Citizens Action

Dam Failure

There are more than 87,350 dams in the United States, and at least 14,726 of them are High-Hazard Potential (HHP), according to the February 2013 National Inventory of Dams compiled by the U.S. Army Corps of Engineers (USACE) with data from state dam safety officials and other sources. More than 12,400 other dams are Significant-Hazard Potential (SHP) dams. HHP and SHP dams threaten lives and property if they fail.

Dam failure or levee breeches can occur with little warning. Intense storms may produce a flood in a few hours or even minutes for upstream locations. Flash floods occur within six hours of the beginning of heavy rainfall, and dam failure may occur within hours of the first signs of breaching. Other failures and breeches can take much longer to occur, from days to weeks, as a result of debris jams or the accumulation of melting snow.

What to Do before a Dam Failure

Knowing your risk, making sure an Emergency Action Plan (EAP) is in place, and evacuating when directed by emergency response officials are the most important steps you can take to stay safe from a dam failure. For information on how to prepare for a flood, visit  Before A Flood.