§ 21-33. Overlay districts.
Overlay districts are zoning districts, which are applied only in conjunction with other zoning districts, and may grant additional use of development requirements upon the underlying zoning districts. The effect is to have both the overlay district and the underlying zoning controlling the use and development of the lot. Overlay districts are applicable on an area wide basis to support specific public policy objectives and as such should be consistent with adopted land use plans. Overlay districts may be applied to conventional and conditional zoning districts. An overlay district may be initiated as an amendment by the board of commissioners, planning board or property owner.
(1)
Airport zone overlay, AZO. The zones and restrictions established in this subsection are designed to limit the height of structures surrounding the county airport's established elevation of seven hundred seventy-one (771) feet above mean sea level (msl) in order to prevent hazards to the lives and property of the users of the airport and the occupants of land in the vicinity.
a.
Uses allowed. The use requirements of the underlying district apply to the AZO district. However, all uses must be in conformance with the provisions of this section.
b.
Establishment of zones. To carry out the provisions of this section, there are hereby created and established certain civil airport imaginary surfaces which include all of the land lying beneath the approach surface, transitional surface, horizontal surface, conical surface and primary surface. These civil airport imaginary surfaces are established with relation to the county airport runway and proposed extensions of thereof. Such imaginary surfaces are shown on the official county airport zoning map prepared by the county planning department and dated October 4, 2004, which is adopted and incorporated herein by reference. The size of each such imaginary surface is based on the categorization of this runway as a precision instrument runway. The slope and dimensions of the imaginary surfaces, applied to each end of a runway, are determined by the most precise approach existing or planned for the runway end. The surfaces are hereby established and defined as follows:
1.
Horizontal surface. A horizontal plane one hundred fifty (150) feet above the established airport elevation, the perimeter of which is constructed by swinging acres with a radius of ten thousand (10,000) feet from the center of each end of the primary surface of each end of the runway, including any planned extensions, and connecting the adjacent arcs by lines tangent to those arcs.
2.
Conical surface. A surface extending outward and upward from the periphery of the horizontal surface at a slope of 20:1 for a horizontal distance of four thousand (4,000) feet.
3.
Primary surface. A surface longitudinally centered on a runway. The primary surface extends two hundred (200) feet beyond each end of the runway. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway centerline. The width of the primary surface is one thousand (1,000) feet as required for precision runway landings.
4.
Approach surface. A surface longitudinally centered on the extended runway centerline and extending outward and upward from each end of the primary surface.
i.
The inner edge of the approach surface is the same width as the primary surface and it expands uniformly to a width of sixteen thousand (16,000) feet as provided for precision instrument runways.
ii.
The approach surface extends for a horizontal distance of ten thousand (10,000) feet at a slope of 50:1 with an additional forty thousand (40,000) feet at a slope of 40:1.
5.
Transitional surface. These surfaces extend outward and upward at right angles to the runway centerline and the runway centerline extended at a slope of 7:1 from the sides of the primary surface and from the sides of the approach surfaces. Transitional surfaces for those portions of the precision approach surface which project through and beyond the limits of the conical surface, extend a distance of five thousand (5,000) feet measured horizontally from the edge of the approach surface and at right angles to the runway centerline.
c.
Height limitations. Except as otherwise provided in this article, no structure shall be erected, altered or maintained, and no tree shall be allowed to grow within the AZO district extending or projecting into the lowest applicable imaginary surfaces defined herein.
(2)
Water supply watershed overlays, WSO. The purpose of the watershed overlay is to provide for the protection of public water supplies as required by the Water Supply Watershed Classification and Protection Act (G.S. 143-214.5) and regulations promulgated therein. The watershed overlays may be an overlay in any conventional or conditional zoning district established in this chapter. The overlay districts supplement the uses or development requirements of the underlying zoning districts.
a.
Uses allowed. The use requirements of the underlying districts apply to the WS districts, unless otherwise provided in this section. However, all allowed uses must be in conformance with the provisions of this section.
b.
Expressly prohibited in critical areas. The following uses are expressly prohibited:
1.
Landfills;
2.
Sites for land application of sludge/residuals or petroleum contaminated soils.
c.
Calculating built-upon area. For the purpose of calculating built-upon area, total project area shall include total acreage in the lot on which the project is to be developed.
d.
Density and built-upon limits. The following density and built-upon limits shall apply to development in the water supply watersheds unless expressly provided otherwise.
