Recharge wells to power multi-city groundwater project

Seven years after ‘Million Wells for Bengaluru’ was set in motion, the programme — designed to raise the city’s groundwater table through recharge wells — is gaining traction with policymakers.

A pilot project on shallow aquifer management, initiated by the Union Ministry of Housing and Urban Affairs for 10 cities, under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT), has identified recharge wells as key to improving groundwater availability. Experts have cited the non-availability of space to allow the percolation of rainwater as a major hurdle to recharging Bengaluru’s groundwater table.

The Million Wells programme was launched by Biome Environmental Trust in 2015 to encourage citizens and communities to dig and maintain their own recharge wells. It also opened up employment for the traditional well-digger community, the mannu vaddars.

In Bengaluru, the Bruhat Bengaluru Mahanagara Palike (BBMP) will be the nodal agency for the project.

Biome Environmental Trust and Advanced Centre for Water Resources Development and Management (ACWADAM) will be technical partners in the project, which is led by the National Institute of Urban Affairs, a national think-tank on urban planning and development.

The pilot project also covers Chennai, Dhanbad, Gwalior, Hyderabad, Jaipur, Kolkata, Rajkot, Thane, and Pune.

Govt backing

Shubha Ramachandran, water sustainability consultant at Biome, said government-affiliated authorities and institutions backing the participatory approach to addressing groundwater concerns was an important step forward.

“Biome’s role in the Million Wells campaign has been that of a facilitator, helping individuals and resident groups build recharge wells at locations, including homes, office compounds, and parks. Since the start of the programme, the well-diggers have been finding more work and the most significant takeaway has been our engagement with the AMRUT project,” she told DH.

Rainwater that runs off the surface, when directed into recharge wells, percolates into the ground. Consistent recharging of the wells ensures replenishment of the shallow aquifer — weathered or porous rock capable of holding and releasing water, acting as a source for open wells — and the deep aquifer, from where borewells extract water.

An examination of Million Wells case studies showed that recharge wells helped residential communities shift from borewells to open wells. They have also been pitched as effective in urban flood control.

Biome estimates that more than 600 million litres per day (MLD) of groundwater is extracted in Bengaluru and only 90 to 240 MLD is recharged. A recharge well can recharge up to 10,000 litres of water on a rainy day, depending on the catchment’s size and rainfall.

A source in the BBMP said preparatory work on the project was on and a Detailed Project Report was being readied. The pilot will include inputs from the civic body’s lakes department, the source told DH.

An estimated two lakh recharge wells have been built in Bengaluru since the launch of the campaign, according to Biome. Vidyaranyapura, Koramangala, and Indiranagar are among the areas that have seen high activity.