It all started with the Commonwealth Water Act 2007, which set up the independent Murray Darling Basin Authority (MDBA) and gave it the job of writing a plan for managing the water resources of the Basin as a whole. The Water Act’s objectives are very clear – it states that the Basin Plan should establish and enforce limits on how much water we can sustainably take out of the rivers of the Murray-Darling (“sustainable diversion limits” or SDLs). The Act says the plan must ‘protect and restore the ecosystems, natural habitats and species’. It also says we need to meet our obligations under international agreements, like the Ramsar Convention on wetlands.
Apart from setting SDLs, the Water Act says the Basin Plan must have two other important parts. The Environmental Watering Plan is the ‘how’ of restoring rivers to health. It sets out environmental objectives for ecosystems as well as targets for measuring progress towards them, and a management framework for environmental watering. The Water Quality and Salinity Management Plan is required to set water quality objectives and targets and to measure and report on how close we are to meeting these.
The Basin Plan has been agreed to by the five basin states – Victoria, NSW, Queensland,South Australia and the ACT – and the Commonwealth Government. All governments are committed to implementing the Basin Plan ‘on time and in full’ but in practice they differ over what that means.
The Plan will return 2,750 billion litres (GL) of the water which is currently being used (mainly for irrigation), to the rivers of the Basin. The volume is broken down into sustainable diversion limits (SDLs) for each of the 23 catchments, and then a component to be shared between catchments to provide water downstream and to keep the Murray mouth open. Keeping the mouth open allows salt to flow out to sea, instead of building up in the river system.
The Commonwealth government has committed to returning an extra 450 GL to rivers by 2024. This water is required by law to be recovered in ways that maintain or improve social and economic outcomes. It may not sound like much water but it would make a big difference to the outcomes of the Plan and for the Coorong it could mean the difference quite literally between life and death.
No. It will make a big difference but it’s not a complete fix. The Wentworth Group of Concerned Scientists has said that it’s impossible to tell from the documentation in the Plan what the outcomes will be.  And there’s years of scientific research that indicates at least 4,000 GL is required to be returned to the Basin’s rivers to have a reasonable degree of certainty that they will be restored to full health.
However if the Plan recovers the full 3,200GL of water and the water is able to get to the parts of the floodplain that need it the most, 17 out of the 18 major ecological objectives of the Plan will be achieved. It’s a huge gain and well worth fighting for.
The MDBA has carried out extensive social and economic research to assess the consequences of returning water to the environment. It has estimated that ‘the level of total production in the Basin (gross regional product) will be reduced by less than 1 per cent and that this is expected to be more than offset by broader economic growth over the transition period to 2019–20’.  That’s not to say that impacts are not being felt in small communities that are heavily dependent on irrigation, and where life is pretty difficult anyway. But overall the benefits of a healthy Basin exceed the costs. 
There are two main ways of recovering water for the environment – buying water entitlements back from irrigators willing to sell, and through upgrading irrigation infrastructure both on and off farm. The Commonwealth Government is investing $13 billion to implement the Plan and is currently investing in irrigation infrastructure at the rate of $2.5 million per day! It’s the biggest investment in the future of irrigated agriculture in Australia’s history.
Examples of the economic benefits of healthy rivers include the $2.1 billion worth of services like water purification and flood mitigation contributed to the nation every year by the Basin’s 16 internationally recognised wetlands (Ramsar sites).  Restoring the Coorong from poor to good condition would be worth $4.3 billion to Australians,  and increasing the frequency of flood plain inundation in the northern basin can increase income for floodplain graziers by over 50 percent.  A healthy basin supports continued profitable agriculture and irrigation as well as improving the condition of birds and trees.
The Basin Plan sets targets for water quality and salinity for all the different catchments, and for salt export through the Murray mouth. But it’s still uncertain how well they will work because their achievement depends on the volume of water recovered for the environment, which is yet to be finalised. There’s no substitute for real water to keep the Murray mouth open and flush salt out to sea. This is really important because the rivers of the Basin supply drinking water to 3.4 million people, including the citizens of Adelaide.
