The inundation map at the following link has been updated as well.
https://idnr.maps.arcgis.com/apps/instant/basic/index.html?appid=b3074e300da345e588b96919e023ffbe
Please use and share the following Flooding Impacts link to allow the Office of Water Resources to better correlate gage readings through the system to community impacts.
The better the data that the office has, the better informed the decision-making process will be regarding water levels.
The Fox River Status Update for April 20, 2026 is available at https://dnr.illinois.gov/waterresources/strattonoperationsupdate.html
SUMMARY
The good news is that inflows have peaked (Figure 1). Fox Lake is now forecasted to peak between 7.3’ and 7.4’ on Wednesday, with the Upper River and Pool slightly lower (Figure 2). The Lower River is now currently expected to crest near 7.5’ on the Fox River (Tailwater) Near McHenry Gage, (Figure 3). There is currently between 0.25” and 0.50” of rain forecasted for the watershed over the next 7 Days, (Figure 4).
Aaron Rotherham
Project Engineer
IDNR Office of Water Resources
(217)782-4615
