v.4.14.0 Release Notes

Initial Beta Release: 27 Feb 2026 

Final Version Release: TBD

New Features

Optimization Trial Enhancements

HEC-HMS now supports multi-target optimization, enabling calibration against multiple gage locations and distinct time windows within a single optimization trial. Users can define multiple objective targets—each associated with a specific basin element and evaluation period—and combine them into a single multi-objective search or execute them as sequential searches (e.g., upstream-to-downstream calibration). This enhancement allows modelers to leverage all available observed data, target specific hydrologic events or seasons, and implement more advanced calibration strategies without managing multiple, separate trials.

The user interface has been updated with a table-based objective editor and per-target results organization. A zonal optimization parameter framework has been implemented which enables scale-factor calibration across grouped subbasins. Furthermore, scale-factor implementations have been established for additional modeling methods including Linear Reservoir baseflow, Recession Constant baseflow, and Temperature Index snowmelt. Together, these improvements provide greater flexibility and a more powerful optimization framework for watershed calibration and operational forecasting.

Available Tutorial and Guide

A tutorial and guide is available that covers the new optimization capabilities in greater detail: Optimization Trial Enhancements

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 Kansas City District (NWK), Omaha District (NWO), and HEC staff (Mike Bartles, Tom Brauer, Avital Breverman, Alex Davis, Paul Ely, Matt Fleming, Greg Karlovits, Nick Van, and Josh Willis).

USGS Streamflow Importer

A new tool for importing USGS streamflow and stage data directly into HEC-HMS. Access it from the Components menu to query the USGS Water Data API for monitoring locations within a basin model boundary or shapefile. Specify a time range and frequency (daily or continuous), review matching sites in a results table, then import selected time series into HEC-DSS files with automatically created time series gages. The importer supports spatial filtering by basin geometry, time zone selection per site, customizable DSS pathnames, and optional USGS API key authentication.

More details regarding this new feature can be found here: USGS Streamflow Importer.

This feature was funded by the USACE Mississippi River Geomorphology & Potamology (MRGP) program. Initial code implementation and documentation were completed by Tom Brauer. Testing was completed by Ann Banitt (USACE-MVP, Grayson Holt, (USACE-MVM), and Gabby Tran (USACE-MVK), and Reuben Sasaki (USACE-RMC), in addition to Daniel Black and Mike Bartles.

Observed Flow Dialog

Coming beta.2

A new Observed Data dialog is now available under Parameters | Observed Data for assigning observed time-series gages to basin elements in bulk. The dialog displays all hydrologic elements in the selected basin model in an editable table with columns for Observed Flow, Observed Stage, and Observed SWE. Gage dropdowns are automatically sorted by geographic proximity to each element, placing the nearest gages at the top of the list. SWE assignment is available for subbasin elements. Modified assignments are highlighted with a change indicator and saved when the user clicks Apply. The table supports filtering by element type and sorting by hydrologic order or alphabetically.

More details regarding this new feature can be found here: Observed Data Dialog.

This feature was funded by the USACE Flood & Coastal R&D program. Initial code implementation and documentation were completed by Tom Brauer. Testing was completed by Lauren Coe.

Auto Reset Axis Extents on Compute

Coming beta.2

Result graphs now offer two new View menu options that control how plot axes behave after a compute:

• View | Auto Reset Y-Axis
• View | Auto Reset X-Axis

When enabled, the corresponding axis automatically resets to fit all data each time a compute completes. When disabled (the default), the existing zoom level is preserved.

The two options work independently -- you can auto reset just the Y axis to track changing magnitudes during calibration while keeping your X axis zoomed on a specific event window, or vice versa.

Each open graph window has its own independent setting, so you can configure different behavior for different plots at the same time. New graphs you open inherit the most recent setting you chose, and your preference is remembered between HEC-HMS sessions.

These options are available on element, subbasin, reach, reservoir, junction, diversion, source, sink, and optimized results graphs.

