(1) No encroachments, including fill, new construction, substantial improvements or new development shall be permitted within a distance of twenty (20) feet each side from top of bank or five (5) 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.
(2) The BFE used in determining the regulatory flood protection elevation shall be determined based on the following criteria:
(a) When 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 floodproofed in accordance with standards in Article E, sections 9-6-41 and 9-6-42.
(b) When floodway data is available from a federal, state, or other source, all new construction and substantial improvements within floodway areas shall also comply with the requirements of Article 5, Sections B and F.
(c) All subdivision, manufactured home park and other development proposals shall provide base flood elevation (BFE) data if development is greater than five (5) acres or has more than fifty (50) lots/manufactured home sites. Such base flood elevation (BFE) data shall be adopted by reference in accordance with Article C, section 9-6-22 and utilized in implementing this chapter. However, this requirement may be waived if the development ensures that all building envelopes exclude any special flood hazard areas.
(d) 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 or floodproofed (nonresidential) to or above the regulatory flood protection elevation, as defined in Article 2. All other applicable provisions of Article 5, Section B shall also apply.
(Ord. of 11/4/02, No. 363-02; Ord. of 8/6/07, No. 1-08)