......................................................................................................................................... 10 MANAGERS’ SUMMARY ................................................................................................................ 12 1. Purpose and scope of this report ............................................................................................ 12 2. Barmah Forest in its Regional and Historical setting............................................................. 12 3. Values from Barmah Forest ................................................................................................... 14 4. Objectives for environmental water use................................................................................. 18 5. Classification of Floodplain Vegetation Communities .......................................................... 19 6. Floodplain Vegetation Responses to Water Regime, Grazing and Fire................................. 19 6.1 River flows and floodplain inundation .......................................................................................... 19 6.2 Evaluating the vegetation objectives in management plans .......................................................... 20 6.3 Plants and Water Regime.............................................................................................................. 20 6.3.1 The scientific basis for water-related objectives................................................................... 21 6.4. The effects of grazing and fire....................................................................................................... 22 7. Waterbird Responses to Water Regimes................................................................................. 22 7.1. Evaluating waterbird management objectives .............................................................................. 22 7.2. The Scientific Basis for Waterbird Management........................................................................... 23 8. Evaluation of the 1998 and 2000 Environmental Water Allocations..................................... 25 9. Water Management Options ................................................................................................... 27 9.1. Managing Water Within Barmah Forest....................................................................................... 27 9.1.1 Improving the precision of water management .................................................................... 27 9.1.2 Trade-offs in the allocation of water..................................................................................... 27 9.1.3 Getting water to higher elevations ........................................................................................ 28 9.1.4 Groundwater ......................................................................................................................... 28 9.1.5 Water Quality ....................................................................................................................... 28 9.1.6 Erosion rate........................................................................................................................... 28 9.2. Availability of water and threats to supply.................................................................................... 28 9.2.1 Options for getting water to Barmah Forest and managing and adapting to adverse river flows ............................................................................................................................................... 29 10. Conclusions and Recommendations ................................................................................... 30 10.1 Values.......................................................................................................................................... 30 10.2. Objectives for Environmental Water Use.................................................................................... 30 10.3 Classification of floodplain vegetation communities................................................................... 31 10.4 Floodplain Vegetation Responses to Water Regime, Grazing and Fire...................................... 31 10.4.1 Objectives for Vegetation Management ............................................................................. 31 10.4.2 Improving the Vegetation Management and Hydrological Knowledge Base..................... 31 10.5 Waterbird Responses to Water Regimes...................................................................................... 32 10.5.1 Objectives and Water Regimes........................................................................................... 32 10.5.2 Improving The Waterbird Management Knowledge Base ................................................. 32 10.6 Evaluation of the 1998 and 2000 Environmental Water Allocations .......................................... 33 10.7 Water management options......................................................................................................... 33 10.7.1 Allocating Water Within Barmah Forest ............................................................................ 33 10.7.2 Getting water to Barmah-Millewa Forest and Managing Unseasonal Flows ..................... 34 10.8 Water and the Future of Barmah Forest ..................................................................................... 34 Barmah Forest Review May 2006 Page 3 ACKNOWLEDGEMENTS .................................................................................................................. 35 1. PURPOSE AND SCOPE OF THIS REPORT............................................................................ 36 2. BARMAH FOREST IN ITS REGIONAL AND HISTORICAL SETTING.............................. 40 2.1 Location ............................................................................................................................... 40 2.2 Drainage ............................................................................................................................... 41 2.3 Vegetation ............................................................................................................................ 41 2.4 Surface Hydrology ............................................................................................................... 42 2.5 Groundwater......................................................................................................................... 42 3. VALUES FROM BARMAH FOREST ...................................................................................... 46 3.1 Use Values ........................................................................................................................... 50 3.1.1 Direct use Values ....................................................................................................................... 51 Marketed Outputs ........................................................................................................................... 51 Un-marketed Outputs ..................................................................................................................... 52 3.1.2 External Ecological Function Values......................................................................................... 53 3.2 Non-use Values .................................................................................................................... 54 3.2.1 Existence Values......................................................................................................................... 54 3.2.2 Option Values............................................................................................................................. 54 3.2.3 Bequest Values ........................................................................................................................... 55 3.3 Assessment of the Values at Different Scales...................................................................... 55 3.4 Key gaps in value assessments............................................................................................. 55 4. OBJECTIVES FOR ENVIRONMENTAL WATER USE ......................................................... 56 4.1 Purpose and background ...................................................................................................... 56 4.3 Evaluation of current objectives for Barmah Forest. ........................................................... 58 4.3.1 Protect the ‘ecological character’ of the floodplain, as required under the Ramsar Convention. ............................................................................................................................... 58 4.3.2 Enhance the ecological functions and diversity of the floodplain by re-instating a more natural flood regime ................................................................................................................. 59 4.3.3 Enhance breeding and recruitment of indigenous floodplain fauna and germination and regeneration of indigenous flora............................................................................................... 59 4.3.4 Provide suitable habitat conditions for indigenous flora and fauna.......................................... 59 4.3.5 Ensure that all natural, flow related ecological functions can occur ........................................ 59 4.3.6 Protect and restore Moira Grass plains..................................................................................... 60 4.3.7 Ensure breeding success of colonial water birds. ...................................................................... 60 4.3.8 ‘Overall ecological objective’ for the Barmah-Millewa wetland system ................................... 60 4.3 The need for a new set of objectives..................................................................................