A terrace spread over 1,000 sq.ft. with rainwater harvesting (RWH) structure can help meet the water needs of two people for a year. Not only that, the structure will also offer surplus water.

Assuming that a family of two uses 80 litres a day, it will require around 29,000 litres a year. Whereas, the yield from the 1,000 sq.ft. terrace in a year will be around 36,000 litres, says K. Mylswami, project coordinator, Siruthuli. This is assuming that Coimbatore's average annual rainfall is 647 mm.