v.4.14.0 Release Notes

Initial Beta Release: TBD

Final Version Release: TBD

New Features

Add checkbox toggle option for blending

Added a checkbox to the forecast blending table to allow for enabling / disabling blending for each element. Previously entered blending parameters are saved even if the "Enable" checkbox is unselected (in disable mode). Parameters are permanently erased if the Blending Method selection is set to 'None'.

More information pertaining to the use of Forecast Blending can be found here: 

Blending Computed and Observed Flow

This feature was funded by the USACE CWMS National Implementation Program. Initial code implementation and documentation were completed by Josh Willis. Testing was completed by Lauren Coe, Alex Davis, and Nick Van.

Enable the Combined Parameter Editor

The Combined Parameter Editor is a tool that allows for extremely efficient model calibration when performing forecasting. This tool allows users to access to all loss, transform, baseflow, and snow parameters that are in use within the active Forecast alternative within a single window. Additionally, automatic baseflow, reach, and reservoir initialization; automatic reservoir reset; and blending options are also included within the Combined Parameter Editor, as shown in the following image.

In previous versions, the Combined Parameter Editor was only accessible through HEC-RTS. Within v4.14, this feature has been made accessible from the native HEC-HMS user interface.

More information pertaining to the use of Forecast alternatives and the associated calibration tools can be found here: 

Forecast Parameter Adjustments

Subbasin Baseflow Initialization

Reservoir Pool Initialization and Reset

Blending Computed and Observed Flow

This feature was funded by the USACE Corps Water Management System (CWMS) National Implementation Program. Initial code implementation and documentation were completed by Mike Bartles. Testing was completed by Alex Davis and Nick Van.

Modify selection of check boxes in forecast editors

Check boxes within forecast editors take a single click to enable/disable the button. In version 4.13, this took multiple clicks for selection. 

This feature was funded by the USACE Corps Water Management System (CWMS) National Implementation Program. Initial code implementation and documentation were completed by Alex Davis. Testing was completed by Nick Van.

Remove and relocate select CAVI action buttons

The Forecast Configuration and Zone Configuration buttons were removed as forecast action buttons in the CAVI. The Calibration Summary Table button was moved to the Reports tab from the Actions tab. 

This feature was funded by the USACE Corps Water Management System (CWMS) National Implementation Program. Initial code implementation and documentation were completed by Alex Davis. Testing was completed by Paul Ely and Mike Bartles.

Frequency Storm frequency depth interpolation selection

The Frequency Storm meteorological method allows users to choose an interpolation method between frequency depths.  The Interpolation Selection option lets you choose Log, Semi-Log, or Linear interpolation and will interpolate between frequency depths.  

Available Tutorial & Guide

A tutorial and guide is available demonstrating the interpolation feature: Frequency Storm Interpolation Options

This feature was funded by the Hypothetical Storms Research and Development Work Unit. Initial code implementation and documentation were completed by David Ho. Testing was completed by Lauren Coe, Nick Van, and Tom Brauer.

Add multiple output time interval capability to output control dialogs

Previously in HEC-HMS, only one output interval was allowed per element time-series type. A right-click "Duplicate Row" option has been added so that users can specify two (or more) output intervals per element time-series type. This functionality has been added to Output Control Dialogs within 

a Simulation Run, Forecast Alternative, Optimization Trial, Uncertainty Analysis, Depth-Area Analysis, and Ensemble Analysis. Changing the output to "Selected" and then pressing the gear button, as seen below, launches the output dialog. Each row can be duplicated (and subsequently deleted) by right-clicking on it.

Selections are saved to the ".run" file in the main project directory for simulation runs, and to the appropriate sub-directory folder for each of the other compute types (i.e. the ensemble analysis output selections are saved to the "ensemble/.ens" file).

The results plots and tables located on the "Results" tab in HEC-HMS function exactly as before. If multiple output intervals were selected prior to compute, the plots and tables will be populated with the shortest output interval data. However, all output intervals, even multiples, will be written to the simulation DSS file.

This feature was funded by the FIRO program. Initial code implementation and documentation were done by Josh Willis. Review and testing were completed by Josh Willis, Matt Fleming, and Tom Brauer. 

