Most communities in the United States can experience some kind of flooding after spring rains, heavy thunderstorms, or winter snow thaws.
Floods can be slow, or fast rising but generally develop over a period of days.
Dam failures are potentially the worst flood events. A dam failure is usually the result of neglect, poor design, or structural damage caused by a major event such as an earthquake. When a dam fails, a gigantic quantity of water is suddenly let loose downstream, destroying anything in its path. Flash floods usually result from intense storms dropping large amounts of rain within a brief period. Flash floods occur with little or no warning and can reach full peak in only a few minutes.