(a) General standards.
(1) No permit for floodplain development shall be granted for new construction, substantial improvements, and other improvements, including the placement of manufactured homes, within any numbered or unnumbered A zones, AE, AO, and AH zones, unless the conditions of this section are satisfied.
(2) All areas identified as unnumbered A zones on the FIRM are subject to inundation of the 100-year flood; however, the base flood elevation is not provided. Development within unnumbered A zones is subject to all provisions of this chapter. If Flood Insurance Study data is not available, the community shall obtain, review and reasonably utilize any base flood elevation or floodway data currently available from federal, state or other sources.
(3) Until a floodway is designated, no new construction, substantial improvements or other development, including fill, shall be permitted within any unnumbered or numbered A zones, or AE zones on the FIRM, unless it is demonstrated 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.
(4) All new construction, subdivision proposals, substantial improvements, prefabricated structures, placement of manufactured homes and other developments shall require:
(A) Design or adequate anchorage to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;
(B) Construction with materials resistant to flood damage;
(C) Utilization of methods and practices that minimize flood damages;
(D) All electrical, heating, ventilation, plumbing, air-conditioning equipment and other service facilities be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding;
(E) New or replacement water supply systems and/or sanitary sewage systems be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters, and on-site waste disposal systems be located so as to avoid impairment or contamination from them during flooding; and
(F) Subdivision proposals and other proposed new development, including manufactured home parks or subdivisions, located within special flood hazard areas are required to assure that:
(i) All such proposals are consistent with the need to minimize flood damage;
(ii) All public utilities and facilities, such as sewer, gas, electrical and water systems are located and constructed to minimize or eliminate flood damage;
(iii) Adequate drainage is provided so as to reduce exposure to flood hazards; and
(iv) All proposals for development, including proposals for manufactured home parks and subdivisions, of five acres or 50 lots, whichever is lesser, include within such proposals base flood elevation data.
(5) Storage, material and equipment.
(A) The storage or processing of materials within the special flood hazard area that are in time of flooding buoyant, flammable, explosive or could be injurious to human, animal or plant life is prohibited.
(B) Storage of other material or equipment may be allowed if not subject to major damage by floods, if firmly anchored to prevent flotation, or if readily removable from the area within the time available after a flood warning.
(6) Nonconforming use: a structure, or the use of a structure or premises that was lawful before the passage or amendment of the chapter, but which is not in conformity with the provisions of this chapter, may be continued subject to the following conditions:
(A) If such structure, use or utility service is discontinued for 12 consecutive months, any future use of the building shall conform to this chapter;
(B) If any nonconforming use or structure is destroyed by any means, including flood, it shall not be reconstructed if the cost is more than 50% of the pre-damaged market value of the structure. This limitation does not include the cost of any alteration to comply with existing state or local health, sanitary, building, safety codes, regulations or the cost of any alteration of a structure listed on the National Register of Historic Places, the State Inventory of Historic Places or local inventory of historic places upon determination.
(b) Specific standards. In all areas identified as numbered and unnumbered A zones, AE, and AH Zones, where base flood elevation data have been provided, as set forth in division (a)(2) above, the following provisions are required:
(1) Residential construction. New construction or substantial improvement of any residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated a minimum of one foot above base flood elevation. The elevation of the lowest floor shall be certified by a licensed land surveyor or professional engineer;
(2) Non-residential construction. New construction or substantial improvement of any commercial, industrial or other non-residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated a minimum of one foot above the base flood elevation or, together with attendant utility and sanitary facilities, be dry floodproofed to a minimum of one foot above the base flood elevation. A registered professional engineer or architect shall certify that the standards of this division (b)(2) are satisfied. The elevation of the lowest floor shall be certified by a licensed land surveyor or professional engineer. Such certification shall be provided to the Floodplain Administrator as set forth in § 16-403(c)(7) through (c)(9); and
(3) Required. Require, for all new construction and substantial improvements, that fully enclosed areas below lowest floor used solely for parking of vehicles, building access or storage in an area other than a basement and that 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 either be certified by a registered professional engineer or architect or meet or exceed the following minimum 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; and
(B) The bottom of all opening 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.
(c) Manufactured homes.
(1) All manufactured homes to be placed within all unnumbered and numbered A zones, AE and AH zones, on the community’s FIRM shall be required to be installed using methods and practices that minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse or 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.
(2) Require manufactured homes that are placed or substantially improved within unnumbered or numbered A zones, AE and AH zones, on the community’s FIRM on sites:
(A) Outside of a manufactured home park or subdivision;
(B) In a new manufactured home park or subdivision;
(C) In an expansion to and existing manufactured home park or subdivision; or
(D) In an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as the result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated a minimum of one foot above the base flood elevation and be securely attached to an adequately anchored foundation system to resist flotation, collapse and lateral movement. The elevation of the lowest floor shall be certified by a licensed land surveyor or professional engineer.
(3) Require that manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within all unnumbered and numbered A zones, AE and AH zones, on the community’s FIRM, that are not subject to the provisions of division (c)(2)above, be elevated so that either:
(A) The lowest floor of the manufactured home is a minimum of one foot above the base flood level; or
(B) The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and be securely attached to an adequately anchored foundation system to resist flotation, collapse, and lateral movement. The elevation of the lowest floor shall be certified by a licensed land surveyor or professional engineer.
(d) Areas of shallow flooding (AO and AH zones). Located within the areas of special flood hazard as described in 16-402(a) are areas designated as AO zones. 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. The following provisions apply:
(1) AO zones.
(A) All new construction and substantial improvements of residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community’s FIRM (at least two feet if no depth number is specified);
(B) All new construction and substantial improvements of any commercial, industrial or other non-residential structures, including manufactured homes, shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community FIRM (at least two feet if no depth number is specified) or together with attendant utilities and sanitary facilities be completely floodproofed to that level so that the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
(C) Adequate drainage paths shall be required around structures on slopes, in order to guide floodwaters around and away from proposed structures.
(2) AH zones.
(A) The specific standards for all areas of special flood hazard where base flood elevation has been provided shall be required as set forth in division (b) above; and
(B) Adequate drainage paths shall be required around structures on slopes, in order to guide floodwaters around and away from proposed structures.
(e) Floodway. Located within areas of special flood hazard established in division (a) above are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters that carry debris and potential projectiles, the following provisions shall apply:
(1) The community shall select and adopt a regulatory floodway based on the principle that the area chosen for the regulatory floodway must be designed to carry the waters of the base flood without increasing the water surface elevation of that flood more than one foot at any point;
(2) The community shall prohibit any encroachments, including fill, new construction, substantial improvements and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge;
(3) If division (e)(2) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section; and
(4) In unnumbered A zones, the community shall obtain, review and reasonably utilize any base flood elevation or floodway data currently available from federal, state or other sources as set forth in division (a)(2) above.
(f) Recreational vehicles. Require that recreational vehicles placed on sites within all unnumbered and numbered A Zones, AE, AH and AO Zones on the community’s FIRM 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 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.); or
(3) Meet the permitting, elevation and anchoring requirements for manufactured homes of this chapter.
(Ord. 1977, passed 6-12-2014)