The U.S. Army Corps of Engineers, Portland District, issued a Notice of Intent to prepare a Supplemental Environmental Impact Statement (SEIS) for the Operation and Maintenance of the Willamette Valley System, a network of 13 multipurpose dams and reservoirs in Oregon. The SEIS responds to a 2024 Water Resources Development Act directive to formally analyze an alternative that would cease hydropower operations at the dams. The SEIS will also incorporate actions from the December 2024 NMFS Biological Opinion. Scoping comments are due June 6, 2025, and a draft SEIS is expected in Fall 2025.12