My mother-in-law has had her water cut off and refuses to pay the bill. What do we do?

My Mother in law is 89 years old and has alienated everyone, except of course strangers. She has no will, given no one power of attorney. She doesn't even want any family on her heppa form at the dr. office. She has refused to pay her water bill and now it has been turned off and she still refuses to pay it. No one in the family can make her understand that she has to pay her bills and she refuses to let anyone know her business. Do we need to call the health department? What do we do?