Summary :: Usage :: Parameters :: Outputs :: Warnings :: Limitations :: Code sample


Identifies duplicate polyline geometries


This tool checks for duplicate polylines. Duplicate is the scenario when two polylines share the same FROM and TO nodes AND fully overlap each other. These errors are impossible to see, you can think of these as "stacked" lines which invalidate network topology. Such duplication is different to double digitised as those types of errors are either partial overlaps or weave on and off each other.

The tool filters the data down to candidate polylines and then checks for duplication. Large networks with many loops will generate large numbers of candidates that must be checked, so this tool has longer run times for large networks.  For a polyline to be considered a candidate to test for duplication it must share the same from- and to- node ID's with at least one other polyline.  This will of cause identify genuine simple loops but as they wont overlap they are not duplicated.

Any found to be duplicated have their polyline ID written to an error log table called tblDuplicate. If the table already exists then a new table name is created with a simple numeric suffix.

The tool optionally adds the error log table to the map (default) and if selected builds a standard relate between river network layer and error log table. You can use the relate to select and jump to the polyline to streamline your editing experience.




Data type

River Network

The river network. For best results the network should be within a File GeoDatabase

Feature Layer

Add Error Log Table to Map

If this is ticked (default) the error log table will be added to the map for your convenience if any errors were found.


Build a Relate for Error Log

If this tick box is checked then the error log table must be loaded into the map and RivEX builds a standard relate between the Error Log table and the river network layer. You can use the relate to help you jump to and review the error.



This tool creates a stand alone table named tblDuplicate, if any polylines are duplicated within the river network.  The table is created in the RivEX workspace folder and stored in the File GeoDatabase found in ..\RivEX_Workspace\ErrorLogs\fGDB_RivEXErrorLogs.gdb

Advice on the structure of the error log table and how it can be used is found within this section of the manual. Take note of the warning if you plan to construct a model using the error log output in subsequent processing.


Removing a duplicate is altering the topology of the network.  You must re-run your network through the Extract Network Topology and write to Workspace tool to rebuild and correctly attribute the node and polyline fields in your river network.  You should consider which duplicate to remove as one of them may have more attribution than the other and it's that one you should keep.

With the release of ArcGIS Pro 3.2.1 a switch control appears on parameters that accept tables\feature classes, do not interact with it! More advice here.


All polylines in the river network are tested, if a selection existed this is cleared prior to processing.

Code sample

A minimum code example showing how to call this tool in a python script. This can be run in console or your preferred IDE. If you right click on the tool in the RivEX toolbox and select properties you can view parameter order.

import arcpy

# Import RivEX toolbox

    # Input river Feature Class
    fc = r"C:\Temp\ORN\ORN.gdb\ORN"

    # Run RivEX quality control tool
    res = arcpy.scrQCDuplicatePolylines_RivEX(fc, False, False)

    # The rivers Feature Class, a derived output
    fcRivers = res.getOutput(0)
    # Get error table
    tblError = res.getOutput(1)

    # Check if error table exists
    if arcpy.Exists(tblError):
        # Count number of rows
        res = arcpy.GetCount_management(tblError)
        n = int(res.getOutput(0))
        if n > 0:
            print(str(n) + " error(s) were recorded")
        print("No error table created!")
except arcpy.ExecuteError:
    print("FAILED to quality control network")

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