The Brihanmumbai Municipal Corporation (BMC) has identified sewage line diversion as the long-term solution to combat the increasing spread of water hyacinth and other floating vegetation in Powai Lake. To this end, the BMC has issued two separate tenders—one for the diversion of sewage lines and another for the installation of an 8 million litres per day (MLD) sewage treatment plant (STP).
Additional Municipal Commissioner (Projects) Abhijit Bangar has instructed the relevant departments to issue the work orders by next week, with the project expected to be completed within 18 months.
As an immediate response, the BMC plans to deploy five machines and additional manpower to remove and transport the water hyacinth, a significant increase from the current two machines in operation. Over the past six months, approximately 25,000 metric tonnes of hyacinth have been cleared, but the growth continues to outpace removal efforts. Post-monsoon, six machines will be deployed to bolster the effort.
At present, 18 MLD of untreated sewage flows into Powai Lake daily, primarily due to rapid urbanisation around the lake and inadequate sewage management. This untreated inflow has accelerated the growth of water hyacinth, which covers the lake’s surface, degrading water quality and threatening biodiversity.
Bangar emphasised that the BMC has prioritised hyacinth removal and its disposal in landfills as a vital biodiversity conservation measure.
The initiative has been welcomed by environmental activists who have campaigned vigorously to save Powai Lake, launching online petitions and appealing to the Chief Minister and Municipal Commissioner for urgent action.
The BMC statement clarified that of the untreated sewage entering the lake, 8 MLD will be treated at the proposed STP on the site of the defunct Powai pumping station and then returned to the lake. Another 8 MLD will be diverted to the Bhandup STP via an existing sewer line, while the remaining 2 MLD will be rerouted to the Mithi River’s STP. These measures aim to halt the inflow of untreated sewage into Powai Lake.
Officials have also been directed to inspect key sites around the lake, including the Westin Hotel area, Ganesh Ghat, Pawarwadi Ghat, and IIT Bombay for further assessment.
Source: the Free Press Journal
