Bengaluru: After decades of severe pollution caused by contaminated water flowing through the Vrishabhavathi river, Byramangala lake on the outskirts of Bengaluru is set for a major revival. The Karnataka government has approved a Rs 391-crore rejuvenation project aimed at restoring the long-polluted waterbody into a clean and reliable resource over the next three years.
Government sources said the minor irrigation department, which is the custodian of the lake, will carry out the restoration work jointly with the Bengaluru Water Supply and Sewerage Board (BWSSB). Minor irrigation minister N S Boseraju confirmed that the state cabinet has cleared the proposal, with most of the execution to be handled by BWSSB.
As part of the plan, BWSSB will set up a sewage treatment plant (STP) near the lake to ensure that no untreated sewage or wastewater from upstream areas enters the waterbody. “We will also undertake embankment strengthening and other rejuvenation works to restore the lake,” Boseraju said. He added that earlier attempts to divert sewage through a proposed canal in coordination with the forest, environment and ecology department were stalled due to a pending case before the Karnataka high court.
Senior BWSSB engineers said the revival of Byramangala lake has gained urgency as the government plans to develop Bidadi as a satellite township. Spread across nearly 1,000 acres, the lake once supported livelihoods in more than 20 surrounding villages, but untreated sewage from Bengaluru has over the years rendered it highly polluted.
BWSSB chairperson Ram Prasath Manohar said the proposed STP, estimated to cost around Rs 230 crore, will be operational within three years. “The plant will treat about 100 million litres per day of sewage. Tertiary treated, ultra-pure water will be released into the lake. This will be the third phase of the Vrishabhavathi valley project, and the plant’s capacity will be expanded later,” he said.
A senior engineer explained that the first two phases of the project at Nayandahalli and Mylasandra within Bengaluru are already supplying treated water to refill over 100 lakes in Ramanagara and Nelamangala taluks. “While the original plan was to supply 500 MLD, we are currently supplying 225 MLD. Pipeline upgrades are under way, and once completed, supply will be scaled up to 500 MLD,” the engineer said.
Boseraju said excess sewage beyond the capacity of the two existing STPs continues to flow downstream into Byramangala lake, sustaining pollution. “We will desilt the lake by removing accumulated pollutants before releasing clean water. The entire project is targeted for completion by 2028–29,” he added.
