Pumping shut: No water supply today, tomorrow

The scheduled maintenance of three pumping stations, where Cauvery water is treated before being pumped to Bengaluru started on Saturday night.

The Karnataka Power Transmission Corporation Limited (KPTCL) is replacing 220 kV metering CT & PT (Current Transformer and Potential Transformer) for the refurbishment of the surge protection system. Meantime, the BWSSB has decided to fix the damage that may be caused due to the water hammer in the pumping stations at Torekadanahalli, Harohalli and Tataguni. This work can be done only by stopping the inflow. As a result, the water supply to the entire city will be disrupted on Sunday and Monday.

BWSSB officials at the pumping stations said the Cauvery water to Bengaluru would be pumped up to 450 m from the Torekadanahalli pumping station with at least 54 motor pumps being used in each station. “When the pumping of water is disrupted owing to power cuts, the water will automatically flow back to the pumping stations at high speed, damaging the motors, machinery and pumping accessories. So, this water hammer will be controlled by vacuum,” Ramesh S V, Additional Chief Engineer (Kaveri), BWSSB, explained to DH. “This acts like a shock observer, which is also called surge protection, and avoids further damage.”

The water hammer will be avoided by huge cylinders — vessels that are 10 m long and 3 m in diameter. This will be of different numbers at various places. Level sensors, compressors, censor shells, non-return valves, butterfly valves and other minor leakages will be addressed. This will make the surge protection system more efficient avoiding disruptions.