Hello Jesse,

Thank you very much for the prompt response. I have already design the two ponds, and they both work independently. Can I just connect them by interconnected pond routing? 

Jesse, I guess since the first pond is draining into the second one (Lower pond), the second pond will have to be resized to hold all the water from the first pond? will I have to add the Tc and area from the first pond into the second pond? Thanks!

[quote userid="1126072" url="~/products/hydraulics___hydrology/f/haestad-hydraulics-and-hydrology-forum/216622/designing-two-interconnected-pond-scs-method-in-pondpack/660367"]Jesse, I guess since the first pond is draining into the second one (Lower pond), the second pond will have to be resized to hold all the water from the first pond?[/quote]

After connecting the two ponds, you can compute the model and observe if there are any problems resulting from the connection, then make adjustments as needed, such as increasing the pond size.

[quote userid="1126072" url="~/products/hydraulics___hydrology/f/haestad-hydraulics-and-hydrology-forum/216622/designing-two-interconnected-pond-scs-method-in-pondpack/660367"]will I have to add the Tc and area from the first pond into the second pond?[/quote]

The Tc and area are part of the catchment polygon element, not the pond. Catchments describe the drainage area that discharges into a common point. A catchment has an "outflow element" designation to tell the program where the runoff enters into the system (for example a pond)

The catchments are independent from the pond, so if nothing about the drainage area is changing and you are simply connecting the two ponds together, you should not need to change anything with the catchment Tc/Area as they would continue to discharge to their respective outflow elements.

By having the outlet structure properly connected between the ponds, PondPack will have all the information if needs to route the flow from one pond to the other based on the EQTW tables that describe the relationship between elevation in pond 1, elevation and pond 2 and flow between them.

I would recommend reviewing the learning material to get an understanding of element connectivity and typical model workflows.

Yes you can connect them using the pond outlet node (linked to the first pond) > pond outlet link (configured with the outlet components you want and with the appropriate TW type like ICPM) > outfall (set as boundary element and linked to the other pond).

Hi Alex,

If you have not done so already, I recommend reviewing the learning material related to modeling interconnected ponds. You can find a directory of PondPack learning resources here. Of particular note is the Quick Start Lessons, which include a lesson on interconnected ponds (ICPM) - lesson #3. There should also be some helpful content in the formal training videos if your organization has access via a SELECT subscription.

There are also some example models included with PondPack that should help you - these can be found in the "Samples" folder inside the PondPack installation folder. The models named "ICPMPond" and "ICPM Channel" demonstrate the configuration of ICPM. 

The general layout for your case would be: Catchment (using SCS method) > Pond > pond outlet node > pond outlet link (configured as either ICPM for the TW type or level pool) > outfall (with boundary type set as boundary element and the element set as the downstream pond) > pond > pond outlet node > pond outlet link > Outfall (set as free outfall)

If it is possible for the downstream water level to rise above the bottom of the upstream pond, you would want to set the tailwater type of the first outlet link (between the ponds) to ICPM in order for the EQTW table to be generated and the downstream conditions to properly influence the outflow from the upstream pond (and potentially have reverse flow). Otherwise, set the tailwater type to level pool.

Jesse,

I have already designed my pond using the rational method; is there any way I can switch it to SCS method without having to start all over again? thanks