Topanga, CA Tree Protection: Tree Ordinances (2026)

Los Angeles County's Oak Tree Ordinance (Chapter 22.174 of the County Code) provides comprehensive protection for oak trees in unincorporated areas. The ordinance applies to native oak trees with trunks measuring 8 inches or more in diameter at breast height (4.5 feet above ground). A permit from the Department of Regional Planning is required before any oak tree can be removed, relocated, or significantly encroached upon. The permit process requires submission of an oak tree report prepared by a certified arborist. Heritage oaks and specimens of exceptional size or historical value receive the highest level of protection, and removal is generally discouraged. When removal is approved, mitigation is required including replacement planting at a ratio determined by the reviewing authority, typically 2:1 or higher. In-lieu fees may be accepted when on-site replacement is not feasible. The county also protects trees through its Significant Ecological Areas (SEA) program, which adds additional environmental review for development in sensitive habitats. Street trees in county-maintained rights-of-way are managed by the Department of Public Works.