Is Chennai monsoon ready?

How has the city’s stormwater drain project fared? Chennai architects and planners weigh in on other flood mitigation measures
Local residents struggle to cross the flooded Ganeshapuram subway at vyasarapadi during following incessant rains. (Photo | P Jawahar)
Local residents struggle to cross the flooded Ganeshapuram subway at vyasarapadi during following incessant rains. (Photo | P Jawahar)

CHENNAI: Much was said and written about the Greater Chennai Corporation’s (GCC) stormwater drain (SWD) project, which promised to reduce waterlogging and flooding that has been haunting the city each year. With memories of the 2015 deluge fairly fresh in people’s memory, there was much hope and anticipation that the city would be better prepared for the northeast monsoon, what with the GCC racing against time to finish the project. When the rains finally arrived this month, shattering a thirty-year record, the results of the SWD project, while being mixed, are nevertheless promising.

While core areas areas like T Nagar, Adyar, Mylapore and Nungambakkam were spared the usual flooding and waterlogging, other areas, especially those in North Chennai, have not fared as well. And there have been instances of deaths due to electrocution and a roof that collapsed under the brunt of the recent downpour.

The GCC embarked on building stormwater drains after several successive monsoons exposed the city’s faults in terms of infrastructural preparedness. In any infrastructure project, it is almost a given that the public would have to put up with some inconvenience until works are complete. It’s been very much the same with the SWD project, which began in summer this year and since then has been a source of much consternation among commuters, with traffic diversions, dug-up roads waiting to be re-laid and so on. These inconveniences have often also led to tragic outcomes.

Planning conundrum
Right from the start, the SWD project was met with equal parts enthusiasm and scepticism. Among the latter is Zoyab Kadi, senior architect and design head at RVS Padmavathi College, who expressed concern about the manner in which works were taken up. “The intention of a stormwater drain is to lead the rainwater towards some waterbody, for which you need slopes and gradients, so whether that is being looked after is of great concern. The lack of either of these is what usually leads to waterlogging and flooding. I’m very sure the designs were made by very competent people; my only concern is how well it is being implemented. So that is something we’ll have to wait and see,” he said.

General opinion about the project has been that it could have been started at least three-four months earlier, which would have prevented this last-minute scramble in the midst of the occasional downpour. But there are also questions raised about the prioritising of the project, in the sense that low-lying areas that are more vulnerable to flooding could have been taken up first. The people residing in these areas are often at the frontline when the city floods, Zoyab says, questioning why they weren’t prioritised.

Climate crisis
Chennai has been alternating between cycles of droughts and floods for the past several years. Manushi Jain, director/co-lead of Sponge Collaborative, attributes this to the city’s rampant expansion over the past two decades, taking over farmlands, wetlands, low-lying areas, and forests, which previously served as natural reservoirs during the monsoons and recharged the aquifers during the summers. “Chennai can no longer afford to ignore the region’s remnant and still intact natural systems,” Manushi says, adding, “They are integral to making Chennai more liveable — by maintaining the hydrological cycle, reducing the heat island effect, creating habitats for birds and animals, and offering a number of recreational and cultural benefits.”

With climate change posing an increased risk of extreme weather events like drought and flooding, the push for sustainable development has been getting stronger. A few months ago, the GCC released the Chennai Climate Action Plan on its website. Drafted in collaboration with C40, a worldwide network of 100 cities coming together to combat the climate crisis of which Chennai is now a part, the document features floods and storms, heat and water scarcity, and sea level rise as “identified climatic hazards for Chennai based on prioritisation of past and future trends,” and predicts that 100m of its coastline could be underwater in the coming five years.

In a city that remains dry for eight months of the year, the water could be used to recharge groundwater tables, preparing the city for the long, dry summer that lies ahead. “Chennai is a water-starved city. We’ve been wasting our water all these years. This scheme will hopefully recharge groundwater tables, especially around lakes and riverbeds. It will also be of great help to vulnerable areas that are close to waterbodies. How far this works is yet to be seen,” Zoyab said. He did, however, raise concerns about what he termed the one-size-fits-all approach, where the cross-sections are of the same size, regardless of the size of the road.

Looking beyond SWDs
And yet, the city needn’t depend only on stormwater drains to prevent waterlogging. Manushi laid great emphasis on the Sponge City approach, which focuses on creating sponge landscapes that can absorb water during heavy rain and recharge the groundwater table. For the Third Master Plan, Sponge Collaborative has been working on the Adyar Basin, where the river basin is elevated as an integral planning unit. The idea here is to provide a strong ecological foundation to the city’s urban expansion ensuring climate resilience, sustainability and inclusivity.

“We wanted to emphasise the importance of regional planning by promoting strategic basin planning and water-sensitive urban design. Strategic basin planning is a coherent multidisciplinary approach to managing basin water resources and their users in order to identify and satisfy social, economic and environmental priorities,” she added.

While river basins act as great sponge landscapes, they needn’t be the only options. Playgrounds, parks and other open spaces in the city could also be used to serve as sponge landscapes, and they cause a lot less inconvenience to the public. Citing the example of Tokyo, where playgrounds were dug one or two feet lower into the ground, converting them into ponds during the monsoons, Zoyab asks why the same couldn’t be done in Chennai. “Imagine our cricket grounds being lowered by one foot, how much water they could absorb during the monsoon. We have a lot of playgrounds in schools and other open spaces that could be used as sponge areas to absorb water. These are simple methods that can still be implemented,” he adds.

Less than a month into thisyear’s monsoon season the stormwater drain project has brought up an interesting mix of results. While indicative of a shift in thinking, there is much that can be improved. And once the monsoon has receded, the Greater Chennai Corporation will have 482 km of road laying to do, so the road ahead is, quite literally, a bumpy one.

Sponge Collaborative’s Estuarine Transect in Adyar; pictures of
waterlogging due to the recent spells in the city
| R Satish Babu, P Jawahar, Martin Louis, Ashwin Prasath

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