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14th Riversymposium, keynote presentation from Prof Barry Hart (2011)


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The Basin Plan striking the right balance, Professor Barry Hart, Muray-Darling Basin Authority

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14th Riversymposium, keynote presentation from Prof Barry Hart (2011)

  1. 1. The Basin Plan —striking the right balance Professor Barry Hart
  2. 2. Where is the Murray–Darling Basin? Large system  1 million km2  1/7 area of Australia  Contains Australia’s three longest rivers – Murray — 2,380 km – Darling — 1,480 km – Murrumbidgee — 1,490 km  23 river basins  Major climate differences (north to south)  Murray — highly regulated Darling — unregulated
  3. 3. Hydrology of the Basin Northern Basin Southern Basin
  4. 4. Basin Plan — why the need?Significant changes to hydrology less flooding (overbank flows) changes to seasonal flow regimesOverallocation of water resources particularly severe in southern BasinDegradation of the environment river red gums dying fish populations reduced waterbird number reduced algal blooms water quality degradation — salinity Murray mouth closedIncreased threat to agricultural production
  5. 5. Balancing the equation Without development Current Interceptions 42% consumptive Environment Diversions 60% Environment 58% environment Flow to sea 40% Flow to the sea Murray — 58%, 42% Darling — 28%, 72%
  6. 6. Basin Plan — purposeObjective to develop and implement an integrated water resource plan for the whole BasinBasin Plan seeks to rebalance the system more water for the environment minimise the impacts on irrigators and local communitiesMDBA’s task set the bounds with sustainable diversion limits (SDLs) and work with the states and local communities to implementMDBA only has powers to do part of the reform but ……
  7. 7. The Basin PlanThe Basin Plan must include: sustainable diversion limits (SDLs) water resource plan accreditation Environmental Watering Plan Water Quality & Salinity Management Plan water trading rules monitoring and evaluation program
  8. 8. What are we aiming to achieve?A healthy working Basin with: critical drinking water needs met rivers connected to creeks, billabongs and floodplains healthy ecosystems supporting a wide variety of plants and animals sufficient flows to flush nutrients and salt through the system sustainable growth in food and fibre production long-term confidence for businesses and communities ‘fit for purpose’ water quality a free market for trading water
  9. 9. What we wish to achieve
  10. 10. Four-stage process Information Information feedback formal submission Adoption The The draft The Basin Initial Guide Basin Plan Plan implementation 2010 2011 2012 2019
  11. 11. The task Healthy riversSocial and economic Balance | Judgement Environmental science• Macro-economic models • Salt and nutrient export target• Parliamentary enquiries • End-of-system flows• Cost-benefit analysis • 106 hydrologic indicator sites:• Local impacts study - key ecosystem functions - key environmental assets Environmentally sustainable level of take System constraints • River operations • Policy • Physical
  12. 12. Decision-making process Environment Implications (science + judgements) • social and economic • define the environment • environmental we want to protect • define what we want Balance it to be (objectives) • determine how much water we need to achieve this — the environmental water requirement (EWR) ↔ Environmentally Sustainable more than sustainable level diversion just a of take (ESLT) limit (SDL) volume
  13. 13. Defining the environment Largely done in the Water Act 2007 (Cwlth) Key environmental assets – wetlands, floodplain forests, rivers, estuary (Coorong) – largely specific areas, locations – judgements required to define which are ‘key’ assets and how much water they need Key ecosystem functions – largely ecological processes – primary production, fish migration, triggers for breeding, material transport – judgements required in relating functions to flows Ecosystem services – not considered yet
  14. 14. How much water is needed?Key environmental assets Too many to assess — over 2000 identified 18 assets selected as hydrologic indicator sites These sites are: – hydrologically representative – have a good information base Most sites selected are wetlands or floodplain forests that require high flows largely through overbank flows High flows make the largest contribution to volume and therefore the largest influence Gwydir Wetlands, north-west of Moree, New South Wales on ESLT Photograph Ray Dawson
