Well, in some apartment complex the water is included in the rent. It assumes everyone uses roughly the same amount but of course some uses more then others. Often the water consumption decreases when the apartments are updated and have to pay for their own water.

One specific case that was in the media a couple of years ago. He lived in an apartment where the water was included and he had a tortoise. He tortoise liked warm water so the guy filled up his bathtub and had the tortoise in it, and in order to keep the water warm he let the warm water flow continuously. Of course this resulted in a huge water bill for the company which owned the apartments and they sued the guy. If I remember correctly the court ruled that he used such a vast amount that he should have known it was not included and he was forced to pay back all the water.