Anyone interested in the mind-bending history of moistening the West in general and California in particular just enough to be advertised as paradise may want to do themselves a favor and read "Cadillac Desert": http://www.amazon.com/Cadillac-Desert-American-Disappearing-.... (Not an affiliate link.)
I was just going to recommend this book myself. Before reading it, I had no idea how long some of these aqueducts are and how many dams had been built nationwide (and why) - now when I fly I can't help but trace water paths and look for dams. It's a great look in to how cities in the arid southwest can exist and just how close some could be to non-existence.
EDIT: This article does a decent job touching on the scale of the water projects in California. Cadillac Desert provides a decent look into that scale on a national level (though, admittedly, most of the mind blowing information revolves around California).
If you're going to take the time to recommend something, go ahead and put an affiliate link. It's pretty obvious if someone is here solely to spam. We're capitalists here, and aren't opposed to people making money.
I actually appreciate the non-affiliate link. I'm possibly as capitalist as the rest, but I appreciate the recognition of self interest by anyone who removes the affiliate bit from the URI.
EDIT: This article does a decent job touching on the scale of the water projects in California. Cadillac Desert provides a decent look into that scale on a national level (though, admittedly, most of the mind blowing information revolves around California).