Floodproofing rules for buildings in flood zones

(a) General. Building permit applications for structures that require floodproofing under Chapter 21A and this article shall be accompanied by a statement of a registered professional engineer or architect that to the best of such person’s knowledge, information, and belief, the floodproofing methods are adequate to resist the flood depths, pressures, velocities, impact, and uplift forces, and other factors associated with the flood, including flood waters due to tsunamis in coastal high hazard areas. (b) Floodproofing of buildings above base flood elevation. All buildings and structures that are required to be elevated above the base flood elevation shall be floodproofed by building on natural terrain above the base flood elevation on natural undisturbed ground or by building on stilts or by building on fill (unless fill is specifically prohibited by Chapter 21A , in the particular flood hazard area) or by other approved methods. (c) Waterproofing of buildings below base flood elevation. Any building or portion thereof, not used for human habitation, and that is permitted to be below the base flood elevation shall either have the space below the base flood elevation free of obstructions or shall be designed and constructed so that below the base flood elevation, 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 due to the base flood. Compliance with the requirements of ASCE 24 shall be in compliance with this section. Within coastal high hazard areas, however, any usable enclosed space below the base flood elevation shall be constructed with breakaway walls intended to collapse under stress without jeopardizing the structural support of the building. Areas enclosed by such breakaway walls shall not be used for human habitation. ; Sec. 16-5.3 R.O. 1978 (1987 Supp. to 1983 Ed.))