(A) Upon receipt of an application for a conditional use permit for a use within the Le Sueur Creek District, the applicant shall be required to furnish such of the following information as is deemed necessary by the Zoning Administrator for the determination of the regulatory flood protection elevation and whether the proposed use is within the Floodway or Flood Fringe District.
(1) A typical valley cross-section showing the channel of the stream, elevation of land areas adjoining each side of the channel, cross-sectional areas to be occupied by the proposed development, and high water information.
(2) Plan (surface view) showing elevations or contours of the ground; pertinent structure, fill, or storage elevations; size, location, and spatial arrangement of all proposed and existing structures on the site; location and elevations of streets; photographs showing existing land uses and vegetation upstream and downstream; and soil type.
(3) Profile showing the slope of the bottom of the channel or flow line of the stream for at least 500 feet in either direction from the proposed development.
(B) The applicant shall be responsible for submitting one copy of the above information to a designated engineer or other expert person or agency for technical assistance in determining whether the proposed use is in the Floodway or Flood Fringe District and to determine the regulatory flood protection elevation. Procedures consistent with Minn. Regs. 1983, Parts 6120.5000 -6120.6200, as they may be amended from time to time, shall be followed in this expert evaluation. The designated engineer or expert is strongly encouraged to discuss the proposed technical evaluation methodology with the respective Department of Natural Resources' Area Hydrologist prior to commencing the analysis. The designated engineer or expert shall:
(1) Estimate the peak discharge of the regional flood.
(2) Calculate the water surface profile of the regional flood based upon a hydraulic analysis of the stream channel and overbank areas.
(3) Compute the floodway necessary to convey or store the regional flood without increasing flood stages more than one-half foot. A lesser stage increase than one-half foot shall be required if, as a result of the additional stage increase, increased flood damages would result. An equal degree of encroachment on both sides of the stream within the reach shall be assumed in computing floodway boundaries.
(C) The Zoning Administrator shall present the technical evaluation and findings of the designated engineer or expert to the city. The city must formally accept the technical evaluation and the recommended Floodway and/or Flood Fringe District boundary or deny the permit application. The city, prior to official action, may submit the application and all supporting data and analyses to the Federal Emergency Management Agency, the Department of Natural Resources or the Planning Commission for review and comment. Once the floodway and flood fringe boundaries have been determined, the city shall refer the matter back to the Zoning Administrator who shall process the permit application consistent with the applicable provisions of §§ 151.050 through 151.053 and 151.070 through 151.074.
(Ord. 406, passed 11-27-1989)