Calcutta's Wetlands

Can you believe that chaotic, crowded Calcutta is home to 200 species of birds? But we need to fight to keep it that way. Here is the remarkable story of

The Calcutta Wetlands

Calcutta has had more than 300 years of haphazard, unplanned, chaotic growth. Its population has exploded beyond its infrastructure. It is a city bursting at its ageing seams. Yet it is still a city vibrant with animal and plant life. Within its limits, the city can boast of 10 species of mammals, 200 species of birds, 15 species of reptiles, 13 species of amphibians and 40 types of butterflies! One of the reasons for the city’s abundant animal life is the wetlands in the city’s backyard.

Only a few decades ago the Calcutta wetlands covered an area of 20,000 acres. Then the city’s planners decided to build a satellite township called Salt Lake, by filling up about 10,000 acres of the ponds and marshes that made up the wetlands. In the last decade or so, the bustling township has attracted private promoters to fill in more wetland areas surreptitiously. Several boating resorts and picnic spots as well as a couple of amusement parks have made use of some of the ponds. Also, the government had plans to reclaim more of the wetlands for even more buildings. As they stand now, the Calcutta wetlands are a dwindling 750 acres or so of marshes and ponds, also known as bheris.

The entire waste and drainage water of Calcutta runs through a system of channels going through the wetlands. The wetlands provide the city of Calcutta with the invaluable service of recycling all its sewage through a natural process of oxidation, radiation, bio-degradation and fisheries.

The Calcutta wetlands are used for commercial pisciculture (fish farming), agriculture (growing rice and vegetables) and horticulture. They are also used for garbage dumping and composting and disposing of the city’s solid wastes. So they provide a livelihood for a large number of Calcutta’s population.

If the Calcutta wetlands are not preserved and maintained, the cost to the city would be very high. I can already think of some of the immediate effects of the loss of the wetlands:

• The destruction of the wetlands would mean a loss of beauty and open spaces in a city that does not have enough of either.
• Air pollution would increase to noxious levels, causing more respiratory problems for the city’s population.
• Without the wetlands, Calcutta’s water quality would deteriorate, become harder and more filled with harmful minerals. The ground water would become unpredictably saline. The water would become unfit for human consumption and the river Hoogly would need to be tapped and treated for the city’s population.
• During the monsoons, the city would lose its natural drainage and there would be tremendous flooding leading to an increase in health hazards like malaria, gastroenteritis and cholera.
• Costly pumping stations would have to be set up for drinking water; expensive sewage treatment plants would be required and new garbage disposal sites would need to be earmarked.
• The cost of fish and vegetables would rise. They would need to be brought into the city from distant places because the wetlands could no longer provide Calcutta with its daily fish and vegetables.
• Many poor people would lose their livelihood.
• Innumerable animals and plants would lose their habitat and die. The city of Calcutta would lose its pulsating plant and animal life.