Overview
Thousands of hectares of soil are potentially suitable for irrigated agriculture across northern Australia but access to sufficient water constrains development.
In recognition of the challenges and opportunities facing northern communities and primary producers, the North Queensland Irrigated Agriculture Strategy (NQIAS) began in January 2012.
CSIRO led one component of the NQIAS, the Flinders and Gilbert Agricultural Resource Assessment (FGARA), with some components undertaken by the Queensland Government and TropWATER (James Cook University).
This two-year, A$6.8 million project, involving more than 100 scientists, provides a comprehensive and integrated evaluation of the feasibility, economic viability and sustainability of agricultural development in these two catchments of North Queensland. The Assessment sought to:
- identify and evaluate water capture and storage options
- identify and test the commercial viability of irrigated agricultural opportunities
- assess potential environmental, social and economic impacts and risks.
Through these means, it seeks to support deliberation and decisions concerning sustainable regional development.
The Assessment differs from previous assessments of agricultural development or resources in two main ways:
- Where previous assessments have focused on single development activities or assets – without analysing the interactions between them – this Assessment considers the opportunities presented by the simultaneous pursuit of multiple development activities and assets. The Assessment uses a whole-of-region (rather than an asset-by-asset) approach to consider development.
- The novel methods developed for the Assessment provide a blueprint for rapidly assessing future land and water developments in northern Australia.
Importantly, the Assessment has been designed to build a knowledge base to inform future development decisions. It does not recommend one development over another.
Key findings
The Assessment concludes that:
- Despite their close proximity, the Flinders and Gilbert catchments differ significantly in their physical characteristics and, as a consequence, the extent to and methods by which agricultural development might occur.
- In the Flinders catchment, farm dams could support 10,000 to 20,000 ha of irrigation in 70 to 80% of years; irrigation may not be possible in very dry years. The precise area under irrigation will, in any year, vary depending on factors such as irrigation efficiency, water availability, crop choice and risk appetite.
- In the Gilbert catchment, large instream dams could support 20,000 to 30,000 ha of irrigation in 85% of years. Again, the precise area under irrigation will, in any year, vary depending on factors such as irrigation efficiency, water availability, crop choice and risk appetite.
- Instream dams enable more reliable irrigated production than farm dams, because they can more easily carry water from one year to the next.
- Significant water use would, in the downstream environment, amplify the environmental and social challenges associated with dry years and would have impacts on commercial and recreational fishing catches that have not been quantified in this study.
For both the Flinders and Gilbert catchments significant water use would, in the downstream environment, amplify the environmental and social challenges associated with dry years.
Reduced river discharges to the Gulf of Carpentaria would have impacts on commercial and recreational fishing catches that have not been quantified in this study.
Large-scale change of land and water use in the catchments is likely to require a wide range of regulatory, social and cultural responses, including consideration of native title implications.