Record rainfall in Chennai - 374 millimetres in 24 hours, surpassing a record set in 1901 - has submerged large parts of the city. Beyond the Chennai district, too - all along the coast to southern Andhra Pradesh - communities have been stranded by flood waters; over 250 people have died. Factories and schools have shut, ground floors of apartment buildings are underwater, and the airport has been closed till December 6. Photos circulated widely showed the water lapping against the banisters of the bridge across the Adyar river. The citizens of Chennai have risen to the occasion inspiringly, opening their homes to strangers and working to provide food and shelter for those affected. The state government has claimed that over 200,000 packets of food have been distributed. The army, navy and air force have all joined the rescue effort.
However, none of this should take away from a clear-eyed examination of whether the torrential rain needed to have had such a devastating effect. It has been reported that authorities were warned days in advance of the possibility of unusual amounts of rain, following the development of a cyclonic circulation in the Bay of Bengal just off north Tamil Nadu. Not only were preparations following this warning minimal, but it has been additionally reported that almost 30,000 cusecs of water were actually released from the Chembarambakkam lake on the outskirts on Wednesday, which may have flooded new areas of the city. Questions will have to be asked of the state government and the Chennai Corporation in order to determine whether they bear any share of the responsibility. For example, the upgrade of the city's 900 kilometre-long storm-water drain system, supposed to be complete by now, has been delayed.
While these floods are unprecedented in their consequences, Chennai has already suffered from one previous bout of flooding this season, again following a greater-than-normal cloudburst. Such extreme weather events are becoming more common, and climate scientists view them as an effect of global warming. This should serve as a salutary reminder to India's negotiators at the Paris climate talks that this country is more at risk than most to man-made climate change, and they should go the extra mile to achieve a compromise in the United Nations-sponsored conference - widely recognised as the last, best chance to slow the acceleration of global warming. But this is an indictment, also, of unplanned urban growth. Chennai is a city built on swamps, marshes and waterways. But those natural drainage patterns have clearly been rendered ineffective by city planning that does not provide for emergencies of this nature. The drain-off system in Chennai, a city of millions, was originally planned for a population of 650,000. The Cooum and Adyar rivers are rarely dredged and their floodplains have been encroached upon. A recent study in Current Science estimates that more than half of Chennai's wetlands have been rendered useless by development; the 150 water bodies in the city serving as catchment areas have been reduced to 27. Dramatic reductions in green cover - almost wiped out in some municipal wards - mean that the ground cannot retain water; this increases water run-off by almost 90 per cent in some areas. The present government's focus on "smart cities" is all very well. But these are more basic amenities that must be put into place first. A bigger challenge now awaits the authorities in Chennai. The devastation caused by the rainfall will require redoubled efforts to bring civic infrastructure back to normal and adequate health care measures will have to be initiated in earnest to prevent the spread of disease likely after such a natural calamity. It is also time to question India's priorities when it comes to its poorly planned urbanisation.