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FloodsAccording to the National Weather Service, flash flooding is the No. 1 weather-related killer in the U.S., costing an average of $3.7 billion annually. FEMA cites flooding as the cause of 90 percent of all natural disaster damage, excluding drought.
While some areas of Virginia are particularly vulnerable to floods, the truth is that flooding can happen anytime, anywhere. For this reason, it’s imperative that businesses prepare ahead of time to keep their employees and workplaces safe in flood conditions.
A flash flood is a rapidly rising and rapidly flowing surge of water that results from runoff from excessive rainfall or the failure of a dam or levee. While some floods might take several hours or days to develop, a flash flood may take only minutes, making flash floods particularly dangerous. Flash floods most often occur within a few minutes or hours of excessive rainfall, but might also be the result of a dam or levee failure or a sudden release of water held by an ice jam. They can destroy bridges, severely damage buildings, move boulders, wash away automobiles and cause mudslides.
Two key elements contribute to the condition known as flash flooding: rainfall intensity and duration. Topography (the physical characteristics of the land, such as hills and valleys), soil conditions and ground cover also play an important role. Most flash flooding, however, is due to slow-moving thunderstorms. Heavy rains from hurricanes and tropical storms are also common causes of flash flooding.
During periods of heavy rainfall or after severe winter storms, it’s important to listen to a weather radio or your local radio or TV stations for flood information. Make sure you’re familiar with the following terminology.
Read about responding to floods.
