State of the Environment

2006

Indicator: IW-46 Implementation of COAG principles

Data

An independent assessment in 2001 stated that progress in allocating water for the environment in an adaptive management framework is less than satisfactory in a number of jurisdictions. Most jurisdictions have not been able to provide evidence of ecological outcomes of delivering water for the environment for a number of reasons, including:

Source: Jones, G Whittington, J McKay, J Arthington, A Lawrence, I Cartwright, S and Cullen, P 2001, Independent assessment of jurisdictional reports on the environmental achievements of the COAG Water Reforms, Cooperative Research Centre for Freshwater Ecology, Canberra, viewed 16 Nov 2005, http://freshwater.canberra.edu.au.

No jurisdiction has provided environmental water allocations for all of its river systems. While most jurisdictions have made some progress (NSW, VIC, WA, QLD, ACT, SA), considerably more needs to be done; for example, in the unregulated systems of NSW, more than half the rivers of QLD, the River Murray in all States, significant parts of VIC and SA, and all of TAS and NT.

Source: Jones, G Whittington, J McKay, J Arthington, A Lawrence, I Cartwright, S and Cullen, P 2001, Independent assessment of jurisdictional reports on the environmental achievements of the COAG Water Reforms, Cooperative Research Centre for Freshwater Ecology, Canberra, viewed 16 Nov 2005, http://freshwater.canberra.edu.au.

Murray Darling Basin Case Studies

The average annual runoff within the Murray-Darling Basin has been estimated to be 24 300 GL/yr. Under Reference conditions (the 1993/94 Cap), some of this water (12 000 GL) was used for irrigation, while the remainder was either used by the riverine environment en route (7400 GL, through evaporation, seepage, filling of wetlands etc), or flowed out to sea (4900 GL). The estimated proportions for each of the other flow scenarios are presented in the table below.

Proportion of annual runoff within the Murray-Darling Basin being used for irrigation, by the environment and flowing out to sea (assuming no change in total runoff)
Scenario Irrigation Riverine environment Flowing out to sea
Natural 0 GL (0%) 12 000 GL (49%) 12 300 GL (51%)
Reference (1993/94 Cap) 12 000 GL (49%) 7 400 GL (30%) 4 900 GL (20%)
350 GL/yr 11 650 GL (48%) 7 580 GL (31%) 5 070 GL (21%)
750 GL/yr 11 250 GL (46%) 7 660 GL (32%) 5 390 GL (22%)
1500 GL/yr 10 500 GL (43%) 7 800 GL (32%) 6 000 GL (25%)

Source: Scientific Reference Panel for the Murray-Darling Basin Commission 2003, Ecological assessment of environmental flow reference points for the River Murray System: Interim Report, Cooperative Research Centre for Freshwater Ecology, viewed 14 Dec 2005, http://thelivingmurray.mdbc.gov.au/reports.

In November 2003 the Ministerial Council decided to recover 500 gigalitres of water per year over the next five years, as a first step towards restoring the health of the River Murray system. The First Step decision marked the beginning of the Ministerial Council's collective actions to return the River Murray to the status of a healthy working river.

The First Step decision focuses on achieving environmental benefits at six significant ecological assets:

In 2003, COAG announced that, upon signing an intergovernmental agreement, $500 million would be made available to address water over-allocation in the Murray-Darling Basin to minimise adverse social and economic impacts.

Indicative annual investment targets for the MDB under the Intergovernmental Agreement
  2004-05 2005-06 2006-07 2007-08 2008-09 Total
Indicative Investment Target $64m $112m $112m $112m $100m $500m
Commonwealth (40%) $25m $45m $45m $45m $40m $200m
Victoria (23%) $14m $26m $26m $26m $23m $115m
New South Wales (23%) $14m $26m $26m $26m $23m $115m
South Australia (13%) $8m $12m $15m $15m $15m $65m
Australian Capital Territory (1%) $0.7m $1.1m $1.1m $1.1m $1m $5m

Source: Murray-Darling Basin Ministerial Council 2004, Living Murray Business Plan, Murray-Darling Basin Commission, Canberra, viewed 16 Nov 2005, http://thelivingmurray.mdbc.gov.au/reports.

