Risk based procedure for managing a spillway gate testing program for dam safety

The Tennessee Valley Authority owns and operates fifty- four dams in a seven state region. The operation of discharge outlets to effectively release stored flood water is necessary to provide adequate safety measures for dams. Dams store a large volume of water behind the structure. Many dams are multifunctional and include flood control as one of the tasks. To ensure that spillway gates operate as close to 100% reliability as possible, a program must be implemented that requires periodic inspections and actual operational testing.

National recommended testing programs are reviewed to determine related guidelines and criteria to produce dependable outlet devices. The current TVA testing method is also discussed. Downstream damage and loss of water are the two main concerns for upgrading a spillway testing program to implement operating conditions into an inspection. Risk analysis is utilized to demonstrate that an increased testing program will not only benefit the reliability of spillway gates to pass water but also benefit TVA by lowering maintenance costs by detecting problems earlier and reducing spillway gate inoperability.