Salinity in Australia

Salinity is one of the most serious land degradation problems facing Australia today. There are three forms of salinity that are of concern in Australia, Dryland salinity, Irrigation (wetland) salinity and increasing salinity in Australia’s waterways.

Dryland salinity normally occurs when deep rooted (normally native) vegetation is removed and replaced by shallower rooted crops and pasture. There is a lower evapotranspiration rate in these communities than the deeper-rooted communities and this allows the water to move more freely through the soil mobilising the stored salts and raising the groundwater closer to the soil surface. This then results in saline seepage (Young, 2000). The deposited salts can also then find their way into waterways and have an affect on water salinity also. Dryland Salinity is a large problem in South West Western Australia and the lower reaches of the Murray-Darling River system. In 1998-2000 approximately 5,706,000 ha in Australia had a high risk of developing a dryland salinity problem (See Figure One) and there was 2.5-3 million ha already affected, this was estimated to expand to 17,000,000 ha by 2050 (State of the Environment, 2001).

 

Figure One (not included here)- Areas at high risk of Dryland salinity by 2050 due to high water tables (State of the Environment, 2001)

It was concluded by the State of the Environment Report (2001) that Australia has a continuing and increasing dryland salinity problem because of the scale of land use changes needed, the lag time between implementation and resulting environmental change, and the lack of viable options for farmers to implement recommended land use change.

Irrigation salinity is a build up of salts at or near the surface of the soil in irrigated areas. The build up is caused by over applying irrigation water in areas without adequate drainage at the base of their soil profile. As the water table is mobilised and begins to rise it mobilises the soluble salts, the plants roots become water logged and as the water is deposited on the surface it evaporates leaving its salt content behind. This problem can combine with saltwater intrusion when the salty water drains into freshwater streams.

This problem occurs in many parts of the world but is a greater issue in Australia as the soils naturally have a higher salt content (Aplin, 2002). This form of salinity is less widespread than dryland salinity as the total area of land affected by dryland salinity is double that of irrigation salinity (Young, 2000).

Irrigation salinity can be used as an example of how a lack of knowledge and an over response to a problem in lieu of the knowledge can have severe consequences for the environment. In this case the over reaction to the perceived lack of water has led to over irrigation and then the salinity problem. It also illustrates a short-term response to land management and economic issues that should not have occurred (Aplin, 2002).

Saltwater intrusion is a form of water salinity, it occurs along the coast where seawater replaces over exploited groundwater in aquifer systems. The increasing salinity of Australia’s waterways is one of the most significant threats to aquatic health and irrigation (State of the Environment, 2001). There are large areas of South West Western Australia and the lower reaches of the Murray-Darling river system where in-stream salinity is an issue (see figure two). Dryland salinity increases the salt content of groundwater and surface water (Charman and Murphy, 2000). Nationwide about 80 important wetlands are affected by salinity, and this is predicted to rise (State of the Environment, 2001).

Figure Two (not included here)- Catchments where in-stream Salinity is currently an issue (State of the environment, 2001)

The major cause of land and water salinisation in Australia is dryland salinity, and the area of land affected is predicted to triple in size over the next fifty years. Secondary salinisation can be caused by over-irrigation; however, its effects are often localised and can be more easily managed (State of the Environment, 2001).

Salinity is complicated issue in Australia. It is a classic example of the differences between natural boundaries and political boundaries. Water is a State resource in Australia according to the constitution (Aplin et al., 2000) so over the years each state has evolved its own approach to water management. An example of this is the Murray-Darling basin, the Murray-Darling basin covers 1/7th of Australia’s landmass and crosses four states and the Australian Capital Territory (Queensland, New South Wales, Victoria and South Australia) (Harding, 1998). The problem has occurred as the upstream states develop policies and strategies that directly affect downstream users without consultation. As a result the downstream states (chiefly South Australia) often have to engage in some very hard bargaining to get the other states to adopt reforms that will improve the water quality and flow (Harding, 1998). The only way that this could be avoided was to create a management body (The Murray-Darling Basin Commission) that followed the natural boundaries rather than the political ones, although this still hasn’t resolved or prevented interstate conflicts as shown by the St George Offstream Storage basin proposed by Queensland (Harding, 1998).

