(A) Permitted uses. The following uses are permitted uses in the Floodway District; provided that, the use is also listed in the city code as a permitted or conditional use in the underlying zoning district. In the event that the use is permitted in the Floodway District, but is listed as a conditional use in the underlying zoning district, a conditional use permit is still required:
(1) General farming, pasture, grazing, outdoor plant nurseries, horticulture, truck farming, forestry, sod farming and wild crop harvesting;
(2) Industrial-commercial loading areas, parking areas and airport landing strips;
(3) Private and public golf courses, tennis courts, driving ranges, archery ranges, picnic grounds, boat launching ramps, swimming areas, parks, wildlife and nature preserves, game farms, fish hatcheries, shooting preserves, target ranges, trap and skeet ranges, hunting and fishing areas, and single or multiple purpose recreational trails; and
(4) Residential lawns, gardens, parking areas and play areas.
(B) Standards for floodway permitted uses.
(1) The use shall have a low flood damage potential.
(2) The use shall be permissible in the underlying zoning district.
(3) The use shall not obstruct flood flows or increase flood elevations and shall not involve structures, fill, obstructions, excavations or storage of materials or equipment.
(C) Conditional Uses. The following uses are conditional uses in the Floodway District; provided that, the use is also listed in the city code as a permitted or conditional use in the underlying zoning district. In the event that the use is conditional in the Floodway District, but is a permitted use in the underlying zoning district, a conditional use permit is still required:
(1) Structures accessory to the uses listed in division (A) above and the uses listed below;
(2) Extraction and storage of sand, gravel and other materials;
(3) Marinas, boat rentals, docks, piers, wharves and water control structures;
(4) Railroads, streets, bridges, utility transmission lines and pipelines;
(5) Storage yards for equipment, machinery or materials;
(6) Placement of fill or construction offenses;
(7) Recreational vehicles either on individual lots of record or in existing or new subdivisions or commercial or condominium type campgrounds, subject to the exemptions and provisions of § 160.42(C) of this chapter; and
(8) Structural works for flood control such as levees, dikes and floodwalls constructed to any height where the intent is to protect individual structures and levees or dikes where the intent is to protect agricultural crops for a frequency flood event equal to or less than the ten-year frequency flood event.
(D) Standards for floodway conditional uses.
(1) No structure (temporary or permanent), fill (including fill for roads and levees), deposit, obstruction, storage of materials or equipment, or other uses may be allowed as a conditional use that will cause any increase in the stage of the 100-year or regional flood or cause an increase in flood damages in the reach or reaches affected.
(2) All floodway conditional uses are subject to the procedures and standards contained in § 160.58 of this chapter.
(3) The conditional use shall be permissible in the underlying zoning district.
(4) (a) Fill, dredge spoil and all other similar materials deposited or stored in the floodplain shall be protected from erosion by vegetative cover, mulching, riprap or other acceptable method.
(b) Dredge spoil sites and sand and gravel operations shall not be allowed in the floodway unless a long-term site development plan is submitted which includes an erosion/sedimentation prevention element to the plan.
(c) As an alternative, and consistent with division (D)(4)(b) above, dredge spoil disposal and sand and gravel operations may allow temporary on-site storage of fill or other materials which would have caused an increase to the stage of the 100-year or regional flood but only after the city has received an appropriate plan which assures the removal of the materials from the floodway based upon the flood warning time available. The conditional use permit must be recorded with the property in the office of the County Recorder or County Registrar of Titles, as appropriate.
(5) (a) Accessory structures shall not be designed for human habitation.
(b) Accessory structures shall be permissible in the underlying zoning district.
(c) Accessory structures, if permitted, shall be constructed and placed on the building site so as to offer the minimum obstruction to the flow of flood waters.
1. Whenever possible, structures shall be constructed with the longitudinal axis parallel to the direction of flood flow; and
2. So far as practicable, structures shall be placed approximately on the same flood flow lines as those of adjoining structures.
(d) Accessory structures shall be elevated on fill or structurally dry flood-proofed in accordance with the FP-1 or FP-2 flood-proofing classifications in the State Building Code. As an alternative, an accessory structure may be flood-proofed to the FP-3 or FP-4 flood-proofing classification in the State Building Code; provided, the accessory structure constitutes a minimal investment, does not exceed 500 square feet in size at its largest projection, and for a detached garage, if permitted in the underlying zoning district, the detached garage is used solely for parking of vehicles and limited storage. All flood-proofed accessory structures must meet the following additional standards.
1. The structure must be adequately anchored to prevent flotation, collapse or lateral movement of the structure and shall be designed to equalize hydrostatic flood forces on exterior walls.
2. Any mechanical and utility equipment in a structure must be elevated to or above the regulatory flood protection elevation or properly flood-proofed.
3. To allow for the equalization of hydrostatic pressure, there must be a minimum of two “automatic” openings in the outside walls of the structure having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding. 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.
(6) (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 and in accordance with a plan approved by the city.
(7) Structural works for flood control that will change the course, current or cross section of protected wetlands or public waters shall be subject to the provisions of M.S. Chapter 103G, as it may be amended from time to time. City-wide structural works for flood control intended to remove areas from the regulatory floodplain shall not be allowed in the floodway.
(8) A levee, dike or floodwall constructed in the floodway shall not cause an increase to the 100-year or regional flood and the technical analysis must assume equal conveyance or storage loss on both sides of a stream.
(Prior Code, § 530.07) (Ord. 2012-05, passed 3-7-2012)