MURRAY-DARLING BASIN COMMISSION 0 100 200 300 400 500 600 700 Narran Ecosystem Project The response of a terminal wetland system to variable wetting and drying. Final report to the Murray-Darling Basin Commission MURRAY-DARLING BASIN COMMISSION 0 100 200 300 400 500 600 700 Narran Ecosystem Project The response of a terminal wetland system to variable wetting and drying. Final report to the Murray-Darling Basin Commission Project Leader Professor Martin Thoms Science Team Dr Samantha Capon, Dr Cassandra James, Dr Mark Padgham, Dr Scott Rayburg September 2007 Published by the Murray-Darling Basin Commission Postal address: GPO Box 409, Canberra ACT 2601 Office location: 51 Allara Street, Canberra City Australian Capital Territory Telephone: (02) 6279 0100, international + 61 2 6279 0100 Facsimile: (02) 6248 8053, international + 61 2 6248 8053 Email: [email protected] Internet: http://www.mdbc.gov.au For further information contact the Murray-Darling Basin Commission office on (02) 6279 0100 This report may be cited as: The Narran Ecosystem Project: the response of a terminal wetland system to variable wetting and drying. Final report to the Murray-Darling Basin Commission. MDBC Publication No. 40/08 ISBN 978 1 921257 80 3 © Murray-Darling Basin Commission /eWater CRC 2008 This work is copyright. 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To the extent permitted by law, the copyright holders (including their employees and consultants) exclude all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this report (in part or whole) and any information or material contained in it. Cover photograph��������������������������: Sunset in the colony, by �.���������� Brandis. COntents 1. Executive Summary ....................................................................................1 6.3 Ecological Responses ............................................................ 44 6.3.1 Aquatic ecology .............................................................. 44 2. Preamble ...................................................................................................................5 6.3.2 Vegetation ............................................................................. 48 3. Overview of Study Area ..........................................................................7 6.3.3 Waterbirds ........................................................................... 57 4. Overview of Project .....................................................................................9 6.3.3.1 Waterbird breeding in the Narran Ecosystem ............................... 57 5. Key Activities ....................................................................................................12 6.3.3.2 Landscape scale influences 5.1 Overview ................................................................................................. 12 on waterbirds in the Narran Ecosystem ...................................................... 58 5.2 Physical template ........................................................................ 12 6.4 Conceptual Model ....................................................................... 61 5.2.1 Regional context ........................................................... 12 6.4.1 Physiacl factors ............................................................. 63 5.2.2 Topography .......................................................................... 13 6.4.2 Hydrological factors ................................................. 64 5.2.3 Soils ............................................................................................. 13 6.4.3 Ecological factors ........................................................ 65 5.2.4 Channel network.......................................................... 13 6.4.4 Interactions among physical, 5.2.5 Environmental history ........................................... 15 hydrological and ecological factors ....... 67 5.3 Hydrological drivers ................................................................. 16 6.5 Knowledge Exchange.............................................................. 68 5.3.1 Climate..................................................................................... 16 6.5.1 Community and Industry 5.3.2 Hydrology .............................................................................. 16 fact sheets............................................................................ 68 5.4 Ecological responses .............................................................. 18 6.5.2 Oral History ......................................................................... 68 5.4.1 Aquatic ecology .............................................................. 18 6.5.3 Newsletters ........................................................................ 69 5.4.2 Vegetation ............................................................................. 20 6.5.4 Scientific papers ........................................................... 69 5.4.3 Waterbirds ........................................................................... 23 6.5.5 Community presentations ................................ 70 5.5 Knowledge Exchange.............................................................. 23 6.5.6 Industry presentations .......................................... 71 6.5.7 Scientific presentations and 6. Key Findings .....................................................................................................24 conferences ........................................................................ 71 6.1 Physical template ........................................................................ 24 6.5.8 Media .......................................................................................... 73 6.1.1 Regional context ........................................................... 24 Appendix 1: Groundcover species list ....................................75 6.1.2 Topography .......................................................................... 25 6.1.3 Soils ............................................................................................. 26 Appendix 2: Tree species list ..............................................................77 6.1.4 Channel network.......................................................... 27 Appendix 3: Methodology and Management 6.1.5 Environmental history ........................................... 27 Implications ...........................................................................78 6.2 Hydrological drivers ................................................................. 30 References ............................................................................................................... 106 6.2.1 Climate..................................................................................... 30 6.2.2 Hydrology .............................................................................. 30 6.2.3 Hydraulic and hydrologic models ............ 38 iii 1. ExecutiveSummary 1. ExecutivE Summary Background to manage these types of systems have not been based on sound scientific data and information Large floodplain ecosystems are a feature of to date. Questions remain concerning how much Australia’s dryland rivers. They are associated water these ecosystem require in order to maintain with numerous wetlands, lakes and small creeks and conserve their ecological integrity. The Lower that dissect the extensive floodplain surfaces. The Balonne region has been subjected to large water Narran Ecosystem, located in northwest New South resource developments. Most water resource Wales, is a key refugia for many aquatic and water- development in the Condamine-Balonne Catchment dependent terrestrial plants and animals in an has occurred since the advent of irrigated agriculture otherwise dry landscape. In June 1999, the Narran in the 1960s. There are three main irrigation Lakes Nature Reserve, which occupies the northern developments within the Condamine-Balonne section of the Narran Ecosystem was inscribed on catchment; the St George Irrigation Area located on the List of Wetlands of International Importance the Lower Balonne Floodplain is the largest. There under the Convention on Wetlands of International are also four significant public water storages in Importance (Ramsar). It is also an integral part the catchment, which service irrigation, agricultural of three international migratory bird agreements: and domestic supply. These being Leslie Dam the Chinese Australian Migratory Bird Agreement (106 250 Ml); Chinchilla Weir (9800 Ml); Beardmore (CAMBA), the Japanese Australian Migratory Bird Dam (81 800 Ml) and Jack Taylor Weir (10 100 Ml). Agreement (JAMBA) and the Republic