SOMONAUK – A stretch of Somonauk Road will be closed for more than two months while a bridge spanning Somonauk Creek is replaced.
The section of road, about a half-mile south of Chicago Road in Somonauk and Sandwich townships, will be closed from June 12 to about Sept. 1 while the bridge, built in 1991, is replaced. Martin & Co. Excavating of Oregon will do the job for a shade more than $600,000.
About a mile north, a similar bridge built in the 1970s will be replaced next year.
DeKalb County Engineer Nathan Schwartz said he wondered whether the bridge was done in because people are hauling loads across that exceed posted weight limits.
“It’s a little bit younger than we normally see, but that bridge has much more extensive damage on the underside of the deck, due to what we believe was excessive overweight loads shortly after it was built,” Schwartz said.
The 1991 bridge actually was going to be replaced last year, until the Illinois Department of Natural Resources found a few species of mussels in the area, including the slipper shell, which is on the state’s threatened species list.
The IDNR relocated the mussels, and the DeKalb County Highway Department had to hire an environmental consultant to come in before the construction and make sure none have sprung up or migrated back.
Such bridges are built to routinely handle about 73,280 pounds, although Schwartz said they “could probably hold a 200,000-pound load.”
That is, if you don’t want the bridge to last more than a handful of years.
“But every time the bridge carries an overweight load, it lessens the lifespan of the bridge a little bit,” Schwartz said. “Bridges are designed for standard vehicles, like a standard semi with five axles.
“If you abuse the rules, the bridges are going to fall apart, and it’s more expensive to repair or rebuild a road than it is to do the preventative maintenance.”
For information about the project, or any highway projects around DeKalb County, call 815-756-9513 or email firstname.lastname@example.org. For updates, visit dekalbcounty.org/highway.