How do you bill tenant if You cant change the water bill from your name  If you rent your house out??

You can do this a few different ways. The most cost effective is setting up sub meters or implementing the RUBS system. There are companies that will set-up sub meters and handle the billing for you. It's $5/month per meter, or something like that, but the sub meter costs can be expensive upfront. I have one property with 3 units and I may eventually set-up sub meters but right now the bill is in my name and I simply divide it by the units each month and let the tenants know. They tack it onto their rent checks and I separate this cost out when doing my accounting.