HUME AND DARTMOUTH DAMS OPERATIONS REVIEW REFERENCE PANEL Hume and Dartmouth Dams Operations Review Final Report MAY 1999 HUME AND DARTMOUTH DAMS OPERATIONS REVIEW REFERENCE PANEL Hume and Dartmouth Dams Operations Review Reference Panel FINAL REPORT AND RECOMMENDATIONS SUBMITTED TO THE MURRAY-DARLING BASIN COMMISSION MAY 1999 i HUME AND DARTMOUTH DAMS OPERATIONS REVIEW REFERENCE PANEL Published by Hume and Dartmouth Dams Operations Review Reference Panel Postal Address: c/- MDBC, GPO Box 409, Canberra ACT 2601 Office location: c/- Murray-Darling Basin Commission, 2nd Floor, 7 Moore Street, Canberra City, Australian Capital Territory. Telephone: (02) 6279 0100; international + 61 2 6279 0100 Facsimile: (02) 6248 8053; international + 61 2 6248 8053 E-mail [email protected] Website http://www.mdbc.gov.au Map on cover: © Commonwealth of Australia 1985 Series R754, 8225-1 ALBURY, VICTORIA AND NEW SOUTH WALES, Edition 1-AAS, Royal Australian Survey Corps 1985, reproduced with the kind permission of the Director of Strategic Military and Geographic Information. Remainder of Publication © Copyright Murray-Darling Basin Commission 1999. This document may be reproduced in whole or in part, provided that the information in it is not sold for commercial purposes and its source is acknowledged. Dissemination and discussion of the document is encouraged. For further copies and assistance contact the Reference Panel at the above address. ISBN 1 875209 77 8 DISCLAIMER This document is the work of a fully independent Panel, reporting to the Murray-Darling Basin Commission. The report has not been influenced or directed by the Commission, nor at the time of printing has the Commission considered or adopted its recommendations. ii HUME AND DARTMOUTH DAMS OPERATIONS REVIEW FOREWORD This report represents a significant achievement Environmental Sustainability. The Panel listened in the development of a consensus between to all views and spent time visiting areas of parties advocating what are, on the surface, concern, with itineraries and presentations irreconcilable objectives for the management of arranged entirely by the local interests. The a precious and finite resource – the waters of Reference Panel, in fact, drove and shaped the the Upper Murray system. entire review and, I think it fair to say, has in In early 1997, in response to the concerns of the process created an ownership of the issues. floodplain landholders below its two major The Panel firmly believes that any process of headworks, the Murray-Darling Basin natural resource management that involves Commission began a review of the operations of tradeoffs will never succeed properly unless the Hume and Dartmouth Dams. At that time, few powers-that-be recognise and support such were confident that a consensus would be community ownership. In this case, the achieved within the Reference Panel that had Commission commendably adopted a hands-off been created as part of the review process. stance, provided adequate resources, and Two vital factors however were at play – allowed the Panel the time it needed to feel Information and Inclusion. comfortable with the developing outcomes. Information – The Panel attempted wherever So, what were these outcomes? possible to describe situations by means of factual First, a word of warning. The operations of and, preferably, quantified information. This Hume and Dartmouth are complex and required the time-consuming creation of a daily sophisticated. Also, intuition is not always a time-step river flows model, the quantification of reliable indicator of operational outcomes. What economic outcomes, and the development of follows is a greatly simplified set of the Panel’s indicators to attempt to predict the major findings. To read this in isolation would be environmental outcomes. The largely successful potentially misleading. The reader is encouraged aim was to minimise argument about how ‘good’ to read the full Final Report and its companion or ‘bad’ a particular scenario was, by having Options Paper to understand the many factors at numerical measurements of the outcomes. play and their complex inter-actions. Because no reliable formulas yet exist which In the reach of the Mitta Mitta River below describe ecosystem response to river flow Dartmouth Dam, it was found that the present changes, the Panel found it necessary to develop harmony and pre-release rules are generally a comprehensive set of flow parameters which appropriate. The Panel’s work has shown could be viewed as surrogates for environmental however that there is scope to reduce the outcomes. In general it was agreed that flow environmental and economic impacts of patterns which more nearly represented natural Dartmouth Dam by a modified and more patterns were the most