Kolkata Metropolitan area consists primarily of three Municpal Corporations (Kolkata, Howrah and Chandannagar) and several urban local bodies, 39 in numbers within an area of 1851.41 sq. km. It covers six districts of the state. Kolkata is one of the largest urban agglomeration of the country with a population of 14.72 million (1901 census) and a density of 7950 persons per sq. km. The city is spread linearly along both the banks of river Hooghly.

The Kolkata Metropolitan Area (KMA) is primarily served by (a) surface water from the perennial Hooghly river and (b) ground water source. Out of these water from river Hooghly was treated and supplied to a limited area of KMA prior to 2007 through treatment plants while the majority of KMA had to depend on ground water source.

The projected population of KMA in the year 2025 is 21.07 million and the corresponding water demand will be 681.4 MGD. Considering 15% UFW, the required treated water production should be 783.6 MGD during 2025. The demand for 2039 would be 840 MGD.

The above water demand needs to be met by enhancing existing water resources with greater focus on surface water due to its economic and environmental sustainability.

Prior to taking up the Water Supply projects under Jawaharlal Nehru National Urban Renewal Mission (JNNURM), the installed surface water treatment capacity in KMA was 421.60 MGD. So there would be a shortfall of about 418.40 MGD. In order to meet the shortfall and also in order to reduce the dependence on Ground Water source from hygienic and environmental consideration, 210.19 MGD Surface Water Treatment is being proposed under the robust initiative called JNNURM.

Under the subhead Urban Infrastructure and Governance (UIG), 21 Water Supply projects have been taken up in 28 municipalities within KMA with a total project cost of Rs. 2676.52 crores. 35 % of this project cost is being contributed by the Govt. of India amounting to Rs. 936.78 crores. The balance amount of Rs.1739.74 crores would be contributed by the State Government out of which Rs. 284.02 crores has been contributed by KMDA. The much awaited endeavour has come as a boon to the population that is benefited.

Some of the projects have already been completed while few others will be implemented within next one year.