3.21.3 Base Flood Elevations
A. Basis for Determination in Mapped Areas
Base flood elevations shall be based upon the Flood Insurance Rate studies described in paragraph 8.4.2, Applicability, when such studies define a base flood elevation.
B. Development, including the construction of structures that only require building permits and land disturbing activity within Special Flood Hazard Areas or Future Conditions Flood Hazard Areas, as identified by the Federal Emergency Management Agency in the most current Flood Insurance Rate Studies, which are hereby adopted by reference and declared to be a part of this section, shall be prohibited unless carried out pursuant to the general standards in paragraph 8.4.3, Standards, or expressly authorized pursuant to paragraph 8.4.4, Development in Special Flood Hazard Areas and Future Conditions Flood Hazard Areas.
C. When Base Flood has not been Determined
1. When base flood elevations have not been determined, the Inspections Director, or designee, acting as the Floodplain Administrator, may require FEMA accepted hydrologic and hydraulic engineering studies, or may obtain, review, and reasonably utilize any base flood elevation data and floodway or non-encroachment area data available from a Federal, State, or other source in determining the appropriate base flood elevation.
2. On small streams where no base flood data has been provided, no encroachments, including fill, new construction, substantial improvements or new development, shall be permitted within the setbacks established in Sec. 8.5, Riparian Buffer Protection Standards, or Sec. 8.7, Watershed Protection Overlay Standards, or 20 feet each side from top of bank, or five times the width of the stream, whichever is greatest.