Neighboring Ward 6 is the second fastest growing at 12.5%. Ward 6 includes Judiciary Square, Capitol Hill, and the Southwest Waterfront.
According to the Washington Post, that means redistricting is upon us -and Ward 2 has too many people in it. Wards 7 and 8 are the only ones declining, which do not border Ward 6, so some shuffling will have to take place--and it's sure to be a political battle.
Here is the Washington Post's chart of growth by ward:
And to help, a map of the wards:
Perhaps even more helpful is a list of neighborhoods in each ward, which is available from Wikipedia here.