Bob Douglas Director, Water Policy Coordination Murray-Darling Basin Commission La Trobe University 29 June 2006 Reaching interstate consensus - Recent challenges and lessons from the MDBC

Australia’s Murray-Darling Basin 1.06 million sq. km 15% land mass 6.1% of Australia’s total run off major river system 2 million people 2 capital cities

Australia’s Murray-Darling Basin highly modified environment extremes in climatic variability environmentally significant economically and socially important

Flows are small RiverAverage Annual Flow (GL) (approx) Amazon (Sth America) 5,518,800 Yangtze (China) 1,014,700 Yenisey/ Selenga (Russia) 567,700 Ganga (India) 525,000 Mississippi/Missouri (USA) 405,100 Nile (Africa) 88,500 Hwang Ho (China) 51,100 Murray 14,700

Ratio of maximum annual flow to minimum annual flow for selected rivers COUNTRYRIVERRATIO BETWEEN THE MAXIMUM and the MINIMUM ANNUAL FLOWS BRAZILAMAZON1.3 SWITZERLANDRHINE1.9 CHINAYANGTZE2.0 SUDANWHITE NILE2.4 USAPOTOMAC3.9 SOUTH AFRICAORANGE16.9 AUSTRALIAMURRAY15.5 AUSTRALIAHUNTER54.3 AUSTRALIADARLING4705.2

MDB rainfall variability (480mm annual average) River Murray system showing extended drought periods

Environmentally significant large ecological range – alpine to rainforest to arid numerous reserves, national parks 16 RAMSAR sites world heritage convention listings internationally important biosphere reserves breeding grounds for migratory birds at least 35 endangered birds at least 16 endangered mammals

Economic importance 40% of Australian agriculture –approx $14 billion 70% of irrigated agriculture –approx $7 billion Tourism Manufacturing (food processing) Mining Rural Communities

Highly regulated river system $2 billion infrastructure resource sharing/ allocations high levels of climatic variability water flows impacts of river regulation

Murray-Darling Basin Commission Murray-Darling Basin Agreement 6 governments working together Charter "to promote and co-ordinate effective planning and management for the equitable efficient and sustainable use of the water, land and other environmental resources of the Murray-Darling Basin."

SIX GOVERNMENTS Aust Gov. NSW Vic SA Qld ACT MURRAY-DARLING BASIN MINISTERIAL COUNCIL Community Advisory Committee MDBC Office MURRAY-DARLING BASIN COMMISSION River Murray Water Committee Living Murray Committee Natural Resources Management Committee Commission Strategy Committee

Major Challenges for the MDBC coordination between 6 govts sharing the water –highly regulated system –5 jurisdictions –industries, environment, communities managing as one catchment –synergies between strategies –implementing The Living Murray major risks to shared water resources

Growth of surface water use in Murray-Darling Basin The Cap

River Murray Environmental Flows

Risks to shared water resources number of risk factors may reduce annual surface flows in the MDB by about 20% over the next 20 years. also impact on –flow regime –water quality and –water security impact is uncertain estimated reduction in water volume between 2,500GL and 5,500 GL in 20 years (average annual flow ~ 14,700 GL)

Risks to shared water resources climate change growth in dams increased groundwater use reduction in return flows from irrigation reforestation/ land use change bushfires

Climate change estimated largest and most likely reduction in flow increase the other risks potentially reduce stream flow by –1,100 GL in 10 years (5% of annual flow) –3,300 GL in 50 years (15% of annual flow) Predicted regional differences in percentage reductions in annual stream flow. Dark red indicates greatest reductions. (Source: Jones and Brooke).

Growth in Dams impact on water volume second to climate change evidence suggesting number and size of farm dams increased significantly in last 10 years estimated total streamflow reduction by – 250 to 3,000 GL / year in 20 years – 400 to 4,000 GL/ year in 50 years future impact depends on effectiveness of legislation or policies

Groundwater systems constitutes 10-15% of water used significant growth in groundwater use connectivity may threaten surface water availability consistency in defining sustainable yield Source: Groundwater Status Report

Reduction in return flows in irrigation water diverted for irrigation losses through leakage and evaporation flows back to river and groundwater systems if not used more efficient water use –reduced flows back to stream –could increase salinity

Source: BRS Reforestation/ land use change plantations potentially reduce water yield in a catchment productive forestry areas tend to have water yield impacts reduction in water flow depends on plantations location and size Increase of plantation forestry in Australia (current and trajectory) towards the 2020 Vision.

Bushfires bushfires in 2003 affected high rainfall areas in MDB catchment severe fires have long term effects affect water quality and reduce surface and groundwater levels climate change ↑ frequency and intensity of dry periods = ↑ bushfires Variation in run-off from Mountain Ash forests. (source: Kuczera)

Estimated impact Estimated impact of the six risks on Murray-Darling Basin surface water by Darkest colours show most likely impact (Source: MDBC)

Shared water resources Water shared between jurisdictions (includes both groundwater and surface water)

Framework need to consider the risks together in an integrated and adaptive way understand the interrelationships of the various activities and processes and effect on water quantity and quality in the Basin working with the jurisdictions to address the risks requires –collaboration –building on and enhancing the actions already being taken by individual jurisdictions –identifying where value can be added by a more integrated and collaborative approach –ensuring there is adequate commitment and resources within the jurisdictions

Michael Bell

2 Qld 1 Independent President + 2 NSW 2 Federal 2 Vic 2 SA 1 ACT

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