Purpose: These regulations recognize the need to alter the landscape during site development activities, while setting out standards necessary to ensure tree preservation and protection of environmentally sensitive areas to the greatest extent possible. This section balances the City’s tree preservation goals with market and permit streamlining objectives by giving applicants the option to survey individual trees to protect tree stands, and to provide off-site mitigation in lieu of preserving trees on site.
B. Minimum Requirements
1. Protected Tree Designations
This subsection designates the types of trees that are subject to protection under this section, and establishes a threshold trunk size, measured in diameter at breast height (DBH), for various tree species.
a. A significant tree means a tree of eight (8) inches or greater, as measured four and one-half (4½) feet above the ground, for all tree species except for non-native invasive species.
b. The applicant may omit trees that are not considered significant from the tree survey.
2. Tree Designation Alternative
a. The table below establishes the minimum percentage of all diameter inches or percent tree canopy of significant trees that must be preserved or mitigated. For single-family dwellings, developers and builders may elect to preserve trees at the platting or building permit stage. If a developer or builder elects to preserve at the platting stage, this method must be used throughout completion of the project.
Up to 90% of significant trees may be mitigated rather than preserved.
Up to 90% of significant trees may be mitigated rather than preserved.
b. Calculation of Preservation Ratios
All percentages relating to preservation stated within this section are based on the tree survey. Any subsequent redevelopment of property must minimally preserve the applicable percentage of the total diameter inches of protected trees as indicated by the tree survey.
3. Tree Stand Delineation Alternative
As an alternative to a tree survey, a tree stand delineation may be used to meet the preservation requirements (see submittal requirements Chapter 18.94). In order to use this provision, the site must have area(s) of tree canopy that meet the woodlands criteria as set forth below and must contain existing native understory vegetation.
A “woodland” is an area of contiguous wooded vegetation where trees are at a density of at least one (1) significant tree per 500 square feet of land and where the branches and leaves form a continuous canopy. A woodland must include areas with a continuous canopy of trees over an area of at least twenty thousand (20,000) square feet and with any dimension being at least 35 feet. A woodland may be delineated through an aerial photograph or a ground survey. A woodland must include both understory and protected trees.
A tree stand delineation must meet the following standards:
(1) A tree preservation plan submitted at the master development plan stage must preserve a minimum of 20 percent of contiguous tree canopy with the understory.
(3) Tree canopy area(s) to be preserved as tree save area(s) must include environmentally sensitive areas that are present on site; including steep slopes, drainage areas, riparian buffers, or corridors along arterial and collector streets.
C. Tree Survey and Photogrammetric Documentation
1. An applicant who selects the Tree Designation Alternative must submit a tree survey and photogrammetric documentation indicating the size and common name of trees within the application area. The survey must identify by common name and indicate by caliper size each Significant Tree.
2. The tree survey must be prepared on a topographic survey of the site to establish the tree elevation at the trunk and the drip line for individual trees and at the edge of the drip line for wooded areas.
D. Permitting Requirements
1. The developer must prepare and present a tree preservation conservation plan and statement of intent at the time of a pre-application meeting or submittal of this information with application for a plat, rezoning or final site development plan.
2. The conservation plan must:
a. identify the general location and massing of wooded areas, areas with dense shrubbery, and isolated individual mature hardwood trees,
b. designate which areas or trees are to be preserved and which are to be removed;
d. indicate which trees and wooded areas are to be protected and the measures proposed to protect them during the construction phase.
E. Protection of Existing Trees
1. Existing trees and their root zones that are to be saved must be protected from all construction activities, including earthwork operations, movement and storage of equipment and vehicles and placement of construction materials and debris. No structure will encroach within/over a tree preservation easement.
2. Erosion protection measures may be required to prevent siltation of the tree preservation areas during construction.
3. Every effort must be made to locate utility easements away from tree preservation areas. However, utility easements may be located adjacent to tree preservation areas as long as adequate clearance and protection is provided for the tree preservation area during the installation of the utilities adjacent to the tree preservation easement. When utilities or infrastructure systems must cross tree preservation areas, every effort must be made to minimize tree removal in such areas. If the removal of trees within these areas is determined to be excessive, the Planning Official may require the developer to replace the trees or pay into a Tree Preservation Escrow.
4. To ensure protection of tree preservation areas, protection zones must be delineated on plats, rezoning and final site development plans. During the construction process, the protection zones must be identified on the property using standard orange barricade fencing or comparable fencing material. The fencing must be four (4) feet in height and supported by metal channel posts spaced at a minimum of ten (10) feet on center. The fencing must be placed around all trees or wooded areas to be protected and remain erect and secure throughout all construction phases.
5. A tree preservation plan and statement of intent is required prior to removal of twenty (20) percent of existing woodland area or more when not associated with a pending development case. This requirement pertains to all properties zoned residential or used as a residence in excess of ten (10) acres and all other properties in excess of five (5) acres in size.
A credit may be granted for all existing hardwood and evergreen trees indicated to be preserved. Trees that measure from two and one-half (2½) to eight (8) inches in caliper, as measured four and one-half (4½) feet above ground level, may be credited on a one (1) tree for one (1) tree basis. Trees that measure greater than eight (8) inches in caliper may be credited on a two (2) tree for one (1) tree basis. Credited trees may only be located in that portion of the development project where new tree plantings are otherwise required, or in a Type “N” buffer as designated in Section 18.30.130. Tree credits will not be granted if one (1) of the following conditions exists:
1. Trees posing imminent danger to the public health, welfare or safety of the residents of the City of Olathe. In those instances, the Planning Official may give verbal authorization to remove the trees.
2. Trees that are diseased, injured, in danger of falling, or too close to existing or proposed structures.
3. Trees interfering with existing utility service, or creating unsafe vision clearance.
1. Any tree or trees removed from within an approved tree preservation area must be replaced with similar species or other hardwood species.
2. Replacement trees must meet the minimum requirements for trees as defined in subsection B above at the rate of one (1) inch caliper of replacement tree for every one (1) inch caliper of tree removed.
3. In lieu of protecting trees on-site, the applicant may provide a cash escrow equivalent to one and one-half (1½) times the monetary value of the tree or topsoil removed or destroyed up to a maximum of ten thousand dollars ($10,000) per occurrence. Monetary value is to be determined by referring to current tables and formulas produced by the Council of Tree and Landscape Appraisers. The developer or owner will incur the cost for the appraisal to be completed by a certified arborist using the International Society of Arboriculture Manual of Plant Appraisal. The Tree Preservation Escrow Account must be used to install new trees on City-owned and publicly accessible property or rights-of-way.
H. Removal of Trees Within Existing Tree Preservation Areas:
Property owners may not remove trees meeting the minimum requirements for tree preservation unless mitigation is provided (see subsection G, above).