In all special flood hazard areas where base flood elevation data have been provided, as set forth in § 152.21, the following provisions are required.
(A) Residential construction. New construction or substantial improvement of any residential structure (or manufactured home) shall have the lowest floor; including basement, mechanical equipment and ductwork elevated no lower than at or above the base flood elevation.
(1) Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of floodwaters shall be provided in accordance with standards of division (C) below.
(a) In an AO Zone, elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the FIRM, or elevated at least two feet above the highest adjacent grade if no depth number is specified.
(b) In an A Zone, where no technical data has been produced by the Federal Emergency Management Agency, elevated at or above the base flood elevation, as determined by this community. 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, use of historical data, best supportable and reasonable judgement in the event no data can be produced. Title 401 KAR (Kentucky Administrative Regulations) Chapter 4, Regulation 060, 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 five-tenths 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.
(c) In all other zones, elevated at or above the base flood elevation.
(2) 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) Nonresidential construction. New construction or substantial improvement of any commercial, industrial or nonresidential structure (including manufactured homes used for nonresidential purposes) shall be elevated to conform with division (A) above or together with attendant utility and sanitary facilities:
(1) Be floodproofed below an elevation at or 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;
(3) Have the lowest floor, including basement, mechanical equipment and ductwork, elevated no lower than at or above the level of the base flood elevation;
(4) A registered professional engineer or architect shall certify that the standards of this division (B) are satisfied. Such certification shall be provided to the official as set forth in § 152.41(B)(2)(a);
(5) Manufactured homes shall meet the standards in division (D) below; and
(6) All new construction and substantial improvement with fully enclosed areas below the lowest floor (excluding 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 below an elevation at or 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. Opening sizes (FEMA Technical Bulletin I-93) for meeting this requirement must meet or exceed the following minimum criteria:
(a) Be certified by a registered professional engineer or architect; or
(b) Have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding. 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 floodwater.
(C) Elevated structures. New construction or substantial improvements of elevated structures on columns, posts or pilings that include fully enclosed areas formed by foundation and other exterior walls below the base flood elevation 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) Opening sizes 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 two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding;
(b) The bottom of all openings shall be no higher than one 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) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator).
(3) The interior portion of such enclosed areas shall not be partitioned or finished into separate rooms.
(D) Standards for manufactured homes and recreational vehicles.
(1) All new or substantially improved manufactured homes placed on sites located within A, A1-30, AO, AH and AE on the community’s flood insurance rate map (FIRM) must meet all the requirements for new construction, including elevation and anchoring.
(a) Locations include:
1. On individual lots or parcels;
2. In expansions to existing manufactured home parks or subdivisions;
3. In new manufactured home parks or subdivisions;
4. In substantially improved manufactured home parks or subdivisions;
5. Outside of a manufactured home park or subdivision; or
6. In an existing manufactured home park or subdivision on a site upon which a manufactured home has incurred “substantial damage” as the result of a flood.
(b) All manufactured homes must be:
1. Elevated on a permanent foundation;
2. Have its lowest floor elevated no lower than at or above the level of the base flood elevation; and
3. Be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
(2) Except manufactured homes that have incurred substantial damage as a result of a flood, all manufactured homes placed or substantially improved in an existing manufactured home park or subdivision must be elevated so that the manufactured home is securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement, so that either the:
(a) The lowest floor of the manufactured home is elevated no lower than at or above the level of the base flood elevation; or
(b) The manufactured home chassis is supported by reinforced piers or other foundation elements of at least an equivalent strength, of no less than 36 inches in height above the highest adjacent grade.
(3) (a) All recreational vehicles placed on sites located within A, A1-30, AO, AH and AE on the community’s flood insurance rate map (FIRM) must either:
1. Be on the site for fewer than 180 consecutive days;
2. Be fully licensed and ready for highway use; or
3. Meet the permit requirements for new construction of this chapter, including anchoring and elevation requirements for “manufactured homes.”
(b) A recreational vehicle is ready for highway use if it is licensed and insured in accordance with the state motor vehicle regulations, 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.
(E) Floodways. Located within areas of special flood hazard established in § 152.21, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters 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. 01-05.25.10, passed 5-27-2010) Penalty, see § 152.99