Life on the Edge: Adapting Coastal Management in a Changing Climate
Dr Hannah Power
Dr Michael Kinsela
Dr Thomas Murray
Dr Andrew Pomeroy
Back-to-back severe storms battered the coast over months and months. The dunes eroded and the beaches were stripped bare of sand. There was barely enough space to lay a towel on the sand - if you could even make your way down the cliff at the end of the access path. Seawalls and walkways along the coast were damaged by the blows of powerful waves, bits of steel reinforcement and pipes stuck out here and there. Many of the beachfront houses were crumbling into the ocean too, their occupants forced out; rubble and pollution littered the beach from end to end. We stopped going to the beach.
It was too dangerous to walk the dog and it was no longer a place of enjoyment. Then came the rain. The storms idled over the coast, unleashing deluge after deluge. There was nowhere for the water to go but over the levees and across the valley plains. The flood levels were unprecedented. Houses on high stilts were submerged, entire communities evacuated. And when they returned, the clean up!
Watching the chaos unfold around us we thought we were lucky with our lot down by the lagoon. Sure, we couldn’t get insurance for flooding either, but we were sheltered from the large waves and river torrents. But we were starting to notice that the water was coming higher each year, on those really high tides and during some of the storms. The lawn died last year when it was flooded with saltwater for days and we had to move the veggie gardens. But we were alright for now, and besides, there were too many properties like ours around the lagoon for the government not to fix the problem before it got too bad. Right?
Sadly, this vision is not one of the year 2150 or even 2100. This is today’s reality for many Australian coastal communities. It illustrates the growing and compounding threats faced by the many Australians who live perched on the edge of the continent.
♦ In 2015, we saw water levels rise in Lake Macquarie and overflow onto the streets of the surrounding suburbs, turning them into knee-deep waterways.
♦ In 2016, we saw infamous images of a pool from a beachfront yard lying on Collaroy Beach following dramatic storm erosion.
♦ In 2018, we saw the residents from 18 beachfront homes evacuated from Wamberal as their foundations hung above an eroding beach.
♦ And early in 2022, record rainfall coupled with storm surges left coastal communities of northern New South Wales submerged for days.
And that is the story from just New South Wales. Elsewhere, permanent changes to coastal environments have exposed previously sheltered settlements to coastal hazards for the first time, such as Bribie Island in southeast Queensland, which became so thin in 2022 that storm waves split the island into two. Events like these are occurring with increasing frequency and impacts as climate change and sea level rise increase coastal hazards and development advances in coastal settings.
So how did we get to this point?
Early development of many coastal settlements began over a century ago. Dirt tracks leading to small beachside shacks were constructed on lots arranged along sand dunes or around the shores of estuaries. As populations grew and the nation fell in love with the coastal lifestyle, these shacks were replaced with houses that multiplied and grew bigger as the decades passed.
Regions that were once isolated coastal settlements became villages and, in some cases, towns or metropolitan suburbs. At the same time, many of these towns and suburbs were found to lie within the reach of coastal hazards such as erosion and inundation. Ocean hazards were usually seen as challenges to be managed rather than avoided. And the sporadic nature of storm events and impacts meant that once a problem at hand was resolved, little was often done to prepare for larger events and impacts in the future.
From its origins, therefore, coastal management has typically been piecemeal, reactionary, and remedial. In contrast, our improved conceptual and scientific understanding, engineering techniques, and predictive capabilities mean that we are increasingly able to effectively model, plan, mitigate, and prepare for coastal hazards. Yet even so, in the absence of rigorous, transparent and actionable approaches to risk-based planning, a tendency to underestimate and underappreciate the potential impacts of coastal hazards has prevailed in many jurisdictions.
Despite a nationwide love for the coast, our coast is neither managed nor recognised at the national level. There is no national legal framework to define the coastal zone, nor is there a national coastal management agency to lead discussions and coordinate adaptation efforts around the country.
Most of the Australian coast is managed at the local and/or state government levels with the capacity, capability, and enthusiasm for coastal management varying between jurisdictions. In many instances, the management of beach and estuary systems is split between multiple jurisdictions and government agencies, which may have conflicting priorities and coastal management objectives.
