In all identified flood hazard areas where base flood elevations have been provided in the FIS or generated by a certified professional in accordance with § 151.06(C), the following provisions shall apply.
(A) Residential construction. New construction or substantial improvement of any residential structure (including manufactured homes) in Zones AE and A (as defined on the FIRM) with detailed base flood elevations shall have the lowest floor, including basement, elevated to or above the base flood level plus 18 inches.
(B) Nonresidential construction.
(1) New construction or substantial improvement of any commercial, industrial, or nonresidential building (or manufactured home) shall have the lowest floor, including basement, elevated to or above the base flood level, plus 18 inches.
(2) Nonresidential buildings located in all AE zones (as defined on the FIRM) may be flood proofed in lieu of being elevated provided that all areas of the building components below the elevation corresponding to the BFE plus two feet are watertight with walls substantially impermeable to the passage of water, and use structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A registered professional engineer or architect shall certify that the standards of this division (B) are satisfied. Such certification, including the specific elevation (in relation to mean sea level) to which such structures are flood proofed, shall be maintained by the Floodplain Administrator.
(C) Space below the lowest floor. In zones A and AE (as defined on the FIRM), fully enclosed areas, of new construction or substantially improved structures, which are below the regulatory flood protection elevation shall:
(1) Not be designed or used for human habitation, but shall be used solely for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises. Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment (standard exterior door), or entry to the living area (stairway or elevator). Be constructed entirely of flood-resistant materials below the regulatory flood protection elevation; and
(2) Include measures to automatically equalize hydrostatic flood forces on walls by allowing for the entry and exit of floodwaters. To meet this requirement, the openings must either be certified by a professional engineer or architect or meet the following minimum design criteria:
(a) Provide a minimum of two openings on different sides of each enclosed area subject to flooding;
(b) The total net area of all openings must be at least one square inch for each square foot of enclosed area subject to flooding;
(c) If a building has more than one enclosed area, each area must have openings to allow floodwaters to automatically enter and exit;
(d) The bottom of all required openings shall be no higher than one foot above the adjacent grade;
(e) Openings may be equipped with screens, louvers, or other opening coverings or devices, provided they permit the automatic flow of floodwaters in both directions; and
(f) Foundation enclosures made of flexible skirting are not considered enclosures for regulatory purposes, and, therefore, do not require openings. Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires openings as outlined above.
(D) Standards for manufactured homes and recreational vehicles.
(1) In zones A and AE (as defined on the FIRM), all manufactured homes placed, or substantially improved, on individual lots or parcels, must meet all the requirements for new construction, including the elevation and anchoring requirements in the general standards section, and the elevation and construction standards section of this chapter.
(2) All recreational vehicles placed on sites must either:
(a) Be on the site for fewer than 180 consecutive days, be fully licensed and ready for highway use (a recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions); or
(b) Meet all the standards for manufactured homes in this chapter.
(1998 Code, § 26-47) Penalty, see § 151.99