The U.S. District Court for the District of Oregon on February 25 issued a preliminary injunction order in long running litigation over Columbia River System operations.
The court granted motions for preliminary injunctive relief filed by conservation plaintiffs and the State of Oregon, finding that interim operational changes at multiple dams are warranted. The injunction takes effect beginning in spring 2026.
The order governs spill, fish passage, and reservoir operations at the four lower Snake River dams (Ice Harbor, Lower Monumental, Little Goose, and Lower Granite) and four dams along the Columbia River (McNary, John Day, The Dalles, and Bonneville), which are operated by the Army Corps of Engineers (Corps), with implications for Bonneville Power Administration (BPA) system operations.
The court orders specific “spill” regimes at each dam (in which water “spills” over the top of the dam rather than through hydropower turbines), summarized in a table on page 3 of the attachment. Core elements include:
• 125 percent total dissolved gas (“gas cap”) spill as the baseline standard at most projects during spring;
• 24 hour per day spill at multiple dams during spring and summer fish passage seasons;
• Continued use of surface passage routes (spillway weirs, top spill weirs, ice and trash sluiceways, and collectors) to favor non turbine fish passage;
• Project specific spill volumes or percentages for summer and fall/winter seasons; and
• A defined seasonal shutdown window (Nov. 16–Feb. 28/29) for freezing and maintenance, with limited exceptions.
At certain Snake River projects, notably Little Goose, the order incorporates adult passage criteria that trigger performance standard spill blocks during peak migration hours. These provisions are intended to reduce adult delay while maintaining juvenile benefits.
Beginning in 2026, the Corps must operate reservoirs within the existing 2025 operating ranges. This includes Lower Snake River pools that are generally constrained to narrow operating bands during fish passage season, and annual reporting to regional fish managers that explains any deviations or raised pool limits, particularly at the Bonneville, The Dalles, and McNary dams. This is intended to limit the agencies’ ability to draft reservoirs below biologically protective levels without transparency.
In the order, the court explicitly preserves technical management team emergency protocols, which allow temporary deviations for generation, transmission, fish facility failures, or safety emergencies. It also preserves pre coordinated operations and variances already embedded in the Corps’ 2025 Fish Operations Plan.
Adjustments necessary for energy emergencies, human safety, or infrastructure integrity may be made, provided they are limited in scope and duration and must be reported.
“PPC is disappointed that the court adopted a sweeping operational injunction that will materially affect the region’s clean hydropower system and the millions of people who depend on it,” said Scott Simms, CEO and Executive Director of the Public Power Council.
“The Columbia River system already operates under some of the most protective fish measures in the nation, and public power utilities have invested billions of dollars over decades to support salmon recovery while producing reliable and affordable electricity,” he said.
“We appreciate that the court recognized the need for operational flexibility and declined to impose several far-reaching measures that are better addressed through long-term policy and congressional processes rather than a preliminary injunction,” Simms said.
The Public Power Council is a nonprofit association representing the interests of more than 100 consumer-owned electric utilities in Washington, Oregon, Idaho, Montana, Wyoming, and Nevada which collectively serve millions of electricity consumers.
PPC’s mission is to preserve and protect the benefits of the Federal Columbia River Power System for consumer-owned utilities, and is a forum to identify, discuss and build consensus around energy and utility issues.
The injunction comes after the Trump Administration issued a presidential memorandum and formally withdrew from the Columbia River System Memorandum of Understanding (MOU) in June of last year.
