EEMS 12.5.1 Release Notes

Release Date: 2026-08-18

EFDC+

Enhancements

QUICKEST for turbulence quantities — extended the QUICKEST advection scheme to the transport of turbulence quantities.
External density gradient in 2-cell channels — added flags to enable EDG for 2-cell channels.
Input error reporting — added further read-status checking when processing input files.

Bug Fixes

Dissolved oxygen saturation — fixed sign errors in the salinity correction of the Chapra (1997) saturation formulation, which suppressed saturation to roughly half its correct value at seawater salinity (3.24 vs 7.40 mg/L at 20 °C, 35 ppt). Saline cells appeared chronically supersaturated, driving spurious reaeration flux out of the water column. Freshwater results are unaffected.
Input file reading defects — spatially constant toxic partition coefficients were written to TOXPARW instead of TOXPARB; bed particulate organic carbon (STPOCB) is now zeroed across the whole array rather than a single cell and layer; fixed a malformed layer loop reading FPOCB.INP; fixed DYE.INP and the missing-layer fill for bed toxics (TOXB), which applied values to only one cell; FBODY now uses the standard input approach.
Open boundary aspect ratio check — the second cell in the aspect ratio test used the east neighbour instead of the west, north or south neighbour, in both the two- and three-time-level solvers.
Explicit nonhydrostatic pressure — the nonhydrostatic pressure loops used an unset layer index; they now use KC.
East/west wall drag — the calculation used the cell’s DY dimension instead of DX.
Courant number — corrected its computation in the QUICKEST transport scheme.
QUICKEST option handling — fixes to ISQUICK handling and the associated input initialization.
Wave calculations — corrections to the wind wave module, the two-time-level explicit solver and horizontal momentum diffusion.
Subgrid scale channels — fixed subgrid scale channel handling and reading of MODCHAN in MPI runs.
MPI broadcasts and indices — fixed several broadcast and array index issues.
OpenMP in turbulence advection — fixed an OpenMP issue in the advection of turbulence quantities.
Negative depth argument — fixed the negative depth argument in the water surface elevation solvers.
Bed thickness and void ratio — negative HBED and VDRBED are now avoided for all bed layers.
Wave bed shear stress — removed double counting of wave induced bed shear stress.
Bed surface radiation — corrected the zeroing of bed surface radiation in the heat module.
Propwash — fixed subgrid reporting for hard bottom cells.
Uninitialized variables — initialized global and local variables that could otherwise carry indeterminate values.

Infrastructure

Version bump from 12.5 to 12.5.1 across project files and version strings.

EFDC+ Explorer

New Features

Taylor Diagram

Enabled the Taylor Diagram for model skill assessment, available from the menu.

2DV Contours and Color Bar

Added a Color Bar Settings button in the Fill Color group, with min/max and interval values synced from the color bar.
Added Above-range and Under-range colors in 2DV Properties, following the selected color ramp and reverse setting.
Added a color ramp mode for contour lines, and major contour labels now stay visible when contour lines are off.
The color bar now shows and hides with the contour, and the legend no longer duplicates the layer when Fill Color and Color Bar are both active.
Contour values outside the level range are clamped before color interpolation for consistent out-of-range colors.

2DV View Toolbar

Renamed Data Settings to Layer Options, with a stacked-layers icon.
Added a Layer Properties dropdown listing layers by title; it opens that layer’s properties and stays greyed out until a layer is defined.
Added a legend tooltip describing the right-click options for layer settings and titles.

Distance Measurement in 2D View

Added two-click distance measurement matching the Grid+ tool, with a live readout and the measured length retained on the status bar. Line thickness increased for visibility.

Grid+ Enhancements

Added PNG image export, a Distance Precision setting, a scale bar Set Value option, and a User Guide link.
Increased the space allotted to the legend, and layers can now be reordered by drag and drop.

Coordinate Systems and EPSG

The EPSG code is now calculated from the UTM zone; EPSG codes are hyperlinked and ESRI codes were added.
Orthogonal Deviation is now computed correctly for geographic (lat/lon) grids, using WGS84 ellipsoidal radii of curvature so results match UTM grids.
Changing the model projection now warns before proceeding.

Lagrangian Particle Tracking

LPT layers can now be exported to shapefile.

External Density Gradient in 2-Cell Channels

Added the UI for the new EDG flags for 2-cell channels, matching the EFDC+ engine option.

Biota Group Type

Added a Type selector to the Biota form so the type can be set on an existing group — previously the only option was to add a new group and delete the untyped original. Selecting a type optionally loads its defaults, including zone 1 values.
The Type list and Add New presets are now driven by biota_defaults.jnp instead of a hardcoded list.
Fixed Reset to Default and Duplicate errors when no type or group existed; Reset to Default now also resets vertical migration values.

Usage Analytics

Added anonymous usage telemetry to help prioritize development. No model data or personal information is collected, and it can be disabled from the Other Settings tab of the Options dialog.

