A couple of locals have been doing videos on the alarming drop in water levels at Lake Mead. It's nothing new. It's been going on for 20 years. But now, it is at crucial levels.

Here, they show how the water level has dropped, and how the reservoir is running dry:

https://www.youtube.com/watch?v=NCBG_aVkv4s

In this one (more recent), they show how the turbines at Hoover Dam, that generate electricity, are just about far enough out of the water that they won't be able to produce electricity anymore. That will shut down 1/3 of the electricity in Las Vegas:

https://www.youtube.com/watch?v=gND12rp0IDM&t=18m8s