In Charlotte, permeable resin-bound surfacing counts for stormwater only as part of an engineered permeable pavement system that meets Chapter 4.5 of the Charlotte-Mecklenburg SCM Design Manual, which adopts North Carolina's permeable pavement criteria with local changes. If Storm Water Services accepts the surface and the section is designed to infiltrate, it can be treated as pervious when the City tallies built-upon area, which matters on infill sites sitting close to a density threshold.
Over an existing slab it is a different product. Rain passes through the resin-bound layer and then runs off the concrete or asphalt below, so it should not be presented as a stormwater control or used in a fee credit application. On Charlotte's clay subsoils, the base design usually decides whether a project earns any credit at all.
The PCSO, the SCM manual and Charlotte's built-upon area credit
Charlotte-Mecklenburg Storm Water Services administers the Post-Construction Stormwater Ordinances, and the City applies them to redevelopment as well as new development. Requirements combine stormwater control measures, stream and lake buffers of 30 to 200 feet, and open space of 10 to 25 percent depending on built-upon area (BUA), with a mitigation fee option for qualifying sites. Inside the City, the rules are Article 25 of the Unified Development Ordinance.
The July 2025 SCM Design Manual accepts NCDEQ Chapter C-5 with exceptions. Pavement designed to infiltrate the 1-inch, 6-hour design storm is viewed as 100 percent pervious for its own footprint, though not for areas draining onto it, and no BUA credit may be used to exceed maximum BUA limits in water supply watersheds. The manual recommends a surface slope of 6 percent or less, requires an observation well at every low point and at least one per 10,000 square feet, and drops the state exemption for screened rooftop runoff. C-5 itself sets a surface infiltration rate of at least 50 inches per hour and asks anyone proposing a surface other than pavers, pervious concrete or porous asphalt to prove long-term performance.
State law has also moved. A July 7, 2026 Storm Water Services memo says that under Session Laws 2026-32 and 2026-39, BUA density is calculated from July 1, 2026 with existing BUA set aside. For Article 25 projects the memo ties existing BUA to the 2023 start of the UDO rules, listing both June 1 and July 1, 2023, so confirm the baseline date with Storm Water Services. Redevelopment math may now look different.
Clay subsoils and lake watersheds: questions for the base design
Much of Mecklenburg County sits on Piedmont clay over weathered rock, and infiltration can change sharply across a single parcel. C-5 calls for site-specific soil testing, at least two feet between the subgrade and the seasonal high water table for infiltrating systems, a subgrade at 2 percent slope or less, and washed stone. Where soils cannot drain the design volume within 72 hours, the engineer should switch to an underdrained detention design, which still treats runoff but does not earn the pervious BUA credit.
Location matters as much as soil. Parts of the county fall in the Mountain Island Lake and Lake Wylie watershed overlays, where BUA caps apply and the manual refuses credit that would push past them. C-5 treats active fueling, fleet and industrial areas as hotspots and presumes contaminated soil on sites with that history until an investigation shows otherwise. Stormwater cannot be infiltrated into contaminated soil, so a lined detention design may be the option there, and fill on older rail and industrial land should be tested before anyone infiltrates through it.
Where it fits in Charlotte
- South End, NoDa and Plaza Midwood infill, where plazas, courtyards and parking stalls in permeable pavement can help a redevelopment site's BUA calculation.
- Single-family lots under an acre in older neighborhoods such as Dilworth or Myers Park, adding a patio or parking pad without crossing a BUA threshold.
- Church, school and office parking with permeable stalls and conventional drive aisles, within C-5's 1:1 limit on run-on from other hard surfaces.
- Multifamily and HOA common areas looking for added on-site control before applying for a fee credit.
Approval and supply in Charlotte
Storm Water Services reviews permeable pavement as an SCM during land development review. For an individual residential lot under one acre in the City, the manual lets designers use NRCS soil survey values for preliminary design, then requires a signed and sealed report showing the system works as designed and a recorded plat note before the certificate of occupancy hold is released. That note makes the owner responsible for maintenance, tells the owner to avoid sealing or repaving with impervious material, and requires City approval for any changes to the pavement.
Fee credits are a separate application. Storm Water Services lists a Stormwater Control Measure Credit for engineered features alongside pond, Catawba River and county line credits, filed through Accela Citizen Access. None of it is automatic for a resin-bound surface.
Resin Rock does not install. We supply the binder, stone blends, trims and Rock Crete permeable sub-base, publish technical data sheets for submittals, and train and approve installers. Homeowners refinishing an existing slab can see our Charlotte concrete resurfacing page; for a permeable build, request an approved installer.
Before you specify permeable resin-bound in Charlotte
- Confirm the parcel's watershed district and any water supply overlay.
- Run the BUA density calculation under the July 2026 existing-BUA method.
- Test soils at subgrade depth and locate the seasonal high water table.
- Size the reservoir to infiltrate the 1-inch, 6-hour storm if you want the pervious credit.
- Show observation wells at each low point and at least one per 10,000 square feet.
- Draft the plat note and maintenance commitments before the certificate of occupancy stage.
Common questions about permeable resin-bound in Charlotte
Does permeable resin-bound count as impervious on my Charlotte storm water bill?
Storm Water Services bills from mapped impervious area: detached homes fall into four tiers from $10.32 to $35.48 a month, and other properties pay $242.30 per impervious acre. Whether an engineered permeable section is billed differently is a question for Storm Water Services. A resin-bound overlay on an existing driveway stays impervious, because the slab beneath still sheds the water.
Can a Charlotte homeowner use the pervious BUA credit?
Yes, the SCM manual has a path for individual residential lots under one acre inside the City. NRCS soil data can be used for preliminary design, but the finished system needs a signed and sealed report showing it infiltrates as designed and a recorded plat note committing the owner to maintenance. In practice, most homeowners will need an engineer to carry it.
Is resin-bound an accepted permeable surface in Charlotte?
It is not one of the surfaces the state manual names. Chapter C-5, which Charlotte adopts, lets designers propose other surfaces if they show long-term hydraulic and structural performance and a surface infiltration rate of at least 50 inches per hour. Your engineer should raise it with Storm Water Services early, with data sheets and the base design in hand.
Official sources for Charlotte
- Charlotte-Mecklenburg SCM Design Manual (Chapter 4.5, Permeable Pavement)
- City of Charlotte: Post-Construction Stormwater Ordinances
- City of Charlotte: Storm Water Fees and Credits
Local rules change. We last checked these sources in October 2026. Confirm current requirements with the reviewing agency before you design, and treat this page as a starting point, not engineering or permitting advice.