In all areas of special flood hazard where base flood elevation data has been provided as set forth in subsection 12-3-3B of this title, the following standards are required:
A. Residential: New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above base flood elevation.
B. Nonresidential: New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to the level of the base flood elevation, or, together with attendant utility and sanitary facilities, shall be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water; have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certifications shall be provided to the official as set forth in subsection 12-3-3C of this title. (1995 Code § 27-4-6)