Engineering our way forward through Australia’s salinity challenge

Abstract

Salinisation of Australia’s landscape has progressed at a rate and extent that significant built and natural assets are at immediate or imminent risk of damage or loss. The dominant national paradigm regarding our response to this challenge can be summarised as: if deforestation caused the problem, then reafforestation (or new farming systems that behave hydrologically like forests) is the solution. This view underpins the majority of R&D and dryland salinity management investment, whether through community-based approaches such as Landcare or through the development and establishment of commercial silvicultural or agricultural alternatives. However, over the recent past a number of analyses have been published that reveal the general inadequacy of revegetation approaches for the protection of assets at risk to salinity, given the limitations of time, scale, economics, water yield tradeoffs and in some cases the hysteretic nature of the phenomenon.

While the revegetation paradigm apparently drives much of the public debate and intent, in practice there are a set of engineering approaches aimed at salinity control that have been developed and adopted, often extensively, that have not featured prominently in the sights of NRM agencies, NGO’s or R&D providers. These approaches include surface water control, deep open groundwater drains, groundwater pumping, disposal basins, and regional arterial drainage and flood mitigation structures. It is apparent, at least in Western Australia (where the majority of Australia’s secondary salinity is at present), that stakeholders with assets at immediate risk are electing engineering options to protect those assets. The collective failure of the technical community to direct adequate R&D and commercial investment in this direction has created a vacuum between need, intent and capacity. Expensive earthworks and pumping are going into the Australian landscape with highly uncertain on-site benefits and off-site impacts, largely without the participation of the engineering or scientific professions. Lack of adequate guidelines, design principles, and regional planning will likely lead to uneven performance, elevated risk, unexpected externalities and wasted resources. This paper argues that the technical community has a serious and pressing challenge to bring our minds to bear on the development and extension of proper engineering solutions to Australia’s salinity problem. The commercial potential involved in some of these solutions is explored.

Keywords:

• Salinity
• Australia
• engineering

Additional information

Notes on contributors

Thomas Hatton

Dr Tom Hatton is a Senior Principal Research Scientist with CSIRO. His research focuses on issues of land management from the perspective of providing water to people and the environment. Dr Hatton’s research has ranged across bushfire science, mining reclamation, ecohydrology, environmental water allocation, and salinity. Dr Hatton obtained his Ph.D. from Utah State University shortly before immigrating to Australia in 1986. Following a post-doctoral position in mathematics with the University of New South Wales, he joined what is now the CSIRO Division of Land and Water in 1988. He served on the Board of the CRC for Catchment Hydrology 1998-1999. He is Officer-in-Charge of the CSIRO Land and Water Floreat (Western Australia) Laboratories and serves on the Operations Committee of the National Dryland Salinity Program. Dr Hatton has made significant advances in the measurement and modelling of transpiration, catchment hydrological modelling, the understanding of ecosystem dependence on groundwater, and the management and future of our salinising landscapes. He serves on the Editorial Review Boards of Tree Physiology and Land Use and Water Resources Research. In 1999, he received the Inaugural W.E. Wood Award for scientific excellence in the field of salinity research. In that same year, his scientific contributions were recognised with the Utah State University Alumni Professional Achievement Award.

Postal Address: CSIRO Land and Water, Private Bag No 5, Wembley 6913, WA

E-mail: [email protected]