For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
BUILT-UPON AREA (BUA). That portion of a development project that is covered by impervious or partially impervious surface including, but not limited to, buildings, pavement and gravel areas such as roads, parking lots, and paths; and recreation facilities such as tennis courts. BUILT-UPON AREA
does not include a wooden slatted deck, the water area of a swimming pool, or permeable pavement that meets the standards outlined in the North Carolina Division of Water Quality Stormwater Best Management Practices Manual.
DENSITY. The calculation of the total impervious area of a project divided by the total project area. Surface water bodies shall be included in calculations of project density.
DEPARTMENT. The North Carolina Department of Environment and Natural Resources.
DESIGN MANUAL. The North Carolina Department of Environment and Natural Resources, Division of Water Quality Stormwater Best Management Practices Manual approved for use in Phase II jurisdictions by the Department for the proper implementation of the requirements of the federal Phase II stormwater program. All references herein to the Design Manual are to the latest published edition or revision.
DEVELOPMENT. Any land-disturbing activity that increases the amount of built-upon area or that otherwise decreases the infiltration of precipitation into the soil.
DIVISION. The Division of Water Quality in the North Carolina Department of Environment and Natural Resources.
FLOOD PROTECTION ZONE. The FEMA 100-year floodplain as identified on the current Flood Insurance Rate Map (FIRM) published by FEMA.
HIGH-DENSITY PROJECT. A project is a high-density project if it has more than 24% built-upon area (BUA) based on total project acreage for all residential and non-residential development. Any project that exceeds the low-density threshold for built-upon area.
IMPERVIOUS AREA. Those surfaces which prevent the infiltration of or impede the rate of infiltration of stormwater into the soil as compared with the natural conditions prior to development. Common IMPERVIOUS AREAS include, but are not limited to, compacted surfaces used for pedestrian and vehicular travel or parking and other surfaces which prevent or impede the natural infiltration of stormwater runoff that existed prior to development.
LARGER COMMON PLAN OF DEVELOPMENT OR SALE. Any area where multiple separate and distinct construction or land-disturbing activities will occur under one plan. A plan is any announcement or piece of documentation (including but not limited to a sign, public notice or hearing, sales pitch, advertisement, loan application, drawing, permit application, zoning request, subdivision application or computer design) or physical demarcation (including but not limited to boundary signs, lot stakes, or surveyor markings) indicating that construction activities may occur on a specific plot.
LOW-DENSITY PROJECT.
(1) A project is a LOW-DENSITY PROJECT if it has more than 15% built-upon area (BUA) and no more than 24% built-upon area (BUA) based on total project acreage for all residential and non-residential development.
(2) A project with an overall density at or below the relevant low-density threshold, but containing areas with a density greater than the overall project density, may be considered low density
as long as the project meets or exceeds the post-construction model practices for LOW-DENSITY PROJECTS and locates the higher density in upland areas and away from surface waters and drainage ways to the maximum extent practicable.
NON-STRUCTURAL BMP. A practice that is intended to reduce the impacts of stormwater runoff by minimizing pollution at the source and that is not a physical device constructed to control or treat stormwater runoff. Examples of NON-STRUCTURAL BMPs include reducing impervious areas, making use of existing natural features and systems, reforestation, and cluster development.
ONE-YEAR, 24-HOUR STORM. The surface runoff resulting from a 24-hour rainfall of an intensity expected to be equaled or exceeded, on average, once in 12 months and with a duration of 24 hours.
OWNER. The legal or beneficial owner of land, including but not limited to a mortgagee or vendee in possession, receiver, executor, trustee, or long-term or commercial lessee, or any other person or entity holding proprietary rights in the property or having legal power of management and control of the property. OWNER shall include long-term commercial tenants; management entities, such as those charged with or engaged in the management of properties for profit; and every person or entity having joint ownership of the property.
PERENNIAL OR INTERMITTENT SURFACE WATERS. A PERENNIAL OR INTERMITTENT SURFACE WATER shall be deemed present if the feature is approximately shown on either the most recent version of the soil survey map prepared by the Natural Resources Conservation Service of the United States Department of Agriculture (USDA) or the most recent version of the 1:24,000 scale (7.5 minute) quadrangle topographic maps prepared by the United States Geologic Survey (USGS). An exception to this requirement shall be allowed when surface waters are not present in accordance with the provisions of 15A NCAC 2B .0233(3)(a) or similar site-specific determination made using Division-approved methodology.
PERMEABLE PAVEMENT. An alternative to conventional concrete and asphalt paving materials that allows for infiltration of storm water into a storage area, with void spaces that provide temporary storage.
REDEVELOPMENT. Any development on previously-developed land, other than a rebuilding activity that results in no net increase in built-upon area and provides equal or greater stormwater control than the previous development.
RIPARIAN BUFFER ZONE. Any area extending 50 feet landward of all perennial and intermittent surface waters.
STORMWATER ADMINISTRATOR. The official, including the official’s duly authorized agent or delegate, charged with the administration and enforcement of this chapter, which includes but is not
limited to the responsibility to make decisions about stormwater permits, the design, implementation and performance of structural and non-structural BMPs; to make determinations and render interpretations of this chapter; to establish application requirements and schedules; to enforce the provisions of this chapter, and to designate appropriate other person(s) who shall carry out the powers and duties of the Stormwater Administrator.
STORMWATER MANAGEMENT PRACTICE. Any practice designed to reduce the impacts of stormwater runoff, including both structural and non-structural BMPs.
STRUCTURAL BMP. A physical device designed to trap, settle out, or filter pollutants from stormwater runoff; to alter or reduce stormwater runoff velocity, amount, timing, or other characteristics; to approximate the pre-development hydrology on a developed site; or to achieve any combination of these goals. STRUCTURAL BMP includes physical practices such as constructed wetlands, vegetative practices, filter strips, grassed swales, and other methods installed or created on real property.
SUBSTANTIAL PROGRESS. For the purposes of determining whether sufficient progress has been made on an approved plan, one or more of the following construction activities toward the completion of a site or subdivision plan shall occur: obtaining a grading permit and conducting grading activity; or installation and approval of on-site infrastructure; or obtaining a building permit for the construction and approval of a building foundation. SUBSTANTIAL PROGRESS for purposes of determining whether an approved plan is null and void is not necessarily the same as “substantial expenditures” used for determining vested rights pursuant to applicable law.
TEN-YEAR, 24-HOUR STORM. The surface runoff resulting from a 24-hour rainfall of an intensity expected to be equaled or exceeded, on average, once in ten years and with a duration of 24 hours.
TWO-YEAR, 24-HOUR STORM. The surface runoff resulting from a 24-hour rainfall of an intensity expected to be equaled or exceeded, on average, once in two years and with a duration of 24 hours.
ULTRA LOW-DENSITY PROJECT. A project that has 15% or less built-upon area (BUA) based on total project acreage for all residential and nonresidential development. A project with an overall density at or below the relevant ultra low-density threshold, but containing areas with a density greater than the overall project density, may be considered ultra low-density as long as the project meets or exceeds the post-construction model practices for ULTRA LOW-DENSITY PROJECTS and locates the higher density in upland areas and away from surface waters and drainageways to the maximum extent practicable.
(Ord. 2010-27, passed 1-6-2010)