The purpose and intent of this section establishes regulations for the preservation of natural areas to prevent the unnecessary cutting, removal, or killing of trees, and/or native vegetation; to provide protection for these critical areas including woodlands or high tree concentrations; critical habitats that contain rare, threatened or endangered species; wooded 100-year floodplains; wooded wetlands; wooded slopes; wooded or partially wooded stream corridors with drainage areas greater than 50 acres; and riparian areas. The intent is to promote the health, attractiveness, and safety of the community; to foster aesthetically pleasing and environmentally sensitive development that protects and preserves the appearance and character of the city, and encourages preservation of natural areas such as mature tree stands and stream corridors. These regulations promote important physical and psychological benefits through the use of preservation and protection of the natural areas reducing noise and light pollution; promoting innovative and cost conscious approaches to design, installation, and maintenance of said areas, and establishes procedures for the administration and enforcement. These regulations apply to both new site development and any redevelopment of a site.
(A) Natural Area Tree Preservation Plans.
(1) Tree preservation plans shall be submitted prior to any site development including redevelopment of a site, grading, excavating, construction of a new building or structure, new site development and/or any other use or permit as deemed appropriate by the Director of Planning or his or her designee.
(2) Evaluation of the tract’s natural areas shall be undertaken by an arborist, landscape architect, or horticulturalist.
(3) All trees which possess a diameter requirement of a minimum of six inches shall be inventoried and included on the tree preservation plan.
(4) Tree preservation plans shall detail locations, sizes, and common name of preserved trees, individual shrubs, areas of dense tree or shrub concentrations, and other natural features that are to be preserved or removed.
(5) Existing trees that are preserved shall be credited toward required landscaping requirements based on the sizes and locations of such preserved trees.
(6) Fencing, barriers, or other materials shall be specified on the tree preservation plan. All tree preservation plans shall be approved by the Director of Planning and Development or his/her designee.
(B) Tree Preservation.
(1) Trees must have a life expectancy of greater than ten years.
(2) Trees/vegetation shall be in good condition.
(3) Trees shall have a relative sound and solid trunk with no extensive decay.
(4) Trees shall have no more than one major dead limb or several minor dead limbs.
(5) Trees shall have no major insect or pathological problems.
(C) Tree Preservation Efforts.
(1) The practicality of arranging the site plan components around existing natural areas shall adhere to the following:
(a) Plans for groups of structures should be designed to preserve areas of high tree concentrations, desirable individual tree specimens, and desirable stands of trees and shrubs.
(b) The condition of the vegetation with respect to its continued vitality.
(c) The possibility of preserving vegetation through pruning rather than removal.
(d) The desirability of a particular tree or species by reason of its appearance, historic or ecological significance, botanical characteristics, and the function that the vegetation would fulfill as a site plan component.
(e) The practicality and economic possibility of designing the location and grades of proposed structures and paving to preserve existing vegetation.
(f) The potential for interference with utility services along the use of the roads and walkways.
(D) Credits for Saving Mature Trees. Where it is possible to save older and/or larger trees, each tree determined to qualify and designated on the landscape plan subsequently shall be saved and credited toward other required tree plantings. The location of the trees to be saved shall be used to determine the areas where landscaping requirements can be redirected. The diameter of the trees that qualify under this section, and the respective credits that they merit, are listed in the table below:
Table 12.0.12.D. TREE PRESERVATION CREDITS | |
Diameter of Tree (measured at a point four feet above grade) | Credit |
Less than 2.5 inches | No Credit |
2.6 inches to 5.9 inches | 1 to 1 |
6 to 17.9 inches | 2 to 1 |
18 inches or greater | 3 to 1 |
(E) Protection Practices.
(1) Protecting the root zone is the most critical factor in tree preservation throughout the development process. Disturbances within this area directly affect tree survival. To protect the root zones, the following standards apply:
(a) When earthwork, grading, or construction activities are planned adjacent to a natural area, a limit of disturbance line shall be shown on the construction plans and tree preservation plans. All such areas shall be protected through installation of temporary fencing, barriers, or other measures approved by the Director of Planning. Such fencing, barriers, or other materials shall be installed and identified through signage as a “TREE PRESERVATION ZONE” (multiple signs) prior to commencing land disturbance, and shall remain throughout the period of construction.
(b) Barriers shall be used to protect trees during site development. The root zone of trees shall include no less than the total area beneath the tree(s) canopy as defined by the farthest canopy of the tree(s) plus a five-foot wide protective buffer.
(c) Disturbed areas adjacent to tree preservation zones shall be mulched to provide additional protection to tree roots.
(d) Grading measures or protective devices, such as tree wells, tree walls, or specialized fill and pavement designs, shall be installed when necessary to preserve identified tree specimens.
(e) Grade changes adjacent to tree preservation zones shall not result in alteration to soil or drainage conditions that would adversely affect existing vegetation. These areas shall be evaluated for flood tolerance and stormwater routed around these areas deemed intolerant of an increase of additional flow from urbanization.
(f) Construction site activities such as parking, material storage, burry pits, concrete washout, etc., shall not be allowed within the tree preservation zone.
(g) The determination of sight-distance clearances along roadways shall be completed graphically and submitted to the Department of Planning and Development for review and approval.
(h) No disturbance shall be permitted within the tree preservation zone including trenching, backfilling, driving or parking equipment, and/or dumping of trash, oil, paint, or other materials detrimental to plant health. No vehicles, machinery, tools, chemicals, construction materials, or temporary soil deposits shall be permitted within such barriers. No notices or other objects shall be nailed or stapled to preserved trees.
(i) Mature trees shall not be topped. The trees shall be pruned according to procedures established by the American National Standards Institute A300 Pruning Standards.
(j) Should any tree designated for preservation die within five years of project completion, the owner/developer/ association shall replace such tree with a tree of equal tree preservation value within 180 days based on the following calculations:
Table 12.0.12.E.j. TREE PRESERVATION REPLACEMENT REQUIREMENT | |
Diameter of Tree Removed | Calculation for required number of replacement trees at 2.5 inches caliper |
Less than 8 inches | Diameter of tree removed divided by 2.5 |
8 to 16 inches | 2 times diameter of tree removed divided by 2.5 |
Greater than 16 inches | 4 times diameter of tree removed divided by 2.5 |
(k) Trees, vegetation, and shrub removal shall not be permitted prior to the issuance of an improvement location permit.
(l) Plantings, landscaping, and removal of existing natural areas shall be subject to inspections to verify compliance.
(Ord. 64-11-08, passed 12-9-08; Am. Ord. 32-10-11, passed 11-15-11; Am. Ord. 10-03-13, passed 4-9-13)