(A) Permitted uses. Permitted uses shall be those uses of land or structures listed as permitted uses in the underlying zoning use district(s). If no preexisting, underlying zoning use structure or land shall be a permitted use in the flood fringe provided such use does not constitute a public nuisance. All permitted uses shall comply with the standards for flood fringe ‘’permitted uses’‘ listed in division (E) below.
(B) Standards for flood fringe permitted uses.
(1) All structures, including accessory structures, must be elevated on fill so that the lowest floor, including basement floor, is at or above the regulatory flood protection elevation. The finished fill elevation for structures shall be no lower than one foot below the regulatory flood protection elevation and the fill shall extend at such elevation at least 15 feet beyond the outside limits of the structure erected thereon.
(2) As an alternative to elevation on fill, accessory structures that constitute a minimal investment and that do not exceed 500 square feet for the outside dimension at ground level may be internally flood-proofed in accordance with § 908.04(D)(5)(c) of this chapter.
(3) The cumulative placement of fill where at any one time in excess of 1,000 cubic yards of fill is located on the parcel shall be allowable only as a conditional use, unless said fill is specifically intended to elevate a structure in accordance with division (B)(1) above.
(4) The storage of any materials or equipment shall be elevated on fill to the regulatory flood protection elevation.
(5) The provisions of division (E) below shall apply.
(C) Conditional uses. Any structure that is not elevated on fill or flood-proofed in accordance with divisions (B)(1) and (B)(2) above or any use of land that does not comply with the standards in divisions (B)(3) and (B)(4) above shall only be allowable as a conditional use. An application for a conditional use shall be subject to the standards and critical and evaluation procedures specified in divisions (D) and (E) below and § 908.10(D) of this chapter.
(D) Standards for flood fringe conditional uses.
(1) (a) Alternative elevation methods other than the use of fill may be utilized to elevated a structure’s lowest floor above the regulatory flood protection elevation. These alternative methods may include the sue of stilts, pilings, parallel walls and the like or above-grade, enclosed areas such as crawl spaces or tuck under garages. The base or floor of an enclosed area shall be considered above-grade and not a structure’s basement or lowest floor if:
1. The enclosed area is above-grade on at least one side of the structure;
2. It is designed to internally flood and is constructed with flood-resistant materials; and
3. It is used solely for parking of vehicles, building access or storage.
(b) The above-noted alternative elevation methods are subject to the following additional standards.
1. Design and certification. The structure’s design and as-built condition must be certified by a registered professional engineer or architect as being in compliance with the general design standards of the state’s Building Code and, specifically, that all electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities must be at or above the regulatory flood protection elevation or be designed to prevent flood water from entering or accumulating within these components during times of flooding.
2. Specific standards for above-grade, enclosed areas. Above-grade, fully enclosed areas such as crawl spaces or tuck under garages must be designed to internally flood and the design plans must stipulate:
a. The minimum area of openings in the walls where internal flooding is to be sued as a flood-proofing technique. When openings are placed in a structure’s walls to provide for entry of flood waters to equalize pressures, 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 waters; and
b. That the enclosed area will be designed of flood resistant materials in accordance with the FP-3 or FP-4 classifications in the state’s Building Code and shall be used solely for building access, parking of vehicles or storage.
(2) Basements, as defined by § 908.02(H) of this chapter, shall be subject to the following.
(a) Residential basement construction shall not be allowed below the regulatory flood protection elevation.
(b) Non-residential basements may be allowed below the regulatory flood protection elevation; provided, the basement is structurally dry flood-proofed in accordance with division (D)(3) below.
(3) All areas of non-residential structures including basements to be placed below the regulatory flood protection elevation shall be flood-proofed in accordance with the structurally dry flood- proofing classifications in the state’s Building Code. Structurally dry flood-proofing must meet the FP-1 or FP-2 flood-proofing classification in the state’s Building Code and this shall require making the structure water-tight with the 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. Structures flood-proofed to the FP-3 or FP-4 classification shall not be permitted.
(4) When at any one time more than 1,000 cubic yards of fill or other similar materials is located on a parcel for such activities as on-site storage landscaping and gravel operations, landfills, roads, dredge spoil disposal or construction of flood control works, an erosion/sedimentation control plan must be submitted unless the community is enforcing a state-approved shoreline management ordinance. In the absence of a state-approved shoreland ordinance, the plan must clearly specify methods to be used to stabilize the fill on site for a flood event at a minimum of the 100-year or regional flood event. The plan must be prepared and certified by a registered professional engineer or other qualified individual acceptable to the governing body. The plan may incorporate alternative procedures for removal of the material from the floodplain if adequate flood warning time exists.
(5) Storage of materials and equipment:
(a) The storage or processing of materials that are, in time of flooding, flammable, explosive or potentially injurious to human, animal or plant life is prohibited.
(b) Storage of other materials or equipment may be allowed if readily removable from the area within the time available after a flood warning and in accordance with a plan approved by the governing body.
(6) The provisions for division (E) below shall also apply.
(E) Standards for all flood fringe uses.
(1) All new principal structures must have vehicular access at or above an elevation not more than two feet below the regulatory flood protection elevation. If a variance to this requirement is granted, the Board of Adjustment must specify limitations on the period of use or occupancy of the structure for times of flooding and only after determining that adequate flood warning time and local flood emergency response procedures exist.
(2) Accessory land uses, such as yards, railroad tracks and parking lots may be at elevations lower than the regulatory flood protection elevation. However, a permit for such facilities to be used by the employees or general public shall not be granted in the absence of a flood warning system that provides adequate time for evacuation if the area would be inundated to a depth greater than two feet or be subject to flood velocities greater than four feet per second upon occurrence of the regional flood.
(3) Measures shall be taken to minimize interference with normal plan operations especially along streams having protracted flood duration. Certain accessory land uses such as yards and parking lots may be at lower elevations subject to requirements set out in division (E)(2) above. In considering permit applications, due consideration shall be given to needs of an industry whose business requires that it be located in floodplain areas.
(4) Fill shall be properly compacted and the slopes shall be properly protects by the use of rip rap, vegetative cover or other acceptable method. The Federal Emergency Management Agency (FEMA) has established criteria for removing the special flood hazard area designation for certain structures properly elevated on fill above the 100-year flood elevation, FEMA’s requirements incorporated specific fill compaction and side slope protection standards for multi-structure or multi-lot developments. These standards should be investigated prior to the initiation of site preparation if a change of special flood hazard area designation will be requested.
(5) Floodplain developments shall not adversely affect the hydraulic capacity of the channel and adjoining floodplain of any tributary watercourse or drainage system where a floodway or other encroachment limit has not been specified on the official zoning map.
(6) Standards for travel trailers and travel vehicles are contained in § 908.09(C) of this chapter.
(7) All manufactured homes must be securely anchored to an adequately anchored foundation system that resists floatation, collapse and lateral movement. Methods of anchoring may include, but are not to be limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable state or local anchoring requirements for resisting wind forces.