3.3.3-A Critical Area (CA)
Intent: The intent of these regulations is to require higher standards in the Critical Area of the Lake Norman Watershed because of the greater risk of water quality degradation from pollution. All uses permitted in the Critical Area for which erosion/sedimentation control plans are required under Town of Huntersville regulations are subject to the standards of both the overlay district and the underlying zoning district. In every case the more restrictive standard controls.
a) Permitted Uses
Uses permitted with conditions
- essential services 1 and 2, provided that there shall be no new industrial process or domestic discharges into any stream or lake in the Lake Norman Watershed, but existing wastewater treatment plant(s) may expand so long as the total pollutant load per parameter will not be increased beyond the effluent limits permitted as of October 1, 1993, the effective date of watershed protection regulations;
- agriculture, subject to the provisions of the Food Security Act of 1985 and the Food, Agricultural, Conservation and Trade Act of 1990. All agricultural activities conducted after January 1, 1993 shall maintain a minimum ten foot vegetative buffer, or equivalent control as determined by the Soil and Water Conservation Commission, along all perennial waters indicated on the most recent versions of U.SG.S 1:24,000 scale topographic maps or as determined by local government studies. Agricultural activities begun after October 1, 1993 shall comply with the buffer standards of Section 3.3.3-A(f). Animal operations greater than 100 animal units shall employ Best Management Practices by July 1, 1994 recommended by the Soil and Water Conservation Commission;
- silviculture, subject to the provisions of the Forest Practices Guidelines Related to Water Quality (02 NCAC 60C.0100 to .0209);
- residential uses permitted in the underlying district, subject to either the low or high density option; cluster development allowed in the underlying district is permitted;
- non-residential uses permitted in the underlying district, subject to either the low or high-density development option; cluster development allowed in the underlying district is permitted.
b) Prohibited Uses
- all uses not permitted in the underlying zoning district
- residual applications
- landfills, sanitary
- landfills, off-site demolition
- new or expanded domestic and industrial discharges
- disposal or treatment of petroleum contaminated soils (land farming)
- petroleum storage tanks as a principal use
c) Permitted Building and Lot Types
- building and lot types permitted in the underlying zoning district
d) Permitted Accessory Uses
- accessory uses permitted in the underlying zoning district; uses prohibited as principal uses are also prohibited as accessory uses
e) Built-Upon Area (BUA) Development Standards
For individual buildings or for development projects within the Lake Norman Critical Area, the following impervious area limitations are established on a building or project basis.
|CA, low density option||24% B.U. 1|
|CA, high density option||50% B.U. with Structural BMP 1|
1 Residential subdivisions shall reserve, at minimum, 1% of the lot area but not less than 150 square feet impervious area per lot to allow for addition of future impervious areas by homeowner/occupant
f) Buffer Size
Undisturbed buffers, except as specifically provided in this section, are required along the shoreline of Lake Norman measured horizontally by a licensed land surveyor from the normal pool elevation (760’ contour) and along each side of all perennial streams measured from the top of the bank on each side on the stream. Minimum buffer widths are:
|CA, low density option||50 feet|
|CA, high density option||100 feet|
g) Buffer Protection
No permanent structures, impervious covers, septic tank systems or any other disturbance of existing vegetation shall be allowed within the buffer except as follows:
- The surveyed buffer boundary must be clearly marked on-site with orange “tree-protection” or “high-hazard” fence prior to any land disturbing activities. Tree protection is required by Section 7.4(3) of this Ordinance.
- The surveyed buffer boundary must be permanently marked with an iron pin at the intersection of the watershed buffer and each property line following the completion of land disturbing activities and prior to occupancy. Properties greater than 200’ in width shall be marked at a maximum of 100’ intervals.
- No trees larger than 2-inch caliper, measured at 6 inches above the existing grade, are to be removed except for dead or diseased trees. Undergrowth and trees less than 2-inch caliper, measured at 6 inches above the existing grade, may be removed to be replaced by an effective stabilization and filtering ground cover based upon the most recent edition of the “Charlotte-Mecklenburg Water Quality Buffer Implementation Guidelines” and as approved by Charlotte-Mecklenburg Storm Water Services.
