Marooned once more on chennai's need for flood management

Marooned once more on chennai's need for flood management

Chennai needs integrated flood management, especially the revival of lakes and water tanks

Chennai’s date with a strong northeast monsoon ought to be a cause for all-round relief since the water fortunes of more than eight million residents of the metropolitan region depend on this weather system. Yet, the torrential rains in the meteorological sub-division, exceeding the normal by 93% in the period of four days from November 1, left tens of thousands of citizens in a state of despair. Flood waters marooned them in the rapidly growing suburban housing clusters, with many having to flee to safer places fearing a repeat of the deluge of 2015. While there have been efforts to alleviate immediate misery through the distribution of relief material in some places, the larger issue of how the city deals with flood and drought cycles remains unaddressed.

Chennai is a lower elevation coastal city with global aspirations, and very high population density. Scientific management should have ensured the preservation of the many traditional lakes and canals that existed in the city’s core a century ago to absorb the intense downpour of about 1,300 mm of rain, most of it in an annual window of a few weeks. Successive governments have allowed the mindless draining of wetlands and their conversion into expensive real estate, with catastrophic consequences. Regrettably, the great flood two years ago, which left many dead and families impoverished, has not yielded a policy course correction. If the Tamil Nadu government is serious about putting Chennai on the global map of economically viable cities, it must move beyond the creation of weak storm water drains to an integrated flood management system.

Chennai and its sprawl extending to two neighbouring districts should return to the traditional wisdom of creating tanks and lakes for water storage, and rejuvenating old silted ones, in order to harvest the floods and replenish depleted groundwater. The finding from one study in 2013 shows that 27 tanks have totally disappeared and another 400 have lost almost their entire capacity. This underscores the need to revive such natural sponges. Inviting the community to monitor the health of the tanks and lakes can keep out encroachers, who are often protected by patron-politicians. Yet, such measures can work only when the deficit of good housing and civic infrastructure is actively addressed.

Tamil Nadu, one of India’s most urbanised States, has a poor record in this area, resulting in fragile slums. New housing has mushroomed in Chennai’s suburbs, where municipal bodies are mired in incompetence and corruption. It is these localities with little infrastructure that have borne the brunt this year. Looking ahead, the priority for the State should be to integrate flood management using expert opinion and public consultation. Remedial structures should be built for existing localities. Poor waste management is exacerbating the problem by blocking drains, canals and lakes, while ill-planned road projects are cutting off flood flows. These have to be immediately addressed. The tendency to treat floods and drought as events to dole out patronage is preventing Chennai from forging robust solutions.