Total streamflow across the
Illinois River
was last observed at
21,943
cfs, and is expected to yield approximately
43,523
acre-ft of water today; about 42%
of normal.
River levels are low and may signify a drought.
Average streamflow for this time of year is
51,820 cfs,
with recent peaks last observed
on
2015-12-28 when daily discharge volume was observed at
632,800 cfs.
Maximum discharge along the river is currently at the
Illinois River At Henry
reporting a streamflow rate of 5,840 cfs.
This is also the highest stage along the Illinois River, with a gauge stage of
14.46 ft at this location.
This river is monitored from 12 different streamgauging stations along the Illinois River, the highest being situated at an altitude of 1,202 ft, the
Illinois River Near Kerby.
| Last Updated | 2025-12-04 |
| Discharge Volume | 43,523 ACRE-FT |
| Streamflow |
21,943.0 cfs
+554.0 cfs (+2.59%) |
| Percent of Normal | 42.34% |
| Maximum |
632,800.0 cfs
2015-12-28 |
| Seasonal Avg | 51,820 cfs |
| Streamgauge | Streamflow | Gauge Stage | 24hr Change (%) | % Normal | Minimum (cfs) | Maximum (cfs) | Air Temp | Elevation |
|---|---|---|---|---|---|---|---|---|
|
Illinois River Near Kerby
USGS 14377100 |
165 cfs | 2.01 ft | -4.62 | |||||
|
Illinois River At Savoy
USGS 07194800 |
48 cfs | 2.27 ft | 0 | |||||
|
Illinois River At Hwy. 16 Near Siloam Springs Ar
USGS 07195400 |
326 cfs | 6.29 ft | -0.91 | |||||
|
Illinois River South Of Siloam Springs
USGS 07195430 |
295 cfs | 2.87 ft | -1.34 | |||||
|
Illinois River Near Watts
USGS 07195500 |
330 cfs | 2.74 ft | -2.37 | |||||
|
Illinois River At Chewey
USGS 07196090 |
380 cfs | 3.05 ft | -3.31 | |||||
|
Illinois River Near Tahlequah
USGS 07196500 |
487 cfs | 5.35 ft | 0 | |||||
|
Illinois River Near Gore
USGS 07198000 |
113 cfs | 6.76 ft | -14.39 | |||||
|
Illinois River At Marseilles
USGS 05543500 |
3490 cfs | 11.15 ft | 0 | |||||
|
Illinois River At Kingston Mines
USGS 05568500 |
5580 cfs | 3.03 ft | -16.84 | |||||
|
Illinois River At Henry
USGS 05558300 |
5840 cfs | 14.46 ft | 130.83 | |||||
|
Illinois River At Valley City
USGS 05586100 |
5050 cfs | 2.28 ft | -23.95 |
The Illinois River (Miami-Illinois: Inoka Siipiiwi) is a principal tributary of the Mississippi River, approximately 273 miles (439 km) long, in the U.S. state of Illinois. The river drains a large section of central Illinois, with a drainage basin of 28,756.6 square miles (74,479 km2). The drainage basin extends into Wisconsin, Indiana, and a very small area of southwestern Michigan. This river was important among Native Americans and early French traders as the principal water route connecting the Great Lakes with the Mississippi. The French colonial settlements along the rivers formed the heart of the area known as the Illinois Country. After the construction of the Illinois and Michigan Canal and the Hennepin Canal in the 19th century, the role of the river as link between Lake Michigan and the Mississippi was extended into the era of modern industrial shipping. It now forms the basis for the Illinois Waterway.