Columbia River System Operations and the Future of the Lower Snake River Dams

Congress has repeatedly debated how to operate and allocate resources from federal water resources projects—such as multipurpose federal dams—to serve various human needs while protecting or conserving species listed under the Endangered Species Act (ESA; 16 U.S.C. §§1531-1544). The Columbia River Basin, which includes the Snake River, is home to numerous federal and nonfederal dams that provide an array of services within the basin and whose operations affect certain fish species. Four dams on the Lower Snake River that are owned and operated by the U.S. Army Corps of Engineers are a focal point for these debates. The Columbia River Basin supports anadromous salmon and steelhead trout populations, many of which are now listed as endangered or threatened under the ESA. Four of these listed populations inhabit the Snake River watershed, a subbasin that encompasses over 40% of the larger Columbia River Basin. Federal courts have recognized that certain fish populations in the Columbia River Basin have economic and religious importance to local Tribes, and the federal government has acted to establish and protect the treaty fishing rights of Tribes occupying the Columbia River Basin. Despite federal and nonfederal efforts to protect and recover fish populations through actions such as altered dam operations and habitat-focused initiatives, listed salmon and steelhead trout populations remain low in the Columbia River Basin. Due to the potential effects on listed species from operating federally owned Columbia River Basin dams, federal agencies operating these dams have consulted with the National Marine Fisheries Service under the ESA since the mid-1990s regarding agency plans for dam operations. Stakeholders have repeatedly sued the federal government over the resulting biological opinions and decision documents. Much of the litigation has centered on whether the federal agencies have properly justified their operational plans in light of alternative actions that some argue would better protect listed species. Debate has included whether the federal agencies should evaluate the alternative of breaching one or more of the four Lower Snake River dams. Consistent with a federal court directive, the federal agencies considered removal of the dams as one course of action in a 2020 environmental impact statement (EIS). This option was not selected for implementation. Rather, in a 2020 record of decision (ROD), the agencies selected an alternative approach that retains the dams and increases the flow at certain times through several of the dams in the system to benefit migrating fish. In response to the 2020 ROD, the plaintiffs in the ongoing litigation added claims related to the 2020 biological opinion (BiOp), environmental impact statement, and ROD. The litigation was stayed in October 2021 to allow for settlement negotiations. During the stay, in September 2023, President Biden signed a presidential memorandum directing federal agencies to prioritize their authorities and available resources to advance the restoration of native fish populations in the Columbia River Basin. On February 8, 2024, the court granted certain parties’ request to stay the litigation through 2028 to allow them to implement a memorandum of understanding (MOU), which they submitted with the motion to stay. The MOU stated that the federal government agreed to implement commitments, consistent with the 2023 presidential memorandum, in support of a restoration plan known as the Columbia Basin Restoration Initiative that was developed by four Tribes and two states. The MOU also committed the federal government to 10-year interim operations of the dams to balance fish and energy needs. On June 12, 2025, President Trump issued a memorandum directing the heads of federal agencies to take all appropriate steps to withdraw from the MOU, among other actions. On September 11, 2025, the plaintiffs filed a motion to lift the stay and resume litigation, which the court granted. Accordingly, the litigation over the 2020 BiOp, EIS, and ROD resumed. Legislative options regarding federal dam operations in the Columbia River Basin and the lower Snake River include whether to continue or alter dam operations and whether to remove the lower Snake River dams. Some Members of Congress have proposed legislative options that would address these issues in recent Congresses. These proposals and other options typically entail tradeoffs between the benefits that the dams currently provide and the recovery of ESA-listed fish populations, among other issues. Significant uncertainty remains as to the potential effects and costs of most options under consideration. For example, estimates of the cost to replace existing benefits provided by the lower Snake River dams have ranged from $10 billion to $31 billion, mostly for electricity generation and grid services. Congress’s preferred course on how to address Columbia River System operations, including the lower Snake River dams, may also impact the solutions considered for other similarly situated federal projects and listed species habitats.