Cities used to be built where there were enough resources to sustain a population: Fresh water sources, arable land, what have you. Then we started just putting cities any old place where people wanted to live. Take, for example, Phoenix, a city that shouldn't have very many people in it, since it is in the middle of a desert. It certainly shouldn't have so many golf courses. But Phoenix has managed to, in fact, be a national leader in water saving. Despite having grown by nearly a million people, Phoenix is using less water than it did 10 years ago, part of a 20 percent reduction in water use since 1980. And, frankly, it sounds fairly simple; all our local governments should all be taking some notes. Read more here.