Environmental Water Requirements to Maintain Wetlands of National and International Importance
Technical Report Number 1
Jenny Davis, Ray Froend, David Hamilton, Pierre Horwitz, Arthur McComb, Carolyn Oldham and Deb Thomas
Environment Australia, 2001
ISBN 0 642547688
- Environmental Water Requirements to Maintain Wetlands of National and International Importance (PDF - 995 KB)
About the report
This project is a component of the National River Health Program, which aims to protect Australia's water resources. It is an adjunct to the research program undertaken by States and Territories and funded by Environment Australia under the Environmental Flows Initiative. This program lies within the policy context of the Council of Australian Governments Water Reform Framework. Important principles directing the Environmental Flows Initiative include:
- environmental flow decisions should be based on sound scientific knowledge
- water resource developments should be ecologically sustainable
- allocations should be reviewed five years after they are allocated
- allocations should be made to allow adjustment of allocations as necessary
- methods for determining environmental flows (for given broad geographic areas or types of environment) should be as consistent as possible throughout the country.
This project, Environmental Water Requirements to Maintain Wetlands of National and International Importance, was concerned with the determination of water requirements for important wetlands with water regimes that are threatened by human impacts. The objectives of this project were:
- to identify those wetlands in Australia of international and national importance that are threatened by current or future changes to flow regime
- to develop a method for determination of appropriate environmental flows that will protect these wetlands against decline in their ecological character
- to identify the practical limitations and opportunities available for implementation of environmental flows to these systems.
For the purposes of this project, wetlands are defined as lentic waters lacking direct surface connection with the sea. Lakes (including seasonal, ephemeral and permanent), marshes, ponds, forested and shrub swamps, inland deltas, peatlands, bogs, springs, rock pools, and subterranean karst wetlands are covered. Wetland aggregations which include wetlands belonging to these categories have been covered by this project. Wetlands listed as Ramsar sites have been identified as being of international importance and have met one or more criteria including representativeness, uniqueness, or significant flora or fauna. In addition, there are specific criteria associated with waterfowl (ANCA, 1996). The Directory of Important Wetlands (ANCA, 1996) lists wetlands of national and international significance. A wetland may be deemed nationally significant on the basis of
- being a good regional example of a wetland type,
- its ecological or hydrological role, its role as habitat for fauna at vulnerable life stages,
- its provision of drought refuge for fauna,
- supporting 1% or more of the national population of an animal or plant taxon,
- supporting nationally vulnerable or endangered taxa or communities, or
- its cultural or historic significance (ANCA, 1996).
This report is presented in five chapters. The first identifies Australian wetlands of international and national significance threatened by changes to water regime and presents a summary of threats on a regional basis (Chapter 1). This is followed by a review of the literature on environmental water allocations for wetlands (Chapter 2). The history of water allocations to the Macquarie Marshes (NSW), the Gwydir wetlands (NSW), Kerang Lakes (Victoria), wetlands of the Lachlan River Valley, Lakes Merreti and Woolpolool of the Chowilla floodplains (SA), the Barmah-Millewa Forests (Victoria/NSW), wetlands of the Gnangara Mound (WA) and Twin Swamps (WA) were examined. In addition, the effects of measures to conserve the water resource of the Great Artesian Basin on mound spring wetlands of this region were examined. This review is followed by a comparison and analysis of various methodologies used for the determination of environmental water allocations for wetlands (Chapter 3). From this a framework was developed (Chapter 4). Finally, opportunities and limitations for environmental water allocations for wetlands were identified (Chapter 5).