Australia's Leading Tropical River Scientists Reject Kimberley-Perth Canal
10 Feb 2005
The future of Perth's water supply and the health of nationally important rivers in the Kimberley rests with Western Australia choosing the science-based National Water Initiative over a hasty approach in the heat of an election, according to Australia's most eminent tropical river scientists.
All Australian water resource developments now have a powerful framework for their evaluation in the National Water Initiative (NWI). The Initiative is designed to ensure the health of river and groundwater systems, sustain rural and urban communities, and increase productivity and efficiency of water use.
The Australian Tropical Rivers Group, convened by WWF-Australia, said preliminary analysis already shows the proposed canal would severely degrade Western Australia's biggest river.
"It would be a tragedy if we missed the opportunity for WA people and all Australians to insist that both parties adopt the NWI and submit their solutions to solving Perth's water problems to the scrutiny of the initiative's agreed principles," John Williams, a member of the Australian Tropical Rivers Group, said yesterday.
"Without NWI, Western Australia will commit to ill-conceived expenditure that will shackle us to enormous economic and environmental costs for decades into the future.
"It also puzzles us why it can be assumed that water in the tropics is not best used by the people living in the tropics. It is their water and a vital resource on which to build their future. The water is not wasted," Dr Williams said.
The Australian Tropical Rivers Group is calling for comprehensive examination within the principles of the NWI for this and all water resource developments proposed for tropical rivers - initial analysis already suggests the canal would drain water from the river during the dry season when it was just a trickle.
The proposal by engineering contractor Tenix to extract two per cent of average annual flows from the Fitzroy ignores large year-to-year differences in river flows.
"The water just isn't there during the dry season. The Fitzroy River is a boom-and-bust ecosystem. For nine months of the year it is a trickle, a series of pools only," Professor Peter Davies, a member of the Tropical Rivers Group and noted expert on the Fitzroy, said.
"Over the long term, pumping water from the underground aquifer can be the same as pumping water straight from the river. Dangerously little is known about the rates and pathways for water movement between underground aquifers and the Fitzroy itself."
A 1993 report prepared for the WA Government estimated the volumes of aquifers near Fitzroy Crossing at not much more than 200 gigalitres. Pumping 200 gigalitres each year would mine the aquifer and cause serious environmental damage.
"Taking out 200 gigalitres a year would pump the river dry in drought years. Total annual flows at Fitzroy Crossing have fallen below 400 gigalitres four times since 1958, and close to 200 gigalitres once," Professor Davies said.
"Pumping out 200 gigalitres would remove over 50 per cent of total river flows in those years, not 2 per cent as claimed.
"Guaranteeing 200 gigalitres each year would most likely require the Fitzroy to be dammed, which would severely degrade the river and its rich aquatic life."
The Fitzroy is Western Australia's largest free-flowing river. Its major floodplains meet criteria for listing as being internationally important under the Ramsar Convention on wetlands. Sixty-seven species of waterbirds totalling 38 500 individuals have been recorded on the Camballin floodplain along the Fitzroy.
River pools are called "living water" by local Aboriginal communities who rely on them and who have strong cultural ties to the river. Twenty-nine species of freshwater fish, including barramundi, are known from west Kimberley rivers. This is equal to the number in the whole Murray Darling Basin. Fish rely on river pools as refuges in the dry season (April - December). Freshwater sawfish and whipray are known to occur there, which are listed on the international threatened species list by IUCN - the World Conservation Union.
Downstream, fish stocks and fishermen in King Sound are also likely to be affected.
Best practice resource management means analysing all aspects; including land and water, energy use, cultural values and economics.
"All of these important issues need full and comprehensive examination to make sure that we move beyond the era of making resource decisions that become economic and environmental burdens for generations to come," Professor Davies said.
The Australian Tropical Rivers Group is an independent group of Australian researchers. This statement reflects the collective views of the members of the group based upon their extensive research experience and knowledge of river ecology and Northern Australia.
Its members are:
- Professor Angela Arthington, Centre for Riverine Landscapes, Griffith University, Brisbane
- Professor Stuart Bunn, Director, Centre for Riverine Landscapes, Griffith University
- Professor Peter Davies, Director, Centre of Excellence in Natural Resource Management, University of Western Australia
- Dr Max Finlayson, National Centre for Tropical Wetlands Research, Darwin
- Professor Stephen Garnett, Professor of Tropical Knowledge, Charles Darwin University
- Professor Arthur Georges, Director, Applied Ecology Research Group, Uni of Canberra
- Professor Richard Kingsford, School of Biological, Earth and Environmental Science, University of NSW
- Professor Richard Pearson, School of Tropical Biology, James Cook University
- Professor Robert Wasson, Deputy Vice-Chancellor Research, Charles Darwin University
- Dr John Williams, Former Chief, CSIRO Land and Water, and member of The Wentworth Group of Concerned Scientists.
- Dr Stuart Blanch, Convenor and WWF Fresh Water Manager
Read the Group's statement Securing the North: Australia's Tropical Rivers.
For further comment contact:
Jacqueline McArthur, WWF Press Office: 0408 626 780, 02 8202 1242