desirable. variable flow regime with no discernible impacts The Commission also helped by being entirely on consumptive users. open and thus created a growing trust in the As elsewhere along the rivers, the Panel process. The Panel was given access to all relevant found that a more comprehensive approach to documents and information, including some not whole-of-system management would produce yet formally considered by the Commission. improved outcomes. It therefore strongly Inclusion – The spread of representation on believes that an integrated program of waterway the Panel, and its determination to ensure that and floodplain management is required for the the Valley community could participate in the Mitta Mitta. It also proposes that the costs and debate, slowly but surely created a growing benefits of a variable level offtake at Dartmouth understanding and mutual respect between the be investigated. parties at the corners of a triangle of tensions – In considering the River Murray below Hume Water Use, Floodplain Land-use and Dam, an early conclusion of the Panel was that HUME AND DARTMOUTH DAMS OPERATIONS REVIEW iii HUME AND DARTMOUTH DAMS OPERATIONS REVIEW REFERENCE PANEL flood easements should be negotiated with addressing waterway and floodplain management landholders as a principal means of addressing requires funding and immediate initiation. adverse effects of flooding at the peak regulated A common issue raised along the whole river flow level of 25 000 megalitres/day. was a perception of inadequate communications Reinstating some of the natural variability of from the Commission about water management, flow is an important objective in the Hume to with a particular emphasis on flood seasons. Yarrawonga reach and may be possible with few Interestingly, it was found that floodplain trade-offs during the majority of the year. community concerns and perceptions did not Currently there is little room for movement always reflect the reality of actual dam operations during the peak irrigation season when the which were generally near optimum. What existing nominal channel capacity already seemed to be missing was information and restricts operational flexibility. The Panel consultation. The Panel therefore believes that however found that there is scope for increased structured and regular liaison is required between rates of pre-releases and environmental releases River Murray Water and interested community through negotiation with landholders for groups. This should be accompanied by ongoing, purchase of limited, special purpose easements. real-time liaison and consultation with Mitta After comprehensive modelling of multiple Mitta landholders, Hume to Yarrawonga scenarios, an appropriate environmental flow landholders, and with peak irrigator groups. regime below Hume Dam (a managed form of Finally, in keeping with its strongly held translucency of around 30% is shown to have views on the need for community involvement considerable promise) has been recommended to and ownership of natural resource management, improve river health and to minimise the the Panel is firmly of the view that development adverse economic impacts of regulated flows, of environmental flow options for the whole particularly to floodplain landholders. river should include a community-based steering Also important are the operational scenarios or reference committee. for which the Panel recommends no further All Panel members have shown dedication, consideration. For instance, the popular notion tolerance and commitment throughout. I thank of ‘air-space’ operations is shown to be very them for this and congratulate them on a real costly in water terms, whereas other options are contribution to the future of the Murray Valley. shown to have a better mix of outcomes. In this I have pleasure in commending this report to case, an environmental flow regime modelled the Murray-Darling Basin Commission. was shown to produce equivalent benefits for floodplain owners, but with a lower cost to consumptive water users, plus of course a regime more favourable to river health. The existence of the State border has mitigated against the much needed BRIAN HAISMAN whole-of-system approach between Hume and Chair, Yarrawonga. The Panel believes that a Operations Review Reference Panel ‘no-borders’ integrated River Management Plan May 1999 iv HUME AND DARTMOUTH DAMS OPERATIONS REVIEW Contents 1 Background 1 1.1 Introduction 1 1.2 Responses to Options Paper 1 1.3 Finalisation of issues raised in Options Paper 1 1.4 Issues not covered in Options Paper 1 1.4.1 Economic modelling 1 1.4.2 Effects on flows to South Australia 2 1.5 Corrections to Options paper 2 1.6 Cost Sharing 2 2 Conclusions and Recommendations 3 2.1 Dartmouth – Hume reach of Mitta Mitta