The Water Knife

Expanding upon the theme and setting of a short story written in 2006, "The Tamarisk Hunter," Paolo Bacigalupi takes us into the not-so-distant future where the scarcity of water has come home to the southwestern United States, with the consequent rise of the "haves" vs. the "have nots" and the violence, greed, depredations, treachery, and hopelessness that one would expect to follow.
Having lived in the Las Vegas metro area for four years and hearing the then-director of the SNWA (Southern Nevada Water Authority) say that they had no plan for managing growth/ development, this book felt frighteningly close.
In Bacigalupi's world, the states have become armed camps with their own militias and barbed-wire fences sealing the borders. Only the very wealthy can afford to live in the self-contained high rises that recycle their water, grow their own crops, and basically insulate their tenants from the harsh world of barren land, huge tenements built of salvaged materials, and communal water pumps provided by relief organizations--if you have the money. The price is visible on the pump meter, constantly fluctuating, as politics and power shift control for water futures from one entity to another. Arizona has less senior water rights than Las Vegas and California and the woman who controls the SNWA, Catherine Case, is ruthless is enforcing her rights, never hesitating to blow up pumping stations to strand thousands without water, or murder those who get in her way. One of her main enforcement tools is a paid hit man  she plucked from the slums, Angel Velasquez, known as a "Water Knife." Sent to Arizona to sort out some anomalies in Case's enforcement strategy, he comes across an idealistic Pulitzer winning journalist, Lucy Monroe, who has taken on the devastated southwest as her cause. She is now also pursuing the killers of a friend and it is in this quest that her path crosses Angel's. A third major character is desperate and determined teenager, Maria Villarosa, a refugee from Texas, who has lost her entire family and will do just about anything to get across the border from Arizona to California.
Well crafted setting, reasonably complex characters, and a compelling narrative all made this a good read and I will seek out more of Bacigalupi's work.
Bacigalupi has written several novels, including--in the climate sci-fi, or "cli-fi" genre--including the Hugo and Nebula awards winner, The Windup Girl (2009). He has authored books for YA's (e.g., Ship Breaker) as well as over a dozen acclaimed short stories. A list of his works and awards is available here.
Good reviews here from the LA Times, NPR, The Washington Post, and the Denver Post. There
 is an interview with the author, done in 2012 before he wrote this book, on the Publishers Weekly site.