Hello Sanna,
Like S Bard I am from Belgium, and an expat - I now live in France (Sough Burgundy).
Your account of the dry summers in Belgium amazes me.
We suffered from severe droughts here in Burgundy the last two years but I thought that it was at least a bit better in Belgium!
Catching, storing and using rainwater will be crucial in the future.
I tried a hugelbed but found it disappointing, it is just too dry here - I also had raised beds for a few years but went back to flat beds, easier to manage with very little rain.
Gaby