Salinity is a nation wide problem in Australia, although it is restricted to different regions in the country rather than spread across the whole country evenly. Some regions of Australia, most notably the Western regions of the Murray-Darling river system and South West Western Australia have naturally high salinity levels and human disturbance is therefore more likely to result in a salinity problem (State of the Environment, 2001).

Another aspect of salinity that makes it a problem is the fact that it persists in the landscape. If all harmful practices were to stop overnight salinity problems would still worsen for years. This is without considering the fact that there are technical and political reasons stopping the problem from coming under control (Walker, 1994). It can take from 10-100 years for irrigation salinity to completely bring salt to the surface of the land as the nature of the landscape, groundwater depth, catchment clearing rates and amount of rainfall and irrigation all have an affect. Even when changes to land use are made however it will take decades or centuries to reverse the rise in groundwater levels (State of the Environment, 2001). Depending on climatic patterns it could take between 60 and 2700 years to re-establish hydrological equilibrium (Young, 2000).

Salinity is such a huge problem in Australia that there is no single solution that could possible solve the problem quickly, easily and effectively. For the purpose of this paper the environmental problem that decision-making is attempting to solve will be Dryland salinity as this is the most damaging salinity problem in Australia and it has flow on affects to other salinity problems.

There are many different ways in which people and groups feel dryland salinity should be managed. The broadest divide in these approaches is control the rising groundwater or prevent the rise. Technical methods of control include pumping the groundwater into evaporative pans on the surface where the water evaporates leaving a salt crust on the surface, Groundwater drainage is where drains are placed below the surface leading saline water into waterways rather than contaminating soil. Accession of groundwater could also be minimised by improving irrigation methods, surface drainage and land use and crop management. More ‘natural’ methods of control are ‘retiring’ land (withdrawing it permanently from production allow the natural vegetation to re-establish). Land retirement is unpopular politically and therefore normally occurs unplanned and often not in appropriate locations. A more popular ‘natural’ solution is to maintain the natural vegetation (Walker, 1994). Initially the expectation was that technical (often engineering) solutions would solve the problem, but it has now become clear by the scale of the issue that engineering could never be the only solution (The State of the Environment, 2001).

There are many different organizations that are trying to manage the dryland salinity problem in Australia at different scales and with differing levels of success. There are four main scales at which decisions are made about salinity, these are National (Australia wide), State (a single state), Regional (a region or catchment affected by salinity, this can cross political boundaries) and Local (small almost site specific).

On an Australian wide level there have been many different programs related to dryland salinity. The National Dryland Salinity Program was in effect from between 1993 and 2003. This was an ‘expert’ driven program as it aimed to bring together hydrologists, soil scientists, agronomists, economists, social scientists and policy advisers and had over 50 interrelated research projects. The National Dryland Salinity Program ran over two five-year phases (NDSP, 2003). This program was an attempt to generate a strategic approach to managing dryland salinity problems. In the year 2000 the federal government announced a broad ranging initiative to tackle dryland salinity in key catchments and regions across Australia. It intends to build on work established by other bodies. It states the need for Australian’s to work together in partnership across public and private sectors and a range of activities and policies would be needed (State of the Environment, 2001).

As the States in Australia have the main responsibility for environmental and natural resource issues there are also strategies for dealing with salinity in place at a state level. The New South Wales Salinity Strategy is an integrated land management approach that manages native vegetation, water and soils together. The strategy uses eight key tools to harness different but complimentary skills of the stakeholders involved in the issue of salinity management in New South Wales (NSW Department of Land and Water Conservation, 2000). All other states in Australia also have salinity strategies or equivalent policies.

The two best regional examples of Dryland salinity management can be found in the Wheat belt of South West Western Australia and the Murray Darling Basin. The Wheat belt is an example of a region that is contained in a political boundary and the Murray Darling Basin is an example of a region that crosses political boundaries.

