§ 44-19. Construction standards for nonresidential structures (except coastal high-hazard areas).  


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  • The following standards apply to new and substantially improved commercial, industrial and other nonresidential structures located in areas of special flood hazard, in addition to the requirements in § 44-15B, Subdivision proposals, and § 44-15C, Encroachments, and § 44-16, Construction standards for all structures.
    A. 
    Within Zones A1-A30, AE and AH, and also Zone A if base flood elevation data are available, new construction and substantial improvements of any nonresidential structure, together with attendant utility and sanitary facilities, shall either:
    (1) 
    Have the lowest floor, including basement or cellar, elevated to or above two feet above the base flood elevation; or
    (2) 
    Be floodproofed so that the structure is watertight below two feet above the base flood elevation with walls substantially impermeable to the passage of water. All structural components located below the base flood elevation must be capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy.
    B. 
    Within Zone AO, new construction and substantial improvements of nonresidential structures shall:
    (1) 
    Have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as two feet above the depth number specified in feet on the community's FIRM (at least two feet if no depth number is specified); or
    (2) 
    Together with attendant utility and sanitary facilities, be completely floodproofed to that level to meet the floodproofing standard specified in § 44-16C.
    C. 
    If the structure is to be floodproofed, a licensed professional engineer or architect shall develop and/or review structural design, specifications, and plans for construction. A floodproofing certificate or other certification shall be provided to the local administrator that certifies the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of § 44-19A(2), including the specific elevation (in relation to mean sea level) to which the structure is to be floodproofed.
    D. 
    Within Zones AH and AO, adequate drainage paths are required to guide floodwaters around and away from proposed structures on slopes.
    E. 
    Within Zone A, when no base flood elevation data are available, the lowest floor (including basement) shall be elevated at least three feet above the highest adjacent grade.