In all special flood hazard areas where base flood elevation data have been provided, as set forth in § 152.03, the following provisions are required:
(A) Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, mechanical equipment, and ductwork elevated no lower than 2 feet above the base flood elevation. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate automatic equalization of hydrostatic flood forces on walls shall be provided in accordance with standards of § 152.41.
(1) In an AO zone, the lowest floor shall be elevated above the highest adjacent grade to a height equal to or higher than the depth number specified in feet on the FIRM, or elevated at least 2 feet above the highest adjacent grade if no depth number is specified.
(2) In an A zone, where no technical data has been produced by the Federal Emergency Management Agency, the Floodplain Administrator will determine the method by which base flood elevations are determined. Methods include, but are not limited to, detailed hydrologic and hydraulic analyses, use of existing data available from other sources, approximate methods, use of historical data, best supportable and reasonable judgement in the event no data can be produced. The lowest floor shall be elevated no lower than 2 feet above such base flood elevation. Title 401 KAR (Kentucky Administrative Regulations) Chapter 4, Regulation 060, Section 5(5)a, states as a part of the technical requirements for a state floodplain permit: The applicant shall provide cross sections for determining floodway boundaries (and thereby Base Flood Elevations) at any proposed construction site where FEMA maps are not available. All cross sections shall be referenced to mean sea level and shall have vertical error tolerances of no more than +0.5 foot. Cross sections elevations shall be taken at those points which represent significant breaks in slope and at points where hydraulic characteristics of the base floodplain change. Each cross section shall extend across the entire base floodplain and shall be in the number and at the locations specified by the cabinet. If necessary to ensure that significant flood damage will not occur, the cabinet may require additional cross sections or specific site elevations which extend beyond those needed for making routine regulatory floodway boundary calculations.
(3) In all other Zones, elevated 2 feet above the base flood elevation. Upon the completion of the structure, the elevation of the lowest floor (including basement) shall be certified by a registered professional engineer or surveyor, and verified by the community building inspection department to be properly elevated. Such certification and verification shall be provided to the Floodplain Administrator.
(B) Non-residential construction. New construction and substantial improvement of any commercial, industrial, or non-residential structure (including manufactured homes used for non-residential purposes) shall be elevated to conform with § 152.41 or together with attendant utility and sanitary facilities:
(1) Be floodproofed to an elevation 10 feet (2 feet from base with 8 feet first floor) above the level of the base flood elevation so that 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 debris;
(3) A registered professional engineer or architect shall certify that the standards of this section are satisfied. Such certification along with the design and operational maintenance plans shall be provided to the Floodplain Administrator.
(4) Manufactured homes shall meet the standards in § 152.41.
(5) All new construction and substantial improvement with fully enclosed areas below the lowest floor (including basements) that are usable solely for parking of vehicles, building access or storage, and which are subject to flooding, shall be constructed of flood resistant materials to an elevation 10 feet above the base flood elevation, and, shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Openings for meeting this requirement must meet or exceed the standards of § 152.41.
(C) Elevated structures. New construction and substantial improvements of elevated structures on columns, posts, or pilings that include fully enclosed areas formed by foundation and other exterior walls below the lowest floor shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls.
(1) Openings for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria:
(a) Provide a minimum of 2 openings having a total net area of not less than 1 square inch for every square foot of enclosed area subject to flooding;
(b) The bottom of all openings shall be no higher than 1 foot above foundation interior grade (which must be equal to in elevation or higher than the exterior foundation grade); and
(c) Openings may be equipped with screens, louvers, valves, or other coverings or devices provided they permit the automatic flow of floodwaters in both directions.
(2) Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door), limited storage of maintenance equipment used in connection with the premises (standard exterior door), or entry to the living area (stairway or elevator); and
(3) The interior portion of such enclosed areas shall not be finished or partitioned into separate rooms.
(D) Floodways. Located within areas of special flood hazard established in § 152.03, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and has erosion potential, the following provisions shall apply:
(1) Prohibit encroachments, including fill, new construction, substantial improvements, and other developments unless certification (with supporting technical data) by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in the base flood elevation levels during occurrence of base flood discharge;
(Ord. O-2012-011, passed 5-21-2012)