River level information is monitored at the Kerby gauge which is near the Highway 199 Bridge. Actual flows in the canyon will be higher due to several tributary streams.
Low flows on the Kerby gauge requiring technical boating skills are below 1000 cfs, and most consider ideal boating levels to be between 1500 and 2500 cfs. Higher flows can pose extreme dangers particularly for rafts that are susceptible to flipping in a couple of the bigger drops. A swim and subsequent loss of your boat could be disastrous.
Discharge on the Illinois can rise an order of magnitude in just a few short hours. Be prepared to stay an extra day or two if necessary to wait out high flows. Veteran Illinois River runners know to watch the weather carefully and stay away when heavy rains and flooding are in the forecast. Water levels come up very quickly and fatalities have occurred when groups pushed on ahead with the water level rising. You can check the National Weather Service Illinois River Forecast. Keep in mind that while this forecast generally provides useful information regarding the trend, the actual forecast values are not always accurate particularly as a storm system is developing. The decision to launch should be made based on current river levels and the three-day weather forecast for rain or hot weather that could melt snow and raise river levels to dangerous heights.