Is it a landlords obligation to send utility bills?
If you don't get billed you don't have a bill to pay. Don't worry about it. That or take your lease to the water department and change the name on the account. You aren't paying the water bill just because he tells you what he owes, are you? Go get this fixed and ask for back bills so you can budget for the coming year. If he was cheating you show him and get it fixed.