Stormwater Management Through Landscaping in South Carolina
South Carolina's combination of intense summer rainfall, flat coastal plains, and rapidly expanding suburban development makes stormwater runoff one of the most consequential land-management challenges in the state. This page covers how landscape design and plant selection function as engineered tools for capturing, slowing, and filtering runoff — and how those tools intersect with South Carolina regulatory frameworks. The material addresses residential, commercial, and municipal contexts, drawing on guidance from the South Carolina Department of Health and Environmental Control (SCDHEC) and related federal programs.
Definition and scope
Stormwater management through landscaping refers to the deliberate design and installation of vegetated or soil-based systems that intercept precipitation before it becomes concentrated surface flow. Unlike structural solutions such as concrete detention basins, landscape-based approaches rely on biological and physical processes — root infiltration, evapotranspiration, microbial soil activity, and canopy interception — to reduce runoff volume and improve water quality.
In South Carolina, stormwater management is governed primarily by SCDHEC under the authority of the South Carolina Stormwater Management and Sediment Reduction Act (S.C. Code Ann. § 48-14) and the federal National Pollutant Discharge Elimination System (NPDES) permit program administered by the U.S. Environmental Protection Agency. Land-disturbing activities affecting 1 acre or more require a Land Disturbance Permit from SCDHEC (SCDHEC Construction Stormwater Program). Landscaping that falls below this threshold is typically self-regulated at the property level, though HOA covenants and local municipal ordinances may impose additional requirements (see South Carolina Landscaping Regulations & HOA).
Federal water funding context: As of October 4, 2019, federal law permits States to transfer certain funds from a State's clean water revolving fund to its drinking water revolving fund in certain circumstances. This transfer authority may affect the allocation of State revolving fund resources available to municipalities for water quality infrastructure, which can intersect with stormwater and landscaping capital programs at the local level.
Scope and coverage limitations: This page addresses stormwater management practices within South Carolina's borders and under SCDHEC and municipal jurisdiction. It does not address stormwater regulations in adjacent states (North Carolina, Georgia) or federal wetland permitting under Section 404 of the Clean Water Act beyond general reference. Agricultural operations subject to separate SCDHEC agricultural exemptions are also outside this page's scope.
How it works
Landscape-based stormwater management operates through four primary mechanisms:
- Infiltration — Vegetated soil allows water to percolate downward, reducing surface flow. A healthy turfgrass system can infiltrate 0.5 to 1.0 inch of rainfall per hour under good soil conditions (Penn State Extension, Turfgrass Infiltration). South Carolina's piedmont clay soils present infiltration challenges addressed in detail at South Carolina Landscaping Soil Types.
- Evapotranspiration (ET) — Plants return intercepted water to the atmosphere through leaf surfaces and root-driven soil drying, reducing the net volume that reaches drainage systems.
- Filtration and phytoremediation — Root zones and associated microbial communities remove nutrients (especially nitrogen and phosphorus), sediment, and heavy metals from water moving through the soil profile. Native riparian plants such as Cephalanthus occidentalis (buttonbush) and Spartina alterniflora (smooth cordgrass) are particularly effective in coastal South Carolina settings.
- Flow velocity reduction — Dense ground cover, mulch, and strategically placed berms dissipate kinetic energy, reducing erosion and allowing sediment to settle before water enters streams or storm drains.
These mechanisms are the functional core of Low Impact Development (LID), a design philosophy formally endorsed by the EPA and incorporated into SCDHEC's South Carolina Stormwater Design Manual. For a broader orientation to how these principles fit within professional landscape services, the conceptual overview of South Carolina landscaping services provides useful context.
Common scenarios
Bioretention cells (rain gardens): Shallow, planted depressions sized to capture the first 1 inch of runoff from an impervious catchment area. They are the most widely deployed LID feature in South Carolina residential subdivisions. A standard rain garden serving a 1,000 square foot roof area is typically sized at 100–300 square feet, depending on soil permeability. Native plants suited to periodic inundation — such as Lobelia cardinalis and Iris virginica — are preferred (see South Carolina Native Plants Landscaping).
