Function of a drainage / Who owns the water?

Brief update: The neighbor, his architect (and planner of the outdoor facilities), my wife and I had an on-site meeting over the weekend to find a solution. We excavated a bit and saw that the construction on our side was equipped with a perfect concrete flow bed. The neighbor will partially break this up, remove or undermine an L-stone, and completely redirect the drainage outflow to his property. We did not need to delve into the issue of the Baulastenverzeichnis for now; I am saving that for later in case the discussed solution does not work.

To be honest, I don’t understand the situation on site based on the photos.:

Up to the L-blocks is all your property? On the left a higher part of your garden, on the right your (OSB board) garage, behind that the house + garage (terracotta colored) of the neighbor? His property level is approximately at the level of the lower part of your property, or the higher? I thought he had dug himself in? The seepage water comes from the higher part of your property and flows more or less along the L-blocks, up to your garage - drainage outlet, etc.?

What somehow also causes me comprehension problems:

Background: my neighbor placed L-blocks (backwards) directly on the boundary and carried out an excavation. Behind that lies a drainage in a gravel bed on my property.

“Backwards on the boundary” would mean that more or less everything is on your side? So strictly speaking, the L-blocks and the drainage are yours. Whether you built it, the neighbor, or the Pope is irrelevant as long as the structure now stands on your property. Your garage also connects seamlessly to the L-blocks.

Reminds me of the refugee crisis: one country after another closed the borders, causing a backlog towards the south; in the end, the Greeks were the losers and negotiated the dirty Turkey deal via the EU. You would now have to protect yourself against the seepage water from above, then the future neighbor of the new development would have a lake in his garden. Then he’d do the same in return, etc.

Your current neighbor is actually off the hook and his willingness to cooperate is well meant.

Honestly, based on the photos I don’t understand the situation on site.:

Up to the L-blocks is all your property? On the left a higher part of your garden, on the right your (OSB board) garage, at the back the house + garage (terracotta colored) of the neighbor? His property level is roughly at the level of the lower part of your property, or the higher? I thought he had dug in? The seepage water comes from the higher part of your property and flows more or less along the L-blocks, up to your garage – drainage outlet etc.?

What somehow also causes me comprehension problems:



“On the boundary the wrong way around” would mean that more or less everything is on your side? So strictly speaking those are your L-blocks and your drainage. Whether you built it, the neighbor or the Pope is irrelevant, as long as the structure is now on your side. Your garage also adjoins the L-blocks seamlessly.

Reminds me of the refugee crisis: One country after another closed the borders, resulting in a backlog to the south, the Greeks ended up the losers and negotiated the dirty Turkey deal via the EU. You would now have to protect yourself against the seepage water upwards, then the future neighbor of the new development area has the lake in the garden. Then he in turn does it etc.

Your current neighbor is actually off the hook and his willingness to cooperate is well intended.

No. L-blocks including base are on his land. Drainage with flow bottom built by him on my land. The drainage collects and leads away wild water from the area above both our properties. The lowest point where the surface water collects is roughly the boundary point of both our properties, looking at the terracotta-colored house on the left side.

The drainage + concrete base was constructed without our consent. My garage does not adjoin seamlessly, the offset in depth is just not visible.