This chapter’s protection standard is based on the flood insurance study for the city. If a base flood elevation is not available for a particular site, then the protection standard shall be according to the best existing data available in the Illinois State Water Survey’s Flood Plain Information Repository. When a party disagrees with the best available data, he or she may finance the detailed engineering study needed to replace existing data with better data and submit it to IDNR and FEMA for review and consideration prior to any development of the site.
(A) The base flood elevation for the floodplain in the city shall be as delineated on the base flood profiles in the flood insurance study of the city prepared by FEMA and dated November 1, 2019, and such amendments to such study and maps as may be prepared from time to time.
(B) The base flood elevation for the floodplain of those parts of unincorporated Cook County that are within the extraterritorial jurisdiction of the city or that may be annexed into the city shall be as delineated on the base flood profiles in the Flood Insurance Study of Cook County prepared by FEMA and dated November 1, 2019, and such amendments or revisions to such study and maps as may be prepared from time to time.
(C) The base flood elevation for each floodplain delineated as an “AH Zone” or “AO Zone” shall be that elevation (or depth) delineated on the flood insurance rate map of Cook County and listed in Appendix A of Ord. O-16-19, passed October 15, 2019.
(D) The BFE for each of the remaining floodplains delineated as an A Zone on the countywide FIRM of Cook County and listed in Appendix A of Ord. O-16-19, passed October 15, 2019, shall be according to the best existing data available from federal, state or other sources. Should no other data exist, an engineering study must be financed by the applicant to determine BFEs.
(1) When no BFE exists, the BFE for a riverine floodplain shall be determined from an accepted hydraulic model, based on current industry standards.
(2) The flood flows used in the hydraulic models shall be obtained from an accepted hydrologic model, based on current industry standards, or by techniques presented in various publications prepared by the United States Geological Survey for estimating peak flood discharges.
(Ord. 92-23, passed 6-16-92; amend. Ord. O-14-03, passed 2-18-03; amend. Ord. O-19-08, passed 8-5-08; amend. Ord. O-16-19, passed 10-15-19)
Penalty, see § 151.99