04/06/2009 Council Packet - Laserfiche WebLink

Home Search

• • • Flood Plain Management 10. The safety of access to the property in times of flood for ordinary and emergency vehicles; 11. The expected heights, velocity, duration, rate of rise, and sediment transport of the floodwaters expected at the site; and 12. Any other factors which are relevant to the purpose of this chapter. (f) Determination of flood hazards. 1. Upon receipt of an application for a conditional use permit for a use within the Flood Plain Overlay District where the regulatory flood protection elevation is unknown, the applicant shall be required to furnish the following information as is deemed necessary by the Zoning Administrator for the determination of the regulatory flood protection elevation. a. A typical 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. b. Plan (surface view) showing elevations or contours of the ground; pertinent structures, fill or storage elevations; size, location and spatial arrangement of all proposed and existing structures on the site; location and elevation of streets; photographs showing existing land uses and vegetation upstream and downstream; and soil type. c. 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. 2. One copy of the above information shall be transmitted to a designated engineer or other expert person or agency for technical assistance in determining whether the proposed use adversely affects the capacity of the flood plain and to determine the regulatory flood protection elevation. Procedures consistent with Minnesota Regulations NR 86 -87 shall be followed in this expert evaluation. The designated engineer or expert shall: a. Estimate the peak discharge of the regional flood. b. Calculate the water surface profile of the regional flood based upon a hydraulic analysis of the stream channel and overbank areas. c. Compute the area necessary to convey the regional flood without increasing flood stages more than 0.5 feet. An equal degree of encroachment on both sides of the stream within the reach shall be assumed in computing the area of the regional flood. 3. Based upon the technical evaluation of the designated engineer or expert, the City Council shall determine whether the proposed use adversely affects the capacity of the flood plain or the regional flood protection elevation at the site.