Development in areas affected by sea level rise

Here in Lake Macquarie, we enjoy the benefits of living close to the ocean and the Lake. However, our location increases our susceptibility to lake flooding which is impacted by current and projected sea level rise.

Scientists from the Intergovernmental Panel on Climate Change (IPCC), CSIRO and NSW Government report that sea levels are rising and will continue to rise at an accelerated rate. This is due to the expansion of seawater as the oceans warm and the melting of polar icesheets and glaciers.  A link to the latest IPCC AR6 Synthesis Report: Climate Change 2023 is available here.

Council engaged Manly Hydraulics Laboratory (MHL) in 2012, 2015 and 2020 to analyse and report on Lake Macquarie Water Level Trends.  The latest report (available here) concluded that water levels at Belmont gauge have risen by 2.74mm/yr over the last 33 years and 3.05mm/yr over the last 19 years.  This confirms that the lake water level is rising and that the rate of lake water level rise is increasing as predicted.  These results are illustrated in Figure A.1 from the MHL report included below.

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The NSW Government requires councils to factor in sea level rise when planning for future risks from flooding and coastal erosion.  The Lake Macquarie Waterway Flooding and Tidal Inundation Policy provides a framework to help Council and residents respond responsibly and proactively to flooding and sea level rise hazards and risks.  The policy outlines sea level rise planning benchmarks and refers to flood resilient building guidelines that Council and the community can use to facilitate innovative design solutions to adapt to flooding and sea level rise.  

Council’s Property Flooding Information Tool provides a summary of flood hazards for properties in areas where Council has prepared flood studies and/or floodplain risk management plans.  The tool includes information on flood planning levels including any predicted sea level rise impacts that may apply.

Planning for future flood risk and tidal inundation

The Lake Macquarie Waterway Flood Study and Lake Macquarie Waterway Floodplain Risk Management Study and Plan recommend increasing floor heights for new or existing developments to allow for the effects of sea level rise, and establishing Local Adaptation Plans to manage the future risk from flooding and tidal inundation in low-lying suburbs.

Council has been working with lakeside communities to better understand the potential hazards and available options to manage risks from rising lake levels and lake flooding.

The Lake Macquarie Development Control Plan includes provision to reduce the risk to foreshore property from future lake flooding and sea level rise.

Planning for coastal recession

Although there will be beach recession, it is not predicted to pose a significant threat to homes in the period up to 2100. The rate of recession can be slowed by improved dune management and adding dredged sand to beaches.

The Lake Macquarie Coastal Management Program examines the effects of increased sea levels on beach erosion and storm surge.

Engaging our community

As lake levels rise, communities in low-lying areas around the lake will be increasingly affected by lake flooding and tidal inundation.

Local Adaptation Plans are being developed for these areas to guide future decisions, such as how we design and maintain roads and drainage systems, how to make buildings safe and durable, and how we manage foreshore erosion and maintain a healthy lake.

Council is collaborating with residents, businesses, community groups and service providers from our foreshore communities to ensure the decisions made reflect their values and preferences when possible.

Adaptation and climate resilience initiatives outlines our current local adaptation plans and climate resilience programs.

Related Information

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