(A) 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 are subject to possible slope failure and to require investigation and remediation of such conditions, if necessary, when such land is proposed to be developed. All land disturbing activities require submittal of a site plan with a scale of 1 inch=40 feet or less, with a contour interval no greater than two feet.
(B) (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.
(a) I = Contour intervals of the map in feet, with said intervals being five feet or less.
(b) L = Total length of the contour lines within the parcel in feet.
(c) A = Area of the parcel in acres.
(d) 0.0023 = The constant that converts square feet into acres.
(3) The above formula for calculating the percentage of average slope is used for determining very steep slopes and steep slopes. The maximum impervious surface allowed upon very steep slopes is limited to no more than 60% of the total surface area of the property. The maximum impervious surface allowed upon steep slopes is limited to no more than 70% of the total surface area of the property.
(4) Building height is limited upon very steep slopes to no more than 30 feet. Building height is limited upon steep slopes to no more than 35 feet. For purposes of determining building height of this section, once the placement of the footprint of a structure has been identified, the height of the building shall 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.
(C) 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 he or she may employ and/or contract with a licensed engineer whose practice includes geotechnical engineering 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. Such an evaluation may include, but not be limited to all driveways, roads, retaining walls, and other cut and fill upon 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 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 § 31.07.
(D) 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 by the applicant, and conducted by a licensed engineer whose practice includes geotechnical engineering, 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 licensed engineer whose practice include geotechnical engineering 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 affects surrounding properties.
(Res. 2024-1, passed 2-20-2024)