The Risks of Aging Dams Modern dams, while engineering marvels providing water and power, pose significant risks as they age. Many U.S. dams were designed to last 50 years; a quarter have exceeded this lifespan with one in ten considered life-threatening due to structural deficiencies. Failures can lead to catastrophic floods that devastate communities downstream.
Historical Lessons from Johnstown Flood In 1889, the poorly maintained South Fork Dam near Johnstown failed after heavy rains caused overtopping. The resulting flood killed over 2,200 people and obliterated towns below it within minutes—a stark reminder of the consequences of neglecting dam safety measures.
Earthquake Threats Amplify Dam Vulnerabilities Many older dams were built without accounting for seismic activity or landslides now known to threaten their integrity during earthquakes. For example, an earthquake could trigger landslides into reservoirs like Hills Creek in Oregon—potentially breaching its embankment and endangering hundreds of thousands downstream.