I have posted this picture before, back in 2005, but it is well worth reposting. He is called Rain Man and sits in the lake in St Kilda Botanic Gardens or Blessington Street Gardens, if you like. The pump is solar powered and I would assume it does not work if it is overcast.
It was a bright sunny day when I was there, so the water was flowing full stream.
Bear in mind, this photo is over three years old, so who knows what the present status of Rain Man in our water starved land. Anyone know if he is still there and working?