Mindless digging ahead of the Commonwealth Games turned more roads into ditches during Thursday's downpur. Ashoka Road and Kasturba Gandhi Marg, under the jurisdiction of the New Delhi Municipal Council (NDMC), caved in on Thursday, unable to take the pressure of the increased traffic volume due to waterlogging.
In south Delhi, Aurobindo Marg — which has collapsed a number of times in the past too — pulled off a repeat feat.
Passengers traveling in a blueline bus near AIIMS had a narrow escape when the rear wheel of their bus jammed into a 5-feet deep ditch formed when the road underneath caved in. "The road leading to IIT Gate from AIIMS caved in. A storm water drain of MCD is flowing underneath it, so due to constant seepages the soil became loose," said a PWD official.
Why does this happen
Experts say that proper restoration work is not carried out after stretches are dug up for laying utility services, including communication lines and electricity cables.
"Telecom service providers and distcoms are carrying out a lot of digging. However, they don't dig up the entire road but merely 1-or 2-metre stretches for laying the lines. The stretch is covered using loose soil, which is not able to settle due to the rains. This also leads to development of gaps underneath the road," said P K Sarkar, faculty, department of transport planning, School of Planning and Architecture.
"The stretch being very small, it becomes impossible to settle using a roller. Over a period of time, water starts seeping in, the soil becomes soft and gives way when it rains heavily."
Sixteen roads have caved in so far this monsoon.
In New Delhi area, five roads caved in the last 72 hours — both Rajesh Pilot Marg and Ashoka Road caved in twice on two different days.
Civic agencies blame the depletion in groundwater for making the roads hollow.
"Over the years, the groundwater has depleted but during monsoon the water table rises. The pressure of the water pushes away the soil underneath the road, making it vulnerable," said NDMC spokesman Anand Tiwari.
The civic agency also claims it is impossible to avoid such incidents as most Delhi roads have been constructed over water pipelines, which over a period erode, leading to constant leakages.