Dams classified as High-Hazard Potential (HHP)
are those where failure or mis-operation will probably
cause loss of human life.

There are at least 13,859 High-Hazard Potential (HHP) dams in the U.S. according to the 2009 National Inventory of Dams compiled by the U.S. Army Corps of Engineers (USACE) with data from state dam safety officials and other sources.

Of those 13,859 HHP dams, 3,153 dams do not have Emergency Action Plans to guide emergency response. An equal number are not required to have an EAP, primarily because they fall outside state laws and regulations that often are inadequate to properly safeguard public health and safety in the event of a dam breach.

Learn more about the dam safety and EAP regulations in these states. If you are a dam owner, you can find out how to complete an EAP. And if you are a citizen who may be at risk, learn how you can become involved in helping get more EAPs completed.

Texas has 7,170 dams, of which 1,730 are classified as putting human lives at risk. As of January 1, 2011, over 700 of the dams had EAPs, and there were 552 requests for more time to comply on other dams. Texas regulations specified that all 1,730 dams have EAPs or time extensions by January 1. Owners of more than 400 dams are now in violation of the regulations.

Source: National Inventory of Dams, 2009

North Carolina has 4,627 state-regulated dams, of which 1,129 are HHP. Of those HHP dams, 300 have EAPs. Current state law does not require the needed EAPs on more than 800 other HHP dams.

Source: North Carolina Department of Environment and Natural Resources

Missouri has 5,099 dams, of which 1,588 are HHP, and of those 1,072 are not required by state law to have an EAP. State regulations cover only 674 dams, 482 of which are HHP, and of those only 87 have EAPs as of February 2011.

Source: Missouri Department of Natural Resources.