As a double-check of GEOPAK Drainage inlet calcs I have modeled the same inlets in FlowMaster. Unfortunately, I am not getting the same results and I can't pin point why? I can provide some screen shots if necessary. Also, should I post this in the Road and Site Design forum as well, since it involves GEOPAK?
It's hard to say why you are seeing differences here. It would be best to submit your files to tech support so that the FlowMaster and GEOPAK support teams can investigate - appsnet.bentley.com/srmanager
Regards,
Mal