“There are many areas which are very vulnerable”: how rising sea levels will change Sydney 

Scientists warn that events such as the 2016 erosion of Collaroy-Narrabeen beaches (pictured) will become more common as sea levels rise. Photo: UNSW Newsroom.

“So many people think, ‘20cm sea level rise? Well that’s nothing,’” says Associate Professor Ana Vila-Concejo, a marine geoscientist from the University of Sydney. “But when you have 20cm and on top of that you put larger storms and on top of that you put a storm surge – then the damage is massive.” 

Few cities have an identity fused so completely with the water as Sydney. Visitors covet Sydney’s beaches, while the cream of its real estate clings to the foreshore. 

But as sea levels rise and climate change brings increased storm activity, these areas are under increasing threat from destructive flooding and beach erosion. 

The recent Intergovernmental Panel on Climate Change report provided a bleak outlook on multiple fronts, including the prospect of the world’s oceans rising by the end of the century between 28cm and 55cm from levels recorded between 1995 and 2014. And that’s taking into account the most ambitious of emissions reductions.

Professor Ana Vila-Concejo, whose research includes the processes and morphodynamics of ocean beaches such as Bondi, Tamarama, Bronte, Coogee and Maroubra – as well as beaches in Botany Bay and Pittwater – says the impending destruction of our coastline needs more attention. 

“Are people thinking about it enough? I don’t think so. There are many areas which are very vulnerable and areas that are already showing erosion – and real estate is still a very expensive asset there.”

Andrew Short, Honorary Professor at the University of Sydney’s School of Geosciences says, “The political will is pretty weak, they tend to side with the most vocal people around. At the state, and definitely at the federal government level, they don’t want to know about the coast.”

Short’s work in his field has included extensive study of Collaroy-Narrabeen beach, an iconic strip of sand notoriously under threat from extreme erosion. 

“Not only will the beach disappear as sea levels rise but, at the moment, whenever you have big seas and beach erosion the sea wall will be exposed, you will not be able to walk along that beach – it’ll be very hazardous to anyone surfing having to confront a sea wall at the shoreline.”

“It will become more and more difficult to insure your property. And you may not be able to pass on your property to your family. You may have to relinquish it to the government.”

– Professor Penelope Allan

Professor Penelope Allan, from Sydney’s University of Technology, sees a concerning lack of will on the larger issue of rising sea levels and, typically, short term political thinking.

“What will happen is that it will become more and more difficult to insure your property,” she says, “And you may not be able to pass on your property to your family. You may have to relinquish it to the government or something like that.

“In the long term, people are going to have to ready themselves for that. People are going to have to find properties that are just as desirable but in other parts of Sydney.”

Shifting sands

Beaches, at least, actually have the natural ability to survive rising sea levels, by retreating inland. But this applies only if they are given the freedom to do so – which is where those of Sydney are typically at a disadvantage. 

“A natural beach responds to sea level rise by moving landwards,” says Professor Vila-Concejo, “So if there’s nothing behind the beach, the dunes will move backwards and the entire system will move backwards. You can see evidence of this in the geological records in many cases. 

“However the beaches in the Sydney Basin have roads and houses at the back, so they cannot do that.

“With sea level rise they’ll become submerged, eroded, the sand will have nowhere else to go and there will be massive, very expensive problems, once the water reaches the sea wall and the properties and the infrastructure.”

Drone footage of severe coastal erosion on the Northern Beaches in 2016. Video: UNSW Water Research Laboratory/YouTube.

Sea walls

The natural movement of dunes to account for sea level changes feeds much of the controversy about the use of sea walls. 

As Professor Short explains, “The problem with the sea wall, it’s a terminal fixture – in other words, nothing can go past it. It means as sea levels rise the beach will retreat and eventually it will get to the sea wall. You’ll end up with a sea wall and no beach.”

Hard truths need to be faced, it’s argued. Professor Allan says, “You can in the short term manage with sand-banking and rock walls etcetera. What they do is they make it worse. Really, the longer term response is just to move.”

Sea walls are an intrinsic part of the management of Collaroy-Narrabeen on the Northern Beaches. 

