Probably a lot of readers of /r/water have read Cadillac Desert.
I own a copy of, and have made two false starts reading, The King Of California as recommend by the anonymous author of the blog On The Public Record.
I highly recommend A Great Aridness, a worthy heir to Cadillac Desert.
Also on my to-read list is Rising Tide. I would like to find a book that does for the Great Lakes what Marc Reisner did for water in the American West with his book Cadillac Desert.
A few things I've read this year that have little to do with water:
EDIT: Oh, and Flash Boys: A Wall Street Revolt