[blurker]

It's surprisingly difficult to separate salt from water to the point that it's drinkable. That difficulty translates to it being very costly and that cost is so prohibitive that most places will choose another option. Like even building massive pipelines to transport water across 1000's of kilometers is probably going to be a better option. It's pretty much always going to be more economical to use the water that the earth is naturally desalinating for us.

[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.

[Obscurity4340]

Doesn't Israel (have the tech to) do it for like nothing or extremely nominal cost?

[josh_fyi]

Not nothing or nominal, but cheap enough that it is feasible, and about the same as other options. We also recycle 80% of the water, first in the world. The second-place country does 15%,

[kelnos]

Recycle to the point of making it potable again, or recycle for other uses, like agricultural? If the former, that is truly a wonderful achievement. (Even the latter is pretty great, though!)

[josh_fyi]

Even the recycled wastewater is potable, but it is use for agriculture to satisfy people's sensibilities.