How to divide water bill fairly

[Matt Kowske]

I have been told that sub-metering this building is not a possibility (without spending ALOT of money to redo the plumbing). Currently, we divide the water bill among all the units every 6 months and bill the tenants. This system was inherited from the previous owner and the tenants don't like it, for obvious reasons... some units have 1 person and some have 3 or 4 people using water. It is not fair and I agree, but how else can we do it? I have thought of charging based on the # of people in a unit, but that of course will encourage dishonesty in reporting the # of people in a unit and I'm not even sure that is a fair way to do it either.

Beyond creative ways of dividing up the water bill -- maybe I could figure out a way to sub-meter the units creatively? Apparently there is not a separate hot/cold line for each unit, but I assume it has to branch of somewhere. Are there small meters I could install in the units themselves? There are essentially 7 water lines in each apartment (as I see it, but I am no plumber): hot/cold for the kitchen sink, hot/cold for the bathroom sink, hot/cold for the shower and the toilet. Would it be insane to install a meter on each of those lines? I suppose that might end up being just as expensive... thinking out loud here.