PROJECT ALERT NOTICE (IL) More record flooding in IL

Date: Mon, 22 Apr 2013 15:12:08 EDT

Summary: Record flooding on the Illinois River

Heavy rainfall across Illinois resulted in record flooding in smaller streams (including many urban drainages in Chicago) late last week. All of that flow has now converged on the Illinois River, and the result is more record flooding on the mainstem of the Illinois. At least 10 USGS gages with records over 20 years have experienced new peaks-of-record. At least 26 gages experienced recurrence intervals of >100 yrs (that is, <1% chance AEP), and 30 streamgages are still at the National Weather Service “major” category in and around Illinois. Several levees have been overtopped, and more are expected to be overtopped as the flood moves down the Illinois River.

Six USGS crews (including 1 crew from MO WSC) are out across the Illinois making streamflow measurements at streamgages to ensure that accurate data are being provided to the National Weather Service and the Corps of Engineers for flood forecasts and to emergency management officials and the public so that timely decisions can be made to protect life and property. Efforts will continue throughout the week. We have been in close coordination with the Corps, the NWS, and our state water agency (IL DNR) using NWSChat. And we have been in frequent contact with the USGS National Flood Coordinator.

Sub-Region: Midwest; Region: Central United States