Flash floods occur within a few minutes or hours of excessive rainfall, a dam or levee failure, or a sudden release of water held by an ice jam. Flash floods can roll boulders, tear out trees, destroy buildings and bridges. Flash floods can also trigger catastrophic mudslides.
Flash floods are the number 1 weather-related killer in the United States.
National Weather Service
Staying current with forecasts from the National Weather Service can be an important part of flood preparedness. Individuals can purchase a NOAA weather radio to directly hear the forecasts, advisories, watches, and/or warnings. Some NOAA weather radios can alarm when there is a serious/dangerous weather condition. These radios are available at many stores.
The following terms may be used by the National Weather service:
A Flash Flood or Flood Watch means that flash flooding or flooding is possible within the designated watch area.
A Flash Flood or Flood Warning means that flash flooding or flooding has been reported or is imminent - take necessary steps at once.
An Urban and Small Stream Advisory means that flooding of small streams, streets and low-lying areas (such as railroad underpasses and urban storms drains) is occurring.
A Flash Flood or Flood Statement is follow-up information regarding a flash flood/flood event.
Find out if you live in a flood prone area. You can check with your local building department to see the flood maps for your municipality. If you are in a flood zone, purchase sufficient flood insurance. Flood losses are not covered under normal homeowner's insurance. Learn how your community would alert you if a flood was occurring or predicted.
Pre-assemble flood-fighting supplies like plastic sheeting, lumber, sandbags. Have check valves installed in building sewer traps to prevent flood waters from backing up in sewer drains.
As a last resort have large corks or stoppers to plug showers, tubs, or basins from water rising up through the pipes.
Flood Kit
Maintain a disaster supply kit at home. A kit will have (at minimum):
Monitor commercial radio, television, NOAA Weather radio or your Emergency Alerting Station for information
Be prepared to evacuate to higher ground if ordered to do so by authorities
Adhere to any emergency orders of authorities
Bring possessions inside the house or secure them
Do not touch any electrical appliances that are wet or standing in water
Avoid walking or driving through flood waters
Flood dangers do not end when the water begins to recede. Listen to a radio or television and do not return home until authorities indicate it is safe to do so.
Remember to help your neighbors who may require special assistance - infants, elderly people and people with disabilities.
If food or medicine has come in contact with flood waters, throw it out
Stay out of buildings if flood waters remain around the building
When entering buildings after a flood use extreme caution
Wear sturdy shoes and use battery-powered lanterns or flashlights when examining buildings
Examine walls, floors, doors, and windows to make sure that the building is not in danger of collapse
Watch out for animals, like snakes, that may have come into your home with flood waters
Take pictures of the damage - both of the house and its contents for insurance claims
Look for fire hazards
Broken or leaking gas lines
Flooded electrical circuits
Submerged furnaces or electrical appliances
Flammable or explosive materials coming from upstream
Report potential emergencies to authorities
It's best to have a professional pump out a basement, to avoid further structural damage. FEMA recommends pumping out about one-third of the water per day