The intent of these regulations is to provide special measures for land development activities in areas requiring land disturbance of steep and very steep slopes, to facilitate the identification of land areas subject to possible slope failure and to require investigation and remediation of such conditions, if necessary, when such land is proposed to be developed.
(A) (1) The following categories of steep slope are hereby established:
(a) Very steep slopes are slopes steeper than 50%; and
(b) Steep slopes are slopes between 20% and 50%.
(2) Percentage of average slope is determined by the following method:
S = 0.0023 x I x LA
I = Contour intervals of the map in feet, with said intervals being 5 feet or less
L = Total length of the contour lines within the parcel in feet
A = Area of the parcel in acres
0.0023 = The constant that converts square feet into acres
(3) The above formula for calculating the percentage of average slope is used for § 152.028(C) of this chapter; which determines the amount of impervious surface allowed for percentage of slope. Once the placement of the footprint of a structure has been identified, the height of the building can be determined by the midpoint of each wall of the smallest rectangle that can be made with the entire footprint, to determine a midpoint in the center of that rectangle to be used for a measuring point to determine the height of the building.
(B) Development requirements for both steep and very steep slopes shall be as follows:
(1) All stream crossings, culverts and disturbance of riparian zones are to comply with appropriate state and federal regulations;
(2) Should the Zoning Administrator believe that geological hazard indicators are present, at the direction of the Town Manager, he or she may employ and/or contract with an independent geotechnical engineer to evaluate plans for development, as necessary, with the cost for this technical review to be borne by the person(s) requesting development of the property. Once the analysis is performed, the Zoning Administrator shall cause it to become a part of the public record.
(3) Developers of property, where the development plan requires land disturbing activity on very steep slopes, shall make reasonable effort to preserve and protect features of the slope, such as trees and other plant material, which may help to stabilize the slope.
(4) The owner of any property whose development plan will include the disturbance of a steep or very steep slope, as determined by the Zoning Administrator, may challenge this determination by appeal to the Board of Adjustment as provided in § 152.270 of this chapter.
(C) The requirements for land disturbing activities on very steep slopes shall be as follows.
(1) Plans for the development of any property must be accompanied by a site-specific geologic analysis of the very steep slope portion of the site to be disturbed by the proposed development plan, paid for the by the applicant, and conducted by a geotechnical engineer, to determine whether the proposed development plan can be implemented without jeopardizing the slope stability on the site itself or/and on properties surrounding the site.
(2) If the property is determined to be safe for development and requires remedial measures to ensure slope stability, a North Carolina registered geotechnical engineer must develop and present a plan to the Zoning Administrator that will preserve slope stability on the site during and after completion of grading and construction for the site, as well as for surrounding properties to the extent that the contemplated development activities on the site affect surrounding properties.
(Ord. passed 3-14-2005; Ord. passed 10-10-2016; Ord. passed 3-14-2019, § 310)