Set Flow Direction (Trace Network)


Sets the flow direction of features in a trace network.


  • The network topology must be enabled.

  • Flow direction can only be set for line features that participate in a trace network.

  • Flow direction can be specified at the feature level with digitized direction, against digitized direction, or as indeterminate. When a selection of features exists on the map, the flow direction will be set for only those features.

    Learn more about how to set flow direction


SetFlowDirection(input_trace_network, in_edges, flow_direction)
ParameterExplanationData Type

The trace network that contains the edges class on which the flow direction will be set.

Trace Network; Trace Network Layer

The polyline features that participate in the input trace network.

Feature Layer

Specifies the flow direction of the edges.

  • WITH_DIGITIZED_DIRECTIONFlow direction will be along the digitized direction of the edges.
  • AGAINST_DIGITIZED_DIRECTIONFlow direction will be against the digitized direction of the edges.
  • INDETERMINATEFlow direction will be indeterminate.

Derived Output

NameExplanationData Type

The updated trace network.

Trace Network

Code sample

SetFlowDirection example (Python window)

Set the flow direction with digitized direction for the HydroLines edge class.

import arcpy
                          "HydroLines", "WITH_DIGITIZED_DIRECTION")


This tool does not use any geoprocessing environments.

Licensing information

  • Basic: No
  • Standard: Yes
  • Advanced: Yes

Related topics