In northern Australia, three major hydrogeological systems are listed as being highly productive: the Canning Basin in Western Australia, the Great Artesian Basin in Queensland and the Daly Basin in the Northern Territory. Each of these systems is unique and, as such, needs to be managed in ways that consider local aquifer characteristics while ensuring compliance with state and national regulatory frameworks. The National Water Initiative (NWI) of 2004 requires that States compile water allocation plans which, in turn, require sufficient levels of understanding of these aquifers. In some cases, such as in the Pilbara region of Western Australia, the water allocation plan does not take into account all forms of water extraction while, in other cases, the net flow of water from aquifers is well understood but is not sustainable over the long term. The characterisation of aquifers, their interconnectedness, and how they affect surface water resources and Groundwater Dependent Ecosystems (GDEs) is a major step in gauging sustainability and scope for development. Ultimately, however, the viability of an aquifer depends on how frequently it can be recharged – and there is evidence that significant natural recharge events for some aquifers only occur on a timescale of millennia. In the following analysis, examples will be given from just some of the major users of water from aquifers in northern Australia to demonstrate different levels of knowledge around aquifers and management practices.
- Northern Australia contains three major subterranean water systems, with one each in Queensland, Western Australia and the Northern Territory. Each of these systems is unique.
- The viability of an aquifer depends on how frequently it can be recharged – and there is evidence that significant natural recharge events for some aquifers only occur on a timescale of millennia.
- Ancient aquifers not only supply water for industry and towns, but they are also crucial for supporting biodiversity and have high cultural values that date back tens of thousands of years.
- In central Australia, any water used is a net loss from an aquifer system that last saw significant recharge thousands of years ago. The management of this resource is yet to achieve the necessary careful exploitation for long-term sustainability.
- Groundwater resource management across northern Australia must consider very localised aspects of aquifer characterisation and use, while still being able to fall under cross-jurisdictional policies such as the National Water Initiative.