Hills water still a valuable resource: CSIRO expert
Released 16 Oct 2008
One of the nation's leading water experts yesterday told a group of WA's top water professionals that the Perth Hills area was still the cheapest and most energy efficient source of water for the capital city – and further scientific work should continue to better manage the effects of climate change on its yield.
Dr Tom Hatton, Director of CSIRO's Water For A Healthy Country Flagship, said evidence was starting to show of a shifting relationship between rainfall and run-off into dams around the nation, and it was one area of scientific and water management concern shared between Western Australia and the East Coast states reliant on the Murray-Darling Basin.
"We are tackling this problem in the South East of the country in the studies we have been asked to undertake for the Murray-Darling Basin," Dr Hatton said.
"In those analyses, the drought in terms of low rainfall is not entirely unique; it has happened twice before, more or less of this magnitude.
"What is different is that run-off from that rainfall is now much less.
"We still cannot entirely explain the reduction in run-off efficiency," he said.
Dr Hatton said this was one example of how potential climate change had somewhat changed the goalposts for scientific modelling for water resources.
The relationships between rainfall, run-off and salinity were always assumed to be constant, but new evidence challenged this assumption, he said.
"The empirical rules of thumb we developed over time to manage our surface water supplies were constant – and what we face now is that these may no longer apply," Dr Hatton said.
Dr Hatton was addressing the state's leading water professionals and researchers at the Surface Water Is Not Dead seminar hosted by the Department of Water.
He said climate scientists needed to agree on a robust method to narrow down the uncertainty in future climate projections.
This should include enhanced monitoring of catchments as in the case of WA, the Perth hills were still the cheapest source of potential water for the Perth IWSS and should not be abandoned.
Department of Water director general Kim Taylor welcomed the comments, and the partnerships between CSIRO and state agencies in this area.
"There is current research by the CSIRO, which is investigating the role of changes in catchment vegetation versus climate change so we can get a better understanding of the impacts on streamflow," Mr Taylor said.
"The project combines understanding the importance of tree water use and balance intensive monitoring of vegetation characteristics and water balances in selected catchments across a wide range of sites with different climates and vegetation management.
The CSIRO project, and important work being undertaken by the Department of Water, will improve the modelling of how forested catchments may behave in the future, Mr Taylor said.
"We can then extend the results from the selected research sites to the major Darling Range catchments and adopt improved catchment management for both water yield and ecological sustainability," he said.
"With respect to improving yields from current water supply systems, there are also current research programs in the Wungong catchment, which are trialling a range of catchment treatments and measuring water and biodiversity outcomes," he said.
Surface water remains a critical part of Western Australia's available water resources, Mr Taylor said.
Contact: Peter Collins
Phone: (08) 6364 6848 / 0434 603 441