Most of America is now realizing water is not a commodity that is unlimited. Large parts of the country have been hit by record draughts and cities like Tampa have had to ration, or at least legislate water use.
Bloomberg put this excellent, and quite extencive story together that deals with the problems and possible solutions (if there are any) to such water shortages.
In most cases the shortages lead to tensions as water rights have been allocated a long time ago. In the US it is only now that such rights are contested (Atlanta is suing the surrounding areas for water) by various interested parties, but internationally such disputes will (or already have) also lead to international tensions.
Foreign Policy 101: resources, such as water, are called “global commons” as more than one country, party, or even just individuals, have “rights” to it. In most cases controlling access can be hard, if not impossible.
Read the article here.