Rainwater must be obligatorily infiltrated

I also bought such a thing at the big river. Unfortunately, the hose installed internally was so thin that the flow rate was ridiculous. Yes, it would have been enough for hand washing, but not as construction water (which it was needed for).

Wow, I didn’t expect so many answers in such a short time!
In order :)

When I google Rigole, it looks like a box that you bury and then let water flow in here with pipes. Currently, we have drawn normal downpipes that then end in a control shaft.
How about a Rigole? Instead of directing the water into the control shaft, simply direct it to the Rigole?
How does that even work? Can you see it from above?

Is that the same as a Rigole?
The water prices really make you think more and more about the additional costs of a cistern. As I said, we actually left it out, but somehow it increasingly seems to make more sense than, for example, a carport :-/.

Can you let the water run out openly directly from the downpipe with that?

Is it really that simple? How do you get the water from the roof in there? If it seeps away more slowly than it can drain, doesn’t it back up the downpipe again?

We don’t yet know what kind of soil it is (we were always told that you make a soil report only when the building application is approved). The neighbors say it’s rather clayey. The property was an orchard meadow where nothing has ever been built, so a green meadow since forever.
What is a “sickerschschtringe”? And what kind of pipe do you knock in? Sorry.

plus approx. 35 meters of cables from the driveway to the soakaway = another 3.5k)

You’re not seriously paying 3,500 for 35 meters of pipe, are you? :D