Bengaluru sees healthy rise in groundwater level in 2 yrs

Groundwater levels in Bengaluru have increased considerably over the last two years.

Thanks to heavy rain, percolation wells and lake rejuvenation programmes, the average water table level across the city rose by two feet from 2020 to 2021, and by November 2022, another eight-foot increase was recorded, according to data by the Groundwater Directorate.

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Experts attributed the increase to multiple factors.

“It is a combination of multiple factors and we cannot single out a particular reason. Better implementation of projects to tap into rainwater and improve percolation into the ground has paid off. Rejuvenation of lakes in and around Bengaluru has also had a great impact,” said Ramachandraiah, Director, Groundwater Department.

Due to an initiative by NGOs, over 2,50,000 percolation wells have sprung up across the city over the last few years. They are now contributing to the rising groundwater levels.

“Just good rains are not enough. We need to ensure that there are enough recharge pits for the rainwater to percolate. Over the last two years, awareness has increased drastically and the number of such wells has also increased,” said Vishwanath S, a water conservation expert.

In Lalbagh, where the water level had dropped to 45 feet in 2019, it has now come up to as low as 15 feet. Close to 300 percolation wells have been dug in Lalbagh at strategic points to tap into the runoff.

“Now, during the rainy season, we get water at just five feet deep and this has had a positive influence on the health of perennial trees in the garden as well,” said M Jagadeesh, joint director of horticulture department, Lalbagh Botanical Gardens.

A representative from United Way of Bengaluru (UWBe), a non-profit organisation that has identified numerous parks across the city to dig percolation wells, said the impact can be felt after two full monsoon seasons.

“Each well can facilitate percolation of about 1,28,000 litres of water. It is critical that we identify open areas to ensure that the runoff water is captured. We have taken up a contour survey across the city to identify such strategic spots. In Lalbagh, the wells were dug up two years ago and we can see a visible increase in the water table levels,” said Sriram Ananthanarayanan, Director (Projects), UWBe.

The UWBe is aiming to dig 10,000 such wells by 2025.

It is, however, important to ensure that the wells are not polluted, pointed out Professor T V Ramachandra of the Centre for Ecological Sciences, Indian Institute of Science.

“Waste and sewage management in the city is not up to the mark. Many lakes are polluted with industrial effluents and sewage. If they enter these percolation wells, it will have a greater implication,” he explained.