Bentley Product:: SewerGEMs V8i (Selectseries 5) Version 08.11.05.58 64 Bit
Project Notes: Analyzing Node DB-Detention Pond
Model A: Includes 8 detention systems to control runoff before it enters detention pond DB.
Model B:Includes 4 detention systems to control runoff before it enters detention pond DB.
The flowrate into node DB does not change with additional detention storage under 10-Year Storm ModelThe flowrate out of node DB increases with additional detention storage (model A) under 10-Year Storm Model.
Upstream detention nodes include orifice and weirs to control watershed runoff.
SewerGEMs - NEWR.zip
"Model A" is set to use a 1-year storm while "Model B" is set to use a 10-year storm. This means runoff will be higher from catchments in the Model B scenario.
I see that the "detention systems" that you added in the "Model A" are 4 additional ponds upstream, in series with the other ponds that ultimately discharge into the "DB" pond. It seems that this model distributes catchment runoff to these four additional ponds, to help prevent PO-6 from overflowing. If I change Model A to use the 10-year storm (to match Model B), I can observe this impact - PO-6 does not overflow and the overall volume of flow is the same (just attenuated from the ponds)
This does not necessarily decrease the peak flow into the "DB" pond though, because of a few factors:
Additionally, I noticed that you're using quite an old version, which will no longer be supported soon. See this article for more about our Support Policy and this article about upgrading. We have introduced many improvements to the numerical solver in newer versions, which may impact the results for your model.
Jesse DringoliTechnical Support Manager, OpenFlows ProductsBentley Communities Site AdministratorBentley Systems, Inc.
Answer Verified By: Suraj Kumar