Manawatū Gorge shortlist of alternative routes revealed
An alternative to the road through the Manawatū Gorge could take up to seven years to complete.
On Wednesday, the NZ Transport Agency revealed the four frontrunners from the list of 13 possible alternative routes released last month.
The four shortlisted routes are an upgrade to the Saddle Rd, a new road north of the road, a new road south of it and a new road south of the Manawatū Gorge.
All options through the gorge had been ruled out.
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A full tunnel through the gorge could have cost up to $2.2 billion and a viaduct could have cost up to $1.4b.
"No matter what we do in the gorge, it will not be resilient," NZ Transport Agency regional transport systems manager Ross I'Anson said.
The chosen routes are expected to cost between $300 million and $550m to build and will take between five and seven years to complete.
State Highway 3 through the gorge has been closed since April when several slips fell and blocked the road. In July, the highway, the main link between Manawatū and Hawke's Bay, was closed indefinitely after the hillside was deemed too unstable.
The cheapest shortlisted option is the 13.8-kilometre Saddle Rd upgrade, which is expected to cost between $300m and $400m and take between five and six years to complete.
The longest of the four shortlisted options, a 19.2km route south of the gorge, is the most expensive and would take six to seven years to complete at a cost of $450m-550m.
Maps released by the agency showing the alternative routes depict "corridors" about 300 metres wide, I'Anson said. The exact route would then fall somewhere inside that space.
I'Anson said the agency now better understood the complexities and the size of the project.
The new timeframes were conservative, he said.
A top preferred option would be chosen by December.
The agency was monitoring the gorge and if the hillside stopped moving, it would consider opening it again, I'Anson said.
The agency doesn't have a record of how many slips have come down since the gorge closed, but spokesman Andrew Knackstedt said about 27,000 cubic metres of material had fallen since April 24.
About 10,000cum has been taken out of the gorge and about 15,000cum of material is still on the road.
If the Saddle Rd upgrade is the final route chosen, it may be closed off at times, meaning motorists would have to take the Pahiatua Track, south of the gorge.
However, most of the work would take place off the existing road, so it was hoped traffic would not be affected too much if it was chosen, I'Anson said.
A public meeting to discuss the options was held in Palmerston North on Wednesday, while further meetings in Woodville and Ashhurst will be held on Thursday and Friday, respectively.
REACTIONS FAVOUR ONE ROUTE:
Visitor reactions at the public presentation leaned strongly in favour of doing the job right, no matter the cost or time taken, to ensure a road that would meet needs for the long term and be fail-safe.
Of the people spoken to by a Manawatū Standard reporter, almost all favoured the southern-most route, which starts immediately north of Palmerston North.
Palmerston North retiree Joseph McKee said the geology of the land under the northern three routes was soft and prone to landslides that could cause road closures.
He said the new road would need four lanes or regular passing and slow bays, so trucks creeping up the slopes did not slow traffic.
"You've got to do it properly. It's got to last."
Long-time Ashhurst resident Jenny Olsson, who now lives in Palmerston North, favoured one of the routes close to Ashhurst, as the infrastructure could help open up subdivision of rural land. However, she wanted to protect the quiet village character of Ashhurst from traffic.
Retired city councillor David Ireland liked the southern-most option because it diverted the road from Ashhurst, but said Saddle Rd and the Pahiatua Track would need continuous upgrades anyway.