Survey explores effect of climate change on Pilbara water

A study led by CSIRO has delivered an unprecedented account of water resources the Pilbara, providing an in-depth understanding of local water systems and the potential impacts of climate change on water availability.

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.

CSIRO project leader Dr Don McFarlane said the $3.5 million three year project between CSIRO, BHP Billiton and the State Government would allow water managers and local industry to plan for future 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 responsible for filling the Pilbara's groundwater stores.

It found that between 8 and 30 millimetres of rainfall is required before runoff starts in most catchments, which leaks through streambeds 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 over 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 CSIRO and the State Government 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.