Transcript PowerPoint - Water Droplets – Mike Young

Water
Prof. Mike Young
Research Chair, Water Economics and Management
The University of Adelaide
Almond Growers Conference, Barossa Valley,
30th October 2008
Murray River at Wentworth, NSW during 1914 drought
(Photo courtesy of the State Library of South Australia)
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Which future is best?

One that gets the fundamentals right, now?
 A system that can be confidently explained as able to
cope -- whatever future arrives

One that commits all to more decades of reform and
uncertainty?
 Incremental progress
 No guarantee of resolution of current problems
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Future-proofing the Basin
www.myoung.net.au
1. A sustainable sharing system for ground & surface
water
2. Put all states under the same inflow sharing regime
3. 100% carry over of all water
4. Require off-set of all land use change that erodes
entitlement reliability (forests, dams, SIS)
5. An independent authority making allocations to
shareholders
6. If still dry, review system configuration & size from top
to bottom
7. Use the $5 billion on offer to restructure the industry
quickly
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Three Concepts
1. Adverse climate change  long drys  droughts

Each challenge needs a separate strategy
2. Rainfall  Yield

Small reductions in rainfall mean big reductions in supply
3. Accounting

When someone takes more someone or something else or
the environment must get less

Increased efficiency has a big downside

Groundwater – surface connectivity matters
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Long drys
TotalTotal
River
Murray
Inflows(including
(including
Darling
River
MurraySystem
System Inflows
Darling
River)River)
Annual Inflow <= 25 000 GL (GL)
25 000
Modelled Current Conditions - Extended Droughts shown in Red
20 000
WET
DRY
15 000
10 000
5 000
Long-term Median Inflow (9 000 GL/yr)
0
1892
1902
8 yrs
1912
1922
1932
1942
12 yrs
1952
1962
1972
1982
1992
2002
52 yrs
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Total River Murray System Inflows (including Darling River)
with post 1938 sequence imposed from 2002
Re-live from 1938
Annual Inflow <= 25 000 GL (GL)
25 000
20 000
15 000
2014
10 000
5 000
0
1892 1902 1912 1922 1932 1942 1952 1962 1972 1982 1992 2002 2012 2022
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0
2004
300
2004
2001
1998
1995
1992
1989
1986
1983
1980
14% less
2001
1998
1995
1992
1989
1986
400
1983
1980
1977
1974
1971
1968
1965
1962
1959
1956
1500
1977
1974
1971
1968
1965
1962
1959
1956
PERTH
1953
1950
1947
1944
1941
1938
1935
1932
1929
1926
1923
1920
1917
1914
1911
Rainfall (m m )
2000
1953
1950
1947
1944
1941
1938
1935
1932
1929
1926
1923
1920
1917
1914
1911
S tr e a m flo w (G L )
Rainfall and yield
Rainfall for Jarrahdale
20%
less
- 1%
1000
500
0
1000
900
S tre a m in flo w fo r P e rth d a m s (P rio r to S tirlin g D a m )
800
700
600
500
4 8 % le s s
- 3%
66%
le s s
200
100
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With half as much water
Users
Users
Environment
Environment
River Flow
River Flow
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Long drys
TotalTotal
River
Murray
Inflows(including
(including
Darling
River
MurraySystem
System Inflows
Darling
River)River)
Annual Inflow <= 25 000 GL (GL)
25 000
Modelled Current Conditions - Extended Droughts shown in Red
20 000
WET
DRY
15 000
10 000
5 000
Long-term Median Inflow (9 000 GL/yr)
0
1892
1902
8 yrs
1912
1922
1932
1942
12 yrs
1952
1962
1972
1982
1992
2002
52 yrs
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Adverse climate change
In Mediterranean climates, a 20% decline in mean rainfall
results in around a 60% decline in mean storage inflow
Mean supply
10,000
Mean supply
4,000
River & Storage Evap 2,000
River & Storage Evap 2,000
Flow to sea
2,000
Flow to sea
Deliverable water
6,000
2,000
Deliverable water
Environment Use
1,500
Environment Use
0
Consumptive Use
4,500
Consumptive Use
0
0
0
0
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Is this ground or surface water?
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Source: Rick Evans
Accounting for Forestry
Annual Evapotranspiration (mm)
1600
Forest
Mixed veg.
Pasture
unknown
Schrieber (forest)
Schrieber (grass)
1400
1200
Trees
1000
Grass
800
250 mm = 2.5 ML/ha/yr
@ $3000 /ML * 0.80% = $6000/ha
600
400
200
0
0
500
1000
1500
2000
2500
3000
Annual Rainfall (mm)
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The state of the system
Monthly flows past Euston
9,000
8,000
7,000
6,000
5,000
Extensive overbank flow
occurs above this line
4,000
3,000
2,000
1,000
A decade without water over bank
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River Murray Active Storage
Active storage
Average storage
Maximum active storage
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Cumulative System Inflows for selected years
16,000
2006/07
14,000
2007/08
2008/09
Average
Projected
12,000
10,000
8,000
6,000
4,000
2,000
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The next challenges
Solving over-allocation – where is the water?
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Volume of Water in the System
A sharing regime or a cap?
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The next challenges
1. Backing the Murray Darling Basin Authority

Murray Darling Basin Authority and a new Basin Plan
2. Developing a Basin Plan that has climate and accounting
integrity

A robust sharing regime
3. Securing an environmental share in a timely manner

Combine infrastructure and acquisition money ($3.1b is not enough)

Expedite expenditure
4. Reconfiguring the River, its lakes and wetlands
•
What do we give up? How clever can we be?
5. Removing all barriers to trade and rationalising
infrastructure investment
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“We don’t have all the answers –
nobody does – but before we start
laying bricks and mortar, we have got
to get the foundations right, otherwise
the cathedral will tumble with the
smallest of tremors.”
Peter Cullen
Wentworth Group of Concerned Scientists
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Contact:
Prof Mike Young
Water Economics and Management
Email: [email protected]
Phone: +61-8-8303.5279
Mobile: +61-408-488.538
www.myoung.net.au