runoff generated, no pond inflow

[clemk]

Attached is a simple SSA file of a single basin going to an underground stone trench.  The trench then has a series of outlets.  Anyway... the subbasin "Sub-01" generates 6.28 cfs of runoff.  However, the results indicate a "peak inflow" into storage node "Stor-01" of 0.00 cfs.

Any tips on why the system is not passing my 6.28 cfs into the pond?

Thanks!

Clem

[Matt.Anderson · Accepted solution]

Clem -

This one had me stumped for a bit, but it is easily solved.   The analysis is reported to run for a total time of a day from start to finish. (It probably should run a little longer with the use of a 24 hour Huff Distribution) The calculations for hydraulic routing are set for 15 seconds.

The issue is the reporting time step - it's set for 1 day.  That is, the final report is set to report the value at the start and end of the day only, and their are no intermediate saved data.  You want you reporting time step to be equal to or a multiple of the routing time step and the solution file will contain reported data.

[clemk]

Matt,

I would be curious also why / how the “peak inflow” into Stor-01 is greater than the peak flow of “Sub-01”?  Or maybe a better question: what is the difference between the “maximum lateral inflow” and the “peak inflow”?

  *****************

  Node Flow Summary

  *****************

  ------------------------------------------------------------------------------------

  Node                Element     Maximum     Peak      Time of   Maximum Time of Peak

  ID                     Type     Lateral   Inflow  Peak Inflow  Flooding     Flooding

                                   Inflow            Occurrence  Overflow   Occurrence

                                      cfs      cfs  days  hh:mm       cfs  days  hh:mm

  ------------------------------------------------------------------------------------

  Jun-01               JUNCTION      0.00     4.07     0  01:34      0.00

  Jun-02               JUNCTION      0.00     3.71     0  01:56      0.00

  Out-01               OUTFALL       0.00     2.12     0  01:56      0.00

  Stor-01              STORAGE       6.27     7.74     0  01:26      0.00

[clemk]

Attached is the "working" file.

[Matt.Anderson]

Clem -

I would adjust your time steps to achieve a better balance for your System.

  *****************
  Node Flow Summary
  *****************
  
  ------------------------------------------------------------------------------------
  Node                Element     Maximum     Peak      Time of   Maximum Time of Peak
  ID                     Type     Lateral   Inflow  Peak Inflow  Flooding     Flooding
                                   Inflow            Occurrence  Overflow   Occurrence
                                      cfs      cfs  days  hh:mm       cfs  days  hh:mm
  ------------------------------------------------------------------------------------
  Jun-01               JUNCTION      0.00     3.07     0  01:47      0.00
  Jun-02               JUNCTION      0.00     3.07     0  01:47      0.00
  Out-01               OUTFALL       0.00     3.07     0  01:48      0.00
  Stor-01              STORAGE       6.27     6.27     0  01:30      0.00

Lateral Inflow is the sum of runoff plus any external inflows. (For your model, there is no external flows and the runoff from Sub-01 is all that should occur for Stor-01.)

Peak Inflow is Lateral plus upstream flow.

For your model, they should match.  In the model you submitted, there is some stability and continuity errors that will resolve with smaller time steps.