Perhaps the most infamous recent case of beach erosion, this stretch of sand was subject to a devastating 2016 storm which damaged the beach to the extent properties were left teetering on the brink of the ocean

Short says he believes the continuing sea wall strategy represents an acquiescence to private interests over the public. 

“What they’ve done is sacrificing the beach, the public beach amenity and also public safety. 

“The council and the state government – they’re both involved – have decided to put the protection of private property ahead of public beach amenity on one of Sydney’s most popular beaches.”

The council’s response to these accusations is they are dealing with inherited problems with no easy, or inexpensive, fix. These complications essentially derive from the fact properties were allowed to be built, several decades ago, in potentially risky areas in the first place.

Even the sea walls, the council says, are not a new phenomenon. 

“The decision to protect properties at Collaroy-Narrabeen was effectively made many decades ago with the installation of rock protection works,” says Northern Beaches Mayor Michael Regan. “The strategy council is [currently] employing will reduce the amount of rock on the beach providing more beach space as sea levels rise.”

Northern Beaches Council say they are taking the lead on the issue, working with owners and the state government to find a solution. 

“Council has had to work within a state government framework it doesn’t control to protect our beach, manage the interests of our ratepayers and address the risks facing homeowners fronting the beach.

“Owners are responsible for funding their works, but are being supported by grant funding from state government and council, a first on the NSW coast. Owners need to work with their neighbours, which in some cases requires more than 10 neighbours to agree on a strategy and funding.” 

An artist’s impression of the sea wall protecting property at Collaroy-Narrabeen. Image: Northern Beaches Council.

Castles built on sand

And simply buying out the owners of billions of dollars worth of real estate is unaffordable, not without considerable state or federal government support. 

Professor Short says, “They could have voluntary repurchase of a beach front property – but the council ran out of money and the state government would not contribute any funds, nor would the federal government.

“If they bought back those properties, they demolish them and turn them into public space. It’s expensive but what dollar value would you put on a public beach?”

Otherwise, another option is building out the sand artificially in front of the sea wall. “They could still nourish the beach,” says Short, “But it’s not being considered at the moment.” 

Northern Beaches Council, however, claims beach nourishment will be an important part of their strategy in the future. 

Beach nourishment is already an important tool against beach erosion in multiple locations around the world, including on Queensland’s Gold Coast, where it has been used for decades.

It is also used extensively in the US states of Florida, Hawaii, North Carolina and Virginia, and in the Netherlands (where one-quarter of all land is below sea level), among other places.

The effects of beach nourishment are clear to see at Virginia Beach, USA. Photo: rwilson/Beachapedia.org.

Wave effect

What can be certain is that the conjecture and huge costs associated with rising sea levels and storm surges are going to be pervasive up and down the coast. Planners and politicians are faced with the immediate challenge of design problems decades in the making – ones that require considerable engineering, outlay and, perhaps most elusive of all, forward thinking.

Vila-Concejo believes, “In the councils there are really good people working and thinking about this but they are under-resourced and underfunded to do what needs to be done.” 

And often, of course, there are competing imperatives within councils that want to allow more development.

Even a beach like Maroubra, which is not backed by properties, is going to face problems once waves start to hit the promenade and Surf Club behind the beach. 

Councils at least seem aware of the problem. On the issue of Maroubra Beach, a spokesperson for Randwick City Council told the Sentinel they were, “In the process of preparing an Eastern Beaches Coastal Management Program with Waverley and Woollahra Councils, but beyond that I don’t have many details I can provide you with at this point.”

Meanwhile, Vila-Concejo says harbour and estuary beaches are going to be amongst the hardest hit. 

“These beaches are more vulnerable – they are typically smaller, narrower, lower and they have been brutally developed with no respect to the dunes whatsoever. 

“They might be affected by a particular storm but there’s not enough waves to bring the sediment back. Those beaches are extremely vulnerable and already needing quite a lot of engineering intervention – that’s the case, for example, with Lady Robinson’s in Botany Bay.” 

On this issue, as well as the issue of development at Brighton-Le-Sands and the western shores of Botany Bay, Bayside Council did not respond either to emails or phone calls.

