water supply

[jesm]

I would not worry too mch, even with a 50 year, or longer horizon. We will always develop a solution to future water shortages, the main question is what will our water cost out in the future. Water is badly under priced at this point, too cheap for the benefit it gives, life itself, and to develop funds for the big, big projects that will be required as the "easy" water is lost.
We have the "silver bullet" already, social niceties just prevent its us: recycled wastewater. Yes, we can easily take all our wastewater and treat and disinfect so it is actually cleaner than the water we drink everyday. Problem solved but first we must get past "crap to tap" fears, but that will happen as water becomes properly valued.
Come to Mexico, the water be fine.