Subject:  Steady State Flow Analysis in InfoSWMM using a Ramp DWF


This can be easily created using a few steps in InfoSWMM. 


Step 1:  Using Scenario Explorer make a cloned Child Scenario and a cloned DWF Set which will be later modified.






Step 2:  Using DB Manager and the BlockEdit tool and increase the mean DWF by a factor of 10, 100 or 1000 to drown out all Wet Wells and cause the pumps to turn on and stay turned on during the simulation in the newly created DWF Set.





Step 3.  Run the batch manager and create two output files – Normal and Steady State for comparison.





Step 4.  You can now compare the two scenario’s using Output Manager and the Compare Graph tool.  The Ramped Model should have constant flows in both links and pumps.  It was not necessary to change any of the patterns.




Step 5.  The model is still  in balance – the excess DWF Inflow ends up as flooded flow and is listed as Internal Outflow.




You need to be a member of SWMM 5 or SWMM or EPASWMM - (not formally associated with EPA) to add comments!

Join SWMM 5 or SWMM or EPASWMM - (not formally associated with EPA)

Email me when people reply –


  • Subject:  Steady State Flow Analysis in InfoSWMM using an External Flow Time Series


    This can be easily created using a few steps in InfoSWMM.  The flow ramp is in the Routing Interface File.  The advantage is that you are able to have different ramps for the various nodes using this method.


    Step 1:  In Run Manager Set up the Process Models Options to use just the External Inflow and NOT the Dry Weather Flow




    Step 2.  Create the External Inflows File (see the help file for the format)


    SWMM5 Interface File


    300  - reporting time step in sec

    1    - number of constituents as listed below:


    2    - number of nodes as listed below:



    Node             Year Mon Day Hr  Min Sec FLOW     

    36               2002 01  01  00  00  00  0.000000 

    24               2002 01  01  00  00  00  0.000000 

    36               2002 01  01  01  00  00  1000.000000 

    24               2002 01  01  01  00  00  1000.000000 

    36               2002 01  02  01  00  00  1000.000000 

    24               2002 01  02  01  00  00  1000.000000   


    This file loads two manholes with a ramped inflow up to 1000 cfs to again drown out the wet wells and cause the pumps to have a steady flow.


    Step 3.  Use the Tab File command and use the created External Inflows File




    Step 4.  Run the simulation and see if the pump flows are constant.



This reply was deleted.