Soil survey on the property revealed high groundwater levels

Good morning,

we had a soil survey carried out before purchasing the plot.
At the drilling points, a groundwater depth of 1.4 to 2.1m was found, and the top layer of about 80cm needs to be replaced.

Question for you:
How much will the replacement approximately cost?
Has anyone built with a high groundwater level and has experience with it?
We are concerned about the possible permanent water pressure against the base slab. Are these concerns justified?

Best regards
dragonfreak

In our area, all houses were therefore built with basements, as otherwise significantly more complex foundations would have been necessary.

In unserem Gebiet wurden deswegen alle Häuser mit Keller gebaut, da ansonsten wesentlich aufwändigere Gründungen notwendig gewesen wären.

But a basement doesn’t really solve the problem either, because the water just presses against the wall, right?

Besides, we didn’t necessarily want one .. especially since then only a [Weiße Wanne] would be possible again.

1.20 m were replaced at our place with a house footprint of 100 m2 + garage 50 m2 with a groundwater level of 2.20 m and the costs for the foundation (MuBo removed, excavation up to 1.20 m, everything disposed of and filled with a capillary-breaking layer) were about €8,000 net.

It does not depend solely on the groundwater level. There were no concerns about the groundwater from any side in our case. I wouldn’t have any either at 1.40 m if you are building without a basement anyway. Or is it otherwise a swampy area where water sometimes reaches the surface during a long rainy period?

Thank you for your response.

The danger is more likely that the water wants to seep away and therefore accumulates on the surface. We would probably have to do something extra for the drainage.

Hmm, okay. Does this already happen on the undeveloped property? Is the soil very clayey? The rainwater has to infiltrate into the ground now as well.

In the future, it will either be drained into the sewage system or on the property. If the latter (as with us), then there are various options. For example, we have to install a pipe-rigole infiltration system. This is basically a long large drainage pipe in the garden, which lies 2 m deep in the ground for us. The rainwater is introduced there and then infiltrates into the soil. There were no concerns from anyone that this wouldn’t work despite the high groundwater.

If your groundwater is at 1.40 m, then the underside of your floor slab will be about 1 m above that. Between the floor slab and the groundwater-bearing layer, there is a capillary-breaking layer that prevents water from "rising" (capillary effect).

To be honest, I don’t quite understand your issue? Have you ever talked to your architect or someone responsible at the municipality/city? Usually, such a groundwater level is nothing unusual.