Bengaluru (DHNS): As the Bangalore Water Supply and Sewerage Board (BWSSB) looks for ways to reduce the Unaccounted for Water, which is almost half of the total water supplied to Bengaluru, a case study of success in the District Metered Area (DMA) of Vidyanagar in Kathriguppe has revealed that PVC pipelines are the main culprit in water leakage.

These pipelines were found vulnerable to the excess vehicular pressure and roots of roadside trees, thus leading to 24 per cent of total leakage of water at the distribution level.

In a presentation at the International Conference on Water Loss here on Tuesday, K S Renukumar, Assistant Executive Engineer, BWSSB, stressed the importance of changing the main pipes from PVC to Ductile Iron.

Consisting of about 2,000 household water connections, the Vidyanagar area in the BWSSB’s southwestern division achieved 14.53 per cent of Unaccounted for Water (UFW) from the initial 51.33 percent, where the water leakage was the major component. The target was achieved by replacing pipelines with introduction of additional valves as well as replacing old faulty water meters. With this, the board was able to save cost of Rs 68.45 lakh per year, he pointed out.

Of the reduced 36 per cent of UFW, the study found that about 0.37 per cent consisted of water metering errors. While 12 per cent was due to leakage at the meter points, around 24 per cent of leakage was found at the main pipes (PVC). “After converting the existing PVC pipes into DI pipes, we were able to reduce the UFW to 14.53 per cent,” Renukumar said, adding that there were no illegal water connections.

He said the use of PVC pipelines must be discouraged, especially in cities with heavy vehicular movement, and sought regaular monitoring of the UFW level and network maintenance, training of technical staff, participation of residents and periodical water audit of the DMA.

Taking the non-revenue water of entire Bengaluru, Renukumar said that the board would earn an additional revenue of Rs 570 crore a year, if the UFW was reduced to 16 per cent, thus saving about 377 million litres per day.

Prof Mohan Kumar, who chaired the discussion, spoke about the BWSSB’s ongoing project, which aims to improve the water distribution system, reduce unaccounted for water and leakage control in southern, western and central divisions of the City, consisting of about four lakh water connections.

Earlier, in a presentation titled ‘Impact of domestic water pricing on equity in water supply of Bengaluru City’, research scholar Vineeth V suggested the increase in domestic water tariff by simultaneously introducing cross subsidy for the lower income groups in order to make consumers understand the importance of water conservation.

Plugging

How BWWSB checked unaccounted for water (UFW) in Vidyanagar, Kathriguppe

Initial UFW: 51.33 pc
Final UFW: 14.53 pc
Reduced UFW: 36 pc
Metering error: 0.37 pc
Leakage at meter points: 12 pc
Leakage at main pipes:
24 pc.
Cost saved: Rs 68.45 lakh per year

Photo credit: DHNS