Flood zone designations
FEMA's Flood Insurance Rate Maps divide communities into flood zones. Zones beginning with A or V form the Special Flood Hazard Area (SFHA) — the area mapped as subject to the 1-percent-annual-chance flood event — where the federal mandatory purchase rule can apply to mortgaged buildings. Zones X and D lie outside the SFHA. Each page below describes one designation from FEMA's published definitions.
Special Flood Hazard Area zones
- AE Zone AE is a Special Flood Hazard Area where FEMA has completed a detailed study and published base flood elevations.
- A Zone A is a Special Flood Hazard Area mapped by approximate methods, without published base flood elevations.
- AH Zone AH is a Special Flood Hazard Area subject to shallow ponding, with average depths of one to three feet.
- AO Zone AO is a Special Flood Hazard Area subject to shallow sheet-flow flooding on sloping terrain, with average depths of one to three feet.
- AR Zone AR is a Special Flood Hazard Area that results from the decertification of a flood control system that is being restored.
- A99 Zone A99 is a Special Flood Hazard Area that is to be protected by a federal flood protection system under construction.
- V Zone V is a coastal Special Flood Hazard Area with additional hazards from storm-induced wave action, mapped without base flood elevations.
- VE Zone VE is a coastal Special Flood Hazard Area with wave hazards where base flood elevations have been determined.
Zones outside the SFHA
- X Zone X covers areas outside the Special Flood Hazard Area, mapped as moderate (shaded X) or minimal (unshaded X) flood hazard.
- D Zone D marks areas where flood hazards are undetermined because no analysis has been conducted.
To see which zones the insured properties of a specific ZIP code fall into, use the ZIP lookup tool or browse states.