Adaptation is typically absent until problems arise, with the issues of the moment bandaged with quick solutions that fit into our budgetary and government cycles.
Current policies and practices facilitate communities’ desires to stay in precarious locations in perpetuity despite the obvious risks and potentially prohibitive costs of adaptation. The mounting costs of mitigation and future adaptation demand coordinated approaches that are flexible to prepare for and respond to the exceedance of hazard thresholds.
The timescales over which hazards impact our coasts are also much longer than those of the administrative processes of coastal management. For example, extremely damaging impacts from severe coastal storms may only occur in a given location once every several years or over a decade apart with calmer phases in between.
These extreme events have a relatively low likelihood of occurring each year; such as a 1-in-50 or 1-in-70 chance of occurring in any year (i.e., what scientists refer to as an annual recurrence interval). And for creeping hazards, such as shoreline recession and inundation due to sea-level rise, the timescales of advance extend over many decades to centuries.
These timescales, however, are drastically different to those of the traditional levers used to manage coasts. Budgets are made on timescales of 1-3 years, governments are elected and changed every 3-4 years, homes are bought and sold every 10 or so years, and community infrastructure is designed to last for 10, 20, or maybe 30 years. These timeframes are therefore shorter than the time scales over which we need to understand and plan for coastal hazards.
We face psychological challenges as well. The coast is a naturally dynamic environment that morphs and moves over time; more changes and movement occur the longer we observe the coast. But often the position and shape of the coast are thought of as being stationary and static. We have a general view of the coast being like that of a childhood memory.
Indeed, often there is a metaphorical line in the sand where on one side sits the ocean and on the other is immoveable land on which we can live, build, and sustain a lifestyle.
On one side of the line, you can buy land that is yours to use and develop until you sell it, with property boundaries remaining fixed regardless of any change to the landscape or movement of the coastline. But these embedded administrative constructs are incompatible with the reality of changing coasts as the effects of climate change are increasingly realised.
Optimising our use of dynamic coastal environments in a changing climate means reimagining our approaches to coastal management and planning to embed within them strategies that are adaptive. This is no trivial task, as the development and effective implementation of adaptive coastal management in practice requires a policy evolution to overcome inherited barriers (legal, administrative, psychological), which must be supported by a legal framework that enables and enforces outcomes that address the decisions reached through participatory approaches.
With suitable policy and legal settings in place, however, adaptation pathways facilitated by hazard threshold monitoring and action trigger points can be developed to maximise the social, environmental, and economic benefits from the coastal zone amidst ongoing uncertainty in future societal and environmental change.
So what might an adaptive and sustainable approach to coastal management in a world with a rapidly changing climate look like?
Any idealised picture of the future begins with an open and collaborative discussion of the challenges of living in the dynamic coastal environment with diverse coastal communities. We know that with climate change, the coastal zone is only going to be more affected by rising sea levels, increased flood risks, and increased frequencies and intensities of storm events that will lead to erosion and inundation.
And all of this will be imposed on communities with increased population densities and increasingly complex infrastructure. Communities, local governments, regional policy makers, and technical experts (e.g., scientists, engineers, economists) need to engage in open and honest dialogue to develop and agree on proactive and adaptive coastal management pathways to ensure that our coastal lifestyles can continue to thrive. Ultimately, this will require both top-down and bottom-up approaches to coastal management, as well as clear communication on what actions will be required.
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First and foremost, a national legal framework needs to be enacted to navigate the challenges of continued growth of coastal communities and the increasing pressures of climate change. While reactive responses to natural disasters are often resourced federally, future cost-saving mitigation actions continue to be largely the remit of state authorities.
Further, a federal coastal resilience and adaptation office could support state and local governments across Australia through: developing and promoting best practices in adaptive coastal management; provision of national-scale coastal monitoring data, analysis, and tools; national coordination of goal-setting, decision-making, evaluation, and enforcement in coastal management and planning; and, increased funding for proactive mitigation and planning measures to reduce future coastal risk.
