Walnut Creek, CA Landscaping Rules: Tree Trimming (2026)

816-6.6002 — Prohibition. No person shall trench, grade or fill within the dripline of any protected tree or cut down, destroy, trim by topping or remove any protected tree on private property within the county without a tree permit, except as provided for in Section 816-4.1002. 816-6.6004 — Protected trees. A protected tree is any one of the following: (1) On all properties within the unincorporated area of the county: (A) Where the tree to be cut down, destroyed or trimmed by topping is adjacent to or part of a riparian, foothill woodland or oak savanna area, or part of a stand of four or more trees, measures twenty inches or larger in circumference (approximately 6.5 inches in diameter) as measured four and one-half feet from ground level, and is included in the [list of indigenous trees: Bigleaf Maple, Box Elder, California Buckeye, White Alder, Madrone, Toyon, California Black Walnut, California Juniper, Tanoak, Knobcone Pine, Digger Pine, California Sycamore, Fremont Cottonwood, Black Cottonwood, Coast Live Oak, Canyon Live Oak, Blue Oak, California Black Oak, Valley Oak, Interior Live Oak, Yellow Willow, Red Willow, Arroyo Willow, Coast Red Elderberry, Coast Redwood, California Bay or Laurel]; (B) Any tree shown to be preserved on an approved tentative map, development or site plan or required to be retained as a condition of approval; (C) Any tree required to be planted as a replacement for an unlawfully removed tree. (2) On any of the properties specified in subsection (3) of this section: (A) Any tree measuring twenty inches or larger in circumference (approximately six and one-half inches diameter), measured four and one-half feet from ground level including the oak trees listed above; (B) Any multistemmed tree with the sum of the circumferences measuring forty inches or larger, measured four and one-half feet from ground level; (C) And any significant grouping of trees, including groves of four or more trees. (Ords. 94-59, 94-22.) 816-6.8002 — Permit requirement. Any person proposing to trench, grade or fill within the dripline of any protected tree or cut down, destroy, trim by topping or remove any protected tree shall apply to the department for a tree permit, not less than ten days prior to the proposed tree removal or tree alterations. 816-6.4018 — Topping. 'Topping' is the removal of the upper twenty-five percent or more of a tree's trunk(s) or primary leader. 816-6.4016 — Routine pruning. 'Routine pruning' means the removal of dead or dying, diseased, weak or objectionable branches of a tree in a reasonable and scientific manner which does not structurally harm the tree. 816-6.1002(3) — Routine pruning not involving topping or tree removal [does not require a tree permit].