Beside the fact Californian growers are wasteful water users, and thus can sell at "competitve" prices, after getting those governemnt subsidies via our tax dollars, there is another issue.
We should remember that Global Warming (or the natural tendency for the planet to heat up, if you don't believe in Global Warming) is causing a lot of freshwater to flow into the world's saltwater bodies and thus desalinating the oceans and seas which is endangering the entire planet's marine environment. We are now talking about desalinating even more of that water. Once these plants are built California growers will cmoe to rely on them even when there is no drought. Other places will follow suit, and eventually the ecosystem in the World's oceans and seas will collapse. NASA has already said that the collapse of the Western Antartic Ice Shelf cannot be stopped, and that's a lot of freshwater. It's a death spiral, and not sustainable. Better get focused on those Moon and Mars colonization projects, because we're going to kill this planet, sooner, rather than later. We're going to need options.