Environment Institute Seminar Series 7 Justin Brookes


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Associate Professor Justin Brookes illustrates the challenges facing water resources in South Australia.

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Environment Institute Seminar Series 7 Justin Brookes

  1. 1. Environment Institute Science Seminar Series 2009 Adapting to a drier Australia: The challenges facing water resources Presented by: Assoc. Prof. Justin Brookes
  2. 2. Acknowledgements Kane Aldridge Dan Rogers George Ganf David Paton
  3. 3. Overview <ul><li>The importance of lakes and rivers </li></ul><ul><li>Running down of the lower River Murray </li></ul><ul><li>Dealing with a crisis </li></ul><ul><li>Investing wisely for the long-term </li></ul>
  4. 4. The value is greater than the exploitable resource <ul><li>Conduit for transport of plant growth enhancer to farm </li></ul>Pulp stored on stump RIVER FOREST
  5. 5. LAKES – The canaries in the landscape <ul><li>Sensitive indicators of catchment modification and climatic conditions </li></ul><ul><li>Integrate across landscape, hydrology and climate </li></ul>
  6. 6. What are our lakes/rivers and wetlands telling us <ul><li>Coorong </li></ul><ul><li>Lower lakes </li></ul><ul><li>Main River Channel </li></ul><ul><li>Chowilla </li></ul>
  7. 8. The realities of the current situation
  8. 9. <ul><li>Irrigation agriculture </li></ul><ul><li>Tourism and fisheries </li></ul><ul><li>Ramsar-listed wetland </li></ul><ul><li>Living Murray Icon site </li></ul><ul><li>Spiritual home of the Ngarrindjeri </li></ul>The Coorong, Lower Lakes and Murray Mouth
  9. 10. A region at a cross-road… <ul><li>Reduced Murray inflows </li></ul><ul><li>Drying of the Lower Lakes </li></ul><ul><li>Decline in water birds and estuarine fish </li></ul><ul><li>Siltation of the Murray Mouth </li></ul><ul><li>Hypersalinisation of the Coorong </li></ul>5,000 – 15,000 1990’s 5,000 – 19,000 2000’s 23,000 – 36,000 1980’s 250,000 1960’s # small waders Years D. Paton, U. Adelaide Red-capped plover
  10. 12. Invertebrate Distributions MM NL SL
  11. 13. Southern most end
  12. 14. Links to food: Black Swan
  13. 15. Salinity tolerance
  14. 16. Salinity responses
  15. 17. CLLAMM ecology Salinity NORTH LAGOON 0 30 60 90 120 150 180 Scenario 1: ‘Do Nothing’ Scenario 2: Minimum Flow Scenario 3: Low Flow Scenario 4: Medium Flood Scenario 5: Large Flood SOUTH LAGOON 0 30 60 90 120 150 180 Scenario 1: ‘Do Nothing’ 1 Scenario 2: Minimum Flow Scenario 3: Low Flow Scenario 4: Medium Flood Scenario 5: Large Flood
  16. 18. Pumping options
  17. 19. The state of the Lower lakes <ul><li>Limited water </li></ul><ul><li>Receding shoreline </li></ul><ul><li>Acid sulfate soils </li></ul><ul><li>Salinity incursions </li></ul><ul><li>Invasive species </li></ul><ul><ul><li>( Ficopotamus ) </li></ul></ul><ul><li>Loss of habitat </li></ul>
  18. 20. Lower Lakes
  19. 22. Ficopotamus
  20. 23. Acid sulfate soils
  21. 24. Tookayerta Creek Finniss River Currency Creek Point Sturt Pen 6 – Goolwa Channel Project Photo - March 2008 (minus 0.43 m AHD) (A) $11.5 m, 6 wks Laffin Point (F) $3.3 m, 8 wks (F) $2.14 m, 8 wks (C) $13 m, 12 wks (D) $15.5 m, 20 wks (G) $45m, 32 wks (E) $100m, 50 wks Stony Point Clayton Mud Islands Mundoo Is Hindmarsh Is Dunn Lagoon Goat Is Goose Is Rat Is
  22. 25. Pomanda Island Weir Plus 0.1 m AHD
  23. 26. Lake Albert Strategy <ul><li>Acid mitigation </li></ul><ul><li>Keep it wet </li></ul><ul><li>400-900 ML/day </li></ul>Lake Albert Keep it wet 400-900 ML per day Photos: Paul Harvey
