2.0 Current Environmental Regulations
As previously noted, the Town of Huntersville has adopted a series of environmental regulations that serve to minimize environmental impact associated with land development. A summary of these regulations is explained in the following outline:
2.1 Mountain Island Lake Watershed Overlay District (MIL-O)
Adopted in 1993, the MIL-O District is intended to provide for the protection of public water supplies as required by the “NC. Water Supply Watershed Classification and Protection Act.” The District includes two sub-areas, “Critical” and “Protected,” with limitations established on uses, maximum impervious coverage, and buffer protection. The MIL-O District serves to limit environmental (i.e. water quality, shoreline and habitat) impacts within the district, including land areas within most of the Town’s “Nature Preserves.”
2.2 Lake Norman Watershed Overlay District (LN-O)
The LN-O District serves a similar role to that of the MIL-O District. As with the MIL-O District, the LN-O District includes both “Critical” and “Protected” areas, along with restrictions on use, impervious coverage and buffer protection.
Similar to the MIL-O District, the LN-O District provides valuable water quality protection along with preservation and protection of shorelines for Lake Norman, its tributaries and their associated habitats.
2.3 Tree Preservation
According to the “Purpose” section of the Town’s “Tree Preservation, Protection and Removal” Ordinance, “Wooded sites provide distinct aesthetic, economic and environmental significance and value as a natural resource of the Town. Existing vegetation plays a critical role in maintaining aesthetics, water quality, minimizing erosion and downstream flooding, and increasing quality of life.” Approved in 2003, the ordinance requires a site analysis for all development in residential and commercial zoning districts, with specific tree preservation standards for significant forest stands, specimen trees and heritage trees. According to the ordinance, 100% of Heritage Trees shall be preserved, 10% to 50% of Specimen Trees and between 10% and 50% of the existing tree canopy shall be preserved, depending on the specific zoning district. In instances where tree preservation standards cannot be met, replanting or contribution to a Tree Fund/Bank is required to offset the loss of trees if approved by the Planning Board. (Source: Article 7.4, Huntersville Zoning Ordinance)
2.4 Buffer Yards & Landscaping
In addition to its tree preservation requirements, the Town requires buffer yards to provide visual and distance separation between adjacent properties, except those located within the Town Center (TC) and Transit Oriented Development (TOD) zoning districts. The Town also requires the planting of street trees along public and parking lots to ensure: “a pedestrian friendly environment along with providing distinct aesthetic, economic and environmental significance, and value as a future natural resource to the Town.”
(Source: Article 7.7, Huntersville Zoning Ordinance)
2.5 Open Space
The Town’s development regulations require the provision of Urban Open Space and Natural Recreational and Agricultural Open Space for most development proposals. Urban Open Space is defined as “all areas not divided into private or civic building lots, streets, right-of-way, parking or easements for purposes other than open space conservation.”
Urban Open Space is required in all zoning districts except Rural and can consist of squares, parks, forecourts, plazas, parkways and greenbelts.
(Source: Article 7.10, Huntersville Zoning Ordinance)
The purpose of Natural Recreational and Agricultural Open Space in the Rural and Transitional zones is to preserve agricultural and forestry lands, natural and cultural features, and rural character that would likely be lost through conventional development approaches. Lands to be preserved as open space should include wetlands and the areas immediately adjacent to them; floodways; soils unsuitable for septic systems; mature woodlands; significant wildlife habitat; prime agricultural farmland; historic, archaeological and culture features listed (or eligible to be listed) on national, state or local registers or inventories; significant views into and out from the site; and aquifers and their recharge areas. The subdivision process is discussed in Section 3.0 of this focus area.
2.6 Water Quality
In 2003, the Town adopted “Water Quality” regulations consistent with the National Pollution Discharge Elimination System (NPDES) Storm Water Permit and other requirements as established by the U.S Clean Water Act. The purpose of these regulations is to establish storm water management requirements and controls to prevent surface water quality degradation to the extent practicable in the streams and lakes within the Town Limits.
Compliance with the Town’s Water Quality standards requires the use of “Low Impact Development (LID),” which seeks to more closely replicate a site’s predevelopment characteristics (i.e. ecology) as compared to conventional storm water management techniques. “The goal of LID is to develop site design techniques, strategies, and ‘Best Management Practices’ (BMPs) to store, infiltrate, evaporate, retain, and detain runoff on the site to more closely replicate pre-development runoff characteristics and to better mimic the natural and unique hydrology of the site thereby limiting the increase in pollutant loads caused by development.”
(Source: Article 8.17.13 - Huntersville Zoning Ordinance )
An excellent example of the application of LID principles to an existing development is depicted in Figure E-2. This picture shows the retrofit of an existing shopping center parking lot to reduce the amount of impervious area through the removal of parking spaces and replacement with rain gardens. Rain gardens are vegetated areas which allow for the infiltration of storm water runoff. These rain gardens serve to allow for on-site recharge of the water table, as well as filtration of surface pollutants, such as engine oil and sediments.
Figure E-2 - Retrofit of Rain Garden in Parking Lot at Northcross Shopping Center
2.7 Surface Water Improvement & Management (S.W.I.M.) Stream Buffers
Adopted in 2001, the purpose of S.W.I.M. Stream Buffers are “to filter pollutants, store floodwaters, provide habitat, and contribute to the ‘green infrastructure.’ Stream systems are comprised of each stream and its respective drainage basin”. (Source: Article 8.25, Huntersville Zoning Ordinance) (Map E-1 shows the S.W.I.M.. buffers within the Town of Huntersville shaded in blue.) The S.W.I.M. buffers include all perennial and intermittent streams within the Town’s jurisdiction, and consist of a “minimum” 30 foot buffer extending outward from the top of a stream bank. The width of the S.W.I.M. buffer is based on the total drainage basin size and covers three zones, as noted in Table E-2.
Table E-2 S.W.I.M. Stream Buffers - Minimum Buffer Widths by Basin Size & Buffer Zone
|Basin Area||Stream Side Zone||Managed Use Zone||Upland Zone||Total Buffer (each side of stream)|
|<50 acres||N/A||N/A||30 feet||30 feet|
|>50 acres||20 feet||N/A||15 feet||35 feet|
|>300 acres||20 feet|| 20 feet||10 feet||50 feet|
|>640 acres||30 feet|| 45 feet||25 feet or balance of flood plain||100 feet or entire flood plain|
Source: Article 8.25, Huntersville Zoning Ordinance
Within each zone there are restrictions on uses allowed, as well as on the disturbance of vegetation and alteration of terrain.