June 5, 2001
Ken Pedde, Acting Regional Director
US Bureau of Reclamation
The Failure of Teton Dam
June 5, 1976. Teton Dam. These words bring back memories for people throughout the West, but none so vivid as those in eastern Idaho.
Twenty-five years ago a new dam, designed and built by the Bureau of Reclamation to provide flood control and supplemental irrigation water in eastern Idaho, failed. And with the failure, the lives of downstream residents were irrevocably changed. When the billions of gallons of water were suddenly released, fourteen lives were lost and hundreds of millions of dollars in property damage occurred.
After this day an agency also changed. On the anniversary of this terrible event, I’d like to reflect on what happened and what Reclamation has done so this doesn’t happen again.
Following the dam failure, two investigation groups were formed - a Department of Interior team and an independent panel of respected engineers, geologists, and dam safety professionals. Both efforts were supported, wholeheartedly, by Reclamation. Scores of eyewitnesses, contractors, and Reclamation design and construction personnel were interviewed. Onsite forensic studies were conducted, and all correspondence and records were extensively reviewed. These technical findings identified a number of contributing factors but no single cause for the failure of Teton Dam.
But lessons were learned, and changes were made. These included procedural details like implementing independent peer review of studies for dams, design changes like ensuring redundant measures to control seepage and prevent piping, special treatment for fractured rock foundations, and frequent site visits during construction by the design engineers.
Largely because of Teton, the Administration took action to require each Federal agency to review their dam safety activities and to strengthen their dam safety programs, and Congress passed several acts authorizing a National dam safety program.
Reclamation now has in place several programs that result in an overall assurance of safe structures. Reclamation dams are inspected annually and in more detail every 3 years, with a comprehensive evaluation of dam performance under various loading conditions every 6 years. Instrumentation devices have been installed at dams to monitor their functioning in ways that visual inspections cannot.
The Reclamation Safety of Dams Act of 1978 provided funds to analyze and modify structures determined to be potentially unsafe. Some thirteen dams in the Pacific Northwest Region have been modified in this program, continuing their benefits safely to future generations.
In addition, Reclamation’s emergency planning ensures emergency procedures are developed and written down and that responsible staff are trained in using them. These procedures include regular exercises and coordination with local emergency management officials. Inundation maps showing floodwater travel time estimates serve as additional tools to aid local entities in their preparations and development of local emergency plans.
The lessons learned from the Teton Dam failure are used by Reclamation engineers to train examiners, designers, construction specialists, and dam operators within Reclamation and other agencies.
The memory of the devastation that followed the failure of Teton Dam is a part of Reclamation’s institutional history. On this somber anniversary, we pay tribute to the spirit and resilience of the people of eastern Idaho who rebuilt their lives. And we pledge to never forget.