Madison County, AL Environmental Rules: Flood Elevation Requirements (2026)

Article 4, Section B(1) of the Madison County Flood Damage Prevention Ordinance sets the county's freeboard standard: where base flood elevation (BFE) data is available, new construction and substantial improvement to any structure or manufactured home in an A, AE, or AH zone must have the lowest floor, including the basement, elevated no lower than one foot above the base flood elevation, called the design flood elevation. If solid perimeter walls are used to elevate the structure instead of open piers, the walls must include openings sized to let flood waters move through unimpeded, per the standards in Article 4, Section B(3).

Non-residential structures get an alternative under Section B(2): instead of elevating, they may be dry floodproofed to the same one-foot-above-BFE design flood elevation, with walls substantially impermeable to water and structural components able to resist hydrostatic and hydrodynamic loads and buoyancy. Floodproofing must be certified by an Alabama-licensed professional engineer or registered architect against ASCE 24 standards, with the certified elevation kept in the permitting record in perpetuity. A Floodplain Development Permit is required before any such construction begins, administered by the county's Floodplain Administrator.

Manufactured homes must also be elevated and anchored against flotation, collapse, or lateral movement, using methods such as over-the-top or frame ties to ground anchors, in addition to state and local wind-resistance requirements. Where a structure sits in a zone with multiple BFEs, it must meet the standard for the most hazardous zone and highest BFE on the site.