11-12-4: FLOODWAY DISTRICT (FW):
   A.   Permitted Uses:
      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.
      4.   Residential lawns, gardens, accessory 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:
      1.   Structures accessory to permitted uses listed above.
      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, other than fuel storage tanks.
      6.   Placement of fill or construction of fences.
      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 subsection 11-12-9C of this chapter.
      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 10-year frequency flood event.
   D.   Standards For Floodway Conditional Uses:
      1.   All Uses: 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.   Conditional Uses: All floodway conditional uses are subject to the procedures and standards contained in subsection 11-12-10D of this chapter.
      3.   Conditional Use Permissible: The conditional use shall be permissible in the underlying zoning district.
      4.   Fill:
         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 subsection D4b of this section, 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 in the office of the county recorder or county registrar of titles, as appropriate.
      5.   Accessory Structures:
         a.   Accessory structures shall not be designed for human habitation.
         b.   Accessory structures, if permitted, shall be constructed and placed on the building site so as to offer the minimum obstruction to the flow of floodwaters:
            (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.
         c.   Accessory structures shall be elevated on fill or structurally dry floodproofed in accordance with the FP-1 or FP-2 floodproofing classifications in the state building code. As an alternative, an accessory structure may be floodproofed to the FP-3 or FP-4 floodproofing classification in the state building code provided the accessory structure constitutes a minimal investment, does not exceed five hundred (500) square feet in size at its largest projection, and for a detached garage, the detached garage must be used solely for parking of vehicles and limited storage. All floodproofed 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 floodproofed; and
            (3)   To allow for the equalization of hydrostatic pressure, there must be a minimum of two (2) "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 (2) sides of the structure and the bottom of all openings must be no higher than one foot (1') 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.   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 and in accordance with a plan approved by the city council.
      7.   Structural Works: 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 Minnesota statutes, chapter 103G. Community wide structural works for flood control intended to remove areas from the regulatory floodplain shall not be allowed in the floodway.
      8.   Levee, Dike Or Floodwall In Floodway: 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. (Ord. 872, 2-3-2010)