HydroCAD pipe flow

[ecamp]

I'm modeling a storm system to a pond and set up all aspects as flow segments in a subcatchment. I understand that for pipes this is open-channel flow modeling. If this is the case than why isn't it limiting my flow to the open-channel pipe capacity and spreading my flow peak? I can get it to do this if I route each subcatchment thru a reach but shouldn't the pipe flow segment have the same effect?

 

[TerryScan]

Flow segments in a subcatchment are components of Time of Concentration (Tc). Tc calculations are ONLY used to establish a time. There is no routing done for individual segments of Tc in typical SCS methodology.

One would typically verify capacity of storm drain systems with other software which accounts for inlet capture etc. Yet, one could model each element of the storm system in Hydrocad. One would need to break the subcatcment into smaller areas flowing to each element.

 

[ecamp]

I already have the areas broken up with respect to their structure and am uninterested in all the elements of the system. I know that the pipes are limiting the flow in some cases and the water is pooling. I just want the model to reflect the fact that the flow is limited to what the pipe system can handle.

 

[psmart]

If you want to model the pipe restrictions and resultant inlet ponding, you need to model each pipe as a pond with a culvert outlet. For details see

http://www.hydrocad.net/pipes.htm

and

http://www.hydrocad.net/sewers.htm

Peter Smart
HydroCAD Software

http://www.hydrocad.net