Haast Pass bridge plan shelved
After three years of investigations, plans to build a replacement bridge on the Haast Pass will not go ahead.
New Zealand Transport Agency (NZTA) announced today the proposed bridge at the Gates of Haast would not guarantee route security along the Haast Pass section of State Highway 6.
NZTA highway manager Colin Knaggs said a new bridge could not be engineered to withstand a major landslide or other significant event in the area.
"Landslides, slips and washouts are a reality along State Highway 6 because of the nature of the terrain," Knaggs said.
NZTA had spent almost three years designing options for a new bridge. The best option was a cable-stayed bridge with an estimated cost of $35 million.
After completion of the bridge design, concerns were raised about ongoing risks associated with the new bridge.
Knaggs said the high cost and low benefits made it "extremely difficult to justify construction funding".
Even if the new bridge was built, there was no guarantee it would not be damaged if the Haast landslide was activated.
The Haast landslide is located to the north of the Gates of Haast bridge and last activated in the late 1970s.
Heavy rainfall in September caused a slip on SH6 at Diana Falls and traffic is still limited during the day with the road closed overnight.
Work is expected to begin early next month to clear the slip for a full reopening of the road by mid-year.