Australia's rivers are in crisis

When the River Murray runs backwards – as it did recently – and its mouth closes over, as it is threatening to do, it’s a sign that something is gravely wrong.

We don’t just see the problem in closure of the Murray Mouth, but also in declining water quality, the rising levels of salinity, the dying forests and floodplains, the loss of fish, birdlife and other aquatic animals and plants, the silence of the bush. Old Man Murray is telling us something – and it’s high time we started to listen.

The difficulty is that many of the changes that turn a healthy river into a dying river are imperceptible. They take place over such long spans of time that few people notice them, or recall clearly the way things used to be.

Scientific study of Australia’s rivers and estuaries suggests they can absorb a lot of punishment, degrading slowly until quite suddenly, they reach a point of no-return and the system dies or changes completely for the worse. The challenge is how to awake ourselves to it, in time to prevent a collapse.

We have seen it in the Gippsland lakes, where more and more water was extracted for Melbourne, for the LaTrobe valley and for farming. The loss of flushing with fresh water led, imperceptibly, to the collapse of a healthy brackish water system filled with fish and seagrasses.

It became a turbid, nutrient-polluted, saline system dominated by algae. The salt wedge pushing up from the sea against the weakened flow has largely destroyed the natural system. Nutrients from erosion, sewage and from farming, no longer flushed to sea, have nourished the algae.

It is extremely difficult, if not impossible, to reverse such a process. The only real option is to restore some of the Lakes’ natural flow regime, to put back part of the fresh water. And that requires a complicated discussion and decisions about all the other things we use and value the water for – drinking, power, irrigation, manufacturing. It’s a question of values.

As Australians, we love our rivers, our estuaries, lakes and coastlines. None of us wants to lose them or ruin them.

The irony is that’s exactly what we are doing. In some cases we’re simply unaware of the process, because its signs so hard to read until the crisis breaks.

The threat to our landscape is by no means confined to its waterways. Many people who visit the bush say they come back refreshed because of its silence and peacefulness.

There are two kinds of silence however: natural quiet, and the silence of the tomb. If you visit parts of Australia where the bush is still intact, you will find it is far from silent. Birds, insects and small scurrying marsupials make a constant chorus of sound, which can be quite deafening. That is the bush our forebears went into and enjoyed.

The silence of the bush is like an algal bloom in a great river. They are both signs that the complex web of life that used to prevail has broken, and only fragments of it remain. Where once there were hundreds of species, only a few hang on in the simplified ecosystem. The rest are gone, moved away, locally extinct and sometimes, totally extinct.

Of the 30 species of native fish in the Murray-Darling system, 16 are now threatened and one, the trout-cod, is rated as critically endangered. Like the coal-miner’s canary, the fish are telling us the water is no longer healthy enough for them to live in.

We also have a $10 billion irrigation industry that depends on drawing water from the rivers of the Murray-Darling system. In turn it supports Australia’s largest employer, the food manufacturing industry. We have households which need water, factories and mines which use it to produce goods for export and domestic use, power stations which need it to generate electricity. We have parks, gardens and ovals that need watering. And we have the rivers and plains themselves, with all their native species and farmed livestock, needing water.

The rivers helped build Australia’s prosperity. They have also shaped our national character. They embody the values of traditional aboriginal society, the pioneers who settled the countryside, the hard-working small communities that enabled it to prosper. They forged the deep love which so many of us feel for the Australian landscape and its unique plants and animals.

These are the values we need to discuss, as a community, as we try to work out what to do about our rivers and landscape.

Do we want a pristine ecosystem, but few jobs and little prosperity? Do we want short-term wealth but a desolate landscape and dead rivers? Can we strike a balance, somewhere in between?

The Murray’s backward flow reminds us that time is running out, both to have this discussion, and to start working out solutions. We need to talk to one another as a community, as we have never talked before.

At the moment we’re mostly yelling at one another – greenies, farmers, tourism operators, small communities, politicians. We’re not listening very well to one another’s needs and values. So, besides listening to what our landscape is saying, we also need to listen to each other.

There is no single, simple solution. The flow regimes in a great river, like the Murray or the Darling, are quite different in the upper, middle and lower reaches. The landscapes and industries that depend on those flows have differing needs. But every upstream action has a downstream consequence.

The river flowed backward and the Murray mouth may close in future, to the detriment of many communities and industries as well as the environment, because there is no longer enough water to go round. Eventually, Adelaide may find its water unsuited for domestic use.

Can we, as we have done in the grape industry, devise a way to get the same amount of production and prosperity with half the water? Can we teach Australians to be more sparing in their water use? Can we save and use the water that now flows to waste off roads and streets? Can we recycle water in our homes and cities? Can we water the bush and our farms more frugally, yet productively? Can we farm more native species profitably, because they suit the landscape and use less water?

The answer to all these questions is: "Yes, we can." The technology to achieve these things is either being developed, or else has been shown by science to be possible. There are many options.

Our rivers and landscape face a slowly-emerging crisis, and we need first to recognise that. But crisis also spells opportunity. It spells concerted action by governments, industries and communities. It spells resilience and imaginative solutions. It spells new roads to prosperity, arising out of the solutions we develop.

In barely 20 years one third of all the world’s people and nations will face severe water scarcity. If Australians can solve our challenge first, we can help them to solve theirs. Then we will have a more sustainable humanity on a more sustainable planet.