@RRPIKW 

Got it. I missed the Desktop part.  

Create an other current asset account (OCA) called Utilities Receivable.  Then create a service item called the same and under 'Account' in the item set-up, select the new Utilities Receivable OCA account.  When you receive the bill from the water co., enter a bill in QB with your portion as an expense and the neighbor's portion to the Utilities Receivable OCA account.  Do that for each month.  Then, when you need to bill your neighbor, create an invoice and use the newly-created Utilities Receivable service item on the invoice with the amount they owe you (should be the total in the Utilities Receivable OCA account).  That's it.