Water Journal : Water Journal November 2014
WATER NOVEMBER 2014 26 Feature Article The ideas concerning climate change were deeply felt by the many attendees at the Busselton Forum, who subsequently began local action groups and lobbying to achieve mitigation and adaptation goals. The Minister for the South West at the time, Julian Grill, was impressed by the depth of scienti c knowledge that was presented by the experts and also grasped that the water sources for Perth and the South West were likely to challenge our creative technical ability and also our political will. He took these views to Cabinet. The need for political support became obvious when the next major water resource was examined for Perth. PERTH'S WATER SUPPLY OPTIONS The history of Perth's water supply has been told in a series of major plans developed over the years. The most dramatic part of this history was the building of the Mundaring Dam and a 900km pipeline that linked Perth to the Gold elds in the east in 1905. This pipeline was a major engineering achievement by CY O'Connor and it remains today linking not just Kalgoorlie, but a large part of the south-west agricultural area. Perth people have grown up on this history and thus have often contemplated the need for big thinking about water. In 1989, in my second time in State Government, we developed for Premier Peter Dowding a Sustainable Development Plan and a Greenhouse Strategy. Both referred to the need for adaptation to reductions in rainfall. The Water Corporation meanwhile was beginning to make plans to expand the water supply more rapidly than expected due to climate change. This led to a series of quick 'low-hanging fruit' options. However, by 2001, when I was again working with the Premier, Dr Geoff Gallop, a major loss of rainfall occurred across the whole year. The Premier established a Water Review Taskforce that identi ed a number of short-term conservation options that were announced immediately, as well as developing a range of long-term options. The major conclusion of the next water supply option was to focus on a large aquifer to the south called the Yarragadee. MINING THE YARRAGADEE The South West Yarragadee is a substantial deep aquifer stretching over 500km in the south-west of WA. It contains over one million gigalitres of water. For comparison, the Gnangara Mound in the Perth region contains around 20,000GL and is a major source of water for Perth, especially during major drought times. The Yarragadee was thus seen as the next major resource for Perth, although it meant piping it up from the south-west. Substantial resources were put into a Sustainability Assessment that enabled not just the detailed hydrology to be determined and the environmental impacts estimated once extraction began, but also the economic and social impacts to be placed on the agenda. The south-west community was very unsure about this proposal. They were already using the resource for Bunbury and Busselton's water supply, but the areas further south from where it would be pumped did not want to lose 'their groundwater' to Perth. A contrary argument was developed by WAWA that the pipes would be able to ow both ways and that in drought times Perth could well be supplying Margaret River. The Expert Panel's report (which I was on) concluded in 2004 that the best option was to go ahead and extract a sustainable level of water from the South West Yarragadee. Other options would not be as cheap, and it was considered manageable to look after the aquifer. The State Government took several months to respond. By the time they got around to making the decision it had been a long, dry summer and a public campaign was able to convince the community that sustainable yields from groundwater may never be achieved again. Rainfall recharge may well continue to reduce. In a highly articulate campaign the South West and the city joined together to demand a better option such as wind-powered desalination that could see us through long-term climate-related reductions in rainfall. A GOVERNMENT DECISION IS MADE With the Yarragadee off the table, there was little option left other than this new technology -- desalination; the technical people in WAWA hurriedly informed us that 'desal' was actually becoming quite cheap due to new membrane technology. A quick decision was made to go with desalination as long as it was wind-powered, due to the sensitivity to climate change issues that had driven so much of the agenda. The response was immediate and positive; the Yarragadee had been saved and an option had been found. The process of planning, procurement and building a desal plant began and the project was completed in late 2006. Today we have not one, but two, desal plants that have been relatively painlessly built and operated and now produce around 50 per cent of Perth's water supply. Unlike the eastern states' desal plants the Perth story of desal has been hugely popular. Water prices have risen, although not by much, and WAWA managed an $800 million pro t in the past year. CONCLUSION The climate is likely to continue to dry out in the south-west corner of Western Australia. Dams and groundwater are going to continue to be stressed if they alone are the water sources. Wind- powered desalination has enabled Perth to adapt to this climate reality. Groundwater recharge of sewage is next. If it stops raining completely the city would still survive. It is a remarkable turnaround from the dire predictions of Tim Flannery. The insights of CSIRO scientists and others who con rmed the likelihood that reduced rainfall was likely to be a permanent reality was the start of this journey. The public in the whole of Perth and the south-west region were highly sensitive to the issue and pushed the politics of resilience planning to the limit by basically saying no to using the Yarragadee aquifer as the major next source. Desalination and recycling of sewage were, therefore, the only real options remaining and the politicians moved quickly to af rm desalination and get it into the water supply system. They have been proved right. As the Paci c Ocean moves into another El Niño drought cycle for the eastern seaboard cities, there will no doubt be a move to use the 'mothballed' desal plants that were built just as it started raining again. Perhaps the far-sighted politicians and their technical advisors who thought it was a good idea to buy them will be nally recognised for their resilience planning, just as they are in Perth. WJ THE AUTHOR Peter Newman (email: p.newman@curtin. edu.au) is Professor of Sustainability, Curtin University Sustainability Policy (CUSP) Institute, Curtin University, Western Australia.
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