Bill,

If you use the the "6" th option on the J1 line of SWMM 4.4g to SWMM 4.4h as in this example:

J1 6

you can input a stage or tide boundary condition at multiple points in Extran. The tide or stage data is referenced as the 5th scratch file or NSCRAT(5) in the JCL of SWMM. Here is an example of how the data may look in the ASCII NSCRAT(5) file:

2 1
'outlet1' 'outlet2'
'outlet3' 'outlet2'
2001 8 1 0 633.550 711.015
2001 8 1 1 632.090 710.980

which means there are two boundary conditons in the file ( 'outlet1' 'outlet2') but a third boundary conditon 'outlet3' is the same as 'outlet2' - see the Extran DOC file for more information. This was added to SWMM by Chuck Moore of CDM and it is a feature that we use extensively for complex continuous modeling.

Best Regards,

Robert Dickinson
DickinsonRE@CDM.COM