In the South West Western Australia salinity (and how it was caused) was identified as a problem as early as the 1920’s but there was no response to the concerns till later in the century. This region exists within the boundaries of one state and this means that it can be managed by a single state based salinity management policy. This makes management of this significant salinity affected region less complex then regions that overlap political boundaries.

The Murray-Darling basin is a region that crosses many political boundaries and this makes management far more complicated. It is a classic case of inconsistencies between natural and political boundaries (Harding, 1998). It was because of all the political boundaries the region crossed that the Murray-Darling Basin Commission was formed in 1988. The brief the Murray-Darling Basin Commission has covers the most comprehensive set of environmental management goals agreed upon by the states (Aplin et al., 1999). Due to the threatening results of Murray Darling basin-wide salinity audit a basin-wide Salinity Management Strategy was released in September 2000. This strategy was developed by the ministerial council of the six governments involved (Queensland, New South Wales, The Australian Capital Territory, Victoria, South Australia and The Commonwealth Government) and will put in place a comprehensive set of control measures throughout the catchments of the whole basin. The strategy has four aims, to protect water quality equally for all water users, to control salt loads with a cap on the end of valley loads for all catchments, to control land degradation and preserve biodiversity and to identify and allocate responsibility for implementing, managing and monitoring the operations. The strategy sees the principle actions it needs to take as putting a cap on the amount of salt flowing from the tributaries in the main channel, providing a system of credits and debits to enforce this cap, creating an investment bank for revegetation, land use changes and other resource investments, creating additional salt interception works to ‘buy time’, increase research and development on new land uses and land use practices that utilise more drainage water yet maintain clean runoff and implementing greater adoption of best practice in irrigation, cropping and grazing practices (State of the Environment, 2001). Problems with this regional method is that it has a cumbersome decision making process and there are limitations on the powers of the commission as they need political will to be made to work (Walker, 1994).

Finally there are also more local attempts to control salinity. This is because prevention of soil salinisation must be on a catchment basis using a number of approaches integrated to local circumstances (Charman and Murphy, 2000). Local groups are particularly active in North-Central Victoria. Most local groups will be part of a regional network however so experience and knowledge can be shared but local mutual interest bases can be retained. Another advantage is the local approach concentrates the problem down into manageable sites (Aplin, 2002).

Salinity is also a difficult environmental problem as there are no proponents or opponents to the issue. This isn’t a straight environmental issue with one group calling for the end of an environmentally damaging industry, and another group promoting commercialisation as an opposition. This issue is concerned with differences of opinion with regards to the technicalities of managing the salt problem.

All of these factors combined have led to an incredibly complicated decision making process with regards to salinity in Australia. The scale of the salinity issue in Australia and the number of different decision-making bodies with regards to salinity complicates matters greatly.

The decisions that have been made about salinity in Australia vary according to the scale of the decision-making bodies influence. At a national scale most of the decision-making has a strategic focus aimed at providing guidance for decision makers at a smaller scale. At this scale much of the process is expert driven and focused on increasing knowledge, for example the National Dryland Salinity Program. The reason for this would also be related to the fact that the States have the legislative power in regards to the environment, not the federal government.

Decisions made at a state level are more related to slowing the increase in salinity down and tools to achieve this. These strategies are more inclusive than the expert driven national ones and less focused on awareness building and more on guidance. The New South Wales Salinity Strategy needs the government to work with community to set salinity targets the community is prepared to live with. There will be economic incentives for managing land for environmental outcomes and smarter regulation also (this regulation change is something that cannot occur at a national level).

Decision making at regional levels depends on the political boundaries crossed by the region. The Murray Darling Basin needed a specific body set up to oversee the region due to the number of political boundaries that it crossed. This enables there to be consistency across the whole catchment with regards to the decisions made. The drawback to this is that the performance of the Murray Darling Basin Commission in an emergency is likely to be inadequate due to it slow decision-making process and the limitations to its powers placed on it by the states. An intergovernmental organization like this however does enable the governments to see things in the same way and this does go some way to making up for its shortcomings if it can achieve some form of political consensus (Walker, 1994). The West Australian Wheat Belt is a region that does not cross any political boundaries however so therefore it can be governed at a state level and relates to the decision making process at this level greater than it does to a regional area that crosses political boundaries.

