Water gavel, also known as water hammer, refers to the loud knocking sound produced in a plumbing system when water flow is abruptly halted. This phenomenon occurs due to the sudden change in water momentum, causing pressure surges and vibrations. Various synonyms can be used to describe this phenomenon, including hydraulic shock, fluid shock, or water thump. Additionally, it can be referred to as banging pipes or plumbing knocking. Regardless of the term used, water gavel occurs when valves are closed too quickly, causing water to collide with pipes, resulting in a distinct noise that can be bothersome and potentially damaging to the plumbing system.