The worst megadrought in 1,200 years is plaguing the western United States. The Colorado River has dropped to record lows. And that has dire consequences because some 40 million people depend on that river for their water supply. CNN's Lucy Kafanov takes us to two Arizona communities that are at the epicenter of this crisis. The Rio Verde Foothills community outside of Scottsdale has had its water deliveries cut off as of January 1.