Where floodproofing is to be used for a particular structure in accordance with this Division, a registered professional engineer or architect shall certify that the floodproofing methods are adequate to withstand flood depths, pressures, velocities, impact and uplift forces and other factors associated with the base flood, and a record of such certificates indicating the specific elevation in relation to mean sea level) to which such structures are floodproofed shall be maintained with the Planning Director.