Is it legally to put a snorkel on a road?

The benefit of installing a snorkel on the road and overcoming water barriers is not questionable. But here the owners of the outroad raise the following questions. How will the inspectors of the road and patrol service react to an outroad with an installed snorkel? Do I need to make a snorkel? Should I put a sign on my technical passport? Does this mean the reinstallation of the vehicle? Should I legalize the snorkeling?