Turbidity hinders water supply to parts of Bengaluru

Excess inflow into the Cauvery and Kabini rivers has made their water turbid, temporarily interrupting the filtration process at the Thorekadanahalli water treatment plant. This has, in turn, hindered the water supply to some parts of the city.

Kemparamaiah, chief engineer, Bangalore Water Supply and Sewage Board (BWSSB), said the magnitude of turbidity had reached 100 NTU (Nephelometric Turbidity Unit) after a gap of 10 to 15 years. "Normally, turbidity levels do not go beyond 30 NTU. But at present, they stand at 150 NTU," he added.

The reason for turbidity, according to Kemparamaiah, is the excess water released by dams that had carried away mud and natural vegetation in the river courses along with it.

"The presence of residual substances corrodes the sluice gates and these take a longer time to settle down in the filter. This has caused the delay in filtering the water that eventually interrupted the water supply," he said. "We are using the Pac powder to dissolve the residual substances and make them settle down in the filter quickly."

The chief engineer promised that the BWSSB would soon resume water supply to the city. "Only 10% of the water supply in Bengaluru has been affected. That is, the supply of only 100 MLD has been interrupted, while the remaining 1,300 MLD is going on. The magnitude of turbidity was so unexpected that we had to quickly respond to it. We have been working on it," he said.

The localities where water supply could be disrupted are Bommanahalli, Anjanapura, Marathahalli, Narayanapura, KR Puram, Hoodi, ITPL, GKVK, Nagawara, Jalahalli, Bahubali Nagar, MSR Nagar, Hegganahalli, Nagarabhavi, RR Nagar, Nandini Layout, Moodalapalya, Vijayanagar and Rajajinagar.