One of the major reasons that Chennai flooded as badly as it did in December 2015, is because all of its natural drainage systems – primarily the Ennore Creek – were choked.

Explainer Why Chennai needs to speak up to save the Ennore creek
news Environment Thursday, September 29, 2016 - 10:38


The floods which devastated Chennai last year, unearthed the massive morass that is the story of practically every metropolis: encroachment, especially of water bodies, and unplanned building creating an ugly cocktail of disaster when the skies pour.

That was also the story of Chennai.

One of the major reasons that Chennai flooded as badly as it did in December 2015, is because all of its natural drainage systems – primarily the Ennore Creek – were choked, and the incessant rains kept adding to the volume of water that was draining out painfully slowly.

Ennore Creek wasn’t killed overnight. What made its death invisible was the fact that it occurred over three decades, by acts of commission and omission.

Located to the north of Chennai, the Ennore Creek drains two rivers – the Araniyar and Kosasthalaiyar which meet at Ennore Creek before flowing into the Bay of Bengal at Mugathwarakuppam. In many ways, it is more important than the two rivers Adyar and Cooum which were the centre of focus during the floods and after.

Here are five major blows that figuratively broke the backs of the Araniyar and Kosasthalaiyar:


After the North Chennai Thermal Power Station (NCTPS) was set up, 1990s onwards, hot water has been discharged into the creek. The plant devoured the salt pans surrounding it, to set up a flyash pond. Flyash from the pond leaked into the creek and deposited silt into the river. Ash pipelines laid on platforms further blocked the flow of water. Some of the ash slurry leaked into the river adding even more layers to the debris in the river.

Ash spilling from leaky pipelines have choked the river and the Canal

Dumping of earth:

The two ports located in the Ennore Creek region – Kamarajar Port and Kattupally Port have severely affected the salt pans, wetlands and mangroves in the region.

The Kamarajar Port, earlier known as Ennore Port, dumped a lot of sand dredged out from the ocean onto the Athipattu salt pans. The Chettinad Iron Ore and Coal yard now stands on the Athipattu salt pans.

Chettinad coal yard in 2016

Ennore Thermal Power Station has dumped earth into Buckingham Canal.

In the mid-2000s, the Vallur mangroves disappeared under the power plant set up by NTPC and TANGEDCO. The flyash pond of the power plant has prevented several streams of the Kosasthalaiayar before they can reach the Creek.

Bridges and Roads:

The first bridge to be constructed was a railway bridge, connecting Chennai to areas north of the city. But, the area around the pillars was dredged to restore the earlier water-carrying capacity of the river.

ETPS is planning to construct a conveyor belt with many pillars inside the river. There is also a broad mud road blocking about 100 metres of the river.

Construction debris betewen the columns of the bridge

Totally, there are 11 bridges and roads in the area, blocking the rivers and streams, and reducing the depth of existing channels. Meaning, that the rivers simply cannot handle their natural capacity of water. When the capacity is in excess of the normal rains and water flows, the result is there was all to see: Chennai, December 2015.

What can be done to save it?

It is crucial that all these blockages be removed. However, ports and power plants are general considered facilities of national importance and cannot be wished away. However, some of the lost wetlands, salt pans, and mangroves can be regenerated.

Mangroves being destroyed

One of the steps that can be taken is to remove the flyash from the creek and wetlands, and formulate a long-term solution to dispose of it in an environmentally responsible manner. The Buckingham canal too, needs to be de-clogged by removing flyash.

Desilt all the rivers, Buckingham Canal and feeder canals like Captain Cotton Canal, Otteri Nullah, Kodungaiyur drain.

Stop all further construction on saltpans, mangroves and other wetlands in the Ennore region in line with the Madras High Court's directions prohibiting conversion of wetlands.

(Images courtesy: David Grosman)

(Map courtesy: Pooja Kumar)

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