As a general rule for necessities, if you want it to be cheap enough for the poor to be able to comfortably use what they need it has to be cheap enough for the

As a general rule for necessities, if you want it to be cheap enough for the poor to be able to comfortably use what they need it has to be cheap enough for the rich to waste it. For water specifically, Private use is a drop in the bucket compared to commercial and agricultural use.