Bengaluru city never actually depended on lakes for their water source after 1896, says Rainwater Harvesting Club founder S Vishwanath. Only till 1895, when the city's population was just around 30,000, did people relied on these water bodies.
According to BWSSB, till 1896, unfiltered water was supplied to the city through the Kalyani system from a number of tanks such as Dharmambudhi, Sampangi, Ulsoor and Sankey. This was supplemented by local wells and stepped ponds.
Vishwanath rubbishes reports that Bengaluru is about to run out of water. "Cauvery water replaced the source of water from lakes, wells and step ponds. There is now a huge potential in harvesting rainwater in the city, which could easily act as a supplementary source," he adds.
The city, on an average, receives around 3,000 MLD (Million Litres Daily) of water. If at least half of this is conserved, then there can be a sustainable alternate source of water, says Vishwanath.
But compliance on RWH is extremely low. "People should start doing their own bit in saving water and harvesting rainwater for our alternate purpose. Though, BWSSB has made RWH compulsory, only about 70,000 houses have installed RWH structures."
Uttarahalli resident Rajesh Babu feels instead of drawing water from Cauvery and losing 40% of it during supply, the government should seriously look at harvesting floodwaters.