Guilford County, NC Environmental Rules: Stormwater Management (2026)

UDO Sec. 1 (Stormwater Management and Watershed Protection Districts) applies to all unincorporated Guilford County land shown on the county's adopted 'Designated Water Supply Watershed & NPDES Phase II Stormwater Map,' covering both an NPDES overlay and the Water Supply Watershed overlay, which is split into the Watershed Critical Area (WCA) nearest the reservoir intake and the outer General Watershed Area (GWA). In non-watershed NPDES areas, low-density development is capped at 2 dwelling units per acre or 24% built-upon area (BUA); anything denser or more paved must install stormwater control measures.

Inside the GWA, WS-III watersheds (Reidsville/Troublesome Creek, Greensboro/Reedy Fork, Polecat Creek, Sandy Creek) cap BUA at 50%, with a 10/70 option letting up to 10% of a WS-III area develop non-residentially at up to 70% BUA on a first-come, first-served basis tied to building permit issuance. For WS-IV watersheds, Sec. f(1) sets the ceiling at 70% maximum built-upon area, except the Lower Randleman Lake Watershed, held to 50%, reflecting its role as a Greensboro drinking water source. Limited exemptions exist: construction of a single-family home on a legal lot recorded before watershed rules took effect, redevelopment that doesn't increase BUA, and additions under 400 square feet (one-time, post-1994).

None of these exemptions reach the riparian buffer rules protecting the Jordan Lake and Randleman Lake watersheds. Permanent stormwater control facilities must be substantially complete with full design volume before any plat can record.