- Stream bank or shoreline stabilization is allowed as approved on a plan submitted to the Town Engineering Department and the Charlotte-Mecklenburg Storm Water Services.
- Water dependent structures and public projects such as road crossings and greenway paths are allowed where no practical alternatives exist. These activities should minimize built-upon area, direct runoff away from surface waters, and maximize the utilization of nonstructural BMPs and pervious materials.
- During new development or the expansion of existing development, the Town, upon the advice of the Charlotte-Mecklenburg Storm Water Services, can require enhancement of the existing vegetation in the buffer if necessary so that the buffer can effectively perform its filtering and absorption functions. Buffer enhancement requirements shall be based on the most recent edition of the “Charlotte-Mecklenburg Water Quality Buffer Implementation Guidelines”.
- Mitigation of disturbed buffers required. Should existing vegetation within the buffer be disturbed (except as allowed by this Ordinance) or should vegetation added to a buffer pursuant to paragraph 6) be disturbed, the property owner shall be required to enhance the buffer in accordance with the most recent edition of the “Charlotte-Mecklenburg Water Quality Buffer Implementation Guidelines” so that the buffer can effectively perform its filtering and absorption functions.
- Non-impervious recreational development and non-impervious pedestrian trails are allowed in the required buffer in compliance with paragraph 3), above. Pathway guidelines are available in the most recent edition of the “Charlotte-Mecklenburg Water Quality Buffer Implementation Guidelines.” If in a common area, such development and trails must be located a minimum of 30 feet from the normal pool elevation of Lake Norman (760’ contour), or a minimum of 30 feet from the top of the bank on each side of all perennial streams; except for waterfront access points approved by the Town, upon the advice of the Charlotte-Mecklenburg Storm Water Services.
h) High Density Option Requirements in the Critical Area of the LN Watershed
- The High-Density Option allows for greater development density provided engineered controls (structural BMPs) are used to manage storm water runoff. Structural BMPs are required under the High-Density Option. The High-Density Option is permitted in the CA subarea. In addition to meeting basic zoning and subdivision standards of the Town of Huntersville, high-density development shall meet the requirements of this section, the Land Development Standards Manual, other published standards of the Town Engineering Department.
- High Density Permit Application.
a. A High-Density Development Permit shall be required for new development exceeding the requirements of the low-density option.
b. Application for a High-Density Development Permit shall be submitted as follows:
i. Development plans subject to the Huntersville Subdivision Ordinance and the Sediment and Erosion Control Ordinance will submit the High-Density Development Permit to the Town Engineering Department and the Huntersville Planning Director, or designee, as part of the subdivision review application process.
ii. Development plans exempt from subdivision ordinance regulations will submit the High-Density Development Permit to the Town Engineer or their designee as part of the Sediment and Erosion Control requirements of the building permit application process.
iii. Applications for the High-Density Option shall be made on the proper form and shall include the following information:
- A completed High-Density Development Permit Application signed by the owner of the property. The signature of the consulting engineer or other agent will be accepted on the application only if accompanied by a letter of authorization.
- Required number of development plans and specifications of the storm water control structure.
- Submittal of a sediment and erosion control plan to the appropriate agency.
- Permit application fees.
3) Structural BMPs.
- All structural BMPs shall be designed, and the plans sealed, by a North Carolina registered professional with qualifications appropriate for the type of system required as provided for in the North Carolina General Statues.
(b) Structural BMPs shall be designed for specific pollutant removal according to modeling techniques approved by the North Carolina Division of Water Quality. Specific requirements for these systems shall be in accordance with the design criteria and standards contained in the Land Development Standards Manual.
(c) Qualifying areas of the structural BMP may be considered pervious when computing total built-upon area. However, if the structure is used to compute the percentage built-upon area for one site, it shall not be used to compute the built-upon area for any other site or area.
(d) The design of the structural BMP shall include the appropriate easements for ingress and egress necessary to perform inspections, maintenance, repairs and reconstruction.
4) Posting of Financial Security Required.
When Structural BMPs are required under the High Density Option, the approval of the High Density Development Permit will be subject to developer compliance Section 8.400 of the Huntersville Subdivision Ordinance.
5) Additional Requirements.
(a) An Occupancy Permit shall not be issued for any building within the permitted development until the Town Engineering Department has approved the storm water control structure.
