(A) Permitted uses in flood fringe. Any uses or activities allowed in any applicable underlying zoning districts may be allowed with a permit, subject to the standards set forth in division (B) below.
(B) Standards for permitted uses in flood fringe. In addition to the applicable standards detailed in § 153.04:
(1) Residential structures; elevation on fill. All structures to be erected, constructed, reconstructed, altered, or moved on fill within the Flood Fringe District shall be placed so that the lowest floor, as defined in § 153.02, is elevated at or above the Regulatory Flood Protection Elevation (RFPE). The finished fill elevation shall be at or above the elevation associated with the base flood plus any stage increases that result from designation of a floodway. 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 Zoning Administrator.
(2) Nonresidential principal structures. Nonresidential principal structures must meet one of the following construction methods:
(a) Elevation on fill. Structures may be elevated on fill, meeting the standards in this section. Fill for nonresidential structures is not required to be extended 15 feet beyond the outside limits of the structure.
(b) Dry floodproofing. Structures having watertight enclosed basements or spaces below the Regulatory Flood Protection Elevation (RFPE) must meet the following standards:
1. Walls must be substantially impermeable to the passage of water, with structural
components having the capacity of resisting hydrostatic and hydrodynamic loads and effects of buoyancy, at least up to the Regulatory Flood Protection Elevation (RFPE);
2. Must meet the standards of FEMA Technical Bulletin 3, as amended; and
3. A registered professional engineer or architect shall be required to certify that the design and methods of construction meet the standards detailed in this section.
(3) Accessory structures. All accessory structures must meet the following standards:
(a) Structures shall not be designed or used for human habitation.
(b) Structures will have a low flood damage potential.
(c) Structures with fewer than two rigid walls, such as carports, gazebos, and picnic pavilions, may be located at an elevation below the Regulatory Flood Protection Elevation.
(d) Structures with two or more rigid walls must meet one of the following construction methods:
1. Wet floodproofing. Structures may be floodproofed in a way to accommodate internal flooding. Such structures shall constitute a minimal investment not to exceed 576 square feet in size, one-story in height, and shall only be used for parking and storage. 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, and shall allow automatic entry and exit of flood waters without human intervention.
2. Elevation on fill. Structures may be elevated on fill, meeting the standards in this section. Fill is not required to be extended 15 feet beyond the outside limits of the structure for accessory structures.
3. Dry floodproofing. Structures may be dry floodproofed, or watertight, meeting the standards in division (B)(2) above.
(4) Any facilities used by employees or the general public must be designed with a flood warning system acceptable to the city that provides adequate time for evacuation, or be designed to ensure that within the area inundated during the base flood event, the depth (in feet) multiplied by the velocity (in feet per second) is less than four.
(C) Standards for interior ponding areas. In addition to the applicable standards detailed above, the following criteria apply to activities in the Interior Ponding Areas identified in § 153.03(C)(3).
(1) Compensatory storage requirement. Any fill placed in the Interior Ponding Areas must be offset with compensatory flood storage volume of equal or greater volume below the BFE. Compensatory storage must occur contiguous with the same impacted Interior Ponding Area. The excavated material removed to create the compensatory storage area must not be deposited elsewhere in the floodplain. Preparation and final grading must be consistent with the applicable flood fringe standards set forth in this section.
(2) Earthwork, grading, or construction in the Interior Ponding Areas cannot inhibit, reroute, or restrict runoff patterns, and must maintain adequate area for runoff to flow to the stormwater system.
(Ord. 151, 4th Series, passed 9-6-2022)