Steps Toward Future-Proofing our Coastal Communities
The pressures of both population growth and climate change are only going to increase. It is therefore critical that each community and region has an agreed upon adaptation pathway that addresses the coastal setting, community values, natural environment, available resources, and regional land-use planning.
These tailored adaptation pathways need to be developed with mechanisms for adaptive decision making that recognise local community values as well as balance social, economic, and environmental factors with an obligation to maximise mutual benefits.
A national legal framework would encourage and support the development of these plans.
Adaptation to living in the dynamic coastal zone has traditionally been thought of as five separate approaches, which can be consolidated into an adaptation pathway:
♦ Avoid, where risks are reduced by not placing infrastructure in a hazard zone;
♦ Nature-based solutions, where hazards are minimised through natural protection, management, restoration, and/or creation of ecosystems;
♦ Accommodate, where occasional hazard incursions are tolerated, for example, by raising a house on stilts or allowing a ground floor to flood with minimal impacts;
♦ Protect, where structures are added to the coastal zone to protect existing and/or new infrastructure from coastal hazards;
♦ Retreat, where infrastructure and/or communities are relocated from a region of high risk to a region of lower risk.
Yet not all of these options are possible or even able to be considered due to the absence of data, the coastal setting, agreed planning strategies, and/or legal mechanisms to activate these adaptation approaches.
As a starting point, co-ordinated and well-funded research across all three levels of government, with data and knowledge openly shared, is required to inform policy development and decision-making in Australia.
This data collection and dissemination program needs to address decision making at the ‘coastal adaptation crisis’ timescale. It will need to address immediate (1-2 year) issues but also facilitate the development of plans for the next 20-30 years and beyond.
Funding for coastal management, monitoring, and adaptation on the order of financial years and political cycles will simply not be adequate to address the longer term (decades to inter-generational) timescales of adaptation. Hence, implementing top-down approaches to address these issues will provide a national framework that values and protects both the coastal environment and coastal living for current and future generations.
Breakout Box: Adaptive pathways mapping
The Adaptive Pathways approach recognises that, over medium to long timeframes, policies and decisions may eventually fail to meet coastal management objectives and thus need to be adjusted or replaced. The approach involves a network of interlinked pathways which set out: how to meet objectives, the conditions where each pathway will result in a failed outcome, and the associated decision points.
When a trigger point is reached (such as when a sea-level rise threshold is exceeded or if the frequency of a hazard event surpasses an acceptable threshold), additional or different actions may be implemented in order to continue on the planned pathway, or an alternative may need to be considered which may ultimately result in a change in pathway.
Through this approach, an adaptive plan that includes a mix of short-term actions and long-term options can be developed that can result in more targeted interventions and expenditure and a more strategic and considered approach to managing the coast.
The image above provides an example of an adaptation pathway showing the historic management pathway and three future coastal management option pathways with two thresholds for adaptation and transfer points that delineate changes from one adaptation pathway to another. The image also shows an alternative pathway that reduces future risk by planning to avoid hazard exposure
Bottom-up approaches would seek to ensure that implementation of a national framework with consistency across key aspects, including the data that supports that framework, recognises local values and embeds objectives to provide tailored solutions fitting for individual communities.
Critical to this aspect, will be increased engagement with local communities with the goal to have communities participate in the establishment of a vision for their coast. Based on research and ongoing conversations, well-defined locally-specific trigger levels and timelines can be identified to develop adaptive pathways tailored to individual communities and regions. These will also help to reduce the increasing exposure associated with uninsurable properties and infrastructure or unaffordable insurance.
There will also need to be an acceptance that standardised approaches will not apply or work in all settings and that solutions will have to be site and region specific, both in terms of the environment and community expectations.
© Image courtesy of the authors
Ask The Hard Questions
We must recognise that when the pressures of climate change become too great, living in some coastal environments may not be viable without substantial intervention. The simple solution (at least conceptually) would be to consider managed coastal retreat, which would involve the buy-back of land and the relocation of communities and infrastructure further inland and to higher elevations.
