archismcontracting, I'm not sure where you are seeing a reference to a "common water line" in that the MLS listings don't have such a category to click and identify. That could only come from the "Comments" section of a listing which with such limited verbage would be unlikely to post such a comment. Again as with your other question, it's best to call a Realtor and have them look up the Realtors MLS Listing and look for some Confidential Remarks or contact the Listing Agent and ask. Based on my 42 years of experience, I would guess that only means that as with most multi-unit townhomes that the water is paid for by the Developer/POA to make sure the grass is watered and they have a POA fee to pay to maintain the grass, so when you purchase the townhome you only own the improvements and not necessarily the land OR there is an easement. Not really a big deal or issue.