Office of Emergency Management
Riverine or Fluvial Flooding is caused by the water in rivers over time rising beyond the capacity of the river or streambed and overflowing its banks. Riverine flooding is typically caused by extended periods of rain, heavy snowmelt, or due to ice dams.
Flash Floods are caused by sudden, locally heavy rainfall, causing a rapid increase in river or surface water, accompanied by swift currents. Flash floods can be difficult to predict due to their sudden, locally concentrated rainfall.
Pluvial / Urban / Surface Flooding
Surface flooding is caused by the local drainage being overwhelmed by local rainfall, causing pools of water to spread in areas away from rivers.
- Shallow moving water can sweep pedestrians off their feet
- Vehicles can be stalled, stranded, or swept away when crossing water
- Water depth is hard to judge, and the consequences of a misjudgement can be fatal
- Floods are the most common natural disaster in the United States and cause an average of $54 billion in damage per year
- DHS Ready.gov Flood Info
- FEMA Flood Maps