There would not be much growing on the right side of the Rhône River without these irrigation ditches. And certainly the famous white wines, such as Fendant of the Valais would not be around!
In French they are called 'bisses' and in German 'suonen'. The locals built them with their bare hands, wearing leather boots that might have had 3 nails in them, often hanging off sheer cliff walls to dig a passage for the water from the glaciers to the fields that needed the precious meltwater drops.
As you can see they pass through hot and dry spots. The vegetation is really fun to walk through.