Anywhere on Earth, a flood can occur. Floods are considered water accumulation in areas where land is normally dry. Floods are the most common natural disaster in the U.S. and can happen in any state. However, there are different types of floods that affect certain areas. An overrun river or stream can spill water over its banks. Heavy rainfall is another way flooding can occur. Classifications of floods include regional, flash and storm surge floods.
Coastal areas are prone to flooding due to rising water from the ocean or sea. Floods can occur from a storm that originates far away from the coast. Hurricanes or tropical storms, travelling across open water, can create huge waves that eventually reach the nearest coastline. Another way coastal floods can occur is when volcanoes or earthquakes happen underwater and create a tsunami. States that are likely to suffer from coastal floods include Alabama, Florida, Connecticut, Maine, Washington, Oregon, Texas, South Carolina, North Carolina, Boston, Rhode Island and other states that border an ocean or sea.
Flash floods, the number one weather-related killer, are common when dry or over-saturated soil is present. They come in the form of raging torrents that flow through river beds, city streets and mountainous canyons. The height of these torrents can be as high as 30 feet or more. Flash floods occurs within minutes or up to six hours after a severe rainfall. These type of floods originate from storms, breakage in dams and levees and even after ice storms. States that commonly have severe flash floods include Pennsylvania, Tennessee, Nebraska, Missouri, New York, Colorado, Ohio, Iowa, Illinois and other states that have mountainous or flat terrains.
Near Dams, Levees, Rivers and Streams
Floods can occur when rivers and streams run over their banks. Although made to prevent floods from happening, dams and levees that experience breakage can also cause flooding. Earthen dams are susceptible to breakage when the soil loosens. Levees, used to hold back large bodies of water, are historically known to suffer from excessive water spilling over the top. States including North Dakota, South Dakota, Wisconsin, West Virginia, Minnesota, New Jersey and Oklahoma are prime suspects of when water overflows dams, levees, rivers and streams.
Hurricanes, Tropical Storms and Other Storms
An average of 10 tropical storms happen in the U.S. each year and commonly hit coastal states the most. Tropical storms can produce torrential rain that can quickly fill storm drains and flood commercial and residential areas. Hurricanes feature high winds, severe rainfall and flying debris. Hurricanes and tropical storms can cause inland flooding hundreds of miles away from the coast. Heavy wind from tornadoes can push water up over river banks and streams. Rhode Island, Louisiana and Mississippi are common places where hurricanes and tropical storms cause flooding.
New Real Estate Developments
When large areas of residential and commercial property are constructed, it changes natural drainage environments and creates potential flood zones after a rainstorm. When water accumulates with nowhere to disperse, it begins to pool. Floods happen after new developments in major cities, low-lying areas, valleys, dry and humid environments and flat lands. States that may experience floods from new developments include Arkansas, Kentucky, Arizona, California and Virginia.