(A) Project density is used for determining stormwater requirements. The project area used for nutrient calculation and stormwater requirements includes the site area less any existing built-upon area (BUA). The project density is the amount of built-upon area subject to this chapter at project completion divided by the project area. Project density shall be calculated according to 15A NCAC 2H.1003(1) and as indicated in the Design Manual.
(B) A project is categorized as either high density or low density based on the percent BUA, and the density treatment threshold varies depending upon the project's location and proximity to SA waters, which are classified as tidal, salt waters with designated use of shellfishing (15A NCAC 02B.0221). SA waters are more sensitive and are subject to higher standards.
Receiving Water Classification | Low Density Projects | High Density Projects | Design Storm | Special Provisions |
SA - tidal salt waters * SA - HQW SA - ORW | < 12% BUA | > 12% BUA | 1-year, 24-hour storm | Maximum 25% BUA within 575 ft of SA-ORW waters |
Other Coastal County Waters | < 24% BUA | > 24% BUA | 1.5 inch storm | None |
* Per State of North Carolina Surface Water Classifications, all SA tidal salt waters are also high quality waters (HQW) by definition. A subset of SA waters are classified as outstanding resource waters (ORW).
(C) The city is subject to the Coastal Counties Rule, as set forth in 15A NCAC 02H.1019. The Coastal Rule applies to projects that meet one of the following criteria:
(1) Nonresidential projects that propose to cumulatively add 10,000 square feet or more of built-upon area; or
(2) Residential projects that are within 1/2 mile of and draining to SA waters, and propose to cumulatively add more than 10,000 square feet of built-upon area, and result in a percentage built-upon area greater than 12% (high-density).
(D) All other projects not meeting the criteria in division (C) will meet the minimum standards described in 15A NCAC 02H.1003.
(Ord. 23-O-07, passed 4-10-2023)