The U.S. Geological Service’s National Water Information System maintains a network of stream gauges in partnership with state and local agencies. From the USGS “Current Conditions for Illinois” webpage:
“Streamgages are used nationwide to predict and address drought and flood conditions by monitoring water availability. The USGS and over 850 Federal, State, and local agencies cooperatively fund the USGS streamgaging network, which consists of over 8,000 streamgages.
Streamflow in Illinois is monitored in cooperation with State, County, and other Federal agencies.”
Here are links to the stream gauges on the Fox River:
FOX RIVER (TAILWATER) NEAR MCHENRY, IL (stream gauge downstream of the McHenry Lock and Dam)
FOX RIVER (TAILWATER) AT ALGONQUIN, IL (stream gauge downstream of the Algonquin Dam)
FOX RIVER AT SOUTH ELGIN, IL (TAILWATER) (stream gauge downstream of the S. Elgin Dam)
Fox River Recreational Boating Closures
Fox River Fish Advisories (for species and meal frequency)
The Illinois Department of Public Health issues the following meal advisories for fish found with elevated levels of chlordane, dioxin, methylmercury and polychlorinated biphenyls (PCBs) are based primarily on protecting sensitive populations, most particularly women who are pregnant, nursing, or of childbearing age, fetuses, and children younger than 15 years of age. All advisories may be overprotective for women beyond childbearing age and males 15 years of age and older.
PLEASE NOTE: THE METHYLMERCURY ADVISORY APPLIES TO PREDATORY FISH IN ALL ILLINOIS WATERS. Predator fish include all species of black bass (largemouth bass, smallmouth bass, and spotted bass), striped bass, hybrid striped bass, white bass, walleye, sauger, saugeye, flathead catfish, muskellunge, and northern pike. For more information on mercury in Illinois fish, see the “2018 Special Mercury Advisory and “Facts About Illinois’ Methylmercury Advisory“. For more information about Chlordane and PCBs see “Facts About Illinois’ Chlordane Advisory” and “Facts About Illinois’ Polychlorinated Biphenyls (PCBs) Advisory“.
For Lake, LaSalle, Kane, Kendall and McHenry counties