qgis-malstroem is a QGIS plugin which adds a number of hydrology algorithms based on malstroem to the QGIS Processing toolbox.

This is a fork of the original qgis-malstroem repository. It seems like the original malstroem repo is not maintained anymore. This repo is intended to be a maintained version of malstroem.

First install malstroem. It can be installed into any python interpreter on your system. Specifically, you don't have to install it into the python interpreter used by QGIS.

A correctly installed malstroem provides a CLI executable. To configure qgis-malstroem correctly you will need the path to this executable.

If you haven't installed QGIS. Now is a good time to do so :-)

Install qgis-malstroem by copying the folder malstroem to your QGIS plugins folder. On Windows this folder is usually located at C:\Users\{username}\.qgis2\python\plugins on other systems usually at ~/.qgis2/python/plugins.

After a QGIS restart the plugin should be available in the Plugins dialog (Plugins -> Manage and Install Plugins). You may have to check the box next the plugin to activate the plugin.

Now open the Processing Options dialog (Processing -> Options). Now, under Providers you should see a Malstroem entry (if not, check that all the above steps have been carried out). Make sure Activate is checked. In Malstroem script you put the path to the malstroem executable (i.e. C:\Python27\scripts\malstroem.exe).