Why is India's Chennai flooded?

Nityanand Jayaraman BBC 4 Dec 15;

The severe flooding in Chennai again proves that India's cities are unprepared for extreme weather events like rains, droughts and cyclonic storms which are becoming more frequent and intense.

Many parts of India suffer flooding every year during the annual monsoon rains from June to September. The northeast monsoon has been particularly vigorous over southern India and more so in Tamil Nadu state, of which Chennai is the capital.

Last month was the wettest November in a century in the city of 4.3 million people. And, at 490 mm, rainfall on 1 December was the highest in 100 years.

The floods are a wake up call for India's teeming cities that were built with the expectation that the environment would adjust itself to accommodate the need for the city to grow.


The disconnect with nature is also manifest in the failure of planners, builders, administrators and even common people to fathom the sheer power of natural events.

The Corporation of Chennai and Chennai Metropolitan Development Authority are responsible for approving building plans and town planning, and for enforcing urban planning. A masterplan was prepared in 2008.

But much of the city has grown without a plan and with no regard to water flows, and without anticipating extreme weather events.

Then there's illegal construction.

As The Indian Express newspaper reports, "What may have been a tank, lake, canal or river 20 years ago is today the site of multi-storey residential and industrial structures."

There are more than 150,000 illegal structures in the city, according to the city's municipality. More than 300 tanks, canals and lakes have disappeared.

An information technology park in Chennai is flooded because it is located at a place where waters from two separate lakes converge and flow to a neighbouring creek. Many of the city's info-tech facilities are built on marshlands, water-bodies and water courses. The city's famous automobile manufacturing hubs are located in the catchment area of lakes.

No clearance

The premier engineering school IIT Madras has been accused of clearing more than 52 acres of forests, including 8,000 trees between 2001 and 2013 as part of a major construction spree that saw 39 renovation projects and new constructions in its campus adjoining a national park. Reports say none of the projects have local body approval or environmental clearance.

Plastics are another culprit. After the first intense downpour in mid-November, plastic trash washed into rivers by rainwater was pushed to sea by the swollen rivers.

At high-tide, the trash was thrown right back onto the city's beaches by the sea. The large quantity of plastics visible in the city's beach trash exposed another chink in the city's defences.

Plastics are virtually indestructible. What doesn't get washed out to sea tends to accumulate in water channels and storm water and sewage networks, impeding and even blocking flows.

Clearly, indiscriminate development and shoddy urban planning have led to the floods in India's fourth most populous city.

Nityanand Jayaraman is a Chennai-based writer and social activist

Man-made disaster: Look how Chennai built its way to floods
Chennai in 2000 to Chennai in 2015. Google Earth shows us what went wrong and resulted in the Chennai floods.
IndiaToday.in 2 Dec 15;

If there are trees, plants and open areas around, rain water will be absorbed by the Earth, but if we continue to build concrete jungles, flooding should not surprise you. Chennai floods is not a natural disaster, it is solely man-made!

Chennai claimed to be Monsoon ready even before it set in. The Corporation of Chennai ensured more than 6,200 metric tonnes of silt from the 1,860 km-long water drain network was removed. But all the apparent efforts by the corporation seems to have been flooded with the city being in a state of disaster. The problem not only lies with the inefficiency of the civic body but also the unplanned and improper development of the city.

Chennai's original terrain consists of many lakes and marshes which now is covered with innumerous buildings. Over 5,550 hectares of wetlands in the IT Corridor of Velachery, Pallikaranai and Old Mahabalipuram Road (OMR) have been developed into commercial real-estate because of which the rain water has nowhere to go and thus, settles instead on the road. There are areas in Chennai which are flooded even during normal Monsoon season.

The capital city of Tamil Nadu is going through inevitable growth and the situation will remain the same. The only way to stop the flooding is to cut on the construction process which has made Chennai populated and which acts as a hindrance to settling down of water. A cautionary plan that goes well with the original geography of the city needs to implemented by the state government when the officially recognized 'disaster zone' is to saved from the doom.

What resulted in the Chennai floods?

Filling up lowlands without proper planning, little space for stormwater to drain and heavy encroachment of the river banks was one major reason for Chennai floods.
Illegal constructions, mostly multistorey apartments and huge industries, played the next big part in making way to the floods.
Over 300 water bodies disappeared due to this.

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