(b) Appeals of any order, requirement, decision or determination shall be made to and decided by the Zoning Board of Adjustment of the Town of Huntersville.
i) Paired-Parcel Averaged-Density Development
Paired-parcel averaged density development involves the transfer of impervious development rights between two (2) parcels not within the boundaries of the same subdivision by way of designated undisturbed natural areas. A metes and bounds description of the space to be undisturbed and limits on use shall be recorded on the subdivision plat, in homeowner covenants, and on individual deed and shall be irrevocable. The resultant impervious area/amount for the two lots combined shall not exceed the original allowable impervious amount for each individual lot if they were developed separately.
1. A density averaging certificate shall be considered one development request.
2. Overall impervious area/amount of the paired parcel averaged-density development, calculated by built-upon area, shall not exceed the impervious that would be allowed if the parcels were developed separately. The parcel pair shall be located in the same water supply watershed and preferably in the same drainage area of the watershed. Parcel pairs may be located in the Critical Area and in the Protected Area. However, if one of the parcels is located in the Critical Area and one is located in the Protected Area, the Critical Area parcel shall not be developed beyond those impervious amounts allowed in the critical area provisions of the Huntersville Zoning Ordinance. A property in a more restricted watershed area shall not acquire impervious rights from a property in a less restricted area of the watershed. The purpose of this provision is to preserve open space in the more sensitive areas of the watershed.
3. The paired parcels may include or be developed for residential or non-residential purposes.
4. Buffers shall at least meet the appropriate minimum Huntersville Zoning Ordinance water supply watershed protection requirements on both parcels in the parcel pair.
5. The portion of the parcel(s) which is not developed as part of the paired parcel, but that is being averaged in the land area being evaluated to meet the built-upon surface area, shall remain in an undisturbed vegetated or natural state. A metes and bounds description of the space to be undisturbed and limits on use shall be recorded on the subdivision plat, in homeowner covenants, and on individual deed and shall be irrevocable. The resultant impervious area/amount for the two lots combined shall not exceed the original allowable impervious amount for each individual lot if they were developed separately. It shall be noted on the plat that the Zoning Administrator shall reserve the right to make periodic inspections to ensure compliance.
6. A Density Averaging Certificate shall be obtained from the Watershed Review Board (Board of Adjustment) to ensure that both parcels considered together meet the standards of the ordinance and that potential owners have record of how the watershed regulations were applied to the parcel pair. Only the owner(s) of both of the paired parcels may submit the application for the Density Averaging Certificate. A site plan for both of the parcels must be submitted and approved as part of the Density Averaging Certificate. If such a certificate is granted, no change in the development proposal authorized for either parcel shall be made unless the certificate is amended. Upon issuance of such certificate, one copy will be forwarded to the North Carolina Division of Water Quality (DWQ). Included with the Density Averaging Certificate will be a site plan, registered plats for both properties, a description of both properties, and documentation reflecting the development restrictions to the parcel pair that will remain undeveloped.
7. The Watershed Review Board shall make written findings supported by appropriate calculations and documentation that the paired parcel averaged-density development plan as a whole conforms to the intent and requirements of this Article and Section, and that the proposed agreement assures protection of the public interest.
8. The undisturbed land area shall be recorded in the deed for the parcel to which it applies. The Density Averaging Certificate shall be recorded in the deed for each of the parcels in the parcel pair. Both the designated undisturbed land area and the certificate shall be noted on the subdivision plat that applies to each of the parcels.
9. Stormwater runoff from paired parcel averaged density-averaged development which meets the low-density option development requirements shall be controlled by vegetative conveyances to the maximum extent practicable and shall be approved by the Town of Huntersville.
10. Stormwater runoff from paired parcel averaged density development which meets the high-density option development requirements shall be controlled on the parcel(s) where the high-density development is occurring in accordance with the criteria specified in the Huntersville Water Quality Design Manual and the Huntersville Zoning Ordinance for high-density development.
11. No parcel for which a watershed variance has been granted, or would be required, may be included as part of a parcel pair.
12. Compliance with criteria 1-12 shall be evidence that the parcel pair is consistent with the orderly and planned distribution of development throughout the watershed.