There are several different kinds of floods in addition to the four discussed previously.
Flash Flooding occurs when a sudden, heavy rain event occurs. When this happens and the ground cannot absorb the water as quickly as it falls, flash flooding occurs. While flash floods happen and subside quickly, they are fast-moving, this makes being swept away very easy. Fast-moving debris also becomes dangerous water-guided missiles.
Drain and Sewer Flooding happens when water management systems are overfilled with water or blocked and cause water to back up systems. These types of floods won't necessarily depend on rainfall. Blockages can occur internally and cause the system to overflow.
Reservoir Flooding occurs when dams or other means of water holding fail or overflow and cause flooding. While this type of flooding is rare, it is possible. So, be prepared by having flood insurance to protect your home or business and an Emergency Action Plan (EAP) in place.
According to FEMA, approximately 15,000 dams in the United States are classified as high-hazard potential (HHP), which means their failure could result in loss of life. Dams can fail for a number of reasons, including overflowing caused by floods, acts of sabotage, or structural failure of materials used in dam construction.
About 27,000 dams throughout the U.S. could incur damage or fail, resulting in significant property damage, lifeline disruption (utilities), business disruption, displacement of families from their homes, and environmental damage.
Consider other water-holding means as well, like levees and floodwalls.