Flooding during heavy rains has been a thorn in Chennai’s side. Among contributory factors that can be controlled is the floodwater drainage mechanism. Studying and mastering this mechanism and getting it to do our bidding in the most efficient manner begins with preparing a master plan around it — that is echoing the thought of Janakarajan Srinivasan, former professor and director, Madras Institute of Development Studies. He is also president of South Asia Consortium for Interdisciplinary Water Resources Studies.
“We need to understand drainage system and drainage density, and come up with a master plan that links land and drainage,” says Janakarajan Srinivasan.
Delivering a speech at Anil Agarwal Dialogue 2024 in Nemli, Rajasthan on ‘Why cities flood: The case of Chennai’, Janakarajan pointed out that the high population density and decreasing per capita drainage space is taking a heavy toll on the city during heavy rains.
In fact, the Third Master Plan of Chennai Metropolitan Development Authority had discussed the question of mapping the city’s water catchment and rainwater flow patterns. “No layout approval should be allowed without a drainage master plan,” says Janakarajan. There should be an “integrated urban land and water management” approach that involves coordinated management of land and water. “This approach will help a great deal in conserving water as well as in controlling urban flood,” says the professor.
Flood-induced ravages of the city within living memory were witnessed in almost every decade in the last 50 years or so — 1977, 1985, 2005, 2015 and 2023. He questioned whether conventional wisdom followed by the State has yielded any sure-fire methods to mitigate floods and droughts. What lessons have we learnt from the past extreme events?
“Bad or myopic urban planning and a mere development-centric approach can be disastrous to ecology and environment,” he said, adding that this would eventually place enormous pressure on the entire economy, in the present as well as in the future.
Stressing on policy implementation and better monitoring mechanisms, Janakarajan suggests that the state government should rediscover and rejuvenate thousands of waterbodies around Chennai.
As most parts of the city are under “Low Elevation Coastal Zone”, a number of concrete steps must be taken now. He said that studies have shown that North Chennai is going to be very badly affected; and ECR and OMR will be more vulnerable.
The professor stressed on the need to conserve runoff water and that necessitates restoration, protection and continuous monitoring of rivers and flood plains.
There must be strict enforcement of laws against encroachments on waterbodies, rivers and streams, says the professor, adding utmost care need to be given to protection of natural wetlands, both inland and coastal.
