(a) Residential Construction.
(1) New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above the base flood elevation.
(2) In AO zones new construction and substantial improvements shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as the depth number on the City's Flood Insurance Rate Map, or at least two feet if no depth number is specified, and adequate drainage paths shall be provided around structures on slopes, to guide floodwaters around and away from proposed structures.
(b) Nonresidential Construction.
(1) New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to or above the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:
A. Be floodproofed so that the structure is watertight with walls substantially impermeable to the passage of water to the level of the base flood elevation. In order to be eligible for lower flood insurance rates, the structure should be floodproofed at least one foot above the base flood elevation;
B. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and,
C. 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 1311.14.
(2) In AO zones new construction and substantial improvements shall either have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as the depth number on the City’s Flood Insurance Rate Map (at least two feet if no depth number is specified); or be floodproofed to that level consistent with the floodproofing standards of Section 1311.19(b), and adequate drainage paths shall be provided around structures on slopes, to guide floodwaters around and away from proposed structures.
(c) Accessory Structures.
(1) A relief to the elevation or dry floodproofing standards may be granted for accessory structures (e.g., sheds, detached garages) containing no more than 576 square. Such structures must meet the encroachment provisions of Section 1311.21, Floodways, and the following additional standards:
A. They shall not be used for human habitation;
B. They shall be constructed of flood resistant materials;
C. They shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of flood waters;
D. They shall be firmly anchored to prevent flotation;
E. Service facilities such as electrical and heating equipment shall be elevated or floodproofed to or above the level of the base flood elevation; and,
(d) Manufactured Homes and Recreational Vehicles. The following standards shall apply to all new and substantially improved manufactured homes not subject to the manufactured home park requirements of Section 3733.01, Ohio Revised Code:
(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.
These standards shall also apply to all recreational vehicles that are either (1) located on sites for 180 days or more, or (2) are not fully licensed and ready for highway use.
(e) Enclosures below the Lowest Floor. The following standards apply to all new and substantially improved residential and nonresidential non-basement structures which are elevated to the base flood elevation using pilings, columns, posts, or solid foundation perimeter walls with openings sufficient to allow unimpeded movement of flood waters. Fully enclosed areas below the lowest floor that are useable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must:
(1) Be certified by a registered professional engineer or architect; or,
(2) Must meet or exceed 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 shall be provided.
B. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(f) Subdivisions and Large Developments. In all areas of special flood hazard where base flood elevation data have not been provided in accordance with Section 1311.07 or Section 1311.17(b), the following standards apply to all subdivision proposals, including manufactured home subdivisions, and other proposed developments containing at least 50 lots or 5 acres (whichever is less):
(1) The applicant shall provide base flood elevation data performed in accordance with standard engineering practices;
(Ord. 2002-101. Passed 11-19-02.)