Establishment of Stormwater Management Permit
A Stormwater Management Permit (see §42-357 (Stormwater Management Permit)) shall not be
required for development and redevelopment that: (1) cumulatively disturbs less than one (1) acre and
is not part of a larger common plan of development or sale is exempt from the provisions of this
Subpart B; (2) occurs within a designated water supply watershed; or (3) occurs within a larger
development for which a stormwater management permit has been issued, provided the property owner
complies with the requirements of the overall projects stormwater management permit. A Stormwater
Management Permit (see §42-357 (Stormwater Management Permit)) shall be required in conformance
with the provisions of this Chapter for:
Development and redevelopment that cumulatively disturbs more than one (1) acre and is not part
of a larger common plan of development or sale;
Development and redevelopment that disturb less than one (1) acre where such activities are part
of a larger common plan of development or sale, even though multiple, separate or distinct
activities take place at different times on different schedules; or
Any activity not exempt from permit requirements of Section 404 of the Federal Clean Water Act
as specified in 40 CFR 232 (primarily, ongoing agriculture and forestry activities).
Where a Stormwater Management Permit is required for a high-density project as noted in §42-240.5
(Standards for High-Density Projects), stormwater control measures shall be implemented that comply
with each of the following standards:
The measures shall control and treat stormwater runoff from the first inch of rain over a 24-hour
period. Runoff volume drawdown time shall be a minimum of 48 hours, but not more than 120
All structural stormwater treatment systems used to meet these requirements shall be designed to
have a minimum of 85% average annual removal for Total Suspended Solids (TSS).
General engineering design criteria for all projects shall be in accordance with 15A NCAC 2H
.1008(c), as explained in the Stormwater BMP Manual.
No development or redevelopment shall occur except in compliance with the provisions of this Subpart B or unless
exempted. No development for which a permit is required pursuant to this Subpart B shall occur except in
compliance with the provisions, conditions, and limitations of the permit.
The approval of the Stormwater Management 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