One of my architecture instructors was (still is) a top guy in the sustainable/green building trade, usually $500k+ homes but he advises on all levels of construction. He said housing developers in California have told him the water shortage is even worse than people realize, and the current water restrictions are nowhere near enough. There will have to be major lifestyle and agriculture changes out there. I forget the state, not California, but a 10-15 year old housing development had to basically be abandoned because they couldn't supply enough water to sustain it.