Water systems revealed
■ An unprecedented account of the water resources of the Pilbara, providing an in-depth understanding of local water systems and the potential impacts of climate change on water availability, has been revealed by a CSIRO study.
The Pilbara Water Resource Assessment area examined surface water and groundwater resources, and their environmental significance on the Ashburton-Robe, Upper Fortescue, Lower Fortescue Hedland and De Grey-Canning catchments.
CSIRO project leader Dr Don McFarlane said the $3.5 million three-year project between the CSIRO, BHP Billiton and the State Government would allow water managers and local industry to plan water use.
“Knowing how the water systems operate right across the region, such as how groundwater is affected by rainfall and storm events, helps with the planning and management of local water use,” he said.
“By helping to put a lot of smaller local water resource investigations into a broader context, this study provides a strong framework for water managers and local industries well into the future.”
The study revealed some of the mechanisms that filled the Pilbara’s groundwater stores.
It found that between 8mm and 30mm of rainfall was required before run-off started in most catchments, which leaks through stream beds to provide the main source of aquifer replenishment.
It also examined how ecosystems dependent on the region’s groundwater sources have changed as a result of wet and dry periods, finding they expand during wet periods and contract during dry periods, but have remained relatively stable in number in the past 23 years.
BHP Billiton Iron Ore’s water practice lead Blair Douglas said the fundamental science delivered by the study could be applied by industry to achieve practical and sustainable water management solutions.
“The study provided an opportunity to discuss our regional water resource key considerations and highlight the areas requiring further investigation,” he said.
The assessment was funded by a $500,000 contribution from BHP Billiton and $1.5 million each from the CSIRO and the State Government through the Royalties for Regions program.
The research project was led by the CSIRO and overseen by the Department of Water, BHP Billiton, the Pilbara Development Commission and the Water Corporation.