Indicative water recovery targets for the MDB within each jurisdiction under the Intergovernmental Agreement
  New South Wales Victoria South Australia Australian Capital Territory Commonwealth Government
Indicative Volumetric Target 249 GL 214 GL 35 GL 2 GL -

Source: Murray-Darling Basin Ministerial Council 2004, Living Murray Business Plan, Murray-Darling Basin Commission, Canberra, viewed 16 Nov 2005, http://thelivingmurray.mdbc.gov.au/reports.

Summary of state diversions (GL) from River Murray (NSW, Vic, SA) and Darling River (NSW), 1982-83 to 2003-04

Summary of state diversions (GL) from River Murray (NSW, Vic, SA) and Darling River (NSW), 1982-83 to 2003-04

Source: Murray-Darling Basin Commission Annual Report 2003-2004, http://www.mdbc.gov.au/publications/annual%20reports/AR_2003-04/index.html

Water trade in the Murray Darling Basin

Large volumes of water were traded temporarily across the River Murray system in 2003-04 - more than 20 GL traded into South Australia before the end of summer. Trade for the remainder of the season saw water being sold back upstream (mostly to New South Wales), so that by the end of the year the net trade into South Australia was about 6 GL.

Large volumes were permanently and temporarily traded out of the Goulburn Valley resulting in about 60 GL of water being available.

About 50 GL were available from the Murrumbidgee Valley during 2003-04. About 24 GL were transferred to the River Murray via the Snowy Mountains Scheme and a similar volume was delivered past Balranald to supplement low levels in Lake Victoria.

By the end of July 2003, South Australia had experienced the longest period on record of regulated flows. The pattern of flow to South Australia during 2003-04 contributed to water quality problems in the lower reaches of the River Murray.

River flows in the Murray Darling Basin

The dry conditions experienced in 2002-03 limited opportunities for improving environmental flow conditions in the River Murray system, including limited watering of the Barmah-Millewa Forest. The extended drought caused continued stress to River red gum communities downstream of Barmah-Millewa.

The Darling River flow upstream of Menindee Lakes was extremely low from October 2001 until January 2004. The salinity of water in Lake Wetherell rose by December 2003 to about 8000 EC in the deeper parts. An environmental release of water from Lake Wetherell was made in January 2004 to reinstate flow in the lower reaches. High alert levels of blue-green algae were recorded in the lower Darling River during the low flow period prior to the releases from Menindee Lakes in January 2004.

Algal alerts occurred across most of the river system occasionally reaching high levels. Hume Reservoir experienced persistent algae alerts. Algal levels in South Australia were consistently low except for some medium and high alert readings in the lower lakes and Coorong.

Salinity in the Murray Darling Basin

Salinity levels in the River Murray were generally very low for much of the year. The transfer of high-quality water from Hume Reservoir, coupled with low inflows and drainage returns due to the extremely dry conditions, resulted in some of the lowest salinity and turbidity readings observed. The river salinity at Morgan averaged 360 EC in February 2003, which is about 260 EC below the 20 year average of 620 EC. Salinity levels in parts of the lower lakes, however, were high early in the season (4000 to 5000 EC) and fell to about 1000 EC in October 2003. Salinity levels steadily increased over the remainder of the season to about 2000 EC, with some higher readings caused by intrusions of seawater.

An unprecedented salt slug entered the Murray from the Darling River early in 2004. The peak salinity of more than 4000 EC from the Darling was reduced to about 1300 EC through mixing with fresh Murray water below Wentworth Weir.

Murray Mouth

In September and October 2003 approximately 280 GL of water was released from Lake Alexandrina to the sea (compared to median flows to the sea of 11 400 GL per annum under natural conditions). This was the first release since December 2001 but was insufficient to scour any significant volumes of sand from inside the Mouth. Without sand pumping, it is most likely that the Mouth would have closed.

Source: Murray-Darling Basin Commission 2004, Murray-Darling Basin Commission Annual Report 2003-2004, Murray-Darling Basin Commission, Canberra, viewed 16 Nov 2005, http://www.mdbc.gov.au/about/annual_reportage.

