42-234.4 Standards for Floodplains Without Established Base Flood Elevations

Within the Special Flood Hazard Areas designated as Approximate Zone A and established in §42-232.2 (Basis for Establishing the Special Flood Hazard Areas), where no BFE data has been provided by FEMA, the following provisions, in addition to §42-234.1 (General Standards), shall apply:

  1. No encroachments, including fill, new construction, substantial improvements or new development shall be permitted within a distance of 20 feet from each side of the stream measured from the top of the 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 one (1) of the following criteria set in priority order:
    1. When BFE data is available from other sources, such as Federal, State or other, all new construction and substantial improvements within such areas shall also comply with all applicable provisions of this subpart and shall be elevated or flood proofed in accordance with standards in this §42-234.1 (General Standards) and §42-234.2 (Specific Standards).
    2. When floodway or non-encroachment area data are available from a Federal, State, or other source, all new construction and substantial improvements within floodway and non-encroachment areas shall also comply with the requirements of §42-234.2 (Specific Standards) and §42-234.6 (Floodways and Non-Encroachment Areas).
    3. When a subdivision, manufactured home park or other development proposal is greater than five (5) acres or has more than 50 lots/manufactured home sites/spaces, BFE data shall be provided. Such BFE data shall be adopted by reference in accordance with §42-232.2 (Basis for Establishing the Special Flood Hazard Areas).
    4. When BFE data is not available from a Federal, State, or other source as outlined above, the reference level shall be elevated or flood proofed to or above the Regulatory Flood Protection Elevation as defined in Article XIV (Definitions).