The civic authorities have decided to prepare a digital map of the underground water pipes that were laid more than 70 years ago.
“The map will help us identify the problem areas in the water lines,” said Mayor Bikash Ranjan Bhattacharyya. “The pipes were laid 70-80 years ago but there is no map of the network.”
The Calcutta Municipal Corporation will approach the National Urban Renewal Mission for funds — Rs 1,000 crore — for the mapping as well as installation of flow and pressure monitors at strategic points in the network that supplies water to over 2.8 lakh households.
Civic records suggest that over 100 million gallons of filtered water is lost everyday primarily because of leaks in the pipes and unmonitored flow from roadside and household taps.
Almost every day, the civic water supply department gets flooded with complaints about fluctuation in pressures, leaks and uneven distribution.
“We need specific data to resolve these problems. The map will help us understand the reasons behind the fluctuation in pressures and select the right sites for booster pumping stations, ” said Bibhash Maity, the chief engineer in the civic water supply department. “When water meters are finally installed, we will have a fair idea of the extent of water usage.”
The mapping, which will cover the primary water mains and supply lines, will be done in phases. The first phase will cover the area from South Sinthee to Tollygunge.
French firm Seureca had carried out a pilot project using remote sensing technology in Ward 63 and at the Tallah pumping station in 2005.
“The pilot project helped us a lot in improving the water supply management. So, we have decided to replicate the model in the other 140 wards,” said mayor Bhattacharayya.
Work will start soon after the National Urban Renewal Mission authorities approve the scheme. Agencies that had executed similar projects will be invited to submit bids.
“The mapping will take some time as we don’t want to dig up roads. But we want the project to be over by 2015,” said a civic engineer.