Bengaluru: Sewage prevention at Puttenahalli Lake regains focus

Bengaluru: As the monsoon approaches, a committee led by the BWSSB chairman has directed officials to lay pipelines inside the buffer zone of the Yelahanka Puttenahalli Lake Bird Sanctuary “in order to revive the lake ecosystem and provide an all-inclusive solution for arresting the entry of sewage” into the lake — prompting the National Green Tribunal (NGT) to seek a plan of action.

The Bengaluru Water Supply and Sewerage Board (BWSSB) and the Bruhat Bengaluru Mahanagara Palike (BBMP) were pulled up by the southern bench of the NGT after millions of litres of sewage flowed into the lake during last year’s monsoon. The stormwater drain (SWD), built to carry floodwaters from layouts in Attur and other areas along the western and northern boundaries of the lake, had brought runoff mixed with sewage.

The Yelahanka Puttenahalli Lake Bird Conservation Trust opposed the departments’ move to lay hume pipes beneath the walking path on the lake boundary to divert sewage. The trust raised concerns about damage to the lake ecosystem and the long-term implications of such interventions.

Following the NGT’s order, a committee led by BWSSB Chairman Ram Prasath Manohar met with officials from various departments to address the issues raised — from the blockage of inlets and sewage inflow to the possibility of laying the pipeline outside the lake boundary.

At the meeting, members discussed the option of routing the sewage through the main sewage line and a “huge pit” located inside the nearby Ramanashree Enclave. However, residents opposed the idea, stating that the pit was meant to collect sewage from “only certain areas” and that a separate sewer line was necessary.

After deliberations, the chairman directed the BBMP to install a 1,600 mm pipeline for stormwater, while the BWSSB will build a 700 mm RCC pipe under the walking path. The committee decided that the work must be completed within 45 days.

A bench comprising Justice Pushpa Sathyanarayana and expert member Satyagopal Korlapati noted that 45 days may not be sufficient to complete the work. “However, due to the onset of the monsoon, it is for the authorities to take appropriate action to prevent sewage from mixing with stormwater drains, which would enter the lakes,” the bench said, directing the BWSSB chief engineer to appear at the next hearing slated for Friday.