A Special Flood Hazard Area (SFHA) is the official FEMA term for high-risk land — and it is the single most important thing to know when you are deciding about flood insurance.
The short answer
An SFHA is any area FEMA maps as having at least a 1% chance of flooding in any given year (the “100-year flood”). On the Flood Insurance Rate Map (FIRM) these are the zones that start with A (inland/riverine) or V (coastal, with wave action). If your building is in an SFHA and you have a federally backed mortgage, flood insurance is mandatory.
Which zones are SFHAs?
| In the SFHA (high-risk) | Not in the SFHA |
|---|---|
| A, AE, AH, AO, AR, A99 | X shaded (0.2% / 500-year) |
| V, VE (coastal) | X unshaded (minimal), D (undetermined) |
The “100-year flood” is misleading
A 1%-annual-chance flood does not happen once a century. Over the life of a 30-year mortgage, a home in an SFHA has roughly a 26% chance of being flooded — far higher than the chance of a fire. That is why the mandatory-purchase requirement exists.
Base Flood Elevation (BFE)
Many SFHAs (like Zone AE) come with a Base Flood Elevation — the height floodwater is expected to reach in the 1% flood. Building above the BFE is one of the biggest levers on your premium under Risk Rating 2.0.
What to do next
Check your address on FEMA’s Flood Map Service Center to confirm your zone, then see whether you need a policy and what it costs in your state. General information only — not insurance advice.