All this information is incoherent when viewed together, the only way to understand Washington's tunnels are in compartmented groups. I present it simply for the spectacle. If you see a few overlapping lines, you have found a tunnel used for multiple purposes. For example: the pedestrian tunnel (blue) beneath the Cannon House Office Building and the Capitol, which also conveys utilities. These multi-use tunnels are few and far between. Chances are more likely that the overlapping lines show seperate tunnels intersecting and overlapping in underground three dimensionality. 

Color codes:

  • Dark Blue: Drinking water

  • Reddish Brown: Sewage

  • Green: Transportation

  • Orange: Utilities

  • Light Blue: Pedestrians