(A) The City Council officially recognizes the beneficial functions the floodplain serves in storage and transportation of water during floods. Placement of fill in the floodplain area is discouraged and should be minimized. No fill shall be permitted in the floodway.
(B) All fill placed in other floodplain areas shall meet or exceed the following standards:
(1) Fill shall be used only to the extent to which it does not adversely affect adjacent properties. The city may require the applicant to demonstrate, through engineering reports, that proposed fill would not adversely affect adjacent properties. When required, hydrologic and hydraulic analyses shall be undertaken only by professional engineers who shall certify that the technical methods used correctly reflect currently accepted technical concepts. The resultant study shall include a cover letter, signed, and sealed by the responsible professional, providing a statement of findings in basic terms. In addition, studies, analyses, computations, and the like shall be submitted in sufficient detail to allow a thorough technical review by the city. During permit review, the community shall consider the following issues that have the potential to cause adverse impact to adjacent properties:
(a) Unacceptable increases in flood heights;
(b) Blocking drainage from adjacent property;
(c) Deflection of flood waters onto adjacent existing structures;
(d) Increases to stream velocity initiating or exacerbating erosion problems; and
(e) Other unique site conditions may be considered when determining whether fill will cause adverse impact to adjacent property including, but not limited to, subsidence areas, karst topography, stream blockages, and steep topography adjacent to the channel.
(2) Fill shall be used only to the extent to which it does not adversely affect the capacity of channels or floodways of any tributary to the main stream, drainage ditch, or any other drainage facility or system;
(3) Filled site must be contoured to drain properly (to avoid ponding);
(4) Fill shall extend beyond a structure for a sufficient distance to provide acceptable access. For residential structures, fill shall extend laterally 15 feet beyond the building line from all points before the start of sloping required in following section. For nonresidential structures, fill shall be placed to provide access acceptable for intended use;
(5) At grade access, with fill extending laterally 15 feet beyond the building line, shall be provided to a minimum of 25% of the perimeter of a nonresidential structure;
(6) Fill shall consist of soil or rock material only. Sanitary landfills shall not be permitted; no trash or woody debris shall be buried on site;
(7) Fill material shall be compacted to provide the necessary stability and resistance to erosion, scouring or settling. Fill compaction standards must be appropriate to proposed post fill use, particular attention is necessary when fill is being used to elevate a structure;
(8) Fill slopes shall be no steeper than one vertical on two horizontal, unless substantiating data justifying steeper slopes are submitted to and approved by the Floodplain Administrator;
(9) Fill site and fill must be protected from erosion;
(10) All applicants placing fill in a mapped flood hazard area must obtain a conditional letter of map revision (CLOMR) from FEMA when directed to do so by the Floodplain Administrator before a permit can be issued. After fill is finished, the applicant must convert the CLOMR to a letter of map revision based on fill (LOMR-F) before a certificate of compliance can be issued; and
(11) The applicant must submit any maps, computations, or other material required by the Federal Emergency Management Agency (FEMA) to revise the Flood Insurance Study and/or Flood Insurance Rate Maps, when notified by the Floodplain Administrator, and must pay any fees or other costs assessed by FEMA for this purpose.
(Ord. passed 5-4-1992; Ord. passed 2-8-2010)