Quantifying environmental water needs – eWater Ecological Tools

1. Quantifying environmental water needs – eWater Ecological Tools eWater Road Show 21 Feb – Part 5 of 5 Dr Nick Marsh eWater

2. Using eWater tools to approach the problem • Identifying the problem – who are the stakeholders and how will they be affected? • Concept • Quantifying the environmental benefit of a given watering scenario • Eco Modeller • Determining how much additional water may be required • Eflow Predictor

3. Wivenhoe Dam

4. Wivenhoe Dam – after heavy rain Jan 2011

5. Eco Modeller: Blackfish in the South Esk River

6. River Blackfish habitat requirements • Magnitude: How much water do they need? • Duration: how long do they need it for? • Timing: When do they need it? • Frequency: How long between successful events? • Rate of Change: do rapid rates of flow change influence success?

7. Blackfish in Esk River

8. Example 2: Consider River Red Gum vegetation communities in Barmah forest

10. River Red Gum habitat availabilityEco Modeller results • Two modelled scenarios (110 years 1896-2006) • Predevelopment = all consumptive use turned off for entire period • Current = all current consumptive use turned on for entire period • Score = Mean annual habitat score (% of ideal) 45 % to 50% decrease in the mean annual habitat score from predevelopment to current scenario

11. Volume of augmented flow Commence to fill trigger ML/d days

12. Consider adding more water –eFlow Predictor • Create some new flow scenarios by increasing the flow at specific parts of the hydrograph to mimic the natural frequency of these small events

13. What impact do these flow changes have on River Red Gum? 4.4% flow increase 2.6% flow increase 1.0% flow increase

14. Hattah Lakes RAMSAR wetland ~ 20 lakes Part of 48,000ha Hattah-Kulkyne National Park Credit to Stuart Little (MDBA) and Bernard McCarthy (MDFRC)

15. Murray Icon site assets Birds Colonial nesting waterbirds - includes ibis, egrets herons and spoonbills Waterfowl and grebes - includes the flood dependent species such as grey teal, pinkeared duck, freckled duck, Australasian shoveler, great-crested grebe, hoary-headed grebe • Fish • Golden perch • Silver perch • Macquarie perch • Australian smelt • Bony herring • Carp gudgeons • Southern pygmy perch, Hardyheads • Galaxias rostratus • Freshwater catfish • Australian smelt • Bony herring • Flathead gudgeons • Murray Cod • Trout cod • River blackfish • Two-spined blackfish • Crimson-spotted rainbow fish • Carp gudgeons • Vegetation • River red gum forest • River red gum woodland • Black box woodland • Lignum shrubland • Rats Tail Couch grassland/ • Edge • Cumbungi (Typha) rushlands • Phragmitesaustralisrushlands • Spiny mudgrass (Moira grass) grasslands • Giant rush rushlands

16. 3 times as many high stress years Average habitat halved or worse Hardly any recruitment opportunities Good years halved or worse

17. Good years = > 75th percentile of natural Fish Birds Floodplain veg Wetland veg

18. Ecological tools to help water management • Concept • Gaining consensus in system understanding and problem definition • eFlow Predictor • Predicting the how much environmental water is required • Eco Modeller • Defining ecological water requirements and quantifying the impact of alternative flow regimes

19. www.ewater.com.au • www.toolkit.net.au