Agenda - Council - 10/27/2015 - Laserfiche WebLink

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Ordinance Language (c) The plan may incorporate alternative procedures for removal of the material from the floodplain if adequate flood warning time exists. 5.45 Storage of materials and equipment below the regulatoryflood protection elevation must comply with an approved emergency plan providing for removal of such materials within the time available after a flood warning. 5.46 RESERVED FOR OPTIONAL ALTERNATIVE ELEVATION METHODS SECTION 6.0 GENERAL FLOODPLAIN DISTRICT (GF) 6.1 Permitted Uses: 6.11 The uses listed in Section 4.1 of this ordinance, Floodway District Permitted Uses, are permitted uses. 6.12 All other uses are subject to the floodway/flood fringe evaluation criteria specified in Section 6.2 below. Section 4.0 applies if the proposed use is determined to be in the Floodway District. Section 5.0 applies if the proposed use is determined to be in the Flood Fringe District. 6.2 Procedures for Floodway and Flood Fringe Determinations: 6.21 Upon receipt of an application for a permit or other approval within the General Floodplain District, the Zoning Administrator must obtain, review and reasonably utilize any regional flood elevation and floodway data available from a federal, state, or other source. 6.22 If regional flood elevation and floodway data are not readily available, the applicant must furnish additional information, as needed, to determine the regulatory flood protection elevation and whether the proposed use would fall within the Floodway or Flood Fringe District. Information must be consistent with accepted hydrological and hydraulic engineering standards and the standards in 6.23 below. 6.23 The determination of floodway and flood fringe must include the following components, as applicable: (a) Estimate the peak discharge of the regional (1% chance) 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 floodway necessary to convey or store the regional flood without increasing flood stages more than one-half (0.5) foot. A lesser stage increase than 0.5 foot is required if, as a result of the stage increase, increased flood damages would result. An equal degree of encroachment on both sides of the stream within July 2015 12 Commentary Alternative elevation methods such as the use of stilts, pilings, parallel walls, etc. may be appropriate in certain circumstances, provided that communities are able to provide a high level of monitoring and enforcement. Contact DNR floodplain staff for the applicable language. If the General Floodplain District (the A zone or the AE, AO orAH zones without a defined floodway) is not present within the community, delete the contents of this section and retitle it "Reserved for Future Use" (i.e., in case a future annexation adds an A zone). State and federal rules establish standards for this determination but do not specify a procedure to be followed. (However, the community is required under 44 CFR 60.3(b)(4) to "obtain, review and reasonably utilize" base flood elevation and floodway data.) The procedure shown here is one that DNR suggests that communities follow. DNR Floodplain Program staff can assist communities in obtaining relevant data and completing the determination. Commented [TG33]: 117-185