Northeast monsoon: Threat of flooding looms over Chennai city

CHENNAI: The city is going to receiving a pounding from the rain gods, and denizens are anxious over the lack of preparedness by the Greater Chennai Corporation (GCC).

The construction of many storm water drains (SWD) in several neighbourhoods remain incomplete, and the open pits pose a huge safety hazard to pedestrians and commuters.

Incomplete work

Two years ago, the GCC constructed a SWD at Thanikachalam Nagar in Madhavaram to prevent inundation during the monsoon seasons. The neighbourhood has 60 streets with more than 1 lakh residents.

However, water stagnation continued to be a problem even during moderate rainfall, as the SWDs were not interlinked. So, the local body decided to expand and link it to the existing drain recently. Six months later, the construction is incomplete and the SWD that was dug up remains open.

As the northeast monsoon is likely to commence in the next two days, the construction work has been halted.

R Ponnusamy, secretary, Lakshmi Nagar residents’ welfare association, Thanikachalam Nagar lamented: “When the Corporation constructed a SWD, we thought it would bring relief from water stagnation. However, it still persists, as the civic body failed to interlink the SWD. During the cyclone-induced floods last year, the area was inundated with chest-level rainwater. Then, they dug up the existing SWD to expand and interlink it, but the pace of work was very slow, and shortage of manpower worsened the situation. The surplus water from Kolathur and Retteri flows through the SWD, and yet, they fail to complete the interlink before the monsoon begins.”

During the intermittent rainfall in the last few days, the area was flooded from the open incomplete SWD. Residents fear that it would again be flooded this year, much like the previous monsoon seasons.

“We’re tired of giving petitions to the Mayor, Chief Secretary and CM cell. No inspection or action has been taken to speed up the construction work. Authorities failed to install motor pumps despite the prediction of heavy rains in the coming days,” said DK Shanmugam, treasurer, Federation of North Chennai Residents Welfare Association.

Government’s inaction

Similarly, even with mild showers, residents of Old Washermenpet struggle with knee-deep water stagnation, which the local body fails to pump out. Recently, SWD construction began, which has stopped for now.

“After all these years, the State government took up the drain works but now that it has stopped, our struggle will continue this monsoon,” rued a resident.

On the other hand, the pace of the SWD construction at Ram Nagar in Velachery, which began a month ago, was very slow. It is one of the many areas that gets inundated during rainy seasons every year.

“After the 2015-floods, it took around six months for the situation to go back to normal. We’re yet to receive the kind of heavy rains that we saw then but for the mild showers, the area is inundated for two days, and water entered almost all the houses,” stated V Thirumurugan, a resident of Ram Nagar.

Even during Cyclone Michaung, when the area was flooded, no government authorities came for inspection or even enquired about the situation. “It took several days for the stagnated rainwater to drain. Though officials are aware of the situation, only now they have dug up the road for SWD works, which remains incomplete. We’ll have to suffer inundation yet again,” he added.

Additionally, on ‘X’ platform, the public posted photos of the current state of Justice Sundaram Road in Mylapore, which has become sludgy and dangerous to commute, due to the open SWD pit.

Missing links

Though the Corporation constructed SWDs, they have not been interlinked in many areas, especially in the expanded neighbourhoods under the Corporation limit.

Residents of Shollinganallur stated that the Perumbakkam lake was enhanced to store excess rainwater from the locality. However, only if the drain is interlinked to the nearby waterbody, it would prevent stagnation during the northeast monsoon, which the civic body has not done.

“Since they have not interlinked the existing SWD to the Perumbakkam lake and Ramanthangal lake, the area gets inundated every monsoon. We’ve raised several complaints to the officials concerned about it but we haven’t received a response yet. It looks it will flood this year too,” said Dinesh Thillaiyappan, a resident of Sholinganallur.

Likewise, there has been no effort made to interlink the existing SWD at Madipakkam. “Civic body workers never complete the work on time here. When there is intense rainfall, residents here struggle with chest-level water every year,” rued R Krishnakanth, a resident of Lakshmi Nagar, Madipakkam.

Filthy waterbodies

Desilting canals, and removing garbage and water hyacinth play a vital role in preventing inundation. It also allows excess rainwater to flow through to the channels and lakes in the residential areas.

Otteri Nullah, one of the important channels in north Chennai that drains surplus water from the various parts of central city to Buckingham canal, has not been desilted. The Water Resources Department (WRD) has failed to desilt the waterbody, nor has it removed the waste and mud on the bund.

Furthermore, the rapid increase in urbanisation around Otteri Nullah interrupts flow of rainwater from various parts of north and central Chennai. Over a period, residential buildings were constructed near the bund of Otteri Nullah, which eventually shrunk the water body.

“If there are no encroachments, it would have carried 3,500 cusecs of water during the monsoon season,” pointed out S Thirunavukarasu, retired PWD, assistant executive engineer. “Removing the encroachments and restoring the water bodies are permanent solutions to prevent flooding. But that would take more than 10 years at least.”

Similarly, the Velachery lake has been filled with plastic waste, and untreated sewage discharged from the residential and commercial buildings and water hyacinth. Excess rainwater from residential areas in Velachery, Madipakkam and Pallikaranai flows into the lake during the monsoon.

However, authorities have not desilted the lakes or removed the floating waste from the water body. And, no steps have been taken to increase the storage capacity.

Official response

GCC Commissioner J Kumaragurubaran, said, “We’ve not commenced new SWD construction. Majority of the construction and interlinks works have been finished. In places where there is no SWD or incomplete drains, motor pumps have been installed to pump out stagnated rainwater from the roads. Zonal officials are instructed to focus on vulnerable areas and ensure excess water is drained out immediately.”

At least 13,000 volunteers are ready, and 113 HP motor pumps are kept in low-lying areas. Railway culverts have been desilted. A total of 10 tractor pumps are stationed at Thiru Vi Ka Nagar (Zone 6) and over 400 tractors are arriving in Chennai after a red alert was issued for the city.