Rural Somonauk intersection closed due to large sink hole, says DeKalb County engineer

The intersection of Chicago Road and Governor Beveridge Highway in rural Somonauk Township is closed until further notice due to a large sinkhole that developed in the area, confirmed DeKalb County highway officials Friday.

According to a social media post published Friday at about 10 a.m. by the DeKalb County Sheriff’s Office, the intersection was closed by the DeKalb County Highway Department due a “possible large sink hole. Drivers are asked to find an alternate route.”

Nathan Schwartz, county engineer with the highway department, said the closure is expected to last into June.

“We don’t expect it to be open next week, but we also don’t expect it to be closed for a prolonged period of time,” Schwartz said Friday. “We are working with contractors to get it done just as quickly as possible.”

Schwartz said there are homes and Somonauk United Presbyterian Church nearby, but everyone is still able to access their driveways.

County officials believe the sink hole was caused by an 18-inch wide piece of tubing carrying water underground that has malfunctioned, Schwartz said. The tubing, called field tile, is pipe buried under ground meant to carry groundwater to an outlet such as a stream or ditch.

Schwartz said he believes the broken clay tile could be between 75 and 100 years old. He said crews were preparing to replace it but over the past 24 hours, the problem expanded.

“We believe the tile has partially failed,” Schwartz said. “And when a tile fails, there is a break in the tile, and when it’s flowing water, it will start to suck the material that is backed filled around that pipe.”

That phenomenon will create a hole in the road, Schwartz said.

“As a void is created more dirt from above falls down to the fill the void,” Schwartz said. “Kind of like a bubble which worked its way to the top. However, if enough dirt is sucked away, it just becomes a gigantic hole.”

About a week ago, highway officials noticed a depression in the road, Schwartz said.

“For the public safety, we needed to close the road,” Schwartz said. “We are out there doing some digging trying to relieve the water pressure from underneath the road.”

Schwartz says they would normally do the work themselves but given the conditions and the depth of the tile they are working with contractors to get it back open.

This is a developing story and could be updated as information becomes available.