Land and Water Link

November 2003

Local communities, irrigators, scientists and governments are all trying to come to grips with how best to manage the River Murray, now and into the future. The fundamental issues revolve around the amounts of water available for multiple uses – for our towns and industries, for irrigation, and for the life of the river itself.

Our challenge is to take into account the many interests at stake and to engage all parties in reaching decisions based on social considerations, economic costs and environmental benefits. Scientific evidence is an important input to this decision making process.

Comprehensive research on the state of the Murray involves an interconnected series of results and environmental indicators for the entire system. This means that the river report card is more complex than a one-line entry on the ledger or a salinity scorecard from one location along the river.

A Healthy Murray Needs More Water

The need to return more water to the Murray River is not based on its salinity levels. There is simply not enough water to support the flow regimes that nurture habitat for the plants and animals of the river, floodplains and wetlands.

Irrigation is a major source of wealth and well-being in regional Australia. The recent National Land and Water Resources Audit estimated that irrigated agriculture produces about 50% of our agricultural profit. But in achieving this, we are extracting too much water from the Murray-Darling.

On average over the last ten years, nearly 80% of the Murray’s natural flow has been diverted for irrigated agriculture and urban use. Not only does the river system have less water, it is also battling boosted sediment, nutrient, salt and pesticide levels as a result of our farming and land use. Together, these factors place the health of the river under increasing stress with long-term consequences for water quality.

Dying river red gums, declining native species and degraded wetlands are a litmus test for the river’s deteriorating condition. Half of the native fish species in the Basin are threatened with extinction. Murray crayfish, river snails and river mussels are now extinct in the lower Murray.

Timely Action Can Avert Future Damage

Reduced salinity levels in the lower Murray have been heralded as one of the positive outcomes in recent years. But this result needs to be seen for what it is – a tribute to what can be achieved when communities and governments invest in long-term action based on sound research.

Some twenty years ago scientific warnings were heeded, leading to an ambitious range of salinity mitigation measures under the Murray-Darling Basin’s Salinity and Drainage Strategy. These included salinity action plans and a series of salt interception schemes that now divert over 1100 tonnes of salt per day away from the Murray, with a direct payoff for salinity levels at Morgan.

More to the Salinity Story

Taking a long-term outlook, salinity presents a real and ongoing threat. CSIRO studies show that stream salinity from dryland catchments is increasing, particularly on the western slopes of NSW. Over the next 50-100 years with existing land use, groundwater rises will flush more salt from the landscape, overriding the benefits gained through existing salinity mitigation measures.

The fact that we can expect to see rising river salt loads should be a concern given that salinity levels at Morgan exceeded World Health Organisation (WHO) guidelines for 20% of the time over the period 1980-2000.

So, although engineering interventions like groundwater interception schemes have bought us additional time by treating the symptoms, we have done little to slow the causes: dryland salinity in the catchments, saline groundwater discharge into the floodplain and small dilution flows.

Long-term solutions will require changes to land use. Ultimately, we need more options that generate rural wealth and yet prevent salt from being mobilised and moved towards our rivers and lower points in the landscape.

Solutions for the Murray

Solutions for the Murray and the communities and industries that depend on the river will be no less complex than the underlying problems. We now know there is no single or quick fix.

Nor is this an ‘either or’ situation. It isn’t a case of choosing between agricultural use or environmental flows. We know from past experience that the symptoms we first detect in sick wetlands and rivers will inevitably spread – affecting water supplies, agricultural viability, and tourism and recreation values.

In the end – however many gigalitres of water are returned to refresh wetlands along the Murray – other actions, responses and incentives will be required in order to deliver long-term improvements and sustainable outcomes.

These are likely to include better flow management scheduling, structural and operational improvements, effective water trading systems, more efficient water use and greater investment security for irrigators.

In tackling this issue, irrigators have a pivotal role as prime users of the resource base that underpins their livelihood, and which contributes around $10 billion a year to Australia’s agricultural wealth.

I am heartened by my frequent discussions with farming and irrigation groups. As farmers, rural communities and scientists work together towards solutions that serve both productive and environmental outcomes, I see a real commitment to embrace innovative land and water management practices.

Let’s hope that by taking a long-term view and acting soon, we can look back in twenty years time on decisions that delivered positive and lasting outcomes for all river uses.