Why can’t we pipe water to southwest US?

Question

We pipeline oil from Canada to Texas, why can’t we pipeline water from the Great lakes to the south?

Edit: thank you all who replied, I’ve gathered that it is technically possible, but would come with a huge amount of legal, environmental, and practical issues due to the amount of water that would actually be needed. It sounds like there are far more practical solutions available if the need became dire enough.

In: 45

Answer 1

Why would we need to?
Millions of gallons of water fall out of the sky every year- all we need to do is not let it run into the ocean.