The Rapid City Flood

On this date in 1972, the Rapid City flood devastated much of the South Dakota city. The disaster occurred after the Canyon Lake Dam failed in the wake of 10-15 inches of rain, sending a wall of water down the already swollen Rapid Creek at 10:45 p.m. Frantic evacuation orders were issued at 10:40 p.m., giving precious minutes for people to flee.

A total of 238 people died.

Canyon Lake is dammed once again and now the flood plain is a series of parks, golf courses and bike paths, which should minimize damage from future floods.

Nationally, the 1970s were the worst decade for flash floods in U.S. history. Devastating floods struck Buffalo Creek, WV (125 fatalities), Big Thompson Canyon, CO (145 fatalities), Johnstown, PA (76 fatalities), Toccoa Falls, GA (39 fatalities) and Kansas City, MO (23 fatalities), as well as the Rapid City Flood.

Flash floods killed an average of 127 people each year in the United States between 1972-2001. Improvements in forecasting and warning have been effective in reducing the death toll since then. No single flash flood has killed more than 100 people since 1980.

Between 1984-2013, that 30 year average dropped to 85 and the ten year average is now down to 75.

Category: Met 101/Weather History