I always liked George Carlin's explanation. Save the Planet. The Planet is not going anywhere, we are. There was also an answer to why we are here. The planet wanted plastic, and could not make it, so we were made to make plastic. Why are we here? Plastic.
In reality, there is only so much water in the area and the usage has outpaced the incoming supply. Vegas will no longer be an oasis in the desert, it will be a desert again. I have often wondered how much imported beer and bottled water adds to the downstream water table, has to be significant. Will global warming add water into the atmosphere and flood the mountains? Will la Nina add more water next cycle? Will the sun entering the next solar cycle add turbulence and increase evaporation of the ocean to replenish the snow packs? I dunno, but in 5 billion years or less, the big nuclear furnace 93 million miles away will grow into a red giant and eat the planet, so there is that.
Water rights are definitely smart, but yeah, eminent domain will take them if needed for a golf course that generates more tax revenues than your family farm.
Ok, let my adjust my tin hat and head back to the bunker.....
T