Enable specifying sediment transport potential and sediment settling velocity methods separately for individual basin elements

The following sediment transport methods can now be selected at the individual element level: Sediment Transport Potential, Cohesive Transport Potential, Fall Velocity and Hindered Settling Velocity. Previously, these methods were set from a basin's Sediment tab for all the elements in a given basin. In 4.14, these methods can be set for each element individually from each element's Sediment tab or from the corresponding global editors.

This work was funded by the U.S. Army Corps of Engineers Post‑Wildfire Research and Development Program (Hydraulics & Hydrology work unit). Initial code implementation and documentation were completed by Paul Ely, David Ho, and Natasha Sokolovskaya. Testing was completed by Jang (Jay) Pak. We also thank Jackie Oehler (SPL) for testing support. 

Allow sampling of hypothetical storm spatial pattern in uncertainty analysis

Spatial Pattern for Hypothetical Storm was added to the parameters that may be sampled in an Uncertainty Analysis.

This feature was funded by the Flood and Coastal Systems R&D program's Hypothetical Storms work unit. Initial code implementation and documentation were completed by Paul Ely. Review and testing were completed by Greg Karlovits, Daniel Black, and Natasha Sokolovskaya.

Sample initial state for uncertainty from time series computed by a simulation run

Initial states for an Uncertainty Analysis can be sampled from time series computed by a period-of-record simulation. Given a list of dates, initial states for a realization can be sampled based on the date associated with the realization.

This feature was funded through the FEMA FFRD initiative, a series of studies intended to help FEMA achieve their goals of developing a risk informed NFIP. Initial code implementation and documentation were completed by Paul Ely. Review and testing were completed by Greg Karlovits, Daniel Black, and Nick Van.

More information pertaining to the use of setting initial states from continuous time series can be found here: 

Uncertainty Analyses

Add Observed Storage and Observed Inflow to Reservoir Elements

A new gage type - Storage Gage - has been added. Reservoir elements can use the new gage type for modeling observed storage for their reservoir elements. Additionally, reservoirs now differentiate between Observed Outflow and Observed Inflow. Previously, reservoir elements could only utilize one observed flow hydrograph (corresponding to outflow).

This feature was funded by the USACE CWMS National Implementation Program. Initial code implementation and documentation were completed by Daniel Black. Testing was completed by Paul Ely, Alex Davis, and Nick Van.

Generalized vector data reader improvements

The vector data reader framework in HEC-HMS was expanded to support reading single geometries sequentially, enabling more efficient processing pipelines. The terrain reconditioner feature now uses this capability to simplify and reproject geometries in parallel, improving performance on large datasets.

The reader framework now implements AutoCloseable, requiring callers to use try-with-resources to ensure safe cleanup. Error handling was also improved. Geometry read failures are now logged consistently, and user-facing workflows (e.g., wizards) display formatted error messages when read exceptions occur.

This feature was funded by the Maricopa County Flood Control District. Initial code implementation and documentation were completed by Josh Willis. Review and testing were completed by Mike Bartles and Tom Brauer.

Add Reservoir Evaporation to Specified Release Routing Method

Reservoir evaporation can now be computed when using the Specified Release Routing Method. Previously, evaporation from the reservoir element could only be computed using the Outflow Structures or Rule-Based Operations routing methods.

This feature was funded by the USACE CWMS National Implementation Program. Initial code implementation and documentation were completed by Lauren Coe. Testing was completed by Paul Ely, Alex Davis, and Josh Willis.

Add Rating Curve Option for Dam Tops and Outlets

Outflow from a reservoir dam top or outlet can now be defined using an elevation-discharge paired data table. Previously, this option was only available for a structure defined as a spillway on the reservoir. 

This feature was funded by the USACE HH&C SET Program. Initial code implementation and documentation were completed by Lauren Coe. Testing was completed by Paul Ely and Melissa Mika.

Add Copula for Correlated Sampling in the Uncertainty Analysis Compute Type

The Uncertainty Analysis compute type supports copulas to enable correlated sampling among basin parameters and/or rainfall depth. Two copula options are available: Gaussian and Student’s t. This feature was funded by the Hypothetical Storms Research & Development. Initial code implementation and documentation was completed by Gregory Karlovits and Jay Pak.  

Bugs Fixed

Incorrect computation of coefficient of variation in Modified Kling-Gupta Efficiency

The coefficient of variation was incorrectly computed in the Modified Kling-Gupta Efficiency. The computation was corrected. This issue was introduced in v4.13 and fixed in v4.14-beta.1.

This correction will change computed results.

