Spillway Chute Joints – the Devil’s in the Details

The Oroville Dam spillway chute failure provides difficult but clear lessons: past performance is no guarantee of future results, and routine inspections and rigorous dam safety programs may not be adequate to prevent a significant incident or even failure. There is a need to dig into the details of our dams and appurtenant structures, particularly older dams that may have been constructed prior to incorporation of practices that we consider standard today. Spillway chute and joint design is one instance where we need to dig deep into the design details, and if needed, perform explorations to verify assumptions.
The Oroville Dam Spillway Incident Independent Forensic Team (IFT) Report notes that there was no single root cause of the Oroville Dam spillway incident. Rather, the incident was caused by a “complex interaction of relatively common physical, human, organizational, and industry factors, starting with the design of the project and continuing until the incident.”