... for California, Mexico, and various Indian tribes.
In exchange they'd get Colorado River water diverted to the Central Arizona Project the state is not currently entitled to in times of extreme drought. Assuming there's anything left below Hoover Dam...
https://en.wikipedia.org/wiki/Central_Arizona_Project
Arizona gets 36% of its water from the Colorado River.
Take it or leave it, nuclear power is the only non-fossil fuel energy source capable of supporting the lifestyles many affluent people are now accustomed to.
Since we still insist on using fossil fuels, especially natural gas here in the U.S.A., we'll just have to get accustomed to moving the populations of entire cities as the climate changes for the worse. We can do it with careful planning or not. Without a plan it will be chaos.
If anyone thinks the homeless problem is bad now, just imagine how bad it will be when people from places made uninhabitable by floods, drought, and high temperatures hit the road.