Borewells dry as these two Bengaluru lakes were denied water for 4 years

Both waterbodies, spread across a total of 1,200 acres, stopped receiving treated sewage and rainwater after since the Bangalore Development Authority took up lake rejuvenation work four years ago.

Bengaluru: The delay in rejuvenation of Bengaluru’s two major lakes may have contributed to the drying up of borewells in and around Bellandur and Varthur region, experts and residents believe. 

Both waterbodies, spread across a total of 1,200 acres, stopped receiving treated sewage and rainwater after since the Bangalore Development Authority (BDA) took up lake rejuvenation work four years ago. 

As part of the rejuvenation, the BDA has diverted the water inflow for desilting the lakes but incomplete work has severely affected the groundwater table. 

When these lakes were filled with water, many residents living in the vicinity said they could at least depend on private tankers even when their borewells dried up. Some residents said their tubewells worked around the year until the BDA started desilting lakes, which should have been completed in a year. 

“A major part of the groundwater crisis in Bengaluru is the draining of Bellandur and Varthur lakes for desilting,” Vishwanath Srikantaiah, a water conservation expert, said. “Bellandur Lake alone, spread across 330 hectares, can recharge 66 million litres per day. That is equivalent to 5,500 tankers (12,000 litres). Varthur could recharge 36 million litres per day. A total of 102 million litres per day recharge missed out has caused the groundwater collapse,” he said. 

As an emergency measure, he said, the BDA should fill these lakes with tertiary treated wastewater. “These two lakes, biggest in Bengaluru, have an influence zone to fill aquifers not less than 10 km,” he said. 

He gave an example of Doddabommasandra Lake in the north of the city. “BEL has set up a 10 MLD secondary wastewater treatment plant. The BBMP pays the electricity bill of Rs 10 lakhs a month. About 300 million litres becomes available to fill lakes and recharge aquifers,” he said. 

Amaresh, president of Green Glen Layout Resident Welfare Association, said borewells of residents living close to Iblur Lake were getting water but the ones near Bellandur Lake had dried up.

“After Iblur Lake was rejuvenated, it has water to fill the aquifers but the work in Bellandur Lake has been going on for years,” he said.

'Need one more year’

Even though the water crisis is severe the BDA is in no hurry to complete the work. An engineer in charge of the rejuvenation project said it would take another year to completely fully Bellandur Lake. “Until then we will not be able to allow water into the lake” he said adding Varthur Lake is in the advanced stage of completion and hoped to allow the flow of water by December-end.  Former MLA Arvind Limbavali blamed the BDA for destroying a project conceptualised by the National Green Tribunal (NGT) committee. “Had these lakes been full the borewells would not have gone dry to this extent. Of the 110 villages added to the city limits 31 fall in my constituency and all of them are facing severe water shortage” he said. “I am struggling to supply water even through tankers as the suppliers themselves are seeing their borewells going dry.”  Shobha Bhat a resident of the Jnana Bharathi ward blamed the unscientific rejuvenation of the lake for the water problem. “The BBMP focused on the beautification of waterbodies in the RR Nagar constituency. As the water holding capacity of these lakes has narrowed down many borewells in our area have gone dry” she said.