In all areas of special flood hazard where base flood elevation data have been provided as set forth in Sections 1476.06 and 1476.13(b), the following provisions are required:
(a) Residential Construction. New construction and substantial improvement of any residential structure shall have the lowest floor, including the basement, elevated to or above the base flood elevation.
(b) Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including the basement, elevated to the level of the base flood elevation or, together with attendant utility and sanitary facilities, shall:
(1) Be floodproofed so that below the base flood level 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 effects of buoyancy; and
(3) Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting the standards of this subsection. Such certification shall be provided to the official as set forth in Section 1476.11(a)(3).
(c) Accessory Structures. An exemption to the elevation or dry floodproofing standards may be granted for accessory structures (e.g. sheds, detached garages) containing 576 square feet or less in gross floor area. Such structures shall meet the encroachment provisions of Section 1476.17(a) and the following additional standards:
(1) Such structures shall not be used for human habitation.
(2) Such structures shall be designed to have low flood damage potential.
(3) Such structures shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of flood waters.
(4) Such structures shall be firmly anchored to prevent flotation.
(5) Service facilities such as electrical and heating equipment shall be elevated or floodproofed.
(d) Manufactured Homes. The following standards shall apply to all new and substantially improved manufactured homes not subject to the manufactured home requirements of Ohio R.C. 3733.01:
(1) Manufactured homes shall be anchored in accordance with Section 1476.15(a)(2).
(2) Manufactured homes shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above the base flood elevation.
(e) Enclosures Below Base Flood Elevation. The following provisions apply to all new and substantially improved residential and nonresidential structures which are elevated to or above the base flood elevation using pilings, columns or posts, or which contain a crawl space. These structures may enclose the area below the base flood elevation, provided that the following conditions are met:
(1) Fully enclosed areas below the base flood elevation shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of flood waters. Designs for meeting this requirement must:
A. Be certified by a registered professional engineer or architect; or
B. Meet or exceed the following criteria:
1. A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area shall be provided.
2. The bottom of all openings shall be not higher than one foot above grade.
3. Openings may be equipped with screens, louvers or other coverings or devices, provided that they permit the automatic entry and exit of flood waters.
(2) Any enclosure which meets the criteria shall be considered as having met the requirements of Section 1476.15(a).
(Ord. 89-33. Passed 9-6-89.)