"Waterfalls" also ushers in deeper questions about the role of public art in urban life. Apart from the inevitable flood of media attention, how do we judge whether a public project has been successful? The ultimate test, experts say, may be a work's ability to forge connections – by reaching out to its viewers and engaging them in their environment.
Historically, public art has forced "you to reconsider your relationship to that site. It shocks you out of your complacency," says Noah Chasin, assistant professor of Art History at Bard College in Annandale-on-Hudson, N.Y.
Rochelle Steiner, director of New York's Public Art Fund, a major backer of "Waterfalls," hopes Eliasson's project has precisely that effect: "People will think about the city, the East River, and nature – particularly water as a natural resource – differently after having seen them."
Eliasson likes to tweak perceptions on a large scale. His best-known work, a 2004 installation at London's Tate Modern titled "The Weather Project," toyed with the illusory power of artificial light. Ms. Steiner, who is also the curator of "Waterfalls," describes it as "an insertion of 'nature' into the urban conditions of the city."
For a city, of course, success is often gauged in more tangible terms: Public-art projects can generate an incredible amount of community revenue.
In 2005, for instance, the European artists Christo and Jeanne-Claude erected more than 7,500 saffron-colored nylon banners across Central Park for two weeks. According to Kate Levin, commissioner at New York's Department of Cultural Affairs, "The Gates" generated approximately $254 million.