Greenville County, SC Stormwater Regulations

Greenville County is a Phase I medium MS4 under NPDES permit SCS230001, shared with Fountain Inn, Mauldin, Simpsonville, and Travelers Rest. The county's Land Development Division enforces the Storm Water Management Ordinance. Owners of ponds and other BMPs must report inspections and maintenance by January 31 each year. County civil penalties reach $7,500 per violation per day, and state penalties reach $10,000 per day.

Primary source: Greenville County Land Development Division

Permit Requirements

Two layers apply. At the state level, SCDES requires coverage under the NPDES Construction General Permit (SCR100000) for any project disturbing one acre or more. At the county level, the Storm Water Management Ordinance requires a land disturbance permit from the County before clearing, stripping, excavating, or grading.

The county thresholds start well below an acre. A single-family home built on its own, outside a larger common plan, and disturbing less than 5,000 square feet is exempt. Disturbance above 5,000 square feet but under one acre needs a simplified stormwater and sediment control plan, which doesn't require a design professional. Once a site disturbs one acre or more, raises peak runoff by more than one cubic foot per second, or adds a storm drain pipe system, the full plan requirements apply.

The ordinance applies in unincorporated Greenville County and in the cities that share the county's permit: Fountain Inn, Mauldin, Simpsonville, and Travelers Rest. The City of Greenville is separate. It issues its own Stormwater Permits through the city Engineering Division under Section 19-7 of the city code, and a city Grading Permit can only be purchased after that permit is issued.

Inspection Obligations

Construction sites follow the inspection rules in the state Construction General Permit, which calls for an inspection at least once every calendar week. The county adds its own staged inspections of stormwater facilities as they're built, plus a final inspection and certified as-built plans before the permit closes.

After construction, the duty shifts to the owner. Responsible parties, which the ordinance defines to include HOAs and property owner associations, must inspect their facilities at the frequency set in the recorded maintenance agreement, the approved plan, or the county design manual. They must send the County an annual report of inspection, maintenance, and repair work by January 31 for the prior calendar year, and keep inspection records for at least five years. Underground systems need at least one inspection and one separate maintenance visit each year.

The County runs its own periodic post-construction compliance inspections and may enter a property at reasonable times to do so. Its guidance for pond owners recommends routine work such as mowing and debris removal at least twice a year, and sediment removal once it exceeds 25% of the original design depth or blocks an inlet or outlet.

Penalty Structure

Enforcement works on two levels. At the state level, SCDES can assess civil penalties up to $10,000 per day per violation under the South Carolina Pollution Control Act (SC Code Section 48-1-330), and up to $1,000 per day under the Stormwater Management and Sediment Reduction Act.

At the county level, the ordinance allows a civil penalty of up to $7,500 per violation, with each day counted as a separate violation. The County can also charge a misdemeanor in magistrate's court. Work that starts without a required plan and permit gets an automatic stop work order, and ignoring a stop work order can lead to impoundment of equipment on the site.

For a pond or BMP that isn't being maintained, the County mails a notice of violation with the required repairs and a deadline. If the owner doesn't act, the County can do the work after 30 days, or on 24 hours' notice where there's an immediate danger to public health or safety. The cost becomes a lien on the property and can be added to the property tax bill.

The Land Development Division's fee schedule (as of July 1, 2025) also lists violation fees: $750 per lot for unauthorized land disturbance, $500 for a second notice of violation on the same offense, and $1,000 for a compliance inspection tied to a stop work order. A notice of violation can be appealed in writing within 30 days.

Key BMPs

The county ordinance lists stormwater measures in order of preference, with green infrastructure first and on-site ponds near the bottom:

• Green infrastructure and low impact development - First preference. Includes bioretention swales and basins, porous pavement, and smaller street, parking, and rooftop footprints, paired with on-site detention for larger storms.
• Overland flow and buffer zones - Facilities that slow runoff and route it through vegetated buffers before it reaches a stream.
• Dry detention basins - Regional basins are preferred over on-site ones. Peak discharge for the 2-year, 10-year, and 25-year storms must stay at pre-development rates, and the 100-year storm must pass safely.
• Wet retention basins - Allowed, but a wet basin can't double as a sediment basin during construction.
• Infiltration practices - Listed for sites where permeable soils are present.
• Stream buffers - A 50-foot undisturbed buffer on each side of streams draining less than 50 acres, and 100 feet where the drainage area is 50 acres or more.

Local Ordinances

The county's Storm Water Management Ordinance sits in Sections 8-51 through 8-143 of the county code and was last revised by Ordinance No. 5716, adopted July 15, 2025. It sets a water quality standard on top of the state rules: sites over one acre must design BMPs to trap 85% of total suspended solids on an annual basis. Designs follow the county's Stormwater Management Design Manual.

Some areas carry extra requirements. Sites in the Gilder Creek watershed must also control the 50-year storm. Sites inside Mauldin and Simpsonville city limits must hold the 100-year peak discharge to pre-development rates. Development draining to a waterbody that SCDES lists as impaired, or that has a TMDL, may need a Special Pollution Abatement Permit.

Greenville County funds its program with a stormwater utility fee that arrives with the property tax notice each October. Residential parcels are billed in two categories by heated first-floor area, and non-residential parcels are billed on impervious surface. Owners have 30 days from delivery of the tax bill to appeal the amount.

The City of Greenville charges its own stormwater utility fee. For 2026 to 2027, the city lists $47.69 a year for developed homes under 1,640 square feet and $83.75 for larger homes. Commercial and industrial properties pay $83.75 per equivalent residential unit, which the city sets at 2,389 square feet of impervious area.