Marion County To Immediately Appeal Ruling Allowing Army Corps To Drain Detroit Lake - 11/04/26

SALEM, OR — Marion County will immediately appeal to the U.S. Court of Appeals for the Ninth Circuit after U.S. District Judge Mustafa T. Kasubhai denied the County’s motion today for a preliminary injunction to stop the U.S. Army Corps of Engineers from draining Detroit Lake this fall.

“We are extremely disappointed in today’s decision, but this fight is far from over,” said Commissioner Colm Willis, Chair. “The Army Corps is endangering our drinking water, our farmers, our fish, and our canyon communities. We are immediately appealing to the Ninth Circuit and asking for an emergency injunction during the appeal.”

Today’s ruling did not resolve the merits of the case but would allow the Army Corps to move forward with the first year of its new policy of annual deep drawdowns, which would drain the lake to its lowest historic level, even though the Army Corps has not completed the turbidity report required by law, and despite the documented damage caused by a similar drawdown at nearby Green Peter Lake.

The underlying lawsuit continues in District Court as Marion County also seeks to stop the even deeper drawdown that the Army Corps plans to do in fall 2027, threatening the clean water supply for over 220,000 people, hospitals, schools, businesses, firefighters, farmers, recreation, fish, and the environment.

Background

Marion County filed a lawsuit on May 13, 2026, asking the United States District Court to order the U.S. Army Corps of Engineers to pause efforts to drain Detroit Lake until the Army Corps completes the turbidity report required by federal law and allows informed public comments. Congress required the Army Corps to evaluate lessons learned from turbidity problems caused by a similar draining of nearby Green Peter Lake, but the Army Corps was over four months past the legal deadline.

On August 11, 2026, Marion County filed a motion outlining the many ways federal defendants violated the law in adopting their new policy of annual deep drawdowns of Detroit Lake. This new policy will devastate canyon communities, endanger drinking water for over 230,000 people living downstream, and even jeopardize the very fish it claims to be trying to save.

Catastrophic Damage from Similar Drawdown at Green Peter Lake

In 2023, a court order forced similar deep drawdowns at nearby Green Peter Lake due to a lawsuit from an environmental group. This killed thousands of salmon and caused massive increases in turbidity that harmed downstream water systems.

Photo Credit: Brian Stone Photography LLC; explanatory text added by public commenter who submitted it during SEIS process.

The new policy of annual deep drawdowns would drain the lake below its minimum conservation pool—to its lowest historic level in the first year and to even deeper untested low levels each fall in following years. Dropping water levels in this manner disturbs fine sediment on the lake bottom and causes turbidity (dirty water), which harms all fish and municipal water systems downstream. There would also be water shortages if there is low rain that prevents refill, hurting cities and agriculture. The damage that was caused by the deep drawdown of Green Peter shows a deep drawdown of Detroit could also kill much of a lake’s fish population. All this would harm the tourism-based economy of the local community.

The Army Corps’ own analysis found that the level of low rain that causes water shortages when combined with a deep drawdown occurs one out of every four years. This year will almost certainly be one of those years. The National Oceanic and Atmospheric Administration (NOAA) predicted “a very strong El Niño during October-December of 2026 that would rank among the largest El Niño events in the historical record going back to 1950” and that El Niño conditions “will persist through early spring 2027.”