(A) Low-density projects shall comply with each of the following standards.
(1) Transporting storm water runoff. Storm water runoff from the development shall be transported from the development by vegetated conveyances to the maximum extent practicable.
(2) Built-upon area. All built-upon area shall be at a minimum of 30 feet landward of all perennial and intermittent surface waters. A perennial or intermittent surface water shall be 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 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.
(3) Restriction on property. The approval of the storm water permit shall require an enforceable restriction on property usage that runs with the land, such as a recorded deed restriction or protective covenants, to ensure that future development and redevelopment maintains the site consistent with the approved project plans.
(B) High-density projects shall implement storm water control measures that comply with each of the following standards.
(1) Storm water volume. The measures shall control and treat the difference in storm water runoff volume leaving the project site between the pre- and post-development conditions for, at a minimum, the one-year, 24-hour storm. Runoff volume drawdown time shall be a minimum of 24 hours, but not more than 120 hours.
(2) Total suspended solids. All structural storm water treatment systems used to meet the requirements of the program shall be designed to have a minimum of 85% average annual removal for total suspended solids (TSS).
(3) Design Manual. General engineering design criteria for all projects shall be in accordance with 15A NCAC 2H .1008(c), as explained in the design manual.
(4) Built-upon area. All built-upon area shall be at a minimum of 30 feet landward of all perennial and 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 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.
(5) Restriction on property. The approval of the storm water 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. passed 1-15-2008)