Chennai: Third sinkhole in 5 yrs in Pulianthope worries residents, motorists

CHENNAI: A massive sinkhole measuring around 15 feet in diameter and 10 feet deep developed on Perambur Barracks Road near the sewage pumping station in Pulianthope on Tuesday afternoon, raising concerns over the condition of an ageing underground sewage pipeline.

On being alerted, Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) officials barricaded the area to prevent accidents and initiated rectification work.

Locals said that the layer beneath the road had eroded as a 1,200-mm diameter sewage pipeline runs below the affected stretch. According to residents, sewage from Purasawalkam and Kellys is pumped to the old sewage pumping station on Perambur Barracks Road through the pipeline, which is around 50 years old. They said that deterioration of the pipeline over the years could have resulted in soil erosion and the subsequent collapse of the road.

The latest incident has also brought back concerns over repeated cave-ins at the same location. Similar sinkholes of comparable size were reported in October 2021 and November 2022, with officials attributing the earlier incidents to damage to the sewage pipeline.

Activist and Pattalam resident V Sathiya Balan alleged that authorities were adopting temporary measures by repairing the damaged portions of the pipeline instead of examining the condition of the entire pipeline. “A sinkhole has occurred three times in the last five years, putting the public at risk. CMWSSB should find a permanent solution instead of providing temporary relief by repairing the damaged portion every time,” he said.

A CMWSSB official said the cave-in occurred due to damage to the 1,200-mm RCC gravity main leading to the Purasawalkam old sewage pumping station. “The site has been barricaded and the contractor has begun rectification work. Instructions have been issued to expedite the work,” the official said.