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 14,726 High-Hazard Potential (HHP) dams in the U.S. 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.

Of those 14,726 HHP dams, 3,172 dams do not have Emergency Action Plans to guide emergency response. Another 2,700 HHP dams 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 more than 7,170 dams, of which 1,083 are HHP dams and 690 are Significant-Hazard Potential (SHP) dams, all classified as putting human lives at risk. As of October 2013, more than 800 of the HHP dams and 396 SHP dams had EAPs. The state Legislature permanently exempted 210 SHP dams from EAP requirements.

Source: National Inventory of Dams, February 2013 and the Texas Commission on Environmental Quality


North Carolina has 5,647 dams, of which 3,684 are state-regulated and 1,337 are HHP. Of those HHP dams, 875 do not have an EAP and current state law does not require them to have EAPs.

Source: North Carolina Department of Environment and Natural Resources Inventory of Dams September 2013.

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 685 dams, 468 of which are HHP, and of those only 271 have EAPs as of October 2013.

Source: Missouri Department of Natural Resources.