Bengaluru: 80% of borewells fail due to unscientific drilling, says hydrogeologist

Bengaluru: Eighty percent of the total borewells fail due to unscientific methods used to determine borewell digging points, according to hydrogeologist Devaraja Reddy NJ.

"There was a rule that borewells shouldn't be dug beyond 25 metres, but now they are being drilled as deep as 2,000 feet (approximately 600 metres)," he explained.

Reddy was speaking at Cauvery Bhavan on Friday during the first session of the Jalapatha symposium series. Jalapatha was organised by the Bengaluru Jalamandali Abhiyantarara Sangha to raise awareness about water conservation and management.

Reddy, who is based in Chitradurga, discussed techniques to reduce dependency on borewells and promote sustainable water management, such as rainwater harvesting and recharging existing borewells.

He emphasised the urgent need for rainwater harvesting and borewell recharge.

"India receives 1.12 lakh crore cubic metres of rainfall compared to a demand of around 71,000 crore cubic metres. However, not enough rainwater is being reused. Given Bengaluru's annual rainfall of over 900 mm, recharging borewells and rainwater harvesting can work wonders," he said. "I was responsible for digging 25,000 borewells, but now I am on a mission to replenish the water that was extracted."

Reddy noted that 80% of aquifers have been depleted, while the remaining 20% are in areas with minimal human activity.

He suggested that Karnataka consider desalination projects in Mangaluru, similar to Chennai’s desalination plant. "Around 25 per cent of North Chennai’s water supply comes from the desalination plant. We will spend about 22 paisa per litre for desalination," he said.