CSIRO has completed, for the Australian Government, an investigation of opportunities for water resource development in key catchments in northern Australia, called the Northern Australia Water Resource Assessment. The Assessment evaluated the feasibility, economic viability and sustainability of water resource development in three priority areas: the Fitzroy catchment in Western Australia; the Darwin catchments in the Northern Territory, and the Mitchell catchment in Queensland.
Much of northern Australia’s land and water resources have not been mapped in sufficient detail to provide for reliable resource allocation, mitigate investment or environmental risks, or confidently build policy settings that can support decisions. Better data are required to inform decisions on private investment and government expenditure, to account for intersections between existing and potential resource users, and to ensure that development benefits are maximised.
In 2013, the Australian Government commissioned CSIRO to undertake the Flinders and Gilbert Agricultural Resource Assessment in north Queensland. This assessment developed fundamental soil and water datasets, and provided a comprehensive and integrated evaluation of the feasibility, economic viability and sustainability of agricultural development in two catchments in north Queensland.
However, this previous study covered only 155,000 km2 (approximately 5 per cent) of northern Australia.
In 2015 the Australian Government released the ‘Our North, Our Future: White Paper on Developing Northern Australia’ and the Agricultural Competitiveness White Paper, both of which further highlighted the opportunity for northern Australia’s land and water resources to enable regional development.
The Australian Government commissioned CSIRO to complete the 2.5-year, $15-million Northern Australia Water Resource Assessment. In collaboration with the governments of Western Australia, Northern Territory and Queensland, they respectively identified three priority areas for investigation: the Fitzroy catchment in Western Australia; the Finniss, Adelaide, Mary and Wildman river catchments around Darwin in the Northern Territory; and the Mitchell catchment in Queensland.
The assessment of each of the three study areas aimed to:
- evaluate the climate, soil and water resources
- identify and evaluate water capture and storage options
- identify and test the commercial viability of irrigated agricultural, forestry and aquaculture opportunities
- assess potential environmental, social and economic impacts and risks of water resource, aquaculture and irrigation development
The three study areas support diverse land uses and contain largely free-flowing rivers that currently sustain areas of high biodiversity, cultural and aquatic ecological value, and support valuable industries.
The Assessment identified that:
- the Fitzroy, Darwin and Mitchell catchments differ significantly in their physical and social characteristics and, as a consequence, the extent to and methods by which agricultural development might occur
- in the Fitzroy catchment, water harvesting (water pumped into ringtanks) could potentially support 160,000 ha growing one dry-season crop a year in 85 per cent of years. Independent of surface water, groundwater could potentially support up to 30,000 ha of hay production in all years
- in the Darwin catchments, a combination of major dams, farm-scale offstream storage and groundwater could potentially support up to 90,000 ha of dry-season horticulture and mango trees
- in the Mitchell catchment, large instream dams could potentially support 140,000 ha of year-round irrigation. Alternatively, water harvesting could potentially enable up to 200,000 ha, growing one dry-season crop per year.
If irrigated opportunities were pursued to their fullest extent they would only occupy about 3 per cent of the Assessment area. Impacts on ecological function are not confined to the direct development footprint and would warrant attention, especially immediately downstream of development and in drier years.
Understanding how diverse stakeholder, investor and developer perspectives interact will be crucial in building and maintaining ongoing social licence to operate for future water and agricultural development.