The wetlands to the east of Kolkata comprises of many water bodies from north and south 24 Parganas. The hydrological setup of these wetlands is completely different from any other wetland in India. There is no catchment for these water bodies and perched aquifer is found to occur below these water bodies at depth greater than 400 feet.
These wetlands are well known over the world for their multiple uses. The wetlands are man made and the system of wastewater treatment is the largest in the world. It has saved the city from constructing and maintaining a wastewater treatment plant. The wetland comprises of intertidal marshes including salt marshes, salt meadows with significant waste water treatment areas like sewage farms, settling ponds and oxidation basins.
In these wetlands a wise use of ecosystem is done whereby 250 million gallons of sewage of the city flows to these water bodies and is used for traditional fishing and agriculture. It is the largest sewage fed fishpond in the world. Currently there are about 300 large fish farms and ponds covering a total area of 3,500 ha. Some very large ponds have an area of 70 ha. Per day about 13,000 tonnes of fish and 150 tonnes of vegetables are produced in these wetlands.
The total area of the East Kolkata Wetlands is 12500 ha of which approximately 45.93 % is the water body and 38.92 % is the agricultural land. The remaining portion is occupied by urban and rural settlements and sites for garbage disposal.
For the usefulness of the ecosystem of these wetlands of east Kolkata, they have been designated as a Ramsar Site in November 2002. In August 2002, 12,500 hectares of these wetlands was included in the ‘Ramsar List’ making it a ‘wetland of International Importance’. (The Ramsar Bureau List was established under Article 8 of the Ramsar Convention.) The two most important threats in these wetlands are that of encroachment due to urban development and siltation. The constant change of land use pattern has affected the ecology of these wetlands. Many large pisciculture ponds have been converted to paddy fields. The industries in the adjacent areas have made unauthorized connection to the sewers to empty their untreated wastewater. The sewers on the other hand empty the water into the channels that later on join the wetlands. This is causing a deposition of the heavy metals in the canals and ultimately the quality of fish and vegetables produced in the wetlands is far below the edible standard.
In 1992, a Kolkata based NGO, People United for Better Living (PUBLIC) in Calcutta filed a petition in the HC against the changes of land use in the Waste Recycling Region of the wetland area.
This case is still under the consideration of SC of India. The followings are some of the highlights of court verdicts, government and people actions
PUBLIC filed PIL in the SC.
PUBLIC had accused leading government officials of contempt of court, A criminal offence, for not having adequately safeguarded the wetlands, particularly with respect to the leather complex and several other minor encroachments.
A report was prepared by the National Environmental Engineering Research Institute that detected that presence of chrome-based tanning among Kolkata tanners, with inappropriate wastewater drainage and collection systems, was causing serious environmental, health and hygiene problems.
Supreme Court order directed these and other inner city tanners from Tiljala, Topsia and Pagla Danga districts to shut shop and relocate to the Bantala Leather Complex, 15 km away from Kolkata as a judgement of M.C. Mehta Vs Union of India
The judges expressed their dissatisfaction over the inability of the Ministry of Urban Development to specify the time frame for amending the buildings by laws. DJB was fined Rs 2,500 for not submitting the report on the leaking water pipes.
The HC took up the issue of protecting the natural lakes of Delhi during this hearing. The bench observed, “We understand that natural water bodies that exist in Vasant Kunj and Prasad Nagar areas would vanish if not taken care.” The MCD was directed to submit an affidavit with regard to steps taken to protect these water bodies. As a prelude the court directed the DJB, MCD and the NDMC to collect information on the water bodies in Delhi.
East Kolkata Wetlands was designated as a Ramsar Site.
The tanning association formed. The association of the tanners approached the state government to manage and operate the common effluent treatment plant.
East Kolkata Wetland Management Act was formed. The act has the power to demarcate the boundaries of the wetlands as well as to take measures to stop, undo or prevent any unauthorized development project or illegal use of the wetlands.
East Kolkata Wetlands Conservation and Management Bill, 2006, which aimed at including 12, 571 hectares of land into the East Kolkata Wetlands, was passed. Any illegal construction will be penalized up to 1lakh according to the bill. The state government decided not to dislocate 50,000 villagers who were already living in the five moujas that had been included in the wetlands. According to the bill all the pre existing constructions within the wetland had to be demolished.
PUBLIC filed another petition in the HC alleging that KMC had selected an area for its water supply project at Bointala in Dhapa which fell under the purview of the East Calcutta Wetland Management Act (2006).
The tannery association emphasized that Dalmiya had failed to construct the common effluent treatment plant, as promised. WWF, other environmental groups and MoEF protested the action.
433 of the 550 tanners have been allocated land at the Bantala Leather Complex and 125 tanners have already started operations.
The state environment department was “in principle” against the Kolkata Municipal Corporation’s (KMC) plan to set up a water treatment park on the East Kolkata Wetlands, where the high court has banned construction activities.
An order was issued barring local authorities (municipal corporations, Panchayat, etc) from issuing licenses or sanctioning building plans for commercial activity without a clearance from the East Kolkata Wetland Management Authority (EKWMA).
Calcutta High Court granted conditional approval to Kolkata Municipal Corporation (KMC) to set up a water treatment plant in the east Kolkata wetlands. While giving the nod, the division Bench imposed strict conditions, including compensatory greening, creation of water bodies, minimization of ecological damage and specifying the quality and nature of materials to be used. The court also appointed a three-member committee (comprising two former university vice-chancellors and a professor) to monitor and report on the KMC’s compliance with the restrictions.
The Supreme Court admitted the matter filed by Kolkata's non-government action group PUBLIC, objecting to Kolkata Municipal Corporation's plan to locate the facility of Rs 100-crore water treatment plant at Dhapa inside East Kolkata Wetlands, a Ramsar site.
In March, scooping out silt from the canals of EKW, that carry 1,300 million litres of wastewater into the bheris (
everyday has made them deeper, changing the natural gradient and obstructing the flow into some parts. Fish production had dropped in these areas.
In March it was found that about 33 water bodies in the Ramsar-protected East Kolkata Wetlands were filled illegally for the construction of the Newtown-Rajarhat Township. A letter (No. Hidco/planning 13/99) dated 19 November, 1999, written by the erstwhile managing director of Hidco, West Bengal, Mr Sanjay Mitra, to the secretary of the fisheries department, sought permission for relaxation of the provision of Inland Fisheries Act, 1984 and West Bengal Inland Fisheries (Amendment) Act, 1993 for filling up of water bodies for the implementation of the New Town Calcutta Project. The 33 water bodies that were filled by the Hidco without permission from the fisheries department ranged from 6.05 cottahs to 114.95 cottahs.
The government prepared a draft management plan to conserve East Kolkata Wetlands (EKW). The state government has been forced to prepare the draft plan after the Centre recently imposed a ban on discharging sewerage into any kind of water body by framing a new Wetland rule. The new rule has left the state in real trouble as the EKW serves as the natural sewerage treatment plant for the city.