Booth said the the rapids were an ideal setting for the scene because the spillway turned the otherwise dry gorge into a fast-flowing waterfall.
The crew worked with a local river company to safely release and retrieve the barrels.
Tolkien's The Hobbit is set 60 years before the start of the tale told in The Lord of the Rings and is about the adventure of the hobbit Bilbo Baggins, who goes in search of treasure with 13 dwarfs.
The scene shot along the Aratiatia rapids is part of an escape where Bilbo Baggins rescues the dwarfs from elves by hiding them in barrels which float downstream.
The Hobbit: An Unexpected Journey is set to premiere in December and the second film, The Hobbit: There and Back Again, next December.