A. Designation of Critical Area. All development within special flood hazard areas in the City of Bellevue is subject to the terms of this section and other applicable regulations. Frequently flooded areas shall be the greatest area identified in this subsection. In no case shall the extent or flood depths of a frequently flooded area be less than those identified on the current Flood Insurance Rate Maps.
Frequently flooded areas shall include:
1. Land Subject to One-Hundred-Year Flood. The land in the floodplain subject to the flood having a one percent chance or greater of being equaled or exceeded in any given year as determined by customary methods of statistical analysis defined in the City of Bellevue Storm and Surface Water Engineering Standards, now or as hereafter amended. Also referred to as the 100-year flood.
2. Areas Identified on the Flood Insurance Rate Map(s). Those areas identified by the Federal Insurance Administrator in a scientific and engineering report entitled “The Flood Insurance Study (FIS) for King County, Washington, and Incorporated Areas,” dated August 19, 2020, with an accompanying Flood Insurance Rate Map(s) (FIRM(s)), dated August 19, 2020, and any revisions thereto. The FIS and accompanying FIRM(s) are hereby adopted by reference, declared part of this Part 20.25H LUC, and are available for public review at the City of Bellevue. The best available information for flood hazard area identification as outlined in subsection A.6 of this section shall be the basis for regulation until a new FIRM is issued that incorporates data utilized under subsection A.6 of this section.
4. Designation of Areas of Special Flood Hazard. Flood Insurance Rate Maps are to be used as a guide for the City of Bellevue, project applicants, and/or property owners to identify areas of special flood hazard. Flood Insurance Rate Maps may be continuously updated as areas are reexamined or new areas are identified. Newer and more restrictive information for flood hazard area identification shall be the basis for regulation.
5. Use of Additional Information. The Director may use additional flood information that is more restrictive or detailed than that provided in the Flood Insurance Study to designate frequently flooded areas, including data on channel migration, historical data, high water marks, photographs of past flooding, location of restrictive floodways, maps showing future build-out conditions, maps that show stream habitat areas, or similar information.
6. Flood Elevation Data. When base flood elevation data is not available (A and V zones), the Director shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state, or other source, in order to administer provisions for the frequently flooded areas. In areas of special flood hazard where the BFE has increased due to remapping efforts, the new BFE will establish the regulatory limit.