We have run into a complexing problem with our coupled model. We are coupling MIKE URBAN (MIKE 1D) with M21 (m21fm) in MIKE FLOOD. Our goal is to lower water surface elevations in the watershed. We have a storm water pump station at the downstream end to help empty the collection system and lower the surface water even further. We find that the pump makes things worse in the watershed (deeper) rather than better (lower).
We have tried discharging out of the system by leaving the To Node for the pump blank and by discharging to a large storage tank away from the surface. Neither seem to help. The bigger the pump the worse the condition. It is exactly opposite of what we would expect. Anyone run into this situation before?