In addition to Tony Kuch's answer regarding import into XP-SWMM, you should consider the following options:

1) MikeSWMM, which I suggested previously, uses the EPA SWMM4.4 engine, so no conversion is necessary. Your small model works with the free demo version of MikeSWMM. You would actually only need to use the MikeView post-processor, not the MikeSWMM pre-processor.

2) PC-SWMM, the lowest-cost commercial interface, also uses the EPA engine, so no conversion is necessary.

3) SWMM5 is free and has its own GUI. You'd need to run the conversion program to import your SWMM4-format input file.

Both PCSWMM and MikeSWMM thus read the external tide file you've already created. I haven't used SWMM5 much yet, but presume that it reads a tide file with an analogous format.

Regards, Mitch Heineman CDM

HeinemanM@CDM.COM