Colusa County, CA Fire Regulations: Wildfire Zones (2026)

Colusa County is geographically split: the eastern half is flat Sacramento Valley rice and row-crop land (Colusa, Williams, Arbuckle, Maxwell), while the western half rises into the Coast Range foothills toward Stonyford, Lodoga and the Mendocino National Forest, where wildfire risk is concentrated. Most of the unincorporated county lies in State Responsibility Area (SRA), where CAL FIRE's Sonoma-Lake-Napa Unit (LNU) holds primary wildfire-protection responsibility. CAL FIRE designates Fire Hazard Severity Zones (Moderate, High, Very High); the western foothills carry the higher classifications. In SRA, California Public Resources Code 4291 requires property owners to maintain defensible space — clearance of 100 feet 'from each side and from the front and rear of the structure, but not beyond the property line.' Fuel management is most intense within 30 feet and an ember-resistant zone is required within 5 feet of the structure. The county supplements this with its own weed-abatement ordinance (Code Chapter 7A) requiring 50-foot clearance around structures, and Code Chapter 7 firebreak provisions (Sec. 7-10 through 7-16) requiring firebreaks around grain fields, warehouses (20 feet) and other buildings (20 feet). CAL FIRE conducts defensible-space inspections in SRA and can require compliance. New construction in higher hazard zones must also meet the state's Wildland-Urban Interface building standards (California Building Code Chapter 7A).