(A) Permitted uses. The following uses, subject to the standards set forth in division (B) below, are permitted uses if otherwise allowed in the underlying zoning district or any applicable overlay district:
(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) 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 lawns, gardens, parking areas, and play areas.
(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, and that the standards in division (D)(1), (3)(a) and (6), below, are met.
(B) Standards for floodway permitted uses.
(1) The use must have a low flood damage potential.
(2) With the exception of the uses listed in division (A)(5), the use must not obstruct flood flows or increase flood elevations and must not involve structures, fill, obstructions, excavations or storage of materials or equipment.
(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 § 154.095(D) of this subchapter and further subject to the standards set forth in division (D) below, if otherwise allowed in the underlying zoning district or any applicable overlay district.
(1) Structures accessory to the uses listed in division (A) above and the uses listed in division(C)(2) through (7) below.
(2) Extraction and storage of sand, gravel, and other materials.
(3) Marinas, boat rentals, docks, piers, wharves, and water control structures.
(4) Storage yards for equipment, machinery, or materials.
(5) Placement of fill or construction of fences that obstruct flood flows. Farm fences, as defined in § 154.087, are permitted uses.
(6) Travel-ready recreational vehicles meeting the exception standards in § 154.094(C).
(7) 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) All uses. A conditional use must not cause any increase in the stage of the 1% chance or regional flood or cause an increase in flood damages in the reach or reaches affected.
(2) Fill; 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) 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.
(c) 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.
(a) Accessory structures must not be designed for human habitation.
(b) Accessory structures, if permitted, must 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 must be constructed with the longitudinal axis parallel to the direction of flood flow; and
2. So far as practicable, structures must be placed approximately on the same flood flow lines as those of adjoining structures.
(c) Accessory structures must be elevated on fill or structurally dry floodproofed in accordance with the FP-1 or FP-2 floodproofing classifications in the state building code. All floodproofed accessory structures must meet the following additional standards:
1. The structure must be adequately anchored to prevent flotation, collapse or lateral movement and designed to equalize hydrostatic flood forces on exterior walls; and
2. Any mechanical and utility equipment in the structure must be elevated to or above the regulatory flood protection elevation or properly floodproofed.
(d) As an alternative, an accessory structure may be internally/wet floodproofed to the FP-3 or FP-4 floodproofing classifications in the state building code, provided the accessory structure constitutes a minimal investment and does not exceed 576 square feet in size. A detached garage may only be used for parking of vehicles and limited storage. All structures must meet the following standards:
1. To allow for the equalization of hydrostatic pressure, there must be a minimum of two “automatic” openings in the outside walls of the structure, with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding; and
2. 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.
(4) Structural works. 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) Levees, dikes, or floodwalls. 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.
(6) Floodway developments must not adversely affect the hydraulic capacity of the channel and adjoining floodplain of any tributary watercourse or drainage system.
(2004 Code, § 154.088) (Ord. 464, passed 1- -1996; Ord. 98-223, passed 5-12-1998; Ord. 14-0729, passed 6-10-2014)