1,000 recharge wells ‘may not make one summer’ in Bengaluru

Bengaluru: After a harsh summer last year and a rampant water crisis, is Bengaluru ready for another summer and an impending water shortage? This is a question haunting every Bengalurean.

While the Bangalore Water Supply and Sewerage Board (BWSSB) dug up nearly 1,000 recharge wells last summer, experts say that one year may not be enough to see improvement in groundwater levels.

In the last few years, 250 recharge wells have been dug up in Lalbagh, with about 74 in Cubbon Park alone.

Jagadeesha M, Joint Director of the Department of Horticulture, said that recharge wells in Lalbagh were constructed across three valleys — near the rock, glass house and near the Lalbagh lake. “Soil erosion has significantly improved after the construction of recharge wells. Borewell water has been improved before we imagined it would,” he said.

Vishwanath Srikantaiah, popularly known as the Rain Man of Bengaluru, said that in some areas, it might take as long as five years to see the difference in groundwater levels. “Locations are immaterial for recharge wells. Every house, every apartment, all gated communities can have them. But they should be designed to take rainwater from a clean catchment,” he said, adding that the function of a recharge well is to place excess rainwater into the aquifer.

Shashank Palur, Senior Hydrologist at Water, Environment, Land and Livelihoods (WELL) Labs, said that ideally, recharge wells are a long-term solution for groundwater recharge and digging them during the crisis may not see immediate results.

He said that an aquifer in earth’s crust is like a sponge — a mixture of soil and water, which determines the water-holding capacity of a region.

“When you dig a well, you excavate that area and water starts coming out. Recharge wells are usually dug up to 20 feet. If there’s a borewell nearby, which may go up to 900 feet, you will be tapping into a different source of water. While you may think that your borewell will be recharged, it may not always be the case,” he explained.

Further, Vishwanath said that recharge wells are one way everybody can participate in the solution space for Bengaluru's water challenge. “It is not the only solution,” he noted.

"If we build a million recharge wells and transfer one third or one half of Bengaluru’s rains to aquifers, we are better off than if we did not. It is not a silver bullet,” he said.

'One Billion Drops'

Last week, 12 rainwater percolation wells were built at Indira Gandhi Musical Fountain Park, each capable of conserving 1,28,100 litres of water annually.

The percolation wells were built by the United Way Bengaluru (UWBe) under its flagship programme, ‘One Billion Drops’.

This model helps communities understand the process, encouraging them to adopt similar rainwater harvesting solutions in their private spaces to conserve water and recharge borewells.

In the last few years 250 recharge wells have been dug up in Lalbagh. DH FILE PHOTO