2002-03 Audit of the Cap

An independent audit of the cap was conducted in October 2003 and February 2004. Key conclusions were:

Examples of River Murray environmental flow management actions
Environmental Flow action Successful implementation? Scientifically demonstrated improvement in river health?
In-channel variation of flow Applied on the upper and lower river system Demonstrated ecological benefit on the Mitta Mitta River.
Wetland watering through delivering allocations, and enhancing natural floods Applied on private and public wetlands. Environmental allocations achieved. Demonstrated ecological benefit on private wetlands within the MIL area, the Barmah-Millewa Forest, Moira Lake, Werai Forest, Wanganella Swamp, and Victorian Murray wetlands.
Restoration of wetland hydrological regime using local structural and operational manipulation Applied on Moira Lake and SA Riverland wetlands Demonstrated short-term ecological benefits; overall long-term improvements in ecological health not yet evaluated.
Flows to disperse blue-green algae Applied on lower Murray and Darling Rivers Some limited evidence of ecological benefit.
Weir pool drawdown Applied from time to time for maintenance at several weirs, and annually for environmental reasons on Stevens Weir; some resistance to experimental environmental drawdown elsewhere Salinity impacts within tolerable range at Mildura for short drawdown. Salinity impacts may be significant if river flows are low or if drawdown is for an extended period. Ecological benefits not yet demonstrated at Mildura Weir or at Stevens Weir
Weir pool surcharging associated with flood enhancement Applied on the lower River Murray (Lock 5) Demonstrated ecological benefit
Sediment flushing flows Applied at the Murray Mouth Applied flow insufficient capacity, so sediment flushing not yet demonstrated
Mimic shape of natural hydrographs Applied on the lower Darling River Not monitored.
Temporarily open weir gates to allow fish passage Applied at Torrumbarry Weir and Stevens Weir Open passage demonstrated; overall significance to fish movement not measured

Source: Gippel, J 2003, Review of achievements and outcomes of environmental flow initiatives undertaken on the extended River Murray System to August 2002, Murray Darling Basin Commission, Canberra, viewed 16 Nov 2005, http://thelivingmurray.mdbc.gov.au/reports.

What the data mean

Progress on allocating water for the environment under the CoAG initiative has been slow.

Data Limitations

Quantitative data on implementation of aspects of the initiative are limited.

Issues for which this is an indicator and why

Inland Waters - Human response - policy and management - Environmental flows allocation and management 

Implementation and continued observance of the COAG water reforms is a requirement for States and Territories to receive their full share of the payments under the National Competition Policy. Monitoring of their implementation should provide critical indicators of the seriousness and effectiveness of environmental flows allocation and management.

Other indicators for this issue:

Inland Waters - Catchment scale influences - Hydrological condition - Ecological aspects of river flow regimes 

The COAG principles include provisions for allocating water for the environment. Implementation of the COAG water reforms should enhance the ecological aspects of river flows. Monitoring of their implementation should provide critical indicators of the effectiveness of environmental flows allocation and management, and should ultimately result in improved hydrological and ecological condition of river systems.

Other indicators for this issue:

Inland Waters - Human response - policy and management - Management of surface and groundwaters 

The sustainable yield of a groundwater or surface water system refers to the volume and/or rate of water that can be extracted from that system while maintaining an acceptable level of aquatic ecosystem health. The sustainable yield can indicate environmental stress on an aquatic ecosystem if water extraction is greater than the sustainable yield. Sustainable yield can also be used to help identify aquatic systems where water use can be increased in a sustainable manner.

Other indicators for this issue:

Biodiversity - Pressures on biodiversity - Changed hydrology 

The COAG framework includes provisions for allocating water for the environment, which should have a positively effect on some pressures on biodiversity over the long term. Monitoring of their implementation should provide critical indicators of the effectiveness of environmental flows allocation and management, and should ultimately result in improved hydrological and ecological condition of river systems.

Other indicators for this issue:

Further Information

National Competition Council

COAG

MDBC

Key

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