Tourist mecca fighting to turn tide on Mother Nature

The wildly popular Queensland holiday destination faces a years-long recovery as its city council splashes millions on the battle to return sand sucked out to sea along its world-renowned 42km stretch of paradise after ex-Tropical Cyclone Alfred.

One of the most significant weather events the Gold Coast has faced in 50 years, Alfred gouged six million cubic metres of sand from the shore when it lashed the city in March.

The recovery could drag on for three years, Mayor Tom Tate says. Northern beaches will reopen before then but dune restoration "could take some time".

Council is also considering rock walls and groynes to lessen erosion.

The cost and detail on how works will be funded shift with the sand.

The council has budgeted $24 million for beach nourishment works this financial year, including offshore dredging and the Surfers Sand Backpass Campaign, an underground pipeline that pumps sand from The Spit south to Surfers.

It's expected a significant portion will come from the Beach and Environmental Recovery Program as part of Commonwealth-state disaster recovery arrangements, according to the council.

Bond University Associate Professor Daryl McPhee says returning beaches to "normal" by 2028 defies logic.

"It assumes no serious erosion events happen between now and then," he tells AAP.

"Choosing a static point in a dynamic system is destined to fail. Ongoing works would be expected to run into the hundreds of millions.

"Nature always wins."

Bond University coastal erosion researcher Mark Ellis says the forces reshaping shorelines are becoming more extreme, more frequent, and more difficult to manage.

"Are they pushing the proverbial uphill? I would say yes," he says of efforts to mitigate erosion.

He questions whether council should keep shelling out for post-disaster beach reconstruction and building sea walls and groynes that could contribute to further erosion.

"At the end of the day, vertical sea walls protect property; they don't protect beaches and they won't be able to hold back the sea," he says.

Assoc Prof McPhee says the solution to fixing erosion is ensuring beaches and dunes retain biophysical function. 

"This requires considering such systems as dynamic and ensuring that remaining dunes are protected and, where possible, revegetated," he says.

It's easy to see why council wants to protect its golden shores.

The city estimates they generate $1.3 billion annually for the local and state economy and support 50,000 full-time jobs.

They've also helped drive continuing migration throughout Australia, with the Coast's population of at least 700,000 forecast to swell to a million by 2040.

"Sand coming and going from Gold Coast beaches is a natural process," Assoc Prof McPhee says.

"However that process is hindered by many of the coastal developments that make up the Glitter Strip. 

"There is an irony that so many people come to the Gold Coast for the beaches but much of the infrastructure needed to support that visitation reduces the resilience of the beaches to disturbance and slows their recovery."

He says a sea wall such as the "A-line", which is largely buried, is an appropriate structure to protect properties and has served the Gold Coast well - so far.

But he cautions against expanding the Oceanway, which "impacts dunes and reduces the resilience of the beaches and reduces their ability to recover".

Rock groynes could impact surfing amenity and impede the northward movement of sand - and enhance erosion in certain places.

"Sand pumping is a very expensive band-aid with significant local environmental impacts and potential unassessed impacts on local Indigenous culture," he adds.

The recent natural events have dramatically affected man-made ones, too.

Cr Tate has been trying to open the city's shoreline for major events and commercial operations, including a controversial proposal for beach bars, since he was elected in 2012.

But those plans, like many of the city's 24 beaches, copped a battering from Alfred, with several signature set-in-sand events cancelled or postponed and others forced to relocate.

Council reportedly spent $30 million in four months on sand pumping to unsuccessfully repair eroded beaches in time for Easter school holidays and a money-spinning air show, with high tides and big swells hampering operations.

It's a problem environmental experts warn, unlike sand, is here to stay.

"Council is very aware of climate modelling and it is expected more events will be disrupted," Assoc Prof McPhee says. 

"We need to rethink large-scale events on Gold Coast beaches and recognise they are fragile natural environments."

Mr Ellis says dunes can't do their job when vegetation is damaged by foot traffic, by events such as the air show or SeaFire or by poorly placed infrastructure.

"Without room for dunes to migrate and rebuild, the beach itself is squeezed out of existence."

Unlike many coastal enclaves that have protected their foreshores as public open space, the Gold Coast has built to the waterline.

But with the Surfers Paradise sea wall "constantly getting exposed" and council continuing to spend millions renourishing beaches, Mr Ellis says it's time to re-think the "hold-the-line" approach

"How long is it before the next storm surge happens and the oceanfront properties with their underground car parks are inundated?

"In other high-risk beaches, such as Wamberal Beach in NSW, where numerous houses have been impacted by erosion, I would say the point of no return has been reached yet the planning system still allows houses rebuilt on the dunes. 

"Look at the erosion issues at Stockton Beach, Byron Bay in NSW, Victoria, South Australia and Western Australia."

Mr Ellis, who has been researching options for managed relocation of communities at risk of coastal erosion, says there is "no political will" to stop waterfront developments or pursue managed retreat strategies as discussed in the Gold Coast council's Coastal Adaptation Plan. 

"Yet, the impacts on legacy development - homes built in erosion-prone zones - continue to face increasing exposure now, not in 20 or 50 years' time," he says.

He says government must invest in long-term, adaptive coastal management strategies, not just reactive fixes.

"That means thoughtful dune restoration, strategic retreat in high-risk zones and limiting damaging activity on fragile beachfronts."

Assoc Prof McPhee says the recent Gold Coast erosion should be considered Mother Nature's "warning shot".

"We still have great beaches - and the Gold Coast is not being depopulated because there is less sand on the beach," he says.

But most previous serious erosion events occurred when there was substantially less large-scale coastal development. 

"The Gold Coast cannot be 'unbuilt' but there does need to be better consideration of the impacts of severe erosion on individual developments and the cumulative impacts," he says. 

"At some stage there will be catastrophic property loss but it sadly probably requires that loss to occur and the associated insurance issues to drive real change in thinking."

Australian Associated Press