Executive summary
Introduction
In August 2001, the Murray-Darling Basin Ministerial Council (MDBMC) launched the Basin Salinity Management Strategy (BSMS).[1] In November 2002, it approved a revised Schedule C to the Murray-Darling Basin Agreement, to implement the BSMS. Schedule C sets out a framework for:
- establishing agreed Baseline Conditions for the rivers and the landscapes;
- adopting end-of-valley instream salinity targets;
- establishing Registers to record salinity impacts, and to allocate salinity credits and debits;
- establishing an annual reporting regime which provides for assessing progress towards the agreed end-of-valley targets;
- undertaking rolling five-year reviews which improve the predictions of the future salinity regimes with and without further intervention;
- promoting joint works and measures to reduce or limit the rate of increase of salinity; and
- providing for monitoring, assessing, auditing and reporting on the matters set out in the Schedule, and on progress in implementing the Strategy.
Schedule C also provides for the appointment of ‘independent auditors for the purpose of carrying out an annual audit’, whose task is to review progress on implementing the BSMS. The three members of the Independent Audit Group for Salinity (IAG-Salinity) were appointed in January 2004.
The Terms of Reference and Schedule C require the IAG-Salinity to:
- audit the annual review reports of each State Contracting Government and the Commission, of the progress each has made during the year in implementing the BSMS;
- audit Registers A and B;
- reach a consensus about the performance of each State Contracting Government and of the Commission in implementing the provisions of this Schedule in the relevant year;
- reach a consensus on whether the Commission has fairly and accurately recorded the salinity impacts of each action entered in Register A or Register B during the relevant year; and
- provide an opinion regarding the balance of credits and debits for each state.
This report presents the consensus view that we have reached in undertaking the audit covering the year 2005–06. The following summarises the most important of our findings. The main text provides context and the findings and recommendations in detail.
Overview of progress
The reports from partner governments and the consultations have emphasised substantial progress in implementing the BSMS in the last year.
- The Australian Government has provided $500 million to the MDBC, enabling it to improve the rate of implementation of the BSMS and other programs. The joint works program has been accelerated and longer term planning strengthened.
- The Australian Government is also continuing its efforts in driving improvements in monitoring and evaluation so that appropriate and consistent data and evaluation methods are available nationally.
- The regional groups have reported impressive achievements in implementation of their investment plans, but substantial effort is required to evaluate the impacts of the activities on the end-of-valley targets.
- During the year, three salt interception schemes, or scheme stages, were declared effective, the most in any 12-month period to date. The total salt credit at Morgan, South Australia, achieved by the BSMS joint salt interception schemes now in operation, under construction or approved for construction stands at 40 EC units, compared with a year 2007 target of 61 EC. With the acceleration in the joint works program now made possible, a total of 70 EC credit is planned to be achieved by 2010.
- In 2005–06, considerable progress has been made to improve the utility of the Salinity Registers. The register system contained a number of difficult issues not foreseen at the inception of the BSMS. Finding solutions has been a challenge, requiring very close cooperation and sustained input by the states and the Commission. A number of entries on the Registers have been reviewed and substantial improvements have been made in the reliability of the Register entries.
- Victoria has further developed its approach to accounting for salt credits and debits by including more information on reliability of estimates, as well as providing an audit trail for each entry.
- South Australia, Victoria and New South Wales are assessing approaches to evaluating the actual impacts resulting from water trade rather than focusing on the amount in the trades.
- Improved understanding of salt mobilisation, particularly during flood recessions, has been accepted as a priority aspect for further study. Improved capacity to deal with floodplain water and salt processes has been identified as an important technical requirement in each of the last three IAG-Salinity reports. This capacity must include interactive processes of surface hydrology and groundwater systems. At least two states indicated that improvements will only be achieved if much improved land and water resource information is available.
- The Australian Capital Territory has made very limited progress in meeting its Schedule C commitments since last year’s audit.
- The catchment reviews/audits of the Border Rivers – Moonie catchments have highlighted the serious risks to stream salinities from broadacre irrigation in the alluvial plains.
