Two pipes carrying potable water from the Tallah pumping station to the city will be functional by this weekend, officials of the state public works department and the Kolkata Municipal Corporation said.
A KMC official said the two new pipes, built as replacement of two older ones that had to be dismantled for the construction of the Tallah bridge, are of 48-inch diameter each.
The older ones were 30- inch diameter each.
There are five other pipelines running parallel to the Tallah bridge that were used to supply potable water from the Tallah reservoir after the two old pipes were demolished.
The pressure on the five pipes will be reduced once the new ones are put to use.
“Since the diameter of the new pipes are way more than the previous ones, we have decided that one of the two new pipes will be made operational and the other will be left for future use when the demand increases,” said a senior Kolkata Municipal Corporation (KMC) official.
The addition of the new pipes will help engineers carry out periodic repairs on some of the older pipes without disturbing the supply of water, officials said.
The work of constructing two separate ducts — along the Tallah bridge — to carry each of the two pipelines has been completed and the pipelines will be now connected to the main network within the next few days, officials said.
About 2.5 million people from Sinthee on the northern fringes to Bhowanipore in the south get water from the Tallah pumping station.
The new pipelines will help a large majority receiving potable water across parts of north and central Kolkata, senior officials of the KMC said.
The reconstructed Tallah bridge, built at an estimated cost of Rs 540 crore, was inaugurated in September and PWD engineers have been working on ways to restore the two pipelines since then.
“Each of the two old pipes had a diameter of 30 inches. The new ones have a diameter of 48 inches. We had to build two separate ducts to carry each of the pipelines because of their size,” said a senior PWD official.
Apart from the two ends towards Shyambazar and Chiria More, a part of the Tallah bridge stands over railway tracks.
Engineers said the ducts had to be built very carefully so that they run along the structure without adding extra weight to the main bridge.
“The two ducts run close to a kilometre carrying water pipes of the biggest diameter in the city,” the PWD official added.
The pumping station in Tallah supplies 210 million gallons of water every day, more than half of the daily supply of 400 million gallons a day in the Kolkata Municipal area, the Kolkata Municipal Corporation officials overseeing potable water supply said.