The vulnerability of Brighton-Le-Sands, pictured, on Sydney’s Botany Bay is clear to see – however the local Bayside Council did not respond to queries about plans to deal with rising sea levels. Photo: Novotel Sydney Brighton Beach/Facebook.

Where there’s a political will there’s a way

Unfortunately, funding, or the lack of thereof, is the crux of the problem – for which, as Professor Short has pointed out, the state and federal governments need to do some heavy lifting. 

A statement issued to the Sentinel by Rob Stokes, NSW Minister for Planning and Public Spaces, noted the big challenges of sea-level rise. 

“If we could start from scratch, we certainly wouldn’t allow residential development along parts of our coast.”

– NSW Planing Minister Rob Stokes

“If we could start from scratch, we certainly wouldn’t allow residential development along parts of our coast. We’ve established the coastal management framework and flood-prone land package to make sensitive and sensible decisions about future development in coastal and flood affected areas.”

Unfortunately, they seem to be on their own – the federal government does not appear particularly interested in helping. 

When asked specifically about this issue, a spokesperson for the Hon Sussan Ley MP, the federal Environment Minister, simply told the Sentinel, “States, territories and local governments have responsibility for most on-ground coastal adaptation action.”

The projected impact on downtown Sydney if the sea level was to rise by two metres. Image: Coastal Risk Australia.

Stormy weather

Of course, storm damage and rising sea levels impact more than just those immediately at the beach front.

Projections available on the website Coastal Risk Australia show significant encroachments on land from rising sea levels in the Inner West by 2100, including parts of Alexandria, Marrickville and Haberfield. Perhaps more obviously, areas around Sydney Airport and the Cooks River at Wolli Creek will be significantly impacted without protection.

Professor Allan says, “Obviously anywhere on the coast, anywhere on any river – where it’s flat or low-lying [is at risk of flooding]. That whole Alexandria area, the ground water is very close to the surface.”

And issues such as the submergence of coastal stormwater outlets under rising sea levels, will add to the stress on old infrastructure. 

Time lapse video of a king tide on the Cooks River. As sea levels rise, king tides will become more common, and regular tides will start to resemble king tides. Video: Inner West Council/YouTube.

A postgraduate director in landscape architecture at UTS, Professor Allan has worked on projects incorporating water sensitive urban design, including Victoria Park in Zetland – using landscape such as green space as a natural “buffer” for hazards like flooding. 

She says, “There are solutions but it takes a huge shift in the way the government thinks about the way they develop suburbs in the city. How they do urban development. It feels like they know what to do – but there are so many constraints, political constraints that prevent them from doing it.”

The City of Sydney Council, at least, seem pretty confident they have the situation in hand. Proactively addressing the impact of climate change is a key priority – including improving drainage. Sydney Lord Mayor Clover Moore cites that between 2016 and 2018, they worked with Sydney Water to build a $140 million, 2.4km trunk drain below Green Square – which takes in storm water and directs it to Botany Bay.  

Moore says she calls it, “Our ‘sexy drain’ because although it isn’t as visible or beautiful as the nearby Green Square Library or our new aquatic centre, it has been just as transformational.” 

She also says there will be “mitigation measures, against rising sea levels, into future parks and capital works programs”. Interestingly, however, she says Council’s floodplain management plans have considered sea level changes and found “minimal” impact on flood levels during storm events. 

The City of Sydney, led by Lord Mayor Clover Moore (pictured), is proactively addressing climate change and its effects, including rising sea levels. Photo: Hpeterswald/Wikimedia Commons published under Creative Commons 4.0 licence.

A drowned world

Nevertheless, for many low-lying coastal communities around Australia – including Sydney – climate change is going to force a massive rethink on planning and infrastructure. And, hopefully, a concomitant injection of sorely-needed money. 

“Sea walls, the buy backs, the nourishment, it’s all very expensive, [needing] state and particularly federal government support,” says Professor Short. “And you need a consistent policy that would ideally be applied Australia wide.

“But every state has a different policy – different approaches – there’s a total absence of federal initiative and support, in terms of dealing with the coast and the impacts of climate change.”

As with all other climate change issues, time will tell if there’s any will to take decisive action – and may do so in devastating fashion.

Richie Black is the deputy editor of the Sydney Sentinel.

======================================