The following words, terms and phrases, when used in this article, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning:
Applicant means an owner or developer of a site who executes the stormwater permit application pursuant to this article.
Built upon area (BUA) means impervious surface and partially impervious surface to the extent that the partially impervious surface does not allow water to infiltrate through the surface and into the subsoil, as defined in G.S. 143.214.7. "Built-upon area" does not include:
(2) The water area of a swimming pool.
(3) A surface of number 57 stone, as designated by the American Society for Testing and Materials, laid at least four inches thick over a geotextile fabric.
(4) A trail as defined in G.S. 113A-85 that is either unpaved or paved as long as the pavement is porous with a hydraulic conductivity greater than 0.001 centimeters per second (1.41 inches per hour).
(5) Landscaping material, including, but not limited to, gravel, mulch, sand, and vegetation, placed on areas that receive pedestrian or bicycle traffic or on portions of driveways and parking areas that will not be compacted by the weight of a vehicle, such as the area between sections of pavement that support the weight of a vehicle.
(6) Artificial turf, manufactured to allow water to drain through the backing of the turf, and installed according to the manufacturer's specifications over a pervious surface.
Channel bank means the location of the upper edge of the active channel above which the water spreads into the overbanks on either side of the channel or the elevation of the two-year frequency storm. Where the channel bank is not well defined, the channel bank shall be considered the edge of the waterline.
Design storm means the specific frequency and, if necessary, duration of the rainfall event to be used in design to meet the criteria established in the Administrative Manual.
Development means, consistent with the definition in G.S. 143-214.7(a1)(1), any land-disturbing activity that increases the amount of built-upon area or that otherwise decreases the infiltration of precipitation into the subsoil. When additional development occurs at a site that has existing development, the built-upon areas of the existing development shall not be included in the density calculations for additional stormwater control requirements, and stormwater control requirements cannot be apply retroactively to existing development, unless otherwise required by federal law.
Drainage structures include swales, channels, storm sewers, curb inlets, yard inlets, culverts and other structures designed to convey stormwater.
Environmentally sensitive (ES) area district is defined in section 14-103 of the Land Development Code.
Existing development means an individual nonresidential site with site plan approval by the planning department or a nonresidential or residential subdivision with preliminary subdivision approval from the planning board prior to August 1998.
Existing built-upon area means built-upon area previously approved in a stormwater management plan or in place prior to August 1998.
Illegal discharge means any unlawful disposal, placement, emptying, dumping, spillage, leakage, pumping, pouring, or other discharge of any substance other than stormwater into a stormwater conveyance system, the waters of the state or upon the land such that the substance is likely to reach a stormwater conveyance system or waters of the state and constitutes an illegal discharge.
Impervious surface is no longer the operative term, and has been replaced by the term built upon area, which is defined above.
Land disturbing activity means any use of the land that results in a change in the natural cover or topography that may cause or contribute to sedimentation.
Natural drainageway means an incised channel with a defined channel bed and banks that are part of the natural topography. Construction channels such as drainage ditches shall not be considered a natural drainageway unless the constructed channel was a natural drainageway that has been relocated, widened, or otherwise improved.
Primary stormwater control measure (SCM) means a wet pond, stormwater wetland, infiltration system, sand filter, bioretention cell, permeable pavement, green roof, rainwater harvesting, or an approved new stormwater technology that is designed, constructed and maintained in accordance with the North Carolina Department of Environmental Quality's Minimum Design Criteria (MDC).
Redevelopment means, as defined in G.S. 143-214.7(a1)(2), any land disturbing activity that does not result in a net increase in built upon area and that provides greater or equal stormwater control to that of the previous development.
Riparian buffer, see section 14-105.
Stormwater means surface water flow resulting from and occurring after any form of precipitation.
Stormwater administrator means the person designated by the county manager to have authority to review and approve stormwater permits and stormwater management plans. The stormwater administrator or designee shall also be responsible for inspecting development and enforcing the provisions of this article.
Stormwater control measure (SCM) means a permanent structural device that is designed, constructed, and maintained to remove pollutants from stormwater runoff by promoting settling or filtration; or to manage the quantity of runoff by mimicking the natural hydrologic cycle through infiltration, evapo-transpiration, post-filtration discharge, reuse of stormwater, or a combination thereof. SCMs include primary devices and secondary devices.
Stormwater conveyance system or structure means any feature, natural or manmade, that collects and transports stormwater, including, but not limited to, roadways with collection systems, catch basins, manmade and natural channels, streams, pipes and culverts, and any other structure or system designed to transport runoff.
The Administrative Manual means the Johnston County Stormwater Design and Sedimentation and Erosion Control Manual.
Vegetative buffer means an area that has a dense ground cover of herbaceous or woody species, which provides for diffusion and infiltration of runoff and filtering of pollutants.
(Ord. of 7-10-2000, § 9.3; Ord. of 1-2-2001, § 9.3; Amend. of - - ; Amend. of 9-2-2025)
Cross reference—Definitions generally, § 1-2.