Lake activists in Bengaluru have begun diverting wastewater from reverse osmosis (RO) units to irrigate saplings around lakes, creating a local water-reuse model as shortages make it harder to maintain green spaces. The initiative is currently operational at Vengaiah Lake and has also been arranged at Ganga Shetty Lake.
At Vengaiah Lake, activists from KR Puram, Ramamurthy Nagar and surrounding areas have laid a pipeline from an RO unit located next to the lake to a plastic tank installed along the lake bund. The tank stores the wastewater, which is then used to water saplings planted around the lake.
The initiative was funded by an elected representative. Before the pipeline was installed, volunteers carried water from their homes in plastic cans and bottles. Some also paid private water suppliers to keep the saplings alive, adding recurring costs to an already volunteer-led maintenance effort.
“We were considering how to make the best use of the wastewater generated by the RO unit, and we are grateful to our elected representative for funding this initiative,” lake activist K N Guruprasad said. He added that the pipeline connects the RO unit to the storage tank at the lake bund, allowing the wastewater to be collected near the planting area.
Guruprasad said the approach could be replicated wherever conditions allow, through partnerships involving lake activists, philanthropists and elected representatives. He also pointed out that wastewater from several public and community RO units is discharged into roadside drains even when the units are located close to lakes and parks.
Lake activist Balaji Raghotham said he had arranged for wastewater from an RO unit to be diverted to Ganga Shetty Lake near the Tahsildar Office. The water is being used to irrigate saplings at that lake as well.
The initiative, however, has not resolved all the problems facing the lake plantations. Activists said stray cattle continue to enter lake premises and damage saplings, undermining the effort to establish and maintain green cover. They have asked authorities to repair damaged fencing and build a compound wall along the northern side of Vengaiah Lake.
“The authorities have yet to restore the fence to prevent stray cattle from entering the lake. With stray cattle entering the lake without any hurdles, we are finding it tough to protect saplings. I have already complained to the authorities,” activist Naveen AB said.
Guruprasad said volunteers had also installed plastic sheets at the entrance gates to keep stray dogs out and reduce littering inside the lake premises. A gap between the gates and the ground had previously allowed animals to enter. The next steps identified by activists are the restoration of fencing and construction of the proposed compound wall at Vengaiah Lake.
