The West Bengal government began pumping material dredged from the Hooghly into the Salt Water Lakes east of Kolkata to create land for a new township. The area was then a low-lying expanse of saltwater lakes, marshes and fishing grounds, while the city was looking for more land to accommodate its growing population. The government brought in a Yugoslav firm and used dredgers, barges and pipelines to pump sandy slurry into the wetlands. Over the next few years, the reclaimed land was developed into what is now Bidhannagar, better known as Salt Lake.The project began on April 16, 1962, when then West Bengal chief minister Bidhan Chandra Roy switched on a pipeline carrying dredged material from the Hooghly into the Salt Lake area. The idea was to reclaim the low-lying Salt Water Lakes and create a planned township on the eastern edge of Kolkata. The government had begun examining the area as a possible site for the city’s expansion in the 1950s.A Dutch engineering consultancy had surveyed the area in 1953, and the government subsequently acquired land for the reclamation project. The engineering challenge was considerable. The proposed township stood on land that was largely below the level considered suitable for urban development, so the area had to be filled and raised.How Kolkata created land from a lakeThe government awarded the reclamation work to the Yugoslav firm Invest Import after a global tender.Dredgers were used to extract material from the Hooghly, which was then transported towards the Salt Lake area through a system involving tugboats, barges, boosting stations and pipelines.The material was pumped into sections of the wetlands. As the solid matter settled, excess water was drained before more material was added. The process gradually transformed the shallow lakes and marshes into usable land. The reclamation covered about six square miles and was carried out in stages. The first sector was completed in 1965, followed by Sectors II and III in 1969.From wetlands to a planned townshipThe first residents moved into the new township in March 1970, according to historical records of Salt Lake’s development. The area was initially planned largely as a residential township, with roads and sectors laid out in a planned pattern. Over time, other parts developed into commercial and institutional centres.The township was named Bidhannagar after Bidhan Chandra Roy. The name Salt Lake, however, continued to be widely used. A 1973 Calcutta Gazette notification officially changed the name of Salt Lake City to Bidhannagar. What had started as a land-reclamation project eventually became a major urban centre on Kolkata’s eastern side.What was there before Salt Lake?Before the reclamation, the area was not simply unused land waiting to be developed. The Salt Water Lakes were part of Kolkata’s extensive eastern wetlands. The low-lying area contained water bodies, marshes and fishing grounds, with communities depending on the wetlands for pisciculture and other livelihoods. The wetlands also played a role in the city’s natural drainage system.Reclaiming the area therefore brought a dramatic change to the landscape. Water and marshland were gradually replaced by roads, houses and planned neighbourhoods. The transformation also had an environmental cost. Research into Kolkata’s urban ecology has documented the loss and alteration of large areas of wetlands as the city expanded eastwards.The city built on reclaimed landMore than six decades after the first pipeline was switched on, the landscape bears little resemblance to the Salt Water Lakes of 1962. Bidhannagar now has residential neighbourhoods, offices, educational institutions, markets and major commercial areas. The wider Salt Lake area has also become an important business and technology hub in Kolkata.
