To prohibit the Secretary of the Army from carrying out certain spillage operations on the Lower Snake Rivers dams, and for other purposes.

HR 8157 prohibits the U.S. Army Corps of Engineers (via the Secretary of the Army) from conducting spillage operations (releasing water through spillways) at four specific Lower Snake River dams - Ice Harbor, Lower Monumental, Little Goose, and Lower Granite - without prior approval from both the Secretary of the Army and the Bonneville Power Administration. This requires the Army and Bonneville to jointly consider all Columbia River System operations before approving such activities. The bill directly affects dam management decisions related to water flow, which impacts fish migration (particularly salmon), power generation, and river operations. It does not change existing dam operations but adds a formal approval step for spillage.