Subd. 1. Permitted uses. The following uses, subject to the standards set forth in § 1101.04 Subd. 2., are permitted uses if otherwise allowed in the underlying zoning district or any applicable overlay district:
a. 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, fishing areas, and single or multiple purpose recreational trails.
b. Residential lawns, gardens, parking areas, and play areas.
c. 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.
Subd. 2. Standards for floodway permitted uses.
a. The use must have a low flood damage potential.
b. The use must not obstruct flood flows or cause any increase in flood elevations and must not involve structures, obstructions, or storage of materials or equipment.
c. 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.
Subd. 3. Conditional uses. The following uses may be allowed as conditional uses following the standards and procedures set forth in § 1101.10 Subd.4. of this chapter and further subject to the standards set forth in § 1101.04 Subd. 4., if otherwise allowed in the underlying zoning district or any applicable overlay district.
a. Structures accessory to the uses listed in §§ 1101.04 Subd. 1. a. through c. above and the uses listed in b. through c. below.
b. Extraction and storage of sand, gravel, and other materials.
c. Marinas, boat rentals, docks, piers, wharves, and water control structures.
d. Storage yards for equipment, machinery, or materials.
e. Placement of fill or construction of fences that obstruct flood flows.
f. General farming, pasture, grazing, outdoor plant nurseries, horticulture, truck farming, forestry, sod farming, and wild crop harvesting.
Subd. 4. Standards for floodway conditional uses.
a. 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.
b. Fill; storage of materials and equipment.
(1) 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.
(2) 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.
(3) 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.
c. Accessory structures. Accessory structures, as identified in § 1101.04 Subd. 3.a., may be permitted, provided that:
(1) Structures are not intended for human habitation;
(2) Structures will have a low flood damage potential;
(3) Structures will be constructed and placed so as to offer a minimal obstruction to the flow of flood waters;
(4) Service utilities, such as electrical and heating equipment, within these structures must be elevated to or above the regulatory flood protection elevation or properly floodproofed; and
(5) Structures must be elevated on fill or structurally dry floodproofed in accordance with the FP1 or FP2 floodproofing classifications in the State Building Code. All floodproofed structures must be adequately anchored to prevent flotation, collapse or lateral movement and designed to equalize hydrostatic flood forces on exterior walls.
(6) As an alternative, an accessory structure may be internally/wet floodproofed to the FP3 or FP4 floodproofing classifications in the State Building Code, provided the accessory structure constitutes a minimal investment and does not exceed 576 square feet in size. Designs for meeting this requirement must either be certified by a registered professional engineer or meet or exceed the following criteria:
(a) 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
(b) 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.
d. 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.
e. 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.
f. Floodway developments must not adversely affect the hydraulic capacity of the channel and adjoining floodplain of any tributary watercourse or drainage system.
(Ord. 534, passed 10-24-2016)