(A) General standards. In all flood prone areas. the following provisions are required.
(1) New construction and substantial improvements to existing buildings shall be anchored to prevent flotation, collapse or lateral movement of the structure.
(2) Manufactured homes shall be installed using methods and practices that minimize flood damage. They must be elevated and anchored to prevent flotation, collapse and lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.
(3) New construction and substantial improvements to existing buildings shall be constructed with materials and utility equipment resistant to flood damage.
(4) New construction and substantial improvements shall be constructed by methods and practices that minimize flood damage.
(5) All electrical, heating, ventilation, plumbing, air conditioning equipment and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
(6) New and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.
(7) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters.
(8) On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
(9) Any alteration, repair, reconstruction or improvements to a building that is in compliance with the provisions of this chapter, shall meet the requirements of "new construction" as contained in this chapter.
(10) Any alteration, repair, reconstruction or improvements to a building that are not in compliance with the provision of this chapter, shall be undertaken only if the non-conformity is not further extended or replaced.
(11) All new construction and substantial improvement proposals shall provide copies of all necessary federal and state permits, including § 404 of the Federal Water Pollution Control Act amendments of 1972, 33 U.S.C. § 1334.
(12) All subdivision proposals and other proposed new development proposals shall meet the standards of division (B) below.
(13) When proposed new construction and substantial improvements are partially located in an area of special flood hazard, the entire structure shall meet the standards for new construction.
(14) When proposed new construction and substantial improvements are located in multiple flood hazard risk zones or in a flood hazard risk zone with multiple base flood elevations, the entire structure shall meet the standards for the most hazardous flood hazard risk zone and the highest base flood elevation.
(B) Specific standards. In all areas of special flood hazard, the following provisions, in addition to those set forth in division (A) above are required.
(1) Residential construction. In AE Zones where base flood elevation data is available, new construction or substantial improvement of any residential building (or manufactured home) shall have the lowest floor, including basement, 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 equalization of flood hydrostatic forces on both sides of exterior walls shall be provided in accordance with the standards of this section: “Enclosures” [division (B)(3) below].Within approximate A zones, where base flood elevations have not been established and where alternative data is not available, the Administrator shall require the lowest floor of a building to be elevated to a level of at least three feet above the highest adjacent grade (as defined in § 14-302 of this chapter). Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate equalization of flood hydrostatic forces on both sides of exterior walls shall be provided in accordance with the standards of this section: “Enclosures” [division (B)(3) below].
(2) Non-residential structures.
(a) In AE Zones, where base flood elevation data is available, new construction and substantial improvement of any commercial, industrial or non-residential building, shall have the lowest floor, including basement, elevated or flood-proofed to no lower than one foot above the level of the base flood elevation.
(b) Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate equalization of flood hydrostatic forces on both sides of exterior walls shall be provided in accordance with the standards of this section: "Enclosures" [division (B)(3) below].
(c) In approximate A zones, where base flood elevations have not been established and where alternative data is not available, new construction and substantial improvement of any commercial, industrial or non-residential building, shall have the lowest floor, including basement, elevated or flood- proofed to no lower than three feet above the highest adjacent grade (as defined in § 14-302 of this chapter). Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate equalization of flood hydrostatic forces on both sides of exterior walls shall be provided in accordance with the standards of this section: "Enclosures" [division (B)(3) below].
(d) Non-residential buildings located in all A-zones may be flood-proofed, in lieu of being elevated; provided that, all areas of the building below the required elevation are watertight, with walls substantially impermeable to the passage of water, and are built with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. A state registered professional engineer or architect shall certify that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions above, and shall provide the certification to the Administrator as set forth in § 14-304(B).
(3) Enclosures. All new construction and substantial improvements that include fully enclosed areas formed by foundation and other exterior walls below the lowest floor that are subject to flooding, 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.
(a) Designs for complying with this requirement must either be certified by a state professional engineer or architect or meet the following minimum criteria:
1. 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;
2. The bottom of all openings shall be no higher than one foot above the finish grade; and
3. 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.
