San Mateo County, CA Landscaping Rules: Tree Removal & Heritage Trees (2026)

Under Chapter 8.400 (Ordinance No. 4895, adopted October 22, 2024), Protected Trees include: (1) 'Any tree 12.1 inches in diameter (38 inches circumference) or larger when measured 4.5 feet (54 inches) above natural grade' (Section 8.400.060); (2) listed indigenous species at lower thresholds in Table 1 - most native oaks (coast live oak, black oak, valley oak, etc.), bigleaf maple, alders, and others at 10 inches, Douglas fir and redwood at 18 inches, and Pacific madrone and California buckeye at 6 inches or larger within riparian corridors; (3) Heritage Trees designated by the Board of Supervisors; (4) required replacement or retained trees; (5) communities of five or more indigenous trees; and (6) carbon-sequestration trees. In the Bayside Design Review Districts (Emerald Lake Hills, Oak Knoll Manor, Palomar Park, Devonshire) the protection threshold drops to 6 inches diameter (Section 8.400.070). Removal requires a Protected Tree Removal Permit or an Expedited Tree Removal Permit, with required findings (Section 8.400.150) and replacement planting under Table 2 (Section 8.400.160): one to three replacement trees scaled to the removed canopy, maintained for three years. Resource Management (RM/TPZ) and Coastal Zone districts have separate, sometimes lighter, rules. Fees per County are roughly $670 (removal), $430 (expedited), and processing takes 1-2 months.