(A) No encroachments, including fill, new construction, substantial improvements or new development shall be permitted within a distance of 20 feet each side from top of bank or five times the width of the stream, whichever is greater, unless certification with supporting technical data by a registered professional engineer is provided demonstrating that such encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.
(B) The BFE used in determining the regulatory flood protection elevation shall be determined based on one of the following criteria set in priority order.
(1) If base flood elevation (BFE) data is available from other sources, all new construction and substantial improvements within such areas shall also comply with all applicable provisions of this chapter and shall be elevated or accordance with standards in § 154.25.
(2) All subdivision, manufactured home park and either development proposals located within special flood hazard areas shall provide base flood elevation (BFE) data if development is greater than five acres or has more than 50 lots manufactured home sites. Such base flood elevation (BFE) data shall be adopted by reference per § 154.06 to be utilized in implementing this chapter.
(3) When base flood elevation (BFE) data is not available from a federal, state or other source as outlined above, the reference level shall be elevated above the highest adjacent grade as required in the regulatory flood protection elevation definition.
(Ord. passed 11-7-2005)