Case Study: Kingsley Dam (Nebraska. 1972)

Kingsley Dam is located on the North Platte River in western Nebraska.  At 163 feet (50 m) tall and over three miles long, it is the largest dam in Nebraska.  On May 1st and 2nd, 1972, a 30-hour windstorm battered and eroded the upstream face of the dam. After breaking through the upstream wave protection, waves removed large portions of the upstream shell, eventually leading to the collapse of more than 400 feet (120 m) of the parapet wall along the crest of the dam. Fearing the dam would fail, residents in the downstream town of Keystone evacuated their homes and headed for higher ground.  Crews were immediately summoned to lower the reservoir and begin emergency repairs. Though the winds eventually subsided, and the dam ultimately did not fail, the incident highlights the significant damage a prolonged windstorm can inflict on an earthen dam.