Hi,
I have a model in which a pond goes to an outlet structure to go directly to our storm system. However, we want to discard the water quality volume from that same pond to go to arbitrary outfall so it does not affect downstream of our system. I know what the volume that I need to discard is.
Therefore, I was wondering if it would be as simple as having two outlet structures with pipe attached to each of them, one for the water quality volume and one for the rest of the flow? For the water quality volume the pipe after the outlet structure would end in an outfall.
How would I make sure that only the amount of XXX of volume is taken to that pipe?
Thanks
I forgot to add that this is for Sewergems program. Thanks
Paola,
In general you will want to model the system as close as possible to the real system. What in the real system limits the outflow based on volume? (how is that accomplished?)
You can indeed model multiple outlets leaving the same pond. See the "Pond" section of this article: Modeling a flow split (diversion) in SewerGEMS or CivilStorm
With the pond outlet structure component in SewerGEMS, you can control outflow based on the available outlet types: orifice, weir, riser, vortex valve, user defined rating table. If you want to assume a specific, constant outflow that yields a certain volume, you could use the user defined rating table pond outlet type, assign it to a second pond outlet node attached to the pond, then connect that to a free outfall via a conduit.
Or, if this specific volume you're looking to "discard" is actually infiltration (water soaking into the ground around the pond), you can use one of the available seepage methods.
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Jesse. yes, the specific volume I am looking to "discard" is actually infiltration. What is one of the available seepage methods? I believe I have not used that before in this sewer gems program.
I can also try the user-defined rating table but I am also interested to know what you mean by the available seepage methods.
Thanks!
Jesse, would probably looking through the question and answer that I found on this thread (in bold below) help me walk through how I take into account the seepage infiltration for that pond?
Seepage (infiltration) is a property of the pond element. You will see the attribute called "Pond Seepage Method" in the "Infiltration/Inflow & Seepage" section of the pond properties. You can choose between a few different methods depending on which numerical solver you are using.
Prior to today, more information could be found in the Help topic "pond flow loss". I have now documented information about seepage in our Wiki here: Available Pond Seepage (infiltration) and evaporation methods per solver
If none of these methods are suitable for your situation, you can indeed use the approach of modeling the infiltration/seepage with a user defined rating table (varying flow as a function of headwater elevation) on a separate pond outlet structure.