The area, which was hit by heavy flooding in the first week of December, has been seeing sewage overflow
Despite the rains having stopped more than a week ago, several sewer manholes in Velachery are still overflowing and causing severe hardship to residents.
Several streets in Velachery, which were hit by heavy flooding in the first week of December, have been seeing sewage overflow.
Every year, the residents here face the issue of manholes spewing out sewage after the rain stops, with streets located on the perimeter of the Pallikaranai marshland bearing the brunt of the issue. Several areas including Annai Indira Nagar, Venus Colony, Bethel Avenue, Dhandeeswaram Nagar, Tansi Nagar, Udayam Colony, Vijayanagar, Ram Nagar, AGS Colony and Muruga Nagar have been facing this problem.
The residents said not renovating the sewage pumping substations, which were commissioned more than a decade ago, was the main cause of the overflow.
S. Kumararaja, convenor, Federation of Velachery Welfare Association (South West), said the pumping stations located at Muruga Nagar, Bypass Road and Baby Nagar have not been renovated since they were constructed more than a decade ago. He said the federation, containing a number of residents welfare associations, had given a representation to the Chennai Metro Water Supply and Sewerage Board (CMWSSB) to increase the capacity of the pumping stations. Velachery, having become a separate Assembly constituency, now has a large number of residential and commercial buildings, he added.
The jet rodding and super-sucker machines of the Metro Water could be seen engaged in removing silts to stop the sewer overflow on several streets in Velachery. But this was little use, said the residents.
During the recent rains, the sewer network in the city that usually carries around 550 million litres a day of sewage pumped nearly 980 mld, including rainwater. It led to issues of sewage overflow in many places.
In Velachery, the sewer network that carried the additional load was silted up. As there were no proper storm water drain networks in low-level areas, sewer networks became the rainwater drain. The sewer pipelines in Velachery, which were commissioned to carry up to 90 mld, received an additional load of 130 mld during the rains. The system carried more load than its capacity, leading to the damage of manholes and the pumping lines.
There is no proper channel in certain areas of Velachery to drain the floodwater into the Pallikaranai marshland. Instead, the rainwater is diverted into the sewer network.
“We are now desilting and flushing the lines. There are about 8,000 manholes in Velachery alone. We are desilting 150 manholes daily and flushing 2-3 km daily to clear obstructions and ensure better flow of sewage,” said a Metro Water official.
Ten different equipment, including the super-sucker machines, were being used to desilt the network in areas such as Taramani, MGR Nagar and Maduvankarai. Work would be completed by the end of the week, the official added.