[slashdev]

Actually it's quite cheap, and Israel does it at scale, among other places.

It's just still much more expensive that just pumping free fresh water from rivers, lakes, and ground water. So you'd only do it if water were actually scarce.

I think this is why the scare-mongering over fresh water availability (agriculture excluded) is mostly just hot air. Fresh water is only scarce at ridiculously low prices. Raise the price and the market will solve the problem quickly. That matters for agriculture, but not for human consumption.

Even many dry regions that are far from the ocean, like the southwest US, only have water problems because most of it is used for agriculture at ridiculously low prices. Price it appropriately and that will end very quickly and there won't be any shortage.

[zbrozek]

Though the southwest is a great place to farm if you have the water to leverage the sun and the relative dearth of pests. Given the economic potential of a huge fraction of the country, I'd wager that getting water there will be worthwhile within my lifetime.

I'd love to see an aqueduct covered in solar panels roughly along I-40. Drain the too-wet southeast to irrigate the too-dry southwest.

[thaumasiotes]

> Though the southwest is a great place to farm if you have the water to leverage the sun and the relative dearth of pests. Given the economic potential of a huge fraction of the country, I'd wager that getting water there will be worthwhile within my lifetime.

The reason for the dearth of pests is that it's a desert. If you change that, the pests will arrive just like everything else does.

[zbrozek]

It's true, but that'll take quite a long time and the advantage is unlikely to evaporate completely even if it erodes. And there's probably no amount of water use that humans can realistically achieve in that same time period which will take away the sunlight.

[kelnos]

That's exactly the problem, though, no? If you keep raising the prices, then at some point desalination will be an attractive option.

Agree that the current system in the southwest/western US around agricultural water rights is just stupid, though. Agriculture uses water in some disgustingly inefficient and wasteful ways, because they're incentivized to do so.