Climate change and its potential impacts on public infrastructure is a significant issue for the Australian government. Approximately 85% of the population lives in coastal areas — areas that are already seeing climate change impacts. Since 2010, AECOM has assisted the Australian Department of Defence (Defence) with understanding risks to assets due to climate change-induced sea level rise, storm surge, and coastal erosion.

This work began with a high-level risk assessment of multiple sites across Australia, prioritising the sites at greatest risk across three timeframes: 2040, 2070, and 2100. The initial assessment established a framework to guide future assessments of climate risk at Defence sites. The findings of the initial study enabled Defence to select sites for further investigation and adaptation planning.

AECOM continued to support Defence in the second stage of the study by completing detailed site assessments of select sites. The detailed site assessment involved physical site inspections to assess current asset condition and facilitate local stakeholder engagement. The site assessments specifically addressed anticipated impacts associated with sea level rise, storm surge, flooding, and coastal erosion, as well as specific issues noted in the initial study. The site assessments provide an analysis of the risks and identified measures for adaptive planning. The adaptation actions identified support the long-term durability of Defence’s operations and facilities at these sites.

To inform the site assessments, AECOM performed detailed modeling of coastal erosion and flooding from storm surge and extreme rainfall. Input from The Commonwealth Scientific and Industrial Research Organisation (CSIRO), Antarctic Climate & Ecosystem Cooperative Research Centres (ACE CRC) and the UK Met Office informed and validated the selection of climate inputs for this assessment. AECOM used existing climate change projections for sea level rise and extreme rainfall to inform the detailed assessments of marine flooding, estuarine flooding and coastal erosion.

In delivering this work, AECOM supported Defence’s internal engagement with the study findings by developing site-based visual summary sheets and animations for use in stakeholder workshops and internal branch briefings. AECOM also facilitated engagement with external stakeholders to discuss broader regional risks and adaptation opportunities.
AECOM produced a suite of reports in recognition of the project’s multiple audiences. For example, we developed an Executive Report summarising the findings for all sites and broader next steps for senior decision-makers at Defence. We also developed Site Reports for site and regional managers. Technical Reports, by contrast, were developed for each site to support engineering audiences using the project outputs.