After fighting AutoCAD Civil 3D 2007 and Hydroflow Storm Sewers 2005 for several hours and a couple of e-mails to Intellisolve I figured out how to export a pipe network and wanted to try to help the next person.
The trick is to draw the pipe networks from upstream to downstream. This includes the branches, start at extreme upstream end and draw down stream to connect to the already drawn structure. Using 3D's draw up stream button does not seem to work and I can never remember to change the button.
It all seems so simple now...
I hope this will help the next person.
Bryan Parker
Elgin Survey & Engineering, Inc.