A. In flood hazard Zones A and AE, a new nonresidential structure, or the substantial improvement of an existing nonresidential structure, shall be constructed according to one of the two following requirements:
1. The lowest floor shall be constructed at an elevation to or above the regulatory flood elevation; or
2. The lowest floor may be constructed at an elevation lower than the regulatory flood elevation, but floodproofing shall be provided for the structure to an elevation which is to or above the regulatory flood elevation.
B. In flood hazard Zone AO, a new nonresidential structure, or the substantial improvement of an existing nonresidential structure, shall be constructed according to one of the following requirements:
1. The lowest floor shall be constructed at an elevation at least one foot above the elevation determined by finding the elevation of the highest ground adjacent to where the structure will be located, and adding to that elevation the depth number specified on the FIRM for that AO Zone; or
2. The lowest floor may be constructed below the minimum lowest floor elevation specified in subdivision B.1 above, but floodproofing shall be provided for the structure to an elevation one foot above the depth number specified on the FIRM for that AO Zone.
C. Nonresidential construction, whether new or substantially improved, shall either be elevated in conformance with subsections A and B of this section, or together with attendant utility and sanitary facilities, shall:
1. Be floodproofed so that below the regulatory flood elevation the structure is watertight, with walls substantially impermeable to the passage of water;
2. Have structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy; and
D. Be certified by a registered, professional surveyor, engineer or architect that the standards of this subsection are satisfied. Upon completion of the structure, certification by a registered, professional engineer or surveyor that the elevation requirements of the lowest floor, including basement, of this section have been satisfied, shall be provided to the floodplain administrator for verification. Where floodproofing has been used to satisfy the requirements of this section, written certification by a registered, professional engineer or architect shall be provided to the floodplain administer, upon completion of the structure, that verifies that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in FEMA Technical Bulletin 3, titled “Nonresidential Floodproofing: Requirements and Certification.”
(Ord. 1397.15.22 § 1 (part), 2019; prior code § 17-4-1(H) (part))