- Preliminary results from the Salinity Audit Update in New South Wales were released to catchment management authorities (CMAs) in February 2006. This update took advantage of the advances in scientific understanding of salinity, new data and technology improvements during the period since the first Basin Salinity Audit was completed in 1999. The results confirm that salinity remains a significant natural resource management issue in New South Wales, impacting on infrastructure and the environment as well as agriculture. However, the findings also indicate that trends in salinity are not as high as predicted in 1999, and that many of the catchments are in a state of dynamic equilibrium. In these catchments the extent of salinity is varying in response to wet and dry conditions, but there is no underlying trend.
The following scorecard, Table 1, is a non-rigorous compilation of the IAG-Salinity’s impressions of the achievements in 2005–06 in various aspects of the BSMS. Apart from the Australian Capital Territory, the jurisdictions significantly strengthened their achievements in the areas shown in the 2004–05 version of this table as relatively weak. These were the Programs of Action, Registers A and B, and the rolling reviews.
1 ACT still to provide.
2 Definite improvements in several regions. Government support strengthened.
3 Major improvements in the last 12 months. Completion of some key reviews is required to determine credit/debit status.
4 Major improvements planned by Australian Government and States.
5 Excellent reports and collaborative consultations.
Progress in implementing Schedule C – issues for special mention
Mid-Term Review
Clause 35 of Schedule C provides as follows:
(1) The Commission must, by 31 December 2007 and at intervals of no more than 7 years thereafter, prepare and give to the Ministerial Council and the Community Advisory Committee, a report upon:
(a) the operation of this Schedule; and
(b) its usefulness and effectiveness in implementing aspects of the Strategy.
The review leading to the December 2007 report has become known as the Mid-Term Review. Much has been learnt during this first phase of the BSMS and there is wide agreement that the upcoming Mid-Term Review is a timely requirement. It is a good opportunity to review past progress, assess the present status of salinity in the Basin, set new goals, and undertake the planning of activities through the BSMS’s second stage. In preparing this audit, the IAG-Salinity was very conscious of the need for all those involved in the BSMS to provide the best possible platform of information, progress, and assessment for the Mid-Term Review.
The MDBC in conjunction with the jurisdictions, has undertaken the necessary initial planning and the Mid-Term Review commenced in mid-2006.
Several of the issues that the IAG-Salinity emphasised last year and again this year should be addressed with urgency to provide objective input to the Mid-Term Review. Some of the more important of these are referred to in the discussion below and the recommendations. More detail is given in the main text of this report.
Coordination
Action has commenced in improving the coordination across jurisdictions of activities impacting on implementation of Schedule C. In particular, the actions by the Australian Government and the Commission will increase the rate of implementation. The IAG-Salinity has gained the impression that a key element missing is a targeted communication process with the regions on BSMS aspects.
Basin and end-of-valley salinity targets and Programs of Action
The salinity risk profile at Morgan continues to be above the target of 800 EC 95 per cent of the time and, according to MDBC preliminary calculations, will go much higher than this by 2100 in the absence of further investment beyond the current program.
Progress on model development and use in evaluating and preparing action plans has been more encouraging than was apparent when preparing last year’s IAG-Salinity report. Nevertheless, it appears that the completion of targets and action plans that fully meet BSMS objectives will extend two or three years beyond the date envisaged at the inception of the BSMS.
Discussions about the competing issues of salinity reduction versus water yield reductions related to reforestation emphasised some of the difficulties being faced by regional groups. Consequently this affects catchment management investment decisions and impacts on the various targets. Evaluation of trade-offs and impacts at the local, catchment and basin scales is complex, and responsibilities and processes for stakeholders to address them are not clear.
Consultations this year have reinforced the IAG-Salinity’s impression that the end-of-valley target strategy needs thorough review across all stakeholders in the BSMS. This issue should be addressed more specifically in the Mid-Term Review and might include an assessment of the degree of technical and process support needed across the various stakeholder groups. Key questions that need to be addressed in the Mid-Term Review are given in the recommendations set out below.
The Salinity Registers
Improvements had been made to the condition of the Registers each year from the commencement of the BSMS up to the time of the IAG-Salinity’s 2004–05 report. Nevertheless, the Registers still remained largely in transition, and were far from being usable for the main purposes of the BSMS. In that report, the IAG-Salinity recommended:
That the States take steps to ensure that the calculation of debits is in line with the provisions of the Protocols, seeking to reach the highest attainable standards of rigour, and that the necessary data be shared with the MDBC without undue delay.
