Teton Dam: The Dam That Failed Its First Fill

On a Saturday morning in June 1976, the newest dam in the Bureau of Reclamation's system failed during its first filling. The Teton Dam was three hundred and five feet tall, held a reservoir seventeen miles long, and had never successfully stored water. It was the first dam the Bureau ever lost. Eleven people died, thousands lost their homes, and the dam was never rebuilt. I'm a licensed professional engineer, and I spent two days at the dam site and in the communities downstream: the breach overlook, the forensic cross-section through the dam's core, downtown Rexburg, and the Menan Buttes, where the floodwater split around two volcanic cones that have stood on the Snake River Plain since the last ice age. This episode is the engineering story of why the dam failed. It became, along the way, a remembrance of the people it took. We name all eleven. CHAPTERS 0:00 Cold Open 1:05 Teton River 2:13 The Design 3:17 In the field 5:58 Piping Failure 7:01 Chronology 11:17 Menan Buttes 11:50 The Flood 12:34 The Eleven 16:49 Rexburg 18:19 Accountability 20:15 Fontenelle 20:38 Conclusion 21:37 Outro 22:29 Remembrance A NOTE ON THE ANNIVERSARY For the fiftieth anniversary, The Teton Letters project set survivor accounts from the 1977 Teton Oral History Program to music: songs built from the stories of families in Sugar City, Rexburg, Wilford, and Roberts. If this episode stays with you, their work is worth your time: https://tetonletters.substack.com/p/t... IMAGERY Thumbnail and archival aerial photography of the June 5, 1976 failure: U.S. Bureau of Reclamation, public domain. All field footage, drone photography, maps, and graphics are my own. Satellite imagery: Copernicus Sentinel and NASA Earth Observatory. SOURCES Failure of Teton Dam: Report of the Independent Panel to Review Cause of Teton Dam Failure, U.S. Department of the Interior, December 1976 Interior Review Group Report, 1977 Eric A. Stene, The Teton Basin Project, Bureau of Reclamation History Program J. David Rogers, Retrospective on the Failure of Teton Dam, Missouri University of Science and Technology R.L. Wiltshire, 100 Years of Embankment Dam Design and Construction in the U.S. Bureau of Reclamation, 2002 Wayne J. Graham, The Teton Dam Failure: An Effective Warning and Evacuation Fatality records: Idaho East, The Teton Dam Flood, Winter 1977 Museum of Rexburg, Just Add Water exhibit, Rexburg City Hall Teton Oral History Program, 1977, BYU-Idaho Special Collections If you or someone you know is struggling, help is available. In the United States, you can call or text 988 to reach the Suicide and Crisis Lifeline. The Hydraulic Record covers infrastructure failures from an engineering perspective: what broke, how it broke, and who made the decisions that led to it.