| Product(s): | PondPack |
| Version(s): | CONNECT Edition, V8i |
| Area: | Modeling |
Problem
What is the best way to model a pond that has a spillway (weir) that operates separately from (in parallel with) another outlet structure such as a riser?
Solution
The approach to take depends on whether the spillway flow goes somewhere different than the riser outflow:
Note: The same concept applies to CivilStorm and SewerGEMS but in those products the composite outlet structure is specified in the pond outlet node element, whereas in PondPack it is specified in the pond outlet link.
If both discharge to the same downstream location or if you do not need to model the downstream hydraulics:
Add the weir in the same, single composite outlet structure as you have done, and set the "Downstream ID" field to "Tailwater" (to indicate that it is in parallel with the flow through the riser / other components)
If the spillway discharges to a different location than the riser and you need to model what happens downstream:
Add a second pond outlet node and pond outlet link connected to the same pond, and configure a separate composite outlet structure for it, with only the weir.
- If you do not need to route the outlet outflow to another location in the model, connect the pond outlet link to an outfall node. You can then graph the flow separately (from the weir vs. the riser). For PondPack, see the example model "Diverge.ppc" (in the Samples folder within the PondPack installation folder)
- If you need to route the outflow to another location such as a downstream channel or another downstream pond, connect the outlet link to either a junction (to transition to a conduit element to model a channel) or to an outfall whose "boundary condition" is set to "boundary" element (where you can specify a downstream pond to discharge to.)