Buffer dilution plan threatens Bengaluru water security

Bengaluru: In a move likely to have a major impact on Bengaluru’s water security and sustainability, the state Cabinet is going to take up the issue of reducing the buffer zone of Thippagondanahalli Reservoir’s (TGR) catchment area, with some government departments demanding that it be brought down to 30 metres from the current 2km.

“The government believes that the 2km buffer zone restricts development activities, especially the housing sector. What’s more, the Bengaluru urban development wing wants the buffer zone to be reduced to 30 metres. Their rationale is that when Ganga and Cauvery have a 30-metre buffer zone, why is Arkavathy special,” sources told DH. 

TGR is located at the confluence of Arkavathy and Kumudvathi rivers.

Ever since the buffer zone was notified in 2003, successive governments have been trying to reduce it and dilute the restrictions. In 2014, the high court stayed a government order withdrawing the notification. In 2019, the Urban Development Department reduced the buffer zone to 500 metres and lifted most of the restrictions. The court intervened again and asked the Forest Department to take the call.

Forest Minister Eshwar B Khandre said the matter will be discussed in the Cabinet. “The court has asked us to decide on the matter. We will place the same before the Cabinet, where a decision will be taken before filing the affidavit,” he said.

The government notified the buffer zone to protect the catchment area. The notification came after the drought conditions in 2002 and 2003, which had led to a spate of farmer suicides in the state, exposed Bengaluru’s vulnerability. 

Experts see TGR as a provider of two key services; preventing floods by absorbing runoff water in monsoon and providing 125 MLD drinking water to the city in the dry months.

Zone-I of the buffer encompassed the entire 1,453 sq km catchment area where mining and waste dumping were banned. Zone-II covered 2 km from the TGR boundary where all activities except agriculture were regulated. Zone-III included all areas falling within 1 km from the banks of Arkavathy and Kumudvathi rivers, where any activity other than agriculture required prior permission. Zone-IV was the 1 km area beyond the 2 km radius of the TGR where green industry activities were permitted.

A senior official told DH that TGR can provide safe drinking water directly to 12 lakh people and the catchment area plays a major role in recharging groundwater for another 20 lakh people.

He noted that despite the restrictions, thousands of violations have taken place and removing the same will only lead to a crisis.

“TGR is a special case because it directly supports the state capital. First, Bengaluru’s dependency on Cauvery water is not only costly but also unsustainable. Secondly, flooding in western parts of Bengaluru will lead to losses every year if the buffer zone is scrapped. Lastly, Rs 26,000 crore has been spent to bring 1.7 tmc water from Yettinahole to TGR and another Rs 320 crore for development of TGR itself. Keeping the buffer zone intact will help secure those investments,” the senior official added.

As per a report submitted to the High Court, there were 137 prohibited units and 146 unauthorised layouts in the buffer zone till 2014.

This has gone up multifold as per the latest report submitted by the Karnataka State Pollution Control Board in 2023. On the other hand, studies have shown the presence of banned pesticide DDT and heavy metals like mercury in the TGR waters.

The NGT had imposed a penalty of Rs 1.5 crore on industries polluting the TGR catchment area. R Anjaneya Reddy of the Shashwata Neeravari Horata Samiti noted that any decision to reduce the buffer zone will have a lasting impact on the city.

“The government is spending crores of rupees on Cauvery Aarati but refuses to see the damage that will be caused by its decision to reduce the buffer zone,” Reddy said. “Water crisis has become a recurring theme. Despite knowing that river rejuvenation is the best way to secure our future, the government seems set to undermine it,” Reddy added.

"TGR is a special case because it directly supports the state capital. First Bengaluru's dependency on Cauvery water is not only costly but also unsustainable. Secondly flooding in western parts of Bengaluru will lead to losses every year if the buffer zone is scrapped. Lastly Rs 26000 crore has been spent to bring 1.7 tmc water from Yettinahole to TGR and another Rs 320 crore for development of TGR itself. Keeping the buffer zone intact will help secure those investments," a senior official said.