If the Colorado River shut down tomorrow, there might be two, at most three, years of stored water in its massive reservoirs to keep Los Angeles, San Diego, Phoenix, Las Vegas, and dozens of other cities that depend on it alive. That margin for survival gets thinner with each passing year and with each rise in the average temperature. Imagine a day in the not so distant future when the water finally runs out in one of those cities -- a kind of slow-motion Katrina in reverse, a city not flooded but parched, baked, blistered, and abandoned. If the Colorado River system failed to deliver, the impact on the nation's agriculture and economy would be comparable to an asteroid strike.
Read all here. Water supply for the nation is another of those things made simpler if we make a real effort to limit population, even though the Chambers of Commerce want to see growth growth growth. Las Vegas, Phoenix, and LA are all built on the bogus proposition that somehow the water for the golf courses will appear.