Plotting and Charts

Fixed corrupted x-axis tick and gridline display at year boundaries.
Fixed the series ID and name for constituent time series, and series names not loading from a Vertical Profile layout.
Fixed a blank Longitudinal Profile plot when loading from a layout, and the Selected Cells view disappearing after group selection changes.
Fixed reversed colors in several option forms and initialization of the chart label font form.
Depth can now be specified for the Extinction Coefficient in the Model Analysis time series form.
The report table is no longer shown after deleting a time series in External Forcings.

Grid and 2D View

Fixed multiple Grid+ undo/redo defects — undo now reverts only the edited layer, layers survive create/remove undo and redo, Remove Layers is undoable, and layers loaded from a project get a baseline so the first edit is reversible.
Fixed Delete Grid Nodes on projected (UTM) grids, and Delete and Extract Grid Nodes By Polygon for UTM polygons from non-KML overlays.
Fixed grid nodes reappearing after applying Ortho, and CVL_Grid export corrupting non-square grids.
Fixed single-cell and small-extent models rendering at the wrong scale, where a small Cartesian grid within valid lon/lat range was treated as geographic and reprojected.
Fixed Go To Cell zooming out to the whole domain, and Go To Cell and BC symbol sizing for geographic coordinates.
Fixed Grid+ DX, DY and Aspect Ratio on geographic grids, where the north-south dimension was foreshortened by latitude.
Fixed Fit to Land Boundary collapsing the boundary to the X-axis, and the Delete-mode cursor persisting after Ctrl+D / Ctrl+R.
Fixed a continuous repaint loop that re-rendered the whole 2D scene on every paint, leaving the view toolbar blank until the window was dragged.
Fixed the north arrow flickering and being painted over, a bitmap leak, and overlapping compass direction letters.
Fixed legend flicker during 2D animation (width is now held steady while animating), and the legend not refreshing on visibility toggle, which left two legends overlaid.
Fixed ghost trails from windows, dialogs, tooltips or the cell info label dragged across the 2D view.
Fixed the 2D view not repainting after a select-by-file, and Clear Selection doing nothing and showing no icon.
Fixed View Extent doing nothing when only an online background was loaded.
Fixed loading online backgrounds from Bing sources, and the online background tint when reordered below a colored layer.
Fixed the status bar coordinate display, grid outlines for 2DV, the Total Area display and the particle count display.
Fixed the scale bar disappearing after a Grid+ grid color change, and its value resetting after Set Value on any screen click.
Fixed the legend not restoring when re-showing a grid layer.

Model Input

Fixed loading newer EFDC+ decks that omit RKDYE and the NCBS/NCBW/NCBE/NCBN counts, which failed with “Error parsing card C46, line 1 in efdc.inp!”. Column order is now taken from the card header.
Fixed open boundary cells being claimed by an earlier group when two groups of the same type shared one pressure series, which split cells incorrectly and could drop a cell entirely.
Fixed an index out of range error when importing a data series: blank and whitespace-only lines (including Excel’s trailing tabs) no longer abort the import, lines missing the selected column are skipped, the detected rows-to-skip value is retained, and “Julian Date” is now an accepted time format.

Salinity and Temperature

Improved the layout of the Salinity and Temperature forms and their initial condition views.
The Temperature spatially varying factor selection is remembered between sessions instead of opening blank, and can no longer be typed into freehand.
Fixed a constant temperature initial condition not persisting with surface heat exchange enabled — the spatially varying checkbox was driven by the heat exchange option rather than the initial condition, forcing it on at every load. Unchecking the box now also flattens the initial condition.
Fixed HTBED1 being corrupted on load — it was rescaled alongside HTBED2 even though it is dimensionless and is never scaled on write. Models already saved with a rescaled HTBED1 must have the value re-entered.
HTBED2 is entered in m/s; values above 1E-5 m/s are almost always W/m²/°C typed by mistake, so the conversion is now offered on OK for confirmation instead of applied silently on the next load.
Fixed atmospheric settings being discarded on save when NASER = 0, including the spatially varying bed temperature flag. They now persist, with a warning that EFDC+ ignores them when no atmospheric data is present.

Sediment / Water Quality

Water Quality Kinetics Option changes are now written to the json file, and sediment diagenesis is initialized from constants in wq_3dsd.jnp.
Fixed the benthic flux table being lost when switching to specified spatially/temporally varying fluxes, which loaded an empty time block table even with wqbenflx.inp present and then overwrote the file on save. The existing file is now loaded, and the flux file name follows the fixed EFDC+ convention rather than being editable.
Fixed the WQICI import ignoring a file selected outside the model folder, with failures now reported rather than silent, and initial condition averaging using the bottom layer thickness for every layer, which weighted SGZ cells by the wrong volume.
Dissolved oxygen percent saturation is now computed as EFDC+ does, following the model’s own saturation formulation, elevation adjustment and offset settings, and including salinity. EE previously used its own sea-level freshwater polynomial, so saltwater and high-altitude models disagreed most with the kinetics that produced them.
Fixed dissolved oxygen layer units being overwritten when two DO display options were shown together — the options report different units but shared one parameter, which relabelled the mg/L layer as ”%”.

