There's water in America but nearly all solutions to the problem has a downside. it's much too time consuming to try to explain to the lord's chosen few, and they resist learning anyway.I believe there is a huge aquifer under the desert in southeastern CA. Maybe they can tap it.
However, some of the very costly answers may have to be considered and then acted upon.
Sewer recycling. (partial solution)
Ocean desalification. (high energy cost)
Pipeline transportation of water long distances. (high cost)
Deep aquifiers. (earth quakes and cost)
Relocating agriculture or adapting to less use of water lost to evaporation. (??)
The god to the rescue. { a downside to only the non-believers)
There's going to be little interest as long as the lord's chosen few don't believe that climate change is making the areas suffering shortages, victims of climate change.