It’s an old D.C. adage that regardless of the differences between us, we’ll always have the weather, the Metro and the Redskins to gripe about. But if I had to add a fourth to that list of always-pertinent subjects, I’d probably suggest water. After all, it’s a topic that affects everyone in town, and plenty of residents probably have good questions about what’s going on with the water supply. The good news is that D.C. Water is embarking on a ward-by-ward tour answer such questions: the first installment of a city-wide town hall series in which General Manager George S. Hawkins and D.C. Water reps will share information about water quality, construction projects and customer service will take place in Ward 3 (inside the University of the District of Columbia’s Windows Lounge — that’s on the second floor of Building 38 at 4200 Connecticut Avenue NW) tonight at 6:30 p.m. — check out the entire schedule to see when Hawkins and company will be coming to your ward over the next couple of months.