Dam Failure

Dam failures or levee breaches can occur with little warning, sometimes within hours - or less - of the first signs of structural concerns. Dams can fail for one or a combination of the following reasons:

  • Overtopping caused by floods that exceed the capacity of the dam
  • Structural failure of materials used in construction
  • Movement and/or failure of the foundation
  • Settlement and cracking of concrete or embankment
  • Piping and internal erosion of soil in embankment dams
  • Inadequate maintenance and upkeep
  • Deliberate acts of sabotage

Key Terms

  • A Flood Watch means there is a possibility of flooding or a flash flood watch.
  • A Flash Flood Watch means flash flooding is possible. Be prepared to move to higher ground. A flash flood can occur without any warning.
  • A Flood Warning means a flood is occurring or will likely occur soon. If you are advised to evacuate, do so immediately.
  • An Excluded Area (Zone X) on a FEMA flood map is an area that is protected by a dam or levee that would otherwise be in the Special Flood Hazard Area, or "100-year floodplain"; properties in excluded zones are not required to carry flood insurance to get a mortgage, but owners should strongly consider it regardless.
  • An Emergency Action Plan (EAP) is a formal document that identifies potential emergency conditions at a dam and specifies actions to be followed to minimize loss of life and property damage.

What to Do

  • Before (Preparedness / Mitigation)

    • Sign up online for Wayne County Alerts and have a battery or crank-powered NOAA weather radio available.
    • Decide early whether you will evacuate, and where you will go if ordered to leave.
    • Disconnect electrical appliances.
    • Know if your residence or business is in a floodplain or an "excluded area" that is protected by a dam or levee but would otherwise be within the Special Flood Hazard Area.
    • Apply for flood insurance, even if you may be in an "excluded area" or otherwise not be required to do so.
    • Learn First Aid.
    • Refer to Power Outage/Blackout and Medical Emergency Annexes.

  • During (Response)

    • If you encounter rising water, move to higher ground immediately.
    • Always stay clear from floodwaters.
    • Do not drive through flooded roads - "turn around, don't drown."
    • Stay away from downed power lines to avoid the risk of shock or electrocution.
    • Do not touch electrical equipment if you are wet or standing in water.

  • After (Recovery)

    • Return home when local officials say it is safe.
    • Avoid walking or driving through floodwaters.
    • Do not eat any food that may have come in contact with floodwater. If in doubt, throw it out.
    • Remove all porous items that have been wet for more than 48 hours and that cannot be cleaned and dried. These items can remain a source of mold growth and should be removed from the home.
    • Check-in with family and friends by texting or using social media.