How do I derive a river network and catchment from a DEM using QGIS?

I'm using the latest version of QGIS 3.30.3 and in it, the SAGA tool (and consequently, the Fill sinks option) isn't available in the processing toolbox. Is there another way to do this?

I'm new to QGIS so I don't have much idea. it would be great if you could help me with this.


2 Answers 2


As wrote here in the changelog for the QGIS 3.30:

This provider has not been maintained and does not work with newer SAGA versions. Users are encouraged to use the 3rd-party « Processing Saga NextGen » plugin instead.
After many many years of discussion, it’s time for the inbuilt provider to go!

So to use SAGA, you have to install this plugin : "Processing SAGA NextGen"


If you're looking for a Fill Sinks algorithm, WhiteboxTools is a good alternative.

There is a QGIS Plugin called Whitebox for Processing that can be installed to integrate it with QGIS in a similar manner to SAGA.

WhiteboxTools has a range of algorithms, and they are generally operate very quickly (NB: I have no association with WhiteboxTools!).

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