There was a brief article in our local paper the other day about Olafur Eliasson’s Waterfalls. These are four man-made waterfalls built on New York’s East River. They pour down from great heights (between 90 and 120 feet) and are up to 80 feet across. All the water they use is pumped up from the River itself, a kind of permanent recycling. (Though I don’t think there are any water purifiers involved!)
You can read a full article on the waterfalls in the New York Times, which includes a video about the falls, with their creator speaking, and lots of moving pictures of them.