Mizunuki (water drain-down) 水抜き(mizunuki)

In cold regions — Hokkaido, Tohoku, the Japan Alps and highland areas — many houses have drain valves (水抜き栓) to empty the pipes when the house is left in winter. A burst pipe in an empty house can run for weeks unnoticed, so draining down before freezing weather is one of the most important winter tasks.