Overwriting a network diagram rebuilds the network diagram content from network features and network objects currently selected in a geographic map.
You can overwrite a network diagram using the Overwrite commands 
in the Manage group on the Network Diagram tab on the ribbon or in the Diagram group on the Utility Network or Trace Network tabs. You can also use the Overwrite Diagram geoprocessing tool.
Using the tabs in ArcGIS Pro, there are two workflows to overwrite an existing diagram—either from the Utility Network or Trace Network tabs or from the Network Diagram tab in the ribbon. Those two workflows only apply to temporary diagrams. Overwriting a stored diagram is only possible using the Overwrite Diagram tool.
Requirements
The following prerequisites must be met before overwriting a diagram:
- The network topology must be enabled.
- Since this operation is transactional, edits must be saved before it is run.
- This operation applies to a network diagram layer that is from either a utility network or trace network in a file or mobile geodatabase, or a network diagram service. When working with a utility network or trace network in an enterprise geodatabase, the input network diagram layer must be from a service.
- There are network features or network objects selected in the network map you specified for the overwriting process.
- The network features and network objects selected in the specified network map and the network diagram share the same trace network or the same utility network branch version.
- There are no dirty areas on the input network features used to overwrite the diagram.
- There are no dirty areas on the container features related to the network objects used as input to overwrite the diagram.
- The All Layers diagram mode must be turned on for the diagram layer to which the operation applies so all layers are present in the Contents pane whether they contain diagram features or not. If it is turned off, click All Layers
in the Manage group of the Network Diagram tab.
Overwrite a network diagram
Note:
To limit the risk of unintentionally overwriting stored diagrams, you cannot overwrite a stored diagram using the commands on the ribbons. To overwrite a stored diagram, you must open the Geoprocessing pane and use the Overwrite Diagram tool.
There are two ways to overwrite temporary diagrams: either from the Utility Network or Trace Network tabs or the Network Diagram tab on the ribbon.
Select the network elements you want to use to overwrite a temporary diagram in the project
- Open the map view that references the utility network or trace network.
- Select the network features and network objects you want to use to overwrite your diagram content.
Use the network elements currently selected in the active map to overwrite a temporary network diagram
- Activate the map that references the network elements you selected and want to use to overwrite your temporary diagram.
- Click the network layer in the Contents pane.
- On the Utility Network or Trace Network tabs in the ribbon, click the drop-down arrow under the Overwrite button in the Diagram group, and click the temporary diagram you want to overwrite.
The temporary diagrams proposed in the drop-down list are those referenced in any open map and currently displayed with the All Layers mode turned on,
. If none of the open diagrams fit these conditions, the drop-down list displays No valid maps.
Overwrite the active temporary network diagram from the utility network or trace network elements selected in a map
- Activate the diagram map referencing the temporary network diagram you want to overwrite. Click the network diagram layer that corresponds to the diagram you are interested in.
- On the Network Diagram tab, click the drop-down arrow under the Overwrite button in the Modify group, and click the map containing the set of network elements you want to use to overwrite the active diagram.
The maps proposed in the drop-down list are those that are open and reference the same network as the one related to the active diagram.
Network diagram overwriting process
In all cases, the content of the specified diagram is rebuilt from the network features and network objects currently selected in the chosen network map. The process chains the diagram rules and automatic layouts that may be configured on the template on which the diagram is based.
The positions of any diagram features that may exist in the diagram before and after the overwrite are only kept for stored diagrams. They are not persisted for temporary diagrams.
For any diagram feature that didn't exist yet in a stored diagram or for all diagram features in a temporary diagram, the diagram features geometry will adhere to the following rules:
- Any diagram point junction representing a network point feature displays at the point feature geographic position.
- Any diagram point junction representing a network polygon feature is placed at the center of the feature boundary envelope.
- Any diagram point junction representing a network junction object is placed at best inside the diagram polygon container representing its spatial container with some or all other contents.
- Any diagram polygon container representing a container point feature displays as a rectangle around its contents which center is placed at the point feature geographic position.
- Any diagram polygon container representing a container polygon feature displays as a rectangle around its contents which center is placed at the center of the feature boundary envelope.
- Any diagram polygon container representing a container junction object displays as a rectangle around its contents and placed at best inside its own diagram polygon container.
- Any diagram edge representing a network edge object displays as a straight line between its from and to diagram junction.
- Any diagram edge representing a network line feature displays with the line feature geometry when the diagram template is configured to keep initial vertices on edges, otherwise it displays as a straight line between its from and to diagram junction.