Transcript Setting the Murray-Darling Basin Scene

Setting the Murray-Darling Basin
Scene
R. Quentin Grafton
([email protected])
1
A Hundred Year Policy Experiment
• Politics is front & centre in water policy and
water reform (change)
• Classic case of trade-offs (upriver versus
downriver; diversions versus environment;
summer flows versus winter/spring flows; instream versus floodplain use;…)
• Parliamentary Inquiry Chaired by Tony
Windsor is latest attempt to “balance” these
conflicts.
2
National Water Initiative
• Para 23
• “...complete the return of all currently
overallocated and overused systems to
environmentally sustainable levels of
extractions”
3
Water Act 2007
• Promote the use and management of the Basin water
resources in a way that optimises economic, social and
environmental outcomes
• to ensure the return to environmentally sustainable levels
of extraction for water resources that are overallocated or
overused; and
(ii) to protect, restore and provide for the ecological
values and ecosystem services of the Murray-Darling
Basin; and
(iii) subject to subparagraphs (i) and (ii) – to maximise the
net economic returns to the Australian community from
the use and management of the Basin water resources
4
Basin Plan and Water Act 2007
Establish SDLs that reflect “an environmentally sustainable
level of take” that will not compromise:
(1) the environmental water requirements of key
environmental assets including water-dependent
ecosystems;
(2) ecosystem services and sites with ecological
significance;
(3) key ecosystem functions;
(4) the productive base;
(5) and key environmental outcomes for the water resource
that, in doing so, the economic, social and environmental
outcomes are optimised and the net economic returns
maximised.
5
Proposed Basin Plan
To meet key environmental outcomes and ecological health
by Basin and catchment
AND
to minimise social and economic impacts on Basin
communities and industries
3,000-7,600 GL
3,000-4,000 GL yet SDLs NOT at lowest cost
6
Public Benefits and Public Costs
• Improvements in environmental outcomes in the Basin
generate national benefits although farmers & Basin
communities likely to receive additional benefits (water
quality, soil productivity, local recreation).
• Will not be achieved by infrastructure subsidies. Public
benefits should be achieved at lowest cost so should buy
water entitlements rather than subsidise infrastructure.
• If “Securing long-term future for irrigation communities” is a
priority then better if allowed flexibility in how money spent
in to achieve communities higher “social” rate of return.
• $5.8 billion for infrastructure ($3.7 billion for state priority) is
not about maximising public benefits but supporting vested
interests (SMDB upstream and broadacre agriculture).
7
Generating Public Benefits
• Effective watering plans that will need both
regional and centralised controls
• Efficiency will likely be improved with
augmented pulse events or timing but “works
and measures” will likely generate only
marginal gains.
8
Regional Impacts of SDLs
• WTM and AusRegion model coupling provides
a solid basis to assess Basin and at a coarse
spatial scale regional impacts.
• WTM provides results comparable to other
models (UQ, CSIRO, the ANU)
9
Politics of Numbers:
Credibility & Who Loses & Who Gains
• Credibility gap: Scenario 2 (p. 33) predicts increase in
Basin employment. Such results need testing to what
happened in the drought.
• How do GVIAP, crop activities, employment numbers
track with worst years (2007-08) of drought?
• Is it possible to link WTM to employment numbers to
indicate transitional job losses by sector?
• Political and community fears are much less about
overall changes in employment but when and where
these employment changes occur.
10
Extensions & Assumptions
• Data matching spatially (SDL region, WTM regions
and AusRegion) and temporally (2000-2001 &
2005-2006) and Baseline (10,500 GL versus
10,940 GL).
• Check the water purchase in some regions
(Goulburn-Broken)
• Incorporate “bridging the gap” in AuRegion likely
to be $3 billion in addition to $3.1 billion in RtB
• Details on SRWUIP and efefct on GVIAP
11