Instead of creating the usual steel turnstile, the Watergate's designers used the primordial liquid as a psychological barrier. Their logic: People won't like to get their clothes wet. Obviously, they don't live in NY summer and they wear pants.
Or in other words: If they install this on the NYC subway, I would not spend a single cent on my Metrocard. It's a good idea, because most people will actually respect it. Another good thing: If something happens, people can run to the exit without having to go through gates:
Water is only a psychological barrier. Fleeing, panicking persons can escape through the gate without being hindered by any rigid media.
Clever.
An added advantage is that people in wheelchairs or carrying luggage can easily pass through them. Very clever. I hope they get popular. [Yanko Design via Dvice]