I also think human water consumption is dwarfed by agricultural and commercial water use.
Water can be scarce when people in certain geographical locations want more of something that was not there in the first place. So why are we developing those areas and then complaining about shortages? The shortage was in brains in the first place.
The World Bank and IMF are demanding of nations that participate in their system that they set up a system to charge for water, control the resource, and limit it's use. This is part of a program in order to maximize revenues from natural resources a country may have.
This water crap is just that. Water resources do not diminish globally unless aliens are coming here in space craft and stealing it.