Posted 5 June 2010
The National Water Initiative (NWI) requires all currently overallocated and overused surface and groundwater systems to be returned to environmentally sustainable levels of extraction. It also requires other less-stressed systems to be maintained at an environmentally sustainable level of use. The National Water Commission's second biennial assessment, Australian water reform 2009, found that the central NWI requirement to make substantial progress by 2010 in dealing with all overallocated and overused systems will not be met. The Commission makes it clear that addressing overallocation therefore remains a central national challenge of water policy reform in Australia.
The National Water Commission considers that if Australia's water use is to be environmentally sustainable, there needs to be:
The NWI Agreement defines an 'environmentally sustainable level of extraction' as 'the level of water extraction from a particular system which, if exceeded, would compromise key environmental assets or ecosystem functions and the productive base of the resource'. While the general intention of this concept is clear, there is a need to detail, extend and illustrate the definition before it can be implemented unambiguously. As a consequence, five years after the signing of the NWI, it has not been possible to develop a nationally consistent picture of the level and distribution of overallocation and overuse across Australia.
Following the approach of the Brundtland Report (1), the Commission takes environmental sustainability to mean 'maintenance of key assets and functions in a condition, which may be less than pristine, but which provide a balance between current environmental requirements and other consumptive demands on water resources while maintaining options for an uncertain future'. Thus, the term includes the sharing of water resources, through water planning, so that important ecosystem services are maintained at an acceptable level of risk.
Because dams and other engineering regulatory structures can affect some environmental assets and ecosystem functions just as much as the physical extraction of water, the concept of 'take' or 'extraction' of water needs to include both volumetric and temporal dimensions. In addition, environmental water needs to be of sufficient quality to achieve the intended environmental objectives. Consequently, the Commission considers that 'extraction' should be interpreted to mean more than volumes of water extracted; it should also take account of the flow regime and the quality of the water provided to the environment.
Within the Murray-Darling Basin, the Murray-Darling Basin Authority will be using its authority under the Water Act 2007 to ensure consistency of interpretation of 'long-term average sustainable diversion limits' across the Basin as it assembles the Basin Plan. Guidelines on water planning and management are currently being developed. These include definitions of key concepts associated with sustainable levels of extraction.
The Commission supports these efforts to eliminate the ambiguities associated with definitions of overallocation and similar terms. The Commission also continues to press for the early return of water to the environment in overallocated systems and argues that ambiguities in definitions should not be used as a pretext for delay.
Good water planning processes are central to establishing environmentally sustainable levels of extraction. Planning processes need to identify aquatic ecosystems that are at risk and the ecosystem services that will be lost if those ecosystems are seriously degraded.
Systems that are assessed to be overallocated or overused, and hence in need of additional environmental water, need to be clearly and publicly identified. At present, there is no agreed national list of overallocated or overused systems. This not only makes it difficult to know whether adequate steps have been taken to deal with overallocation, but also jeopardises other aspects of the NWI such as the risk assignment and interception provisions, which rely on identification of overallocated and overused systems.
The step of determining which environmental assets and ecosystem services should be protected or recovered and the level of risk that can be tolerated is inherently a societal decision. Decisions about which ecosystems to protect are not absolute - they will depend on the current state of scientific knowledge, external circumstances that may change (e.g. the effects of climate change on water availability), and social preferences. Equally, for too long in Australia scientific evidence of overuse of water and declining river health have not been given sufficient consideration. New processes in the Murray-Darling Basin under the Water Act 2007 seek to remedy that while providing flexibility to take account of other considerations as required
The water planning process should be informed by the best available scientific information. Science has a particular role to play because scientists typically possess the best information on the long-term environmental effects of different water allocation decisions. However, because choices have to be made about the environmental assets to be protected and the degree of protection to be afforded to different ecosystems, sustainable levels of extraction cannot be determined by science alone. All groups in society with an interest in the outcomes of water allocation decisions should have effective access to the planning process.
Decisions about how to allocate available water should be transparent so that it is clear to what extent different objectives - including environmental, economic and social objectives - will be met. The knowledge, assumptions and assessments on which a water plan is based, and the uncertainties and risks involved, should be publicly documented. This is not the case at present in all water plans.
Additional environmental water may be needed to achieve the environmental outcomes established in water plans. The Commission strongly supports the use of markets to buy entitlements or allocations from willing sellers. Other options include improvements in the water use efficiency of consumptive water use, improvements in the efficiency of environmental water use, reductions in water theft through stronger enforcement actions, greater control over interception activities, and conditions on licenses to use water.
The Commission's 2009 biennial assessment concluded that environmental water access entitlements do not always enjoy the same level of security as consumptive entitlements (particularly in conditions of prolonged drought). It is a requirement of the NWI that water provided to the environment should have at least the same degree of security as water provided for consumptive purposes. A failure to respect environmental entitlements or environmental watering rules not only jeopardises environmental assets but also raises doubts about the security of irrigators' entitlements. In exceptional circumstances, where environmental allocations must be reduced (for example to meet critical human needs), the Commission argues that the evidence and reasoning should be made fully transparent.
Even when sustainable levels of water extraction have been agreed in a water allocation plan, active management is required to ensure that the agreed environmental water regime is delivered as planned. The 2007 and 2009 biennial assessments found that there are deficiencies both in the way in which environmental water requirements are determined and the way in which the water is managed to ensure that sufficient volumes are delivered at the right times (surface water systems) or maintained at agreed levels (groundwater systems).
Environmental objectives need to be clear. Monitoring and reporting arrangements should be robust. Adaptive management arrangements need to be in place. Environmental water managers need to be adequately resourced and well connected with science resources. They should have reporting and accountability arrangements that avoid conflicts of interest or blurred lines of accountability.
The Commission considers that these actions, backed up by strong commitment from jurisdictions, can lead to the identification of key environmental assets and ecosystem functions, the provision of water regimes for protection of these assets and functions, and the return of overallocated and overused system to environmental sustainability.
National Water Commission May 2010
1. United Nations, 1987. Report of the World Commission on Environment and Development: Our Common Future. United Nations, New York.
Source: National Water Commission sustainable levels of extraction position statement
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