Science Blog

Australian water: Self inflicted wounds?

Professor Charles Vörösmarty, Institute for the Study of Earth, Oceans and Space, University of New Hampshire (USA)
31 August 2007

Charles Vörösmarty is Director of the Water Systems Analysis Group at the University of New Hampshire’s Institute for the Study of Earth, Oceans and Space in the US. He is an expert on the impact of climate change and water use on global water resources and the development of global indicators of water stress. He was appointed a member of the National Arctic Research Commission by US President George W Bush and co-chairs the Global Water System Project representing more than 200 international scientists, headquartered in Bonn, Germany.

Vörösmarty joined more than 60 scientists at South Stradbroke Island in Queensland this week to discuss the scope and implications of humans interacting with their rivers, watersheds and water resource systems. The Third International Symposium on Riverine Landscapes (TISORL) unites Australian perspectives with those from around the world and is co-sponsored by the Global Water System Project. TISORL is convened by the Australian Rivers Institute at Griffith University.

It is easy to recognize the multiple roles that water plays in supporting our way of life by providing a critical input to the agricultural, industrial, and domestic sectors. What is less well-known are the major and in many cases irreversible impacts imposed on the aquatic environment as we try to assure a steady supply of fresh water to society.

We derive important and free ecosystems services from well-functioning watersheds and waterways, like fish in our diet, erosion control, navigation, pollution processing, and buffering from climate extremes like flood and drought. Maintaining healthy ecosystems means maintaining the well-being of humankind. Yet, throughout the world, we place into jeopardy the very existence of rivers, lakes, and wetlands.

There is mounting scientific evidence that across large swaths of the planet we are acting as poor custodians of our freshwater resources and live well beyond our "water means" --depleting river flow, polluting streams and lakes, draining down limited groundwater stocks, destroying wetlands that provide flood control, wiping out critical spawning grounds for fish….the list goes on and on.

These consequences feedback directly to our economies, either as repair costs to the environment or replacement costs for services that used to be supplied by nature. On economic grounds alone, many of the demands we make of the water system will ultimately need to be rethought.

The recent and severe drought in Australia provides an ideal opportunity to think creatively about meeting these many challenges. While "silver bullet" engineering solutions, like construction of a large reservoir or massive expansion of agriculture into the water-rich North of the continent, may have some appeal when the skies in the south aren't producing much rain, history provides many examples of how these plans are often turned upside down by prohibitive cost or the inability of the local environment to accommodate these new activities for which it is not well-adapted.

Dams surely can serve as an important supply of water during times of drought, but filling reservoirs while simultaneously failing to institute wise use practices and efficiency gains makes little sense. But dams also bear costs on aquatic ecosystems by blocking migratory pathways, creating stressful thermal changes to rivers, and trapping sediments that are essential to the stability of coastal landforms where many of us live.

As for major interbasin transfers, one would need to carefully question the wisdom of moving water huge distances and at huge energy and economic costs -- $20 per cubic metre in the case of the Western Australian north-south water transfer -- when water-saving technologies deliver the commodity at a mere fraction of the cost.

The water situation in Australia is symbolic of some of the very same challenges and choices besetting water providers and users across the world. Many of the damages are self-inflicted and could be avoided with smart solutions that combine engineering and natural ecosystem services.

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