Ben:
If your data is in Land Desktop or Civil3D, then StormNET can directly import this data using LandXML. Simply export your sewer network out from AutoCAD using the Export LandXML command. Then, in StormNET select File | Import | LandXML and StormNET will pull everything in. It will read your pipe inverts, pipe diameters, pipe lengths, manhole rim elevations, manhole sump elevations, subbasin areas, etc.
Please let me know if you have any difficulty with this.
Sincerely,
Chris Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com