As Delhi goes on a construction overdrive for the Commonwealth Games, building new roads and flyovers, the existing ones are already giving in.
Last week, four roads across the city caved in within three days, leaving 10 to four feet deep craters.
On May 29, 40 passengers travelling on a low-floor DTC bus escaped narrowly when the bus sank into a 10-foot crater on a road in Geeta Colony. The same day, another road in Rajouri Garden caved in, leaving behind a five feet deep hole.
On May 31 and June 1, two more roads — in Hardev Nagar and the Moolchand-BRT stretch — caved in.
Experts have warned if proper procedures are not followed, such incidents will just multiply in the coming months.
These roads are hollow beneath because they have been built over water and sewerage pipes, experts said. When pipes start leaking, the concrete and bitumen filling (layers of the road) are washed away, leaving massive holes in the road.
"Before a road is constructed, water pipes are supposed to be shifted underneath a footpath or on the side of the proposed road," said Dipak Mukhopadhyay, former MCD engineer-in-chief.
"Even after it is shifted, it has to be ensured encasing (concrete covering of the pipeline) is carried out so there is no contact between the pipeline and the road. In all recent cases, this procedure was not followed."
The Geeta Colony road, for instance, was laid over a water pipeline and due to constant leakages the road developed a 10-foot deep crater.
The MCD refused to take blame for the mess.
"There is water line of the Delhi Jal Board under the road and due to frequent leakages the soil became loose and give way," said Deep Mathur, director press and information, MCD.
"It's DJB's job to keep a check on such leakages."
DJB officials did not comment on the issue.