Start Invert not populating for ~90% of pipes in dataset

Question

I have a dataset with nearly 3000 pipes in it, that have the start and stop inverts identified. When I am doing the initial setup through modelbuilder, roughly 90% of the start inverts are populating as 0.000. Stop inverts appear to be populating without any issue. I've gone through the modelbuilder process several times and keep getting the same result. 
 Attached is a zipfile with the project files and the dataset. UPELEV attribute is start invert, DOWNELEV attribute is stop invert. 
 Bentley Support.zip

Yashodhan Joshi · Answer

Hello Jamie, 
 I checked the shapefiles you shared for manholes and conduits. Here are my observations; 
 For the manholes shapefile you have the attributes for both Elevation (Ground) being mapped with "RIMELEV" and Elevation (Inver) being mapped with "UPELEV_MIN". However, there are about 148 manholes where the "UPELEV_MIN" value is absent and another 24 manholes where the value is "0". 
 For the conduit shapefile you have the upstream and downstream elevation values and not the actual manhole labels to be mapped. You require these attributes to be mapped in the Start and Stop field in the conduit shapefile. 
 Jamie Purdy said: With that in mind (that I didn't include the manhole information) I ran the initial model setup without the manhole dataset, and all of the inverts populated just fine. So this issue only occurred when performing the initial model setup with both the manholes, and conduit datasets. Sorry for not including that information originally, that was an oversight on my part. 
 In this case when you are bringing in the data using both the manhole and conduit shapefiles you can get the manhole data without any issues but the conduit shapefile does not have the start and stop node attributes hence you have to choose "establish connectivity using spatial data" to map to the closest manholes. 
 When you are running the ModelBuilder with only the conduit shapefile the upstream and downstream manholes are automatically created you would have to check the option of "Create nodes if none found at pipe endpoint" to make sure that your upstream and downstream manholes are generated. However, these wont be as per your GIS-ID's for the manholes and they also won't have any elevation data by themselves. 
 I tested two runs of your model in which first I tried simply importing both shapefiles without using the option for spatial join and the results were satisfactory. I was seeing the start invert elevations for my conduits. When the inverts were set to "Set Invert to Start?" they have taken the manhole invert values and if you globally uncheck this or set it to "False" the invert levels specified in the conduit shapefile have also been imported. The same is the case when the spatial join option is used. 
 When I checked the model it seems that most of the manholes which have a zero invert level do not have any conduit associated with them so these values are not reflected in the conduit invert values.