Yes, this is typical. We have an income line item for Water/Sewer bill-back (actually several: Water monthly ready-to-serve charge, Sewer RTS, Monthly water usage, Monthly sewer usage, admin fee, late fee).
This is a separate income item from Rent and separate from Fees.
The rates are set by the county on a yearly basis. So we charge 50xMeterRate(3/4") and we are only ourselves charged 3xMeterRate(2") because we have 3 meters that feed the 50 lots.
The RTS charges we get from the residents may more than offset our own water charges, but we have the costs when the sewer/water fails and that is baked into the cost of keeping the system RTS.