Vegetated swales: Grassed or planted channels that replace concrete-lined storm drains. They slow flow velocity, promote infiltration, and filter pollutants. Coastal and low-country properties benefit substantially from swales planted with salt-tolerant species — a subject covered at South Carolina Coastal Landscaping Services.
Riparian buffers: Strips of vegetation maintained along stream banks and drainage easements. SCDHEC's Riparian Buffer Incentive Program encourages buffers of at least 35 feet on each side of a stream channel. Buffers at this width have been shown to remove up to 80% of sediment and 50% of nitrogen from overland flow (USDA Natural Resources Conservation Service, Conservation Practice Standard 393).
Green roofs and planter walls: More common in commercial contexts, these systems hold 1–4 inches of growing media that temporarily stores and evapotranspirates rainfall. They are detailed further under South Carolina Commercial Landscaping Services.
Permeable hardscape integration: Permeable pavers, gravel borders, and decomposed granite paths reduce total impervious area. When combined with planted beds, they can reduce runoff from a residential lot by 30–50% compared to conventional paving (EPA, Managing Wet Weather with Green Infrastructure).
Municipal funding considerations: Effective October 4, 2019, States may transfer certain funds from their clean water revolving fund to their drinking water revolving fund under specified circumstances. Municipalities evaluating landscape-based stormwater projects funded through State revolving fund mechanisms should confirm with their State revolving fund administrator how this transfer authority may affect available clean water fund balances for stormwater-eligible projects.
Decision boundaries
Passive landscape measures vs. engineered detention: Bioretention and swales are appropriate for lots where runoff volume from a 1-inch storm event can be managed within the site's available pervious area. Where a site generates more than 0.5 acre-feet of runoff from a 2-year storm event, engineered detention or retention ponds are typically required under SCDHEC permits. The South Carolina Erosion Control Landscaping page addresses transitional scenarios where both approaches overlap.
Native vs. non-native plant selection: Native species generally require less supplemental irrigation, establish deeper root systems (often 12–24 inches vs. 4–8 inches for common turf cultivars), and tolerate South Carolina's rainfall variability more effectively. The trade-off is that non-native turf species such as Bermudagrass (Cynodon dactylon) offer superior surface stability in high-traffic areas. For projects where drought tolerance is also a constraint, South Carolina Drought-Tolerant Landscaping outlines compatible species choices.
Residential vs. commercial compliance thresholds: Residential projects below 1 disturbed acre are not subject to NPDES Construction General Permit requirements but remain subject to local municipal stormwater ordinances in jurisdictions such as Charleston, Columbia, and Greenville. Commercial and multi-family projects above the 1-acre threshold must submit a Stormwater Pollution Prevention Plan (SWPPP) to SCDHEC before breaking ground.
Maintenance obligations: Landscape-based stormwater features carry long-term maintenance obligations that structural systems do not. A bioretention cell that loses vegetation cover or becomes clogged with sediment can reverse from an infiltration asset to a standing-water liability. Maintenance schedules aligned with South Carolina's seasonal rainfall pattern are outlined at South Carolina Landscape Maintenance Schedules. Projects seeking a comprehensive entry point to stormwater landscaping should also review the South Carolina Landscaping homepage for regulatory and service context.
References
- South Carolina Stormwater Management and Sediment Reduction Act — S.C. Code Ann. § 48-14
- SCDHEC Construction Stormwater Program
- SCDHEC South Carolina Stormwater Design Manual
- U.S. EPA — Managing Wet Weather with Green Infrastructure
- U.S. EPA — National Pollutant Discharge Elimination System (NPDES)
- USDA NRCS Conservation Practice Standard 393 — Filter Strip
- Penn State Extension — Turfgrass Water Use and Infiltration
- Federal law (effective October 4, 2019) permitting States to transfer certain funds from the clean water revolving fund to the drinking water revolving fund in certain circumstances