The concept of managed retreat, however, is both politically and publicly controversial. But managed retreat does not have to always involve the actual relocation of assets; it can also centre around a conservation of what is essential and a re-thinking of how we utilise and co-exist in these high-risk areas without the displacement of communities.
This is the stage where town planners, architects, scientists, and engineers can come together with the community to redesign what living in this dynamic zone looks like. While retreat may not be a palatable outcome for all communities, the conversation needs to be had about the risks of staying put, and whether connection to place outweighs the potential impacts and losses associated with the ever-increasing risks along the coastal strip.
Ultimately, in considering this divisive question, it must be kept front of mind that we are already paying for the costs of past planning decisions and delayed mitigation and adaptation through rising insurance premiums and taxpayer funded natural disaster recovery schemes that are inflated by a rapid increase in uninsurable tenancies.
As has been evident in recent times, the cost of limited or absent resilience and adaptation to natural hazards falls largely on the taxpayer, who may not even be directly affected. Levies, insurance premium increases, loan programs, government buy-back schemes, disaster relief funds, and land taxes are all floated as pathways to fund future natural disaster recovery efforts, but none are without their social and political consequences.
© Image courtesy of the authors
Furthermore, the gross cost of repeated recovery is widely appreciated to greatly exceed the upfront investment in adaptation. In a world of climate change, where communities are dealing with growing and compounding threats along our coastlines, addressing these issues now will ensure we are prepared and have a planned future path to enable our coastal communities to continue to thrive for decades to come.
♦ The creation of a Federal Coastal Resilience and Adaptation Office. This office would be empowered to develop, promote, coordinate and fund best practices in adaptive coastal management to support state and local governments. It would also facilitate collaborative coastal management across the professional community (government, academia, consulting/industry) who each have important skills and capability that will be required.
♦ The creation of a National Coastal Adaptation Legal Framework. This legal framework would ensure the development of nationally compatible coastal adaptation programs that are tailored to individual communities with provisions to facilitate managed retreat. It would also require engagement with coastal communities and stakeholders throughout the coastal management process and facilitate their involvement and ownership of locally specific issues.
♦ The creation of a National Coastal Observatory and Associated Funding. This observatory would support and coordinate a national level approach to coastal science and adaptation research. It would have responsibility for the creation of a data repository and remain its custodian, initially compiling and making available the many coastal datasets that have been collected around Australia. It would also coordinate and fund new national-scale coastal monitoring and research efforts towards the most critical coastal research priorities as identified by the coastal research community.
Dr Hannah Power is an Associate Professor of Coastal and Marine Science at the University of Newcastle and a Science and Technology Australia 2021-2022 Superstar of STEM (www.hannah-power.com). Hannah has worked on coastlines in Australia and around the world investigating the beaches, estuaries, rivers, and reefs and examines how processes such as waves, tides, and currents change the shape of our coast over time. Follow her on Twitter @DrHannahPower.
Dr Michael Kinsela is a Lecturer in Coastal and Ocean Geoscience at the University of Newcastle. Mike investigates the origins and evolution of coastal systems across timescales spanning their geological evolution, historical change and future responses in a changing climate. He has a keen interest in coastal risk management and the environmental and societal challenges posed by coastal hazards and climate change.
Dr Thomas Murray is a research fellow in coastal management at the Coastal and Marine Research Centre, Griffith University. Tom works at the intersection of academia and local and state government in applied coastal process monitoring and management. His research primarily involves a collaborative partnership with the second-largest local government in Australia, the City of Gold Coast, aiding the City in undertaking research into current and future coastal processes, hazards, management, and engineering opportunities/issues.
Dr Andrew Pomeroy is a research fellow at the University of Melbourne’s Coastal and Estuarine Adaptation Laboratory, and a practicing Registered Professional Coastal Engineer and Scientist. His research focuses on quantifying the extent that natural ecosystems can help mitigate coastal hazards associated with waves and coastal erosion, while his professional advice seeks to identify and develop innovative solutions to complex problems that affect coasts, infrastructure, and communities.