Timeout for Tallah: Repair work of reservoir in full swing

Kolkata: The repairing of the century-old Tallah overhead tank, the world's largest overhead reservoir, is in full swing.

The estimated cost of repair is Rs 80 crore. This is for the first time when such a major repair has been taken up since its construction in 1909. Propped by steel columns and girders, it is 110 feet high and can store 9 million gallons of water. It was designed by WB Mac Cabe, Chief Engineer of Kolkata Municipal Corporation (KMC) and the estimated cost was Rs 5 lakh.

A heavy duty crane from France has been brought in and is being used in the repair work. All the four chambers will be repaired without the supply of water getting affected.

It may be mentioned that because of water scarcity faced by the European community who used to live in the Esplanade area in 1857 during the Sepoy Mutiny, steps were taken after the Mutiny ended to set up a water treatment plant in Kolkata, the then capital of the British Empire, so that uninterrupted water could be supplied to the areas where the Europeans used to reside. Hence, when the Tallah tank was prepared, KMC tried to ensure that supply of water to the city is not disrupted.

Accordingly, planning was done and Palta Water Works was set up in 1868. It was India's first water pumping station where raw water from river Hooghly was lifted and purified.

Tallah has a unique feature. No separate lines have been used for filling up and delivery. The pipes that fill the tank are used for delivery. Hence, the overhead tank serves as a balancing tank.

When the underground tank at Tallah is spilled over with the incoming supply from Palta Water Works, 24 km upstream of Kolkata, the surplus water is stored in the overhead tank and again when the water level in the underground tank goes down, it compensates for the loss.

Bibhas Maity, Director General (Building) Water Supply of KMC said another two years would be required to complete the repairing work.