For this particular situation, that's a lot of money to spend just to serve already-well-off people willingly choosing to live in the desert in a drought.
More to the point, you've assuming the conclusion. If we could distill and pump water from the Pacific Ocean to Arizona at cost-effective rates then yes, it would be a significant technological innovation.
But knowing that it would be a significant technological innovation doesn't make it happen. We don't have many flying cars, even though the technology has been around for decades. Yet cheap flying cars would be a significant technological innovation, yes?
We already have the ability to transport Pacific water from the Carlsbad Desalination Plant in San Diego to Arizona, via the road system. If your argument has merit, then we should be seeing the existing price getting lower, right?
What isn't the price going down fast enough to meet the obvious demand?
"We don't have many flying cars..." because of reasons that are completely out of the scope of this discussion. The airspace has a different set of rules and "vehicle operator" requirements in comparison to...the ground. Considering that many have trouble operating ground vehicles in a safe manner, i doubt that we're ever going to have manually controlled "flying cars" being a viable transportation option. And no, they wouldn't be as significant as the shift from ground travel to AIR, as we already have air travel options.
I didn't say that there is "an obvious demand", in fact i said quite the opposite, that not many people are going to want to live in the desert. When you're talking about the costs, do you mean the costs of desalination, transportation or both?
The cost of desalination, the costs to build and maintain the tunnel/aqueduct system, the cost pumping water from sea level to 1,000 feet (elevation for Phoenix - likely more as the traversed part of the San Joaquin Valley is below sea level.)
To say nothing of the political and ecological costs - look at how well the Colorado River Compact has turned out, and the effect on the Colorado River Delta.
Water flows uphill towards money, certainly, but that's going to need a lot of money.
Speaking of the San Joaquin Valley, I would expect this water distribution system to irrigate California farmland first.
If you have an issue with my suggestion that perhaps more well-off communities could encourage the developments in the water technology, then i'd like to say that i don't mean that farmers needs should be ignored in favour of some "weirdos living in a desert".
> Are those projects unnecessary?
joshuaheard's hypothetical interstate water transport project? Yes, unnecessary.
There are other lower-cost solutions. It'll be cheaper to provide free Earthships / passive homes / etc. to everyone in the desert southwest and ban outdoor watering. It'll be cheaper to build a New Cleveland and relocate the entire population of AZ to Ohio.
If you want to live in the desert, stop pretending you live in the English countryside. Every well sucking up irreplaceable water is a temporary facade against reality, and that facade is now crumbling.
> to resolve the water supply issues in countries such as Australia for example
That's to provide for coastal cities, not to provide water to Alice Springs.
> perhaps more well-off communities could encourage the developments in the water technology
Don't you understand? They did. The story mentions wells drilled down nine hundred feet to find water, and transporting water from different watersheds. That's all based on improved methods for drilling, pumping, and transporting.
Before about 80 years ago, we didn't have pumps able to drain the Ogallala. Now parts of that aquifer are 300 feet lower. Improve the technology? Lower the level. Until it's bone dry. And then what?
Sometimes the only way to win is to play a different game.
"That's to provide for coastal cities..." which is closer to actual viable application, provided that those cities have a backbone to rely on in case the supply chain slows down for whatever reason.
"...Improve the technology? Lower the level. Until it's bone dry. And then what?" Yeah, sounds pointless, i understand your point now.
people want to live where it’s sunny and warm
The dispute is about scale: a couple of million retirees equal a lot of speculative housing value, but they don't justify a megaproject to deliver water to the middle of the desert. That would require population migration on a scale not seen in over a century in the US.