Australia State of the Environment Report 2001 (Theme Report)
Prepared by: Jonas Ball, Sinclair Knight Merz Pty Limited, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06750 7
Water quality and sources of pollution (continued)
Salinity of surface waters (continued)
Since Australia: State of the Environment 1996 (SoE Advisory Council 1996) most states affected by salinity have released salinity management plans or strategies with associated funding. The Commonwealth Government has also released a National Action Plan for Salinity and Water Quality worth $700 million over 7 years provided that the states match the funding dollar for dollar. There is some debate whether $1.4 billion is sufficient to manage salinity as other stakeholder organisations have estimated the cost of repairing land and water degradation at $60 billion (NFF & ACF 2000).
A detailed discussion of salinity management strategies is contained in Land Theme Report. The main features of state and national salinity management strategies are summarised in Table 17. As the national and most state salinity management strategies were only released or revised in 2000, it is too early to assess their success or progress.
Before salinity management strategies were developed, state government responses to salinity were at a local or regional scale. In Victoria and South Australia, regional plans to address dryland salinity (and irrigation-induced salinity where appropriate) in the Murray-Darling Basin are being implemented. Measures contained in these plans include catchment and riparian revegetation, changes in agricultural water use and improved groundwater management. In New South Wales, the focus has been on irrigation-induced salinity with plans developed for the Murray, Lower Murray Darling, Murrumbidgee, Lachlan, Central West and North West regions. Up until the release of the New South Wales salinity strategy in 2000, dryland salinity was only addressed on a local catchment scale. In Queensland, salinity is an emerging issue and until the release of their strategy, most efforts have been concentrated on identifying areas affected by dryland salinity.
|State/ region||Year released||Name and details of plan||Major features|
|National||2000||National Action Plan for Salinity and Water Quality(http://www.affa.gov.au/docs/nrm/actionplan/index.html )||Set environmental targets and standards
Integrate catchment and regional management plans
Build community and landowner capacity
Improve the governance framework
Develop a public communication program
|Western Australia||1998||Salinity Action Plan
|Increasing water use by introducing deep-rooted perennial species
Increasing water use by annual crops and pastures
Collecting, re-using and/or disposing of surface water
Draining, pumping and disposing of groundwater
Improving protection and management of remnant native vegetation
|Victoria||2000||Salinity Management Framework
(with catchment salinity action plans)
|Partnerships for integrated catchment management
Understanding catchment processes and implementing appropriate management actions for particular landscapes
Building skills and the capacity for change
Efficient water use and regional growth
Salinity management in the Murray-Darling
|New South Wales||2000||Salinity Strategy
|Salinity management targets for end of valley flows
Encouragement of activities that provide a reduction in salinity and other benefits
Preparation of a Salinity Business Development Program Improved regulatory tools
Improved government advice on salinity
Upgrade of data and analytical tools
Increased research into salinity
Consistent planning approaches across the whole of government
|Murray-Darling Basin||2000||Salinity Management Strategy
|Capping salt loads from tributaries
Establishing a system of credits/debits to enforce cap
Creating an investment bank for improvement works
Building salt interception works
Research into better use of resources
Implementing better agricultural practices
Salinisation of the landscape in Western Australia was recognised in the 1920s. It wasn't until the 1980s, after two decades of intensive land clearing, that salinity management strategies began to be formulated. In the 1990s the immense scale of the salinity problems facing Western Australia were recognised and a statewide salinity strategy was developed in 1996 which focuses on increasing plant water use, changes in cropping practices, revegetation and groundwater management.
A salinity and drainage strategy for the Murray-Darling River system was released in 1989 (MDBMC 1989), with the focus on reducing the impact of irrigation-induced salinity. Salt interception schemes constructed as part of the strategy resulted in a net reduction of 61 EC units in the instream salinity of the Murray River at Morgan. Managed releases of water from storages during periods of low flow further reduced salinity at Morgan by another 28 EC units. Land and water or salinity management plans have been prepared for many irrigation areas and there is anecdotal evidence that in some areas groundwater levels have stabilised or are falling (MDBMC 1999). A review of the strategy undertaken in 2000 (MDBMC 2000) has refocused the major efforts on managing dryland salinity. To provide guidance to river and catchment management in the Murray-Darling Basin, salinity targets for end of river flows are being developed for all river systems in the Basin (MDBMC 2000). These are based on salt loads and/or instream salinities. The cap on diversions from the Murray-Darling Basin may also have a beneficial effect on salinity levels in the Basin by reducing saline groundwater inflows due to over-extraction and over-irrigation and providing environmental flows to dilute saline waters.
The Murray-Darling Basin Ministerial Committee's two strategies highlight two different approaches to managing salinity - namely managing the effects of salinity (i.e. instream salinity) and managing the cause of salinity (i.e. land clearing). Instream salinity can be reduced by salt interception schemes (which divert highly saline pulses of water to evaporation or storage basins), improving irrigation practices and improving drainage of highly saline groundwater. Dryland salinity is managed by reducing land clearing, protecting existing vegetation, revegetation of groundwater recharges areas and increasing water use by crops.
Although there have been some initial successes with salt interception schemes and other engineering works, in the long term they will only provide limited and localised relief and do not address the sustainability of land and water management practices. Planting perennial vegetation and the cultivation of crops that reduce the leakage of water to the groundwater will help prevent or reduce the effects of dryland salinity in many areas. As the clearing of perennial woody vegetation is the major cause of dryland salinity (as well as other problems), management responses to reduce clearing and increase vegetation cover are important. These responses are discussed in the Land Theme Report.
The management of salinity in some instances may involve the abandonment of highly salinised land and inland waters in order to focus limited management and financial resources in areas that can be managed or restored in the medium term. Some salinity strategies (e.g. New South Wales) recognise that some land and water resources will remain affected by salinity and therefore incentives to develop new uses of these resources are required. New uses could include salt harvesting, cultivation of salt-tolerant crops and aquaculture of marine species.
- In the last five years most states affected by increasing land and water salinisation have prepared new or revised strategies to manage and reduce the impacts of salinity. A National Action Plan for Salinity and Water Quality has also been prepared by the Commonwealth Government and a framework strategy for the Murray-Darling Basin has been developed. It is too early to judge the success of the strategies.
- Tools and mechanisms for managing land and water salinity include research, catchment revegetation, protection of riparian and remnant vegetation, establishment of salinity targets for individual river systems, engineering works, salt interception schemes, improving groundwater drainage, increasing water use by plants, cultivation of salt-tolerant crops, salinity trading schemes, consultation with stakeholders, and integrated catchment management. Engineering solutions, such as salt interception and drainage schemes, will only provide localised short-term relief and in many cases only transfer the problem to another area. Long-term sustainable measures such as catchment revegetation and improving plant water use to reduce 'leakage' are the key mechanisms to reducing salinity.