MAX HGL vs Maximum Head

[Borys]

I am running 2 storm events (1:25 year storm and 1:100 year storm) for development.
For some reason for Jun-15 MAX HGL (Max water elevation) from Junctions Analysis summary and Profile Plot for 1:100 year storm is 31.29m and for 1:25 year storm is 31.32m.
At the same time in Time Series Plot for Jun-15 Maximum Head is 30.98m for 100 year storm and 30.8m for 1:25 year storm
By hand calculations Time Series Plot is correct.
At the same time for example Jun-14 MAX HGL and Maximum Head from Time Series Plot are the same.
What’s wrong?
Thanks.

[Chris Maeder]

Note that I reviewed your model, and some of the links are quite short. I believe that this is what is causing instabilities in your model.

Also, the reporting time step is a bit too large (5 minutes) and hence the model output is missing the peak discharge.

I have modified your model, setting the routing and reporting time step to 30 seconds. In addition, I set a lengthening time step of 5 seconds so that some of the very short links are artifically lengthened (without adversely affecting the model results). The model results appear to be much more stable and appear to be what you were looking for.

I have attached the updated model for you.