Does the street sink after development? Who is responsible?

I might also report it to the community or consult with them. After all, it is "their" street. Maybe you can get backup from there.

Maybe you can get some backup from there.

Or just an invoice right away ;). First involve the "perpetrator", I would bring the municipality on board later.

Or directly an invoice ;). First include the "causer", I would involve the municipality later.

I would do it the other way around and report the subsidence to the municipality in writing (burden of proof) and also immediately specify who did the work. Someone from the municipality will look at it and, if necessary, call the utility company via a short official channel.
If you do nothing now, it could cause trouble later on. However, the legal situation is a bit special here. A company was commissioned that specifically had the authorization to open the street. So, as the owner of the neighboring property, you initially have nothing to do with it.

If it is a construction road, it doesn't matter anyway, as a completely new road will be built in 1-2 years.

It was probably compacted incorrectly. The municipality will likely approach you and demand a repair, so you should clarify this directly with your contractor.

In our case, after the development of the new residential area, the roads around the shafts subsided after 6 months. The entire road is now being completely renovated by the municipality. The reason was rumored to be a mistake by the geologist.

Why should the municipality approach him? He commissioned the municipality and not the civil engineer.

Incorrect compaction... Excavations of this kind will always lead to settlements, as compaction cannot be done over the whole area. Normally, the asphalt is laid slightly raised, but only the base layer, and after some time and the expected settlements, the final state is established.

I would report it to the municipality including the photos, and normally they will then respond.

if it is a construction road, it doesn’t matter anyway, since a completely new road will be built in 1-2 years.

The road is like the residential area from 2008... we bought the last free plot in 2014... unfortunately also the only one that didn’t have the pipes laid up to the boundary. Due to the unfavorable construction site, they probably thought back then that nobody would build there anyway... so no pipes were laid in the first place... but we then got an exception for the construction site because it was the last plot / special case, etc...

The city already thanked us back then for having to open the 7-year-old road again for the development. :confused:

Hello, what a coincidence. I am currently facing the same issue, but our street used to be a "Wasserdecke" and is now just a mud track because the area of the excavation (from the property boundary to the middle of the street) is settling and the gravel/stones have been driven out. I informed the municipality yesterday, but they explained to me that it is initially my responsibility to inform the civil engineering company. I will try to do that today...