Northern Australia is renowned for its high rainfall, intact tropical environments and relatively low levels of development. Around two-thirds of Australia's runoff occurs in northern Australia. However rainfall in the north is highly seasonal, with intense monsoonal rains in summer and little rain through winter.
The Water Resources program of the Northern Australia Water Futures Assessment was established to develop a better understanding of water availability in northern Australia. The Water Resources program was completed in 2009 with the release of the final reports from the Northern Australia Sustainable Yields (NASY) project.
Aerial view of the Kimberley Rangelands, WA
Photo by: Dragi Markovic and Department of the Environment
Northern Australia Sustainable Yields project
The NASY project provided the first consistent, robust and transparent assessment of current and likely future water availability across the three jurisdictions of northern Australia, including an assessment of possible future climate implications. The project investigated water resources on a catchment-by-catchment basis, using four different climate and development scenarios. The NASY project provided the science to help governments, industry and communities consider the environmental, social and economic aspects of the sustainable use and management of the water resources of northern Australia.
A key finding of the NASY project was that, despite popular perceptions that northern Australia has a surplus of water, the climate is extremely seasonal and the landscape may be described as annually water-limited.
Other key findings included:
- Northern Australia experiences high rainfall during the wet season, but most of this rain falls near the coast, where there are generally fewer opportunities for engineered storage or diversion. Annual variation in rainfall is high.
- Runoff follows a similar pattern to rainfall; potential dam sites located inland receive less water than coastal areas and suffer very high evaporation rates.
- In the near future, potential evapotranspiration is likely to increase while rainfall is likely to be similar to historical levels, which were generally drier than the last decade, especially in the west.
- Groundwater reserves may provide alternative water source, however more information is needed to access future groundwater availability.
- Shallow aquifers rapidly fill during the wet season and drain through the dry season. Consequently there is limited opportunity for enhanced aquifer recharge.
- There are few river reaches that flow year-round. Those that do are generally sustained by localised groundwater discharge, and have high cultural, social and ecological value.
See CSIRO’s Northern Australia Sustainable Yields Project for details.
The NASY project was one of four sustainable yields projects taking place in Australia.
The outputs of the NASY project may be used to inform future decisions regarding the development of water resources in northern Australia. The outcomes of this program may also inform broader natural resource management issues in the north.