Big Ten Academic Alliance Geospatial Discovery Portal

Big Ten Academic Alliance Geoportal

One-Hundred and Five-Hundred Year Floodzones for Unincorporated Areas: Illinois, 2006

This feature class was quickly assembled from old Arc/Info coverages to produce a general graphic image and has not reviewed or quality-controlled in any way and is not supported. This is a statewide polygon feature class of 100 year and 500 year flood zones as of 1986 for the unincorporated areas of Illinois as indicated on Federal Emergency Management Agency (FEMA) National Flood Insurance Program (FIRM) maps and Flood Hazard Boundary maps. The statewide data layer was created by appending data from 102 county-wide Arc/Info coverages originally released on Illinois DNR GIS data CDs dated 1996. The data were digitized from paper maps. RMS values were not more than twenty feet in the original digitizing process. Mapscale: 1:6000 to 1:24,000.
Illinois Geospatial Data Clearinghouse
Illinois, United States
Inland Waters, Wetlands, Floodzones, and Hydrology
Contributed by:
More details at