Mapping opportunities for sustainable wastewater reuse in agriculture
At a glance
To support and expand Australia's agricultural future in the face of climate uncertainty and population growth, we must identify ways to improve water security. The Australian Government’s National Water Grid science program engaged GHD to identify potential opportunities for irrigating large-scale farmland with treated wastewater nationwide. As part of the project, GHD used our spatial decision-making tool, Infrastructure Development Geospatial Options (InDeGO), to identify optimal locations for potential reuse schemes.
The challenge
Around Australia, many towns and cities are reusing their wastewater for agriculture. However, there is an opportunity to uncover where increased wastewater reuse is viable for large-scale agriculture.
Understanding which regions have the right mix of water availability, community readiness, agricultural need and infrastructure feasibility provides the first key step for considering this sustainable and cost-effective option further. This project was a high-level, desktop-based assessment using broad-scale data. Further investigation by regulators, industry and other stakeholders is needed to explore feasibility at a site-specific level.
Our response
GHD applied its proprietary InDeGO tool to initially map and analyse wastewater locations across major areas in Australia. The assessment focused primarily on regions within a 200 km radius of major wastewater treatment plants servicing populations of approximately 50,000 or more. InDeGO enables teams to layer spatial data over real-world constraints, such as proximity to farms, treatment plant capacity and environmental factors. This tool could be used by water managers and industry to consider wastewater reuse opportunities further.
To determine viability, we first needed to understand what could impact the expansion of a reuse scheme. We then considered which wastewater infrastructure and environmental factors were key to deciding the suitability of potential locations: economic viability, wastewater availability and local policies.
Using this knowledge, the team fed national-scale data into InDeGO and developed a geographic shortlist of places where reuse schemes could expand.
Findings and impact
The final report identifies large-scale wastewater treatment plants across Australia with strong reuse potential and highlights key drivers of success, including:
- Reliable volumes of treated wastewater
- Suitable agricultural land nearby (mainly within a 200 km radius of the treatment plant)
- Infrastructure corridors that could support pipeline development
- Supportive local planning frameworks
By exploring reuse opportunities, water managers and industry have been provided with information to better understand wastewater resources.
This project supports GHD’s broader commitment to build a sustainable water future, find solutions that respect natural systems and nurture resilient communities.
The project also showcases how digital tools like InDeGO can bring clarity and confidence to complex water planning decisions, especially when working at a national scale.
To learn how InDeGO can support your next infrastructure or water planning project, explore its features and real-world applications: InDeGO.
For more detail on the project’s methods, site findings and next steps, you can explore the full report.