A. Areas of native vegetation which are designated as landscape or buffer areas, or which are otherwise retained under the provisions of Chapter 17.99 GHMC, shall be subject to a 10-foot-wide no-construction zone and shall be protected by a barricade as defined in subsection D of this section. Clearing, grading or contour alteration is not permitted within this no-construction area unless a qualified arborist provides written documentation that proposed construction activity within the 10-foot setback will not harm existing vegetation within the designated landscape or buffer area.

B. Encroachment into Drip Line. No construction activities shall take place within the drip line of a tree to be retained without extra precautions as recommended by a qualified arborist. The applicant may install impermeable or compactible surface within the area defined by the drip line if it is demonstrated by a qualified arborist that such activities will not endanger the tree or trees. (See the definition of “drip line” in GHMC 17.99.590.)

C. Grading. If the grade level adjoining a tree to be retained is to be altered to a degree that would endanger the viability of a tree or trees, then the applicant shall construct a dry rock wall or rock well around the tree. The diameter of this wall or well must be capable of protecting the tree beyond a no-construction zone or as approved by a qualified arborist.

D. Tree Protection Barricade. All significant trees to be retained must be protected during construction by installation of a protective barricade. This will require preliminary identification of the proposed area of disturbance for staff inspection and approval, then installation of a protective barricade before major excavation with heavy equipment begins. The barricade must be made of cylindrical steel posts or four-inch by four-inch wood posts with chain link fence attached. Fence posts shall be eight feet on center connected with two-inch by four-inch top rails or equivalent support system. Fence height must be a minimum of four feet high. (Ord. 1347 § 53, 2016).