Emergency Action Planning



About EAPs

About EAPs

Fatal Statistics on Dam Failures

Contrary to popular belief:
Most dam failure fatalities are not the result of large dams.
Most fatalities are the result of small dam failures.

Dam failures resulting in fatalities:

  • 86% of the fatalities have resulted from dams between 20 and 49 feet in height
  • 47% of the fatalities have resulted from dams with a drainage area less than 2 square miles
  • 75% of the fatalities have resulted from dams with a drainage area less than 10 square miles. This describes 90% of Texas watershed dams and 80% of all Texas dams.
  • 7 dams had less than 300 acre-feet of reservoir storage area

Heavy rainfall can put sudden intense stress on dams:

  • The May 2004 failure of Callaway Dam near Hearne came after 15 inches of rain within 6 hours. No lives were lost.
  • Texas has had heavy spring rains each of the past several years

Failure of smaller dams in other states proved fatal:

  • Laurel Run Dam, Pennsylvania
    • Date: June 22, 1947
    • 42 foot high dam
    • 310 acre-feet storage volume
    • Failed at 2:35 a.m. July 20, 1977
    • 30 homes suffered major damage
    • 40 fatalities
  • Kelly Barnes Dam, Georgia
    • 40 foot high dam
    • 630 acre-feet storage volume
    • Failed 1:20 a.m. November 6, 1977
    • 9 homes, 18 trailers, 2 college dorms demolished
    • 39 dead
  • Timberlake Dam, Virginia
    • 33 foot high dam
    • 1,449 acre-feet storage volume
    • Failed 11 p.m. June 22, 1995
    • 2 fatalities
  • Koloko Dam, Hawaii
    • 44 foot high dam
    • 1,400 acre-feet storage volume
    • Failed 5:30 a.m. March 14, 2006
    • 7 fatalities

Wishful thinking vs. reality:

  • Owners do not think their dam is vulnerable
  • Downstream inundation and impact zones are much greater than thought
  • Good design, construction and maintenance does not always prevent failures
  • Problems develop because of unexpected occurrences

Regardless of the cause, the dam owner is always responsible and will normally be held liable

Factors Influencing Loss of Life from Dam Failures:

  • Number of people at risk
  • Flood depths and velocities
  • Time of day or time of year
  • Ease of Evacuation
  • Timeliness of warnings

Planning can reduce loss of life. An Emergency Action Plan helps dam owners, emergency responders, and the public understand and plan for what may happen during a breach under any of these circumstances.