Hydraflow Hydrographs Calculation Methods

[ad_crj_1234]

Does anyone know what assumptions the Hydraflow Hydrographs extension, makes about the connection between an Underground Chambers "pond" and the outlet structure?  I am trying to figure out why the maximum discharge elevation does not match the "maximum elevation" shown on the hydrograph report.  It would seem to me that these elevations should match; in fact they do if I am using a detention pond with the contours or manual storage method.  I assume the outlet structure is assumed to be sitting in the pond in the latter case; therefore, this would make sense.  But somehow it is assuming some amount of headloss between the underground chambers and the outlet?

Much appreciation to anyone who can enlighten me on this.

I've attached the troublesome file if it will help.  (You will have to remove the .doc; I had to add this to get it to upload.  .gpw was not a valid extension for some reason.)

[Timothy_Sean_Hulbert]

Greetings,

Thank you for your recent forum post.  My name is Sean and I am more than happy to help you with this issue. I understand you are using Hydraflow Hydrographs and the results are not what you would expect. I apologize for the inconvenience and I am more than happy to help. I evaluated the file you shared and I am not able to reproduce the results you are reporting. Could you please post a screen shot of what you are seeing, and also let us know what version of AutoCAD Civil 3D you are using?

I have subscribed to the thread though and will continue to monitor it should you need additional assistance. If you would like to communicate directly, you may do so at any time by sending me a private message in the forum.

[ad_crj_1234]

Thanks for your willingness to help.

I have attached three screenshots produced from the very same Hydraflow Hydrographs file attached above.

After further research, I can state the problem more clearly.  From the program, one can get a Hydrograph Report as shown in Screenshot2.  One can also view/print the El vs T graph as shown in Screenshot1.  Screenshot3 is a print of the Q vs T graph.

The Q vs T graph plot lists Maximum Elevation of 337.41 which matches that shown on the El vs T graph - Great!

However, the Hydrograph Report differs.  I thought the elevations for given times in the Hydrograph Report should match the graph.  After doing some manual calculations, it seems to me it is the El vs T graph that is wrong, and then the print of the Q vs T graph just picks up the wrong Maximum elevation to display on its printed page.

Also, I have found this problem presents itself whether a pond (contours/manual) or underground chambers are selected in Stage/Storage/Discharge Setup (Ponds Tab).

I believe this to be an error with the program, but would like to make sure I am not misunderstanding why these two different outputs should not match.

And, by the way, there is a "time shift" on the El vs T graph in that the proper ordinate does not match the proper abscissa according to the table (see Screenshot1).  This appears to be another error with the program.

Civil 3D 2017.