Flood Zones: Altadena vs Pomona
How do flood zones rules compare between Altadena, CA and Pomona, CA?
Altadena and Pomona 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 →Pomona, CA
Los Angeles County
Portions of Pomona fall within FEMA-designated flood zones, primarily along drainage channels. The city participates in the National Flood Insurance Program (NFIP) and requires compliance with floodplain development standards.
View full Pomona rules →Key Facts Comparison
| Fact | Altadena | Pomona |
|---|---|---|
| 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 | - |
| NFIP Participant | - | Yes |
| Flood Maps | - | FEMA Flood Map Service Center |
| Building Code | - | CA Building Code floodplain provisions |
| Dept. | - | Water Resources Department |
| Stormwater | - | (909) 620-3654 |
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.
Pomona FAQ
Is my Pomona property in a flood zone?
Check FEMA's Flood Map Service Center at msc.fema.gov for your property's flood zone designation. The city's Water Resources Department can also assist.
Do I need flood insurance in Pomona?
Properties in FEMA-designated Special Flood Hazard Areas are required to carry flood insurance if they have a federally backed mortgage.
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