Welcome to FEFLOW

Thank you for choosing FEFLOW! You have selected one of the most com­prehensive, well-tested and reliable programs for the simulation of flow, groundwater age, mass- and heat-transport processes in porous media. This manual explains FEFLOW’s extensive modelling capabilities so that the easy-to-use intuitive graphical user interface can be used to its full potential. Please take your time to familiarize yourself with the software to ensure max­imum productivity and efficiency in your projects.

The FEFLOW Package

The FEFLOW 8.1user interface supports the entire workflow from preprocessing via the simulation run to postprocessing. In addition, there are a number of supporting applications for specific purposes:

  • FePEST: A convenient graphical user interface for using PEST by John Doherty with your FEFLOW models for parameter estimation, uncertainty analysis and much more. FePEST runs with a FEFLOW license.

  • FEFLOW Viewer: Free visualization and postprocessing tool for FEFLOW files.

  • Command-Line Mode: In command-line mode, FEFLOW runs without any graphical user interface. This is especially useful for batch runs or integration into other simulation environments.

  • WGEO: a geo-imaging software. Its most important fields of application in connection with FEFLOW modeling are georeferencing of raster maps and coordinate transformation.

  • FEPLOT: As FEFLOW itself does not provide printing capabilities, FEPLOT can be used to create plot layouts and print maps composed of vector maps, graphi­cal elements, and text.

  • FE-LM2: This tool provides functionality for curve fitting, e.g., for obtaining the parame­ters for parametric relationships in unsaturated flow or for sorption isotherms.

FEFLOW Documentation

The FEFLOW 8.1 documentation provides an introduction to the practical appli­cation of the software as well as a detailed description of the underlying con­cepts and methods.

The comprehensive book “FEFLOW – Finite Element Modeling of Flow, Mass and Heat Transport in Porous and Fractured Media” written by H.-J. G. Diersch represents a theoretical textbook and covers a wide range of physical and computational issues in the field of porous/fractured-media modeling. The book is general and will be useful for both students and practitioners in engineering and geoscience as well as in other fields where porous-media flow dynamics and computational methods are of specific concern.

The book starts with a more general theory for all relevant flow and transport phenomena on the basis of the continuum approach, systematically develops the basic framework for important classes of problems (e.g., multiphase/mul­tispecies non-isothermal flow and transport phenomena, discrete features, aquifer-averaged equations, geothermal processes), introduces finite-ele­ment techniques for solving the basic balance equations, in detail discusses advanced numerical algorithms for the resulting nonlinear and linear prob­lems and completes with a number of benchmarks, applications and exer­cises to illustrate the different types of problems and ways to tackle them successfully (e.g., flow and seepage problems, unsaturated-saturated flow, advective-diffusion transport, saltwater intrusion, geothermal and thermo­haline flow). The book is available for sale online.

 Scope and Structure

This documentation is intended as a practical guide to groundwater modelling with FEFLOW 8.1. It aims at explaining the essential work steps of model setup, simulation and postprocessing, and at presenting alternative options and set­tings with their advantages and disadvantages for specific applications. Thus this manual can serve both as an introduction for FEFLOW ’newbies’,reference for more experienced users and detailed description of the user-interface elements and workflows

The documentation follows a typical modelling workflow—starting from basic maps and finishing with postprocessing and extending FEFLOW’s capabilities. Each chapter starts with an introduction to the topic, presents the relevant FEFLOW tools, describes the concepts and workflows, and ends with a tuto­rial.


The FEFLOW 8.1 documentation has been designed in a manner the user can quickly read the information and then identify its corresponding location in the FEFLOW 8.1 graphical interface. For this purpose, we can place throughout the document a series of small icons to indicate if we refer to a menu, toolbar, context menu, etc. Below you find the list of the different notation used in this documentation.


FEFLOW button. Press in button to carry out certain operation.

FEFLOW context menu. Make a right-click to display the context menu of certain parameter.

Write certain input information, e.g. in Editor toolbar.

FEFLOW menu.

FEFLOW panel.

FEFLOW toolbar.

Display file dialog.

Activate a check box.

Select one of the option only.

Extend a list of options and select one only.

Additional Information

During the documentation we will identify coloured boxes containing additional hints and warnings.


This is an example of a box with additional hints.


This is an example of a box with additional warnings


Example of box with references to the FEFLOW Documentation:


Location of Demonstration Data

Most of the tutorials are based on prepared files, thus they require installation of the FEFLOW demo data package. <FEFLOW demo> in a file path refers to the folder of the demo data installation. The default installation location may differ between operating systems. On Microsoft Windows (versions 7, 8 and 10), the typical installa­tion location is: C:\Users\Public\Documents\DHI FEFLOW 8.1\demo


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