Aliso Viejo, CA Environmental Rules: Defensible Space (2026)

AVMC 15.50.010 is the Aliso Viejo zoning code's fire hazard section, and its stated purpose is to implement the general plan safety element. It applies in two situations: all areas the general plan safety policy map places in a very high fire hazard severity zone, and any project where a fuel modification plan has been required as a condition of development approval or by regulations administered by a public agency. Development under the section must be provided with effective fire protection through fuel modification programs, access roads, sufficient water supply, landscaping and open spaces, as the fire chief determines.

The process runs through a plan. A preliminary fuel modification plan must be approved by both the fire chief and the planning director before the first discretionary action on the project. The design and width of each zone are set on the plan according to individual site conditions, and zones on an approved plan have the same force and effect as the text of the zoning code. Every plan must carry a maintenance program for continuous upkeep, covering irrigation systems and landscaping, periodic re-thinning of vegetation and other measures needed to keep the zones in a fire safe condition. The property owner pays for design, implementation and maintenance.

Other chapters stack on top. Under AVMC 14.10.160, a subdivision in a high or extreme fire hazard area must provide firebreaks and fuel modification programs, the subdivider pays for design and implementation, and the fire chief and the director approve the method of continued maintenance. AVMC 13.02.130 requires the Orange County Fire Authority to review and approve fuel modification plans for all new buildings in a wildfire risk area against OCFA Guideline C-05, and Section 324.1 in AVMC 13.04.030 applies the same guideline to new structures adjoining land with hazardous combustible vegetation. Section 326.1 lets the Fire Code Official suspend vegetation management requirements and require alternatives for difficult terrain, danger of erosion, listed rare or threatened plants, stands or groves of trees or heritage trees. Burning wood or solid fuel inside a fuel modification zone is barred by Section 307.6.2.1 of the same chapter.