Deep in the Mojave Desert sits Las Vegas where a torrent of water flows freely in massive fountains, pirate lagoons, wave machines, and casinos. Meanwhile, across the country in places that are not particularly dry or hot, communities, farmers, and factories are struggling to find water, and even running out altogether. From the Vegas Strip to faux snow in Atlanta, from our supersized bathrooms to mega-farms, from billion-dollar water deals to big...