Product(s):	WaterGEMS, WaterCAD, HAMMER, SewerGEMS, SewerCAD, StormCAD, CivilStorm, PondPack
Version(s):	CONNECT Edition, V8i
Area:	Layout and Data Input

Problem

When importing elements with ModelBuilder the following is displayed in the Statistics tab:

"### Pipe(s) could not be created due to missing topology."

The following is also displayed in the Message tab and the conduits or pipes are not created.

"Error: Unable to create Conduit <Conduit_Name> start and/or stop node could not be found. Ensure that either the start or stop fields have been mapped..."

Solution

This message could be occurring if the node elements are close to, but not exactly at the end of the pipe element being imported, if the source type contains geometry (ex: Shapefile). ModelBuilder does allow for a set tolerance. In the second step of the ModelBuilder process (Specify Spatial and Connectivity Options), find the item "Establish connectivity using spatial data" and place a checkmark in the box. The default tolerance is 1 foot, but can be made larger if needed. A larger tolerance might be needed if the GIS data was not created using the snapping option which ensures all the lines and points are linked together. You might also want to check to the "Create nodes if none found at endpoints" option if it is applicable to what you would like to do.

Note that if the node is outside of the tolerance specified, ModelBuilder will create a node at the end of the pipe element (if the option is selected to do so). If that occurs, you may need to either increase the tolerance or verify the spatial coordinates of the elements being imported. A good way of doing this without adding elements to a model is to load the shapefile as a background in a blank project. You can then see where the different element types are in relation to the other.

Non-spatial Sources

This issue can also occur when using a data source that does not contain geometry information (like a spreadsheet), if you did not import the node endpoints in the same ModelBuilder run and map the start and stop node fields for the pipe worksheet.

In order to create nodes at the pipe endpoints with a non-spatial data source, you will need to explicitly map the start and stop nodes for the pipe layer. For example for a spreadsheet you will need to have a worksheet which contains the end node information (unique label, X and Y coordinates and optionally elevation or other data) and import it at the same time as the pipe worksheet.

If you only have the start and stop coordinates for the pipe layer, you could look into converting it into ShapeFile format. When importing a Shapefile in ModelBuilder, it will be able to automatically create the end nodes based on the coordinates of the polyline endpoints as noted here.

ModelBuilder Error "### Pipe(s) could not be created due to missing topology."

Problem

Solution

Non-spatial Sources

See Also