Many people are familiar with flooding due to heavy rainfall, but floods can occur in a number of different ways. Melting snow, a broken levee or dam and even powerful ocean waves hitting the shore have the ability to cause flooding. Floods can develop rapidly, or over a long period of time, and are the most common weather-related natural disaster.
Devastating and unpredictable, flash floods are the most dangerous types of floods. They are usually caused by excessive rainfall over a short period of time. The excess water sweeps through river beds and streets, collecting everything in its path. This type of flood can cause fast moving torrents, capable of carrying away cars and even homes. Areas with little to no vegetation can be especially vulnerable to flash floods because the excess water can’t be absorbed quickly enough to prevent flooding.
Other types of floods include river, coastal, inland and storm surge. The National Weather Service categorizes floods in in following ways:
- Minor Flooding — minimal or no property damage, but possibly some public threat or inconvenience.
- Moderate Flooding — some inundation of structures and roads near streams. Some evacuations of people and/or transfer of property to higher elevations are necessary.
- Major Flooding — extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations.