South Carolina Stormwater Regulations
South Carolina stormwater permits are administered by SCDES (formerly SCDHEC), with additional coastal overlay requirements from OCRM in the 8 coastal counties. Property owners must maintain BMPs under recorded maintenance agreements, and municipalities enforce compliance through MS4 programs. The state's CGP (SCR100000) was reissued in 2026 and runs through March 29, 2031.
State Regulatory Overview
The South Carolina Department of Environmental Services (SCDES) serves as the primary authority for stormwater regulation statewide. SCDES took over these responsibilities from SCDHEC following the agency restructuring. The department administers all NPDES stormwater permits, reviews Stormwater Pollution Prevention Plans (SWPPPs), and conducts enforcement actions for non-compliance.
In the 8 coastal counties, the Office of Ocean and Coastal Resource Management (OCRM) adds a second layer of permitting. OCRM regulates development within critical areas along SC's coastline and imposes additional stormwater treatment, setback, and density requirements. Any project within the 8 coastal counties that falls within OCRM's jurisdiction needs both SCDES stormwater permits and OCRM critical area permits.
South Carolina's stormwater framework is built on the federal Clean Water Act's NPDES program, supplemented by state-specific laws including the SC Pollution Control Act, the Stormwater Management and Sediment Reduction Act, and the Coastal Zone Management Act.
County Coverage
This hub covers 11 South Carolina counties with county-level data: the 8 coastal counties and 3 inland counties, Greenville, Lexington, and Richland. Each county has its own local stormwater ordinances that implement state permit requirements. The Penalties column shows the SC Pollution Control Act ceiling, plus a county figure where the county ordinance sets one.
| County | MS4 Status | Key City | Penalties |
|---|---|---|---|
| Beaufort | Phase II MS4 | Hilton Head, Beaufort, Bluffton | State: up to $10,000/day |
| Berkeley | Phase II MS4 | Goose Creek, Moncks Corner | State: up to $10,000/day |
| Charleston | Phase II MS4 | Charleston, Mt. Pleasant, Summerville | State: up to $10,000/day |
| Colleton | Not MS4 regulated | Walterboro | State: up to $10,000/day |
| Dorchester | Phase II MS4 | Summerville, North Charleston | State: up to $10,000/day |
| Georgetown | Phase II MS4 (partial) | Georgetown, Pawleys Island | State: up to $10,000/day |
| Greenville | Phase I Medium MS4 | Greenville, Mauldin, Simpsonville | State: up to $10,000/day; County: up to $7,500/day |
| Horry | Phase II MS4 | Myrtle Beach, Conway | State: up to $10,000/day |
| Jasper | Not MS4 regulated | Hardeeville | State: up to $10,000/day |
| Lexington | Phase II MS4 | Lexington, West Columbia, Cayce | State: up to $10,000/day |
| Richland | Phase I Medium MS4 | Columbia, Forest Acres | State: up to $10,000/day; County: up to $500/day |
Key State Laws
- SC Pollution Control Act (S.C. Code 48-1) - The primary environmental enforcement law. Authorizes SCDES to issue permits, conduct inspections, and assess penalties up to $10,000 per day for violations including unpermitted discharges and failure to maintain stormwater controls.
- Stormwater Management and Sediment Reduction Act (S.C. Code 48-14) - Requires land-disturbing activities of one acre or more to obtain a stormwater permit and implement erosion and sediment controls. Mandates post-construction BMP maintenance agreements.
- SC Coastal Zone Management Act (S.C. Code 48-39) - Establishes OCRM's authority over development in the coastal zone. Requires critical area permits for projects within specified distances of tidal waters, beaches, and primary sand dunes.
- SC Water Quality Standards (R.61-68) - Defines water quality classifications and standards that stormwater discharges must meet. Includes anti-degradation provisions for Outstanding National Resource Waters and high-quality waters.
Permit Types
Construction General Permit (CGP) - SCR100000
The SC CGP covers all land-disturbing activities of one acre or more. Operators must file a Notice of Intent (NOI), develop a SWPPP, implement erosion and sediment controls, and maintain post-construction BMPs. SCDES reissued the permit on February 27, 2026. The current permit took effect March 30, 2026, and expires March 29, 2031.
MS4 Permits
SC's MS4 permits require municipalities to implement stormwater management programs covering six minimum control measures: public education, public involvement, illicit discharge detection, construction site runoff control, post-construction management, and pollution prevention. SCDES lists one large MS4 (SCDOT) and three medium MS4s, the City of Columbia, Greenville County, and Richland County, each under its own Phase I permit. Smaller urbanized areas, including Lexington County and most coastal communities, hold Phase II permits.
Industrial Stormwater Permits
Industrial facilities with outdoor operations exposed to rainfall must obtain coverage under SC's Multi-Sector General Permit or an individual stormwater permit. These permits require stormwater sampling, pollution prevention plans, and regular monitoring reports to SCDES.
Frequently Asked Questions
Who regulates stormwater in South Carolina?
The South Carolina Department of Environmental Services (SCDES, formerly SCDHEC) is the primary stormwater regulatory authority. SCDES administers NPDES stormwater permits, including the Construction General Permit (CGP), MS4 permits, and industrial stormwater permits. In the 8 coastal counties, the Office of Ocean and Coastal Resource Management (OCRM) adds an additional permitting layer for projects within the critical area.
What is the SC Construction General Permit (CGP)?
The SC CGP, permit number SCR100000, covers land-disturbing activities of one acre or more. It requires a Stormwater Pollution Prevention Plan (SWPPP), erosion and sediment controls during construction, and post-construction BMP maintenance. SCDES reissued the permit on February 27, 2026. The current permit took effect March 30, 2026, and expires March 29, 2031.
What are OCRM coastal stormwater requirements?
OCRM regulates development within SC's coastal critical areas, which extend from the mean high-water mark to 40 feet landward of the crest of the primary oceanfront sand dune. Projects in these areas need both SCDES stormwater permits and OCRM critical area permits. OCRM imposes additional setback, density, and stormwater treatment requirements in Beaufort, Berkeley, Charleston, Colleton, Dorchester, Georgetown, Horry, and Jasper counties. Inland counties such as Greenville, Lexington, and Richland are outside OCRM's coastal permitting area.
What penalties exist for stormwater violations in SC?
SCDES can issue civil penalties up to $10,000 per day per violation under the SC Pollution Control Act (S.C. Code 48-1-330) and up to $1,000 per day under the Stormwater Management and Sediment Reduction Act (S.C. Code 48-14-140). Counties and municipalities may impose additional local fines through their stormwater ordinances. Common violations include failing to maintain BMPs, operating without a permit, and discharging sediment or pollutants to waterways. Repeat violations often result in consent orders with specific corrective action timelines.
Do SC property owners need to maintain stormwater BMPs?
Yes. Most developments approved after the early 2000s have recorded stormwater maintenance agreements that legally bind the property owner, typically the HOA or commercial entity, to maintain all on-site BMPs to their original design specifications. Municipalities enforce these requirements through annual inspections under their MS4 permits.
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