Alexandria, VA Environmental Rules: Flood Zones (2026)

Section 6-301 adopts the floodplain regulations under Va. 2-2280 to prevent loss of life, property damage, and disruption from flooding. Section 6-302 applies the rules to every SFHA parcel shown on FEMA's Flood Insurance Rate Map for the City dated January 11, 2024. Section 6-304 splits the mapped floodplain into three districts: the Floodway District (AE zone), where "no encroachments, including fill, new construction, substantial improvements, or other development shall be permitted" unless a licensed engineer demonstrates through hydrologic and hydraulic analysis that the project will cause zero rise in the base flood elevation; the AE/AH district, where uses are allowed once elevation and floodproofing standards are met; and the approximate A Zone, where the applicant must establish the base flood elevation using accepted engineering methods before building.

Manufactured and mobile homes are flatly prohibited within the Floodway District under Section 6-304(A)(1)(b). S. Army Corps of Engineers, the Virginia Department of Environmental Quality, and the Virginia Marine Resources Commission is required before altering or relocating any channel or watercourse under Section 6-306. Buildings that predate the January 11, 2024 FEMA remapping and already held a valid permit are grandfathered until they undergo substantial improvement, at which point Section 6-300's current standards apply in full.