Guide to the proposed Basin Plan Volume 2 Technical background Guide to the proposed Basin Plan Volume 2 Technical background | Part I Published by the Murray–Darling Basin Authority Postal address GPO Box 3001, Canberra ACT 2601 Telephone 1800 230 067 Facsimile (02) 6230 7579 Email [email protected] Internet www.mdba.gov.au MDBA publication no. 61/10 ISBN (print) 978-1-921557-74-3 ISBN (online) 978-1-921557-75-0 This report may be cited as: Murray–Darling Basin Authority 2010, Guide to the proposed Basin Plan: Technical background, Murray–Darling Basin Authority, Canberra. © Copyright Commonwealth of Australia 2010 This work is copyright. With the exception of photographs, any logo or emblem, and any trademarks, the work may be stored, retrieved and reproduced in whole or in part, provided that it is not sold or used in any way for commercial benefit, and that the source and author of any material used is acknowledged. Apart from any use permitted under the Copyright Act 1968 (Cwlth) or above, no part of this work may be reproduced by any process without prior written permission from the Commonwealth. Requests and inquiries concerning reproduction and rights should be addressed to the Commonwealth Copyright Administration, Attorney-General’s Department, National Circuit, Barton ACT 2600 or posted at www.ag.gov.au/cca. Disclaimer This document has been prepared by the Chief Executive of the Murray–Darling Basin Authority to inform public discussion about the proposed Basin Plan. The material in this document has not been endorsed by the Murray–Darling Basin Authority. To the extent that there is a material inconsistency between this document and the Guide to the proposed Basin Plan: overview, then the policy intent in the Guide to the proposed Basin Plan: overview prevails. The opinions, comments and analysis (including those of third parties) expressed in this document are for consultation purposes only. This document does not indicate the Murray–Darling Basin Authority’s commitment to undertake or implement a particular course of action, and should not be relied upon in relation to any particular action or decision taken. Users should note that developments in Commonwealth policy, input from consultation and other circumstances may result in changes to the approaches set out in this document. Descriptive information about the Basin, regions within it, and their history and development has been collated primarily from previously published sources. The Murray–Darling Basin Authority makes no warranty as to the accuracy or completeness of this information. Material in this volume is based on the latest information available at the time of writing. Cover image: Junction of the Murray and the Darling rivers at Wentworth, New South Wales iii Volumes of the Guide to the proposed Basin Plan TheGuide to the proposed Basin Plan comprises a series of publications which are being prepared to inform consideration and discussion of the draft Murray–Darling Basin Plan. While the Basin Plan itself will be a legislative instrument, the Guide to the proposed Basin Plan provides information on the background and process of developing all the different parts of the proposed plan. This information includes: • a summary of the history and current state of Basin water resources • the factors driving change in use and management of water resources • the proposed new arrangements under the Basin Plan, and their impacts • implementation of the Basin Plan. The volumes of the Guide to the proposed Basin Plan are: 1 Overview 2 Technical background 3 Barwon–Darling region 4 Border Rivers region 5 Campaspe region 6 Condamine–Balonne region 7 Eastern Mount Lofty Ranges region 8 Goulburn–Broken region 9 Gwydir region 10 Lachlan region 11 Loddon region 12 Lower Darling region 13 Macquarie–Castlereagh region 14 Moonie region 15 Murray region 16 Murrumbidgee region 17 Namoi region 18 Ovens region 19 Paroo region 20 Warrego region 21 Wimmera–Avoca region Acknowledgement In preparing this volume of the Guide to the proposed Basin Plan, the Chief Executive of the Murray–Darling Basin Authority has drawn on the knowledge and support of many individuals, organisations and communities. Some of these have been involved in developing underpinning information and knowledge, assisting with the development of policy positions, or technical scrutiny of early drafts. On behalf of the authority, the Chief Executive would like to thank everyone for their assistance, including the community members who participated in workshops and forums and provided feedback and comments (see Acknowledgements at the back of this volume). iv Guide to the proposed Basin Plan Technical background Part I Table of contents 1. Introduction ..........................................................................................1 1.1 Purpose of the Guide to the proposed Basin Plan ...............................2 1.2 What’s covered in this volume ..............................................................2 1.3 Role of the Commonwealth ...................................................................3 Murray–Darling Basin Authority ......................................................3 Commonwealth Water Minister .......................................................4 Commonwealth Environmental Water Holder .................................4 Australian Competition and Consumer Commission ......................5 National Water Commission ............................................................5 Bureau of Meteorology ....................................................................5 1.4 Role of the Basin states .......................................................................6 1.5 What’s next ............................................................................................7 2. The Murray–Darling Basin ..................................................................9 2.1 A description of the Basin ...................................................................10 Historical setting ............................................................................16 Harnessing the water resources ...................................................18 Major infrastructure .......................................................................19 2.2 The Basin economy ............................................................................21 Agriculture......................................................................................22 Mining ............................................................................................24 General industry ............................................................................24 Recreational use ............................................................................25 Household use ...............................................................................25 2.3 Aboriginal interests in Basin water resources .....................................25 2.4 The social fabric of the Basin ..............................................................26 Employment ...................................................................................27 Farmers .........................................................................................27 Income ...........................................................................................28 2.5 Basin environment ...............................................................................28 2.6 Basin water resources .........................................................................32 Rainfall ...........................................................................................32 Surface-water resources ...............................................................32 Groundwater resources ................................................................40 Connectivity ..................................................................................42 Water quality .................................................................................45 Water trade ....................................................................................48 2.7 Management of Basin water resources ..............................................50 Before Federation ..........................................................................50 Federation ......................................................................................51 River Murray Waters Agreement ...................................................51 Murray–Darling Basin Agreement ................................................53 Water management today .............................................................55 3. The proposed Basin Plan ..................................................................65 3.1 Management objectives and outcomes .............................................67 Achieving the plan’s management objectives and outcomes .......68 3.2 Water resource plan areas ..................................................................69 3.3 Risks to the Basin’s water resources .................................................75 Risk assessment approach ..........................................................75 Risks and their contributing factors ...............................................76 Contents v 3.4 Risk management ..............................................................................78 Future risk assessment .................................................................80 3.5 The evidence base .............................................................................80