§ 34-2. Definitions.
The following words, terms and phrases, when used in this chapter, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning. All other words used in this chapter shall have their common, dictionary definition, unless specifically defined with a meaning ascribed to them in the other chapters of the town Code of Ordinances.
Base flood elevation (BFE): means a determination of the water surface elevations of the base flood as published in the flood insurance study and in accordance with the town's flood damage prevention ordinance (chapter 22).
Best management practices or BMPs: also known as stormwater control measures (SCM) or stormwater management practices, are techniques implemented as a way of treating or limiting pollutants and other damaging effects of stormwater runoff in order to meet legislative and North Carolina Administrative Code requirements. This term means a permanent stormwater device that is designed, constructed, and maintained to remove pollutants from stormwater runoff by promoting settling or filtration; or to mimic the natural hydrologic cycle by promoting infiltration, evapo-transpiration, post-filtration discharge, reuse of stormwater, or a combination thereof. Common stormwater control measures include, but are not limited to: infiltration systems, permeable pavements, stormwater wetlands, wet ponds, bioretention cells and vegetative treatment swales.
Built-upon area (BUA): that portion of a development project that is covered by impervious materials or partially impervious surfaces and used to calculate stormwater runoff potential, including buildings; pavement and compacted gravel areas such as roads or parking lots, and paths and recreation facilities such as athletic courts and concrete pool decks. Built-upon area does not include the surface area of pools, wooden slatted decks, or un-compacted, washed gravel, or pervious or partially pervious paving material to the extent that the paving material absorbs water or allows water to infiltrate through the paving material. Built-upon area is distinct from "lot coverage" as calculated under the zoning ordinance (chapter 48).
Design storm or design depth: rainfall event, expressed in depth, measured in inches, for the purposes of this chapter and independent of storm duration, utilized for the calculation of storage volume required for BMPs. Design storm depth varies by flood zone and use as specified in this chapter.
Development: any land disturbing activity that increases the amount of built-upon area or that otherwise decreases the infiltration of precipitation into the soil, including buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment or materials, not including existing residential or commercial development already in place.
Drainage area: the entire area contributing surface runoff to a point of interest.
Fill: the depositing of soil, rock or other earthen materials by artificial means, but not including poured slab, asphalt, porous pavement, Turfstone TM , or other manmade materials or surfaces designed in association with construction.
Fill depth: the difference between the post-development surface elevation and the pre-development surface elevation.
Grading: any cut or fill, or combination thereof, or re-compaction of soil, rock or other earthen materials.
Impacts of stormwater: impacts associated with inadequate storage, conveyance, or ponding of stormwater runoff, including erosion, intermittent flooding, or chronic flooding.
Impervious surface: any surface which, because of its material composition or compacted nature, impedes or prevents natural infiltration of stormwater into the soil.
Lot balancing: the act of grading a site utilizing existing on-site material for purposes such as providing a level building pad or vehicular areas. Lot balancing does not include the importation of fill.
Lot coverage: that portion of the lot area, expressed as a percentage, that is occupied and obstructed by any structure above the ground including, buildings, decks, parking areas, access ways, sidewalks and roadways, and all accessory uses and structures requiring location on or above the ground. Lot coverage is utilized to determine zoning compliance and is distinct from the amount of built upon area used in stormwater management calculations.
Low impact development: a stormwater management design framework aimed at minimizing the negative impacts of stormwater runoff by mimicking pre-development hydrology.
Low Impact Development Solutions to Reduce Stormwater Runoff, or the town BMP Manual: the local reference guide designed to provide information for low impact development practices and which can be utilized to assist with compliance for residential projects using two feet or less of fill under this chapter. All references herein to the town BMP Manual or "Low Impact Development Solutions to Reduce Stormwater Runoff," are to the latest edition or revision.
North Carolina Stormwater Best Management Practices Manual or NCDENR BMP Manual: the Stormwater Design Manual approved by North Carolina. All references herein to the NC BMP Manual are to the latest published edition or revision.
Operations and maintenance agreement: the owner's document that is filed with the town at the time of the certificate of compliance which provides BMP maintenance instructions and inspection schedule.
Permeable pavement: paving materials that absorb water or allow water to infiltrate through the paving material. Permeable pavement materials include porous concrete, permeable interlocking concrete pavers, concrete grid pavers, Turfstone TM , and other proven technologies available as covered in the NC BMP manual and as approved by the town engineer as appropriate to the existing conditions for the site of application. Compacted gravel shall not be considered permeable pavement.
Post-development surface elevation: the finished or final land surface grades recorded at the completion of construction activities.
Pre-development surface elevation: the land surface grades existing prior to any land disturbing or grading activities.
Redevelopment: any development activity that physically alters an existing developed site.
Site element: improvements to the existing land form for the purposes of development to include buildings, pavement, decks, landscaping, pools or other accessory structures.
Stormwater management system: refers to a drainage network or series of best management practices working together as part of a comprehensive approach to handling stormwater.
Stormwater retrofit: implementation of stormwater management for an existing site, which previously had no stormwater management measures in place, measures inadequate to meet the stormwater management requirements of the ordinance codified herein, or measures inadequate to meet other stormwater management goals or requirements.
Stormwater runoff: flow of surface water resulting from precipitation and distinct from runoff created by human activity such as pumping or draining.
(Ord. No. 17-12-020 , Pt. I, 12-6-2017; Ord. No. 18-12-017 , Pt. I, 12-5-2018)