Fairfax County, VA Environmental Rules: Stormwater Management (2026)

Stormwater management in Fairfax County is governed by the Virginia Stormwater Management Act (VA Code §62.1-44.15:24 et seq.), implemented through the Virginia Stormwater Management Program (VSMP) regulations, and administered locally by Fairfax County Land Development Services. Fairfax County has adopted a more restrictive land-disturbance threshold than the state minimum — activities disturbing 2,500 square feet or more trigger the county stormwater requirements (versus 1 acre at state level). Projects meeting the threshold must submit a Stormwater Management Plan (SWMP) addressing both water quality (pollutant removal to meet Chesapeake Bay TMDL goals) and water quantity (peak discharge control). Best Management Practices (BMPs) may include bioretention facilities, dry and wet ponds, permeable pavement, infiltration trenches, green roofs, and vegetated swales. The Virginia Runoff Reduction Method is used to calculate required phosphorus load reductions. Erosion and Sediment Control (E&SC) plans are also required under the Virginia Erosion and Sediment Control Law — silt fencing, sediment traps, stabilized construction entrances, and seeding of disturbed areas are standard requirements. A preconstruction meeting and inspections at key stages are mandatory. Long-term BMP maintenance agreements are recorded against the property, obligating all future owners. Within Chesapeake Bay Preservation Areas — which cover much of Fairfax County along Potomac tributaries — the Chesapeake Bay Preservation Ordinance adds Resource Protection Area (RPA) buffers and Resource Management Area (RMA) performance standards. Violations of stormwater requirements are subject to civil penalties up to $32,500 per day under Virginia law.