DDSWMM minimum major area

Is there a minimum area required for DDSWMM input files? I have a model
set up that returns the following error message:

*** ERROR *** Street Segment No. 723
No inflow into this segment from surface runoff or upstream
Check your input data....... EXECUTION IS TERMINATED

I have checked and rechecked the continuity of the input file and it is
correct. Street segment 723 has an area, albeit small, assigned as well
as 2 catch basins so in theory there should be surface runoff and inflow
to the minor system from this segment. If I remove this segment from
the input file I get the same error message for another segment and so
on. The segments that cause the errors all have small areas assigned (<
1Ha), so I think this may be the cause but I would like another opinion
before I start major modifications to the input file. I would
appreciate any comments or suggestions from anyone who has had this
problem or has a suggestion as to where I may have gone wrong.

Thanks,

George Blow, P.Eng.
george.blow@otttawa.ca