Water systems revealed in new Pilbara assessment project
A new study has delivered an unprecedented account of water resources in Western Australia’s Pilbara region, providing an in-depth understanding of local water systems and the potential impacts of climate change on water availability. The Pilbara Water Resource Assessment project, a A$3.5 million partnership between CSIRO, BHP Billiton and the Government of Western Australian, will allow water managers and local industry to plan for future water use in an area rich in resources and environmental assets.“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,” said CSIRO’s Dr Don McFarlane, the project leader. “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.”BHP Billiton said its contribution to the project reflected the Company’s commitment to responsible and sustainable water use at its Pilbara-based iron ore operations. “The study provided an opportunity to discuss our regional water resource key considerations and highlight the areas requiring further investigation,” said Blair Douglas, BHP Billiton Iron Ore’s Water Practice Lead. “The collaboration between industry and scientists in both the state and federal governments has delivered a comprehensive outcome. The fundamental science delivered by the study can be applied by industry to achieve practical and sustainable water management solutions.”The study revealed some of the mechanisms responsible for filling the Pilbara’s groundwater stores. It found that between 8 and 30 mmm of rainfall is required before runoff starts in most catchments, which leaks through streambeds to provide the main source of aquifer replenishment. Water from these shallow alluvial aquifers then recharges deeper paleochannels or dolomite aquifers, which can store large quantities of water in inland areas.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 over the past 23 years.The Assessment was funded by a A$0.5 million contribution from BHP Billiton and A$1.5 million each from CSIRO and the Government of Western Australia through the Royalties for Regions program. The research project was led by CSIRO and overseen by officers from the Department of Water, BHP Billiton, the Pilbara Development Commission and the Water Corporation.