Is that a validated statistic? If so, how is the entire country not panicking about this? That seems like a really serious problem.
Ref: https://bangaloremirror.indiatimes.com/bangalore/civic/benga...
Most of the apartment complexes water supplies are provided by tankers. Local politicians have stake in these tanker services, so it is in their best interest to make sure local populace is dependent on the these tankers and not on government connections which is heavily backlogged.
Few societies, residents do get together invest their own money to get proper water harvesting, but that is far and few to even make a noticeable difference. Builders most of them flat out refuse to build robust water harvesting systems.
This is simply not as emotive an issue for elections as banning cow-slaughter or defending India from the evil Muslims.
Not to mention that Indian political discourse is basically a shit-show of politicians trading 3rd grade level insults with one another, a bit like monkeys flinging excrement at each other.
Some might be blinded by the space program and how technologically advanced India is/might be in this regard.
No time to look for solid water supply, especially if you're not living where water will become not available.