A. General. New development shall retain all existing significant trees, unless the retention of such trees would unreasonably burden the development or cause a significant safety problem, as determined by the City.
B. Site Clearing. No site clearing, grading or removal of significant trees or other vegetation shall take place prior to approval of a proposed landscaping plan. Wholesale clearing or mass grading of sites is discouraged.
C. Retained vegetation shall be oriented, wherever possible, to disconnect adjacent impervious surfaces.
D. Significant Tree Protection Required. Any deciduous and evergreen trees eight inches or greater in diameter, as measured four feet above the ground, is considered a significant tree, with the exception that alders and cottonwoods (Alnas rubra and Populis trichocarpa) are not considered significant. The property owner shall either furnish a site plan showing all free-standing significant trees in areas proposed to be disturbed and the edge of tree cover in areas not proposed to be disturbed, or shall have an arborist provide a certificate stating there are no significant trees on the property.
For property proposed for single-family detached residential development and capable of being subdivided, applicants shall retain significant trees, except in the following areas: utility corridors, roads, and building pads and the yard areas around the proposed residences. For one of these exceptions to apply, the applicant shall depict the area on a site plan showing all free-standing significant trees in areas proposed to be disturbed and the edge of tree cover in areas not proposed to be disturbed. The applicant shall retain significant trees on the subject property to the maximum extent that is practical taking into consideration the nature of the proposed development.
1. Protection Techniques. In order to provide the best possible conditions for the retention of significant trees, the applicant shall comply with the following requirements:
a. The applicant may not fill, excavate, stack, or store any equipment, or disturb or compact the earth in any way within the critical root zone (CRZ) where feasible, which may extend beyond the drip line of existing tree branches of any tree to be retained. A drip line is defined as a perimeter formed by the points farthest away from the trunk of a tree where precipitation from the branches of that tree falls on the ground.
b. The applicant shall construct a temporary but immovable four-foot-high sturdy fence around each tree to be retained, generally corresponding to the drip line of that tree.
c. If the grade level around a tree to be retained is to be raised, the applicant shall construct a dry rock wall or rock well around the tree. The diameter of this wall or well must be equal to the diameter of the tree’s drip line.
d. The applicant may not install impervious surface material within the area defined by the drip line of any tree to be retained, unless specifically approved by the City’s Planning and Development Services Department.
e. The grade level around any tree to be retained may not be lowered within the area defined by the drip line of the tree.
f. The applicant shall prune branches and roots as necessary, and fertilize and water plant material as appropriate.
2. Replacement if significant trees designated to be retained are removed.
a. For trees other than alders and cottonwoods (which are not protected as significant trees), the following shall apply: For any trees to be removed (except for diseased or dying trees) the City shall require the applicant to replant in an appropriate manner. Replacement trees must be at least two and one-half inches in diameter as measured four feet above grade for deciduous trees and a minimum of 10 feet in height for evergreen trees. Trees shall be replaced according to a plan prepared by the applicant and approved by the City. For the removal of diseased or dying trees, an arborist hired by the City at the applicant’s expense shall determine which trees are healthy and shall provide a written report on its findings. Any tree which poses an immediate threat to property may be removed if a report from a qualified consultant is submitted and approved by the City. A two-year maintenance bond shall be provided for all replacement trees in an amount equal to no less than 200 percent of the arborist’s estimate.
b. In the event that a property owner believes that a threat to life or property exists with regard to an existing tree, the property owner may request that the City Planner or designee evaluate the tree, and, if the City Planner concurs that a hazardous condition exists, the property owner may remove the tree without a report from a qualified consultant.
i. Replacement trees may be located in the street planter strip adjacent to the property.
ii. Subdivision development involving the removal of significant trees may locate replacement trees in the street planter strip on or adjacent to the development. If the number of replacement trees exceeds the number of trees required for street planters, then the developer may locate the trees off-site in street planter strips. The location of off-site replacement trees shall be reviewed and approved by the Hearing Examiner.
aFor properties capable of being subdivided, one significant tree for each legal lot area may be removed annually. Property owners shall provide the City with written notice of removal within 30 days of removal.
3. Removal of Trees Designated to Remain. If any tree designated for retention or required to be planted is damaged or destroyed during construction, as a result of on-site construction practices, or within two years following the end of construction, as a result of on-site construction practices, the City shall require the planting of up to three approved trees, each at least two and one-half inches in diameter as measured four feet above grade for deciduous trees and 10 feet in height for evergreen trees, in the immediate vicinity of the damaged or destroyed tree, as determined by the Planning and Development Services Department. The City may require the applicant to remove the damaged or destroyed tree. (Ord. 2315, 2016)