Water is a critical resource management issue in Australia and is recognised as being “part of Australia’s natural capital, serving a number of important productive, environmental and social objectives” (IGA-NWI, 2004, p. 1). The demand for water for residential supplies, agriculture, industry, and other human needs has increased with population in the past and solving conflicts surrounding allocations for these uses and for ‘environmental flows’ are a key element of national water reform. One of the many competing ‘uses’ for freshwater flows are environmental flows into estuaries, the highly valuable receiving-waters of all seaward draining waterways.

The need for reform of water resource policy has long been recognised and formally entered into the agenda of the Council of Australian Governments (COAG) in June 1993. The result was a report commissioned from a ‘Working Group on Water Resource Policy’ ultimately leading to the Council endorsing in February 1994 a framework for the reform of the Australian water industry. A key component of the framework was the consideration of allocations for the environment and in particular that “environmental requirements, wherever possible, will be determined on the best scientific information available and have regard to the inter-temporal and inter-spatial water needs required to maintain the health and viability of river systems and ground water basins” (COAG Communiqué, 1994, section 4d). Although the framework referred generally to ‘river systems’, estuaries are not mentioned specifically and the major focus as been on freshwater reaches of Australian rivers (i.e. those of prime interest to the water resources industry).