Local salinity programs are normally conducted according to a framework developed at a higher scale so much of the decision making process has already been made already at higher levels. Local salinity programs are focused on minimising the effects of salinity.

The various governmental bodies are the main influence on the decision making process. This is because salinity affects everybody in the region to a certain degree not just the property owners. Salinity has social and economic effects that concern governments along with the effect that salinity can have on water quality. Because the various governments have been so involved with salinity recently there has been less of a need for Non-Government Organisations to get involved, this is the same for community groups and industry. None of these groups are as involved in the decision making process as they are for other environmental problems because they don’t need to convince the government that it needs to get involved, this could be due to the fact that community concern of the problem didn’t develop until the 1970’s (Conacher and Conacher, 2000) and governments had been aware of salinity as a problem since earlier in the century. The decision makers consult community groups in the process regardless of this factor though.

One of the biggest stakeholder disagreements is areas of the issue that decisions need to be made about that are considered to be political ‘no go’ zones. A key example of this is land retirement this is a euphemism for temporary (but possibly or even probably permanent) removal of areas of land from productivity to allow native vegetation to return. This is a highly unpopular issue with farmers and landowners who see it as an attack on their livelihood despite the fact the many responsible commentators feel it is essential. Farmers feel they will not be adequately compensated for their land if there is compulsory retirement and are therefore highly opposed to the issue. Farmers are a highly powerful political lobby group and their opposition to this idea has led to political discussion about land retirement becoming taboo subject and therefore no decisions (either for or against) land retirement can be reached, this can only worsen the problem (Walker, 1994).

Essentially decision making about the issue of salinity has been hampered by the very complexity of the issue. The huge scale of the problem has also caused difficulty as this has resulted in many different bodies being established to deal with what is often the same issue in different (or possibly even overlapping) regions of Australia. To improve decision making relating to salinity there needs to be a coordinated approach at least on a catchment/regional basis and if possible coordinated from a national level. Political boundaries need to have less power than natural ones also to entail effective management. To do this bodies such as the Murray-Darling Basin Commission need to have more power to make decisions. There should also be greater involvement of the people affected by salinity in the decision making process so that they are more willing to adopt the measures decided upon.

References

Aplin, G., (2002), Australians and Their Environment: an introduction to environmental studies, 2nd edition, Oxford University Press, Melbourne

Aplin, G., Beggs, P., Brierley, G., Cleugh, H., Curson, P., Mitchell, P., Pitman, A. & Rich, D., (1999), Global Environmental Crises: an Australian perspective, 2nd Edition, Oxford University Press, Melbourne

Australian State of the Environment Committee, (2001), Australia State of the Environment 2001, Independent Report to the Commonwealth Minister for the Environment and Heritage, CSIRO Publishing on behalf of the Department of the Environment and Heritage, Canberra

Charman, P. & Murphy, B. (eds), (2000), Soils: their properties and management, Oxford University Press, Melbourne

Conacher, A. & Conacher, J. (2000), Environmental Planning and Management in Australia, Oxford University Press, Melbourne

Department of Land and Water Conservation NSW, (2000) Taking on the Challenge: the NSW salinity strategy, NSW Department of Land and Water Conservation, Sydney

Department of Land and Water Australia, (2004), Breaking Ground: key findings and research outcomes from 10 years of Australia’s national dryland salinity program- an overview, Land and Water Australia, Canberra

Harding, R. (ed), (1998), Environmental Decision Making: the roles of scientists, engineers and the public, The Federation Press, Sydney

Walker, K. (1994), The Political Economy of Environmental Policy: an Australian introduction, UNSW Press, Sydney

Young, A. (2000), Environmental Change in Australia Since 1788, 2nd Edition, Oxford University Press, Melbourne