Better late than never
The Eastern Wetlands in Kolkata are indispensable. In 2002, the 125 square kilometres of
marshlands were declared a conservation site under the internationalRamsar Convention on Wetlands. Despite that, real estate companies
encroached on it to build luxury apartments, water parks and colleges. The state
government
finally woke up to the danger and passed a law that would
perhaps save the wetlands that have been dubbed ‘Calcutta’s kidney.’ The
ordinance bans conversion of land character. Offenders will be jailed for three years and
may also have to pay a fine of one lakh rupees.
Three-in-one bounty
Why are the wetlands so important? The obvious answer is that it helps to maintain the
ecological balance. But for Kolkata the wetland is a three-in-one blessing because it
meets three basic problems – food shortage, dearth of employment and waste
management. Almost 680 million litres of raw sewage finds its way to the wetlands
everyday. Does that sound like a perfect recipe to choke the marshes for good?
Well, in fact, the mosaic of ponds, lakes, channels and
swamps are the only sewage treatment facility the 13.3 million inhabitants of Kolkata
have. The local people have developed a unique method to use wetlands for wastewater
treatment and using the treated water for fish farming and agriculture. About 1,000
million litres of city sewage can be treated in 30 days.
How it works?
The wetlands are criss-crossed by a network of ponds (jheels), with little
vegetable plots in between. Sewage is collected in jheels and allowed to stand for
sometime. Then, the water is used to irrigate vegetables. Solid waste is dredged out and
used as compost.
The sewage is then passed to ponds filled with fast-growing
water hyacinths, which absorb the organic substance and also some of the heavy metals and
toxins. When the organic pollution is diminished by the plants, the water is used to top
up fishponds where it flows through a network of drainage channels. The ponds act as solar
reactors completing most of their biochemical reactions with the help of solar energy.
 Money from
waste
The wetlands also provide employment and food. About 50,000 people depend on them
directly: growing vegetables, making nets and rearing fish, ducks and pigs. The wet-lands
supply 10,000 tonnes of fish annually to the city.
But as Kolkata grows the volume of sewage is becoming
larger. How long can the wetlands accommodate that growth is not known. Laws like the one
passed recently can save the wetlands only when they are fully implemented. Are the
officials listening?
|
First floods in Mumbai and now in Chennai. The commom reason for the misery in
both cities can be traced to missing mangroves and random urbanisation. But Kolkata seems
to have learned from these mistakes. On November 17, 2005, the West Bengal government
passed an ordinance that will protect the Eastern Kolkata wetlands from land sharks.
Main page