(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) below.
(B) Standards for flood fringe permitted uses.
(1) 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. Elevations must be certified by a registered professional engineer, land surveyor or other qualified person designated by the community.
(2) Accessory structures. As an alternative to the fill requirements of division (B)(1) above, structures accessory to the uses identified in division (A) above may be designed to accommodate the inundation of floodwaters, meeting the following provisions, as appropriate:
(a) The accessory structure constitutes a minimal investment and satisfy the development requirements in § 154.04(B).
(b) Any enclosed accessory structure shall not exceed 576 square feet in size, and only be used for parking and storage, Any such structure shall be designed and certified by a registered professional engineer, or be designed in accordance with the following floodproofing standards: to allow for the equalization of hydrostatic pressure, there shall be a minimum of two openings on at least two sides of the structure and the bottom of all openings shall be no higher than one foot above grade. The openings shall have a minimum net area of not less than one square inch for every square foot of enclosed area subject to flooding, have a net area of not less than one square inch for every square foot of enclosed area subject to flooding, and shall allow automatic entry and exit of floodwaters without human intervention.
(3) 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.
(4) All service utilities, including ductwork, must be elevated or water-tight to prevent infiltration of floodwaters.
(5) All 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.
(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.
(C) Conditional uses. The following uses may be allowed as conditional uses following the standards and procedures set forth in § 154.11(D) and further subject to the standards set forth in division (D) below, if otherwise allowed in the underlying zoning district(s).
(1) The placement of floodproofed nonresidential basements below the regulatory flood protection elevation. Residential basements, are not allowed below the regulatory flood protection elevation.
(2) 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 (D)(1) below.
(D) Standards for flood fringe conditional uses.
(1) The standards for permitted uses in the flood fringe, listed in division (B)(4) through (8) above, apply to all conditional uses.
(2) All areas of nonresidential structures, including basements, to be placed below the regulatory flood protection elevation must be structurally dry floodproofed, 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. A floodproofing certification consistent with § 154.11(B)(2) shall be required.
(3) 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.
(c) The plan may incorporate alternative procedures for removal of the material from the floodplain if adequate flood warning time exists.
(Ord. 103, passed 10-8-01; Am. Ord. 225, passed 10-8-18)