(a) Standards. The standards for flood protection established in this article XIV are based on the flood insurance study for the village. 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 Floodplain Information Repository. When a party disagrees with the best available data, such party may finance the detailed engineering study needed to replace existing data with better data and submit it to OWR and FEMA.
(b) Base flood: Skokie River. The base flood evaluation for the SFHAs of the Skokie River shall be as delineated on the 100-year flood profiles in the countywide Flood Insurance Study for Cook County prepared by FEMA and dated August 19, 2008, and such amendments or revisions to such study and maps as may be prepared from time to time.
(c) Base flood: unincorporated property. The base flood elevation for the SFHAs of those part of unincorporated Cook County that are within the extraterritorial jurisdiction of the village or that may be annexed into the village shall be as delineated on the 100-year flood profiles in the countywide Flood Insurance Study for Cook County prepared by FEMA and dated August 19, 2008, and such amendments or revisions to such study and maps as may be prepared from time to time.
(d) Base flood: AH or AO Zones. The BFE for each floodplain delineated as an AH Zone or AO Zone shall be that elevation (or depth) indicated on the countywide FIRM of Cook County and dated August 19, 2008 and September 10, 2021, and such amendments or revisions to such study and maps as may be prepared from time to time. For any AH zone with an elevation specified in a table of still water elevations in the FIS, the BFE shall be the elevation specified in the table of still water elevations.
(e) Base flood: other zones. The BFE for each of the remaining floodplains delineated as an A Zone on the countywide FIRM of Cook County 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. 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.
(f) No base flood elevation. When no BFE exists, the BFE for a riverine floodplain shall be determined from an accepted hydraulic model, based on current industry standards. The flood flows used in the hydraulic models shall be obtained from a hydrologic model, such as HEC-I, TR-20 or HIP, or by techniques presented in various publications prepared by the United States Geological Survey for estimating peak flood discharges. Flood flows shall be based on anticipated future land use conditions in the watershed as determined from adopted local and regional land use plans. Along any watercourses draining more than one square mile, the above analyses shall be submitted to OWR for approval. Once approved, any such analysis must be submitted to the Illinois State Water Survey Floodplain Information Repository for filing.
(Ord. No. 2021-16-3512)