I Am Guessing,

this is a pretty rare occurrence,

the outside layer of the water appears frozen, but liquid still flows, Italian photographer Dario Bonzi captured this remarkable footage in the central Alps valley of Val Camonica of water flowing out of a pipe that appears to be completely frozen, this amazing illusion is caused by streamline (laminar) flow, which means when low velocity liquid flows in parallel layers without lateral mixing or other interruptions, it appears incredibly still, for more about laminar flow and Poiseuille’s law for resistance, have a look here, now that colder weather is here I wonder if we will see a similar occurrence?