Pontiac, MI Environmental Rules: Flood Elevation Requirements (2026)

Once base flood elevation data exists for a site, whether from the FEMA flood insurance study referenced in § 66-29 or from other data the administrator gathers under § 66-42(b), City Code § 66-57 sets the construction standard. New construction and any substantial improvement of a residential structure must have its lowest floor, including a basement, elevated to or above the base flood elevation; there is no floodproofing alternative for residential buildings. Nonresidential structures, commercial, industrial or otherwise, may either meet that same elevation standard or floodproof instead: the building and its utility and sanitary facilities must be watertight below the base flood level with walls substantially impermeable to water, built with structural components able to resist hydrostatic and hydrodynamic loads and the effects of buoyancy, and certified by a registered professional engineer or architect that those standards are met, with the certification filed with the administrator under § 66-42(a)(4)b.

Mobile homes get a parallel elevation rule under § 66-57(3): stands or lots must be elevated on compacted fill or pilings so the lowest floor sits at or above the base flood level, with adequate drainage and hauler access, and homes placed on pilings need additional bracing. The administrator of the building and safety engineering division verifies and records the actual elevation of the lowest floor of every new or substantially improved structure, in relation to mean sea level, as part of enforcing § 66-57.