Flash floods are dangerously fast moving floods caused by a large amount of heavy rain in a localized area. This torrential downpour may transform a normally calm area into a powerful river of death in only a few short minutes. Many people are caught unprepared for the power and speed of a flash flood, which results in dangerous situations.
Flash floods are slightly different from normal floods. Normal floods involve water rising and overflowing from its normal path. However, flash floods appear quickly and move swiftly across land with little warning. Flash floods occur for a variety of reasons including concentrated rainfall during a slow moving thunderstorm, hurricanes, and tropical storms.
The most devastating flash floods are from dam and levee failures. When either structure breaks, an enormous amount of water is suddenly unleashed, destroying everything in its path.
The water in a flash flood moves at such a high velocity that it can move boulders, uproot trees, demolish buildings, and destroy bridges. The walls of water in such a flood and be anywhere from ten to twenty feet tall and usually carry a substantial amount of debris.