XP-SWMM version issues

Hi all:

I am working on a SWMM model developed and calibrated using XP-SWMM v8.01. We have since upgraded to v8.52.

The v8.52 node stages are up to 1.75 feet different than the v8.01 stages. While upgrades usually contain bug fixes and user-interface enhancements, we were surprised to see such a difference in stage results. Has anyone else run into this?

Thanks for your help,

Jeremy McBryan
jcmcbryan@pbsj.com

YES! I just asked Xp-software about the very same subject. It is maddening. Every time we upgrade the results totally change. I would like to supply our client with a reasonable explanation for the drastic changes in results, but they were unable to provide one.

Sorry, I know this forum is not to dump on any particular software/software vender. But this is almost like a public service announcement.

Mary Weber
MWeber@RWBECK.COM

Hi Jeremy,

Yes we did, for other basins we are working on, that you and PBS&J are not involved. We will probably have to recalibrate older model runs for the 8.52 or newer <sigh!>. Guess why I'm still in the office?

This has been a nightmare - we compared the results with previous versions and the stages of each upgrade have been different, too. I called XP-Software and they stated that those changes in stage are the result of engine improvements for stability. We have no real solution from XP-Software at this point, since we all want improvements for stability but at the same time I wish to have results that are consistent.

I wonder if other users noticed the same - maybe it's just us here in South-Flat-Florida. What about the pump routine? That also drove me nuts before I talked to you and Raul and heard that you were also having trouble with that.

Marcia B. Levinson
Levinm@miamidade.gov