(A) New construction and substantial improvements of any commercial, industrial or other non-residential structure, together with attendant utility and sanitary facilities, shall either: have the lowest floor, including basement or cellar, elevated to or above the base flood elevation; or be floodproofed so that the structure is watertight below the base flood level with walls substantially impermeable to the passage of water.
(B) All structural components located below the base flood level must be capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy.
(1) If the structure is to be elevated, fully enclosed areas below the base flood elevation shall be designed to automatically (without human intervention) allow for the entry and exit of flood waters for the purpose of equalizing hydrostatic flood forces on exterior walls. Designs for meeting this requirement must either be certified by a licensed professional engineer or a licensed architect or meet the following criteria:
(a) A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding;
(b) The bottom of all openings shall be no higher than one foot above the lowest adjacent finished grade; and
(c) Openings may be equipped with louvers, valves, screens or other coverings or devices provided they permit the automatic entry and exit of flood waters.
(2) If the structure is to be floodproofed:
(a) A licensed professional engineer or architect shall develop and/or review structural design, specifications and plans for the construction, and shall certify that the design and methods of construction are in accordance with accepted standards of practice to make the structure watertight with walls substantially impermeable to the passage of water, with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
(b) A licensed professional engineer or licensed land surveyor shall certify the specific elevation (in relation to mean sea level) to which the structure is floodproofed.
(3) The Local Administrator shall maintain on record a copy of all the certificates noted in this section.
(Ord. 1-1987, passed 4-13-1987)