Highland, CA Environmental Rules: Defensible Space (2026)

Highland's defensible space rules sit in the fire safety regulations of the development code, HMC § 16.40.450, and they attach to development projects. Subsection A applies the section to all phases of a project. Every land use application that would lead to construction or expansion of a structure or the subdivision of land goes from the planning division to the responsible fire authority and the appropriate resource conservation district office for review, and recommendations are folded into conditions of approval where possible. If the adopted building, residential, or fire codes conflict with the section, those codes take precedence.

The core rule is subsection D. A permanent fuel modification area is required around development projects or portions of them that are adjacent or exposed to hazardous fire areas. The responsible fire authority sets the width with the fire department, and the width can never be under 100 feet as measured from the development perimeter. The listed factors are natural ungraded slope, fuel loading, access to the project and to the fuel modified area, on-site water available for firefighting, continual maintenance (with common open space preferred where feasible), and soil erosion and sediment control. Phased projects can be required to provide temporary fuel modification areas.

Other numbers apply. Under subsection B, buildings on lots created after the section took effect must sit at least 30 feet from the boundary of the San Bernardino National Forest and State Regulated Areas. On slopes greater than 30 percent and at least 30 feet in height, the vegetation is treated as a fuel modified area maintained for the entire slope, 100 feet, or the property line, whichever distance is less. Private residential driveways cannot exceed 150 feet unless the fire code official approves. In a very-high fire hazard severity zone, subsection C requires fences within fuel modification zones or wildland-urban interface areas to be noncombustible and requires at least two three-quarter-inch hose faucets per structure.

HMC § 15.16.030 backs this up. It adds Section 602.3.3 to the California Wildland-Urban Interface Code with the same 100-foot floor, and Section 604.6 lets the fire code official suspend enforcement and require reasonable alternatives for difficult terrain, danger of erosion, protected plants, or stands or groves of trees.