Port Augusta Wharf repair to cost $11 million

WHARF: Several of the Port Augusta Wharf's piles have experienced severe marine growth and section loss at the seabed. PHOTO: Magryn Consulting.
WHARF: Several of the Port Augusta Wharf's piles have experienced severe marine growth and section loss at the seabed. PHOTO: Magryn Consulting.

An assessment of the Port Augusta Wharf has delivered a bitter pill to swallow, with the estimated cost to repair the 149-year-old structure priced at $11 million.

Mining, Civil, Structural and Coastal Engineer Terry Magryn from Magryn Consulting revealed the price during his presentation to the Port Augusta City Council on Tuesday night.

With the Wharf in critical condition, Mr Magryn detailed the steps involved in completing a full repair.

"To undertake the repair, we would need to remove the existing decking, remove the joists, remove the bearers, remove the headstocks, pull the piles out, put new piles in, then put the whole thing back together," he said.

"The components that are too far gone will be replaced and we would need to repair the stone retaining wall behind it."

The assessment revealed 70 per cent of the piles had "no life left" and would need to be replaced or completely repaired, while 100 per cent of the bracing had experienced severe rotting and splitting.

The state of the stone retaining wall behind the wharf has been described as "horrific", with a significant loss of mortar and stones dislodged.

"That wall is not remotely safe and areas of the wall have collapsed," Mr Magryn said.

"The Wharf is relying on the stone wall to provide it with stability, but I think it’s actually the other way around. The stone wall is getting stability from the Wharf."

Mr Magryn recommended that pedestrian access to the Wharf remains restricted, while also preventing small boats from going underneath the critically-damaged areas.

"Not only don’t we want people going on the Wharf in some areas, we also don't want them underneath the Wharf," he said.

"Install signage along the Wharf because trip hazards are present. A normal trip hazard is 10 millimetres. We’ve got planks sticking up, spikes sticking up and gaps between planks that are 40 to 50mm."

A complete repair of the structure would involve replacing the existing piles with new timber or steel piles.

Another option would be to repair the existing piles using a jacket system, which includes wrapping sleeves around the pile and pumping them with grout. 

However, Mr Magryn said this system is about the same cost as a full repair and does not have the same visual appearance.

With the assessment now complete, Magryn Consulting will identify – with Council's direction – the most suitable methods for repair and replacement of the Wharf.

The Heritage-listed Wharf, established in 1870, is about 350 metres long and was originally used to import produce, highlighting Port Augusta’s history and early economic significance.