text: My guess is that when it goes underground (near n967653354), it is simply directed to a sewer or runoff main. At that point it isn't really possible to map without infrastructure plans. 
  
  The NHD survey was 2008, and Esri Clarity from 2010 shows the development just starting, so it was likely just a stream that appears after a rain, coming down from the hill. It probably gets very little water and if not for the tunnel entrance I wouldn't map it at all.