Santa Clara County— fire, flood & earthquake hazard information
Santa Clara County is a county in the San Francisco Bay Area, covering about 1291.1 square miles. This page summarizes what official government maps show for Santa Clara County: 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 Santa Clara County’s area that falls inside each mapped zone.
View Santa Clara County on the interactive map → to check any specific address, free.
Wildfire hazard severity zones
Per CAL FIRE's Fire Hazard Severity Zone maps, 19% of Santa Clara County is in a Very High fire hazard severity zone, 44% is in a High zone, 2% is in a Moderate zone. The remainder of its area is outside currently designated zones.
| Very High severity zone | 19% |
| High severity zone | 44% |
| Moderate severity zone | 2% |
FEMA flood zones
7% of Santa Clara County lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); less than 1% is in a coastal high hazard zone (V/VE); 9% 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) | 7% |
| Coastal high hazard (V/VE) | less than 1% |
| 0.2% annual chance (500-yr) | 9% |
Earthquake faults & seismic zones
The nearest mapped fault, the Coyote Creek fault zone, is about 1.2 mi (2.0 km) from the center of Santa Clara County. 22 named fault traces in the USGS Quaternary fault database cross its boundary. 13% of its area is in a state-designated liquefaction zone of required investigation. 16% is in an earthquake-induced landslide zone. 3% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
| Nearest mapped fault | Coyote Creek fault zone — 1.2 mi (2.0 km) |
| Named fault traces crossing boundary | 22 |
| Liquefaction zone | 13% |
| Earthquake-induced landslide zone | 16% |
| Alquist-Priolo fault zone | 3% |
Dam inundation, aircraft noise & air quality
12% of Santa Clara County lies within a state-reviewed dam-failure inundation area; less than 1% is inside an airport noise contour of 65 dB CNEL or louder; annual average fine-particle (PM2.5) concentration across its census tracts is 7.0 μg/m³, and its composite pollution burden ranks around the 41th percentile statewide.
| Dam-failure inundation area | 12% |
| Airport noise ≥65 dB CNEL | less than 1% |
| Annual PM2.5 (tract average) | 7.0 μg/m³ |
| Pollution burden percentile (statewide) | ~41 |
Frequently asked questions
- Is Santa Clara County in a wildfire hazard severity zone?
- Per CAL FIRE's Fire Hazard Severity Zone maps, 19% of Santa Clara County is in a Very High fire hazard severity zone, 44% is in a High zone, 2% is in a Moderate zone. The remainder of its area is outside currently designated zones.
- Is Santa Clara County in a FEMA flood zone?
- 7% of Santa Clara County lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); less than 1% is in a coastal high hazard zone (V/VE); 9% 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 Santa Clara County?
- The nearest mapped fault, the Coyote Creek fault zone, is about 1.2 mi (2.0 km) from the center of Santa Clara County. 22 named fault traces in the USGS Quaternary fault database cross its boundary. 13% of its area is in a state-designated liquefaction zone of required investigation. 16% is in an earthquake-induced landslide zone. 3% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
- How do I check a specific address in Santa Clara County?
- Use the free sitelume interactive map at https://sitelume.com — search any Santa Clara County address to see which mapped zones it falls in, layer by layer.
Cities in Santa Clara 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.