This feature was funded by the USACE CWMS National Implementation Program. Initial code implementation and documentation were completed by Tom Brauer. Testing was completed by Alex Davis and Matt Fleming.

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.

Enable Access to the Snowmelt Graphs within HEC-RTS

The ability to access the HEC-HMS Snowmelt plots directly within the HEC-RTS interface. This update require at least HEC-RTS 3.6 as changes were required in both applications. 

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 Avital Breverman, Paul Ely and Matt Fleming.

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 David Ho and Nick Van.  Testing was completed by Gregory Karlovits and Jay Pak.  

Upgrade Java Version to 21

HEC-HMS is written in the Java programming language.  v4.14 of HEC-HMS now utilizes Java 21, which has been designated as the current Java Long-Term Support (LTS) release as of February 2026.  This Java version provides significant advantages over Java 17 (the previous LTS) in concurrency, performance, and developer productivity.  This feature was funded by the USACE HH&C SET Program.  Initial code implementation was completed by David Ho, Mike Bartles, and Nick Van.

Snowmelt Parametric Aggregation Calculator (SnowPAC)

A new wizard tool has been added to HEC-HMS to aid in the rapid estimation of ATI-Meltrate functions for use in Temperature Index snowmelt modeling. The tool ingests daily time series data of snow water equivalent (SWE), temperature, and precipitation. The tool then allows the user to view and select distinct "melt events" and generate ATI-Meltrate functions based on historical events. ATI-Meltrate functions are exported back to the HEC-HMS project for immediate use in Temperature Index modeling. The tool also supports comparison of different ATI-Meltrate functions across multiple "melt events" for the same set of input time series, which aids in modeling decision making to identify suitable functions for different scenarios, such as wet and dry snowmelt years.

Additional information can be found in the Technical Reference Manual: SnowPAC: Snowmelt Parametric Aggregation Calculator

A tutorial and guide is available with a step-by-step walkthrough here: Estimating ATI-Meltrate using SnowPAC

This feature was funded by the USACE CWMS National Implementation Program and the General Investigations program. Initial code implementation and documentation were completed by Melissa Mika. Testing and code review were completed by Tom Brauer and Mike Bartles.

Mandate HEC-DSS upgrade from v6 to v7

From HEC-HMS v4.14 onward, HEC-DSS v6 files are no longer supported. When opening an existing project in HEC-HMS v4.14, users will be prompted to migrate the project’s DSS files. If the user declines to migrate, the project will not open in v4.14.

Add new version of the Maricopa County Green-Ampt tool

The existing Maricopa Green-Ampt parameter estimation tool is based on the 2018 Maricopa County Hydrology Manual which follows methodology in Rawls et al (1983). 

The existing tool remains available, but a new Green-Ampt parameter estimation tool now exists that is based on the 2023 Maricopa County Hydrology manual which follows methodology in Saxton and Rawls (2006). The tool launches a wizard where the user can specify land use and soil shapefiles and lookup tables. The data are used to calculate parameter estimates for initial deficit, wetting front suction, soil conductivity, percent impervious, and max canopy storage. Upon completion of the wizard, the Green & Ampt and Simple Canopy Global Editors are automatically updated with the parameter estimates.

A tutorial and guide demonstrating Maricopa parameter estimation tools can be found here: Maricopa County Green-Ampt Parameter Estimation Tool

This feature was funded by Maricopa County, Arizona. Initial code implementation and documentation were completed by Josh Willis. Testing and code review were completed by Nick Van and Tom Brauer.

Read 2D Meshes created in HEC-RAS v6.4+

2D meshes created in HEC-RAS v6.4 through HEC-RAS v7.0 can now be imported and used.  All cell shapes, including quadrilateral, cartesian, and triangular, are supported.

This feature was funded by the USACE HH&C SET Program. Initial code implementation and documentation were completed by Mike Bartles. Testing was completed by Paul Ely and Mike Bartles.

