SOUTH AUSTRALIA'S WATER SUPPLY AND POPULATION

South Australia's Water Supply and the Growing Population

South Australia's Water Supply and the Growing Population

Introduction

Over the past forty or so years South Australia has heavily relied on water from the Murray River. Less water will be available from the Murray in the future because of climate change. While desalination of sea water is too expensive for most commercial irrigation purposes, it is a viable alternative for the reticulated water system at present, and over the past several decades its cost has generally declined. It could be powered by sustainable energy such as wind or solar. (Gargett,1996)

Water Supply for South Australias Growing Population

While capturing storm water runoff and recycling waste water are other options for increasing SA's water supply that should be vigorously pursued, you can't capture storm water runoff if it doesn't rain, and if people are reducing their water consumption then the quantity of waste water is also being reduced. It was announced on 2007/09/11 that South Australia is to build a 50GL/year desalination plant. Is this approach the right one? Is one big desalination plant better than several smaller ones spread around the coast? Has sufficient consideration been given to the effect of the brine and process chemicals that will be released back into the sea?

The Water restriction system that is in place in SA is foolish and will fail to achieve its objectives in the longer term. One of the reasons (the proximate cause) we have a water supply problem in 2008 is the drought that has been plaguing the Murray Darling basin for the past six or eight years. We'm sure that many South Australian gardeners might ponder on the other reason (the ultimate cause - bad management), as they strain their backs carrying buckets of water in an effort to stop their gardens dieing.(Owen,2007)

One very valid objection to desalination has been its substantial energy requirement and the fact that our use of fossil fuels is causing climate change. In fact plenty of sustainable energy would be available from the 2000MW of proposed SA wind farms if our federal government would change its policy from supporting fossil fuels to supporting renewable energy and if our state government was to match its fine words with action; there is so much more that could be done. As things stand, most of these wind farms will not be built.( Gargett,1996)

Chemicals used in the water pretreatment and in the reverse osmosis process itself can also be problematic when they are released, with the brine stream, back into the sea. Coaguants like ferric- or aluminium-chloride are used to improve the initial filtration process and both alkaline and acidic solutions can be used in the RO plants to remove silt deposits, biofilms, metal oxides and scales. (However, We believe that reverse-osmosis seawater desalination plants can be operated without such undesirable chemicals, or at least without releasing them into the waste stream.) More can be read on the Clean Ocean Internet site, the full URL for what is probably ...