A planned deep drawdown of Detroit Lake in fall 2026 is drawing formal objections from the City of Salem and Marion County, which argue the U.S. Army Corps of Engineers has not adequately addressed risks to downstream drinking water treatment, turbidity and fish mortality. The dispute centers on a federal effort to improve fish passage at Detroit Dam while limiting harm to communities that depend on the North Santiam River.
The Corps is studying the deeper drawdown as part of a Supplemental Environmental Impact Statement tied to a 2024 Biological Opinion from NOAA Fisheries. According to the Corps, that opinion requires a deeper fall drawdown at Detroit Reservoir to support endangered fish moving through the dam. The drawdown is not expected until fall 2026, and the agency has said the environmental review is intended to evaluate effects on water quality, local communities and dam operations.
Salem’s concern is not that taps would automatically run dry. The city’s position is narrower and more credible than that: officials say high turbidity from suspended sediment could make river water too difficult to treat at the Geren Island plant for a period of time, forcing Salem to rely on backup sources instead. In a Jan. 13 statement, the city said the Corps’ updated approach addressed some earlier concerns by moving the drawdown later in the year, limiting the lowest drawdown period to two weeks and taking the operation in deeper steps over several years. But Salem said the plan still lacks clear turbidity triggers and required corrective actions if conditions become too severe for safe treatment operations…