If you had gone into central California in 1850 and said that twenty-odd million people would be living there by 2000....you would have been laughed out of the saloon. Without the irrigation....there’s no agricultural build-up in the late 1800s and a surge throughout the mid 1900s. Without the aqueducts...they never would have gone past two or three million local residents. You’ve got an entire region of the US...built on this notion of everlasting and permanent water delivered via the aqueducts. If you can’t ensure it....then there’s no future there.
And that’s one reason I don’t worry overly about “Aztlan”. Even if the Messicans ever managed to take over that part of California and connect it with Mexico, the water would shut off, and the whole place would dry up overnight. In their ignorance, the “reconquistas” have no idea what it takes to keep Los Angeles or the Imperial Valley alive.
Almost every city on this planet is located beside some body of water. There is a reason for that.