I am trying to understand what calculations PondPack uses when you set culverts as a Downstream ID. I created a model that is utilizing culverts as the main outfall which will discharge directly upstream of a culvert crossing. I have the pond outfall set of culverts utilizing the culver crossing culverts as the downstream ID. Is this an acceptable way of modeling this scenario? I tried to use the interconnected pond methodology where a rating curve reflecting my tailwater condition in addition to my culvert crossing was input as the outfall structure of the tailwater pond but could never get a steady run.
Great! Thank you so much for your help.