Drainage, have I thought correctly?

[HarryStem]

Hello

I am new here and thought I would check if I could get some feedback.

I have a summer house located on a sloped lot.
In my attached sketch, I have marked where I get a water accumulation by a wall (dashed line). The entire house is built on rock, and this is the only wall that is even possible to drain. The other sides consist of 5 cm of soil and then directly the rock. Below the rock side, I have a grass plateau, then the house built on a slope, and below again a grass plateau.
At the dashed line is the only place where the wall of the house goes into the ground about 1-1.5m, although the basement is above ground level (not furnished, rock as the floor).
My plan is to try to catch the water on the upper grass plateau and along the rock, and direct it down to the existing drainage well, thereby reducing the water amount on that side of the house.
The reason why I can't lay down drainage pipes by the exposed foundation is that the slope becomes wrong towards the existing drainage well.
Lines from the house are from roof drainage that can be directed without problems towards the existing well. The other lines are the drainage.


Then a question. Since I have nothing below ground (i.e., no buried basement), does it matter if it is bone dry or not at the bottom of the foundation of the house at this place? I don't perceive the wall in the basement as particularly damp inside. From the lowest point of the foundation in the ground to the sill is probably 3m.

So what do you experts think about this setup?
Or is it perhaps completely unnecessary?

 

[mexitegel]

It is not good for the cellar wall if it is constantly damp as you risk frost damage. It doesn't matter if it is wet three meters down.

You are right to try to divert as much water as possible before it reaches the house. Can't you just raise the ground by the house so that it slopes away from the house?

 

[HarryStem]

It's not good for the foundation wall if it's constantly damp as you risk frost damage. The fact that it's wet three meters down doesn't matter.

You're right to try to divert as much water away before it reaches the house. Can't you just raise the ground by the house so it slopes away from it?

Hey, thanks for your response.
Unfortunately, I can't raise the ground level there.
The last sketch is kind of an exploded view, showing how the bedrock looks under the soil. Outside the wall, the ground is as high as the basement door.

But as you said, the plan is to catch as much water as possible before it gets there.
Dug down to the bedrock at that wall now. It was maybe 120cm down and it's a pool of water right now. Crazy. However, the drainage guys saw again today that practically everything comes from the upper plateau at one spot. The bedrock continues all the way under the ground past the house in principle, so I hope my plan is enough.

Does anyone else have some input?