Flooding is a temporary overflow of water onto land that is normally dry. Flooding can happen during heavy rains, when rivers overflow, when ocean waves come on the shore, when snow melts too fast, or when dams or levees break. Flooding may be only a few inches of water, or it may cover a house to the rooftop. Floods that happen very quickly are called flash floods. Floods are the most common natural disaster in the United States.
Failing to evacuate flooded areas or entering flood waters can lead to injury or death.
Floods may:
- Result from rain, snow, coastal storms, storm surges and overflows of dams and other water systems.
- Develop slowly or quickly. Flash floods can come with no warning.
- Cause outages, disrupt transportation, damage buildings and create landslides.