Filming for Peter Jackson's latest movie The Hobbit took to the Aratiatia rapids near Taupo for a scene using spill gates from a dam.
Publicist Melissa Booth said the film crew dropped 20 to 25 barrels down the rapids at a time yesterday for the scene.
"We shot the scene every time there was a dam release which was at 10, 12, 2 and 4."
She said no actors or stunt crew were forced into the barrels to venture into the extreme conditions.
"I think we would have had some issues with OSH if that were the case."
The scene was the only part of The Hobbit to be filmed in the area.
Mrs Booth said the rapids were an ideal setting for the scene because the spillway turned the otherwise dry gorge into a fast flowing waterfall.
The crew was working with a local river company to safely release and retrieve the barrels.
Tolkien's The Hobbit takes place 60 years before the start of the tale told in The Lord of the Rings.
The story 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 rapids, about 10km north of Taupo, are operated by Mighty River Power.
The Hobbit: An Unexpected Journey is set to premiere in December and the second film, The Hobbit: There and Back Again, next December.