Good post on technological developments relating to desalination. Great observation that desalination (technology is the answer), wastewater reuse (we are moving toward an "effluent society") and rainwater harvesting (greater resiliency and sustainability starts with greater decentralization) will make up the three pillars of water resources management.
I also think that one axiom will be key this century - - who uses the least amount of water wins. Who utilizes the least amount of water between Fort Worth and Dallas per the same level of economic and livability output wins. Who uses the fewer amount of gallons of water per bottle of Pepsi or Coke wins. Who requires the least amount of water between Ford and Toyota per the same level of manufacturing output wins.
Water will start to flow to the bottom line this century just like energy efficiency and conservation.