Some time in the future you may be able to ante into a poker game in Las Vegas with water.

There was a movie, a B-grade film, but entertaining enough, "Ice Pirates". The protagonist, trying to obtain something on the black market, gets asked by the supplier, making the move usually applied to money, 'Do you have any water'.

I also liked that people didn't do much of the fighting. They left it to the robots. Who went at the other sides robots with an axe.

Who knows what Las Vegas might do if water got tight? Probably something grand and over-the-top. Perhaps a huge dome over the city to catch evaporated water. Maybe a huge water-from-air system run by a nuclear plant or a huge solar bank. They do have a lot of room for solar collectors.

Perhaps, poetic in its extraction of utility from discards, like Las Vegas itself blooming in the barren desert, It might sell itself for high-level nuclear waste storage and then use the waste heat created to run a desalination or water-from-air plant.