"Las Vegas, Phoenix, Los Angeles, even Atlanta, they're all unsustainable." What? Where did you get this information? I live it Atlanta and although we did have a drought a couple years ago, we've also had record rainfalls since then. Water issues in these cities can be rectified by increasing the price of water. As the price of water increases the excess use of water drops off (pools, yards, etc.) and the opportunity to innovate in water delivery and reclamation increases.