USGS - science for a changing world

Illinois Water Science Center

Flooding river


Water Science Center


USGS Water Science Centers are located in each state.

There is a USGS Water Science Center office in each State. Washington Oregon California Idaho Nevada Montana Wyoming Utah Colorado Arizona New Mexico North Dakota South Dakota Nebraska Kansas Oklahoma Texas Minnesota Iowa Missouri Arkansas Louisiana Wisconsin Illinois Mississippi Michigan Indiana Ohio Kentucky Tennessee Alabama Pennsylvania West Virginia Georgia Florida Caribbean Alaska Hawaii New York Vermont New Hampshire Maine Massachusetts South Carolina North Carolina Rhode Island Virginia Connecticut New Jersey Maryland-Delaware-D.C.

Illinois Flooding Resources

Live WaterWatch

live water data at

USGS National Water Watch

USGS Illinois Flood News

USGS Measures Record Flooding in Illinois

April 23rd 2013

Flooded river from the 2013 Flood.


"USGS streamgage data are absolutely critical to our ability to forecast timing and magnitude of flood peaks. Without USGS data, our ability to issue accurate flood forecasts would be seriously jeopardized."

William Morris

Service Hydrologist

NOAA's National Weather Service, Chicago

Live Updates

be the first to know about a flood in your area

tweet us at USGS_IL hashtag flood

iphone graphic


The WaterAlert service sends e-mail or text (SMS) messages when certain parameters including water levels, as measured by a USGS real-time data collection station, exceed user definable thresholds.


On-demand, current conditions for water data directly to your mobile phone or email

How Are Floods Predicted?

USGS data during floods can provide early warning of rapid floodwater rises on major streams. At streamgage sites the water level is observed and then these data are transmitted so that it can be available real-time. Field crews are sent out during floods to take discharge measurements used to verify the data USGS provides to the federal, state, and local agencies, as well as to the public

Streamgages provide long-term data that scientists need to better understand floods and to define flood-prone areas as well.

There are about 250 USGS-operated streamgages in Illinois that measure water levels, streamflow, and rainfall. When flooding occurs, USGS crews make numerous discharge measurements to verify the data USGS provides to federal, state, and local agencies, as well as to the public.

More Flooding Resources

Illinois Flooding Resources

This page contains information and data regarding historic flooding conditions. Each flood from 1995 to 2011 is included on this page.

USGS Real-Time Streamflow for Illinois

Real-time data typically are recorded at 15-60 minute intervals, stored onsite, and then transmitted to USGS offices every 1 to 4 hours, depending on the data relay technique used. Recording and transmission times may be more frequent during critical events. Data from real-time sites are relayed to USGS offices via satellite, telephone, and/or radio and are available for viewing within minutes of arrival. All real-time data are provisional and subject to revision. Build Real-Time Table Show a custom real-time summary table for one or more stations. Build Time Series Show custom graphs or tables for a series of recent data for one or more stations.

Flood Inundation Mapping in Illinois

The U.S. Geological Survey (USGS) streamgages have always been a valuable tool for local officials to help keep people and property safe during floods. The data available from these streamgages are now being taken a step further by mapping inundation surfaces associated with a range of gage heights corresponding to various out-of-bank flows and presenting them on the web.

USGS Flood Publications

Flood of September 13th through 16th 2008 in Northeastern Illinois

Major flooding occurred in northeastern Illinois during September 13-16, 2008, following extended storm activity.

What is a 100 year Flood?

The term "100-year flood" is really a statistical designation, and there is a 1-in-100 chance that a flood this size will happen during any year. Perhaps a better term would be the "1-in-100 chance flood."

A National Threat (2006)

In the late summer of 2005, the remarkable flooding brought by Hurricane Katrina, which caused more than $200 billion in losses, constituted the costliest natural disaster in U.S. history.

Where They Happen and Whyread full article

The spatial distribution of large gaged floods throughout the United States shows that the locations of most of the largest flows are related to specific combinations of regional climatology, topography, and basin size.

USGS Home Water Resources Biology Geography Geology Geospatial

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information:
Page Last Modified: Tuesday, 04-Jul-2017 09:56:24 CDT