If people want to continue living in California long-term, nuclear-powered or less feasibly solar-powered desalinization plants are probably the only answer.

Desalinization uses enormous amounts of energy. I am not sure it can ever be worth it with solar or wind. Fossil fuels aren’t the answer, obviously.

Nuclear it is, then. As for the rest of the desert Southwest, better start building some pipelines I guess.

(The best solution is for people not to live there at all in great numbers, but yeah, humans don’t work like that.)