The director shall determine during the project review process whether and to what extent conditions or measures will be required to protect parkway trees during construction. This decision shall be based upon the proximity of the construction activity to parkway trees. The conditions and protective measures include, but are not limited to, the following:
(1) The parkway trees shall be enclosed by chain link fencing with a minimum height of five feet or by another protective barrier approved by the director prior to the issuance of a grading or building permit and prior to commencement of work.
(2) Barriers shall be placed at least five feet outside the drip line of parkway trees. A lesser distance may be approved by the director if appropriate to the species and the adjacent construction activity.
(3) No grade changes shall be made within the protective barriers without prior approval by the director. Any roots greater than two inches in diameter which are damaged or exposed shall be cleanly saw cut and covered with soil in conformance with industry standards.
(4) Excavation or landscape preparation within the protective barriers shall be limited to the use of hand tools and small hand-held power tools and shall not be used at a depth that could cause root damage to the parkway tree.
(5) No attachments or wires other than those of a protective or non-damaging nature shall be attached to a parkway tree.
(6) No equipment or debris of any kind shall be placed within the protective barriers. No fuel, paint, solvent, oil, thinner, asphalt, cement, grout or any other construction chemical shall be stored or allowed in any manner to enter within the protective barrier.
(7) If access within the protective barrier around a parkway tree is required during the construction process, the route shall be covered in a six-inch mulch bed in the drip line area, and the area shall be aerated and fertilized at the conclusion of the construction.
(8) When the existing grade around a parkway tree is to be raised, drain tiles shall be laid over the soil to drain liquids away from the trunk, as determined by the director. The number of drains shall depend upon the soil material. Lighter sandy soils and porous gravelly material require fewer drains than heavy non-porous soils like clay. Dry wells shall be large enough to allow for maximum growth of the tree trunk. Dry well walls shall be constructed of materials that permit passage of air and water.
(9) When the existing grade around a parkway tree is to be lowered, either by terracing or a retaining wall, a combination may be used to lower grade, as determined by the director. With either method, the area within the drip line shall be left at the original grade. The retaining wall shall be porous to allow for aeration.
(10) Parkway trees that have been destroyed or that have received major damage during construction shall be replaced prior to final inspection and subject to the director's approval as to size, variety and species.
(Ord. 556 § 2 (part), 2000).