Who has to support the property?

Hello and good evening community,
I am reaching out to you because we are currently considering a matter.
First of all, I would prefer not to start a neighborhood dispute in advance. I just want to clarify who has which "rights."

At the beginning of the year, we purchased a plot of land on which we will now build.

My neighbor and I both own a corner plot because we are essentially located on the inside of a new development area. There is basically a street running around us. (like a U)

However, we are also dealing with height differences in the street. On my side of the street, I am 40cm lower than the neighbor.

My neighbor has adjusted the top edge of his plot to his street level, and we want to adjust the top edge of our plot to our street level as well.

Both property owners had the same top edge of the plot (fill during new development) at the beginning of the construction work.

Now it is so that my neighbor has backfilled. (See picture)

My simple question is, who has to retain their plot in this case? Does he have to prevent soil and water from overflowing onto our property, or do I have to do it now because we are building after him?

Thank you very much in advance

Regards, David

Good evening,

what is written in the pdf of the attachment applies ... actually in every federal state.

Source pdf: Kreis-Stormarn.de/lvw/forms/5/53/Die_Gel_ndeoberfl_che_im_Bauordnungsrecht.doc

Rhenish greetings

Ok, I only understand gibberish there
Do I now have to find out the natural ground surface?

Attention layperson's opinion...

Of course, as a rule, the street level... Thus, in my eyes, your neighbor has done nothing wrong... he is free to cut back beforehand or to intercept at the boundary...

Of course, as a rule, the street level...

No. The existing terrain is the natural ground profile; the street level "can" be the reference point, provided the valid development plan indicates this.

Thus, in my eyes, your neighbor did nothing wrong... he is free to cut back beforehand or catch it at the boundary...

Yes ... just not "or"

In plain language, this means that every landowner is responsible for their property and must ensure - loosely speaking, that not a crumb of soil from their property ends up on the neighbor's land.

Rhenish greetings

Typical case, but fairly clearly regulated. If the neighbor wants to cut back the slope, he can do so, but he must do it entirely on his own property, including any encumbrances/setback areas (yes, local embankments can trigger setback areas/encumbrances!). Depending on whether he is acting within or outside the regulations of the development plan, different scenarios arise.

BUT: it does no harm to come to a pragmatic agreement, because the original ground level is "lost" after a certain time, i.e., the new property surface edge then applies as the future planning height for further projects, even if it is obviously not a natural ground surface.

So if neighbors agree and find a solution so that no one has water standing in the basement/living room, then that should be aimed for. In this case, these are not extreme slopes, but as far as I can judge from here, within about a meter. For example, he could cut back his slope and you cut back yours. For this, you need - if taken to the extreme - at least mutual consent, because you, for example, are not allowed to simply cut back the slope on your property at the boundary without the neighbor's consent, even if it makes structural sense. Ideally, you meet in the middle.

If the neighbor insists on a level property surface edge, he should just install L-walls. That is then 100% his problem and not exactly the cheapest solution.

Kind regards Dirk Grafe