According to the National Severe Storms Laboratory,
“Flooding accounts for or is involved with three quarters of Federal Disaster declarations. Floods generally claim about 140 lives each year, making them the most deadly kind of weather in the U.S. They are also responsible for more damage to property each year than any other type of weather hazard.”
Most flood deaths are due to flash floods. The difference between flooding and flash flooding is that flooding is a long-term event lasting a week or more, whereas flash flooding occurs within six hours of the rain event.
Several factors contribute to flash flooding. The two main factors are the rate of rainfall and how long the rain lasts. Other factors are topography, soil conditions, and ground cover. Flash floods occur within a few minutes or hours of heavy rainfall, a dam or levee failure, or a sudden release of water by an ice jam. Most flash flooding is caused by slow-moving thunderstorms, more than one thunderstorm moving over the same area, or heavy rains from hurricanes and tropical storms.
When you receive a Flood Warning
If advised to evacuate, do so immediately—before access is cut off by flood water. It is a good idea to make a plan on where to go with several options such as a friend’s home, a motel in another town, or a shelter. You need to get to higher ground.
Don’t drive over a flooded road! Turn around and go another way. The depth of the water is not always obvious. The road bed may be washed out under the water. Nearly half of all flash flood deaths are auto related.
If your vehicle stalls, leave it and seek higher ground.
Don’t allow children to play near high water, storm drains, or viaducts.
Don’t camp or park your vehicle along streams, especially during threatening conditions.
Be very careful at night when it is harder to recognize flood dangers.
Don’t go in a flooded basement. You may get electrocuted if the water has reached the electrical outlets.
Flooding can occur nationwide. Be prepared and stay informed about the weather by listening to a television or radio.