119-10 Provisions Regulating Tier I Sites
Tier I sites shall be regulated by the provisions set forth in this Section, inclusive.
To the maximum extent possible, existing trees shall be retained. Trees of six-inch caliper or more may only be removed or destroyed as a result of a development, enlargement or site alteration, provided that:
(a) such trees are located in areas to be occupied by buildings, private roads, driveways, areas for required accessory parking, or within a distance of 15 feet of the exterior walls of such building, provided that it is not possible to avoid such removal by adjustments in the arrangement of such buildings, driveways or required parking areas;
(b) the continued presence of such tree would create special hazards or dangers to persons or property, which would not be possible or practical to eliminate by pruning;
(c) the continued presence of such tree would interfere with the growth or health of another tree of six-inch caliper or more designated for preservation and belonging to a species listed in Appendix B (Selection List for On-site Trees); or
(d) an authorization pursuant to Section 119-313 (Modification of landscaping, tree preservation and tree planting requirements) has been granted by the City Planning Commission approving the removal of such trees.
Any tree of six-inch caliper or more that cannot be preserved as a result of a proposed development, enlargement or site alteration shall be replaced pursuant to the provisions of Section 119-112 (Tier I tree planting requirements).
All developments, enlargements and site alterations on Tier I sites shall comply with the tree planting requirements set forth in this Section, whether or not existing trees are removed as a result of such development, enlargement or site alteration. However, the requirements set forth herein shall not apply to any enlargement of an existing building, provided that such enlargement does not increase the lot coverage of said building.
On-site trees, pre-existing or newly planted, shall be provided on the zoning lot at the rate of one tree for each 1,000 square feet of lot area, or portion thereof, or shall equal a total of 51 percent of all tree credits for trees originally on site, whichever is greater.
For any existing tree of at least six-inch caliper that is preserved, credit for one tree shall be given for the first six inches of caliper and, for each additional four inches of caliper, credit for an additional tree shall be given.
Single-trunk trees, newly planted to meet this requirement, shall be of at least three-inch caliper at the time of planting. Multiple-trunk trees and low-branching coniferous evergreens shall be at least 10 feet in height at the time of planting. On-site trees shall be of a species selected from Appendix B (Selection List for On-site Trees).
The following requirements must be met during construction:
(a) Construction fences shall be erected around all areas of no disturbance.
A tree protection plan is required to modify the area of no disturbance around trees proposed for preservation.
(b) The staging area shall be located in an area that would most minimize destruction of the natural features of the landscape. Such area shall be as close to the construction area on the zoning lot as practical, and shall be either on the flattest portion of the zoning lot or behind a containment wall where it will not erode any area of no disturbance or endanger any tree designated for preservation.
(c) Topsoil shall be used in the area to be revegetated as soon as construction is complete.
(d) Any exposed earth area shall have straw, jute matting or geotextiles placed on it within two days of exposure and be seeded with annual rye grass during construction.
For all developments, enlargements or site alterations on Tier I sites, the following materials shall be submitted to the Department of Buildings. However, the submission requirements set forth herein shall not apply to an enlargement of an existing residential building, provided that such enlargement does not increase the lot coverage of said building. No building permit shall be issued until the Department of Buildings determines that the requirements of the Special Hillsides Preservation District have been met.
(a) A survey map prepared by a licensed surveyor showing topography at two-foot contour intervals and indicating the existing slope of the land, as it occurs, in categories of 10—14 percent, 15—19 percent, 20—24 percent, 25 percent and greater; the location of existing buildings or other structures, patios, decks, swimming pools, walkways, driveways and private roads, including sidewalks and other impervious surfaces; and the location, caliper and species of all trees of six-inch caliper or more on the zoning lot and in the sidewalk area of the adjacent streets.
(b) A site plan prepared by a registered architect or professional engineer indicating the location of all existing buildings or other structures; the location of all proposed buildings or other structures; the location of existing and proposed patios, decks, swimming pools, walkways, driveways and private roads, including sidewalks and other impervious surfaces; the location of any steep slopes, steep slope buffer areas and the staging area; and the location, caliper and species of all trees of six-inch caliper or more on the zoning lot and in the sidewalk area of the adjacent streets. The site plan shall identify those trees proposed to be removed and those trees proposed to be preserved, indicating, for the latter, the critical root zone.
(c) A tree-planting plan, prepared by a registered landscape architect, indicating the location and species of all new plantings, and indicating the location of and the critical root zone around all trees proposed for preservation.
No permanent certificate of occupancy shall be issued by the Department of Buildings unless an inspection report, verifying that the requirements of Section 119-10 (PROVISIONS REGULATING TIER I SITES) have been met, is filed with the Department of Buildings by a registered landscape architect, licensed surveyor, registered architect or professional engineer.