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.

Area Reduction in Frequency Storm produced error with Subbasin Area method

The TP-40 area reduction method produced an error when the Subbasin Area was selected as the storm area method. This issue was introduced in v.4.13 and fixed in v4.14-beta.1.

Area Reduction in Frequency Storm allows negative storm areas

Negative storm areas were incorrectly permitted in the User-Specified storm area in the Frequency Storm method when using Area Reduction. This issue was found in v4.10 and fixed in v4.14-beta.1.

Write Grid Validation Errors

When a grid is determined to be invalid, the reason for it being found invalid was not written to the user display. Code was added to write the error message to the user display. This issue was introduced in v4.13 and fixed in v4.14-beta.1.

Compute progress dialog stops short of 100%

For some simulations, the compute progress dialog incorrectly stopped short of 100% even on successful computes. This user-interface bug was caused by an incorrect tally of the number of compute items to be computed. This issue was introduced in v4.9 and fixed in v4.14-beta.1.

Optimization parameter results plots do not show last iteration value

Optimization Trial computes are designed to compute a last iteration with the optimized parameter set (if convergence is achieved). The last value of the optimization parameter plots did not correctly show the value from the optimized parameter set. This issue was introduced in v4.9 and fixed in v4.14-beta.1.

Manual entry gage units not saved when no data is entered

Units for a manual-entry gage were not persisted (saved) when the gage contained no entered data. This has been corrected so the selected units are retained even if no data values are provided.

Manual entry gage units displayed incorrectly in the UI

In rare cases, the units shown in the UI for a manual-entry gage could reflect units from an older DSS record after the gage time window was changed. This has been updated so that the UI more consistently displays the user-selected units.

Incorrect Uncertainty Analysis results for non-gridded basin models with non-meteorologic uncertainty variables

Fixed an issue that could produce incorrect Uncertainty Analysis results when a basin model is not made up entirely of gridded subbasins and the selected uncertainty variable is not meteorologic.

Unit selection was not preserved in Precipitation-Normal and Precipitation-Frequency grids with scale factor not equal to 1

Unit selection reset to default in the grid editor for Precipitation-Normal Grids and Precipitation-Frequency Grids when the scale factor was not equal to 1. This issue was introduced in v4.13 and fixed in v4.14-beta.2.

Disallow Save States when using select subbasin, reach, and/or reservoir sediment methods

Save states functionality has not been implemented for all Subbasin, Reach, and Reservoir sediment methods. Now, an error message is thrown when a compute is triggered, save states is enabled, and unsupported modeling methods are being used.  This issue was introduced in v4.0 and fixed in v4.14-beta.2.

Simulation aborts when sediment grade scale is changed

A simulation would abort with an unknown error when the sediment grade scale was changed in the basin model. This issue was introduced in v4.13 and fixed in v4.14-beta.2.

Text areas now support pasting multi-line content

Previously, pasting text into description and notes fields would discard everything after the first line, keeping only the first line of the pasted content. Multi-line text can now be pasted in full, preserving all lines as expected. This issue was introduced prior to v4.4 and fixed in v4.14-beta.1.

Restrict data transformation to "No Transformation" for response objective functions

Within the Optimization Trial, users could previously set response objective functions (e.g., maximize flow volume, peak flow, peak stage, or total precipitation) to a data transformation type other than "No Transformation". This was a UI bug; the setting was never saved to disk and no transformation was applied during compute. Restrict the allowable transformation types in the UI to only "No Transformation" for response objective functions. This bug was introduced prior to v4.12 and fixed in v4.14-beta.2.

Make crop coefficient label display as a required parameter

Previously the crop coefficient label was displayed within the user interface as an optional parameter.  Now the label correctly displays as required.  This issue was introduced in v4.12 and fixed in v4.14-beta.2.

