Construction Guide · Charleston Metro, SC

Stormwater Management Requirements for New Construction in Charleston County

Charleston County's stormwater rules blend state permitting, county ordinances, and city-specific design manuals — and getting the sequence wrong can stall a project for months. Here's how the pieces fit together, and where to verify specifics first.

A New Agency, Familiar Framework

South Carolina dissolved DHEC on July 1, 2024, splitting its duties between the new SC Department of Public Health and the SC Department of Environmental Services, which now oversees stormwater and NPDES permitting. Statewide, Construction General Permit coverage kicks in at one acre disturbed — a floor, not a ceiling, for local requirements.

Jurisdiction Is the Real Variable

Charleston County's own permitting manual reportedly reaches further than the state threshold, suggesting permits apply to most construction — including single-family homes — regardless of acreage; that detail is worth confirming before you rely on it. The county is also just one jurisdiction among several — Charleston, North Charleston, Mount Pleasant, Summerville, and the barrier island towns — each layering its own design standards on top of state rules, so verify which manual actually governs your parcel.

Obligations Outlive the Certificate of Occupancy

Stormwater duties in Charleston County typically extend well past construction. Installed BMPs are often tied to a recorded operating permit or maintenance agreement obligating the owner to ongoing upkeep, monitored by the county's Public Works Department — a long-term obligation worth weighing during design, not after closing.

Wondering how these requirements could affect your next Charleston project? Contact Chris Eller directly.