Phoenix, Ariz., is a sprawling desert city with twice the population of Portland, Ore., and one-fifth its annual rainfall. The Valley of the Sun irrigates its golf courses with water channeled from the Salt, Verde and Colorado Rivers, while the City of Roses guzzles winter rains and stores the remainder in the reservoirs of the Bull Run Watershed.
What could these two cities possibly have in common? Simple. They both face seasonal water shortages if projections of population growth and climate change hold true.