Plight of Phoenix: how long can the world’s 'least sustainable' city survive?

Set deep in the Valley of the Sun, the lush and sprawling 'megapolis' has a problem - the rivers

Jennifer Afshar and her husband, John, pushed their bikes across the grass and paused to savour the sunshine, while their two boys went to look at the duck pond. Other kids were playing soccer or doing tricks in the skate park, and families picnicked on blankets or fired up a barbecue across from the swimming pool.

"We moved here from Los Angeles, to get away from the rising cost of living and the traffic," said Jennifer. "When we saw this park, we thought they were punking us it was so good. There's low crime, the home owners association takes great care of the grass and trees - we like it."