The 50-Year Anniversary of the Kingsley Dam Wave Erosion Incident

On May 1st and May 2nd, 1972, a 30-hour windstorm battered and eroded the upstream face of the Kingsley Dam in western Nebraska. The erosion removed a significant amount of the upstream shell and led to the collapse of more than 400 feet (120 m) of the parapet wall running along the crest of the dam. The downstream town of Keystone was evacuated, and crews were summoned to lower the reservoir and begin emergency repairs. The failure of Kingsley Dam would have been the largest dam failure in U.S history, releasing 1.8 million acre-feet (2.2 km3) of water. The winds eventually subsided, and thankfully, the dam did not fail. Repairs were made and investigations were conducted. The incident was soon overshadowed by the failure of Canyon Lake Dam in South Dakota one month later. Fifty years after the incident, it is important to revisit the lessons that were learned, the warning signs that were missed, and the successful remedial measures and monitoring programs that were implemented after the incident.