The restrooms in the office building where I work have sinks with automatic faucets, triggered by some sort of sensor, probably motion detectors. I walked in this afternoon and noticed one sink was completely full, with a skin of soap bubbles on top. From past experience, I had my suspicions about what had happened, so I tried to look through a clear spot to the base of the sink.
Sure enough, someone had plugged the sink with a paper towel, then walked away.
That’s inconsiderate enough in any public restroom. But when the sink is automatic, there’s another problem: Once the water reaches high enough, it trips the sensor, and it can get into a feedback loop. As near as I can tell, it filled up the sink until it hit the overflow drain, and eventually the sensor stopped registering movement and shut off.
I rolled up my sleeve, reached in there, and pulled the soggy paper towel out. It started draining, and I started washing my hands in another sink. As I watched, the movement of the water triggered the faucet, and it started running, though fortunately the drain was faster. By the time I was finished, it was clear. Problem solved, though it had already wasted a whole sinkful of water (or more — I have no idea who long it was running before it shut off).
So please, if you must plug a restroom sink with a paper towel, especially if it’s automatic, take two seconds to remove the paper towel before you leave.