Discharge-Storage Curve

[juany]

I have set up a routing diagram, entered all the data, run the program and obtained what appears to be realistic results. But when I check the nodes individually, the discharge-storage curve for a grass-swale <reach> shows the starting elevation same as the invert elevation, then it extrapolates...

A portion of the routing diagram consists of two sub-catchments routed to a grass swale then the swale flows into a detention pond

I've run the model and checked if any of the reaches, especially this one, was "flooded" but I don't get any errors of this sort. What could be causing this?

 

[psmart]

It sounds like everything is working properly.

For a reach, the rating curve will extend from the invert to the top of the defined channel. Extrapolation will occur only if the WSE exceeds the top of the channel, and a warning message will be generated. Since you have no warning, the model is not extrapolating, and is operating within the predefined rating curve.

BTW, there are two rating curves: Stage-Discharge and Stage-Storage. There is no Discharge-Storage curve.

If you have further questions please post the HydroCAD project file or send it to HydroCAD support.




Peter Smart
HydroCAD Software

http://www.hydrocad.net