(b) The enclosed area shall be the minimum necessary to allow for parking of vehicles, storage or building access; and
(c) The interior portion of the enclosed area shall not be finished or partitioned into separate rooms in such a way as to impede the movement of flood waters and all petitions shall comply with the provisions of division (B) of this section.
(4) Standards for manufactured homes and recreational vehicles.
(a) All manufactured homes placed or substantially improved, on:
1. Individual lots or parcels;
2. In expansions to existing manufactured home parks or subdivisions; or
3. In new or substantially improved manufactured home parks or subdivisions, must meet all the requirements of new construction.
(b) All manufactured homes placed or substantially improved in an existing manufactured home park or subdivision must be elevated so that either:
1. In AE Zones, with base flood elevations, the lowest floor of the manufactured home is elevated on a permanent foundation no lower than one foot above the level of the base flood elevation; or
2. In approximate A Zones, without base flood elevations, the manufactured home chassis is elevated and supported by reinforced piers (or other foundation elements of at least equivalent strength) that are at least three feet in height above the highest adjacent grade (as defined in division (B) of this section).
(c) Any manufactured home, which has incurred "substantial damage" as the result of a flood, must meet the standards of division (A)(2) of this chapter.
(d) All manufactured homes must be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
(e) All recreational vehicles placed in an identified special flood hazard area must either:
1. Be on the site for fewer than 180 consecutive days;
2. Be fully licensed and ready for highway use. (A recreational vehicle is ready for highway use if it is licensed, on its wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached structures or additions.); or
3. The recreational vehicle must meet all the requirements for new construction.
(5) Standards for subdivisions and other proposed new development proposals. Subdivisions and other proposed new developments; including manufactured home parks, shall be reviewed to determine whether the proposals will be reasonably safe from flooding.
(a) All subdivision and other proposed new development proposals shall be consistent with the need to minimize flood damage.
(b) All subdivision and other proposed new development proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize or eliminate flood damage.
(c) All subdivision and other proposed new development proposals shall have adequate drainage provided to reduce exposure to flood hazards.
(d) In all approximate A Zones require that all new subdivision proposals and developments (including proposals for manufactured home parks and subdivisions) greater than 50 lots or five acres, whichever is the lesser, include within the proposals base flood elevation data (see division (E) below.
(C) Standards for areas of special flood hazard with established base flood elevations and with floodways designated. Located within the areas of special flood hazard established in § 14-303(B), are areas designated as floodways. A floodway may be an extremely hazardous area due to the velocity of flood waters, debris or erosion potential. In addition, the area must remain free of encroachment in order to allow for the discharge of the base flood without increased flood heights and velocities. Therefore, the following provisions shall apply.
(1) Encroachments are prohibited, including earthen fill material, new construction, substantial improvements or other developments within the regulatory floodway. Development may be permitted however; provided, it is demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practices that the cumulative effect of the proposed encroachments or new development shall not result in any increase the water surface elevation of the base flood elevation, velocities or floodway widths during the occurrence of a base flood discharge at any point within the community. A state registered professional engineer must provide supporting technical data, using the same methodologies as in the effective flood insurance study for the city and certification thereof.
(2) New construction or substantial improvements of buildings, where permitted, shall comply with all applicable flood hazard reduction provisions of division (A) above.
(D) Standards for areas of special flood hazard zones AE with established base flood elevations, but without floodways designated. Located within the special flood hazard areas established in § 14-303(B), where streams exist with base flood data provided, but where no floodways have been designated, (Zones AE) the following provisions apply.
(1) No encroachments, including fill material, new structures or substantial improvements shall be located within areas of special flood hazard, unless certification by a state registered professional engineer is provided demonstrating that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community. The engineering certification should be supported by technical data that conforms to standard hydraulic engineering principles.
(2) New construction or substantial improvements of buildings, where permitted, shall comply with all applicable flood hazard reduction provisions of division (A) above.
(E) Standards for streams without established base flood elevations and floodways (A Zones). Located within the areas of special flood hazard established in § 14-303(B), where streams exist, but no base flood data has been provided and where a floodway has not been delineated, the following provisions shall apply.
