- "It was like rushing down an endless, slimy, dark slide. He could see more pipes branching off in all directions, but none as large as theirs, which twisted and turned, sloping steeply downward, and he knew that he was falling deeper below the school than even the dungeons."
Plumbing is a system of pipes and fixtures put in a building to distribute water for drinking, heating and washing, and drainage of waterbourne wastes.
In one of the rare instances of wizards copying Muggle practices, wizards started to adapt to plumbing systems in around the 18th century. Up to that time, wizards chose to relieve themselves wherever they stood, and then proceeding to Vanish the evidence.
Most of Hogwarts Castle's elaborate plumbing system dates back to the 1700s. When plumbing works started, the secret entrance to the Chamber of Secrets — which was, at the time, comprised of a concealed trapdoor and a series of magical tunnels — was threatened, as it was located in the site of a proposed bathroom. However, a student at the school at the time, Corvinus Gaunt (a member of the House of Gaunt) a direct descendent of Salazar Slytherin, and a Parselmouth), managed to secretly protect the trapdoor and to conceal it behind a newly-installed sink, so that those who knew how could still access the entrance to the Chamber.
- Harry Potter and the Chamber of Secrets (First appearance)
- Harry Potter and the Chamber of Secrets (film)
- Harry Potter and the Chamber of Secrets (video game)
- Harry Potter and the Goblet of Fire (video game)