Report 8

Management of Salinity

Key findings

Dryland salinity is a significant cost to agriculture and infrastructure, and a major risk to water resources and biodiversity

  • It is estimated that between 1 and 2 million hectares (up to 10% of total land) in the agricultural regions of the South West are salt affected. DPIRD calculates that the opportunity cost of lost agricultural production as a result of dryland salinity since 2009‑10 is $519 million per annum. Without some level of intervention, dryland salinity will continue to be a significant cost and major risk to the State. The extent of salinity affected land in the South West is expected to more than double over the next 50 to 100 years to around 5.4 million hectares. Of this, 4.5 million hectares is agricultural land.
  • Salinity also has a significant impact on water resources, biodiversity and infrastructure. DWER estimates that almost every stream and river in the South West is affected to some extent by salinity. In 2010, the then Department of Environment and Conservation estimated that 850 endemic flora and fauna species were at threat of extinction as a result of dryland salinity. Cost and impacts on infrastructure assets such as roads, railways and buildings are not accurately known, but local governments estimate salinity can halve the life of roads.

The scale and cost of intervention could be very large, and government needs to decide what is feasible and economically viable

  • For large scale improvements, DPIRD estimates that over 80% of the Wheatbelt would need to be replanted with deep rooted trees and shrubs to stabilise and lower water tables. Water tables would take decades to fall and the current extent of broad scale agriculture would no longer be possible.
  • Agencies advise that recovery from dryland salinity is only feasible in discrete catchments and they have focused efforts on individual assets that warrant protection. On a landscape scale, more achievable and feasible management goals are to contain the area impacted or adapt to the saline conditions. Options include revegetation, drainage systems, planting salt tolerant plant species or adopting alternative land uses. The choice for government is to decide how much intervention is feasible and economically sound.

Read more…Dryland salinity is a significant cost and major risk to the State

The State does not have all the information it needs to effectively manage salinity

  • Agencies do not have good information about the current extent, impact and cost of dryland salinity and are therefore not well positioned to manage the risks and provide direction and advice. In large part, this is because since 2008 agencies have reduced monitoring and evaluation, and the Soil and Land Conservation Council, the key independent advisor to Government, has not met since 2003. This impacts on the State’s ability to manage salinity effectively and efficiently, and increases the risk that poor decisions will be made.
  • DPIRD conducts limited monitoring and reporting, and its estimates of the extent of dryland salinity are out of date. The last satellite imagery analysis that mapped salinity was in 2000. At that time, DPIRD calculated that severely salt affected land was increasing by 14,000 hectares per year. The Department does not know if this rate of increase has continued, decreased or accelerated.
  • DPIRD monitors water tables throughout the South West. Because there is a link between water table height and salinity this does provide an indication of areas at risk. DPIRD reported water table data in 2013, however, there are gaps in the data and DPIRD has advised that its monitoring effort has reduced since 2010.
  • Recently, Government has recognised the need to develop a greater understanding of how to manage WA soils and has taken some steps to address this. In December 2017 it announced the formation of a Ministerial Advisory Committee to guide the re‑establishment of the Soil and Land Conservation Council.

Read more…The State does not have all the information it needs to effectively manage salinity

There has been little coordination of efforts between agencies, landholders and stakeholders

  • There is currently little coordinated management across government agencies, landholders and stakeholders. As a result, efforts to manage dryland salinity are unlikely to achieve any landscape wide improvement.
  • The management of dryland salinity lacks strategic direction. Neither the State Salinity Action Plan nor the State Salinity Strategy were completed. Since 2008, both have been dormant and are now outdated. The absence of clearly defined outcomes, and good information on what works, increases the risk that limited funding is not spent efficiently. For example, it is not clear how effective the $560 million investment of state and federal funds between 2003 and 2008 was because agencies have not continued to monitor and evaluate outcomes.
  • Salinity is spread unevenly across the landscape, resulting in varying impacts. Addressing it is a shared responsibility and experience to date indicates that effectiveness relies on coordinated local action. It also relies on all landholders taking appropriate action to protect their land, even those who are not affected and stand to gain relatively little.
  • There are currently no goals and targets for reducing water tables or planting deep-rooted species and decisions to protect land are left to individual landholders. Relying purely on private benefit can result in landholders either acting alone, or not at all.
  • Mechanisms exist to help more collaborative approaches, such as the functions of the Commissioner of Soil and Land Conservation, the Soil and Land Conservation Council, and Land Conservation District Committees. But these are not used, which increases the risk that some landowners will take appropriate actions while others will not. Inaction by a landowner can have a significant impact on their neighbours.
  • DPIRD measures to prevent land degradation are mostly reactive and reliant on applications for drainage or complaints from the public. It is not effectively using its legislative powers to prevent land degradation. With up 2 million hectares affected by salinity, and the problem predicted to get worse, we would expect a more proactive approach to the prevention and mitigation of land degradation.
  • DPIRD advised that since 2008, it had investigated 303 land degradation complaints and only 2 were directly related to dryland salinity. A further 39 complaints were related to unapproved drainage which the Commissioner for Soil and Land Conservation stated may have been about salinity.

Agencies have protected individual assets but overall are not meeting legislated responsibilities

  • Agencies have focused on protecting individual, high value assets in local areas. This has resulted in some success for those assets. However, agencies are not meeting wider legislated responsibilities to prevent and mitigate land degradation, and protect water resources and biodiversity throughout the South West.
  • DPIRD has responsibilities under the Soil and Land Conservation Act 1945 (the Act) to prevent and mitigate land degradation, promote soil conservation and encourage and educate landholders. DPIRD does not own or manage agricultural land apart from a few research stations. It works to ensure a profitable and sustainable agricultural industry by conducting research and providing advice on a range of agricultural issues. It can also investigate complaints about land degradation but does little to directly manage salinity.
  • DBCA and DWER have wide responsibilities to protect the environment and manage water resources. They advised that given the widespread scale of dryland salinity and limited resources they have prioritised which assets they protect. These were originally identified in the Salinity Action Plan. They acknowledge that while they have had success with some of those assets, other water resources have become more saline and native flora and fauna remain at significant risk.
  • In the early 1990s, DBCA started recovery works to protect biodiversity in 6 South West wetland catchments. In 2002, the Government committed to increasing the number of recovery catchments to 25, however this was never done. Work in the recovery catchments has since been reduced based on available resources and changed priorities. DBCA currently provides a direct staff resource and funding to implement recovery actions for 2 wetland catchments; Toolibin Lake and Lake Bryde. They also conduct broader wetland projects and research at other sites that includes monitoring water depth and salinity levels.
  • The Salinity Action Plan identified 5 key water resource catchments in the South West for DWER to manage. These catchments are declared under the Country Areas Water Supply Act 1947. Interventions by DWER in the Kent and Denmark River catchments were successful in reducing salinity levels, especially the Denmark River where the salt levels are now within Australian Drinking Water Guidelines. DWER remains active in the Collie River (Wellington Dam) and Denmark River catchments. For many other rivers in the South West such as the Avon, Blackwood, Warren/Tone, Pallinup, Gairdner and Lort, salinity levels continue to increase.

Read more …There is little coordination of efforts to manage dryland salinity

Page last updated: July 29, 2018

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