Our coastal future - Port, Leighton and Mosman beaches coast plan
The City of Fremantle, in partnership with the Town of Mosman Park and the Department of Planning, has completed the Coastal Hazard Risk Management and Adaptation Planning (CHRMAP) project resulting in the Port, Leighton and Mosman Beaches Coastal Adaptation Plan. The full plan can be accessed via the link at the bottom of this page.
Other stakeholders who participated in the implementation of the project were Fremantle Ports, Department of Transport, Department of Environmental Regulation, Town of Cottesloe and Perth NRM Coastal and Marine Program.
This project is funded by the Western Australian Planning Commission through the Coastal Management Plan Assistance Program.
Objectives / Benefits
The aim of this project is to understand what coastal hazards (such as erosion and inundation) mean for the community and their assets, and to plan for and adapt to the possible impacts.
The City engaged with key stakeholders, including community representatives that are affected to produce an adaptation plan.
This project was undertaken in these five phases:
Phase 1 - Establish context
Consider the natural coastal processes and find out from the community what they value about the coast at Port, Leighton and Mosman beaches.
Phase 2 - Coastal risk identification and vulnerability assessment
Map the type and impact of coastal hazards for now and the future. This included how predicted sea levels might impact built and natural assets. This was overlaid with the cultural, social, environmental and economic values from the community and stakeholder consultation to identify areas of risk.
Phase 3 - Coastal hazard risk analysis and evaluation
In this phase the coastal hazard risks were analysed against the community and stakeholder values to give a range of tolerable coastal risks.
Phase 4 - Coastal adaptation planning
A plan was drafted for the most appropriate coastal adaptation responses to identified risks. The adaptation responses were defined by evaluating the methods against multiple social, economic, environmental and economic criteria.
Phase 5 - CHRMAP reporting
The project report includes all the outcomes of each phase and provides a guide to the adaptation plan for future coastal use and development for the respective local government authorities.
Community and stakeholder engagement
Throughout the life of the project, the City of Fremantle and Town of Mosman Park has informed and consulted with the community and stakeholders. This included an initial values survey, then additional awareness-raising of the identified coastal vulnerability as well as determining whether community views differed when considering the vulnerability of the coastline at specific locations, and finished with an invitation to comment on the final report before it was adopted by Council.
What we did
The project included two key components that have been running in parallel – a technical analysis to understand the coastal hazards and risks and a community values survey to understand what aspects of the beach and coastal environment are valued by the community within the project area.
What is the purpose of estimating coastal hazards?
A risk assessment was undertaken to determine whether assets and their associated values and functions within a given area are at risk of being impacted by coastal hazards. The risk assessment was guided by community values, modelling and evidence-based research and involved examining the assets within the Port, Leighton and Mosman Beach areas and determining the level of risk (low, medium or high) over the short, medium and long term. There are four categories of assets:
• Social: Elements that facilitate access to the coast.
• Infrastructure: Physical items that service the population e.g. roads, rail, utilities.
• Environment: Natural elements and open spaces.
• Economic: Items that have a financial component and / or support and / or generate employment.
By understanding the level of risk on the assets in the area, we are able to investigate management and adaptation measures that are appropriate to minimise the risks to a more acceptable level. Generally the risks identified were of an acceptable or tolerable level, however some were identified as intolerable or unacceptable in either the short, medium and / or long term for the different beaches.
What are the likelihoods and timeframes of coastal hazards?
The coastal hazards of erosion and inundation were estimated at short (2030), medium (2070) and long term (2110) to align with coastal planning timeframes and at three likelihoods: Almost Certain, Possible and Rare. In general, the impact of inundation on Port, Leighton and Mosman Beaches is identified as being relatively insignificant compared to the potential impacts of erosion due to the elevation of the foreshore dune system. The short term results are presented in the hazard maps below, as these are the primary consideration for immediate adaptation planning.
The coastal processes used to calculate future erosion hazard areas at Port Beach include storm erosion, a long term (23 year) trend of erosion and sea level rise. Hazard maps presented for Port Beach assume that the sea wall adjacent to Port Beach Road does not contribute to beach protection, demonstrating the potential extents of erosion if the seawall is not included in future coastal adaptation solutions. In the short term the almost certain erosion hazard for Port Beach extends across a significant portion of the carpark and dune areas and across Port Beach Road at the southern end of the study area. The assets identified as being at risk were the beach access points, coastal path, off-street parking, kiosk, change rooms and public furniture (short, medium and long term) Port Beach Road Reserve and freight rail (medium and long term) and Fremantle Port land (long term).
