Evansville IN huge rental issue

[Christopher Labonte]

Morning all!

I own a rental property in Evansville Indiana, and it preforms fairly well.  I do have a issue that's rearing its ugly head now.  One of the units lease is up March 31.  They called before the 1FEB to let us know they were giving they're 30 day notice.  Apparently they weren't aware of the lease (somehow...).  They also are about 200 dollars behind on they're water bill.  Unfortunately I only have 1 meter for this building (its a quad), but I do have individual in line meters going to the individual units.  I'm getting the feeling that im gonna end up getting stiffed.  

My property manager suggested when I bought the building that I just do a flat rate charge, and knowing what I know now I wish I had done it.  I was also contemplating shutting the water off to the unit, but I read a few BP posts and everyone says that's a terrible idea.  With all this in mind, does anyone have any suggestions on how I might go fixing this mess? Its either that or go the legal route, but with them moving in 2 weeks it looks like they're going to disappear.  All ideas are appreciated!