An extended closure of Chatham’s Grand Avenue West is planned beginning Monday.

The Municipality of Chatham-Kent blames a drainage culvert failure near the Ontario Court of Justice for creating a sinkhole on the main roadway.

The discovery of the large sinkhole under the westbound lanes of Grand Avenue prompted an immediate closure of the two lanes. Further inspection identified the cause of the sinkhole to be a failed drainage culvert under the road that allows water to drain to the Thames River.

According to Tim Dick, the director of drainage, assets and waste management for the municipality, says the repair is complicated and will require deep excavation.

The work will see Grand Avenue West closed completely for through traffic for an extended period. All businesses will remain accessible as well as the court building, the Chatham-Kent Children’s Treatment Centre and the Chatham-Kent Health and Family Services Building.

The municipality says detour signs will be set up at Grand Avenue and Lacroix Street and Keil Drive.

Richmond Street via Lacroix Street and Keil Drive will be the designation detour route through the traffic.