There are limitations in PondPack regarding mixed use of ICPM and Level Pool (free outfall), though typically it happens in diversion situations (flow split). Can you provide an illustration showing how the ponds are connected and which ones are ICPM vs. Level Pool? (or provide a copy of the model files?)
See the following article for more information: Calculation failure or bad results with a mix of ICPM and Level Pool ponds
The solution typically involves using ICPM in all connected pond routes. For a level pool route connected to an outfall node set to free outfall, the outfall can be switched to Time-Elevation with an elevation-flow curve below the pond bottom (so as still to act as free outfall), and then you can change the upstream pond route to ICPM.
Jesse DringoliTechnical Support Manager, Haestad ProductsBentley Communities Site AdministratorBentley Systems, Inc.
Answer Verified By: Alex Palma
Thanks for the help here, and for the link. Attached below is an image of the pond configuration at this part of the drainage network. Sorry if I worded it wrong here - the outfall node itself for the pond is connected to another pond significantly farther downstream ("SWM 1B FB" in the image), so it is currently set to boundary element and not free outfall. In my composite outlet structure, "SWM 1C Outlet" is set to a tailwater type of "Free Outfall".
I'm hoping to avoid setting all downstream pond routes to ICPM - the model is already pretty slow due to size; but let me know if there's no avoiding it.
Hi Alex, you might need to make those ICPM to resolve this issue, but you might also be able to reverse the orientation to get around this. Would you be able to provide a copy of the model for review and so that I can see what ponds are upstream and downstream of the area shown in your screenshot?
Sharing Hydraulic Model Files on the OpenFlows Forum
Alright, sounds good. I've uploaded a copy of the model to the secure upload. I'd like to set "SWM 1C Forebay 1..." and "SWM 1C Forebay 2..." to interconnected ponds - I think the copy I uploaded has it set to free outfall to get it to run (sorry!).
The area previously shown in the image is at the top portion of the model.
Thanks for sending the model. Below is a screenshot showing the problem area - there are two level pool routes that have ICPM routes both upstream and downstream of them. If you change these two level pool routes to ICPM (be sure to pick the right pond for the TW range!) the model will run without error.
I have updated the related wiki article with this example situation.