The Murray-Darling Basin is a naturally saline environment, but human activity has increased the amount of salt entering the system to about 2 million tonnes every year. The economic cost of this salt has been estimated at $270 million per year.  If this salt is allowed to accumulate in the river system, it will eventually poison both land and water resources, making them unusable by the environment and for irrigation and drinking water. To export enough salt to stop this from happening, the Murray mouth needs to stay open so that salt can be flushed out to sea. At least 3,200 GL of environmental water is needed to achieve this and keep salinity in the Coorong below critical thresholds . 
No! We know that flows fluctuate widely from year to year, but we also know that there is going to be less water in our rivers in future due to climate change. The Murray-Darling Basin Authority has assumed that this reduction will fall within the historic range of variability so they have not made any allowance for it. This approach is extremely risky, especially in the southern basin (which includes the Victorian section) where rivers are likely to be harder hit. Best practice risk management would adopt a precautionary approach, adapting early rather than delaying until the impacts of climate change become severe.
To date about 1950 GL of environmental water have been recovered. In Victoria the ‘in valley’ targets have been met for each river but there is still a long way to go to recover the downstream component that is required to help keep the Murray mouth open.
Environmental water recovery has been in progress since 2008. In the early years much of the water was acquired through buyback from irrigators who were willing to sell, a method that has been assessed by the Productivity Commission as the most efficient and effective way to recover water for the environment. More recently buyback has fallen out of favour with both governments and communities and water recovery is being progressed through modernisation of irrigation infrastructure to make it more efficient. Water savings can be made both in the channel systems that deliver water to farms and through improving on-farm irrigation equipment and practice. These methods are more expensive, slower and less certain than buyback but more popular so have been prioritised by the Commonwealth and supported by state governments. As a result environmental water recovery has slowed dramatically with only 20 GL added to environmental water holdings in the past 12 months and there are serious concerns that the $13 billion water recovery budget may be inadequate to finish the job..
Not if the upstream states have their way!
At the heart of the Basin Plan is the so-called ‘SDL adjustment mechanism’ which allows the volume of environmental water recovery to be adjusted up (more water for the environment) or down (more water for consumption) within certain limits. This mechanism was included to allow agreement between the states in the making of the Plan.
Victoria and NSW have been putting a lot of effort into designing ‘supply’ measures that are intended to provide equivalent environmental outcomes using less water. These projects include environmental works and measures (channels and regulators) that deliver water to key environmental assets such as individual wetlands. These types of project are absolutely essential in times of drought and water shortage when there is no other way to deliver water, but they are no substitute for real water that supports the full range of ecosystem processes and connects and nourishes the river and its floodplain.
The state governments are also investigating changes to the rules that determine how the rivers are operated.These rules are currently designed to facilitate water delivery for irrigation and it may be possible to make them more environmentally friendly. In addition they are looking at projects that reduce water losses through evaporation and leakage.
On the other side of the ledger the Commonwealth government is in charge of ‘efficiency’ projects that create more water for the environment while maintaining or improving social and economic outcomes. In practice these projects are about improving the efficiency of on-farm irrigation methods so the same value product can be created with less water and the savings returned to the environment. The Commonwealth is hoping to generate the full 450 GL of ‘up water’ through this method but is yet to demonstrate the feasibility of its approach.
A final category of project that can be considered in the SDL adjustment process are ‘constraint management’ projects.These deal with obstacles to or ‘constraints’ on the the delivery of environmental water such as low lying bridges, levee banks and other infrastructure, unintended flooding of private land and unsuitable outlets on dams and weirs. Dealing with these issues can make a huge difference to the effectiveness of environmental water by allowing it to reach the places where it is most needed. Unfortunately these projects lack champions and are unpopular with potentially affected landowners, so are falling to the bottom of the priority order for government action.
