At first glance the proposed desalination plant in Wonthaggi looks a winner. After all, the technology works and the long Victorian drought is now generally understood to be permanent. But there are two major problems with desalination. First of all it provides a solution to the water crisis as if it were disconnected from climate change. Second, it reassures Melbourne households, business and government agencies that their outdated infrastructure and wasteful practises are OK - it is the silver bullet we’ve all been waiting for!

Global warming is lowering rainfall across the state and the warmer it gets the more droughts and occasional floods there will be. Water, or lack of it, and global warming are inextricably linked. Yet desalination is a silo attempt to tackle the water crisis and by so doing the Victorian State Government is only exacerbating the problem.

Desalination is a highly energy intensive process. The proposed plant at Wonthaggi is expected to add 2 per cent to Victoria’s greenhouse gas emissions every year. And yet the amount of water processed will only produce the equivalent of that required to power two of the regions four coal-fired power stations.

As more usable water is generated by desalination more greenhouse gases are generated which warm the climate which in turn produces lower rainfall and a greater need for desalination. It is a vicious cycle that is ultimately unsustainable. Desalination will guarantee water, but at what cost? Like Saudi Arabia, in time we could have all the water we need for spa baths and other water guzzling appliances but be surrounded by desert.

This reality is that Melbourne is served by much bigger dams than other cities in Australia and the rest of the world. Water shortages have arisen because demand has now outstripped supply. The Wonthaggi desalination plant will add to supply and divert effort and investment in less costly and more environmentally benign alternatives. What the state government’s desalination decision means is that it is not prepared to tell Melbournians they actually don’t need any more water.

It might be raining less, but even so, much more rain falls on the average size urban property than the average water consumption of the family that resides there.

But it gets worse because not only do we fail to capture much of the water that falls, but a large percentage of what we collect in our near-empty dams is subsequently lost via a leaking and inefficient reticulation system.

However the real crime is how we use what is left. Two thirds of the world’s population uses less than 50 litres of water per day. The average Australian family despite living on the driest continent on earth uses 1,100 litres a day, 80 per cent of which is used to flush toilets, do the laundry and water the garden. Restrictions in Melbourne are stopping garden watering on all but two days a week but there is no obligation to be more efficient elsewhere.

People in the country rightly see city folk as wasteful and not made to appreciate the value of water. While most of rural Victoria is on stage 4 restrictions or higher and has been for some time, Melburnians are offered a project worth $3.1 billion to guarantee their profligate use.

Make no mistake this is a political fix that is as visionary as blind man being led by a cat masquerading as a guide-dog. At a forum in Wonthaggi organised earlier this month, many of the 400 who attended have been roused from their slumber by the “not in my backyard” syndrome. However they now realise that desalination is not a solution for anyone’s backyard.

At the forum Tony Cutcliffe summed up desalination best as “something you do when you run out of time, money and ideas to do anything else”. We obviously haven’t run out of money but it could be so much better spent, whether on rebates for rainwater tanks, fixing the many leaks in the reticulation system or providing incentives for business to improve their water and energy efficiency.

Where there’s a will, there is a way, but because this project has been deemed of “state significance” by the Victorian Government, any obligation to go through an independent public process has been swept away. And contrary to the process with the Gunns’ pulp mill, the Wonthaggi desalination plant is unlikely to be captured by the Federal environment laws which still lack the greenhouse trigger that was promised by the Howard Government back when those laws were passed.

That’s not to say the environment won’t be damaged; it will. The fact that a four-meter diameter pipe will suck up five truck loads of marine organisms a day suggests the sea bed will soon be become an underwater desert. Brine will cause further trouble, as will a big industrial plant set down in idyllic farmland tucked behind the dunes of a pristine beach.

So it’s back to the public of Victoria and in particular Melburnians, who this plant is to serve. They need to understand the issue and determine for themselves whether we really need a business as usual, engineering approach to our water consumption that will take vast resources away from more sustainable and cheaper alternatives.

They should also think about the urgency of climate change and see the link between water shortages and global warming. We have a choice and desalination should be the last resort.

Lyn Allison is a senator for Victoria and leader of the Australian Democrats.