"It will be the frontline of defence": Rebuilding the great wall of the Gold Coast

Josh Adsett

7 News has been given an exclusive behind-the-scenes look at the massive construction project to cyclone-proof a vulnerable Gold Coast beach.

The original Narrow Neck seawall was built from timber and could be destroyed by powerful seas.

Metres below the high-tide mark, big machines are clawing at the sand.

Construction on the sand: building the Gold Coast great wall. Photo: 7 News

The excavators are pulling out boulders and randomly scattered rocks from a buried line of defence against the sea.

The original Narrow Neck seawall was built in 1959.

Many of the old timbers have fallen apart so a 900-metre stretch is being unearthed and rebuilt.

The original Narrow Neck seawall was built in 1959. Photo: 7 News

"It will be the frontline of defence so that it will protect life and public property," Gold Coast Mayor Tom Tate said.

The new wall has small rocks as a base and much bigger ones on top.

"Armoured rock wall, so this is to make sure that that final line is as strong as it possibly can be," infrastructure planner Alton Twine said.

Many of the old timbers from the 1959 build have fallen apart. Photo: 7 News

The $6m build should be finished by the end of the year.

It was delayed last month when an excavated section had to be filled in again quickly as ex-Tropical Cyclone Winston passed by.

"We saw the track of that ex-tropical cyclone coming straight into the Gold Coast and we thought ‘ok, we are taking this final line of defence out, we are actually going to temporarily put some of it back’," Mr Twine said.

Special attention is being paid to the Narrow Neck seawall project.

There is only 30 metres of land between the rocks and the Nerang river and if the wall does not hold up in a cyclone, this area could be cut in two.

It has happened before.

"In 1894, when there was about 20 cyclones or similar type systems affected the waters off here, and that was when South Stradbroke Island broke in half," Severe Weather Meteorologist Jeff Callaghan said.

The Gold Coast has felt the full force of the elements in the past - and is likely to in the future. Photo: 7 News

There have been many severe weather events on the coast since then but they have been nothing like those of the 19th century, experts say.

The coast is due more: "An active period over the next 15 years or so, it will be interesting," Mr Callaghan said.