  24. 27. A future scenario CLLAMM ecology
  25. 28. 700km Bloom from Albury to Swan Hill Main River Channel
  26. 29. Swan Reach <ul><li>No significant nutrient input for 500km, 6 months </li></ul><ul><li>260km upstream from Mouth, </li></ul><ul><li>-1m AHD </li></ul><ul><li>Major observations </li></ul><ul><ul><li>Macrophyte stands establishing as water draws down and clears </li></ul></ul><ul><ul><li>Phytoplankton productivity low </li></ul></ul><ul><ul><li>Absence of large zooplankton </li></ul></ul><ul><ul><ul><li>Dominance by small rotifers </li></ul></ul></ul><ul><ul><li>Compromised food web </li></ul></ul><ul><ul><ul><li>Fish underweight, terrestrial subsidies </li></ul></ul></ul>Brachionus
  27. 30. Propping up ecosystems Chowilla Horseshoe pre- and post-watering. CHOWILLA FLOODPLAIN
  28. 31. Environmental watering <ul><li>If we water wetlands without connectivity then we have local benefit only </li></ul><ul><li>No new carbon to system </li></ul><ul><li>N,P to fuel river productivity </li></ul>
  29. 34. Regulator
  30. 35. Chowilla 5,655 ha inundated 6000 ML/day 10,000 ML/day +regulator mn Simulate 60,000 ML/day 9559 ha
  31. 36. The cost of mismanagement and drought <ul><li>Wellington weir $160 million </li></ul><ul><li>Clayton weir $26 million </li></ul><ul><li>Pump water to Lake Albert $14million+ </li></ul><ul><li>Pump out Coorong $15 million </li></ul><ul><li>Dredging Murray Mouth $32million+ </li></ul><ul><li>Remedial reveg $10 million </li></ul><ul><li>Chowilla regulator $30 million </li></ul><ul><li>Pipes to Narrung, Milang $120 million </li></ul><ul><li>Desalination Plant $1.4billion+ </li></ul><ul><li>(Annual operating cost $108million) </li></ul>
  32. 37. <ul><li>Engineering works should be viewed as interim measures for conservation not as permanent solutions to replace flow </li></ul>
  33. 38. Setting a flow target and sustainable diversion limits <ul><li>Baseline flow set by downstream target 1850GL entitlement + 500 GL </li></ul><ul><li>maintain Coorong once salt pumped out </li></ul><ul><li>floods overlying this </li></ul><ul><li>Upstream impacts </li></ul><ul><li>Lakes maintained above 0.5m </li></ul><ul><li>Mixed river for cyanobacterial control </li></ul><ul><li>Connectivity main channel and wetlands </li></ul><ul><li>Chowilla flooded using regulator 1 year in 3 </li></ul>
  34. 39. An unrealistic ask? <ul><li>2350 GL baseline against 14000 GL historical </li></ul><ul><li>85% of SA water need </li></ul><ul><li>(212GL potable) </li></ul><ul><li>7% of national GDP from SA </li></ul>Historical Cotton 7% water – 0.1% GDP Rice 6% water – 0.02% GDP
  35. 40. Lakes as canaries in the landscapes <ul><li>The Canary in the coalmine </li></ul><ul><ul><li>A Short but meaningful life </li></ul></ul><ul><li>Are we racking up an environmental debt that we can never repay? </li></ul><ul><li>Act to build sustainable environmental and irrigation systems </li></ul><ul><ul><li>Facilitate a transition to a drier state </li></ul></ul><ul><ul><li>Prepare to make tough choices </li></ul></ul><ul><li>Spending on weirs and pumping to patch a broken system is short-term </li></ul><ul><li>Address the environmental water problem while it is “still affordable” </li></ul><ul><ul><li>Supporting any engineering solutions must be a commitment to return freshwater flow in the medium term </li></ul></ul>
  36. 41. Environment Institute Science Seminar Series 2009 Shifting species distributions under climate change Presented by: Professor Miguel Araújo Director, BIOCHANGE Lab National Museum of Natural Sciences, Madrid, Spain