The floods were no natural disaster, but one stitched over the last half-a-decade, courtesy poor planning by Greater Chennai Corporation.

Chennai rains waterlogging Water, sewage stagnating on Srinivasan Street
news Chennai Rains Saturday, November 13, 2021 - 17:17

More than 36 hours since the havoc caused by the north east monsoon abated in Chennai, a dozen lanes in Mandaveli near Mylapore – one of the city’s most popular locations – are still water logged on the morning of Saturday, November 13.

The standing water is not just from the skies, but from below the ground as well. Raw sewage from the underground sewerage system (UGSS) has bubbled up to form stagnant black pools; some outside homes and some, even inside. A few metres away, the main roads are free of water enabling buses, cars and two-wheelers to whizz past, in complete contrast to the locals’ misery.

This issue was also the reason why some residents fought with the local DMK cadre on Friday afternoon. More than 200 families live in these lanes; the Mylapore MLA Dha Velu’s office is also in the neighbourhood. Some, like those on Thiruvalluvar Pet street, have water inside their homes and are struggling without power for three days now.

Angry residents are unwilling to accept the reasons given by officials and staff of Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB), who have been working for more than 24 hours to rectify a major pipeline fault in the local pumping station, located on St Mary’s road a few meters away.

Water logging on Saturday morning on Thiruvalluvar pet street off Devanathan street

The fundamental question is – why should residents wait for sewage lines (maintained by CMWSSB) to clear rainwater, which should drain through storm water drains (SWD), constructed and maintained by Greater Chennai Corporation (GCC)? Why is the CMWSSB facing the music for an issue that is the domain of its sister line-agency, GCC? This is no natural disaster, but one stitched over the last half-a-decade, courtesy poor planning by GCC.

In Mandaveli, GCC has constructed SWDs on Devanathan street, a bus route road which is also an ideal model for a Horlicks commercial, given the steady increase in its height. It is at least half a foot higher than lanes around it. It curves right into the St Mary’s road which suffers from the same symptoms. To make matters worse, the residential lanes branching off these two bus route roads don’t have SWDs. This means that rainwater collects into, and stagnates onto, these streets very quickly. On a normal monsoon day, this doesn’t elicit a second glance, as the Underground Sewerage Scheme (UGSS) drains it comfortably. But on a red alert day, it is pure chaos.

Like Arappor Iyakkam’s Jayaram Venkatesan explained in a series of videos on Friday, rainwater draining through UGSS is a recipe for disaster.

Sewage lines are supposed to carry sewage, and SWDs, rainwater. When the latter doesn't exist, it puts the former under great stress. Water stagnates, sewage overflows and makes life miserable for residents.

Officials of CMWSSB and the Mylapore MLA DMK’s Dha Velu, whom I spoke to, agreed and are aware of this. Velu said the inner lanes need stormwater drains and he would soon be moving a proposal with the GCC.

Workers rectifying a pipeline damage at the St mary's road pumping station on Saturday morning.

What’s more, a CMWSSB engineer told me that the sewage system in Chennai is supposed to carry 960 million litres a day, but maybe pumping 5,000 million litres a day, as excess rainwater in many areas drains through their network. However, there is no way to corroborate this because the opaque CMWSSB does not even put out minutes of its meetings online.

The CMWSSB pumping station in St Mary’s road, where the piping failed, is also the nodal point for receiving sewage from as far as Seethammal colony in Alwarpet. “So, the water logging in that area can also be attributed to this pumping station’s repair,” an official said.

Jayaram’s spot analysis on Besant Road in Triplicane on Friday is another exhibit of the same issue. Excess rainwater on the road drained very quickly. “But when I threw a leaf into the storm water drain, it did not move. The water stayed still. This means that the SWD doesn’t work and the rainwater has drained through the sewage network,” he said.

All this points to the requirement of a complete overhaul of the SWD network and also greater transparency in the process. Residents also need to be educated about how things work. If government agencies can’t do that, they should at least make all details available on their website, a requirement as per the Right to Information (RTI) Act.

GCC has constructed and now maintains more than 2,000 km of SWD in Chennai. In addition, there is an SWD network on Anna Salai and Poonamallee High Road, which are maintained by the state highways department. But not a single map of the entire network is available in public domain – an issue that has been the subject of regular clamour. This has also led to speculation if any such document exists at all.

Details about the desilting of drains, where the silt goes, whether drains are connected to each other and how they work are also a mystery to common residents. For instance, it is not common knowledge that sea tides affect the functioning of storm water drains in a coastal city like Chennai. "I know only because I was briefed by a chief engineer of GCC on this subject. This is why water drains slowly at around sunrise and sunset and faster during the day,” he said  

SWDs drain water from roads into the Buckingham canal which drains into rivers like Adyar and Cooum, which end up in the sea. So, during a high tide, canals are unable to drain with as much force into the rivers, which has a reverse effect on the stormwater drain network.

Meanwhile in Mandaveli, two lorries are at work to suck out the stagnating water. But as an official puts it, this is a “temporary bailout”. “The permanent solution is construction of SWDs. The underground sewage system is designed to carry only sewage water. It can’t take rain water,” the official said.

Siddharth Prabhakar is based in Chennai and has covered Greater Chennai Corporation, Railways, DVAC, CBI and other investigative agencies during his six-year stint in Times of India and one-and-a-half years in The New Indian Express. 

Become a TNM Member for just Rs 999!
You can also support us with a one-time payment.