About setting flow direction
This topic applies to ArcGIS for Desktop Standard and ArcGIS for Desktop Advanced only.
![License License](rsrc/license.png)
While network features can be both created and edited in ArcGIS for Desktop Advanced and Standard, they are read-only in Basic.
You can use ArcMap or Geoprocessing to maintain flow direction in your geometric network. Flow direction can be defined by using either digitized direction or sources and sinks. Depending on which one you've chosen, the geometric network uses a combination of the digitized edge direction, network connectivity, the enabled or disabled state of network features, and the locations of sources and sinks to establish flow direction.
You must set flow direction whenever you do the following:
- Create a new geometric network.
- Add or remove features from the network.
- Reshape features so as to change the network connectivity.
- Connect or disconnect features.
- Add or remove sources or sinks.
- Enable or disable features.
- Reconcile a version.
Setting flow direction establishes the correct flow for the network based on the changes you have made.
To set flow direction using sources and sinks, your network must contain at least one junction feature class that you specified as containing sources and/or sinks. To set flow direction using digitized direction, your network must contain at least one edge feature class.