XP-Swmm to EPA Swmm conversion

Hello,

I have been using xp-swmm for the past few years, but I have little
experience with EPA swmm. I have a client that would like a model I
developed in XP-SWMM to be converted into EPA swmm. I did the initial
conversion using a program I got from the user group called EPACONV.exe.
Then I deleted all the CJ lines because I think that they are not
needed. Anyway, the bottom line is the model is still not running to
completion and I'm having trouble pinpointing what the problem is. I'm
using SWMM44h.exe.

Thanks!
Mary Weber, P. E.

Mary,

The warning message you get at the end of the simulation is a difference
in how XP-SWMM and EPA SWMM treat the last value of the K3 line user
defined hydrographs in Extran. XP-SWMM adds another time value
internally so that the simulation does not run out of user defined
hydrograph values during the simulation. Your run of SWMM 44h is simply
reading this extra value on the K3 lines.

A more serious problem is the fact that you are using a large time step
in Extran. This is okay in XP-SWMM, which uses a variable time step,
but a problem in SWMM44h which uses a constant time step. You might
have to go to a time step of 1 seconds to run your model.

The CJ's lines should be ignored. There are a new feature of XP-SWMM
that I have not accounted for them yet in the converter.

Regards,
Bob Dickinson