Despite crores of rupees being spent on constructing and maintaining sewage treatment plants (STPs) near lakes across Bengaluru, many water bodies continue to suffer from severe sewage pollution due to poor coordination among civic agencies.

Lakes such as Halasuru, Sankey Tank, Vengaiah Lake, Seegehalli Lake, Gangashetty Lake near KR Puram and Vibhutipura Lake remain affected by untreated sewage entering through diversion channels and stormwater drains that are intended only for rainwater.

STPs fail to prevent sewage inflow

Several lakes have STPs nearby, but residents and environmental activists say the facilities are not being utilised effectively. At Vibhutipura Lake, an STP became operational last year, yet sewage continues to flow into the lake through a stormwater drain located on its western side.

Residents have repeatedly urged authorities to divert the sewage to the treatment plant situated barely 100 metres away, but no action has been taken.

“I thought the stormwater drain carrying sewage into the lake would be connected to the STP last summer, but the authorities concerned did nothing. What is the use of spending money on lake rejuvenation if sewage continues to flow into it?” asked local resident Subrat S.

Lake activist Shachi Pathak said she had written to authorities highlighting the issue and called for immediate diversion of sewage to the treatment plant.

East Bengaluru lakes among worst affected

Seegehalli Lake continues to receive sewage through a stormwater drain despite having access to treatment infrastructure nearby. Environmental activists claim that many lakes across east Bengaluru face similar problems.

“I have complained to the authorities several times to stop sewage from flowing into Seegehalli Lake. Most lakes in Bengaluru East are affected by the sewage menace. There is an STP near KR Puram and it is supposed to release treated water into Vengaiah Lake, but sewage continues to flow into the lake,” said lake activist Balaji Raghotham.

He added that many STPs appear to be falling short of the purpose for which they were established.

Agencies shift responsibility

Officials acknowledge the problem but point to jurisdictional issues.

Bengaluru East City Corporation Executive Engineer (Lakes) Bhoopradha said the maintenance of STPs falls under the Bengaluru Water Supply and Sewerage Board (BWSSB).

“I am aware of sewage flowing into Vibhutipura Lake. It is the responsibility of the stormwater drains department and BWSSB to ensure no sewage enters the lake. I will write to BWSSB regarding the issue,” she said.

A BWSSB Assistant Executive Engineer stated that the STP near Seegehalli was constructed by the former BBMP and said the authority would investigate issues related to Vibhutipura Lake. The official also confirmed that the STP near Vengaiah Lake is still under development.

Action ordered at Uttarahalli Lake

Meanwhile, the Bengaluru South City Corporation (BSCC) has initiated action to address pollution at Uttarahalli Lake.

BSCC Commissioner KN Ramesh inspected the lake on Monday after residents reported sewage and stormwater mixing before entering the water body, causing pollution and foul odour.

Residents requested repairs to a damaged retaining wall, diversion of sewage to the STP through pipelines, and the release of treated water outside the lake system.

During the inspection, the Commissioner directed officials to:

  • Remove weeds from the lake
  • Use bio-purification measures to control foul odour
  • Desilt stormwater drains
  • Remove blockages affecting water flow
  • Restart the suspended STP
  • Replace undersized sewage pipelines with larger ones
  • Prevent sewage from entering stormwater drains
  • Construct barriers to ensure only stormwater reaches the lake

Need for better coordination

The continued pollution of Bengaluru’s lakes highlights a persistent governance challenge. While substantial investments have been made in sewage treatment infrastructure, environmentalists argue that the lack of coordination between lake authorities, stormwater drain departments and BWSSB is undermining efforts to restore and protect the city’s water bodies.