There are even places where water use is, really, not a big deal. My city pulls 100% of its water from a river. Sewage, after treatment, goes in the same river.

There are even places where water use is, really, not a big deal. My city pulls 100% of its water from a river. Sewage, after treatment, goes in the same river. Unless we suddenly grow by an order of magnitude, we are not putting any stress on the system.