San Mateo County requires 100 feet of defensible space around all structures in State Responsibility Areas (SRA) and designated Very High Fire Hazard Severity Zones (VHFHSZ) per California Public Resources Code §4291. The County Fire Marshal (Cal Fire San Mateo-Santa Cruz Unit) conducts annual LE-100 inspections in coastal mountain communities including La Honda, Pescadero, Loma Mar, Woodside hills, and Emerald Hills. Failure to clear triggers abatement at the owner's expense plus administrative liens.
Defensible space is mandated by PRC §4291 and Government Code §51182, enforced in unincorporated San Mateo County by the County Fire Department (operated under contract by Cal Fire's San Mateo-Santa Cruz Unit). Zone 0 (0-5 ft ember-resistant zone) is being phased in under AB 3074, requiring non-combustible materials immediately adjacent to structures. Zone 1 (0-30 ft) requires removing dead vegetation, trimming trees 10 ft from chimneys, clearing roofs/gutters of leaves, and maintaining 10 ft spacing between tree crowns. Zone 2 (30-100 ft) requires reducing surface fuel, creating horizontal/vertical spacing between shrubs and trees, and removing ladder fuels. Annual inspections occur May-October; LE-100 notices are mailed first. The County also enforces WUI building code Chapter 7A for construction in VHFHSZ — ignition-resistant exterior materials, ember-resistant vents, and Class A roofing required. The San Mateo RCD Neighborhood Chipper Program provides free chipping in eligible neighborhoods.
PRC §4291 non-compliance: up to $500 per day, reinspection fees $150+. County abatement contractor clears property and liens owner for actual costs ($500-$5,000+). Second failed inspection: escalated administrative penalties. Fire caused by failure to clear: civil liability for suppression costs.
San Mateo County, CA
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San Mateo County, CA
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San Mateo County, CA
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San Mateo County, CA
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See how San Mateo County's brush clearance rules stack up against other locations.
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