§ 151.64  FLOODWAY DISTRICT (FW).
   (A)   Permitted uses.  The following uses, subject to the standards set forth in division (B) of this section, are permitted uses if otherwise allowed in the underlying zoning district or any applicable overlay district:
      (1)   General farming, pasture, grazing, farm fences, outdoor plant nurseries, horticulture, forestry, sod farming and wild crop harvesting;
      (2)   Industrial-commercial loading areas, parking areas and airport landing strips;
      (3)   Open space uses, including but not limited to 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, hunting and fishing areas, and single or multiple purpose recreational trails;
      (4)   Residential yards, lawns, gardens, parking areas and play areas; and
      (5)   Railroads, streets, bridges, utility transmission lines and pipelines, provided that the Department of Natural Resources’ Area Hydrologist is notified at least ten days prior to issuance of any permit.
   (B)   Standards for floodway permitted uses.
      (1)   The use must have a low flood damage potential.
      (2)   The use must not involve structures or obstruct flood flows. The use must not cause any increase in flood damages, nor any increase in flood elevations in areas where a floodway has been established, as certified by a registered professional engineer.
      (3)   Any facility that will be 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.
   (C)   Conditional uses.  The following uses may be allowed as conditional uses following the standards and procedures set forth in § 151.73 of this subchapter and further subject to the standards set forth in division (D) of this section, if otherwise allowed in the underlying zoning district.
      (1)   Structures accessory to primary uses listed in division (A)(1) through (3) above and primary uses listed in subsections (2) and (3) below;
      (2)   Grading, extraction, fill and storage of soil, sand, gravel and other materials;
      (3)   Marinas, boat rentals, permanent docks, piers, wharves, water control structures and navigational facilities;
      (4)   Storage yards for equipment, machinery or materials;
      (5)   Fences that have the potential to obstruct flood flows; and
      (6)   Levees or dikes intended 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)   A conditional use must not cause any increase in flood damages, nor any increase in flood elevations in areas where a floodway has been established, as certified by a registered professional engineer.
      (2)   (a)   Fill, dredge spoil, and other similar materials deposited or stored in the floodplain must be protected from erosion by vegetative cover, mulching, riprap or other acceptable method. Permanent sand and gravel operations and similar uses must be covered by a long-term site development plan.
         (b)   Temporary placement of fill, other materials or equipment which would cause an increase to the stage of the 1% chance or regional flood may only be allowed if the City Council has approved a plan that assures removal of the materials from the floodway based upon the flood warning time available. 
      (3)   Accessory structures, as identified in division (C)(1) of this section, may be permitted, provided that:
         (a)   Structures are not intended for human habitation;
         (b)   Structures will have a low flood damage potential;
         (c)   Structures will be constructed and placed so as to offer a minimal obstruction to the flow of flood waters;
         (d)    Structures must be elevated on fill or structurally dry floodproofed and watertight to the regulatory flood protection elevation. Certifications consistent with § 151.71(B) of this subchapter shall be required; and
         (e)   As an alternative, an accessory structure may be floodproofed in a way to accommodate internal flooding. 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, have a 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 floodwaters without human intervention. A floodproofing certification consistent with § 151.71(B) of this subchapter shall be required.
      (4)   Structural works for flood control that will change the course, current or cross section of protected wetlands or public waters are subject to the provisions of M.S. § 103G.245, as it may be amended from time to time. 
      (5)   A levee, dike or floodwall constructed in the floodway must not cause an increase to the 1% chance or regional flood. The technical analysis must assume equal conveyance or storage loss on both sides of a stream.
(Ord. 10-18-01, passed - -2018)