Department of Emergency Management and Security

CONTACT INFORMATION: Open during regular business hours 8 a.m. - 4:30p.m., Monday - Friday
4890 Alliance Drive, Suite 2200, Fairfax, VA 22030
Seamus Mooney
Coordinator

Dam Failure

What It Is

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

Department Resources

Related Resources

Dam Hazard Annex

 

Dam Failure Hazard Annex

Click on the appropriate link below to download a PDF copy of the Dam Failure Hazard Annex page from the Community Emergency Response Guide.

English (PDF) | Spanish (PDF) | Korean (PDF) | Arabic (PDF) | Mandarin (PDF) | Vietnamese (PDF)

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

  • Sign up for Fairfax 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.

  • 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.

  • 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 flood water. 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.

The information contained on this webpage was pulled from the Community Emergency Response Guide.  More information about this topic may be found by clicking the link below.

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