Bellandur Lake to be desilted, but will it help?

Bellandur Lake, the city’s largest waterbody infamous for frothing and fire accidents, is set to be desilted in the coming weeks.

The Bangalore Development Authority (BDA) started draining the lake on Thursday. The water is being channelised to the downstream of Varthur Lake by opening up the sluice gates. The whole process will take a week, after which the lake will be desilted.

“We are lowering the water level on the instructions of the higher authorities,” a BDA engineer said on the condition of anonymity. A meeting scheduled for May 9 will decide when the desilting work will start and its extent (depth).

Lake activists and local residents are worried about shallow desilting.

“What we have learnt is that the lake will not be desilted to its original depth of 30 feet. It’s likely to be desilted only until 20 feet or even less,” said a lake activist who would not be named.

“If that happens, the very purpose of desilting will be defeated. The groundwater will not be recharged adequately.”

T V Ramachandra, a professor at the Centre for Ecological Sciences, Indian Institute of Science, had said that desilting would boost the lake’s storage capacity and remove contaminant sediments.

The blueprint for the rejuvenation of Bellandur and Varthur lakes suggests adopting state-of-the-art technology — wet dredging — to remove deposited sediments.

The BDA needs Rs 550 crore to desilt Bellandur Lake. Disposing of weeds and construction and demolition waste requires another Rs 36 crore while the construction of waste weirs and sluice gates will cost Rs 16.2 crore.