Safety concerns are mounting about a massive slip threatening to close the main highway on the West Coast.

The slip at Knights Point on State Highway 6, north of Haast, happened during heavy rain in October 2012.

More than three years on, locals' concerns are mounting over the lack of action by the NZ Transport Agency (NZTA) in stabilising the slip and preventing it from bringing down the road.



NZTA says it is monitoring the slip though and does not believe it poses a threat as it is at least five metres from the road.

SUPPLIED A slip threatening State Highway 6 at Knights Point north of Haast.

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West Coaster Josh James Marcotte expressed his concerns in a video on Facebook.

Marcotte said just four steps off the road was a "a massive slip that goes right down into the ocean."

SUPPLIED NZTA are monitoring a slip at Knights Point, north of Haast, which threatens State Highway 6.

It was "crazy" that NZTA was not doing anything about it, he said.

"All the tourism businesses are going to lose tens of thousands worth of business because no-one will be able to come up and down the Coast. Something has got to be done."

Sheri Wright, of Haast Heliservices, said she had been monitoring the slip from the air since 2012.

"It's definitely getting worse. It has cracks in it. The road is slumping in places. When it goes the road will be closed for months. I can't believe they haven't done anything about it," she said.

She was worried about tourists who camped nearby at a scenic look out.

"What concerns me is whenever I drive there at night there has always been campervans parked up on the layby there. If that thing goes overnight we are going to lose people. It's just crazy," she said.

"The locals know it's getting worse and we drive through there like lunatics to get past it but you see tourists slowing down looking at the amazing view with no idea they are driving on the edge of a precipice."

NZTA regional performance manager Pete Connors said the agency was monitoring the slip with instruments that measured groundwater and ground movement.

"A small amount of movement has been recorded although it is not unexpected given the environment at Knights Point. It presents no danger to road users and safety remains the Transport Agency's prime consideration," he said.

The slip was "largely unchanged" since it happened in 2012 due to erosion.

"As well as these instruments, the site is visually inspected at least weekly, with road users' safety the guiding priority. The road itself is much lower than the ridge separating it from the slip and set back by at least five metres," he said.

The agency planned to look at design options for the section of road in the next year if the instrument readings revealed any cause for concern.

Options included cutting the road further back into the rock face, lowering the highway and building an anchored piled wall.

Three years ago, NZTA estimated the work would take up to three months and cost up to $2 million.