How to install

First download and install the current stable release of Julia. Please see platform specific instructions for further installation instructions and if you have trouble installing Julia.

If you are new to Julia, it may be a good idea to check out the Getting Started section of the Julia Manual. Links to other learning resources can be found at

Wflow can be used in two different ways, depending on the required use of the code:

  • If you want to stay up-to-date with the latest version, explore and modify the model code, and write your own Julia scripts around the wflow package, we recommend installing wflow as a Julia package.
  • If you don't need extra features, but just want to run simulations, a complied executable version is available. This consists of a single executable, wflow_cli, allowing you to run the model via the command line.

Below we describe how to install both versions of wflow.

Installing as Julia package

Wflow is a Julia package, that can be installed through several different ways. Below we show how to install wflow from Julia's package repository, and how to install the latest version from GitHub.

Install from Julia's package repository

To access Julia's package manager, press ] in the Julia REPL. To get back to the Julia REPL, press backspace or ^C.


If you have not used Julia in a while, it can be a good idea to run up to update your packages.

pkg> up

Access Julia's package manager and install wflow using:

pkg> add Wflow

This can take a while, especially the first time, since compatible dependencies are also automatically looked up and installed from the Pkg General registry.

Install from GitHub

It is also possible to install wflow from the master branch as follows:

pkg> add Wflow#master

This command will track the master branch, and will update to the latest commit on that branch when you run update, or simply up, in the Pkg REPL. The use of add will install wflow in you home directory under .julia/packages/Wflow. Note that packages installed under packages by add are supposed to never be altered in that location, for Pkg and it's automatic dependency handling to work well.

If you want to make any changes to any of the files in the repository, you need to do a development install. This can be done using:

pkg> dev Wflow

This will clone the git repository, put it under your home directory in .julia/dev/Wflow, and add the wflow package to your project environment. Note that to receive updates, you have to pull in the latest changes yourself using git pull.

Check installation of wflow

Finally, go back to the Julia REPL and try to load wflow:

julia> using Wflow

The first time this will take longer as any package that is new or changed needs to be pre-compiled first, to allow faster loading on subsequent uses. No error messages should appear, indicating that you have now successfully installed wflow.

Before ending this section, we want to recommend a few tools that can make using and developing Julia code easier.


There is a section on editors and IDEs for Julia on, scroll down to see it. We use and recommend Microsoft's free and open source Visual Studio Code. When combined with the Julia extension it provides a powerful and interactive development experience.


When planning to make changes to the code of wflow, we recommend installing the Revise.jl package. This package allows you to modify code and use the changes without restarting Julia. Install it with add Revise from the Pkg REPL. Then create a file called .julia/config/startup.jl, and put using Revise there. This will load Revise every time you start a Julia session.

Installing the compiled executable

Binaries of wflow_cli can be downloaded from our website, and are currently available for Windows. Download and install the .msi file. After installing you can see two folders in the installation directory. It is only the bin/wflow_cli that is used. The artifacts folder contains binary dependencies such as netCDF.


Check whether the installation was performed successfully by running wflow_cli with no arguments in the command line. This will give the following message:

Usage: wflow_cli 'path/to/config.toml'

The old version of wflow, based on Python and PCRaster libraries is also available to download from our website We recommend installing the Julia version, as this documentation is written to support this version.