ewater tools for managing Environmental Water Nick Marsh Yorb Pty Ltd 30 May 2012

Transcription

1 ewater tools for managing Environmental Water Nick Marsh Yorb Pty Ltd 30 May 2012

2 To save one of these: Flooded Barmah forest (CSIRO) It cost one or more of these: Water allocation and planning methods need to be: Rapid Robust Repeatable Defensible Expandable Tandou Cotton under irrigation Farmline website

3 Environmental Water Planning How do you define water requirements for assets? What is the science underpinning water requirements? What are the ecological consequences of different watering scenarios? How much water is required for an asset? How much water is required for a collection of assets? What is the watering priority? What do I do in a dry year?

4 Example: River Red Gum vegetation communities in Barmah forest

5 River Red Gum Woodland water requirements Mature trees: Duration: 1 to 5 months is good, longer than 2 years is bad Timing: Anytime is good, but in the second half of the year is best. Time between floods: Preferred return interval is less than 5 years Recruitment: Duration: as per adults Timing: similar to adults, but best success for Sept, Oct, Nov Floods Time Between Floods: no preference as the seed bank is long lived

6 River Red Gum habitat availability Eco Modeller results Two modelled scenarios (110 years ) 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) Asset Predevelopment Current River Red Gum Forest Adult 27% 14% River Red Gum Forest Recruitment 47% 23% River Red Gum Woodland Adult 11% 6% River Red Gum Woodland Recruitment 39% 19% 45 % to 50% decrease in the mean annual habitat score from predevelopment to current scenario

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

8 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 Option 18,300ML/d 60 days return to pre-development frequency 4.4% 18,300ML/d 30 days return to pre-development frequency 2.6% 18,300ML/d 30 days max 1 in every 2 years 1.0% Additional Water Cost (% of current)

9 What impact do these flow changes have on River Red Gum? Increase in mean annual habitat score RRGF Adult RRGF Recruitment RRGW Adult RRGW Recruitment 4.4% flow increase 2.6% flow increase 1.0% flow increase 60 days nat freq 30 days nat freq 30 days max 1 in 2 years freq Scenarios

10 Shared resource for the industry Ecological research, modelling groups, Govt. science groups, Consultants, Project reviewers 1) Process models (e.g. hydrological) 2) Measured or synthetic data build models select models e.g. Generic Species model Aggregated results and links to scenarios

11 Generic Species Model

12 Habitat modelling Habitat Reproduction / survival Predator Immigration Emigration Predation Population

13 Hattah Lakes RAMSAR wetland ~ 20 lakes Part of 48,000ha Hattah- Kulkyne National Park Credit to Stuart Little (MDBA)

14 Murray Icon site assets Fish Vegetation 1. Golden perch, 2. Silver perch 3. Macquarie perch 4. Australian smelt, 5. Bony herring, 6. Carp gudgeons, 7. Southern pygmy perch, Hardyheads, 8. Galaxias rostratus 9. Freshwater catfish 10.Australian smelt, 11.Bony herring, 12.Flathead gudgeons 13.Murray Cod, Floodplain 1. River red gum forest 2. River red gum woodland 3. Black box woodland 4. Lignum shrubland 5. Rats Tail Couch grassland/ Wetland 1. Cumbungi (Typha) rushlands 2. Phragmites australis rushlands 3. Spiny mudgrass (Moira grass) grasslands 4. Giant rush rushlands Birds 1. Colonial nesting waterbirds - includes ibis, egrets herons and spoonbills, 2. Waterfowl and grebes - includes the flood dependent species such as grey teal, pinkeared duck, freckled duck, Australasian shoveler, great-crested grebe, hoary-headed grebe 14.Trout cod, 15.River blackfish, 16.Two-spined blackfish. 17.Crimson-spotted rainbow fish, 18.Carp gudgeons. 6 Fish 3 Birds 8 Flood plain Vegetation 12 Wetland Vegetation

15 Differential impact of current water regime 90% 80% Decrease in mean annual habitat score Fish Birds Floodplain veg Wetland veg 70% 60% 50% 40% 30% 20% 10% 0%

16 Increase in stress years 350% 300% Increase in poor years Fish Birds Floodplain veg Wetland veg 250% 200% 150% 100% 50% 0%

