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The County of DuPage
Wheaton, Illinois

County Mapping Update Overview

In 2008, DuPage County Stormwater Management received a $2,050,000.00 grant from the Federal Emergency Management Agency (FEMA) to restudy and remap the floodplains for 24 watersheds in DuPage County.  In cooperation with the Illinois State Water Survey (ISWS), this project will result in a new Countywide floodplain map updating the current FEMA Digital Flood Insurance Rate Map (DFIRM) map dated December 16, 2004.  

This countywide project incorporated new flood hazard information in the following watersheds: 

  • Salt Creek Mainstem and its tributaries that include Spring Brook, Devon Avenue, Westwood Creek, Ginger Creek, Sugar Creek, Oak Brook Tributary and Bronswood Tributary
  • East Branch DuPage River Mainstem and its tributaries that include Swift Meadows/Army Trail Road, Armitage Creek, Glencrest Creek, Tributary No. 2, Rott Creek, Lacey Creek, Prentiss Creek, St. Joseph Creek, Crabtree Creek and Willoway Brook
  • Steeple Run Tributary, Spring Brook No. 1
  • Sawmill Creek, Wards Creek  

The new study information has resulted in new and modified: base flood elevations, Special Flood Hazard Area (SFHA) boundaries, floodway boundaries, and food insurance zone designations.  The revision also incorporated non-revised flood hazard information from effective FIS reports, FIRMs and Flood Boundary and Floodway Maps as appropriate for the remaining watersheds in DuPage County.  Fifty-six Letters of Map Revision (LOMR) and one multi-lot Letter of Map Amendment (LOMA) were also incorporated.