> But desalination isn't that kind of technology — it's the destructive kind.
But is it really? You're effectively doing what occurs in nature. Clearing land and building a distribution infrastructure is destructive, but certainly no more than what is already going to happen regardless of whether or not desalinization is used. Pumping from salt water aquifers might qualify as well.
> My question was genuine.
It was, but your comment seemed dismissive of alternatives. I don't think that objectively adds anything to the conversation. I apologize if that wasn't your intent.
I can see a solar desalinization system in place in areas where much of the water you encounter underground is brine or otherwise non-potable, and it's particularly useful in areas where other methods of collection won't work. Yes, it has the potential drawback of kicking the can farther down the road in terms of potentially extracting water faster than it's replaced. But that said, in much of the west, the topography lends itself well to draining much of the run off into large basins and water ingress likely far outpaces whatever could be pumped out of the ground. Perhaps a hybrid (rainfall collection + solar desalinization) would be ideal.
I think you're focusing exclusively on the advertised "seawater greenhouse" and may not be aware of the benefits such a design would have in areas where there certainly is plentiful salt water, just not from a sea.