The owner/developer shall comply with the following provisions:
(a) Pre-Construction Record. A video tape record shall be filed with the Building Commissioner prior to any building, grading or clearing activity on the parcel to be developed. This video tape record shall completely depict the pre-development condition of the parcel in sufficient detail to enable the Building Commissioner to evaluate compliance with these regulations during and following completion of construction activities under these regulations. The Building Commissioner shall have the authority to request additional video tape records of pre-development conditions of the parcel being developed to satisfy the intent of this section when in his opinion such additional records are required.
(b) Grading Plans. A grading plan shall be required for each lot in conformance with Section 1115.03
of the Subdivision Regulations and in addition shall show the natural topography of the total parcel to be developed, the location and size of all structures, the finish grade of all improvement locations and the dimensions, elevations and contours of any proposed earth moving and shall be submitted with each application for a hillside protection permit and shall show the following:
(1) A detailed topographic map. A contour map with two-foot integrals or suitable cross sections or profiles of areas where streets, driveways, buildings, utilities or grading construction is proposed shall be required.
(2) Road profiles. Profiles and cross sections of all significant changes in the cross slopes; the cross section to show proposed and natural grade at the centerline of the road, the right-of-way line and the proposed building setback lines shall be required.
(3) Special terrain notes. Notes and details of existing terrain shall be shown over the required topographic information.
(4) Material disposal. A description shall be included of methods to be employed in disposing of soil and other material removed, including the location of the disposal site.
(5) Timetable. A schedule shall be included showing when each stage of the project will be completed, including the estimated starting and completion dates.
(c) Earth Moving Controls. The following minimum standards shall apply to earth moving:
(1) Minimum alterations. Earth moving shall be limited to the minimum required for building foundations, driveways, drainage control structures and immediate yard areas. With the exception of purely stockpiling or restoration efforts, substantial earth moving shall not be permitted.
(2) Erosion control. All earth moving shall create the lowest possible potential for airborne or waterborne transportation of soil.
(3) Compaction. All fill shall be stabilized in conformance with generally accepted engineering standards, including a compacted density of a least ninety-five percent (95%).
(4) Prompt completion. All earth moving shall be accomplished in the shortest practical period of time. In no event shall the existing natural vegetation be destroyed, removed or disturbed more than fifteen days prior to the initiation of construction.
(5) Cut and fill. Cut and fill slopes shall be no steeper than two horizontal to one vertical; fill slopes shall not be located on natural slopes steeper than 2:1; or where fill slope toes out within twelve feet horizontal of the top of an existing or planned cut slope.
(6) No unnecessary cuts and/or fills shall be allowed in order to create additional lots or building sites.
(d) Hydrological Controls. The following standards shall apply to hydrological controls:
(1) Natural channels. Natural drainageways shall be preserved to the maximum extent possible.
(2) Controlled run-off. Run-off from concentrated impervious surfaces shall be collected and transported in a pipe or other approved manner to a City storm sewer system if available, or if unavailable, to the bottom of a ravine in a safe, adequate and nonerosive manner. Where required by the City Engineer, or the CSWD, storm water retention facilities shall be installed.
(3) Interceptor ditches. Where required, interceptor ditches shall be established above steep slopes in such a way as not to saturate or erode soil, and the intercepted water shall be conveyed in a pipe or other approved manner to a City storm sewer system or to the bottom of a ravine or steep slope.
(4) Discharge point stabilization. Natural drainageways shall be established by means consistent with sound professional engineering practice, below drainage and culvert discharge points for a distance sufficient to convey the discharge without channel erosion and in such manner as to dissipate the energy of the discharge.
(5) Early completion. The overall drainage system shall be completed and made operational at the earliest possible time during construction.
(6) Impact on adjacent property. Natural or usual flow of surface or subsurface water shall not be altered or obstructed in any way by grade changes that may adversely affect the property of another by either contributing to pooling or collection of waters, or to the concentration or intensification of surface water discharge. However, construction which might otherwise be prohibited hereinabove may be allowed if such waters are safely and adequately drained in a nonerosive manner by a pipe or other approved manner to a storm sewer or to a channel at the bottom of a ravine or steep slope.
(e) Hydrological Control Plan. A hydrological control plan, prepared by a registered professional civil engineer or landscape architect, shall be submitted with each application for a hillside protection permit. This plan shall include the following:
(1) Hydrologic inventory. A reasonably detailed description of:
A. The direction of flow within the local drainage basin;
B. All natural drainage channels directed toward and away from the site within fifty feet of the perimeter of the site;
C. Other natural drainageways which may affect or be affected by the proposal; and
D. Any future realignment of the natural ravine channel.
(2) Special notations. Special notations shall be included highlighting details of the terrain, existing natural surface drainage and areas subject to seepage or spring flow.
(3) Proposed facilities. The location of all surface and subsurface drainage devices and protective measures to be installed as part of the proposed development, together with a statement concerning any active erosion occurring at the outlet of existing or proposed systems.
(f) Vegetation and Revegetation. The following standards shall apply to vegetation and revegetation:
(1) Schedule. The percent of each parcel to remain in an undisturbed state shall be determined by the average percent of slope within each parcel to be developed. The following schedule shall apply to development in hillside areas:
Average Percent (%) Slope of Parcel | Minimum Percent (%) of Parcel To Be Undisturbed |
12-18 |
65 |
19-24 |
73 |
25-30 |
81 |
31-35 |
89 |
36-100 |
97
|
(2) Smallest area. The smallest practical area of land shall be exposed in any given time during development. Such exposure shall be kept to as short a duration of time as practical.
(3) Temporary measures. Where required, temporary vegetation, mulch or other acceptable cover shall be used to protect areas exposed during development and to prevent airborne or waterborne transportation of soil.
(4) Revegetation. A mix of plantings (preferably native with adequate deep root systems) shall be used to landscape steep slope areas disturbed by earth moving and construction.
(g) Landscape Plan. A landscape plan, prepared or approved in writing by a professional registered landscape architect trained and experienced in both the characteristics of plant material and proper procedures for installation, shall be submitted with each application for a hillside protection permit. This plan shall include the following:
(1) Existing inventory. A site plan inventory describing the existing vegetation cover of the property and showing those areas where the vegetation will be removed as part of the proposed development.
(2) Revegetation. A site plan describing proposed revegetation of disturbed areas and specifying the materials to be used.
(3) Written description. A detailed description of any slope stabilization and revegetation methods, together with the rationale for selecting the plant materials and planting techniques to be used.
(h) Excluded Activities.
Landscaping. This chapter shall not be interpreted to prohibit normal landscape maintenance or routine arboreal activities or to prohibit small scale planting of ornamental flowers or shrubs, or the removal of diseased, dead or damaged trees. However, such activities shall be carried out to conformance with the standards of vegetation or revegetation of this Chapter.