Its not too hard to find a water key to shut off the water yourself at the street. I dont think it should be all that hard to make their life a little hellish to the point they will just find another house that can be fixed up and hopefully no civilian owns. If they did call the cops they would most likely say to them, theres nothing they can do, he owns the house and you dont have a lease or deed. Man Up. Your squatters are taking advantage of not only the law in your eyes but the fact that your scared to do something on their level. This is the wild wild Midwest, the laws here in Detroit are mere suggestions for many people. Get this fucknut out of YOUR house NOW, use your evil imagination without getting yourself in danger of course.

I hope you get your house back sooner than later Devman. Its very possible that it will be stripped of any copper. I suggest using flexible Pex tubing to replace it if the time comes [[knock on wood it does not), its much easier to install than sweating copper, wont burst when it gets below zero and has no value at the scrapyard and is cheaper than copper. I dont trust PVC for water supply and its almost as difficult to install as copper.