Release Notes

The release notes for HEC-HMS 4.12 can be found here.

New Features

  • Improved terrain data management
  • New infiltration method (generates excess runoff even when subbasin is not saturated)
  • New options for setting initial snow state variables
  • Variable ModClark option
  • "Default Values" and "Constant Value" are available for initializing gridded temperature index snow method 

Known Issues

The status of issues identified in the CWMS 3.4.1 release can be found here. 

The known issues as of the CWMS 3.5 release can be found here.

Fixed Bugs

Key bug fixes to highlight include:

  • No longer a slow down when re-running a forecast many times
  • Improved results tracking when editing HEC-HMS forecast parameters from CAVI
  • Intermittent issues when closing and opening forecasts
  • Some time-series, paired, and grid data were not being copied from the watershed to forecast directory when a new forecast was created
  • "Save to Base" can cause unintended consequences such as model linking or adding HEC-HMS variant information to the base HEC-HMS model; therefore, the "Save to Base" feature of the CAVI is no longer available for HEC-HMS by default. 
    • If it is truly desired and you are willing to take the chance with the issues it causes, "Save to Base" can be turned back on utilizing a -D flag. Please reach out to HEC to find out more.