It is a spectacular sight: tens of millions of litres of water exploding from the spill gates of Aratiatia Dam, leaping and gushing through the narrow gorge below.

It is a sight that draws thousands of tourists to the rapids, above Taupo's Huka Falls, every year.

But for four days this year, those visitors will be turned away - and the tourism operators couldn't be more happy about it.

Peter Jackson has settled on the Aratiatia Rapids as a location for filming one of the dramatic outdoor scenes in his two-part feature production of The Hobbit.

It is only one of the beautiful locations set to feature in the movies, and with every new location disclosed, local tourism operators will be rubbing their hands.

Tourism is worth an estimated $9.5 billion a year to the New Zealand economy, and the pulling power of Middle Earth has been valued at a significant share of that. On top of that is the $500 million that the movie producers are expected to spend during filming and post-production.

Unlike the Lord of the Rings trilogy, much of The Hobbit will be filmed at Wellington's Stone Street Studio - meaning the benefits to the select number of scenic outdoor locations could be even more lucrative.

Hobbit producers have confirmed their return to the Waikato to the Hobbiton set on a Matamata farm.

With Environment Waikato's consent, they have begun diverting up to 890cu m of water a day from a nearby lake and stream to irrigate the lush green Middle Earth set and offset the browning effects of a hot New Zealand summer.

They are also in talks with Ngati Tuwharetoa to film on the central North Island volcanic plateau, though the iwi is not expected to let them feature mountains Tongariro, Ngauruhoe and Ruapehu in the movies.

The movie's location scouts have been busy in Ruapehu, Taranaki and Queenstown Lakes.

Wanaka would seem a perfect candidate for Laketown, the town devastated by the wrath of Smaug till the dragon was brought down by the black arrow of Bard the Bowman.

Mt Taranaki could be the Lonely Mountain, given that Ngati Tuwharetoa is refusing to allow the use of Mt Ngauruhoe.

Farther north, the Department of Conservation revealed to the Herald on Sunday that it granted a four-day "concession" for Weta to film in the Aratiatia scenic reserve above Huka Falls last month.

That filming was delayed by Jackson's hospitalisation for a perforated stomach ulcer, but a new application could be lodged in the coming months.

While production company 3foot7 Ltd isn't saying what role the Aratiatia Rapids will play in The Hobbit, it is possible they could feature as the Forest River, down which Bilbo and his dwarf friends float in (and on) wine barrels to escape the elves of Mirkwood.

At tourism agency Destination Great Lake Taupo, general manager Scott Pearson says the Lord of the Rings has left a "massive legacy" of tourism revenue. "This will enhance the whole Aratiatia experience and we'll see a lot more international visitors."

Jane Kingston, marketing director for Huka Lodge, says the scenery around the Falls is like leaving the real world behind - so is perfect as Middle Earth. "This filming will draw attention to the beauty of New Zealand, increasing tourism and revenue."