Uncertainty Analysis parameter is greyed out in the results after it is re-computed

Uncertainty Analysis results were showing as unavailable after recomputing. This issue was introduced in v4.14-beta.1 and fixed in v4.14-beta.2. 

Make maximum release and maximum capacity labels display as not required parameters

Previously the maximum release and maximum capacity labels were displayed within the user interface as required parameters.  Now the labels correctly display as not required.  This issue was introduced in v4.11 and fixed in v4.14-beta.2.

Station ID not saving in Discharge Gages

Previously the user-input Station ID was not saving upon closing and reopening the project. Now the Station ID is correctly saved and loads upon reopening the project. This issue was introduced in v4.13 and fixed in v4.14-beta.2.

Unit system not updating on External Subbasin Panels

Previously the external subbasin editor panels were not observing the units change within the Basin Model for Surface, Canopy and Deficit and Constant Loss. Now the unit system is appropriately updated for those methods. This issue was introduced prior to v4.11 and fixed in v4.14-beta.2.

Gridded Parameter Edits Now Marked as Modified

Previously, when you edited gridded parameter values, the data was saved to the basin database, but the basin model was not marked as modified. As a result, there was no "DATA CHANGED, RECOMPUTE" indication in results plots. Gridded parameter edits now correctly propagate change notifications to the parent subbasin, so the basin file reflects a modified state and subsequent computes recompute affected elements. The following methods were affected: Gridded Simple Canopy, Gridded Simple Surface, Gridded Deficit Constant, Gridded SCS, Gridded Green and Ampt, and Gridded Soil Moisture Accounting. This issue was introduced in v4.13 and fixed in v4.14-beta.2.

Uncertainty Analysis parameter drop-down selection could hang for parameters without unit systems

In Uncertainty Analysis, the parameter selection drop-down could hang after the analysis was computed at least once, when switching to parameters without an associated unit system (for example, Hypothetical Storm:Area Reduction Function or Compute Specification). This issue was introduced in v4.13 and fixed in 4.14-beta.2.

Initial Storage Depth parameter for Simple Surface did not convert when basin units were changed

Changing basin units didn't update the value of the Initial Storage Depth parameter for Simple Surface method. This could result in different computed values if the unit system is changed. This issue was introduced in v4.12 and fixed in v4.14-beta.2.

This correction will change computed results.

Apply scale factors in Variable Parameter Clark

During optimization trial iterations, the Variable Parameter mode of the Clark unit hydrograph and ModClark transforms did not apply the time-of-concentration or storage-coefficient scale factors when computing per-period Tc and R, even though the constant-parameter mode did. Optimization Trials varying an All-Subbasin scale factor over a Variable Parameter Clark or ModClark transform stored the new value on every subbasin but produced an unchanged hydrograph at compute time, so the objective function was flat with respect to the search variable and the trial never converged. This issue was introduced in v4.11 and fixed in v4.14-beta.2.

Reset residual runoff in Variable ModClark gridcells

Basin models using Variable ModClark grid cells could store stale residual runoff from the end of the previous simulation. For optimization trial iterations, this stale residual runoff could show up as perceived initial baseflow in subbasin outflow plots even when the baseflow method was set to "–None–". This issue was introduced in v4.12 and fixed in v4.14-beta.2.

Reset residual runoff in Variable ModClark gridcells

Basin models using Variable ModClark grid cells could store stale residual runoff from the end of the previous simulation. For optimization trial iterations, this stale residual runoff could show up as perceived initial baseflow in subbasin outflow plots even when the baseflow method was set to "–None–". This issue was introduced in v4.12 and fixed in v4.14-beta.2.

HDF File Errors When Importing New 2D Meshes

When opening a project that included several subbasins that utilized the 2D Diffusion Wave transform, exceptions were thrown when importing a new 2D mesh. This issue was introduced in v4.13 and fixed in v4.14-beta.2.

Beta Releases

beta.1 release: 27 Feb 2026 

The following table presents features that were added and bugs that were fixed within each beta release.

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