(A) Permitted uses. Permitted uses are those uses of land or structures allowed in the underlying zoning district(s) that comply with the standards in division (B). If no pre-existing, underlying zoning districts exist, then any residential or nonresidential structure or use of a structure or land is a permitted use provided it does not constitute a public nuisance.
(B) Standards for flood fringe permitted uses.
(1) (a) All structures, including accessory structures, must be elevated on fill so that the lowest floor, as defined, is at or above the regulatory flood protection elevation. The finished fill elevation for structures must be no lower than one foot below the regulatory flood protection elevation and the fill must extend at the same elevation at least 15 feet beyond the outside limits of the structure.
(b) As an alternative to elevation on fill, an accessory structure that constitutes a minimal investment and that does not exceed 576 square feet in size may be internally floodproofed in accordance with § 154.089.
(2) The cumulative placement of fill or similar material on a parcel must not exceed 1,000 cubic yards, unless the fill is specifically intended to elevate a structure in accordance with division (B)(1) above, or if allowed as a conditional use under division (C)(3) below.
(3) The storage of any materials or equipment must be elevated on fill to the regulatory flood protection elevation.
(4) 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.
(5) Fill must be properly compacted and the slopes must be properly protected by the use of riprap, vegetative cover or other acceptable method.
(6) All new principal structures must have vehicular access at or above an elevation not more than two feet below the regulatory flood protection elevation, or must have a flood warning /emergency evacuation plan acceptable to the City Council.
(7) Accessory uses such as yards, railroad tracks, and parking lots may be at an elevation lower than the regulatory flood protection elevation. However, any facilities used by employees or the general public must be designed with a flood warning system that provides adequate time for evacuation if the area is inundated to a depth and velocity such that the depth (in feet) multiplied by the velocity (in feet per second) would exceed a product of four upon occurrence of the regional (1% chance) flood.
(8) Interference with normal manufacturing/industrial plant operations must be minimized, especially along streams having protracted flood durations. In considering permit applications, due consideration must be given to the needs of industries with operations that require a floodplain location.
(9) Flood fringe developments must not adversely affect the hydraulic capacity of the channel and adjoining floodplain of any tributary watercourse or drainage system.
(10) Manufactured homes and recreational vehicles must meet the standards of § 154.094.
(C) Conditional uses. The following uses and activities may be allowed as conditional uses, if allowed in the underlying zoning district(s) or any applicable overlay district, following the procedures in § 154.095(D) below. Conditional uses must meet the standards in divisions (B)(4) through (B)(10) above, and division (D) below.
(1) Any structure that is not elevated on fill or floodproofed in accordance with division (B)(1) above.
(2) Storage of any material or equipment below the regulatory flood protection elevation.
(3) The cumulative placement of more than 1,000 cubic yards of fill when the fill is not being used to elevate a structure in accordance with division (B)(1) above.
(D) Standards for flood fringe conditional uses.
(1) The standards listed in divisions (B)(4) to (B)(10) above apply to all conditional uses.
(2) Alternative elevation methods other than the use of fill may be utilized to elevate a structure's lowest floor above the regulatory flood protection elevation. These alternative methods may include the use of stilts, pilings, parallel walls, etc., or above-grade, enclosed areas such as crawl spaces or tuck-under garages. The base or floor of an enclosed area is 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. These alternative elevation methods are subject to the following additional standards:
(a) 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 building code and, specifically, that all electrical, heating, ventilation, plumbing and air conditioning equipment, including ductwork, and other service facilities are placed at or above the regulatory flood protection elevation or are designed to prevent flood water from entering or accumulating within these components during times of flooding.
(b) 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. The design plans must stipulate:
1. A minimum area of openings in the walls where internal flooding is to be used as a floodproofing technique. There must be a minimum of two openings on at least two sides of the structure and the bottom of all openings must be a maximum of one foot above grade. The automatic openings must have a net area of at least one square inch for every square foot of enclosed area subject to flooding, unless a registered professional engineer or architect certifies that a smaller net area would suffice. The automatic openings may be equipped with screens, louvers, valves, or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters without any form of human intervention; and
2. That the enclosed area will be designed of flood resistant materials in accordance with the FP-3 or FP-4 classifications in the State Building Code and will be used solely for building access, parking of vehicles, or storage.
(3) Basements, as defined by § 154.087 above, are subject to the following:
(a) Residential basement construction is not 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 floodproofed in accordance with division (B)(4) below.
(4) All areas of nonresidential structures, including basements, to be placed below the regulatory flood protection elevation must be floodproofed in accordance with the structurally dry floodproofing classifications in the State Building Code. Structurally dry floodproofing must meet the FP-1 or FP-2 floodproofing classification in the State Building Code, which requires making the structure watertight with the walls substantially impermeable to the passage of water and with structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. Structures wet floodproofed to the FP-3 or FP-4 classification are not permitted.
(5) The placement of more than 1,000 cubic yards of fill or other similar material on a parcel (other than for the purpose of elevating a structure to the regulatory flood protection elevation) must comply with an approved erosion/sedimentation control plan.
(a) The plan must clearly specify methods to be used to stabilize the fill on site for a flood event at a minimum of the regional (1% chance) flood event.
(b) The plan must be prepared and certified by a registered professional engineer or other qualified individual acceptable to the City Council.
(c) The plan may incorporate alternative procedures for removal of the material from the floodplain if adequate flood warning time exists.
(6) Storage of materials and equipment below the regulatory flood protection elevation must comply with an approved emergency plan providing for removal of such materials within the time available after a flood warning.
(2004 Code, § 154.089) (Ord. 464, passed 1- -1996; Ord. 98-223, passed 5-12-1998; Ord. 14-0729, passed 6-10-2014)