Water association unannounced on property

Good day,
I have a question regarding building regulations...

On our property, there is a drinking water pipe in the eastern part, running from north to south. At a distance of 2.50 meters to the left and right, no construction is allowed in this area. We have a registered easement stating that the pipe lies there.

Our drinking water notice was supplemented at the time with the following addition:

"Access to the main supply lines must be ensured at all times. In the event of emergency repairs/pipe bursts, the pipe routes must also be accessible with construction vehicles (excavators)!"

This morning, apparently, two workers wearing safety vests and carrying a strange handheld device (something with two spheres) were on our property. Also at our neighbor’s across the street (whose property is also affected by the pipe). My wife noticed it because she is on parental leave. The men did not ring the bell or anything... simply entered the property and walked around...

I suspect they were employees of the water association. Since they were also at our neighbor’s (they didn’t ring the bell there either – she was home as well). My wife saw them but did not dare to go outside...

My question now: Are they allowed, due to the registered easement, to enter my property anytime day or night without notice?

Are they now allowed, due to the registered easement, to simply enter my property day and night without notice?

Only in an emergency. But even then, they must ring the doorbell beforehand. If planned work is necessary, an appointment should be made. In practice, it is probably similar to surveying work. If it turns out during a survey that I have to enter someone else's property, I also ring the doorbell without an appointment. If then no one answers, I am out of luck, even though the Surveying and Cadastral Act basically grants me the right of access.

I would call the water association and ask if employees from there were involved. If that is the case, I would complain about the behavior and demand that it be ceased in the future. However, they might also have been surveyors.

If it is an "emergency," I can still understand it... but even then, someone could have rung the doorbell beforehand and given a short notice... at least that's what my "decency" would have told me...


An extension to the first question...

Example:
Water association has to enter the property, don't inform beforehand and the gate is closed... then I get into trouble because:

The accessibility to the main supply lines was not ensured at all times...?

How can I even manage that? Leave the gate open all the time? Or can I also give them a key? Has anyone here experienced something similar?

If you lock yourself in, yes, then they would have to have the keys. That's how it is. You might be away, and then....?

You have probably already mentioned the correct term. They are allowed to do that without announcement, but common decency requires a certain social behavior, which unfortunately can no longer be found everywhere.