Welcome to the Cocos Keeling Island CHRMAP project page
The coast is important to everyone. It provides places to live, do business, exercise and enjoy. However, the CKI community faces challenges from coastal hazards like erosion and flooding - Home Island frequently floods, affecting daily life, while West Island is also at risk from erosion and rising sea levels. Since 1992, rising sea levels have posed a significant threat, increasing by 4mm annually.
A Coastal Vulnerability Study (CVS) prepared in 2021 by the Australian Government and other key stakeholders highlighted the risks associated with erosion and flooding for the next century. Subsequently, the Australian Government has collaborated with the Western Australian Department of Planning, Lands and Heritage (DPLH) to develop a Coastal Hazard Risk Management and Adaptation Plan (CHRMAP) to support the Shire of CKI (the Shire) and the community of CKI to make long term decisions that adequately consider future risk.
Latest News
April 2026 Project Update: Final CHRMAP now released
After an extensive review of public submissions and all historical technical analysis and investigations, the final CKI CHRMAP is now publicly available.
The CHRMAP finds that all assets, infrastructure and people on CKI will be significantly impacted by coastal erosion and inundation in the short, medium and long term. The CHRMAP recommends immediate actions to ensure effective decision-making and support strategic planning. These actions include further studies, emergency management planning, and heritage management plans.
Importantly, we have heard the community clearly about meaningful engagement about next steps, and the CHRMAP prioritises ongoing collaboration with the community, which commences immediately. Opportunities to meet the project team and a process to establish a Community Reference Group will occur in the coming weeks. This will embed the next steps following the CHRMAP as an ongoing partnership approach in managing and adapting to the coastal hazard challenges facing CKI.
Please follow the project using the +Follow button above to ensure you are kept up to date with ongoing opportunities to collaborate on coastal hazard management.
Coastal Mapping Descriptions
Between 2018 and 2021 the Australian Government in collaboration with the WA Department of Planning, Lands and Heritage commissioned a Coastal Vulnerability Assessment for Home Island and West Island (CVA report). The CVA report identifies coastal hazard risks and assesses the vulnerability of built and natural assets to erosion and inundation hazards, in accordance with the requirements of the WA government’s coastal policies.
Based on these assessments, coastal hazard maps were produced for Home Island and West Island over the next 100 years. The maps show areas projected to be affected by coastal hazards such as erosion and inundation. It is important to bear in mind that these projections are based on the possible impacts from a combination of estimated sea level rise and extreme weather events, as well as historical observations of relevant environmental factors. How the erosion hazard and inundation mapping was developed is explained in more detail below. These areas were calculated using the methodology prescribed in WA State Planning Policy 2.6 – Coastal Planning (SPP 2.6) and have been identified for a 100-year planning timeframe, broken up into 2018, 2031, 2068 and 2118 timeframes. The maps have been prepared by qualified coastal specialists and reviewed by the Australian Government.
The methodology for calculating coastal hazard areas does not take into account future action that may be taken to adapt to coastal hazards.
Familiarise yourself with the projected coastal hazard lines and the inundation mapping to see how erosion and inundation have been projected to affect the coastline and the coastal settlements on Home Island and West Island.
The hazard lines represent the combined allowance calculated from the following factors as outlined in SPP 2.6:
- Predicted erosion under a severe storm - storm erosion from a potential one in 100-year storm event (S1);
- The historical rate of shoreline change - calculated as 100 times the historic annual rate of erosion (S2);
- Predicted sea level rise - calculated as 100 times the adopted sea level rise value of 0.9 metres over a 100-year timeframe (S3).
Home Island and West Island have sandy coastlines. The line on the hazard map is a combination of S1, S2 and S3, plus the 0.2 metre/year uncertainty allowance provided for in SPP 2.6 for sandy coastlines.
The erosion hazard lines provide an indication of the possible extent of erosion at each of the dates indicated by the lines if a combination of these factors occur.
The dates should not be read as precise; rather, the erosion is likely to occur at a time close to the year but could occur much sooner or much later. For this reason, it is recommended that monitoring and review is regularly undertaken.
A modelled approach using simulation periods was used to map inundation areas. The inundation areas represent the peak steady water levels, i.e. still water levels plus an allowance for wave-driven water levels, including overtopping of coastal structures, in accordance with SPP 2.6.
The inundation areas are shown as Australian Height Datum (AHD).
