To add an interesting fiction book: The Water Knife by Paolo Bacigalupi focuses on a hypothetical future where individual militias and municipalities/states in the South/South West fight and engage in near hidden warfare over access to the dwindling Colorado River. The wealthy are able to live in compounds where enormous amounts of water are recycled in a self contained system, while the less well off have to fend for themselves in what is a veritable super desert. It's quite dark, but a troubling possible future written in a clear hard sci-fi voice.