Measuring the Floods in Illinois

Crews from the USGS are measuring the floods of rivers and streams in Illinois. It’s estimated that current conditions of the waterways are the highest levels in over 20 years for the state.

Scientists from the U.S. Geological Survey (USGS) are tracking the floodwaters, which are expected to be moving downstream of the Illinois River, the Rock Rivers, and other major waterways for the next few days. Many of the rivers may result in large flooding that overtop levees around the area. Since flooding began on April 16, there are 53 USGS streamgages that are already at or above flood levels.

"These measurements are made using state-of-the-art equipment, including hydroacoustic meters, which gives the USGS the ability to make accurate and reliable streamflow measurements under extreme flow conditions," said USGS hydrologist Gary Johnson. "Accurate streamflow measurements are critical for emergency managers to make important decisions on how to protect life and property."

Measuring the flood water is critical in helping to protect lives, property, the environment, and to give ample warning for those that may be in the paths of the floods. In total, there are 250 USGS streamgages in Illinois that measure the water levels, streamflow, and rainfall of the waterways. These streamgages help the USGS provide more accurate information to local, state, and government agencies, and the public, especially when there is potential for flooding.