But of the 1,850 that once dotted the city, fewer than 450 remain today.
Many were destroyed to make room for high-rise towers, while canals were filled in with concrete — meaning heavy rainfall now sparks flooding and is not stored for the future.
Nearly half of Bengaluru depends on water sucked from intensive groundwater boreholes that often run dry in the summer heat, according to the city’s Water, Environment, Land and Livelihoods (WELL) Labs research centre.
Many residents already rely on expensive water trucked in from afar, and the problem is likely to get worse as climate change pushes global temperatures higher and alters weather patterns.
“We’re dependent on a precarious groundwater table, and that is going to get even more precarious as you have a more unreliable rainfall,” said WELL Labs chief Veena Srinivasan.
“We already don’t have enough water to drink,” she added, noting that “the water sources that we do have, we are polluting”.
Fixing lakes can ease the problem, though the city still needs a large-scale urban water management plan, she said.
Malligavad, trekking out to visit more than 180 ancient lakes, said he saw the “simple cost” they had taken to construct.
They did not use expensive materials but only “soil, water, botanicals (plants) and canals”, he said.
He persuaded his company to stump up around $120,000 to fund his first project, the restoration of the 14-hectare (36-acre) Kyalasanahalli lake.
Using excavators, Malligavad and his workers took around 45 days to clear the site back in 2017.
When the monsoon rains came months later, he went boating in the cool and clean waters.
The restoration process is simple, Malligavad said.
He first drains the remaining lake water and removes the silt and weeds.
Then he strengthens the dams, restores the surrounding canals and creates lagoons, before replanting the site with native trees and aquatic plants.
After that, he says: “Don’t put anything into it. Naturally, rain will come and naturally, an ecosystem will be built.”