Incorrect unit for 15-minute rainfall intensity in USGS Emergency Assessment Debris Yield Method

The 15-minute rainfall intensity unit in the USGS EA Debris Yield method was incorrect (depth/15-min). It has been corrected to depth/hr. This issue was Introduced in v4.13 and fixed in v4.14-beta.1.

This correction will change computed results.

New style basin editors and select global editors don't observe changes in project decimal separator

Basin component editors did not observe decimal separator changes from program settings. This issue was introduced prior to v4.12 and fixed in v4.14-beta.1.

Krone-Partheniades cohesive transport potential calculation not properly checking whether sediment is erosive

When computing Krone-Partheniades Cohesive Transport Potential, the check for whether the sediment is erosive was always returning false and the cohesive potential was not correctly adjusted. This issue was introduced in 4.4 and fixed in v4.14-beta.1.

This correction will change computed results.

HMS force-closed when attempting to run 2D Sediment method with Sediment Delivery Ratio Transport Potential method

Stop compute and produce an error message if attempting to run 2D Sediment method with Sediment Delivery Ratio Transport Potential method selected in basin sediment properties tab. SDR method is not compatible with 2D Sediment. Previously, HMS would close with no messages if this combination was attempted. This issue was introduced in 4.11 and fixed in v4.14-beta.1.

Update title in the Windows console

In previous versions, when running HEC-HMS using a .cmd, the console title was erroneously showing "4.9".  This has been fixed to use a title of "4.14". This issue was introduced in v4.9 and fixed in v4.14-beta.1.

Correctly Enable Combined Parameter Editor Functionality

In past versions, various Combined Parameter Editor functions were enabled incorrectly.  This has been fixed such that only pertinent functionality is enabled based upon Basin Model and Forecast Alternative options.  This issue was introduced in v4.4 and fixed in v4.14-beta.1.

Canopy and Surface States Were Not Saved for Gridded Subbasins

Canopy and surface states were not saved for a gridded subbasin. A simulation that was intended to be initialized using a saved state wrote a warning message, and the canopy and surface was initialized using the input initial values for the subbasin instead of saved state values. This issue was introduced in v3.1 and fixed in v4.14-beta.1.

This correction will change computed results.

Expression calculator does not work for Gridded Simple Surface and Gridded Simple Canopy

The expression calculator failed to compute in Gridded Simple Surface and Gridded Simple Canopy global editors. This issue was introduced with the Specified Values Gridded Parameterization feature in 4.13 and fixed in 4.14-beta.1.

Time series gage duplicated when renaming in time series data manager

Renaming time-series gage in time series data manager duplicated the gage. This issue was introduced in v4.13 and fixed in v4.14-beta.1.

Tabbed global editors not updating with Maricopa parameter estimates

After using a Maricopa parameter estimation tool, i.e. for Clark Unit Hydrograph parameter estimation, the global editor was opened to the wrong tab and the editor was not populated with estimated values. This issue was introduced in v4.13 and fixed in v4.14-beta.1. 

Default forecast sometimes uses alternate variant data source

If the default forecast was computed after computing an alternate variant forecast, the default forecast incorrectly used the variant data source information (i.e. grids and gages from the alternate variant forecast). This issue was introduced in v4.13 and fixed in v4.14=beta.1.

Maricopa parameter estimation tools return NaN for some parameters

The geometry read and geometry intersection logic in HEC-HMS has been improved to handle geometries of type Polygon, MultiPolygon, and GeometryCollection. Furthermore, the intersection logic has been parallelized for enhanced performance and better handling of large vector datasets. Some of the Maricopa parameter estimation tools in HEC-HMS that rely on intersecting geometry data such as subbasin, soil, and landuse boundaries are now more robust and performant. These issues were introduced in v4.9 and fixed in v4.14-beta.1.

Compute breaks when observed reservoir pool elevation is linked to invalid gage data

Invalid (e.g. unidentified units) time-series data for observed reservoir pool elevation would break the compute with an error. The compute does not need valid observed data to proceed. The issue was fixed by completing the compute and addressing invalid observed data with a warning. This issue was introduced in v4.13 and fixed in v4.14-beta.1.

Error in Toffaleti sediment transport method

There was an error in temperature conversion that caused incorrect results when calculating transport potential in the Toffaleti transport method. This issue was introduced in v4.4 and fixed in v4.14-beta.1.