Layouts and User Interface

Fixed UI layout and controls clipped on the right edge on 4K / high-DPI displays, including distorted banner images.
Fixed the F2 help report — blank content in MDI views, the report opening twice in Grid+, a crash with no MDI parent, and a blank help window in installed builds where the viewer could not create its data folder under Program Files.
Grid+ Help now opens as a non-modal window above the main form, so shortcuts can be referenced while drawing.
The splash screen now shows version, license and copyright text when offline.
Fixed standalone GridPlus.exe failing to launch with a “You must install .NET Desktop Runtime” message, and restored its startup splash.
Fixed MP4 video export in installed builds, where the encoder libraries were bundled into the executable instead of placed alongside it.
Fixed an encoding issue affecting some symbols, and Horizontal Turbulence advanced values now display with consistent 7-significant-digit precision.
Updated the Array Out form UI.

Other

Removed the online data download features (boundary condition data and salinity initial conditions), as the upstream server data is no longer available; the remaining online data URLs were redirected.
EE version bumped from 12.5 to 12.5.1.

EEMS 12.5 Release Notes

Release Date: 2026-06-12

EFDC+

New Features

QUICKEST Transport Scheme

Added a new higher-order advection scheme for scalar transport, implementing the QUICKEST (Quadratic Upstream Interpolation for Convective Kinematics with Estimated Streaming Terms) algorithm. W-direction flux further refined in a follow-up update.

Enhancements

Input echoing to EFDC.OUT — Significantly expanded parameter echoing to improve run traceability and reproducibility.
Snapshot count reporting — Improved reporting of the number of output snapshots in EFDC.OUT.
Silica SA predation fraction — Added reading of the silica surface-area predation fraction parameter in the water quality module.
UV/VU advancement in 2TL — Minor fix to UV and VU advancement in the 2-time-level solver.
Small corrections and cleanup in the water quality module.

Bug Fixes

MPI water quality initialization — Fixed reading of wqici in MPI parallel runs.
Propwash without sediment transport — Fixed a crash/incorrect behavior when propwash is active but sediment transport is disabled.
Default HMIN — Changed the default minimum water depth (HMIN) to 0.01 m to improve stability for shallow-water applications.
Minimum bed thickness (HBEDMIN0) — Made HBEDMIN0 a global variable initialized to 1e-8 and added a guard to prevent use of unrealistically small bed thicknesses in contaminant calculations.

Infrastructure

Version bump from 12.4 to 12.5 across project files and version strings.

EFDC+ Explorer

New Features

QUICKEST Constituent Advection

Added Constituent Advection support for the QUICKEST numerical scheme.

Grid Generation Enhancements

Significantly improved telescoping grid generation.
Added rotation support to uniform grid generation.
New grid parameters are now retained in memory for reuse during iterative grid generation.
New grid settings are automatically saved to the #analysis folder when the model is saved.

2D Interpolation / Assignment (frmInterp2D)

Refactored 2D data interpolation and averaging for substantially faster processing.
Improved high-resolution data averaging when assigning to grid cells.
2D high-resolution assignment now preserves existing cell values when no new data is available, rather than overwriting them.
Added drag-and-drop support for point datafiles and polygon files directly into the form.
Made interpolation and assignment functions behave consistently across modes.

Drag and Drop / Image Handling

Overlay layers and georeferenced images can now be added via drag-and-drop.
Improved loading of large georeferenced images, with automatic downsampling in EE.

Plotting and Charts

Tick mark direction (in/out) is now configurable and persists across save/load.
Axis labeling now starts at the minimum value rather than the origin.
Added Min/Max controls for axes and fixed reverse-axis labeling.
Default export resolution raised to 300 ppi.
Fixed animation export and the stop-animation button.
General cleanup and reliability improvements to the XY plotting form.

Layouts and User Interface

Improved project layout save/load reliability.
Widened the save/load layout form for better usability.
New model control forms no longer fully overlap and use an increased cascade offset.
Fixed the greyed-out application taskbar icon at startup.
Fixed MDI child windows incorrectly maximizing when switching between windows.
Fixed cell border artifacts when surface-layer opacity is reduced.
Fixed pan behavior for 2DH models.
Labels no longer display while loading a file.

Model / Numerical Fixes

Fixed an off-by-one error when redistributing withdrawal/return and jet-plume layers.
Fixed an SGZ layering issue.
Fixed a Vegetation Profile (VP) issue and VP plotting for cells with only two layers.
Set HMIN to a consistent value of 0.01 m across EEMS.
Fixed uninitialized m_KL when changing layering for IGRIDV = 0.
Fixed a crash during Horizontal Turbulence initialization.
Fixed velocity reporting for 2DV.
Fixed reading of Open Boundary Conditions using differing pressure series within a single group.
Improved 2DH cell properties copy.
Fixed UTMZone handling when loading polygons in GridGen and other UTMZone issues.
Fixed background and mosaic tile refresh when zooming.

Sediment / Water Quality

Corrected Non-Cohesive and other sediment warning messages.

Other

EE version bumped from 12.4 to 12.5.
Improvements and build fixes for the console application.