FEMA flood zones explained
FEMA's Flood Insurance Rate Maps sort land into zones by flood risk. High-risk zones are called Special Flood Hazard Areas (SFHAs). If a building in an SFHA has a mortgage from a federally regulated or insured lender, flood insurance is required.
| Zone | Risk | What it means |
|---|---|---|
| A | High (SFHA) | 1% annual chance flood area where FEMA has not published a base flood elevation (BFE). |
| AE (A1–A30) | High (SFHA) | 1% annual chance flood area with a published BFE: the height the 100-year flood is expected to reach. |
| AH | High (SFHA) | Shallow ponding, usually 1 to 3 ft deep, with a BFE. |
| AO | High (SFHA) | Shallow sheet flow on sloping ground, usually 1 to 3 ft; FEMA publishes a depth instead of a BFE. |
| AR / A99 | High (SFHA) | Areas where a flood-control system (such as a levee) is being restored or built. |
| VE / V | High, coastal | Coastal high-hazard area with storm-surge wave action of 3 ft or more. Stricter building rules apply. |
| X (shaded) / B | Moderate | 0.2% annual chance (500-year) flood area, or 1% areas with average depths under 1 ft or behind certified levees. |
| X (unshaded) / C | Minimal (mapped) | Outside the 0.2% annual chance flood area. Flooding from heavy rain and poor drainage is still possible. |
| D | Undetermined | Possible but unstudied flood hazard. |
What's a base flood elevation?
The BFE is the water surface height of the 1% annual chance flood, measured against a vertical datum (usually NAVD88, sometimes the older NGVD29). Comparing the building's lowest floor with the BFE is what drives flood insurance pricing and building rules. An Elevation Certificate from a licensed surveyor measures it.
What does 1% a year really mean?
A 1% annual chance adds up to roughly a 26% chance of at least one such flood over a 30-year mortgage. A 0.2% annual chance adds up to about 6%.
Florida flood disclosure
Since October 1, 2025, Florida sellers of residential property must give buyers a separate flood disclosure at or before contract, covering known flood damage, flood insurance claims and federal flood assistance during ownership (Fla. Stat. 689.302). Landlords must give a similar disclosure before signing residential leases of one year or longer (Fla. Stat. 83.512). This is general information, not legal advice.
Sources: FEMA Flood Zones glossary and NFIP Flood Insurance Manual; Florida Statutes. Information only, not legal or insurance advice.