"Globally, current withdrawals [of water] of about 4,500 cubic km exceed the availability of about 4,200 cubic km. By 2030, the demand is expected to increase to about 6,900 cubic km, with a slight drop in availability to 4,100 cubic km. Thus, by 2030, a global deficit of 40 per cent is forecast. For India, the annual demand is expected to increase to almost 1,500 cubic km, against a projected availability of 744 cubic km; a deficit of 50 per cent.
"India’s average annual precipitation is about 1,170 mm, and the land area is 3.28 million sq. km. Thus, the volume of annual precipitation input is 3,840 cubic km. The projected availability of 744 cubic km constitutes about 19 per cent of this amount. In comparison, California, known for its spectacular hydraulic-engineering structures, diverts about 18 per cent of its annual rainfall."
--- [Comment: If California has managed to save only 18% of rainfall, how likely is India in saving close to 40%?] - T S NarasimhanArticle
