A 7-mile-long ice jam on the Kankakee River threatens to cause flash flooding in southwest suburban Wilmington — although the phenomenon should be no stranger to area residents, officials say.
Wilmington police are concerned that the ice jam, which has risen to the bottom of a bridge that carries traffic on Interstate 55 across the river, could thaw and quickly flood low-lying areas.
Wilmington officials decided to go door-to-door on Friday to alert residents of the potential for flash flooding, police said.
Wilmington happens to be on a part of the Kankakee River that is very curvy and primed for ice jams, according to National Weather Service meteorologist Gino Izzi.
“The thing with ice jams is they’re really unpredictable,” Izzi said. “Any year we have a cold winter, this happens. With the warming temperatures, it will lead to rising water. If it breaks up quickly there could be flooding.”
Temperatures in Wilmington are expected to rise into the 40s on Sunday and the low 50s on Monday, according to the weather service. Light rain is possible Sunday morning with heavier showers expected Sunday night into Monday morning.
The Army Corps of Engineers developed a plan in the 1990s to address ice jams on that section of the river by diverting heated water from a nearby nuclear power plant into the river.
The Dresden Nuclear Power Station usually takes in water from the Kankakee River for the facility’s cooling process, and discharges that water in the Illinois River, the Illinois Environmental Protection Agency said in a statement.
When ice starts to pack on the river, the power station diverts some of that water back to the Kankakee river, the agency said.