That might clarify things a bit; just follow the money...
So many people run off at the mouth without ever knowing the facts. Having lived in Las Vegas every drop is counted. The casino’s use less than 3% of the whole State of Nevada’s allotment and bring in 40,000,000+ visitors per year it is a great of water engineering,recycling and conservation not duplicated anywhere else in the world. Only Israel is more advanced with no where close to that many people per year.
Vegas and indeed all of Nevada gets the smallest share of Colorado River water they get at most 300,000 acre feet per year. California gets 7 million and dumps 5 million of that growing grass aka alfalfa in the deserts so Saudis can feed their cows no less. Vegas recycles every drop of water that hits a drain in the basin.
https://www.usbr.gov/lc/region/pao/pdfiles/crcompct.pdf
https://www.theguardian.com/us-news/2019/mar/25/california-water-drought-scarce-saudi-arabia
https://www.snwa.com/water-resources/current-water-supply/index.html