A. Intent: The intent of this section is to minimize the risk of flood or water damage to structures within the city. As a result, no structure shall be built within a wetland, shall have a three foot (3') vertical separation from periodically saturated soils and shall have a three foot (3') vertical separation from the 100-year storm elevation (if known). For riparian lots, all dwellings shall have a three foot (3') vertical separation from the ordinary high water mark. In addition, no structure shall be built within a "floodway", "flood fringe" or general floodplain district as defined and enforced in title 12 of this code.
B. Definitions: All terms used herein shall be as defined in title 10 of this code or Minnesota rules section 7080 unless specifically defined below:
100-YEAR STORM WATER ELEVATION: The water surface elevation determined in a 100-year, twenty four (24) hour storm water analysis.
PERIODICALLY SATURATED SOIL: The highest elevation in the soil that is in a reduced chemical state due to soil pores filled or nearly filled with water causing anaerobic conditions. Periodically saturated soil is determined by the presence of redoximorphic features in conjunction with other established indicators as specified in part 7080.1720, subpart 5, items E and F, or determined by other scientifically established technical methods or empirical field measurements acceptable to the permitting authority in consultation with the commissioner.
VERTICAL SEPARATION: The vertical measurement of the periodically saturated soil, the 100-year storm water elevation or the ordinary high water mark and the bottom of the lowest floor of proposed structure to be constructed.
C. Enforcement: To ensure compliance with these requirements, no building permit for new construction or remodeling jobs that increase the footprint of a building shall be issued until the city building official is satisfied, in its sole discretion, that the structure meets all of the above requirements. To confirm these requirements, the city building official may require any or all of the following based upon the location and nature of the construction site:
1. Soil borings or a soil pit of the soil.
2. A certified wetland delineation as shown on a certificate of survey from a Minnesota licensed surveyor.
3. Ordinary high water mark as shown on a certificate of survey from a Minnesota licensed surveyor.
4. 100-year storm water elevation as determined in writing by a Minnesota licensed engineer after proper design and construction of said stormwater design.
D. Exception/Cup Required: An applicant may construct a nondwelling structure (which is not attached to a dwelling or is, in the sole determination of the city building official, sufficiently separated from a dwelling) as low as one foot (1') above the 100-year storm water elevation as long as they apply and receive a conditional use permit from the city. In considering said conditional use permit, the city shall review the effect of this lower elevation, if any, upon adjacent owners and any dwellings located or to be located on the subject site. Conditions shall require the applicant to design the structure to ensure that any flooding or excess water shall not overflow into adjacent properties or the city water or sewer utility systems. Conditions may also require other mitigation measures to control or eliminate mold, damage to materials or other health/safety reasons. (Ord. 2008-13, 11-18-2008)