What is a floodplain?
In general, a floodplain is the flat area located adjacent to the main stream channel. When stream banks overflow during or after a storm, the floodplain provides natural storage for the excess water.
There are three distinct kinds or categories of floodplains in Fairfax County:
- Minor Floodplain: drainage area greater than 70 acres but less than 360 acres.
- Major Floodplain: drainage area 360 acres or greater.
- Those which are designated as a floodplain by the National Flood Insurance Program.
For further information about defining floodplains, please see the Zoning Ordinance, Article 20, Definitions.
Special Flood Hazard Areas
Special Flood Hazard Areas are high risk areas that have a one-percent chance of being inundated by a base flood in any given year as identified by the National Flood Insurance Program maps. Floodplain management regulations must be enforced and mandatory purchase of flood insurance applies for these areas. For more information, please visit FEMA's Special Flood Hazard Area website or see the Special Flood Hazard Area Maps.