It won't happen due to the staggering energy requirements to lift water up and over the Rocky Mountains. For that level of energy expenditure, it would make more sense to desalinate water closer to those places.

What might make more sense is growing more warm climate fruits and vegetables in the Great Lakes with the abundant water supplies as the climate there gets warmer, and exporting those elsewhere.

This is already happening in portions of the southern UK which are now growing champagne grapes as the traditional locations in France are getting progressively drier.

The Great Lakes Compact forbids that. As an agreement between states it went through US Congress, so theoretically an act of Congress could repeal or modify it. However this seems unlikely to me due to the Midwest's outsized political influence and how protective locals are of the lakes.

The Great Lakes Compact has a giant loophole you could drive a train full of water right through.

You can export water out of the watershed in containers no larger than 5.7 gallons (~21.5 liters)

Build a short loop of rail, half in the watershed and half out of it. Drive a train in a circle continuously. When you are inside the watershed, fill up the 5.7 gallon containers (just make it a continuous waterfall that you drive through or something). When you are outside the watershed, dump them into a reservoir/pumping facility. There's nothing anybody could do about it.

> There's nothing anybody could do about it.

All the states with GL watershed agreed to the compact not-so-long ago. In a case of such egregious rule-skirting, couldn't they just agree to close the loophole?

Read up on the Nestle bottled water situation in Michigan. Nothing is being done, or proposed to be done.

They could shoot you.

There are international treaties with Canada that are supposed to forbid that. But yeah, that remains a worry.

The treaty mentioned:

https://www.gsgp.org/media/nvzkrpyv/great_lakes-st_lawrence_...

The US imposes treaties, it doesn't follow them, and Canada is a national security threat, so any treaty requirements can be ignored for national security purposes

Yes, hence why I said "remains a worry". Though the treaty is signed between various states on the US side, too, and some US states have interests that compete with others on these matters that might be the one thing that saves us here in Ontario & Quebec.