With the active involvement and cooperation of all parties, a major effort was made in 2005–06 to address this recommendation.
Victoria and New South Wales were concerned that when the economic impact of salinity credits and debits was recalculated using the revised cost functions, this would reduce the economic benefits that had been recorded as accrued to them from past investment in salt interception schemes. Accordingly, the parties agreed to include in the Registers an adjustment – the ‘Salinity and Drainage Strategy Commitment Adjustment’ – preserving those benefits to the two states.
The states provided the MDBC with the data they had available to enable the most accurate possible calculation of a significant number of entries. This has resulted in a substantial improvement in the Registers, though further work remains to be done.
The IAG-Salinity’s opinion regarding the balance of credits and debits for each state
Schedule C, Clause 16(1), provides as follows:
16. (1) A State Contracting Government must take whatever action may be necessary:
(a) to keep the total of any salinity credits in excess of, or equal to, the total of any salinity debits, attributed to it in Register A; and
(b) to keep the cumulative total of all salinity credits in excess of, or equal to, the cumulative total of all salinity debits, attributed to it in both Register A and Register B.
Register A currently shows New South Wales, Victoria and South Australia to be in net credit, while Register B shows New South Wales to be in net credit, with Victoria and South Australia slightly in debit.
In the IAG-Salinity’s report for 2004–05, a review of the status of the items on the Registers showed that most of the larger entries at that time, especially debit entries, were of low to very low confidence rating. The IAG-Salinity concluded that, neither Register A nor B could be used with confidence to make judgments on whether the Basin or a state is in overall net debit or credit.
In that report, and more fully in the present report, it is shown that Registers A and B cannot be added together to give a distortion-free overall result. Nevertheless, if a state is in net credit in both, then that state will be in true net credit overall.
In 2005–06, most entries that had low confidence ratings were replaced with data of medium or high confidence rating. However, several entries remain of low confidence rating pending the completion of studies such as the Mallee Tri-State Review. Some of these entries are potentially among the highest figures in the Registers in terms of the economic impact of salinity, and the range of uncertainty is higher than what is shown at present as the level of the net credit of each of the states in each of Registers A and B.
Accordingly, the IAG-Salinity cannot at present make confident judgments on whether the states, or the Basin as a whole, are in overall net credit or debit, though there is nothing suggesting that any state is substantially in debit in either Register at the present time. As reviews due in 2007 are completed, the larger entries with a low confidence rating will be replaced with more reliable figures. The Registers are then likely to come much closer to their full utility as indicators of the credit or debit positions of the states, and of the increases in salinity that could be expected in the absence of further action.
The accuracy of the Commission in maintaining the Salinity Registers
In 2005–06, the MDBC continued to use its established systems to ensure secure record keeping and to maintain and improve the Registers, and made several improvements. Aside from the issues raised above, the IAG-Salinity found no inaccuracies in the Commission’s maintenance of the Registers, as provided to the IAG-Salinity for incorporation into this report.
Updating the Commission’s Salinity Register
The audit did not identify any requirement to update individual entries in the Registers incorporated in this report, aside from the matters referred to above and in the main body of this report.
Recommendations
The IAG-Salinity recommends:
1. End-of-valley targets
That the MDBC request the BSMS Implementation Working Group (BSMS IWG) to determine the effect on salinity at Morgan and its implications for achievement of the Basin Salinity Target, if end-of-valley salt loads and concentrations were in line with the adopted end-of-valley targets, and what changes in end-of-valley targets would be required to meet the BSMS objective of contributing a credit of 10 EC towards the Basin Salinity Target through in-valley actions.
That answers to the following questions be sought in the Mid-Term Review:
- has the outcome of the end-of-valley target-setting process provided appropriate targets for the purposes of meeting the Basin Salinity Target?
- how appropriate are the analytical frameworks for evaluating the impacts of in-valley actions on end-of-valley and Basin Salinity Targets?
- What is the future role of the Basin Salinity Target, and is there a case for modification or extension of the present target? (Section 5.3).
