Release Notes

We strongly recommend that before you start using any new version of HEC-ResSim:

• make backup copies of your existing watersheds
• consider using separate modeling locations (folders) for your watersheds that are used with different versions of ResSim
  • for example you can have a directory for all watersheds that are
    • compatible with v3.3
    • compatible with v3.5
    • compatible with v4.0beta

As you use the new version:

• check the data in all elements of your model, being especially vigilant in reviewing your operation rules
• verify the operation of your current models with ResSim 3.3, and
• once satisfied with the results produced by the new version for each of your current models, make another set of backup copies. This second backup copy is suggested because when you open a watershed in ResSim 3.3, the format of key model files is changed, thus making the watershed unable to be opened with older versions of ResSim.

HEC-ResSim Releases

• ResSim 3.5 (Jul 2024)
• ResSim 3.3 (Feb 2021) along with the 3.3 User's Manual and Quick-Start Guide and Technical Notes
• ResSim 3.1 (Dec 2013) along with the 3.1 User's Manual and Quick-Start Guide and Technical Notes
• ResSim 3.0a (May 2007) along with the 3.0 User's Manual and Quick-Start Guide
• ResSim 2.0 (Sep 2003), along with the 2.0 User's Manual and Quick-Start Guide
• ResSim 1.0 and 1.1 were released to users internal to the Corps as part of the initial CWMS 1.0 and 1.1 releases (Sep 2001 and Jan 2002).
• NexGen Contracting Decision:  Leadership directed that the program would be led by HEC but all programming would be done by contract.
• ResSim inception ~ 1996
  

Prior to HEC-ResSim, there was HEC-5, which originated in the 1980's or earlier. The final release of HEC-5 was in 1998. HEC-5Q included water quality.

• HEC-5 (Version 8.0; October 1998)
• HEC-5Q, 1991 and possibly 1997.  no documentation can be found.