The SDL adjustment process was intended to operate in 2016. However given the number and complexity of the projects for consideration the Governments have given themselves an extra year for assessment before making a final decision. The SDL adjustment mechanism will now operate in 2017 with a final figure for the SDLs due by the end of the year. Only then will we know how much water will actually be recovered to implement the Basin Plan.
The outcome for the Basin Plan as a whole is a ‘healthy and working’ Murray-Darling Basin. This includes sufficient and reliable water supplies for communities, productive and resilient water-dependent industries and healthy and resilient ecosystems with rivers and creeks regularly connected to their floodplains and, ultimately, the ocean. The Plan has many more details under these headings but the environmental outcome is defined as ‘the restoration and protection of water-dependent ecosystems and ecosystem functions in the MDB with strengthened resilience to a changing climate (s5.05)
|November 2012||Basin Plan adopted by Water Minister Tony Burke and becomes a legally binding document. Implementation begins including water recovery for the environment by infrastructure upgrades and buyback.|
|2013||Bill to recover extra 450 GL passed by the federal Parliament. MDBA develops constraints management strategy to look at how constraints to the delivery of environmental water can be remedied. Further work on how the Plan will be implemented in the northern Basin started.|
|2014-16||States develop proposals for projects for getting the same or better ecological outcomes using less water/ changing rules/relaxing constraints to deliver more water. Commonwealth develops efficiency projects|
|2015||Water buybacks capped at 1500 GL. Emphasis shifts to infrastructure projects and improving irrigation efficiency, slowing the rate of environmental water recovery|
|Northern Basin review completed, may propose changes to SDLs
SDL adjustment mechanism operates in southern Basin, may change SDLs
2750 GL or equivalent of water recovered for the environment, full implementation of sustainable diversion limits, water resource plans and environmental watering plan by states
|2024||All water recovery and offset projects complete, intended to produce the same or better environmental outcomes than the recovery of 3,200 GL of environmental water|
1. Commonwealth Water Act 2007, s 21
2. Wentworth Group of Concerned Scientists Statement on the 2011 Draft Murray-Darling Basin Plan http://www.wentworthgroup.org/uploads/Wentworth%20Group%20Statement%20on%20the%202011%20Draft%20Murray-Darling%20Basin%20Plan.pdf
3. MDBA (2011) Socio-economic analysis and the draft Basin Plan Part A, p vii
4. MDBA (2011) Plain English Guide to the proposed Basin Plan, p123
6. Morrison M & Hatton MacDonald D. http://www.mdba.gov.au/files/bp-kid/1282-MDBA-NMV-Report-Morrison-and-Hatton-MacDonald-20Sep2010
7. Arche Consulting. Socioeconomics of floodplain agriculture in the Murray-Darling Basin, A scoping report prepared for the Australian Floodplain Association. August 2010.
9. MDBA (2012) Hydrologic modelling to inform the proposed Basin Plan
10. MDBA (2012) Murray-Darling Basin Plan, Chapter 8
11. CSIRO (2008) Water availability in the Murray-Darling Basin. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project
12. MDBA (2012) Sustainable Rivers Audit
13. MDBA (2010) Guide to the Proposed Basin Plan Vol 2
14. MDBA (2012) Hydrologic modelling to inform the proposed Basin Plan
15. CSIRO (2011) Science review of the proposed Basin Plan
16. VAGO (2010) Sustainable management of Victoria’s groundwater resources http://www.audit.vic.gov.au/reports_and_publications/reports_by_year/2010-11/20100510_groundwater.aspx
17. Wentworth Group of Concerned Scientists (2012) Analysis of groundwater in the 2011 Draft Murray-Darling Basin Plan http://www.wentworthgroup.org/uploads/Wentworth%20Group%20analysis%20of%20groundwater%20in%20the%202011%20draft%20Basin%20Plan.pdf
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