‘We are custodians’: the fights to save Australia’s eroding beaches

·8-min read

‘Snaking conveyer belts of sand’ are easily disrupted by human activities. Fixing them is no easy task

Graham Slade says Point Lonsdale front beach was a site of many firsts: he was four years old when he first walked on to it, seven years old when he was given his first surfboard and a teenager when he took his first steps into adulthood on its sand.

“As you go through life, everything happened at Lonsdale first,” Slade says. “You went out to a lot of parties in your late teens, getting towards 20 years old, and sampled a few things.

“My main addiction though was surfing, and I’m still pretty keen.”

Looking back, the 69-year-old says that as the surfboards he rode went from cork to traditional longboards to modern fibreglass, he has watched the sand at Point Lonsdale wither.

Over the years, as the swell has grown more powerful, the sand has washed away, leaving jagged rocks after storms.

Related: World's beaches disappearing due to climate crisis – study

Now Slade is among residents who say authorities have a responsibility to rebuild beaches like Point Lonsdale, which have degraded after decades of mismanagement.

“An analogy would be if a driver’s vehicle unintentionally strikes a parked car,” Slade says. “That driver is legally and morally responsible to pay for repairs to that car. It should be the same for the beach.

“The damage was unintentional when they put the sea wall in. They thought they were doing good but didn’t know it would cause erosion. But it has.”

‘It’s already been interfered with’

What happened to Point Lonsdale is in many ways emblematic of what has happened to many other beaches around the country in that its degradation was the product of industrialisation, urbanisation and bad decisions made with the best intentions.

It began nearly a century ago when local authorities built a seawall to protect buildings that had risen atop the dunes. Soon it quickly became clear the wall was causing the sand to be washed away and wooden groynes – long structures running perpendicular to the shore – were installed to hold the beach in place.

They lasted until 1989 when they had worn away and were removed but not quickly replaced.

Over the next nine years the sand on Point Lonsdale began to thin, a process that sped up in 2008 after a $969m project to deepen the Port Phillip Heads shipping channel to allow access for larger container ships.

That work ripped out the natural reefs that provided Point Lonsdale beach some protection against the full weight of the ocean, causing the swell to grow more powerful and throwing it directly up the beach.

James Cotton, from Save Point Lonsdale Front Beach, says residents have tried to work with the Department of Environment, Land, Water and Planning over the last six years to develop a solution but, at the last minute, the department balked.

“All of a sudden they just decided they would just close their work on the matter,” Cotton says. “After a six-year consultation process they came back by email and said really sorry, there’s been a change in policy, we can no longer support any works in this area, case closed.”

The abrupt about-face followed the introduction of the marine and coastal policy in 2020, which attempted a break from the past by preferring hands-off solutions to coastal management – rather than direct intervention.

A spokesperson said the department was now seeking to work with natural processes and would consider re-nourishment programs “in the future”.

“Any intervention in coastal environments can lead to negative impacts elsewhere,” it said. “We work with expert coastal engineers before choosing options to tackle erosion so we can avoid moving the problem elsewhere or causing more damage in the future.”

But Cotton says while this is a good policy for untouched and healthy beaches, Point Lonsdale has “already been interfered with”, which created an obligation for authorities to address it.

“The only reason we’re in this state is because first they put a sea wall in and then they blew up the reef,” Cotton says. “The environment’s already been altered but now they’re saying they can’t do anything about it for fear of altering the environment.”

‘They were a mountain once’

If the situation at Point Lonsdale shows how a beach can be lost – and the tensions created when people try to fix it – actually rebuilding it can be complicated.

Ruth Reef, an associate professor with Monash University’s school of earth, atmosphere and environment, says beaches are fragile places, forever remaking themselves in response to subtle changes in the environment.

With most sandy beaches in the world only having formed in the last 5,000 years as the oceans stabilised and the current sea level settled to a constant, no two are alike and all are precious.

“They were a mountain once,” Reef says. “Think about the beach as a snaking conveyor belt of sand. It’s always exchanging sand. The conveyor belt connects between the land and the deep ocean.

“A beach requires two things. First, a supply of sand, and second, waves gentle enough to keep it from being washed away.”

Those natural beaches that ring 34,000km of Australian coastline largely owe their existence to erosion.

Some began where rivers rose, as rain wore down mountains and the currents carried the sediment to the coast, softening it along the way. Others formed from material pulled by the wind from exposed cliff faces, which was carried up the coast until the sand could travel no further. A further group formed when waves broke down coral reefs or shell matter into fine, soft sand.

If the relative geological youth and the delicate balance of forces needed to sustain a beach makes them special places, restoring them means either finding a way to soften the waves, or feeding fresh sand into the system – often at great cost.

A good example is the hundreds of millions the South Australian government has spent each year to maintain Adelaide’s metropolitan beaches since 1971, when it was forced to intervene.

Before this a chain of sea walls had been constructed along the coast, and infrastructure like jetties and boat harbours blocked the flow of sand along the coast.

Adelaide is not the only city in the world to run similar programs. Tractors and bulldozers trundle out on to Venice’s Lido to repair the sands every spring, while Nice’s famous pebble beach was, at one point, being replenished every day.

Even in Queensland authorities are in the process of building a 7.8km pipeline in the Gold Coast to recycle sand on its northern beaches.

Henley beach in Adelaide
Henley beach in Adelaide. Sand at many of the city’s beaches has needed to be regularly replenished since the 1970s. Photograph: David Mariuz/AAP

You break it, you bought it

Without these sorts of re-nourishment programs, coastal engineer James Guy, who manages the South Australian government’s beach regeneration project, says there would simply be no beach.

“Once you develop along the coastline, you are committing to management forever unless you a prepared to not have beaches,” Guy says. “We locked up sand beneath development and the reality is once we did that – and this is before coastal processes were understood – it may well have unknowingly committed society to managing a strip of beaches.”

In other words: you break it, you bought it.

The success of the program can be seen by work at South Australia’s West beach, which sits roughly in the middle of a beach system that stretches from the cliffs at the south of the Fleurieu Peninsula all the way north through to Outer Harbour.

What exactly eroded West beach’s sand is hotly debated. The state government and environmental groups point to a long history of environmental mismanagement that killed the seagrass that held together sand bars and blocked the natural flow of sand northward along the coast – a process known as longshore drift.

But John Dundon, from Save West Beach Sand, says the previous Labor government “deliberately sacrificed” the beach when it killed a plan to build a pipeline to recycle sand through the entire system due to costs.

“West beach was cheap sand,” Dundon says. “They systematically mined and eroded it to feed beaches farther north.”

Whatever the exact reason, a storm in 2016 hit West beach and cut 10 metres into the dunes, wiping away sand that did not return. A report by Danish Hydraulics Institute in 2017 found the government had underestimated the rate of erosion at West beach by a staggering amount.

Today 500,000 cubic metres of sand will be trucked in from a quarry at Mount Compass to rebuild West Beach. Meanwhile, the South Australian government is looking to complete the pipeline to stop the sand vanishing once more.

Though the work has proven controversial over concerns about the dunes, and there is more work to be done to redirect stormwater runoff, Dundon says it’s been a “joy” to see the beach return after a long fight by the community.

“Humans destroyed West beach – they took away a beautiful coastal oasis and starved it and made it into nothing more than a rocky outcrop, with no beach for surf, and no place for the community,” Dundon says.

“This goes back to the heart of the thing. We are custodians. We need to take care of the environment and foster it for future generations.”

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