Rock ready in Waiotahe

NOT ANY OLD ROCK: John Galbraith (left) and Phillip Claydon stand with rocks the perfect size to create the harbour walls. Photo Troy Baker D9893-37

THE redevelopment of an old quarry at Waiotahe has been a game-changer for the Opotiki harbour development.

Neither one could have happened without the other.

The need for locally sourced rock to supply the harbour construction has seen Waiotahi Contractors redevelop its Osbourne’s Quarry in Gabriels Gully Road, saving several jobs in the process.

And the harbour project could not have got off the ground without the nearly $8 million in transport savings achieved by buying rock locally, making this a mutually beneficial relationship for both.

Waiotahi Contractors director Phillip Claydon said it was special to be extracting rock for the harbour construction mere kilometres from where the family-owned company started more than 60 years ago.

“This is a real game-changer for the region, and we are really proud to be involved in this landmark project with Opotiki District Council on our home ground,” he said.

“We worked really hard to find a solution that fits the criteria and keeps costs down and this quarry does it. Together we can make it work.”

Mr Claydon said the type of rock needed for the harbour construction and the Whakatohea Mussel Factory was hard to come by in the region, particularly now that there was closer management of river gravel extraction.

However, the rock is available at Osborne’s Quarry, located just 20 kilometres from the harbour construction site – more than halving the transportation distance and associated costs from the next closest quarry.

Redeveloping the quarry has allowed the company to save several jobs affected by the downturn in river gravel extraction and Mr Claydon expects several more jobs to be created as projects funded by the Provincial Growth Fund continue.

Mr Claydon expects the quarry will supply up to 300,000 tonnes of rock for the project.

“These projects came up at exactly the right time for us; we were able to save jobs and redeploy people. I expect there will be more jobs created as we move forward.

“This is a game changer for the region and we’re really proud to be involved. The harbour will open Opotiki to industry and will do amazing things for the community.”

Opotiki harbour transformation manager John Galbraith said the Opotiki council was pleased to be working on this special project with a long-lived local company.

“They were a key factor in getting this project off the ground,” he said.

Mr Galbraith said the project needed good quality rock because it would be subjected to an “aggressive wave climate”, possible liquefaction during an earthquake and climate change.

“These rocks will be taking a pounding for the next 100 years and we can’t just use any old rock,” he said.

“We need good quality rock with no fractures, fissures or seams which can swell with water.”

Mr Claydon said a similar example of the conditions the Opotiki Harbour would need to survive in would be the Chatham Islands Pitt Island wharf. During a series of storms at the Chatham Islands waves picked up rocks weighing several tonnes and threw them on to the wharf.

To combat this, the harbour rock will be covered with concrete Hanbar Armour Units.

Hanbar units are three-pronged, “BrikaBlock” type looking units made of high-density concrete.

Mr Galbraith said it would be his hope that these were manufactured on site, the biggest of which would weigh 15.6 tonnes.

In total, the harbour construction would need 256,200 tonnes of rock for the core of the walls, 198,000 tonnes of armour rock and 34,000 tonnes of other rock.

Mr Galbraith has been working on the project for over five years and said it was incredibly exciting to see action happening.

However, he said it was even more exciting for those who had been working towards the project for more than 20 years.

“This harbour will realise several long-held dreams of the Opotiki community, including that of Whakatohea to develop their mussels.”