Release Notes

The release notes for HEC-ResSim 4.1.0 can be found here.


Model Linking

  • Improvements made to the "Get Linkages From" Option in the Model Linking Editor for HEC-ResSim. The "Use Existing ResSim Linkages" will overwrite the current linkages with the pathnames contained in the HEC-ResSim - Default variant. This is helpful if the user makes an update in the base HEC-ResSim alternative and needs to update to new DSS pathnames. 

Variants

New Features

  • New OSI Table Fill Options
  • New On-The-Fly (OTF) Fill Editor
  • New Observed Data addition in the OSI Variable Editor
  • In situations where multiple HEC-ResSim alternatives are present in a Forecast, the active HEC-RTS Forecast Run (checked box in the Forecast Window) now is synced with the Active HEC-ResSim Alternative. 
  • New check for coincidental zone definition.  ResSim will not run if zones cross or overlap and will give an error that was not seen in 3.51.  This can be addressed by identifying a "Zone Sort" Order for zones that are functions of something other than date.  Once ResSim has a zone sort order, it will manage conflicts without further ado.  See:  Reservoir Operation Zones.

Known Issues

The known issues and their statuses as of the CWMS 3.6 release can be found here.

Workarounds

Key workarounds to highlight include:

HEC-RTS 3.6 includes HEC-ResSim 4.1.2, the first HEC-ResSim from the version 4.x line to be included.  There are a handful of internal changes and scripting API changes from HEC-ResSim 3.5.1 to HEC-ResSim 4.0 that may impact scripts in HEC-ResSim models.

  • HEC-ResSim 3.5.1. was the last version of HEC-ResSim to use the hecjavadev  dependencies, with HEC-ResSim 4.0 and forward having moved to the HEC monolith  shared code libraries.  Scripts inside of HEC-ResSim that depend on these library may need import statements and some API calls changed.  A summary of the changed library names is listed in the HEC-RTS 3.3 release notes.
  • (warning)  A major API change between HEC-ResSim 3.5.1 to HEC-ResSim 4.0 was the availability of unregulated flow through the network.getTimeSeries() function call.  As a result, an additional parameter may need to be added.
    • In the scripting editor's API tree, the model variables now have an added level in the hierarchy for regulated (`reg`), unregulated (`unreg`) and cumulative local (`cumloc`) flow time series.  Previously only the regulated flows could be accessed via this tree.
    •  
    • In an existing model script that uses the network.getTimeSeries(...)  API call, you will need to add a new string as the last parameter.  For existing scripts, this will need to be "reg"  with a few exception noted below.  As an example, in an existing script, code that says network.getTimeSeries("Junction","Big River at Down Town", "", "Flow", "reg")  will become network.getTimeSeries("Junction","CCP1", "", "Flow", "reg") , with the added parameter at the end to specify which time series is being requested.
    • A known issue in ResSim 4.1.2 is that certain model variables that only exist in the regulated compute, such as "Elev-ZONE" time series do not populate correctly from the API tree.  For example, network.getTimeSeries("Reservoir","Hundred Foot Dam", "Conservation", "Elev-ZONE", "") requires an empty string as the last parameter, while the API tree currently populates it with "reg" , which results in a None object being returned, and likely causing a NoneType  exception to occur in running the script.   This issue has been fixed in HEC-ResSim 4.2 such that the string "reg"  returns a valid time series.