30 minutes from Downtown(and that's with traffic). Big after work paddle scene. Many Olympic class paddlers.
Re. skiing. The advantage of DC is it's a capitol city. Airflights are plentiful (and cheap!) to wherever you want to be, whenever you want to be there. Anywhere in the country, or the world. Don't bother driving 10-12 hrs, through shitty traffic (unless your skipping work) for crappy skiing in New England when in the same amount of time, for about the same $, you could be in Salt Lake, Whistler, or Chamonix. Europe's cheap from DC, the flight times are good. Take advantage.