Flood maps, also known as Flood Insurance Rate Maps, provided by the Federal Emergency Management Agency (FEMA) are a useful tool for assessing a property’s flood risk, and also are a factor in flood insurance and building requirements. Enter your address in the field below to determine your Flood Zone.
Flood zones and evacuation zones are different. Flood zones are areas mapped by FEMA for use in the National Flood Insurance Program. Evacuation zones are based on hurricane storm surge zones determined by the National Hurricane Center using ground elevation and the area’s vulnerability to storm surge from a hurricane.
- Zone A: The Special Flood Hazard Area (SFHA), except coastal V Zones, shown on a community's Flood Insurance Rate Map (FIRM). There are five types of A Zones:
- A : SFHA where no base flood elevation is provided.
- A#: Numbered A Zones (e.g., A7 or A14), SFHA where the FIRM shows a base flood elevation in relation to NAVD.
- AE : SFHA where base flood elevations are provided. AE Zone delineations are now used on new FIRMs instead of A# Zones.
- AO: SFHA with sheet flow, ponding, or shallow flooding. Base flood depths (feet above grade) are provided.
- AH: Shallow flooding SFHA. Base flood elevations in relation to NAVDare provided.
- Zone B: Area of moderate flood hazard, usually depicted on Flood Insurance Rate Maps as between the limits of the base and 500-year floods. B Zones are also used to designate base floodplains of little hazard, such as those with average depths of less than 1 foot.
- Zone C: Area of minimal flood hazard, usually depicted on Flood Insurance Rate Maps as above the 500-year flood level. B and C Zones may have flooding that does not meet the criteria to be mapped as a Special Flood Hazard Area, especially ponding and local drainage problems.
- Zone D: Area of undetermined but possible flood hazard.
- Zone V : The Special Flood Hazard Area subject to coastal high hazard flooding. There are three types of V Zones: V, V#, and VE, and they correspond to the A Zone designations.
- Zone X : Newer Flood Insurance Rate Maps show Zones B and C (see above) as Zone X.
Base Flood Elevation : The calculated measurement in feet above ground that has a one percent chance of being equaled or exceeded during a flood in any given year. This is the regulatory standard also referred to as the "100-year flood." The base flood is the national standard used by the National Flood Insurance Program (NFIP) and all Federal agencies for the purposes of requiring the purchase of flood insurance and regulating new development.
North American Vertical Datum (NAVD) : the national baseline elevation used by FEMA for determining flood elevation information.
If you think the flood map boundaries are incorrect, you can apply for a Letter of Map Amendment. This is a federal document that certifies that your home or property is not required to have flood insurance, because the primary structure and all attached areas (screen enclosures, garages, etc.), including the lowest adjacent grades, are out of the high-risk area.
For more information on the county’s flood maps, call the Hazard Mitigation Section of Public Works at (813) 635-5400 or Development Services at (813) 272-5600.