Quarry risk to TranzAlpine train, but no quick fix

11:30 am on 11 May 2024
A view of the abandoned Kiwi Point Quarry, with the rock outcrop dubbed a hazard, right, and the Kiwi Point rail overbridge and State Highway 7, bottom.

A view of the abandoned Kiwi Point Quarry, with the rock outcrop dubbed a hazard, right, and the Kiwi Point rail overbridge and State Highway 7, bottom. Photo: Supplied / West Coast Regional Council

Delays in the decommissioning of dangerous rock quarry near Greymouth have raised the ire of a West Coast regional councillor.

A fresh report on the mothballed Kiwi Point Quarry this week to council's Infrastructure Governance Group did not go down well with councillor Peter Ewen.

West Coast mine historian and regional councillor Peter Ewen.

West Coast mine historian and regional councillor Peter Ewen Photo: Supplied / West Coast Regional Council

Ewen, a recognised West Coast mine historian, said the risk to the public from the site had already been on the radar for at least six years and the fresh report - following a geotechnical report in mid-2022 - made no reference to the abandoned underground mine shafts dating back to the 1920s beneath the site.

The site remains on notice from WorkSafe.

Ewen said the risk of the site's collapse onto the TranzAlpine tourist train route and State Highway 7 had been well signalled - as seen in June 2022 when the train ran into a slip below the quarry access road.

"The risk is there. Furthermore, in 2018 it was highlighted it would affect the state highway and the TranzAlpine. Well, in 2022 the train hit a slip there - under the bridge."

The TranzAlpine hit a slip beneath the Kiwi Point rail overbridge. That incident was relatively minor but, "heaven forbid, we have a large slip and another train or vehicle gets caught", Ewen said.

"I'm pretty disappointed with [the report] actually because historically there has been front page stories on this site.

"There's quite a void there and to not have that included in a report is a deficiency I'm not prepared to accept."

Council ceased operating the quarry about 2020 after 45 years of extraction.

Since then part of the access road has been removed to deal with the slip risk onto the road and railway below.

"I've raised this before … the risk is sub-surface.

"The deficiency of not having that in those official reports is not right. I object to receiving these like this," Ewen said.

He said "a big cavernous shaft" in the area escalated the risk yet council now had two reports which failed to appraise that.

Ewen has repeatedly raised the risk to council staff in public meetings in the past two years.

He said his concerns could be verified by historic mine maps and the issue was well known locally.

A staff report said the latest consultant study recommended "an extensive amount of work which will be costly".

Acting catchments manager Shanti Morgan said another "risk assessment" on the quarry's current status, as well as on the necessary work to make it safe, were recommended.

That would allow for cost estimates to formally decommission the site, Morgan said.

An aerial view of the Kiwi Point Quarry in 2020 when most quarry activities appeared to have ceased. The Kiwi Point rail overbridge, the railway and state highway into Greymouth can be seen between the quarry and the Grey River.

An aerial view of the Kiwi Point Quarry in 2020 when most quarry activities appeared to have ceased. The Kiwi Point rail overbridge, the railway and state highway into Greymouth can be seen between the quarry and the Grey River. Photo: West Coast Regional Council

Council chief executive Darryl Lew said Ewen should be tapped by staff to ensure the consultant was fully informed, pending an expanded report.

Committee chair Frank Dooley said while the latest report was based on scope, "if that scope is deficient that is another issue".

"What councillor Ewen is saying, that is an issue."

Councillor Peter Haddock agreed and said the quarry being above an historic mine was known, as was the risk from a local faultline nearby.

He also said the latest report effectively repeated the previous 2022 report.

Councillor Brett Cummings said the latest report did identify a rock knob above the quarry as something council had to deal with given it was a fall risk.

"Council didn't put it there - that seems unfair. That's going to be the dearest part, removing that natural feature."

LDR is local body journalism co-funded by RNZ and NZ On Air.