Flood Zone Data – Overview & Interpretation
Each property may include:
- Flood Zone Code → Indicates the type and severity of flood risk
- Flood Zone (Boolean field) → Indicates whether flood data is available for that property
Important Distinction
1. Flood Zone (Boolean Field)
- Yes (True) → Flood zone data is available for this property
- No (False) → Flood zone data is not available
⚠️ Important:
A value of “Yes” does NOT mean the property is in a flood zone.
It only means we have flood zone information for that property.
2. Flood Zone Code
The Flood Zone Code determines the actual flood risk classification of the property.
Flood Zone Classifications
🟢 Low Risk Zones
These areas have minimal to moderate flood risk.
Code | Description |
|---|---|
B, X | Moderate flood hazard (between 100-year and 500-year flood levels). May include areas protected by levees or shallow flooding zones. |
C, X | Minimal flood hazard. Typically outside the 500-year flood zone. May still have minor drainage or ponding issues. |
🟠 High Risk Zones (Special Flood Hazard Areas)
These areas have a 1% annual chance of flooding (100-year floodplain).
Code | Description |
|---|---|
A | High risk area without detailed elevation data |
AE | High risk area with base flood elevations (BFE) provided |
A1–A30 | Legacy zones with BFE (older FEMA maps) |
AH | Shallow flooding (1–3 feet, ponding) |
AO | Shallow flooding (sheet flow, 1–3 feet) |
AR | Temporary flood risk due to flood control system construction |
A99 | Future protected area (flood control system in progress) |
🔴 Coastal & Very High Risk Zones
These areas include wave action and coastal flooding risks.
Code | Description |
|---|---|
V | Coastal flooding with wave hazards (no elevation data) |
VE, V1–V30 | Coastal flooding with wave hazards and base flood elevations |
⚪ Undetermined Risk
Code | Description |
|---|---|
D | Flood risk not determined (insufficient data) |
Key Takeaways
- Flood Zone = Yes → We have data
- Flood Zone Code → Determines actual flood risk
- Not all properties with flood data are high risk
- Always interpret the code, not just the boolean field
Example
Flood Zone | Flood Zone Code | Meaning |
|---|---|---|
Yes | X | Data available, low risk area |
Yes | AE | Data available, high flood risk |
No | — | No flood data available |