Position of the water pipe unknown

For each building plot, there is a water and a sewage valve on or at the street, both marked with a water and sewage sign at the respective property boundary. Hence the question of responsibilities. If a valve is installed, there is usually a pipe attached to it - otherwise, the valve would make absolutely no sense and would be completely uselessly installed.

Without a house, it also makes no sense if even the tiniest piece of pipe were to follow the valve.

For every building plot, there is a water and a sewage valve on or at the street, each marked with a water and sewage sign at the respective property boundary. Hence the question of responsibilities. If a valve is installed, there is normally also a pipe connected to it – otherwise, the valve would make absolutely no sense and would have been installed completely pointless.

You know that – or you suspect that?
Plots are also often split. I rather suspect the existing valve was installed for another construction project or maybe, as a precaution during the street renovation, they actually installed a valve for your plot, but laying an “empty” branch line to the property boundary without knowing where the connection is ultimately supposed to go – no, that almost certainly has not been done. That’s probably why there are no documents about it. Save yourself the manhole probing. Just apply for the connection and that’s it. The branch line will be shot anyway; they won’t tear open the whole street for you now.

Of course, I do not know for sure. I assume so, since up to now I have been told from all sides - partly by experts or directly from the sewage and water association, except now from you - that there should be a pipe there, even if there is a valve. And that a valve without a water pipe is extremely unusual or practically a planning error. In addition, for example, the sewage pipe is also adjacent to the property.

But yes, I do not know it 100%.

since I have so far been told from all sides - partly from the experts or directly from the sewage and water association, except now from you - that there should be a pipe there, even if there is a valve. And that a valve without a water pipe is extremely unusual or practically a planning error.

When a road is torn up to renew a pipe, you don’t want to have to do it again soon because an adjacent meadow is sold and now someone wants to build a house on it. So the T-piece for that house connection is installed right away, and the valve is its closure for then, or later its interface for the branch line. Laying the branch line itself right away would then be a planning error. You don’t yet know exactly where the possible future house will stand, and there is no fee-paying user for the branch line yet. So the valve will be in the T-piece in the pipe, the water sign should therefore indicate the location of the pipe, since the valve is on it. The T-piece between the pipe and the valve is kept as short as possible to avoid creating stagnant water at the opening. Stagnant water does not stay fresh well, and the pipe is supposed to be a pipe and not a breeding ground. What kind of intern holiday replacement have you talked to there?

There are just no exact records anymore and the employee from the water association is shifting that onto us, like "Well, just look for it...".

So, I think something is going wrong here. It cannot be that you are required to find water pipes where there might not even be any. If they have no records, that is their problem. Because where else are you supposed to dig around? Digging up other people's properties is not your task, but a governmental one.

Just apply for the connection and that’s that.

I agree.

I agree.

The problem is probably not the house connection for which the supplier first has to find his line again. But that the OP cannot proceed with his building application as long as he cannot complete the drainage planning. I would coldly draw the lines where they are supposed to be according to the sign. What does the layman have to do with the digital backlog of the waterworks draftsmen?