Another problem is that millions of gallons of water falls as rain and snow in areas where no one lives.

I live in the West of Ireland and it rains a lot but the east of the country can experience shortages as there are too many people using too much water. This has been caused basically by not charging for it and through underinvestment in water infrastructure.

In rural areas most people pay for there water as they have to join a local scheme to pipe water to there house yet in urban areas they can get it for free and so they waste a lot of it.