In 1974, the Lafayette waterworks in Louisiana revealed an apparent correlation between drops in water pressure and television viewing habits. In particular, the water pressure would drop immediately after popular shows and movies had aired… presumably from viewers waiting until the end of the shows to relieve themselves:
So, the idea was floated that flush ratings might serve as a surrogate for the Nielsen ratings.
I had always thought that the idea of popular TV shows having an impact on sewage systems was an urban legend. However, while Snopes dismisses the idea that any shows such as the Superbowl have ever broken a city’s sewage system, they allow the lesser claim that massive simultaneous flushing can put an observable strain on a city’s waterworks, noting: “toilet use during breaks in large-audience programs can certainly be much higher than average.”
Related post: Flush Polling