A flood occurs when water inundates land that's normally dry, which can happen in a multitude of ways. Excessive rain, a ruptured dam or levee, rapid melting of snow or ice, or even an unfortunately placed beaver dam can overwhelm a river, spreading over the adjacent land, called a floodplain.

Flooding is a temporary overflow of water onto land that is normally dry. Floods are the most common natural disaster in the United States. 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.

USGS Flood Inundation Maps, along with Internet information regarding current stage from the USGS streamgage, provide emergency management personnel and residents with information that is critical for flood-response activities, such as evacuations and road closures, as well as for post-flood recovery efforts.

One area where river flooding really stands out is in the counties near the Red River along the border between northwest Minnesota and eastern North Dakota. The hilly terrain in the Appalachians...

Floods can affect any area to some degree; wherever rain falls, flooding can occur. As water falls to the Earth in the form of rain or snow, it seeps into the ground.

Flooding is an overflowing of water onto land that is normally dry. Floods can happen during heavy rains, when ocean waves come on shore, when snow melts too fast, or when dams or levees break. Flooding may happen with only a few inches of water, or it may cover a house to the rooftop.

During flooding. State and local response agencies are the primary responders for people who are concerned about or were affected by flooding. Find your state emergency office or agency from FEMA. Avoid contact with flood water due to potentially elevated levels of contamination associated with raw sewage and other hazardous or toxic substances that may be in the flood water.

Severe widespread flooding developed across much of the southern half of the Florida peninsula in every county. In the wake of the hurricane, approximately 90% of the eastern Florida peninsula south of Orlando was flooded.

Federal disasters were declared by the Federal Emergency Management Agency (FEMA) in 31 Texas counties. The heaviest rain areas met the criteria for a 500-year flood event. The highest known peak flows were recorded at 15 locations, including portions of the San Jacinto, Colorado, Lavaca, Guadalupe,...