Environmental Water Requirements of Groundwater Dependent Ecosystems
Technical Report Number 2
Sinclair Knight Merz Pty Ltd
Environment Australia, November 2001
ISBN 0 642547696
About the report
The National River Health Program (NRHP) aims to help build the foundation for protection of Australia's water resources. As a component of the NRHP, Environment Australia (EA) has commissioned this report to define issues relating to the environmental water requirements of groundwater dependent ecosystems (GDEs).
The concept of making provision of water for environmental purposes is not a new one. Environmental flow allocations for surface water systems have been considered in Australia for a decade or more and there is an extensive national and international literature on the topic (see Arthington and Zalucki 1998). By contrast there is limited, although growing, experience in the provision of water to meet the needs of groundwater dependent ecosystems.
Groundwater resources in many parts of Australia are facing increasing pressure from consumptive uses for agricultural, mining, urban and commercial developments. The water regimes and water quality experienced by groundwater dependent ecosystems are changing due to consumptive uses and to other land use and management factors. Collectively, anthropogenic changes in groundwater regime pose a significant, but largely unknown threat to groundwater dependent ecosystems. That threat will be maintained and may ultimately be realised unless specific actions are taken to provide these ecosystems with appropriate water regimes.
Like other forms of natural resource management, groundwater resource management is required to operate according to the principles of Ecologically Sustainable Development. To do so, groundwater resources must be managed in ways that are consistent with the principles of conservation of biological diversity, namely:
- conservation of biodiversity should take place in situ;
- action to conserve biodiversity must not be postponed in the absence of full knowledge;
- the establishment of a comprehensive, representative and adequate system of ecologically viable protected areas;
- sympathetic management of other landscapes, including those in which agricultural and other resource production systems operate.
(after Government of Australia 1996)
If groundwater resource management is to be consistent with these principles, then allocation processes must consider the environmental needs of dependent ecosystems. Where appropriate they must also ensure that water is provided to meet the needs of key ecological functions in groundwater dependent ecosystems.
This report deals with the three main stages in the process of allocating groundwater to meet the needs of dependent ecosystems. The report also proposes a policy framework for this process that could be adopted at national and state levels.