Any significant change in how an economy works has physical consequences. You can see it and touch it, often smell it too. Go back to an area you used to live in or know well, and you can read the economic changes which have taken place, in the shops which have opened or closed, the look of the houses, the amount of traffic on the roads. Think of any major economic transition, such as the industrial revolution, and you can visualise the factories, railways, and urban areas that were built.
The Aakash Ganga (River from the Sky) initiative was developed to alleviate the perennial scarcity of drinking water, by harvesting domestic rainwater. The project channels rooftop rainwater from every house in a village, through gutters and pipes, to a network of multi-tier underground reservoirs.