Leighton Beach has an accreting sandy foreshore. The processes identified as contributing to future erosion hazard areas were short term storm erosion and sea level rise. In the short term, the almost certain erosion hazard area is contained within the dune system except in the northern extents of Leighton Beach. The possible and rare erosion hazard areas extend into the Leighton Parklands and change rooms.. The assets identified as being at risk were the Fremantle Surf Life Saving Club (medium and long term), the Port Beach Road Reserve, coastal paths,and off-street parking (long term).
Erosion in the short term at Mosman Beach will be caused by sea level rise and a slow but consistent erosion of the dune and cliff base causing slope erosion. The future erosion hazard area identified is significantly less than at Leighton and Port Beach, however, the width of the dune system and the elevation of the land behind mean that this section of the coast has a reduced capacity to buffer and repair from erosion events. The areas identified as being at risk were beach access points (short, medium and long term), coastal paths (medium and long term) and off-street parking (long term).
What was said in the survey?
The community values survey examined a range of aspects to determine how the beach is used, understand the unique qualities of the project area and determine what is it about this area that is most valued by the community.
The community values survey sought feedback from the community, particularly in relation to recreation, coastal amenity, community facilities, entertainment and social aspects, private benefits and employment and economic benefits.
The survey was available for completion online at the City of Fremantle website in July and August 2016. Members of the project team also visited the project area on 24 July 2016 to discuss the project and complete surveys with the community.
A positive response was received from the local community with a total of 306 surveys completed. Of those respondents who indicated where they lived, 58% were from the City of Fremantle, 11.2% from Mosman Park, 4.7 from the Town of Cottesloe and 26.1% were from another area. The majority of respondents (93.8%) lived within a 10-15 minute drive.
Survey respondents were also asked to determine the level of importance of various beach elements by establishing why they engage with them at this location and to what extent their lifestyle would be impaired if they were lost. The graphs below indicate that recreation opportunities and coastal amenity within the project study area have a significantly greater value to the community than other beach elements. 85% of respondents are either unable to easily access these experiences elsewhere or prefer not to and 90% of respondents indicated that the loss of these experiences would negatively impact their way of life.
What will the survey results be used for?
To arrive at the most appropriate options for coastal adaptation a detailed assessment, including the community values identified in the survey and the outcomes of the technical risk assessment, will be undertaken and used to prepare the final report.
What are we doing now?
The City of Fremantle is implementing the recommendations made in the report and will form long-term projects. We have commenced planning for two of these projects.
We are again partnering with Fremantle Ports to undertake a project that will provide information that can be used to assess and design coastal engineered adaptation options for Port Beach. The Town of Mosman Park, Town of Cottesloe and Fremantle Ports will also participate in a project that will obtain data to monitor trends in coastal sediment transport that will enable more accurate identification of site specific risks and appropriate coastal adaptation options. They will be implemented subject to funding and budget availability.
Coastal processes threaten private and public infrastructure and highly valued conservation and social recreation access. More recent research into coastal processes in this section of coast points to a need to revise the City’s approach to coastal management decision making. The existing Port and Leighton Beaches Management Plan 2001 and the Mosman Beach Management Plan 2003 require updating to direct investment for appropriate coastal erosion management responses and inform future development.
Coastal Management Plan Assistance Program (CMPAP) grants are provided by the Western Australian Planning Commission (WAPC) to implement and enhance the State Coastal Planning Policy (SPP 2.6)
The City of Fremantle in partnership with the Town of Mosman Park (ToMP) have been successful in an application for CMPAP funding to prepare a Coastal Hazard Risk Management and Adaptation Plan (CHRMAP) for the coastal area that includes Port, Leighton and Mosman Beaches. A CHRMAP involves understanding future coastal erosion and inundation hazards, evaluating the risk of the hazards, and preparing an adaptation plan.
To assist is addressing coastal vulnerability the Department of Transport offers a Coastal Adaptation and Protection Grants program to undertake works identified in a coastal hazard risk management and adaption planning process.
For more information on this project, please contact:
City of Fremantle
Town of Mosman Park
This joint partnership project is funded by the Western Australian Planning Commission through the Coastal Management Plan Assistance Program.