisiting any future draining plan:
Complete the federally required turbidity report and conduct additional quantitative analysis of sediment transport, drinking water treatment impacts, and effects on kokanee and resident fisheries;
Establish enforceable adaptive management triggers that require modification, suspension, or termination of drawdown operations if water quality, recreation, or fishery impacts exceed defined thresholds;
Demonstrate through data that prior Willamette Basin drawdowns have produced measurable improvements in fish passage sufficient to justify the documented risks;
Consult directly with downstream water providers, local governments, and emergency managers to establish operational coordination and emergency response protocols before any action; and
Identify and commit mitigation funding in advance for impacts to drinking water systems, local businesses, and resident fisheries.
The letter also highlights current drought conditions and below-average snowpack across Oregon as additional reasons for caution. The Corps' own SEIS acknowledges that in dry winters, it may be unable to refill Detroit Reservoir to minimum conservation pool by February, which could compound harm to downstream water supplies.
"Any changes to Detroit Lake's water level must be grounded in data-backed science with meaningful protections in place for our downstream communities," said Commissioner Danielle Bethell. "We will continue working to ensure that decisions made at the federal level align with the needs of local communities."
"Our residents depend on clean, reliable drinking water," said Commissioner Kevin Cameron. "The Army Corps should complete the analysis required by law before taking on any risks that could harm that supply."