The Rapid City Flood of 1972
Flood Comparisons
Flooding causes more damage in the United States than any other weather related event...an average of $3.6 billion a year. Flash floods are the most deadly natural disaster. The June 1972 flash flood in Rapid City caused 238 deaths and over $100 million in damage. How do other notable floods compare to the Rapid City Flood?
| Date | Location | Cause | Damage | Deaths |
| 06/10/1972 | Rapid City, SD | Flash flood | $165 million | 238 |
| 05/31/1889 | Johnstown, PA | Dam break | 2,200 | |
| 07/31/1976 | Big Thompson Canyon, CO | Flash flood | $40 million | 145 |
| 02/26/1972 | Buffalo Creek, WV | Dam break | 118 | |
| 05-09/1993 | Portions of IL, IA, KS, MN, MO, NE, ND, SD and WI along the Missouri and Mississippi Rivers | River flood | $15 billion | 50 |
| 06/14/1990 | Shadyside, OH | Flash flood | $8 million | 26 |
| 12/1991 to 01/1992 | South central Texas | River flood | $100 million | 15 |
| 08/01/1985 | Cheyenne, WY | Flash flood | $61 million | 12 |
Types of Flooding
Although there are different types of flooding, the common element is the underlying soil cannot absorb water fast enough.
River flooding is generally caused by widespread, heavy rain. It may also be caused by a combination of rainfall and melting snow.
Flash floods are primarily caused by intense rainfall, especially in mountainous terrain and urban areas where more runoff occurs.
Ice jam floods occur in the spring, when ice on the rivers begins melting and chunks of ice jam at bends in the river and near bridge abutments. The ice acts as a dam, causing water to back up behind it. Occasionally, the ice will move downstream quickly and destroy bridges and other property in its path.
Snow melt floods are another spring flood producer. Typically, snow melts slowly enough that it doesn’t cause problems. However, when heavy rain falls over a snow pack, rapid melting occurs.
Hurricane/Tropical Storm floods are a danger in coastal areas, where most hurricane-related deaths are due to either the storm surge or inland flooding. A storm surge is water pushed toward the coastline by the winds in a hurricane or tropical storm. Inland flooding often occurs when weaker storms drift slowly or stall over an area.
