3 days, 7 cave-ins: Delhi’s roads fail to withstand heavy rain spells
Delhi traffic police officials said that with two portions on the Mahipalpur route affected, traffic on Thursday was severely hit.Updated: Jul 24, 2020 02:38 IST
Just three days of heavy rain in the national capital have caused cave-ins on sections of at least seven major roads in the city, further slowing traffic that was already moving at snail’s pace due to the showers and floods.
Just a day after parts of roads slumped in two vital stretches in central and south Delhi —Ashoka Road and Mahipalpur bypass—another section of NH-48 leading to Mahipalpur and a portion of the service lane near the Rajouri Garden main market caved in on Thursday morning.
Delhi traffic police officials said that with two portions on the Mahipalpur route affected, traffic on Thursday was severely hit. Traffic from NH-48 towards Mahipalpur bypass, which is under the jurisdiction of National Highways Authority of India (NHAI) and the Central Public Works Department (CPWD), and that coming from Vasant Kunj towards the airport, on both sides of the carriageway, was diverted on the day, as a result.
PWD minister Satyendar Jain did not respond to requests for comment.On Tuesday, traffic on and around Bhairon Marg came to a standstill after a section of the primary connection between central and east Delhi caved in, forcing traffic police to divert traffic.
Since Tuesday, such incidents have also been reported from ITO in Central Delhi and Nawada in West Delhi. In the three days since then, Delhi has seen 122mm of rain. But why do such cave-ins take place?
Senior officials of the city’s road-owning agencies — the Public Works Department (PWD), Delhi Development Authority (DDA), National Highways Authority of India (NHAI), and the four municipalities (east, north and south Delhi municipal corporations and the New Delhi Municipal Council) said these are recurrent incidents every monsoon, and attributed cave-ins to damaged water or sewer pipelines beneath roads. Experts added that shoddy quality control during construction compounded the problem.
A PWD official said a small portion of Rajouri Garden market road caved in due to sewerage leakage. “The leakage was attended to promptly and fixed. The portion is cordoned off and will be repaired soon,” the official said.
Officials said there was a similar problem at Ashoka Road on Wednesday afternoon. Officials of the New Delhi Municipal Council (NDMC), under whose jurisdiction Ashoka Road is, said there was a leakage in a sewer line passing beneath the road, which led to the incident. “A small portion caved in because of a leak in the underground sewer line. Our engineering team is working to repair the sewer line and the road on priority,” NDMC spokesperson RN Singh had said Thursday.
NHAI and CPWD did not respond on the details of the cave-in on Mahipalpur bypass and NH-48.
Estimates from the traffic police show that over the last five years, the most complaints of roads caving in have come from central Delhi, which experts said was because most underground systems in the area were laid during British rule, and have not been replaced since.
A large portion of Bhairon Marg, just a few metres away from the present cave-in, had slumped in 2016. Sections of Ashoka Road have caved in at least thrice in the last two years, official records confirmed.
Sarvagya Srivastava, former engineer-in-chief of PWD, said many old utilities in Delhi such as water and sewer lines are laid beneath roads, and that whenever there is damage to these utilities, water seeps in, and the lower soil layer becomes soft.
“Before constructing a road, the water or sewerage pipelines should be shifted to a multi-utility duct or underneath a footpath or to the side. But at many places in Delhi, roads are built on these utilities due to a shortage of space. So, when these utilities leak, the water makes the soil soft and after some time, with continuous load portions of the road collapse,” Srivastava said.
Sewa Ram, a professor at School of Planning and Architecture (SPA), said that apart from leakage in utilities, another cause for such incidents is “bad engineering” while laying roads. “If the lower layers are not compacted properly, the chances of a road cave-in increase,” Ram said.