ICPR Boundary Outflow Question

[Jeff Raykos]

I'm working on an FDOT ICPR analysis for a commercial property We have to run a low starting tailwater elevation for max. flow and a high starting tailwater elevation for max. flood. For the low condition at the Boundary node I get a Max. Total Inflow of 12.45 CFS and a Max. Total Outflow of 0.0 CFS, which makes sense. However when I only change the starting tailwater elevation at the Boundary node to the top of the pipe instead of the invert, a change of 2.5', I then get a Max. Total Inflow of 12.23 CFS but a Max. Total Outflow of 28.40 CFS. Can anyone explain what the Total Outflow at the Boundary node represents and why this value jumps so high? Thanks.

 

[TerryScan]

How is the tailwater defined at the boundary node? Is the stage defined for the Time/Stage node for the full duration of the storm event or just the initial time?