Columbia-Pacific Northwest Region

American Falls Concrete Spillway Rehabilitation Project

Project Need

The scheduled work will improve the structural integrity of the American Falls Dam spillway and stilling basin to avoid further deterioration and to provide a more feasible means of access for future maintenance activities. Minor repairs have been completed to the spillway face throughout its lifetime, including an overlay of the stilling basin floor that was completed in 1978 to repair damaged concrete after the initial spill season. However, over the ensuing 44 years of service, these structures have experienced ongoing deterioration. The planned construction activities will address these issues.