The Future of Resilience

With Groundwater Drying Up, Thirsty Calcutta Eyes Its River

Kolkata’s River is the target of a cleanup effort, in part because it may soon supply the city’s drinking water. Photo credit: Avishek Mitra

As the sun sets over Kolkata every evening, young couples, students and elderly residents stroll an immaculate, freshly paved Hooghly riverfront. On either side of the River Hooghly, a 260-kilometer distributary of the Ganges River in West Bengal, the dirty, rundown banks that line Kolkata and its sister city Howrah are finally getting a facelift. Just a few years ago, this stretch of river was fetid, polluted and neglected. It had become unsafe for strolling at any time of day.

It’s now the focus of a massive cleanup effort, and not just to make it look pretty. With groundwater quantity and quality around Kolkata becoming unreliable, the authorities here have decided to switch completely to surface sources for the city’s drinking water. That means millions in this sprawling city will soon be drinking the very water they see lazily churning through their city every day.

A large part of Kolkata Metropolitan Area (KMA) is currently served by groundwater pumped up from an aquifer deep below the city. This water travels through tube wells and into a network of pipelines and reservoirs before reaching the city’s taps. A recent study by Geological Survey of India and Geo-Scientific Studies, however, found that the water levels in these groundwater sources are dropping fast. Because the city is drawing water from the aquifers more rapidly than they can recharge themselves, the KMA is eager to cut the city’s reliance on them.

“It is… high time that necessary plans be sorted out to switch over to the surface water system,” one KMA official tells Next City.

In its earliest days, Kolkata was dependent on the River Hooghly for its drinking supply. The Great Tank, known as Lal Dighi, in the city’s heritage hub of Dalhousie Square, was deepened and extended in 1709 to ensure a good supply of water for the garrison of old Fort Williams. Colonial Kolkata later developed around that area. According to the KMA, between 1805 and 1836, the excavation of large water tanks in Cornwallis Square, College Square, Wellington Square and Wellesley Square, to name a few, kept the city hydrated during the days of British rule.

Now, according to Rajat Chatterjee, director general of operations for the Kolkata Metropolitan Development Authority (KMDA), the days of surface water providing the vast majority of the city’s drinking water are about to return. “Under the JNNURM [Jawaharlal Nehru National Urban Renewal Mission, a massive city-modernization scheme launched by the national government] we got access to funds and, under this mission, the groundwater source is being replaced by the surface water source. The water is now being treated in the jetty-mounted pumping stations.”

The change in policy has sparked an infrastructure boom. Among the major Water Supply Schemes completed to meet the challenge is an augmentation of the age-old Palta Water Works. The capacity of the plant, located about 20 kilometers north of Kolkata, has been augmented, and construction of an additional underground reservoir at Tallah in north Kolkata is also a part of the project. In Kolkata’s sister city, Howrah, the Howrah Water Treatment Plant has been constructed, along with several other new water-treatment plants nearby.

With groundwater depletion around Kolkata hitting critical levels, the River Hooghly is going from eyesore to savior as the authorities gear up to harness its waters for the city’s taps. If executed correctly, one ecological pinch-point at the aquifers below the city could lead to a green renaissance at the surface above.

Tags: resilient citiesindiacalcuttawaterwaysdrinking waterbeautification