In all special flood hazard areas where base flood elevation data has been provided, as set forth in § 151.07 of this chapter, the following provisions are required.
(A) Residential construction.
(1) 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 one foot above the base flood elevation. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of flood waters 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 exceeding the depth number of specified in feet on the FIRM by at least one foot, or elevated at least three 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 one foot 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 judgment in the event no data can be produced. Title 401 KAR (Kentucky Administrative Regulations) Ch. 4, Reg. 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 plus five-tenths (+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”.
(c) In all other zones, the lowest floor shall be elevated at least one foot 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.
(3) (a) Freeboard requirements add height above the base flood elevation to account for future flood fringe development, uncertainties inherent with the methodologies, lack of data, debris that accompanies the base flood, and flood levels higher than that of the base flood. A freeboard requirement means that new construction and substantial improvements of existing structures will be protected to a level higher than the base flood elevation.
(b) Freeboard is applied not just to the elevation of the lowest floor or flood- proofing level, but also to the level of protection provided to all components of the structure. All structure utilities, including ductwork, must be elevated or protected to the freeboard level and all portions of the structure below the freeboard level must be constructed using materials resistant to flood damage. If the lowest floor of garages or accessory structures is below the freeboard level, the structure must meet the opening requirements of division (C) below.
(4) Two references on these requirements are Protecting Building Utilities from Flood Damage, FEMA-348, and Flood Resistant Materials Requirements, FIA-TB-2.
(B) Non-residential construction. New construction or substantial improvement of any commercial, industrial or non-residential structure (including manufactured home used for non-residential purposes) shall be elevated to conform with division (A) above or together with attendant utility and sanitary facilities:
(1) Be flood-proofed below an elevation one foot above the level of the base flood elevation so that the structure is water-tight 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 one foot above the level of the base flood elevation;
(4) A registered professional engineer or architect shall certify that the standards of this subsection are satisfied. Such certification shall be provided to the official as set forth in § 151.26(A)(3) of this chapter;
(5) Manufactured homes shall meet the standards in division (D) below;
(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 one foot 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 flood water. Opening sizes (FEMA Technical Bulletin 1-93) 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 flood water.
(C) Elevated buildings. New construction or substantial improvements of elevated structures on columns, posts or pilings (e.g., 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 flood waters 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 foot of enclosed area subject to flooding;
(b) The bottom of all openings shall be no higher than one foot above grade 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 flood waters 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 area shall not be partitioned or finished into separate rooms;
(4) The total floor area of all such enclosed areas shall not exceed 300 square feet; and
(5) For enclosures greater than seven feet in interior height, where elevation requirements exceed six feet above the highest adjacent grade, a copy of the legally recorded deed restriction prohibiting the conversion of the area below the lowest floor to a use or dimension contrary to the structures’ originally approved design, shall be presented as a condition of issue of the final certificate of occupancy.
(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. Locations include:
(a) On individual lots or parcels;
(b) In expansions to existing manufactured home parks or subdivisions;
(c) In new manufactured home parks or subdivisions;
(d) In substantially improved manufactured home parks or subdivisions;
(e) Outside of a manufactured home park or subdivision; or
(f) 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,
(2) All manufactured homes must be:
(a) Elevated on a permanent foundation;
(b) Have its lowest floor elevated no lower than one foot above the level of the base flood elevation; and
(c) Be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
(3) 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:
(a) The manufactured home is securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement, so that either the:
1. The lowest floor of the manufactured home is elevated no lower than one foot above the level of the base flood elevation; or
2. 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.
(4) 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:
(a) Be on the site fewer than 180 consecutive days;
(b) Be fully licensed and ready for highway use; or
(c) Meet the permit requirements for new construction of this chapter including anchoring and elevation requirements for “manufactured homes”.
(5) A recreational vehicle is ready for highway use if it is licensed and insured in accordance with the state motor vehicle regulations, is on it 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 § 151.07 of this chapter 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;
(2) If this division (E) is satisfied, all new construction and substantial improvements and other proposed new development shall comply with all applicable flood hazard reduction provisions of this subchapter.
(F) Standards for utilities.
(1) All new and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate:
(a) Infiltration of flood waters into the systems; and
(b) Discharge from the system into flood waters.
(2) On-site waste disposal systems shall be located to avoid impairment to them, or contamination from them during flooding.
(G) Structures elevated on fill. A residential or non-residential structure may be constructed on permanent fill in accordance with the following.
(1) The lowest floor (including basement) of the structure or addition shall be no lower than one foot above the base flood elevation.
(2) The fill shall be placed in layers no greater than one foot deep before compacting and should extend at least ten feet beyond the foundation of the structure before sloping below the base flood elevation, said slope being no greater than a two to one (2:1) ratio unless a stability analysis is provided by a registered professional engineer.
(3) The top of the fill shall be no lower than one foot above the base flood elevation. However, the ten-foot minimum may be waived if a structural engineer certifies an alternative method to protect the structure from damage due to erosion, scour and other hydrodynamic forces.
(4) The fill shall not adversely affect the flow or surface drainage from or onto neighboring properties.
(5) All new structures built on fill must be constructed on properly designed and compacted fill (ASTM D-698 or equivalent) that extends beyond the building walls before dropping below the base flood elevation and has appropriate protection from erosion and scour. The design of the fill or the fill standard must be approved by a licensed professional engineer.
(6) If the community adopts and enforces the soil testing and compaction requirements set fourth by the Standard, Uniform or National Building Codes or the International Residential and Building Codes, it may qualify for additional CRS credit.
(H) Vegetative buffer strips (riparian zones). For all activities involving construction within 25 feet of the channel, the following criteria shall be met.
(1) A natural vegetative buffer strip shall be preserved within at least 25 feet of the mean high water level of the channel.
(2) Where it is impossible to protect this buffer strip during the construction of an appropriate use, a vegetated buffer strip shall be established upon completion of construction.
(3) The use of native riparian vegetation is preferred in the buffer strip. Access through this buffer strip shall be provided for stream maintenance purposes.
(Prior Code, § 151.41) (Ord. 27-2007, passed 7-16-2007; Ord. 32-2007, passed 9-14-2007)