Water Resources of the United States
Date: Tue, 20 Feb 2018 15:16:13 EST
Summary: Moderate to major flooding is forecasted the​ northern half of ​Illinois due to 3 inches of rain falling since last night, and an additional 1-2 inches is expected to continue through mid-day tomorrow.
Since last evening, 1-3 inches of rainfall has fallen throughout the ​northern half of ​Illinois. ​Much of this area already had over 6 inches of snow on the ground, and a frost layer that is inhibiting infiltration. The National Weather Service (NWS) predicts an additional 1-2 inches to fall over the next 24 hours​.
The ​upper ​​Illinois River is currently ​projected by​ the NWS ​to reach the Major​ ​F​looding category. ​Several other smaller rivers​ (Fox, DuPage, Des Plaines, Kankakee)​ are likely to go into the NWS minor to moderate flooding category between ​now and the weekend.
Seven crews of ​Technicians​ from DeKalb and Urbana, Illinois, are deployed today. All crews are concentrating on swollen smaller streams today as most major streams are not expected to crest until ​Wednesday or later.
USGS has been in contact with ​the NWS ​and U.S. Army Corps of Engineers regarding ​streamgage observations and forecasts.
USGS WaterWatch flood table for Illinois
USGS WaterWatch flood map for Illinois