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Dam it all? River futures in northern Australia

Posted on August 19, 2013

Yesterday in Darwin, Australia, the country’s Prime Minister announced his plan for northern Australia. He called for a “national imagination” to take advantage of the “enormous agricultural potential” of the Top End, including harnessing the “bountiful supply of water”.

The diverse rivers of Northern Australia, flat and expansive, support diverse species and are linked by unregulated Wet season flows. Credit: Andrew Campbell

The diverse rivers of Northern Australia, flat and expansive, support diverse species and are linked by unregulated Wet season flows. Credit: Andrew Campbell

He then travelled to Kununurra to stand on the wall of Australia’s largest dam and further discuss a one-third expansion of the Ord River Irrigation Scheme. His focus included “natural resource development in liquefied natural gas, mining and agribusiness” – some key users of water – with little mention of truly utilising natural advantages of the north.

The tropical rivers of northern Australia are murky and organic, painted in a palette of vivid greens and milky browns that fluctuate with seasonal monsoons and rushing tides. They reflect the stifling, blinding sky that lies hot and humid over the savannas for months on end. They support a highly-endemic fauna and are often described as strongholds of biodiversity. In many ways, these waters act as a metaphor for life in the tropics – bright and beautiful, yet dynamic and demanding.

As pressure to develop the North mounts, these river systems are likely to become far more contested. As a nation, we have witnessed similar clashes between commodities, communities and conservation in the Murray-Darling Basin. As scientists, we have documented the effects of water extraction on floodplains,fish and forests.

As farmers, we have experienced diminishing terms of trade and a transition away from the traditional family farm. As taxpayers, we have funded a multi-billion dollar rescue mission aimed at improving river health.

Now, staring down the barrel of a decade of rapid transformation, we confront a critical decision: “Is this a future we want to repeat in northern Australia?”

Dam-nation

The Prime Minister’s announcements echoed the European-derived understanding of rivers that was used when settling the Murray-Darling Basin. There, early decisions to allocate water for agricultural progress were made implicitly – water licences were handed out and the system quickly became over-allocated. As consumptive capacity was taken up, ecological decline accelerated and “fitful, reluctant co-operation” in water management began.

Today, despite concerted efforts to move towards adaptive frameworks, we still don’t know if the system will recover from the tampering.

Most grand schemes for development in northern Australia fail to adopt what has been learnt in the south. Earlier this week on The Conversation, my colleagues discussed the formidable climatic, physical and economic constraints to expanding conventional irrigated agriculture in northern Australia.

In my experience, as an aquatic ecologist, calls to harness regional waters are typically code for dam building. It will be interesting to see to what extent both the detail of the Prime Minister’s plan and the Coalition’s yet-to-be-released Dams and Water Management Discussion Paper will rely upon new dams.


Damming of Australia’s rivers has been largely restricted to southern states. What will this map look like in 2030? Data: Geoscience Australia 

We know that dams damage rivers – there are literally hundreds of scientific studies detailing effects on connectivity, water quality and biodiversity. It is odd that, at a time when people elsewhere are discussing dam removal, we might want to build more.

There are already more than 820 dams in Australia, with a total capacity exceeding 91,000 gigalitres (or 183 Sydney Harbours). Most are at southern latitudes, where Mediterranean climates mean we want for water storages that will last through dry summers. Less than 10% are located in northern Australia.

However, it does not necessarily follow that the continent somehow needs to be “evened-up” with more dams in the north. There are very good reasons why there are so few dams in that part of the country, including the lack of suitable sites and that the water is already being used.

What’s so different about northern Australia, anyway?

Many argue that the north is different. Certainly, it is geographically isolated, dominated by weather and climate, populated by ancient cultures, supported by a transient workforce and underpinned economically by extraction of mineral resources. When it comes to environmental vulnerability, however, this difference may be less pronounced.

Many of the top-ten environmental issues faced by thecontinent, “water” being number one, are unconstrained by latitude and are also prevalent here. In any case rivers need water, and river managers need science.

Scientists working in northern Australia have a strong track record producing comprehensive data informed by meaningful engagement with local stakeholders including Traditional Owners. The Tropical Rivers and Coastal Knowledge (TRaCK) collaboration and the new Northern AustraliaMarine Biodiversity and Environmental Decisions hubs under the Commonwealth’s NERP program, have dramatically improved our understanding of northern rivers.

We now know how flows link key habitats, facilitate life cycles of migratory fish (including the iconic Barramundi), drive food web dynamics and generate valuable ecosystem services and social values. My own research applies next-generation molecular technologies to detect fragments of DNA in the water column to better understand complex food chains and also detect rare species.

Much has also been written on how society might use this understanding to inform development of water resources. Whether or not that advice is acted on will be critical in determining the success of the water management process and the future health of our northern rivers.

Australia needs refined approaches, not decision making governed by rules of thumb. We need practices that hard-wire feedbacks between aspirational objectives, practical operations and monitored outcomes.

Critically, whatever the role of rivers, we must shake the pervasive, stubborn persistence to make northern versions of southern mistakes.

In the words of the Nobel Prize winning philosopher George Santayana: “Those who cannot learn from history are doomed to repeat it.”

Source: The Conversation, story by Tom Rayner

   
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