Editor's note(s)—Ord. No. 636, § 2, adopted Dec. 10, 2018, amended art. V in its entirety to read as herein set out. Former art. V, §§ 20-326—20-380, pertained to similar subject matter, and derived from: Ord. No. 80, Art. V, adopted Dec. 15, 1986; and Ord. No. 377, §§ 29, and 31—34, adopted May 24, 2004.
Sec 20-351 Conditional Use Permits
The following open space uses require accessory structures or fill or storage of materials or equipment. These uses may be permitted in the Floodway District only after the issuance of a conditional use permit as provided in section 20-387:
- Structures accessory to primary uses listed in subsections 20-348(a)(1)—(3), provided that:
- Structures are not intended for human habitation.
- Structures will have a low flood damage potential.
- Structures will be constructed and placed so as to offer a minimal obstruction to the flow of floodwaters.
- Structures must be elevated on fill, open sided or structurally dry floodproofed and watertight to the regulatory flood protection elevation. Certifications consistent with subsection 20-385(c) shall be required.
- Structures will 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.
- Placement of fill, provided:
- Any fill deposited in the floodway shall be no more than the minimum necessary for use. Generally, fill shall be limited to that needed to grade or landscape for that use and shall not in any way obstruct the flow of floodwaters, cause an increase in flood damages, or increase flood elevations in areas where a floodway has been established, as certified by a registered professional engineer.
- Spoil from dredging or sand and gravel operations shall not be deposited in the floodway unless it can be done in accordance with paragraph (2)a, above.
- 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.
- Storage of materials and equipment, provided:
- 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.
- Storage of other materials or equipment may be allowed only be allowed if the City of Chanhassen has approved a plan that assures removal of the materials from the floodway based upon the flood warning time available.
- Storage of other materials or equipment 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.
- A levee, dike or floodwall, provided:
- It must not cause an increase to the one percent chance or regional flood. The technical analysis must assume equal conveyance or storage loss on both sides of a stream.
- It 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.
- 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.
(Ord. No. 636, § 2, 12-10-18)
State law reference(s)—Conditional uses, M.S. § 462.3595.
Sec 20-368 Conditional Uses
The following uses may be permitted in the Flood Fringe District only after the issuance of a conditional use permit as provided in section 20-387:
- The placement of floodproofed nonresidential basements below the regulatory flood protection elevation, provided:
- The standards for permitted uses in the flood fringe listed in section 20-367 are met.
- All areas of nonresidential structures, including basements to be placed below the regulatory flood protection elevation, must be structurally dry floodproofed, which requires making the structure watertight with the walls substantially impermeable to the passage of water and with structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. A floodproofing certification consistent with subsection 20-385(c) shall be required.
- Residential basements are not allowed below the regulatory flood protection elevation.
(Ord. No. 636, § 2, 12-10-18)
State law reference(s)—Conditional uses, M.S. § 462.3595.
Sec 20-379 Subdivisions
In addition to the standards contained in chapter 18, subdivision of lands within the Floodplain Districts must meet the standards enumerated in this section. Manufactured home parks and recreational vehicle parks or campgrounds are considered subdivisions under this division.
- All lots within the Floodplain Districts must be able to contain a building site outside of the Floodway District at or above the regulatory flood protection elevation.
- All subdivisions must have road access both to the subdivision and to the individual building sites no lower than two feet below the regulatory flood protection elevation, unless a flood warning emergency plan for the safe evacuation of all vehicles and people during the regional (one percent chance) flood has been approved by the City of Chanhassen. The plan must be prepared by a registered engineer or other qualified individual, and must demonstrate that adequate time and personnel exist to carry out the evacuation.
- For all subdivisions in the floodplain, the Floodway and Flood Fringe District boundaries, the regulatory flood protection elevation and the required elevation of all access roads must be clearly labeled on all required subdivision drawings and platting documents.
- In the General Floodplain District, applicants must provide the information required in division 4 of this article to determine the regional flood elevation, the Floodway and Flood Fringe District boundaries and the regulatory flood protection elevation for the subdivision site.
- Subdivision proposals must be reviewed to assure that:
- All such proposals are consistent with the need to minimize flood damage within the flood-prone area;
- All public utilities and facilities, such as sewer, gas, electrical, and water systems are located and constructed to minimize or eliminate flood damage; and
- Adequate drainage is provided to reduce exposure of flood hazard.
(Ord. No. 636, § 2, 12-10-18)
Sec 20-380 Public Utilities
Public utilities: All public utilities and facilities such as gas, electrical, sewer, and water supply systems to be located in the floodplain must be floodproofed in accordance with the state building code or elevated to the regulatory flood protection elevation.
(Ord. No. 636, § 2, 12-10-18)
Sec 20-381 Public Transportation Facilities
Public transportation facilities: Railroad tracks, roads, and bridges to be located within the floodplain must comply with divisions 2 and 3 of this article. These transportation facilities must be elevated to the regulatory flood protection elevation where failure or interruption of these facilities would result in danger to the public health or safety or where such facilities are essential to the orderly functioning of the area. Minor or auxiliary roads or railroads may be constructed at a lower elevation where failure or interruption of transportation services would not endanger the public health or safety.
(Ord. No. 636, § 2, 12-10-18)
Sec 20-384 Recreational Vehicles
Recreational vehicles: New recreational vehicle parks or campgrounds and expansions to existing recreational vehicle parks or campgrounds are prohibited in any Floodplain District. Recreational vehicles placed in existing recreational vehicle parks, campgrounds or lots of record in the floodplain must either:
- Meet the requirements for manufactured homes in subsection 20-383(a); or
- Be travel ready, meeting the following criteria:
- The vehicle must have a current license required for highway use.
