Shekar Raghavan and Ram Krishnan

Dr Sekhar Raghavan, a professor of physics was one of the first to realise the imperative of saving rain water for Chennai. Chennai has over 1200mm of rain fall per year but routinely lacks even drinking water. What Chennai needed to do was to save the water that fell as rain. Its Ganga was in the skies. Raghavan was one of the first to preach RWH. He installed a RWH system in his house and began to organise his neighbourhood to do likewise.

In faraway USA, Raghavan's activism made the Chennai-born Ram Krishnan recall how his mother would wake up at 3 am to collect water from a capricious tap. Ram and Raghavan connected and formed the Akash Ganga Trust.
The idea was to raise awareness about the effectiveness of RWH as a solution to community water needs. They went on to build the Rain Centre in Chennai where the simplicity of the RWH idea was showcased. Ram raised Rs. 400,000 and the Centre for Science and Environment [CSE] chipped in with support and inputs. It's a small residence converted into a resource centre.
Within a year of that date, a majority of buildings all over Tamil Nadu—and Chennai in particular—had RWH systems in place. Water levels in wells across Chennai rose. Brackish water tended to get sweeter. There was less flooding in the roads. A lot of the money earlier spent on tanker loads of water, stayed in wallets.