Culvert length

G'day,

I'm wanting to remind myself what the maximum reasonalble length is for the rectangular culvert routine is in MIKE 11?  I've a 130 metre lenth with 4 RCBC which previously have been modelled as closed sections. It may have been for stability i'm guessing, or the length which is where the question arises.

Cheers

Good day
      I think there is no limit for culvert length as long as Q-h relationship can be calculated.

Good luck