A large sinkhole that developed in a forested area of Riverside, north of Ogden Avenue and west of Miller Road, remains a hazard more than a year after officials believe it appeared.

The roughly 5-foot diameter sinkhole is the result of a collapsed sewer structure, according to Public Works Director Edward Bailey. Looking into the sinkhole, which is largely filled with water at this time, one can make out what appears to be a brick vault.

And while the remains of a 19th-century brewery are buried near the site, officials have definitively confirmed that the structure that’s visible inside the hole is not related to the old Mueller’s Brewery, which was destroyed in a fire in 1873.

Bailey said he’s not sure how old the drainage structure is, but it is part of a combined sewer line that discharges into the Des Plaines River, just to the west of the sinkhole. It’s believed that the sinkhole appeared in the wake of the heavy rain and flooding of April 2013, said Bailey. 

It is unclear how deep the water in the sinkhole is, but the water level is several feet below the ground. Riverside Village Manager Peter Scalera said the village has known about the sinkhole for about six months. The area is surrounded by plastic hurricane fencing, but it’s easy to step over the fencing to get closer to the hole.

Although the sinkhole is on property belonging to the Cook County Forest Preserve District and although there is a Metropolitan Water Reclamation District of Greater Chicago sewer line nearby, the drainage structure that has collapsed is owned by the village of Riverside, said Bailey.

As a result, Riverside is on the hook for repairing the damage. The reason it’s taken so long to get the work done, said Scalera, is that Riverside would like some help paying for the job.

“It’s a pipe shared by a number of [governmental agencies],” said Scalera. “We’re trying to work with the MWRD on cost sharing to make the necessary repairs.”

According to Bailey, the other agencies benefiting from the sewer outfall to the river include the MWRD, the Illinois Department of Transportation (storm runoff from Harlem Avenue), the city of Berwyn and, possibly, Lyons.

“If others are using the pipe, they should participate in the maintenance of it,” said Bailey. “Riverside doesn’t expect to be paying for the maintenance on the structure [by itself].”

But Scalera said he’s not sure if the village will be getting any financial help from other agencies, and since the pipe actually belongs to Riverside, they must fix it sooner or later.

“It may come down to us eating it and making the repairs,” Scalera said.

Bailey said he is in the process of soliciting prices for repair and that he should have some idea of the cost within the next month. One of the things that could affect the cost is the condition of a check valve near the river outfall, which prevents water from back-flowing into the pipe when river levels are high.

There is quite a bit of water in the collapsed part of the sinkhole, and Bailey isn’t sure what the source of that water is.

“The check valve might be damaged, and if it is, water will back-flow in,” said Bailey. “We need to check on that.”

There’s still no timetable on when the repairs to the sewer structure will be made and the sinkhole filled in.