Load-bearing capacity of L-stone and water drainage at 45° slope

Have a maintenance shaft built somewhere on your real pipe (costs a few hundred euros, but it's worth it). If you then let your cistern fill up halfway once or twice a year, you call that sewer maintenance or pipe flushing and that's it.

At least that one is already planned and registered in the building application.


Your legal case described on page 4 partly concerned the soakaway shaft, which caused all the water to have to pass at the feet of the L-shaped bricks.

Let's assume somehow it works with a channel to catch the water flowing above the L-shaped bricks from the south and lead it to the east into the cistern. Then let's also assume I’m allowed to pump the excess water into the sewer.
Where does the water go that has already seeped through the soil from the top of the property (lawn/meadow, driveway, etc.) down to the L-shaped bricks? That is below the channel that fills the cistern. Is this water okay, or is that also a problem?
If that is a problem, then everyone who works with L-shaped bricks has exactly the same problem...

Where does the water go that has already seeped from the top of the property (lawn/meadow, driveway, etc.) through the soil to the L-bricks?

Normally, a drainage is required behind the L-bricks. In the case of in-situ concrete, a few drain pipes are often installed that then lead the water to the lower area. (Would that be the neighboring property in your case?)
Alternatively, the water can of course continue to seep into the subsoil if not too much water is coming in (continuous rain, pipe break).

At least that one is already planned and listed in the building application.


Your legal case described on page 4 referred, among other things, to the infiltration shaft that caused all the water at the feet of the L-shaped stones to have to seep through.

Let's assume somehow it works with a gutter to catch the water flowing above the L-shaped stones coming from the south and lead it east into the cistern. Then let's also assume I am allowed to transport the excess water to the sewer via a pump.
Where does the water go that has already seeped from the top of the property (lawn/meadow, driveway, etc.) through the soil down to the L-shaped stones? That is then below the gutter that fills the cistern. Is this water okay or is that also a problem?
If that is a problem, then everyone who works with L-shaped stones has exactly the same problem...

Well, the L-shaped stones are not simply placed on the slope. Especially at 2m height, with 1m width, we are already talking about 1000kg per stone. If they are further reinforced, surely even more. They must not sink, so they need a foundation. How the construction looks (how much gravel, concrete, etc. in the different layers) is usually specified by the manufacturer or should be correctly calculated by the structural engineer.

Depending on how the foundation looks, it ideally also requires a drainage (in front of the leg of the L-shaped stone). At least I would install that as additional safety. Simply because this area is the most sensitive spot.

Probably one can calculate whether the amount of precipitation + permeability of the slope makes that unnecessary (since everything is intercepted at the surface). But for that you need the statement from the soil report / hydrological evaluation.
And the drainage itself will ideally not increase the costs drastically (sewer connection at the bottom end possible) as it can be planned directly during the installation.

Of course, your problem is that this drainage would be at the lowest point of your property... from where the water would first need to be removed again :(

how did you solve that with your large stones?

What exactly do you mean? We don't have stones but reinforced concrete walls with a large foundation. The walls are sealed so that no water enters the public area. The water infiltrates on the property. We also have an old well/spring on the property. The excess water eventually ends up there. If necessary, we pump it into the cistern.

What exactly do you mean? We have no stones but reinforced concrete walls with a large foundation. The walls are sealed so that no water enters the public area. The water seeps into the ground on the property. We also have an old well/spring on the property. Eventually, the excess water ends up there. If necessary, we pump into the cistern.

Ah, I misunderstood you. I thought you had also installed L-stones on the site.