Hangstützmauer = Building permit or distance?

Unfortunately, we have 2 meters of natural terrain that need to be retained. 1 meter is not enough. So far, there is no support at all there, which is why the slope debris constantly falls onto the street. And next to it, cars are parked...

As I said, I would ask the building authority – after all, it is also about traffic safety when the junk constantly ends up on the street – that can have relatively unpleasant consequences for two-wheeler riders (especially in the dark)...

No, for cyclists it's not dangerous, and pedestrians don't walk there either. There is no sidewalk, only a 40 cm wide curb, and right next to it the cars are parked. All the pedestrians walk on the street here. But I don't think it's at all unlikely that a head-sized chunk could crash onto a car. After all, the little fence is still there, but eventually all the stuff that has accumulated behind it will have enough weight and the little fence will give way.