  15. 15. Hydrologic indicator sites (assets) Lower Balonne River Floodplain System Narran Lakes Booligal Wetlands Lachlan Swamps Great Cumbung Swamp Lower Murrumbidgee Wetlands Lower Darling River System Gwydir Wetlands Hattah Lakes Macquarie Marshes Riverland – Chowilla Floodplain Mid Murrumbidgee Wetlands Coorong, Lower Lakes and Murray MouthWimmera River Terminal Wetlands Barmah Millewa Forest Edward Wakool River System Lower Goulburn River Floodplain Gunbower Koondrook Perricoota Forests
  16. 16. How much water is needed?Without development
  17. 17. How much water is needed?Baseline
  18. 18. How much water is needed?SDL scenario
  19. 19. Balancing Key 18 hydrologicenvironmental indicator sites Socio– assets (assets) economic assessment Environmental water Sustainable requirements diversion limits Key 88 hydrologic ecological indicator sites System functions (functions) constraints
  20. 20. Environmental waterWithin each catchment, two components identified: local requirements to water the assets and functions in that catchment downstream requirement to water assets and functions in lower parts of the BasinExample — Goulburn catchment local for the river channel and lower Goulburn Floodplain downstream — contribution to River Murray assets and functions
  21. 21. Social and economic effects Long term, Basin scale  small economic effect Short term, local scale  small communities with high reliance on irrigation will be most at riskEffects of drought atLake Alexandrina,Milang, South AustraliaPhoto: Jim DonaldsonYarrawonga Weir andLake MulwalaPhoto: Michael Bell
  22. 22. How much moreenvironmental water is needed? Basin wide Additional 2,800 GL/y (long-term average) however since 2009 890 GL therefore recovered by 2019 < 1,900 GL to be recovered
  23. 23. Indicative rebalancing 2,700 GL/y Interceptions 33% 8,100 GL/y Diversions consumptive Additionalenvironmental water 16,800 GL/y Environment 67% environment 5,100 GL/y Flow to the sea North — 25%, 75% South — 44%, 56%
  24. 24. Implementation Major rural reform — will take time The Basin Plan as part of a plan for the Basin Will need a ‘whole of government’ response to minimise impacts on local communities States and community will be vital part of the implementation through developing and implementing regional Kulcurna area on the Chowilla floodplain before water resource plans environmental watering, 2010 Photo: Corey Brown Need less focus on the SDLs and more focus on how the extra water is used
  25. 25. Strategies for adjustment Irrigators • Commonwealth Current Basin Plan buybacks ($3.1 billion) Interceptions Interceptions • Modernisation program ($5.9 billion) 42% Consumptiveconsumptive Diversions Diversions Environment Environment 58% Environment Communities/environment businesses • Lost water = $ lost to towns/regions Flow to the sea • Debt levels high Flow to the sea due to drought • Mitigating impacts — government assistance?
  26. 26. Opportunities Time extension to 2019 provides opportunity In 2012 the Basin Plan will recommend ‘indicative SDLs’ for each catchment and the Basin This is within a ‘constrained’ system Opportunities to address some of these constraints (with potential changes to SDLs) Opportunity to Kulcurna area on the Chowilla floodplain after progress towards more environmental watering, 2010 Photo Corey Brown contemporary river management
  27. 27. ConstraintsOperational constraints change river operating rules (currently focused on consumptive water delivery) optimise storage managementPolicy constraints modify storage carryover rules water sharing plans — alter to better protect environmental water during droughts remove state-based policies that impact of environmental outcomesPhysical constraints remove/modify infrastructure that impede high flows purchase easements to allow high flows to be delivered adopt engineering works and other innovative solutions
  28. 28. An adaptive plan • More buybacks Final SDL • Address some constraints Consumptive water • • More modelling & science Environmental works Indicative SDL Gap 890 GL/y 850 GL/y recovered recovered Environmental water2004 2009 2012 2015 2019National Water Basin Plan Basin Plan Basin PlanInitiative commenced adopted ‘pause point’ fully enforced SDLs need to be met
  29. 29. Summary Development and implementation of the Basin Plan — major rural reform Significant reductions in current diversion limits required Commonwealth investment ($9 billion) should ‘purchase’ all the water required But still need a whole-of-government response Azure kingfisher. Photo: David Kleinert to minimise impacts on some local communities Many opportunities to progress towards more contemporary river management by addressing many of the current constraints This is a ‘journey’ we have just begun