Nepal, Nov. 27 -- Water accounting and auditing, which are rarely done, should therefore be the starting point of any effective strategy for addressing water shortages and scarcity.

"Water is the driving force of all nature."

So said Leonardo da Vinci and the legendary genius was hardly the only person to notice its importance.

We use water for lots of reasons, from bathing and drinking to industrial needs, but above all to produce food. Agriculture accounts for 70 percent of all global withdrawals. Failure to use it wisely will lead to a sorry fate.

Today, one of every six people on the planet lives in areas facing severe water constraints. The vast majority of these are in Asia, even if Northern Africa, where one in five people conf...