(1) The Administrator shall obtain, review and reasonably utilize any base flood elevation and floodway data available from any federal, state or other sources, including data developed as a result of these regulations (see division (E)(2) below), as criteria for requiring that new construction, substantial improvements, or other development in approximate A Zones meet the requirements of division (A) above.
(2) Require that all new subdivision proposals and other proposed developments (including proposals for manufactured home parks and subdivisions) greater than 50 lots or five acres, whichever is the lesser, include within the proposals base flood elevation data.
(3) Within approximate A Zones, where base flood elevations have not been established and where the data is not available from other sources, require the lowest floor of a building to be elevated or flood-proofed to a level of at least three feet above the highest adjacent grade (as defined in § 14-302). All applicable data including elevations or flood-proofing certifications shall be recorded as set forth in § 14-304(B). Openings sufficient to facilitate automatic equalization of hydrostatic flood forces on exterior walls shall be provided in accordance with the standards of division (B) above.
(4) Within approximate A Zones, where base flood elevations have not been established and where the data is not available from other sources, no encroachments, including structures or fill material, shall be located within an area equal to the width of the stream or 20 feet, whichever is greater, measured from the top of the stream bank, unless certification by a state registered professional engineer is provided demonstrating that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the city. The engineering certification should be supported by technical data that conforms to standard hydraulic engineering principles.
(5) New construction and substantial improvements of buildings, where permitted, shall comply with all applicable flood hazard reduction provisions of division (A)(2) above. Within approximate A Zones, require that those divisions of this section dealing with the alteration or relocation of a watercourse, assuring watercourse carrying capacities are maintained and manufactured homes provisions are complied with as required.
(F) Standards for areas of shallow flooding (AO and AH Zones). Located within the areas of special flood hazard established in § 14-303(B), are areas designated as shallow flooding areas. These areas have special flood hazards associated with base flood depths of one to three feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate; therefore, the following provisions, in addition to those set forth in division (A)(2) above apply.
(1) All new construction and substantial improvements of residential and non-residential buildings shall have the lowest floor, including basement, elevated to at least one foot above the flood depth number specified on the Flood Insurance Rate Map (FIRM), in feet, above the highest adjacent grade. If no flood depth number is specified on the FIRM, the lowest floor, including basement, shall be elevated, at least three feet above the highest adjacent grade. Openings sufficient to facilitate automatic equalization of hydrostatic flood forces on exterior walls shall be provided in accordance with standards of division (B) above.
(2) All new construction and substantial improvements of non-residential buildings may be flood-proofed in lieu of elevation. The structure together with attendant utility and sanitary facilities must be flood-proofed and designed watertight to be completely flood-proofed to at least one foot above the flood depth number specified on the FIRM, with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. If no depth number is specified on the FIRM, the structure shall be flood proofed to at least three feet above the highest adjacent grade. A state registered professional engineer or architect shall certify that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions of this chapter and shall provide such certification to the Administrator as set forth above and as required in § 14-304(B).
(3) Adequate drainage paths shall be provided around slopes to guide flood waters around and away from proposed structures.
(G) Standards for areas protected by flood protection system (A-99 Zones). Located within the areas of special flood hazard established in § 14-303(B) are areas of the 100-year floodplain protected by a flood protection system, but where base flood elevations have not been determined. Within these areas (A-99 Zones) all provisions of § 14-304 and this section shall apply.
(H) Standards for unmapped streams. Located within the city are unmapped streams where areas of special flood hazard are neither indicated nor identified. Adjacent to the streams the following provisions shall apply.
(1) No encroachments including fill material or other development including structures shall be located within an area of at least equal to twice the width of the stream, measured from the top of each stream bank, unless certification by a state registered professional engineer is provided demonstrating that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the locality.
(2) When a new flood hazard risk zone, and base flood elevation and floodway data is available, new construction and substantial improvements shall meet the standards established in accordance with §§ 14-304 and this section.
(1989 Code, § 14-305) (Ord. 1143, passed 9-25-2007; Ord. 1219, passed 6-9-2009)