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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. 
Down to earth

Ecologically subsidised city

Kolkata s ecosystem can educate one about living creatively with nature


The city sewage treatment system of Kolkata, a city of 14 million

The East Calcutta Wetlands originally formed as a spillover basin of the Bidyadhari River, and has now been converted into a vast derelict swamp with the cessation of tidal influx.


Soil detox from Kolkata wetlands

A team of Kolkata-based researchers mapping the microbial population of the East Calcutta Wetlands (ecw), has isolated 22 easy-to-culture strains that can help clean up toxic soil and water


Heavy metals polluting Kolkata's groundwater

Heavy metals are seeping into Kolkata's groundwater from Dhapa, its waste dumping ground on the eastern fringe of the city.


Bengal wetlands treasure troves of microbes

A landfill in the East Kolkata wetland area has emerged as a treasure trove of useful microbes that could be tapped for various biotechnological purposes.


Research Paper:

DesignWastewater-Fed Aquaculture in the Wetlands of
Calcutta - an Overview

Bunting, S.W., Kundu, N., Punch, S. and Little, D.C. East Kolkata wetlands and livelihoods: workshop proceedings. Stirling, UK: Institute of Aquaculture [Working Paper]

Ghosh, D. 1985a. Dhapa Report. From disposal ground to WAR (waste-as-resource)field. Submitted to Calcutta Municipal Corporation (Preliminary Draft). Government of West Bengal, India. 32p.

Ghosh, D. 1985b.Cleaner Rivers. The least cost approach. A village linked programme to recycle municipal sewage in fisheries and agriculture for food, employment and sanitation. Government of West Bengal, India. 32p.

Ghosh, D.& S.Sen. 1987. Ecological history of Calcutta's wetland conversion. Environmental Conservation 14(3):219- 226

Gunnerson, C.G.1984. Research and development in integrated resource recovery (an interim technical assessment). UNDP project GLO/80/004.

IWMED.1986.Growing vegetables on garbage. A village based experience of city waste recycling. Institute of Wetland Management and Ecological Design, Calcutta, India. 33p.

Maltby, E. 1986. Waterlogged wealth. An Earthscan Paperback, International Institute of Environment and Development, London, England. 200p.

Mitsch, W.J. and J.G.Gosselink. 1986. Wetlands Van Nostrand Reinhold Company, New York, U.S.A.399 P.

Rybczynski, W., C.Polprasert & M.McGarry. 1978. Low-cost technology options for sanitation: a state-of-the art review and annotated bibliography. IDRC-102e, International Development Research Centre, Ottawa, Canada. 184p.

WBSLUB. 1984. Report of the fact finding committee set up by the West Bengal State Land Use Board on the problems of paddy-cum-brackinshwater fish/prawn cultivation and forcible conversion of paddy lands into fisheries in parts of 24- Parganas District. Director of Land Records and Surveys, West Bengal, India.

  1992: Court proceedings begin with the first writ petition By PUBLIC (People United for Better Living in Calcutta), a Kolkata based NGO and has led to repeated judgments prohibiting changes of land use in the Waste Recycling Region of the wetland area.

1995: 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.

1995: 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.

1996: 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.

2002: East Calcutta Wetlands has been designated as a Ramsar Site 

2004: The tanning association formed.  The association of the tanners approached the state government to manage and operate the common effluent treatment plant.

2005 East Calcutta 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.

2005: The management of the Tannery plant was transferred and it was with around 40 relocated tanners. The present charges are Rs 14 per kl of treated effluent.

2006: 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.

2006: PUBLIC filed a petition 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).

2006: The tannery association emphasized that Dalmiya had failed to construct the common effluent treatment plant, as promised. ”WWF, other environmental groups, MoEF protested the action.

2007: 433 of the 550 tanners have been allocated land at the Bantala Leather Complex and 125 tanners have already started operations.

2008: The state environment department is “in principle” against the Calcutta Municipal Corporation’s (CMC) plan to set up a water treatment park on the East Calcutta Wetlands, where the high court has banned construction activities.

2008: 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).

2008: Calcutta High Court on Wednesday 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.

2009: The Supreme Court on Monday 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. The state will have to respond at the next hearing on May 8.

Arijit Majumdar
Principal Consultant
Creative Research Group

Dhrubajyoti Ghosh
Institute of Wetland Management and Ecological
Under The Administrtive Control Of Department Of
Environment, Govt. Of West Bengal B4, L.A. Block,
Sector- Iii, Salt Lake, Calcutta - 700 098
West Bengal, India


Subhash Dutta
Howrah Ganatantrik Nagarik Samiti
West Bengal
Phone: 91-33-26603526, 26501484

Centre for Environmental Management and Participatory Development (CEMPD)
HB-150/Sector-III, Salt Lake City,
Kolkata-700 106, West Bengal
Phone: 91-33-23585832 
Email- cempd@yahoo.co.in,

People United for Better Living in Calcutta
11,Hindusthan Park
 Calcutta - 700029
West Bengal
Tel: 91-33-24642921, 33-22495290
Email: - public@cal2.vsnl.net.in
Website: - http://www.allindia.com/public

Shri Harish N. Salve
Solicitor General of India
Res. 42, Poorvi Marg, Vasant Vihar,
New Delhi
Tel. Res. 91-11-26159170, 26141217, 26142218
Mobile: 9871808080
E mail: hns3007@yahoo.com hsalve@sapta.com