The welcomed heavy rainfall in Calumet City on Sunday brought with it an unexpected disaster, according to CBS Chicago. A sewer in the southern part of the city exploded after its storm water system was overwhelmed by the torrential rainfall, leaving behind a gigantic crater. WGN TV reported that the hole was at least 10 feet deep.
The Storm
This was no pleasant spring shower. The storms that moved across the area caused massive flooding on several city streets, according to an article published by CBS Chicago. ComEd, the area’s electric company, told the news outlet that 9,000 of their customers reported power outages as a result of the storm, and over a hundred flights at O’Hare International Airport had to be canceled that day.
The article went on to say that the storm system poured over an inch of rain in only 20 minutes, with an average of 2 inches per hour after that.
The rain was so heavy that Bridgeview storm drains couldn’t keep up, so water pumps had to work throughout the night to clear the city’s flooded streets. Likewise, in Calumet City, the Deep Tunnel storm water system was overwhelmed by the rainfall, which was what resulted in the explosion.
The Explosion
Residents of the city who live near Burnham Avenue and Heritage Drive told ABC Local News that the explosion of water, which sounded like a loud clap of thunder, caused rocks and boulders to fly up into the air.
“You heard a big boom. And then I turned around and the water was coming up and it was like an ocean. Everything in the parking lot was moving and it wasn’t stopping,” Sharon Krueger said.
Metropolitan Water Reclamation District executive director David St. Pierre told CBS Chicago that the rain caused too much pressure to build up in the sewer, resulting in a hydraulic explosion that blew a manhole cover and concrete into the air.
“Water is coming in at tremendous pace. That water builds up that air pressure,” he said. “Water is displacing air, so you have a combination of hydraulic water pressure and air pressure, and that force is extremely powerful.”
Another resident, Debbie Pawlak, told CBS Chicago that water spewed up and over the telephone wires.
According to WGN TV, the only damage from the blast was some flood damage to the basement of a nearby building. Fortunately, no one was injured, despite the flying debris and gushing water.
Not A Rare Occurrence
Believe it or not, similar explosions have happened in the area within the last few years. According to ABC Local News, the area has had problems in the past with geysers erupting during heavy rain. Work has been done to correct the problem, but, obviously, a new solution is in order.
Residents told CBS Chicago that this same thing has happened three times in the last four years. Last year, flying debris damaged cars in a nearby parking lot.
“We put in some restrictors in the past that help restrict that pressure, so that it bleeds off. We put in some vents so that air can escape,” St. Pierre told CBS Chicago. “Obviously, we’re going to have to do some more investigation and calculations and see what we can do this time.”
CBS Chicago went on to say that St. Pierre’s department will be opening a reservoir next year that will hopefully stabilize the pressure and prevent explosions in the future.
