Flood Zones: Altadena vs Santa Monica
How do flood zones rules compare between Altadena, CA and Santa Monica, CA?
Altadena and Santa Monica have similar restriction levels.
Altadena, CA
Los Angeles County
Most of Altadena is in FEMA Flood Zone X (minimal hazard), but the area along Eaton Wash, the Arroyo Seco tributaries, and post-Eaton Fire burn-scar areas have heightened flood and debris-flow risk. LA County Code Ch. 22.142 (Floodplain Management) applies in mapped Special Flood Hazard Areas.
View full Altadena rules →Santa Monica, CA
Los Angeles County
Santa Monica participates in the National Flood Insurance Program and has adopted floodplain management regulations for coastal areas designated as FEMA Zone A. The Director of Public Works serves as floodplain administrator. Sea level rise poses an increasing coastal flood risk to the City.
View full Santa Monica rules →Key Facts Comparison
| Fact | Altadena | Santa Monica |
|---|---|---|
| Most of Altadena | Zone X (minimal hazard) | - |
| Eaton Wash Adjacent | Zone A / AE possible | - |
| Code Section | LA County Code Ch. 22.142 | - |
| BFE+1 Required | In SFHA | - |
| Post-Eaton Fire | Elevated debris-flow risk | - |
| Coastal Zone | - | FEMA Zone A |
| Most of City | - | Zone X (minimal risk) |
| Administrator | - | Director of Public Works |
| Flood Maps | - | msc.fema.gov |
Highlighted rows indicate differences between cities.
Altadena FAQ
Is Altadena in a flood zone?
Most of Altadena is in FEMA Zone X (minimal hazard), but areas along Eaton Wash and the foothill channels can be in Zone A/AE. Check the FEMA Map Service Center for your specific parcel.
Did the Eaton Fire affect flood risk?
Yes — post-fire burn scar areas above Altadena have elevated debris-flow and flash-flood risk during winter storms. USGS and NWS issue post-fire debris-flow advisories.
Santa Monica FAQ
Is Santa Monica in a flood zone?
Coastal areas along the shoreline carry FEMA Zone A designations. Most of the City is Zone X (minimal flood risk). Check msc.fema.gov or the City's GIS flood hazard zone viewer for your specific property.
Is sea level rise a concern in Santa Monica?
Yes. Studies project increasing coastal flooding from climate-driven sea level rise. The City's General Plan includes adaptation strategies, and the floodplain ordinance applies special standards to coastal construction.
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