Water security in Western Australia is entering a new era. The Cook Government’s recent Memorandum of Understanding (MoU) with Rio Tinto to expand desalination infrastructure in the Pilbara is more than just a corporate-government deal—it’s a direct response to climate pressures, