Walnut Creek, CA— fire, flood & earthquake hazard information
Walnut Creek is a city in Contra Costa County in the San Francisco Bay Area, covering about 19.8 square miles. This page summarizes what official government maps show for Walnut Creek: CAL FIRE fire hazard severity zones, FEMA flood zones, state seismic hazard zones, dam inundation areas, airport noise contours, and air-quality indicators. Figures are the share of Walnut Creek’s area that falls inside each mapped zone.
View Walnut Creek on the interactive map → to check any specific address, free.
Wildfire hazard severity zones
CAL FIRE's current Fire Hazard Severity Zone maps do not designate any zones within Walnut Creek. Individual properties near the boundary can still fall inside a neighboring zone — check the exact address on the map.
FEMA flood zones
1% of Walnut Creek lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 1% is in the 0.2% annual chance (500-year) area. Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
| Special Flood Hazard Area (100-yr) | 1% |
| 0.2% annual chance (500-yr) | 1% |
Earthquake faults & seismic zones
The nearest mapped fault, the Concord fault, is about 1.4 mi (2.3 km) from the center of Walnut Creek. 3 named fault traces in the USGS Quaternary fault database cross its boundary. 44% of its area is in a state-designated liquefaction zone of required investigation. 18% is in an earthquake-induced landslide zone. 2% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
| Nearest mapped fault | Concord fault — 1.4 mi (2.3 km) |
| Named fault traces crossing boundary | 3 |
| Liquefaction zone | 44% |
| Earthquake-induced landslide zone | 18% |
| Alquist-Priolo fault zone | 2% |
Dam inundation, aircraft noise & air quality
6% of Walnut Creek lies within a state-reviewed dam-failure inundation area; annual average fine-particle (PM2.5) concentration across its census tracts is 8.8 μg/m³, and its composite pollution burden ranks around the 16th percentile statewide.
| Dam-failure inundation area | 6% |
| Annual PM2.5 (tract average) | 8.8 μg/m³ |
| Pollution burden percentile (statewide) | ~16 |
Frequently asked questions
- Is Walnut Creek in a wildfire hazard severity zone?
- CAL FIRE's current Fire Hazard Severity Zone maps do not designate any zones within Walnut Creek. Individual properties near the boundary can still fall inside a neighboring zone — check the exact address on the map.
- Is Walnut Creek in a FEMA flood zone?
- 1% of Walnut Creek lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 1% is in the 0.2% annual chance (500-year) area. Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
- What earthquake faults and seismic zones affect Walnut Creek?
- The nearest mapped fault, the Concord fault, is about 1.4 mi (2.3 km) from the center of Walnut Creek. 3 named fault traces in the USGS Quaternary fault database cross its boundary. 44% of its area is in a state-designated liquefaction zone of required investigation. 18% is in an earthquake-induced landslide zone. 2% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
- How do I check a specific address in Walnut Creek?
- Use the free sitelume interactive map at https://sitelume.com — search any Walnut Creek address to see which mapped zones it falls in, layer by layer.
Nearby in Contra Costa County
Sources: CAL FIRE Fire Hazard Severity Zones; FEMA National Flood Hazard Layer; USGS Quaternary Faults; CGS Seismic Hazard Zones & Alquist-Priolo zones; Cal OES dam inundation maps; county ALUC noise contours; CalEnviroScreen 4.0. Area shares are computed against each place’s Census TIGER boundary (last computed 2026-07-24). Boundaries and zone designations change; always verify with the issuing agency.