17 Decrease in recruitment years 120% 100% Decrease in good years Fish Birds Floodplain veg Wetland veg 80% 60% 40% 20% 0% 20%

18 Longest time between recruitment events 1400% 1200% Increase in longest time between good years Fish Birds Floodplain veg Wetland veg 1000% 800% 600% 400% 200% 0%

19 LYNC: Lowbidgee, Yanga, Nimmie- Ciara Location specific Eco Modeller application

20 Why have a DSS to plan watering? Two temporal problems: 1) Long term (planning) - Compare flow regime A with flow regime B. 2)Short term (operational) - Given the last 10 years of drought, and a small amount of supplementary water this year how should we use it? Two ways to answer these temporal problems 1)Spatially - report risks to the 60 reporting locations. 2)By species report risks to species

21 10 Key Species Fish 1. Common Carp 2. Murray Cod 3. Un-Specked Hardyhead Frog 1. Southern bell frog Birds 1. Colonial nesting waterbirds (ibis, egrets, herons,cormorants) Vegetation 1. River red gum forest 2. River red gum woodland 3. Black box woodland 4. Lignum shrubland 5. Tall Spike Rush

22 LYNC: Lowbidgee, Yanga, Nimmie-Ciara

23 Ecological research, modelling groups, Govt. science groups, Consultants, Project reviewers 1) Process models (e.g. hydrological) 2) Measured or synthetic data 1) Review watering priorities 2) Review water availability

24 Environmental Water requirements are all about: Magnitude Duration Timing Frequency Rate of Change (Pattern) Photo : Hattah Lakes : DEWHA

25 eflow studies identify important flow components Duration Frequency Magnitude Timing

26 Different approaches to defining water needs Four different Flow Rules 1. Baseflow 2. Highflow 3. Pattern 4. Translucency Photo courtesy of TRaCK

27 Baseflow Rule: minimum flow requirement What time of year is important? Add up short floods to a minimum percentage of time or days duration What is the minimum duration to consider? Flow threshold? natural drought?

28 Flood / Fresh Rule: high flow event Continuous flood, add up short floods or specify a number of floods If multiple small spells, is there a minimum duration? If multiple spells should there be a gap between them? Are there maximum rates of rise and fall restrictions? Days Rate (ML/D) Percentage daily percentage change

29 Flow pattern rule: Specific hydrograph shape Specify the shape of the flow pattern

30 Translucency: allow flow to pass through a dam Define the end of the event either by Volume of dropping below a threshold Look to some upstream node as the basis for the translucency

31 Augmentation strategy for each flow rule Use the natural flow to trigger and event start. If you are in an event, then extend it (piggy backing) Force a release of water to make sure the rule is met at some interval Natural Natural frequency Extend Force /1/1903 0:00 6/1/1903 0:00 7/1/1903 0:00 8/1/1903 0:00 9/1/1903 0:00 10/1/1903 0:00 11/1/1903 0:00 12/1/1903 0:00

32 Conditional Rules: wet years vs dry years Same forest, different year, different water needs Photos courtesy of the Living Murray Program (Koondrook-Perricoota)

33 Multiyear variability in demand: Condition For crop water demand, based on water availability we will either put in a crop or not. We are not interested in a partially successful crop. For the environment we have to consider: Triage when there is no water around but things are nearly dead what are our priority assets Maintenance for average water years we want to keep adults healthy Recruitment in wet years like 2010 we want to create flood events so that everything can reproduce. We need a system whereby we can predefine each of these conditions and allow the environmental demand module to select which flow rule should apply.

34 Flow rule collections allows variable rule selection Consider these rules all the time Only consider one of these rules each time step

35 Eco Modeller Designed for assessing alternative water use / delivery scenarios eflow Predictor For determining how much environmental water is required

36 Freeware - utility models for specialists 10,000 users in over 120 countries

37 Tools to support environmental water planning and management 1. Eco Modeller Predict the habitat consequences of alternative watering strategies Eco Modeller DSS example - Lowbidgee, Yanga, Nimmie- Ciara (LYNC) Location based implementation of Eco Modeller for the lower Murrumbidgee 2. eflow Predictor How much water is required to meet environmental requirements 3. River Analysis Package For analysing and manipulating flow data 4. Water Quality Analyser Store, Analyse, Report water quality data 5. Concept Dynamic conceptual models for system understanding and problem definition

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