Media Release

The national quarry organisation says it hopes that the delays and cost blow-out for Transmission Gully may finally see a change in Government and council planning for major projects.

Aggregate and Quarry Association Chief Executive Wayne Scott says Transmission Gully is only a signal of what will happen unless the authorities address the need to plan for the quarries to supply major infrastructure initiatives, climate change mitigation, and affordable housing.

“The Government has now asked the Infrastructure Commission to investigate why Transmission Gully’s costs have gone through the roof and time delays mount.

“We’ve been telling this, and previous, Governments that they must put in place planning to provide for quarries. You cannot expect existing quarries with set caps on production to meet the mega-requirements of a project of the scale of Transmission Gully.”

Wayne Scott says both major parties are now promising a huge lift in infrastructure spend as a key policy to address Covid-19’s economic impacts.

“Unless we make the first step of a rapid identification of available rock resource, we will find the delays and cost blow-outs of Transmission Gully will be replicated around the country.”

He says rock for the Wellington motorway project was in such short supply that some was trucked from Huntly.

“You can imagine what a 1,000km round trip added to the cost.”


The AQA has already shown the benefits of identifying local supplies of quarry material with the Ōpōtiki wharf project. The estimated cost blew-out to $150M partly due to having to truck rock nearly 100km. The AQA worked with GNS Science to identify local sources of supply which contributed to a near halving of the wharf project cost.

“While not the total answer, similar gains can be made if we complete a national survey of rock resources which GNS has started but can’t complete for the sake of $600,000 in funding. If the Government is serious about avoiding more Transmission Gully events, that’s where it should start.”


*Since writing this article, the AQA has been advised cartage of material from a Huntly quarry to Transmission Gully did not in fact proceed. It has been acknowledged however that material has been carted from as far away as Mt Taranaki (a return trip of more than 600km.) The AQA regrets referring erroneously to material being transported from Huntly, a 1000km+ round trip though thinks its point stands on the need to plan for local quarries rather than carting aggregate very long and costly distances.