TheCropSite.com- news, features, articles and disease information for the crop industry

Featured Articles

Water, Agricultural Development in the Flinders, Gilbert Catchments of North Queensland

13 March 2014

CSIRO has completed, for the Australian Government, an investigation of opportunities for water and agricultural development in the Flinders and Gilbert catchments of north Queensland.

Each catchment offers the possibility of irrigation developments approaching (Flinders) or exceeding (Gilbert) the scale of the current Ord River Irrigation Area.

Key findings

The Flinders and Gilbert Agricultural Resource Assessment has, for each catchment:

  • identified and evaluated water capture and storage options
  • identified and tested the commercial viability of irrigated agriculture opportunities
  • assessed potential environmental, social and economic impacts and risks.

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.

The Flinders catchment


The Flinders and Gilbert catchments in north Queensland


  • 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 per cent 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 per cent 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.

The Flinders catchment has the potential to support irrigated agricultural development (10,000 to 20,000 ha), approaching the scale of the current Ord River Irrigation Area, in 70 to 80 per cent of 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.

Irrigation on this scale would be based on water stored in on-farm dams, pumped from the river or captured as overland flow during flood events. Irrigation of this type could be widely distributed across the catchment or concentrated into a smaller number of irrigation areas. The Flinders catchment does not have locations suited to large or cost-effective instream dams.

Reliance on relatively shallow on-farm dams makes it unlikely that water could be carried over from one year to the next. Under these conditions, the area of irrigated agriculture would vary significantly from year to year and may not be possible in very dry years.

This variability challenges the commercial viability of irrigation in the Flinders catchment. Under the development scenarios examined, the high capital costs of on-farm dams and land development (approximately $10,000 per ha of irrigated land) precluded commercial returns on investment where farmers paid the whole cost.

Where third-party capital investment in water storage and delivery was examined commercial returns on irrigated agriculture were possible, but required consistent achievement of near potential yields, which can be challenging in the northern Australian environment.

The Gilbert catchment

The Gilbert catchment has the potential to support irrigated agricultural development (20,000 to 30,000 ha) exceeding the scale of the current Ord River Irrigation Area. The precise area under irrigation will, in any year, vary depending on factors such as irrigation efficiency, water availability, crop choice and risk appetite.

Irrigation on this scale would be based on water stored in two large instream dams and delivered to an irrigation development up to 70 km downstream. Irrigation of this type would probably be concentrated into one area, capable of production sufficient to sustain a local cotton gin or sugar mill.

The capacity of instream dams would enable water to be carried over from one year to the next, and it is likely that production of greater than 20,000 ha could be achieved in 85 per cent of years.

Under the development scenarios examined, the high capital costs of instream dams and water delivery infrastructure (approximately $1 billion) precluded commercial returns on combined investment in water assets and irrigated farming. Where third-party capital investment in water storage and delivery was examined commercial returns on irrigated agriculture were possible, but required consistent achievement of near potential yields, which can be challenging in the northern environment.

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.

March 2014

Share This

Our Sponsors

Partners


Seasonal Picks

Country Dance