(A) On the basis of the most recent available base flood elevation data, the following standards shall apply in the flood hazard area zone:
(1) All new construction and substantial improvements of residential structures shall have the lowest floor, including basement, elevated to or above the base flood level; and
(2) All new construction and substantial improvements of nonresidential structures shall have either:
(a) The lowest floor, including basement, elevated to or above the base flood level; or
(b) Be constructed so that below base flood level, together with attendant utility and sanitary facilities, the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. A registered professional engineer or architect shall certify that the standards of this subsection are satisfied, and that the floodproofing methods employed are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces, and other factors associated with a base flood in the location of the structure.
(B) The most recent base flood elevation data received from the Federal Insurance Administration shall take precedence over data from other sources.