CHENNAI: Though the impact of Michaung in Chennai was not evenly spread, all low-lying areas across the city were identically hit. The topographical gradient of stormwater drains (SWD) and width and depth of the local waterbodies determined the pace at which the floodwater drained from these areas.
Manapakkam and Mugalivakkam were among worst-hit areas in 2015. Areas under ward 156, Thiruvalluvar Nagar, were severely affected during the previous monsoon. Alandur Zone has 929 SWDs to a length of 179 km. Of this, about 192 drains to a length of 39 km are in ward 156.
Manapakkam canal is the sole macro drain in the zone that runs from Porur lake to the Adyar carrying surplus water from Porur and Chembarambakkam lakes. “The width of the canal used to be three times its present size. It has shrunk over the years owing to the rise in residential buildings. The width and depth of the canal too is uneven,” said Natarajan G, a resident of Porur for 46 years.
The areas adjoining the canal were worst hit as water overflowing from the canal marooned them. After 2015, the Public Works Department raised the height of the retaining walls. Despite that, low-lying areas like Thiruvallur Nagar suffered heavy inundation this year.
However, Sabari Nagar in Mugalivakkam, which is usually flood-prone, saw lesser inundation during Michaung. The stormwater drain is on a higher gradient than the canal in this area, thereby enabling free flow of water. “There was knee-deep water on Monday. But it drained within a few hours after the rain stopped,” said Prema B, a resident of Sabari Nagar
On the other hand, areas like Thiruvalluvar Nagar suffered inundation for more than three days. The corporation deployed pumps to drain water from low-lying streets and SWDs. The Manapakkam canal carrying water beyond its capacity was one of the major reasons for inundation. To reduce water flow in the Manapakkam canal, the PWD is constructing five micro canals to divert water. “Once these micro canals are ready, the Manapakkam canal won’t be flooded. We have also identified vulnerable areas along canals and instructed the PWD to raise the height of the retaining walls,” a corporation official said.
SVS Nagar in Valasaravakkam also suffered heavy inundation for more than three days. Residents allege that SWDs were unable to drain water due to blocks. “The drains were clogged and pumps had to be deployed to clear stagnant water,” said Ganapathy, a resident of Valasaravakkam. Corporation officials acknowledge that SVS Nagar remains a challenge. “The effectiveness of SWDs will be properly assessed and improvements made,” a senior corporation official said.
‘Conservancy workers refuse to use safety gear’
Chennai: Chennai Corporation Commissioner J Radhakrishnan on Friday told a division bench of Madras HC that conservancy workers refuse to use safety gear like mask and gloves as they find them inconvenient. He said he had even warned the workers of imprisonment if they continued to work without such gear. The bench held that the ban on manual scavenging would apply to waste segregation too and wanted steps for source segregation.