Can missing elevations or elements be populated automatically between two known elevations or known elements?
This can be done using the Element Property Inferencing tool.
There are two general use cases for this tool
There is more information on using this tool that can be found in the 'See Also' section below and in the Help documentation that comes with the software.
Another option would be to take some constant and subtract that from the ground elevation if you have that. This can be done in the node flextable by adding the ground and invert elevations, copy/paste the ground elevation to the invert, then right click the invert field column header, choose global edit, then subtract the desired depth. For this case you may need to do some research on typical pipe laying practice.
1. The element property inferencing tool doesn't interpolate invert levels between drop manholes, i.e. when the start & stop invert levels are different. It would only work when the "Set invert to start/stop?" property is set to 'True'. This will be considered for a future version - reference enhancement #175199.
2. Currently there is no way to batch-run element property inferencing. If you have a large area of missing elevations with multiple branches and known ground elevations and you want to set constant slopes between known inverts at the upstream ends and downstream known inverts, you will need to run multiple passes. The new elevations from interpolation of one branch will determine the known stop invert elevation for another connecting branch.
How do I run the element property inferencing tool with a negative slop or an adverse slope?
Inferring ground elevation from surrounding elements