As floods become more frequent, longer lasting and more severe, communities across Australia are searching for smarter, more sustainable ways to manage risk and build resilience.

A team of researchers from the Australian National University (ANU) have partnered with communities in New South Wales and Queensland to explore how Nature-based Solutions (NbS) can help. These solutions aim to work with nature, rather than against it, to reduce the impacts of flooding and protect people, property and the environment. From this, a practical guide to implementing Nature-based Solutions for flood resilience has been created.

Why risk is increasing and flood solutions are needed

Over time, Australia’s landscapes have changed in ways that have reduced its ability to manage floods. This is through:  

• land clearing and soil compaction
• drainage of wetlands
• levee banks separating floodplains from rivers
• erosion and modification of streams
• infrastructure such as roads and railways creating barriers to flood waters
• urban development on flood-prone land.

As a result, floodwaters move faster and hit harder, putting communities at greater risk.

Climate change is making floods more frequent, severe and unpredictable due to the increased rainfall and intensification of the water cycle. We therefore need to complement traditional flood management approaches. 

How Nature-based Solutions could help flooding

Nature-based Solutions can provide effective flood risk reduction while maintaining ecological integrity and restoring ecological and hydrological functions.

They aim to slow floodwaters, reconnect rivers with their floodplains, and restore natural buffers like wetlands.  

Practical examples include:

afforestation, re-establishment of riparian vegetation, wetlands, flow barriers such as leaky weirs and restoration of paleochannels. They can also include relocating or raising infrastructure, changing land use on floodplains and in catchments and reconnecting rivers to floodplain wetlands.

Working in partnership with local communities

With input from communities in New South Wales and Queensland, a set of national guidelines has been developed to help implement Nature-based Solutions in diverse local contexts. The Guidelines provide a guide to the design of Nature-based Solutions in catchments to mitigate flooding of urban areas and to improve catchment health. The Guidelines show how with careful planning and design, combining a range of Nature-based Solutions can effectively mitigate moderate floods (up to a 1-in-20-year flood) and reduce the impacts of rare floods (a 1-in-100-year flood).

These guidelines include:

• Frameworks and processes to evaluate options to minimise the impacts of floods.
• Useful information about the types of Nature-based Solutions and how they can be used for flood mitigation.
• Methods to evaluate the impacts and co-benefits of integrating the Nature-based Solutions.
• Innovative and practical approaches to flood risk mitigation in each community.

The project was awarded $1,204,039 (excluding GST) in Round Three of the Disaster Risk Reduction Package (DRRP), and a further $303,000 in Round Four of the DRRP, taking the total Commonwealth funding for this project to $1,507,039 (excluding GST).

This is an investment towards helping communities design flood mitigation solutions that are more sustainable, more adaptable, and better suited to Australia’s unique environment.

To learn more, the following resources are now available for viewing: Nature-based Solutions for flood mitigation in Australia - National Guidelines | ANU Institute for Climate, Energy & Disaster Solutions