The pressure network modeling tools within C3D 2013 only model the physical properties of the pipes and does not do any hydraulic modeling at all. As Tim mentioned, you'll need to take it into a different program to do the analysis.
Autodesk did purchase several assets from Boss International including WaterNET but so far we haven't seen anything on that front. You can read about it HERE.
From that same aquisition we got Storm and Sanitary Analysis.