Coastal erosion is by far the most complex issue that the Shire of Gingin has had to address. Our coastline is highly valued - it provides us with places and spaces to live, do business, be active and enjoy. However, the coastline is not static – it is constantly changing through storm events, predicted sea level rise, and the changes that people make to it.
These coastline changes are now becoming much more noticeable and happening more rapidly. For this reason, local governments throughout Western Australia have been undertaking studies to understand the impacts of these coastal processes, particularly where people live.
The Shire is no exception to this. We are trying to understand how our coastline will be impacted by the coastal processes of ‘erosion’ and ‘inundation’. In 2019 a Coastal Hazard Risk Management Adaptation Plan (CHRMAP) was undertaken for Lancelin, Ledge Point and Seabird, and in 2020 a Coastal Inundation Study for Lancelin, Ledge Point, Seabird and Guilderton was prepared.
However, there remained gaps that required further work. In August 2020, the Shire was successful in obtaining funding through the 2020/21 Coastal Management Plan Assistance Program (CMPAP) grants funding stream to bolster the 2019 CHRMAP to include the Guilderton coastline and integrate it with the Inundation Study completed in 2020. In addition, in June 2021, further CMPAP funding was gained to prepare a Coastal Management Strategy.
These documents will provide a comprehensive understanding of how our coastline will be impacted in the future, and how we can plan for and manage these changes in the future.
All stages of the development of the CHRMAP, CMS and the Summary have been overseen by, and with input from, the Project Steering Committee comprising representatives from Department of Planning, Lands and Heritage, the Department of Transport, the Shire’s Coastal Erosion Advisory Committee, Shire representatives, and the project consultants (Shape Urban, Water Technology, Far Lane and Propagule).
A CMS has been prepared, however further consultation is required prior to final adoption. This will be advertised in due course.
Please note that the project webpage is no longer active. However, you can still access the interactive map, where previous comments and feedback can be viewed.
What is 'Our Coast, Our Journey'?
Our coast is important to us all. It provides us with places to live, do business, exercise and enjoy. However, the coast is constantly changing through storm events, rising sea levels and the changes that people make to the coastline (buildings, hard coastal structures and dune/beach changes). As the coastline begins to change, it can impact the infrastructure (for example footpaths, roads, houses, beach access, services etc) in the ‘coastal zone’ and how the coast can be used.
The Shire of Gingin recognises how important the coast is. This project will help the Shire to understand ‘coastal hazards’ and ‘risks’ that may impact the coastline in the future and what the options are for managing these. The Shire is preparing an integrated Coastal Hazard Risk Management and Adaptation Plan (CHRMAP) for its coastal townsites and a Coastal Management Strategy (CMS) for its coastlines.
These documents will give us a comprehensive and integrated understanding of how our coastline will be impacted in the future and how we can plan for and manage these changes in the four coastal townsites and along the coast.
Why are we preparing an integrated CHRMAP when we have already done a CHRMAP and Coastal Inundation Study?
In 2019 Cardno prepared a CHRMAP for Lancelin, Ledge Point and Seabird that examined erosion risks and adaptation options. In 2020 Baird prepared an Inundation study for Lancelin, Ledge Point, Seabird and Guilderton.
However, there are some pieces of the puzzle missing so the Shire is now working to fill those gaps. This includes risk assessment and adaptation options for Guilderton, responses to inundation risks for Lancelin, Ledge Point, Seabird and Guilderton, and an assessment of what else has changed across the four coastal towns. This will give us a comprehensive and integrated understanding of how our coastline will be impacted in the future and how we can plan for and manage these changes in the four coastal townsites.
In addition, CHRMAPs contain a significant amount of technical information which can be difficult to understand. As a result, we will be producing a summary document that provides this information in an easy-to-read document using simple language.
What is a CHRMAP?
CHRMAP is the acronym for a ‘Coastal Hazard Risk Management and Adaptation Plan’. It is a study prepared to communicate information about future coastal planning. It includes a technical assessment to understand the existing and predicted coastal processes, includes a social assessment to understand the community values associated with the coastline being studies, and considers financial and environmental implications.
The State government’s Coastal Hazard Risk Management and Adaptation Planning Guidelines (July 2019) provide guidance for decision makers to develop and implement effective CHRMAPs. You can view these guidelines here.
The key components of a CHRMAP are:
- Understanding the local environment and community values.
- Assessing how much things can cope with the impact of climate change.
- Identifying the risks (likelihood of an event occurring and the consequences of that event occurring).
- Analysing the findings and evaluating the management options.
- Identifying the adaptation options.
- Identifying funding options, monitoring and review of frameworks
The CHRMAP will estimate where the coastline is likely to be in the short, medium and long-term future.
By understanding where the coastline is likely to be in the future, it allows us to understand what infrastructure may be impacted by coastal processes and investigate which options for managing these impacts might be appropriate in particular areas.
CHRMAPs contain a lot of text which is hard to understand. How can I find out what these words mean?
CHRMAPs do contain a lot of technical terms which can be difficult to understand. Key coastal processes and terms used in coastal planning can be found in the Glossary of Terms below, or by viewing State Planning Policy 2.6 here.
