(A) Permitted uses in the floodplain. The following uses of land are permitted uses in the floodplain district:
(1) Any use of land which does not involve a structure, an addition to the outside dimensions to an existing structure or an obstruction to flood flows such as fill, excavation or storage of materials or equipment;
(2) Any use of land involving the construction of new structures, the placement or replacement of manufactured homes, the addition to the outside dimensions of an existing structure or obstructions such as fill or storage of materials or equipment, provided these activities are located in the flood fringe portion of the floodplain. These uses shall be subject to the development standards in division (B) below, and the floodplain evaluation criteria in division (C) below, for determining floodway and flood fringe boundaries; and
(3) Travel trailers and travel vehicles as regulated by § 151.22.
(B) Standards for floodplain permitted uses.
(1) Fill. Fill shall be properly compacted and the slopes shall be properly protected by the use of riprap, 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 incorporate 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.
(2) 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 or, if placed on fill, to the regulatory flood protection elevation.
(3) Use prohibited. No use shall be permitted which will adversely affect the capacity of the channels or floodways of any tributary to the main stream, or of any drainage ditch or any other drainage facility or system.
(4) Structures. All structures, including accessory structures, additions to existing structures and manufactured homes, shall be constructed on fill so that the basement floor, or first floor if there is no basement, is at or above the regulatory flood protection elevation. The finished fill elevation must be no lower than one foot below the regulatory flood protection elevation and shall extend at an elevation at least 15 feet beyond the limits of the structure constructed thereon.
(5) All uses. Uses that do not have vehicular access at or above an elevation not more than two feet below the regulatory flood protection elevation to lands outside of the floodplain shall not be permitted unless granted a variance by the Board of Adjustment. In granting a variance, the Board shall specify limitations on the period of use or occupancy of the use and only after determining that adequate flood warning time and local emergency response and recovery procedures exist.
(6) Commercial and manufacturing uses. 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 the facilities to be used by the employees or the 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.
(7) On-site sewage treatment and water supply systems. Where public utilities are not provided, on-site water supply systems must be designed to minimize or eliminate infiltration of flood waters into the systems; and new or replacement on-site sewage treatment systems must be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters and they shall not be subject to impairment or contamination during times of flooding. Any sewage treatment system designed in accordance with the state’s current state-wide standards for on-site sewage treatment systems shall be determined to be in compliance with this section.
(8) Manufactured homes. All manufactured homes must be securely anchored to an adequately anchored foundation system that resists flotation 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.
(C) Floodplain evaluation.
(1) Upon receipt of an application for a permit, manufactured home park development or subdivision approval within the floodplain district, the Zoning Officer shall require the applicant to furnish sufficient site development plans and a hydrologic/hydraulic analysis by a qualified engineer or hydrologist specifying the nature of the development and whether the proposed use is located in the floodway or flood fringe and the regulatory flood protection elevation for the site. Procedures consistent with Minn. Rules 1983, parts 6120.5600 (Technical Standards and Requirements for Floodplain Evaluation) and 6120.5700 (Minimum Floodplain Management Standards for Local Ordinances), shall be followed during the technical evaluation and review of the development proposal.
(2) The Zoning Officer shall submit one copy of all information required by division (C)(1) above, to the respective Department of Natural Resources’ Area Hydrologist for review and comment at least 20 days prior to the granting of a permit or manufactured home park development/subdivision approval by the city. The Zoning Officer shall notify the respective Department of Natural Resources’ Area Hydrologist within ten days after a permit or manufactured home park development/subdivision approval is granted.
(1989 Code, § 13.10)