For a family that uses lots of water it can easily be $1,000/year. 

The sales paperwork said the property had a source of water that met the city drinking water quality standards.

Go to Redfin.com and select the zip code then go to "More Filters" and put in your criteria.

The pipes were stolen prior to contract resulting in water gushing inside and wet carpets etc.

Also, if you can't see them during the day, check in the dishwasher and around the the water heater with a flashlight. 

City Water and Sewer, separate utilities and Worcester property tax is reasonable, so PITI comes to just $1,871 for 100% financing which would mean $1,729 positive cash flow just for taking the thing.

I'd pay for water and sewage, which I estimated at $40 per unit per month - any advice to get a better gauge on what I could expect for that bill(s)?

Annual gross income $63,420.Cash flow $50,827Operating expenses: $12,593 as follows: Property Taxes  $4,123 Insurance   $2,201 Water/sewer   $1,184 Heating   $773 Hydro   $2,859 Lawn   $875 Maintenance   $578

I looked at an 1,100 sq ft house a few years ago where a thief stole the copper pipes and let the water run, flooding the house. 

There are a number of reasons for this, chief among them, the water and sewer systems are built for a certain population, so are the schools, roads etc.