2. Pricing as a salinity management incentive
That the MDBC consider the possible salinity and other benefits of adoption of pricing structures for irrigation water incorporating an efficiency incentive, and advise the Ministerial Council accordingly (Section 5.6).
3. Improving the Salinity Registers
That New South Wales, Victoria and South Australia, in cooperation with the MDBC Office, complete the reviews and provide the reports and information necessary to ensure that the few remaining entries of low confidence rating can be replaced with high quality data. In particular, the work still outstanding on the Tri-State Mallee Review, and a small number of other reviews, should be completed as a priority, to provide important information for the Mid-Term Review (Section 4.1).
4. Resources to ensure BSMS progress
That as a contribution to the Mid-Term Review, the jurisdictions, especially New South Wales, identify funding and staffing gaps and deficiencies that will need to be filled to meet adequately the demands of the next phase of the BSMS. Plans and commitments to fill those gaps should also be presented (Section 5.7).
Implementing the recommendations of the IAG-Salinity’s 2002–03 to 2004–05 reports
Recommendations of the 2004–05 report
In 2005–06, the states, the MDBC and the BSMS IWG actively pursued most of the recommendations of the 2004–05 report. In particular, the rate of implementation of the BSMS was largely restored, and very great efforts were made to improve the condition of the Registers, with most of the outstanding difficulties being resolved. Recommendations on which further work will be necessary are as follows.
Water use efficiency
The 2004–05 recommendations on this topic were:
- that the default root zone drainage estimate for use in SIMRAT or other accredited models be more conservative (at least 15 per cent) unless direct measurements of root zone drainage can be provided.
- that existing credits/debits estimated using SIMRAT be reassessed using the more conservative approach.
- that states and the MDBC give serious consideration to the establishment of key sites across the irrigation zones of the Murray-Darling systems at which the landscape/regolith properties determining root zone drainage and hydraulic conductivity of the unsaturated zone be measured.
Two states did not support the first recommendation above. However, the IAG-Salinity considers that, with little direct data so far, the principle of conservatism should apply; that is, in uncertainty, one should use high-range estimates for matters leading to debits, and low-range estimates for credits. The IAG-Salinity thus continues to hold the view that a root zone drainage fraction of 15 per cent or thereabouts is preferable at present. On the third of the above recommendations, Victoria reports an active investigation that should throw light on these questions in some of its irrigation areas. The IAG-Salinity suggests that efforts to measure root zone drainage and related soil properties should be pursued in irrigation areas more widely across the Basin (Section 5.4).
Irrigation impact zoning
In the 2004–05 report, the IAG-Salinity recommended that:
New South Wales should actively consider establishing an irrigation impact zoning policy for the New South Wales Sunraysia, and that Victoria, and in due course New South Wales, consider extending the zoned area upstream, to cover all high risk areas.
In the light of the high rate of new irrigation development proposals in Sunraysia, the IAG-Salinity suggests that these two states should make implementation of these recommendations a priority (Section 5.5).
Salt accessions during flood recessions
In all its reports so far, the IAG-Salinity has recommended:
That research and investigations be undertaken into the mechanisms leading to salt accessions during flood recessions, with a view to identifying works and measures to reduce post-flood salinities and to understanding related causes of floodplain environmental degradation.
As drought conditions continue, salt continues to build up in and upon floodplain sediments. Much of this salt would be available for mobilisation into the River Murray and some of its tributaries during flood recessions. Little is known, however, about the distribution of stored salt or the mechanisms of mobilisation. There is uncertainty, therefore, about the scale or sequence of flooding required to result in the very high salinities that have characterised some flood recessions in the past. Under The Living Murray program, small areas of the floodplain have been watered to determine the effects of this on stands of dying red gum and black box trees. Work has been done at some of these locations to measure the salt mobilisation effects of the waterings. Partly stimulated by these experiences, some of the states are showing an increased interest in investigations to understand and manage floodplain salt accretion and its mobilisation. Advantage should be taken of the Mid-Term Review to plan a program of such investigations.
[1] Murray-Darling Basin Ministerial Council, 2001. Basin Salinity Management Strategy 2001–2015. MDBC, Canberra.