- The vehicle must be highway ready, meaning on wheels or the internal jacking system, attached to the site only by quick-disconnect type utilities commonly used in campgrounds and recreational vehicle parks.
- No permanent structural type additions may be attached to the vehicle.
- Accessory structures may be permitted in the Flood Fringe District, provided that they constitute a minimal investment, do not hinder the removal of the vehicle should flooding occur, and meet the standards outlined in subsections 20-329(a) and 20-367(b).
(Ord. No. 636, § 2, 12-10-18)
Sec 20-386 Variances
Unless otherwise stated a variance request from the provisions of this article will be processed and reviewed in accordance with applicable state statutes and chapter 20, article II of the City Code. Additional variance requirements within the Floodplain Districts shall be as follows:
- Adherence to state floodplain management standards. A variance must not allow a use that is not allowed in that district, permit a lower degree of flood protection than the regulatory flood protection elevation for the particular area, or permit standards lower than those required by state law.
- Additional variance criteria. The following additional variance criteria of the Federal Emergency Management Agency must be satisfied:
- Variances must not be issued by a community within any designated regulatory floodway if any increase in flood levels during the base flood discharge would result.
- Variances may only be issued by a community upon: (i) a showing of good and sufficient cause, (ii) a determination that failure to grant the variance would result in exceptional hardship to the applicant, and (iii) a determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances.
- Variances may only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
- Flood insurance notice. The zoning administrator must notify the applicant for a variance that: 1) the issuance of a variance to construct a structure below the base flood level will result in increased premium rates for flood insurance up to amounts as high as $25.00 for $100.00 of insurance coverage; and 2) such construction below the base or regional flood level increases risks to life and property. Such notification must be maintained with a record of all variance actions.
- General considerations. The community may consider the following factors in granting variances and imposing conditions on variances and conditional uses in floodplains:
- The danger that materials may be swept onto other lands or downstream to the injury of others.
- The availability of viable alternative locations for the proposed use that are not subject to flooding.
- The expected heights, velocity, duration, rate of rise and sediment transport of the floodwaters expected at the site.
- Submittal of hearing notices to the department of natural resources (DNR). The zoning administrator must submit hearing notices for proposed variances to the DNR sufficiently in advance to provide at least ten days' notice of the hearing. The notice may be sent by electronic mail or U.S. mail to the respective DNR area hydrologist.
- Submittal of final decisions to the DNR. A copy of all decisions granting variances must be forwarded to the DNR within ten days of such action. The notice may be sent by electronic mail or U.S. mail to the respective DNR area hydrologist.
- Recordkeeping. The zoning administrator must maintain a record of all variance actions, including justification for their issuance, and must report such variances in an annual or biennial report to the administrator of the National Flood Insurance Program, when requested by the Federal Emergency Management Agency.
(Ord. No. 636, § 2, 12-10-18)
Sec 20-387 Conditional Uses
Unless otherwise stated an application for a conditional use permit under the provisions of this article will be processed and reviewed in accordance with chapter 20, article IV of the City Code. Additional requirements for conditional uses within the Floodplain Districts shall be as follows:
- Conditions attached to conditional use permits. In addition to the standards identified in sections 20-351 and 20-368, the City of Chanhassen may attach such conditions to the granting of conditional use permits as it deems necessary to fulfill the purposes of this article. Such conditions may include, but are not limited to, the following:
- Limitations on period of use, occupancy, and operation.
- Imposition of operational controls, sureties, and deed restrictions.
- Requirements for construction of channel modifications, compensatory storage, dikes, levees, and other protective measures.
- Submittal of hearing notices to the department of natural resources (DNR). The zoning administrator must submit hearing notices for proposed conditional uses to the DNR sufficiently in advance to provide at least ten days' notice of the hearing. The notice may be sent by electronic mail or U.S. mail to the respective DNR area hydrologist.
- Submittal of final decisions to the DNR. A copy of all decisions granting conditional uses must be forwarded to the DNR within ten days of such action. The notice may be sent by electronic mail or U.S. mail to the respective DNR area hydrologist.
(Ord. No. 636, § 2, 12-10-18)
Sec 20-388 Nonconformities
Continuance of nonconformities: A use, structure, or occupancy of land which was lawful before the passage or amendment of this article but which is not in conformity with the provisions of this article may be continued subject to the following conditions. Historic structures, are subject to the provisions of this section.
- A nonconforming use, structure, or occupancy must not be expanded, changed, enlarged, or altered in a way that increases its flood damage potential or degree of obstruction to flood flows except as provided in subsection (b) below. Expansion or enlargement of uses, structures or occupancies within the Floodway District is prohibited.
- Any addition or structural alteration to a nonconforming structure or nonconforming use that would result in increasing its flood damage potential must be protected to the regulatory flood protection elevation in accordance with any of the elevation on fill or floodproofing techniques (i.e., FP1 thru FP4 floodproofing classifications) allowable in the state building code, except as further restricted in subsection (d) below.
- If any nonconforming use, or any use of a nonconforming structure, is discontinued for more than one year, any future use of the premises must conform to this article.
- If any structure experiences a substantial improvement as defined in this article, then the entire structure must meet the standards of division 2 or division 3 of this article for new structures, depending upon whether the structure is in the Floodway or Flood Fringe District, respectively.
- If any nonconformity is substantially damaged, as defined in this article, it may not be reconstructed except in conformity with the provisions of this article. The applicable provisions for establishing new uses or new structures in division 2 or division 3 will apply depending upon whether the use or structure is in the Floodway or Flood Fringe Districts, respectively.
- If any nonconforming use or structure experiences a repetitive loss, it must not be reconstructed except in conformity with the provisions of this article.
(Ord. No. 636, § 2, 12-10-18)