Reach route in pipes drops flow rate to 10% of inflow

[annw2]

I am updating a Hydraflow routing I started back in 2003.

I had included a reach route of 700 LF of pipes.  I remember this working perfectly way back when.

The township Engineer looked at it and said the routing looked odd.  I hadn't touched in years.  I looked again and routing through the pipes dropped the flow rate to about 10% of the inflow rate for all the storms.  This should only have resulted in a delay of about a minute of travel time.

I use the 2009 version outside 3d as it is a royal pain to have to launch 3d, then Hydraflow when I want to update storm water design.  The data entry is also better then the version within 3d.

I gave up, added a minute to the Tc of the incoming hydrograph and combined the hydrograph uphill of the pipe reach for the hydrograph combination before the lower basin.

Is anyone aware of updates to the reach routing for storm pipe from 2003 to 2009?  Any other ideas of what is going on?