Hydrant sign on the wooden fence

Hello people, I hope I'm posting here correctly and you can help me. Today I had to realize with dismay that the water association drilled a hydrant sign into my fence! Very annoying, drilling into my wooden fence without asking. Not to mention the painting. Is this procedure even allowed? Couldn't they have hung the sign on the next lamppost?

I have read that they are allowed to do that and that you have to tolerate it.

I read that they are allowed to do that or that you have to tolerate it.

The sign was taken down again by the water association after a friendly but firm phone call and attached a few meters further on the street lamp.

The nice foreman also apologized for his colleagues. The sign should not have been screwed to the fence without asking!PROPERTY DAMAGE!

Anyway, everything is back to normal now.