Here in Paraguay we can buy Californian almonds, they are sweet but expensive, so we buy them only when they are on sale. Off course they are flown in and we should avoid buying them at all, but that alone would not save any valley.

Thinking about the water shortage at some point a decision seems to be inevitable: Should California be a human habitat or an agriculture producer?

The quick check https://www.ycombinator.com/companies?query=sea%20water doesn't bring up any startup making sewwater fit for agriculture or even human consumption. I hope someone steps into that void and I won't mind if my almonds taste a little saltier.