Visual MODFLOW Flex 8.0 Product Release

March 23, 2022

Visual MODFLOW Flex – Integrated Conceptual & Numerical Groundwater Modeling Software

On March 23, 2022 we released Visual MODFLOW Flex 8.0, the latest version of the popular graphical user interface that brings together industry-standard codes for groundwater flow and contaminant transport, essential analysis and calibration tools, and stunning 3D visualization capabilities in a single environment. The conceptual model approach which is unique to Visual MODFLOW Flex in groundwater modeling user interfaces allows you to:

  • Build a conceptual model of the groundwater system, prior to the simulation – hydrostratigraphic structures, hydrogeologic properties, and boundary conditions are all designed outside the model grid or mesh; providing the flexibility to adjust your interpretation of the groundwater system before applying a discretization method and converting to a numerical model.
  • Build the model with minimal data pre-processing required – Working with grid-independent data allows you to maximize the use of your existing GIS data and incorporate physical geology and geographic conditions before designing a grid or mesh.
  • Generate and simulate regional and local-scaled models – With support for MODFLOW-LGR, you can design local grids around areas of interest, directly within the conceptual model environment. Calculated heads from a regional model can also be used as boundary conditions for local-scaled models.
  • Design the correct model faster – The grid-independent raw data is left intact and is not constricted by grid cells or mesh elements when modifying the data and project objective. This allows you to generate multiple numerical models from the same conceptual model.
  • Make changes to the model data and immediately see results – The conceptual model environment provides simultaneous 2D and 3D views which are updated whenever changes to the data are made.

Visual MODFLOW Flex Improvements

Visual MODFLOW Flex 8.0 includes the following major improvements:


You can now add more types of observations to your groundwater modeling projects:

  • Observation Types: the following observation types are now supported
    • Wells/Points: head, concentration
    • Boundary Condition Flow: net volumetric flow exchange between groundwater and a specified boundary condition
    • ZoneBudget Zone Flow: net volumetric flow exchange of groundwater in/out of a specified zone, between a specified zone and another zone or a specified boundary condition type
    • Stream (SFR): stage, depth, outflow, head difference between stream midpoint and associated groundwater cell centroid, flow diverted (diversion segments only), groundwater head, streambed seepage through the unsaturated zone
    • Lakes (LAK): stage, volume, inflow, outflow

Calibration and Run Result Visualization

Visual MODFLOW Flex includes a new model results dashboard to facilitate model calibration and results interpretation:

  • Model Dashboard: model observations and associated model results can be displayed in the new model results dashboard which includes dynamic tabulation and charting of results:
    • Tabulated results: observations and corresponding simulated results are presented in a tabular format with dynamic filtering.  Tabulated observations include observation metadata, including time, location, observation group/type, model layer, and conductivity zone, so that you can quickly display all the data or limit the view to what is relevant.
    • Charts: simultaneously display one or more charts including:
      • simulated vs observed values to evaluate model calibration/history matching
      • time series to display and evaluate transient result
  • Text Outputs: all observations and associated simulated results are output as tab separated variable text files for use in both Visual MODFLOW Flex and in external applications.
  • Flooded Cells: Display cells with simulated heads above the top of the model as a flood depth map or as a solid color to facilitate model calibration and interpretation:
Display cells with simulated heads above the top of the model as a flood depth map or as a solid color to facilitate model calibration and interpretation

Packages and Model Runs

Visual MODFLOW Flex 8.0 includes the following improvements for working with your models:

  • Single Engine Runs: run a secondary model such as transport, particle track, or zone budget simulation without having to rerun your flow model.
  • Update Solvers: update your flow model solvers without having to retranslate your whole model
  • Copy Property Zones: copy/paste zones from one material property zone type to another so that you can more easily have consistent material zones across property types such as conductivity, storage, and transport parameters
  • Default SMS Settings: the default settings for the SMS solver package in MODFLOW-USG have been updated based on recommendations by the author of MODFLOW-USG
  • Gage Package: gage package is supported in models using the surface water network workflows for streams (SFR) and lakes (LAK).

Data Handling

Greater control over your project modeling data:

  • Data Operations: data objects use the expression builder, facilitating greater control and flexibility when adjusting data object elevations for surfaces, points, polylines, and polygons.
  • Expression Builder functions: added a function called ifgaps() to handle expressions with non-overlapping surfaces – now you can combine surfaces with different extents/scales such as regional and site surfaces using a single expression.
  • Horizons: are now treated the same as other surfaces: they can be shown in 2D views with control over display settings
  • Cell Inspector Feedback: Typing a cell ID in the cell inspector provides (optional) feedback on where the specified cell is located in the active view
  • Export more data objects:
    • Grids: shapefile,
    • Output Comparisons: shapefile, contours, and surface
    • Horizons: surface
    • Water Table: surface

Performance, Usability, and Other Enhancements

Improved speed and performance for the following:

  • Loading and editing model properties and boundary conditions in larger models
  • Conceptual model conversion to numerical models using unstructured Q-Grids
  • Using the Cell inspector
  • Model Translation of Boundary Conditions

Greater control over your project modeling data:

  • Backup your project and related files as a zip file from the Main Menu to archive your project or easily share it with colleagues.
  • Generate all grid types from the Model Domain context menu of conceptual models
  • Define particles around screens of non-vertical wells in the 3D plane perpendicular to the well stem

Please see the Visual MODFLOW Flex Readme for a complete list of enhancements and defects addressed.