This correction will change computed results.

Channel parameters caused problems in uncertainty analysis

Certain channel parameters caused problems when they were used as parameters in an uncertainty analysis. Although the analysis appeared to compute, results could not be displayed, and the analysis could not be loaded from a file. This issue was introduced in v4.4 and fixed in v4.14-beta.1.

Optimization Trial fails with short output buffer length setting

Some Optimization Trials that computed successfully with a long output buffer length setting (i.e. 50,000) would fail when computed with a shorter output buffer length (i.e. 500). This issue was introduced in v4.13 and fixed in v4.14-beta.1.

Normal depth global editor fails to open after importing reaches

The normal depth global editor failed to open after importing reaches from a GIS file. This issue was introduced in v4.10 and fixed in v4.14-beta.1.

Wrong SI units for shear stress in Krone-Parthenaides Transport

Prior versions used kg/m2 for shear stress. The SI units for shear stress have been changed to Pascals. This issue was introduced prior to v4.4 and fixed in v4.14-beta.1.

This correction will change computed results.

Missing and incorrect sediment time-series results for 2D sediment models

In the "2D Connection" results folder, sediment load time-series values were off by an index of 1. This off-by-one error was introduced in v4.13 and fixed in v4.14-beta.1.

In the "2D Connection" results folder, only sediment load time-series results were provided for 2D connections. Now, sediment volume and bulk-flow time-series are provided for each 2D connection element. These time-series results have been missing since their original introduction into HEC-HMS in v4.11, but are now present in v4.14-beta.1.

In the "Sediment" results folder, the bulk-flow time-series was incorrectly using subbasin baseflow in its calculations instead of the total outflow. This incorrect behavior only pertained to 2D sediment models. Now, this bulk-flow time-series correctly represents an accumulation of the total outflow and sediment volume from each 2D connection element. The incorrectly reported bulk-flow time-series for 2D sediment models was introduced in v4.11 and fixed in v4.14-beta.1.

This correction will change computed results.

Open Uncertainty Analysis results plot fails to update after re-compute

Previously, immediately after a compute, uncertainty analysis results were incorrectly saved with a previous execution time. This resulted in open plots being updated with an incorrect "DATA CHANGED" label and with stale results. Now, the uncertainty analysis execution time is correctly updated immediately after a compute. This issue was introduced in v4.13 and fixed in v4.14-beta.1.

Inconsistent UI display and behavior with Surface Method and Kinematic Wave

The Kinematic Wave Runoff method and Surface Method showed inconsistent UI display with Surface 2 appearing before Surface 1 and users could not input different parameter values between Surface 1 and Surface 2 tabs.  This issue was found in v4.12 and fixed in v4.14-beta.1.

Open internal time-series results plots fail to update after re-compute

Previously, open internal time-series results plots (embedded in the bottom-left corner of the user interface) failed to update after a recompute. Instead, stale results were displayed. This issue was introduced prior to v4.4 and fixed in v4.14-beta.1.

Linear Reservoir Initial Discharge parameter doesn't update when changing unit systems

When changing the Basin Model unit system, the Linear Reservoir baseflow Initial Discharge parameter did not update correctly when used in combination with the 2D Diffusion Wave transform method.  This issue was introduced within v4.8 and has been fixed in v4.14-beta 1.

Metric flow units not displaying correctly in discharge time-series gage

Metric flow units (m3/s) were displayed as "Invalid" in the flow gage editor for time-series discharge gages with DSS File data source. This issue was introduced in v4.13 and fixed in v4.14-beta.1.

Avoid errors when reading 2D mesh information from an HDF file

Occasionally, errors would be encountered when reading 2D mesh information from an HDF file. This issue was introduced in v4.13 and fixed within v4.14-beta.1.

Data source for time-series gages created pre-v.4.1 reverted from DSS file to Manual 

Time-series gages with external DSS file source created in HEC-HMS v.4.1 or earlier did not properly import into the latest HEC-HMS version, reverting the file source to Manual. This issue was introduced in v4.13 and fixed in v4.14-beta.1.

Duplicate tabs were added when switching methods in subbasin editor

Duplicate tabs were created for some Canopy, Loss and Transform methods when selecting the methods out of the subbasin editor opened by double-clicking the element on the map. This issue was introduced in v.4.12 and fixed in v4.14-beta.1.

Beta Releases

beta.1 release: TBD

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