There is an interesting article on water in the FT (Wednesday, p9) on water. The top ten countries for freshwater, both surface water and groundwater, account for 60% of world's fresh water:
Brazil - 12.1%
Russia - 9.3%
USA - 7.8%
China - 6.8%
Canada - 6.2%
Colombia - 5.4%
Indonesia - 4.7%
Peru - 3.7%
India - 3.5%
Myanmar 2.8%
India and China have problems, particularly India, with only 1/2 as much water as China. But will Colombia, Peru and Myanmar become to water what the Middle East is to oil? By far the biggest use of fresh water by humans is for irrigation (2/3rds of total.) All efforts at conservation other than limiting irrigation will have marginal impacts. It would be better to address supply than demand, since irrigation is, as Martha Stewart would say, "a good thing."