Flowing taps

I ‘woke up’ to the sound of running water and left my bed to investigate.

In the bathroom, the cold water tap on the sink was running at full force and the sink was rapidly filling up.

I quickly turned off the tap and removed the plug and the water began to drain away. I turned around, ready to go back to bed but then I heard the tap on the sink filling up again.

For some reason, I thought that this was being caused by water pressure, so turned on the shower which stopped the tap, but then I needed to find a wrench to stop the shower.