12 Mile Long Ice Jam Causing Severe Flooding in Illinois

Currently in Illinois, residents of Wilmington and the surrounding areas are in a state of emergency. Evacuations are currently underway as an ice jam break along the Kankakee River is causing severe flooding. The sudden rise of the river, about 3 feet, has prompted a Flash Flood Warning for Will and Grundy counties, specifically affecting the areas between Wilmington and Phelan Acres.

Will County officials have reported flooding on the North and South Islands, affecting approximately 200 homes along the river. The Will County Emergency Management Agency has issued a mass notification urging residents to evacuate, and a reverse 9-1-1 was deployed. As of Friday morning, 14 individuals have been successfully evacuated to a temporary shelter, and Route 53, between 102nd Street and 1st St., is closed until further notice. The large ice jam, spanning about 12 miles along the Kankakee River, is one of the largest ever seen, and its melt poses further threats, including potential damage to structures downstream as ice chunks flow with the water.

The power and movement of an Ice jam is a sight to behold. I know first-hand as we have had one before in a small area of the Maquoketa River through the heart of Cascade, Iowa in 2019.

My wife took the video while she was out on a walk with our twins. My daughter Swayer would be the one talking about "ice-surfing." Not happening kiddo!

Ice jams occur when floating river ice accumulates and obstructs the normal flow of the river current. According to the International Association of Hydraulic Research (IAHR), an ice jam is a "stationary accumulation of fragmented ice or frazil that restricts flow" on a river or stream. These jams can take various forms, including surface jams, narrow-channel or wide-channel jams, and hanging jams. By the way, Iowa, Illinois, and Wisconsin are all especially prone to ice jams at this time of the year. In fact, Wisconsin has been ranked as a top state for ice jams in recent years.

In the northern hemisphere, rivers flowing from north to south are more susceptible to ice jams. These events are common during the springtime when river ice begins to break up. Ice jams may form dams that flood areas upstream, and as they break apart, a sudden surge of water can flood downstream areas. The consequences can be severe, damaging structures along the riverbanks and causing disruptions to wildlife habitats.

One of the challenges with ice jams is their unpredictable nature. Changes in temperature, river flow, and the structure of the riverbed can contribute to the formation and release of ice jams. In the case of Wilmington, the surge in water levels and the frozen obstacles in the Kankakee River have led to hazardous conditions, prompting evacuations.

Early warnings are crucial in managing the risks associated with ice jams. Trained observers monitor break-up conditions, and ice motion detectors can provide valuable information. Prevention measures may include weakening the ice before break-up by cutting or drilling holes, dusting the ice with dark-colored sand, or controlling the timing of break-up using ice breakers, towboats, or other means.

Residents in areas prone to ice jams should be aware of the risks and have evacuation plans in place. Emergency services and disaster agencies play a crucial role in monitoring river conditions and providing timely warnings to residents. Communication is key, as illustrated by the reverse 911 issued in Wilmington to advise residents of rising water levels and the need to evacuate.

As communities in Wilmington and other regions affected by ice jams navigate these challenges, understanding the causes and consequences becomes imperative. Ice jams require proactive measures, vigilant monitoring, and community resilience to mitigate the potential impact on lives and properties.