§ 18.12.508. Permitted Construction Methods.

(a)

Boring. Boring of utilities under protected trees may be required in certain circumstances. When required, the length of the bore shall be at a minimum the width of the critical root zone, and shall be at a minimum depth of 48 inches.

(b)

Grade Change. Grade changes within the critical root zone of a protected tree should not exceed two inches. If more than 25 percent of the critical root zone is disturbed by trenching or a grade change greater than two inches, the applicant may be required to prune the root zone or tree canopy in accordance with industry standards, or to take some other mitigative measure to help preserve the health of the tree.

(c)

Trenching. All trenching shall be designed to avoid crossing the critical root zone of any protected tree.

(d)

Root Pruning. All roots two inches or larger in diameter which are exposed as a result of trenching or other excavation, shall be cut off and covered with pruning compound within two hours of initial exposure.

(Ord. No. 5189, § 1, 9-26-00)