Glossary of Terms
The following terms are commonly used in coastal planning and will be used regularly throughout the project consultation.
COASTAL ADAPTATION
'Adaptation' means an adjustment in natural or human systems in response to actual or expected stimuli or their effects, which moderates harm or exploits beneficial opportunities. Adaptation is the means for maximising the gains and minimising the losses associated with coastal hazards over the planning timeframe.
When we talk about the ways in which we make changes to the coast to manage the impacts of coastal processes, there are typically four main options we can use:
- Avoid - do not allow new development to occur in areas that have been identified to be affected by coastal hazards.
- Planned or managed retreat - relocate or remove things which may be at intolerable risk of damage from coastal hazards.
- Accommodate - use design measures and/or management strategies that make the risks from coastal hazards more acceptable.
- Protect - undertake works that will preserve the foreshore, public access, public safety and significant property and infrastructure.
OTHER TERMS
Other commonly used terms include:
‘coastal hazard’ means the consequence of coastal processes that affect the environment and safety of people. Potential coastal hazards include erosion, accretion and inundation.
‘coastal processes’ means any action of natural forces on the coastal environment.
‘coastal zone’ includes the areas of water and land that may be influenced by coastal processes.
‘erosion’ – refers to shoreline movement where the shoreline shifts landward reducing the width of a coastal foreshore reserve and/or the distance to a fixed feature on the adjoining land.
‘intolerable’ – means risk that is unacceptable in any circumstances or at any level.
‘inundation’ – means the flow of water onto previously dry land. It may either be permanent (for example due to sea level rise) or a temporary occurrence during a storm event.
‘risk’ is specified in terms of an hazardous event or circumstances and the consequence that may flow from it. Risk is measured in terms of a combination of the likelihood of an event occurring and the consequence of that event occurring.
‘storm surge’ – means the increase in water level at the shoreline due to the forcing of winds (wind-setup) and atmospheric pressure.
‘vulnerability’ – means the degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change, including climate variability and extremes. Vulnerability is a function of the character, magnitude, and rate of climate change and variation to which a system is exposed, its sensitivity, and its adaptive capacity. Systems that are highly exposed, sensitive and less able to adapt are vulnerable.
What is a CMS?
A Coastal Management Strategy (CMS) is a plan that provides recommendations and specific actions for managing the coastline. The plan proposes ways to protect existing assets, modify or relocate assets and suggests new assets to enhance parts of the coast and protect its value to the community.
For the Shire of Gingin, the design scenarios will take into account the impacts of coastal erosion and inundation highlighted in the integrated CHRMAP that is being completed. The CHRMAP will identify options to mitigate coastal hazard risks and assess the most preferable options. Options include not allowing new development to occur in areas that have been identified to be affected by coastal hazards, relocating or removing things which may be at intolerable risk of damage from coastal hazards, using design measures and/or management strategies that make the risks from coastal hazards more acceptable, and/or undertaking works that will preserve the foreshore, public access, public safety and significant property and infrastructure.
The CMS will recommend other actions that will support implementation of the short-term requirements of the CHRMAP.
What options are there for managing coastal risks?
There are four main adaptation options (adjustments that can be made) for managing coastal risk.
- Avoid – not allowing new development in areas identified to be affected by coastal hazards.
- Planned or managed retreat – relocating or removing things which may be at intolerable risk of damage from coastal hazards.
- Accommodate – design measures and/or management strategies that make the risks from coastal hazards more acceptable.
- Protect – works that will preserve the foreshore reserve, public access, public safety and significant property and infrastructure.
Different options are appropriate for different locations taking into consideration the type of coastline, community values, environmental impacts and cost implications.
Why is the CMS being prepared now?
The area of coastline from above the Nilgen Nature Reserve down to the Wilbinga Dunes, including Lancelin, Ledge Point, Seabird and Guilderton, contains valuable assets such as beach stairs, other beach access, seating, shelters and parkland. The area has been directly impacted by erosion and flooding over many years.
The CMS will address these negative impacts and proposes ways to protect and enhance the assets within this area or manage the impacts effectively. It is important to plan so that the money spent on rehabilitation and protection of the area is put into effective treatments.
The CMS will also recommend other actions that will support implementation of the short term requirements of the CHRMAP.
Who is preparing the CHRMAP?
The Shire is preparing the CHRMAP and CMS with the assistance of a team which is made up of technical specialists in:
- Coastal management (coastal hazard and risk assessment)
- Statutory and strategic planning
- Community engagement
- Environmental science
- Landscape architecture
How will the CHRMAP and CMS impact my property?
The CHRMAP will identify the areas that are at risk of being impacted by coastal hazards and when they are likely to occur, and will make recommendations on the appropriate management options for different areas.
The CMS will propose actions and projects that help to preserve and protect natural and other infrastructure such as playgrounds, parks and picnic areas. Some of the actions may include restricting or reducing access to certain areas, reducing some of the activities allowed in an area or relocating activities.
The impact on your individual property depends on where it is located, as the hazards and risks vary throughout the coastline.