(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 the fill requirements of division (A) above, structures accessory to the uses identified in § 153.080 may be permitted to be internally/wet floodproofed to the FP-3 or FP-4 floodproofing classifications in the State Building Code, provided that:
(1) The accessory structure constitutes a minimal investment, does not exceed 576 square feet in size, and is only used for parking and storage;
(2) All portions of floodproofed accessory structures below the regulatory flood protection elevation must be:
(a) Adequately anchored to prevent flotation, collapse, or lateral movement and designed to equalize hydrostatic flood forces on exterior walls;
(b) Be constructed with materials resistant to flood damage; and
(c) Must have all service utilities be watertight or elevated to above the regulatory flood protection elevation.
(3) Designs for meeting this requirement must either be certified by a registered professional engineer or meet or exceed the following criteria:
(a) To allow for the equalization of hydrostatic pressure, there must be a minimum of two “automatic” openings in the outside walls of the structure, with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding; and
(b) There must be openings on at least two sides of the structure and the bottom of all openings must be no higher than one foot above the lowest adjacent grade to the structure. Using human intervention to open a garage door prior to flooding will not satisfy this requirement for automatic openings.
(4) 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 (A) above, or if allowed as a conditional use under § 153.082;
(5) The storage of any materials or equipment must be elevated on fill to the regulatory flood protection elevation;
(6) All service utilities, including ductwork, must be elevated or watertight to prevent infiltration of flood waters;
(7) All fill must be properly compacted and the slopes must be properly protected by the use of riprap, vegetative cover or other acceptable method;
(8) 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;
(9) 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; and
(Ord. 2017-03, passed 7-24-2017)