Coastal Hazard Risk Management & Adaptation Planning (CHRMAP) - Frequently Asked Questions
Throughout our planet’s history, sea level has risen and fallen over millions of years. Strong scientific evidence indicates global sea level has risen more consistently over the past century. Current projections for sea level rise are based on a vertical sea level rise of 0.9 metres over a 100 year period to the year 2110 (SPP 2.6). Sea level rise is being linked to climate change which has been observed as an average rise in temperature of the Earth’s climate over the past century, also known as global warming.
Global warming causes a rise in sea level in two primary ways. First, as the global temperature increases the seawater expands, taking up more space in the ocean basin and causing a rise in water level. The second mechanism is the melting of ice over land which then adds water to the ocean.
The City of Wanneroo has chosen to complete the CHRMAP in two main components. The first component is complete a coastal vulnerability study and hazard map (Part 1). The results of this study are available on the City’s website and mapping tool.
The second component of the CHRMAP utilises community feedback to help determine the potential risk and available adaptation strategies to manage coastal vulnerability along the City’s coastline.
The City’s CHRMAP does not include detailed information about the risk management and adaptation planning for undeveloped areas along the coastline for which the City is not currently managing. The relevant developer for each foreshore area is responsible for developing their own CHRMAP consistent with SPP 2.6 and the overall strategic direction of the City’s CHRMAP.
The study reviewed historical studies and used scientific methodology to identify coastal areas and associated assets that may be vulnerable to coastal processes. How vulnerable an asset is depends upon how exposed the asset is to the sea inundation and erosion; the sensitivity of the asset; and the ability for that asset to adapt to these changes.
Hazard maps were developed as a component of the CHRMAP Part 1 study to illustrate the areas of coastline that may be impacted over the next 100 years. The vulnerability of the coastline is defined by the following timeframes:
- Present day – brown line;
- 2030 – green line;
- 2050 – blue line;
- 2070 – purple line;
- 2090 – pink line; and
- 2120 – red line.
Copies of the hazard maps are available within the CHRMAP Part 1 study, available by clicking below and within the City’s online mapping tool.
Key areas that may be impacted over the next 35 years are included in Table 1:
|Priority Ecological Community||Two Rocks||2030|
|Sovereign Drive & residential lots||Two Rocks||From 2050|
|Beach access road to 'The Spot'||Two Rocks||2050|
|Capricorn Groyn car park||Yanchep||2050|
|Brazier Road car park adjacent to Yanchep Lagoon||Yanchep||2030|
|Residential lots west of Brazier Drive||Yanchep||From 2030|
|Heritage site Karli Springs||Alkimos/Jindalee||2050|
|Residential lots west of Clarecastle Retreat||Mindarie||2050|
|Priotiy Ecological Community||Mindarie||Present day|
Table 1 The nine key areas of vulnerability along the City of Wanneroo’s coastline, as determined by Part 1 of the CHRMAP study.
The City conducted a Values Survey in August 2016 to identify what the community values about the City’s coastline. The survey results have been combined with information on the potential impact and vulnerability of the City’s coast to sea level rise and erosion to complete a risk assessment for the high risk sites along the City’s coastline. The outcomes of the risk assessment will help the City to identify which sites should be prioritised in the future.
In September 2017, the City prepared draft preliminary adaptation options for the City’s coastline and each of the specific key risk areas. The community was invited to comment on potential adaptation options for vulnerable coastal areas, through a survey, open from the 20 November 2017 to the 18 December 2017.
The results from the survey were collated to help to determine the types of adaptation options that may be used along the City’s coastline in the future. A draft Final CHRMAP report is currently being drafted and will be presented to Council in late 2018.
This study is planned to be repeated every five to ten years to ensure the vulnerability of assets are reassessed. This will assist in reviewing any potential changes in the impact of coastal processes and to review the effectiveness of implemented adaption plans.
How can I find out more information?
Further information is available by clicking below:
Should you have any further queries, please contact our Environmental team on 9405 5372.