Danger signals for Chennai's waterbodies

Chennai, July 1: Chennai City and its suburbs once boasted of over 600 small and big waterbodies but now a majority of them have been gradually destroyed due to a combination of hectic urbanisation and anthropogenic interferences.

The city's important waterbodies include the Adyar Estuary, Adambakkam lake, Ambattur Lake, Chitlapakkam Lake, Ennore Creek, Korattur Swamp, Koyambedu Marshland, Madhavaram and Manali Jheels, Pulicat Lake and Vyasarpadi Lake besides Buckingham Canal, Cooum and Adyar River and Otteri Nullah.

''Since 1960, we have systematically destroyed almost every single water body within the city and suburbs. The few remaining ones and wetlands continue to be under daily assault and are seriously threatened,'' Madras Naturalists Society K V Sudhakar told sources.

The wetlands played important roles as groundwater rechargers and natural drain-off mechanisms during monsoon and as natural habitat for fish, birds and other aquatic life, he pointed out.

The wetlands were also a haven for bird-watchers and ornithologists. For instance, the Adyar Estuary once attracted more than 120 species of birds.

Even the doyen of Indian Ornithology, Dr Salim Ali, had stressed the need for protecting the creek not only for the sake of birds but also for the benefit of human beings.

Sadly, only a small portion survived today and inlet and outlet channels for seawater clogged, Mr Sudhakar said.

''Besides, many scrub jungles across the city are slowly being either destroyed or turning the area into modern plantation'', he pointed out.

He said ''if you make a scrub jungle into a modern plantation, rare birds such as Wren Warbler, Bablers, Sun birds and Bul Bul will not nest in these areas.''

Interestingly, Pulicat Lake, the second largest in the country, which extended to 460 km had been reduced to 350 km in few decades leading to reduction in aquatic population to a large extent, according to a study by a team of experts under Loyola Institute of Fornturn Energy (LIFE) has revealed. ''Earlier, the depth of the lake used to be four metres but now it is 1.5 metres.

Reduction in volume of water had led to lower aquatic life though the water quality remains the same. This has greatly affected the fish catch,'' Project Co-ordinator Selvanayagam said.

The report suggested desilting the shores of the estuary to help inland water flow for better aquatic life. ''Ways and means of increasing the biodiversity in the area should be suggested,'' the report said.

Naturalists pointed out the last wetland that died on the pedestal of development was the Koyambedu Marshland. About 15 years ago, the area used to have a lot of wild growth attracting a large number of birds.

During monsoon, rainwater used to get stored in the marsh and it helped in maintaining the groundwater table in the western parts of the city.

A few years ago, the marshland was taken over by the government for housing vegetable and fruit markets and a bus terminus.

Some experts believe that alternatives lie within and around Chennai.

S Janakarajan, Professor at the Madras Institute of Development Studies (MIDS), said the peri-urban belt around Chennai has 600 to 800 tanks, ponds, lakes and other waterbodies that have been neglected or are in a state of disrepair.

Worse, many of them have been destroyed forever by land-grabbing real estate developers. As a result, not only have water sources been destroyed, but the recharging of groundwater has been affected.

Prof Janakarajan feels that much more ought to be done within the city and its immediate hinterland before Metrowater seeks water from elsewhere.

UNI