HydroJunctions are points that are created from the endpoints of HydroEdge features plus additional strategic locations on the flow network. These include the location of Structures, Streams, QuadBasins, and MonitoringPoints projected to the flow network, as well as the centroids of waterbody polygons projected on the flow network. HydroJunctions are an important part of the Arc Hydro model in terms of creating the relationships among feature classes. It is through HydroJunctions that features in other feature classes are related to the network. HydroJunctions are created in the process of building the geodatabase, using a combination of manual and automated methods, as described in the methodology document. When new Structures, MonitoringPoints, QuadBasins, HydroEdges and Waterbodies are added to the database, new HydroJunctions need to be created. Date of last update: December 2013.