High-density projects shall implement stormwater control measures that comply with each of the following standards:
(a) The measures shall control and treat stormwater runoff from the first inch of rain. Runoff volume drawdown time shall be a minimum of forty- eight (48) hours, but not more than one hundred twenty (120) hours.
(b) Must discharge the storage volume at a rate equal to or less than the predevelopment discharge rate for the one (1)-year, twenty-four (24)-hour storm.
(c) All structural stormwater treatment systems used to meet these requirements shall be designed to have a minimum of eighty-five percent (85%) average annual removal for total suspended solids (TSS).
(d) General engineering design criteria for all projects shall be in accordance with 15A NCAC 2H .1008(c), as explained in the Design Manual.
(e) All built-upon area shall be at a minimum of thirty (30) feet landward of all perennial and intermittent surface waters. A 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 may 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.
(f) The approval of the stormwater permit shall require an enforceable restriction on property usage that runs with the land, such as recorded deed restrictions or protective covenants, to ensure that future development and redevelopment maintains the site consistent with the approved project plans. (Ord. of 9/3/13)