Watershed
Single-family
Residential
Multi-family and
Nonresidential
Development
Watershed-II-Critical Area, WS-II-CA 80,000 sq. ft. minimum lot size or 6 percent built-upon area on a project by project basis Development shall not exceed 6 percent on a project by project basis, unless otherwise provided in this section Watershed-II-Balance of Watershed, WS-II-BW 40,000 sq. ft. minimum lot size Maximum 12 percent built-upon on a project by project basis Watershed-III-Critical Area, WS-III-CA 40,000 sq. ft. minimum lot size Maximum 12 percent built-upon on a project by project basis Watershed-III-Balance of Watershed, WS-III-BW 20,000 sq. ft. minimum lot size Maximum 24 percent built-upon area on a project by project basis Watershed-IV-Critical Area, WS-IV-CA * 20,000 sq. ft. minimum lot size Maximum 24 percent built-upon area on a project by project basis Watershed-IV-Protected Area, WS-IV-PA * 20,000 sq. ft. minimum lot size Maximum of 24 percent built-upon area with curb and gutter or 36 percent built-upon area without curb and gutter. * Development activities which require an erosion/sedimentation control plan must meet these requirements.
e.
Special nonresidential intensity allocation (SNIA) permit.
1.
Purpose. The purpose is to provide a method for the board of commissioners to allow ten (10) percent of the county's portion of the balance of watershed area (excluding a critical area) to be granted an SNIA permit to be developed at up to seventy (70) percent built-upon surface area.
2.
Application and review procedures. Applications shall include a site plan as prescribed in section 21-52.
3.
Review and approval. The site plan shall be reviewed by the board of commissioners. Approval of the plan may include the addition of reasonable and appropriate conditions.
4.
Applicable areas. Areas in which SNIA permits may be approved are as follows:
i.
WS-II-BW.
ii.
WS-III-BW.
iii.
WS-IV-PA.
5.
Eligibility for an SNIA permit. Nonresidential uses subject to compliance with section 21-113 shall be eligible unless otherwise indicated in this chapter.
(3)
Agricultural overlay, AO. The purpose of the Agricultural Overlay District is to provide additional requirements to encourage the maintenance of viable agricultural areas. This district should be comprised primarily of open farm land used for extensive agricultural and livestock production. The district will provide guidelines to promote the maintenance of the general rural character of openness. Development in this district shall be subject to the criteria below.
a.
Uses allowed. The following agricultural and related uses are allowed:
Code 1987 U.S. SIC Description 01 Agricultural production—crops 02 Agricultural production—livestock 515 Wholesale farm products and raw material part of a bona fide farm operation 5261 Retail nurseries, lawn and garden supply stores part of a bona fide farm operation Other similar agricultural uses such as feed and seeds part of a bona fide farm operation Family subdivisions of up to three (3) lots plus the remainder Family manufactured home parks of up to three (3) manufactured homes occupied by members of the immediate family of the property owner Rural home occupations 07 Agricultural services b.
Development of property not part of a bona fide farm located in AO District. Within the AO district setback of fifty (50) feet shall be provided from land in agricultural use.
(4)
Manufactured home overlay, MHO.
a.
Purpose and intent. The purpose of the manufactured home overlay is to provide for the development of type ii and type iii manufactured homes in established residential zoning districts while maintaining the overall residential, rural or agricultural character of those districts. Because of the potential impacts of the establishment of this district, it has prescribed conditions contained in this subsection to ensure compatibility with the surrounding area.
b.
Permitted districts. The manufactured home overlay supplements the range of uses and regulations in the underlying district. The overlay is allowed in the following districts permitting residential development: RA, RR, CBI and MFR. All other uses in the underlying district shall continue to remain in effect and subject to the regulations and conditions of approval of the underlying district.
c.
Procedures for district designation. The following procedures are required for MHO district designation:
1.
Designation as an MHO district shall require a rezoning as provided in article XIV of this chapter.
2.
Upon approval of an MHO district by the board of commissioners, the area so designated shall be labeled "MHO" on the zoning map.
d.
Review. The petitioner seeking to rezone property to this district must illustrate that the proposed development will comply with the evaluation criteria contained in section 21-59. A site plan is required as provided by section 21-52. In approving the district reasonable conditions may be included to protect the public health, safety and welfare and to meet the intent of this chapter.
e.
Development standards. The following standards shall apply for the location of type II and type III manufactured homes unless specifically provided otherwise in this chapter:
1.
Location of type II and type III manufactured homes on subdivisions of one (1) or more lots shall require establishment of an MHO zoning district.
2.
Upon establishment of an MHO district the following types of homes may be located in the following districts:
i.
RA district: Type II and type III.
ii.
RR district: Type II.
iii.
CBI district: Type II and type III.
iv.
MFR district: Type II and type III.
3.
The side and rear yard setbacks for the external boundary of the district is thirty (30) feet.
(Ord. of 1-19-98, § III; Ord. of 6-7-99; Ord. of 12-18-00(2); Ord. of 10-4-04; Amend. of 11-2-09; Amend. of 4-21-14; Amend. of 9-6-16)