Upriver Dam Failure, Spokane River, 1986

Upriver Dam, in Spokane, Washington, failed in May 1986. The failure investigation report listed a number of contributing factors to the overtopping failure. Those included changes to the project that decreased the already inadequate freeboard, lack of understanding of the design basis of the project, and inadequate electrical/mechanical equipment and controls. Other factors included a perception that the Federal Energy Regulatory Commission (FERC) was the only dam safety program needed for project review, owner resistance to implementing FERC guidelines, and a lack of FERC guidance on electrical/mechanical issues. This paper discusses the event, the failure causes and lessons learned.