Harnett County, NC Environmental Rules: Stormwater Management (2026)

221 triggers the stormwater subchapter for any new residential or nonresidential development or redevelopment disturbing more than one acre, or nonresidential work adding more than 22,000 square feet of disturbed area. 224 requires a stormwater management statement with the preliminary plat, covering site vicinity maps, USGS topography, impervious area calculations, watershed status, proposed Best Management Practices (BMPs), and pre- and post-development discharge comparisons for the 10-year and 25-year storms. 226 sets BMP design standards under the NC DEQ Stormwater BMP Manual, requiring drought-tolerant vegetation, side slopes no steeper than 3:1, and fencing only where public safety requires it (such as within 50 feet of a right-of-way or where the BMP is three feet deep or more).

227 requires a binding operation and maintenance agreement filed with the Register of Deeds, an annual inspection of every stormwater control structure with records kept on NCDENR-approved forms, and County Engineer notification before any repair or reconstruction; failing to maintain the required improvements is itself declared a violation of the chapter. 5% channel slope, minimum 15-inch pipe diameter, 24-inch minimum vertical separation from water and sewer lines at crossings, and design for the 10-year storm on local drainage systems. 229 requires stormwater management plans sealed by a professional engineer or surveyor showing 2-foot topographic contours, the 100-year floodplain boundary from the current FIRM, and all wetland boundaries.