Once a source of drinking water, Bengaluru river now filled with froth, stench

A river that once provided drinking water for villages outside Bengaluru city is now often mistaken for a sewage drain. The water is now unfit for drinking and the unchecked flow of industrial pollutants and domestic sewage and tons of plastic dumped in the river has made it difficult for the people to approach the river because of the froth and stench.

The 57-km-long Vrishabhavathi river used to be a picnic spot in the late 1960s. Thanks to the pollution, the only river that originates from Bengaluru city now has an alternative name – the Kengeri Mori (Gutter of Kengeri).

Experts say the decay of the river has an impact on Bengaluru’s ecosystem that goes beyond the froth and stench it generates; it could affect the quality of groundwater in the areas that it passes through. Farmers in the outskirts of the city use this water for the cultivation of vegetables that end up on the dining tables of the city’s residents.

The degradation of the river began around 50 years ago when industrial areas began cropping up along the catchment areas of the river – in Peenya, Yeshwanthpura, Kumbalagou and so on. Over the years, industrial effluents polluted the river but in recent times, the big pollutant has been domestic sewage.

“In terms of volume, domestic sewage contributes to the bulk of the pollution. Most households in Bengaluru don’t connect their sewage to the lines provided by the civic authorities. These (sewage) lines are meant to take the domestic affluents to a treatment centre. But the people connect their sewage to stormwater drains, which eventually take it to the river,” said Dr Sharachchandra Lele, a distinguished fellow at the Ashoka Trust for Research in Ecology and the Environment.

Lele, however, added that industrial pollutants too pose a serious problem because most of the effluents let into the river are not biodegradable.

The pollution has changed the nature of the river as well. In the early days, Vrishabhavathi was a seasonal river, flowing only during the monsoons.

“Now it has been a perennial river, just that the main water body in the river is Bangalore’s sewage. At least for 6-9 months, what flows in the river is primarily sewage and it is around 500-600 million litres per day,” Lele added.

Has there been any plan to revive this river? Experts say no. “It has to be a sustained, systemic effort if we have to revive the river and it could take a long time. The sewage entering the river should be diverted to sewage treatment plants. Industrial effluents will have to be collected and treated at effluent treatment plans and groundwater tables will have to be brought up so that groundwater flows into the river. This will take 5-7 years. Sadly, no such long-term plans have been proposed by anyone,” S Vishwanath, a city-based water conservationist, said.

A senior official at the Bangalore Water Supply and Sewerage Board (BWSSB), who didn’t want to be named, pinned the blame on Bengaluru residents.

“We have sewage treatment plans in the city, but the problem is that we don’t get sewage from the households to treat it. In most areas in Bengaluru, the sewage is directly dumped into the stormwater drains, which are meant to collect excessive rainwater. We are taking action, but how much we do?” said the official. The Karnataka State Pollution Control Board (KSPCB) said it has booked more than 500 apartment complexes in the city for letting sewage into the stormwater drains.

An official said that the board had recommended to the BWSSB and Bangalore Electricity Supply Company to cut power and water supply to these apartments.

While the blame game over the condition of the river continues, the effluents let into the river are slowly making their way back to the city.

“The baby corn, other vegetables, fodder and the milk from the cattle from the villages downstream come into the city. If the quality of water the cattle drink and the water that is used for cultivation is bad it could certainly affect the city-dwellers directly,” Lele added.