Under-governed groundwater, lack of rejuvenation hurt city: Experts

The latest report of the Groundwater Directorate shows that despite the incessant rainfall last rainy season, the groundwater level in Bengaluru Urban and rural districts has gone down.

After a year of good rainfall, Bengaluru’s groundwater levels have seen an improvement in 2020 with four taluks — North, South, East and Anekal — in the city reporting an increase. A year later, the city is going back to square one.

Around 19 lakes have been encroached and most others are in a pitiable state that neither quenches the city’s thirst nor improves the groundwater table, experts say. (HT File)

The latest report of the Groundwater Directorate shows that despite the incessant rainfall last rainy season, the groundwater level in Bengaluru Urban and rural districts has gone down.

The report compared groundwater levels in December 2020 and December 2021. While the average groundwater level in Yelahanka taluk dipped by almost four meters when compared to December 2020, Anekal recorded a drop of two meters. In Hoskote and Nelamangala, which are on the outskirts of the city, the average groundwater level fell by four meters compared to December 2020.

Bengaluru urban, Bengaluru East and parts of Bengaluru North have registered an average rise in groundwater level of four meters above ground level, while Bangalore South has maintained the status quo.

City-based urban planning experts say the two reports show an opportunity than hopelessness. Authorities should take lessons from the report, they say, instead of the usual rant about how Bengaluru is running out of water.

The 2020 report said the copious rainfall in Bengaluru last year coupled with the lockdown-induced decline in demand by commercial establishments helped reverse a downward trend of dipping water levels.

The four talukas of Bengaluru have seen a marginal average rise in static water levels ranging from 0.30 metres to as high as 8.75 metres between 2016 and 2020, government data showed.

S Vishwanath, an urban planner and water conservation expert, said the increase in the water levels in some parts of the city was an indication that the water shortage was not irreversible. “If you look at the data, the areas where the groundwater levels are consistently dropping, are in the rural parts, or the outskirts of the city. This is where the water mafia has dug the borewells for their water supplies,” he said.

Vishwanath said while the government was pumping drinking water to Bengaluru, groundwater in the city is under-governed. “There is no structure, there is no management plan and there is a strategy for regulating groundwater exploitation. The drilling and extraction of groundwater in the city are done by private parties. And there are over 4 lakh borewells in Bengaluru. Not only is the government not monitoring the extraction, but even the recharging of groundwater is done by private agencies. The government has given up on it,” he added.

“The water mafia has sucked water dry and there is no groundwater because there is no recharge. The people are paying a heavy price and the water scarcity in the region is worrying,” said TV Ramachandra from the Centre for Ecological Sciences at the Indian Institute of Science.

He said over concretisation has led to the crisis but decision-makers are yet to acknowledge the dire situation the city faces.

Having lost the Vrishabhavathi River to overexploitation and lakes to encroachments, sewage inlets and bad maintenance, Bengaluru is heavily dependent on the inflow of Cauvery water from about 100 km away to quench its thirst.

Being Karnataka’s biggest revenue generator, successive governments have followed a predictable path of diverting Cauvery water into the city even if it deprives surrounding districts of its requirements.

With no river water in close proximity, the people in the hundreds of villages in erstwhile Bengaluru built lakes and tanks as a resource for irrigation and drinking.

Out of the remaining 210 lakes, around 19 lakes have been encroached and most others are in a pitiable state that neither quenches the city’s thirst nor improves the groundwater table due to over three to four decades of accumulated silt, experts said.

“An improvement in the groundwater level in the east zone can be due to the rejuvenation of Varthur and Bellandur lakes. This stresses the importance of maintaining our water bodies and desilting them,” said Dr Ramachandra, adding that there was a need for a comprehensive plan for rejuvenating water bodies in the city.

Former water resources secretary Capt Raja Rao said even though several proposals have been made to the government, there has been no serious implementation. “I had proposed the creation of recharging pits across the city, which would increase the groundwater levels. But there was no response. There is a definite lack of interest in the rejuvenation of process from the government,” said Rao.

Vishwanath said the government should also focus on streamlining the water supply in the city. Since there is inadequate water supply to some parts of the city, the overexploitation of groundwater was taking place. “In some parts of Bengaluru groundwater is available at few feet. This is because there is a proper water supply in these areas. If the government can get waterlines to all areas the dependence on water tankers will reduce. At present the city has enough water for another 20 years, the only problem is with the distribution,” he added.