New construction - Neighbor denies access to drinking water

Hello,
I am new here and have a question right away.
My partner and I are currently building a house, and the house is located at the north end of the property with access to the street.
On the opposite side of the street is a pasture, and the Trinkwasseranschluß of the property owner denies us access (no permission to dig).
Is he allowed to do that!
There is a second connection on the south side of the property, but then we would have to have the supply line laid about 50m across the property.

I would objectively ask the water association (water supplier) of your municipality. They know best.

Again: I am only reading now: it is his own drinking water connection. He paid for it, so why should he be able to be "tapped" by you? Where is the main line? I understood that the main line is at his place, and he just does not like it being dug up.

No, it is indeed the main line. He just doesn't want any digging to be done there.

His good right. You will probably have to dig the 50 m or bribe your neighbors.
Is my layman's opinion.

According to the municipality, we had to build on the north side by the street because all new accesses are located there. We would have liked to build on the south half, where there is still an older water access, but we were not allowed to.

As mentioned, the pipeline was newly laid a few years ago. How does it actually behave
a: if he acquired the property before the pipeline construction
b: if he acquired the property after the pipeline construction