Here are the slides for my talk Upstream/Downstream: Discovering and Displaying Watershed Topology from !!Con 2016: Here's a link to the little video snippet I showed during the talk using Google Earth to show a 3D closeup view of a few of the watershed regions in the mountains where you can easily see how water flows from one into the next: The application itself is online here: My contact info is on the last slide in the PDF above, if you have any questions!