Project to rejuvenate city’s groundwater brings livelihood, respect to traditional well-diggers

When machines replaced manual labour in construction and irrigation sectors in the last two decades, the Mannu Vaddars who traditionally dug wells went out of business.

The earth-diggers, a sub-sect of the Bhovi community, are getting gradual recognition as Bengaluru begins to grapple with the water crises and urban floods. The recharge wells they dug up in different city neighbourhoods are beginning to ensure water security, besides ensuring them much-needed income even amidst the raging pandemic.

Scattered largely along the peripheral areas of Anekal and Sarjapur, the community has been digging the recharge wells as part of the ‘Million Wells’ campaign initiated by Bengaluru-based Biome Environmental Solutions together with Friends of Lakes and other like-minded groups.

The community members have collectively dug about two lakh wells across Bengaluru that has replenished the city’s groundwater table.

The pandemic may have slowed down the pace of digging the wells, but the community has gone on steadily besides desilting the existing ones. Their work in Sarjapur Road, Bellandur Lake catchment area, Lalbagh and Cubbon Park has started to yield results.

“Besides recharging the groundwater table, we also wanted to ensure livelihood for this community members,” explained Vishwanath S, director of Biome Environmental Solutions. “More than 1,000 families live around Bengaluru. Their deep traditional knowledge and understanding of Bengaluru’s hydrogeology contributed to building the recharge wells.”

C Pedhanna, a member of the Mannu Vaddar community from Anekal, alone has more than 3,000 recharge wells to his credit in the last two years.

Friends of Lakes co-founder Ramprasad said the community knows the art of digging, something they have been doing for generations. “By involving all of them in the programme, our idea was to ensure at least Rs 2 lakh worth income to a family every year,” he said.

Well-digger Narayana said it takes one day for a five-member team to dig a single recharge well.

“The wells with a diameter of three to four metres goes to the depth of 12 to 15 feet, ideally,” he said, as he dug a well at JP Park. “It also depends on the soil we are digging. If we come across a rock, there will be delays.”

A typical recharge well with a depth of 15 to 20 feet will cost around Rs 30,000 to Rs 35,000. The earth diggers fill the recharge wells with pre-cast concrete rings and fill the surrounding with 40 mm stone jelly. The top of the well is sealed with a silt filter and a mesh to prevent anybody from falling in.

“It takes about just one hour for the earth to absorb 10,000 litres of water,” explained Jayaram another earth-digger.

Besides digging wells, the earth-diggers have also rejuvenated and desilted old open wells that could help percolate even more water underground.

Receiving 600 mm to 1,000 mm annual rainfall, Bengaluru can ideally recharge its groundwater table with 80 per cent of rainwater. “The city requires about 10 lakh recharge wells and our aim is to have one recharge well in every alternative property,” Vishwanath explained.

“Today, with over two lakh recharge wells, Bengaluru has the highest recharge wells among all the metropolitan cities in India. The overall rain percolation rate in Bengaluru ranges from three to eight per cent due to heavy concretisation of the surface. Our objective is to increase this to at least 50 to 60 per cent with these recharge wells,” he further explained.

One-stop solution

The recharge wells have also become a one-stop solution to prevent urban flooding. “During heavy rains, some parts of Cubbon Park used to be inundated and remain marshy for over a month.

"But now, all that stagnant water is absorbed into the earth by these wells and the land becomes normal in less than two to three days,” Ramprasad said.

“Similarly, in Peenya, a well was stopped at about 10 feet after we hit a rock. But the rock had cracks and it absorbed water within three hours of the well filling up,” he added.

Check out DH's latest videos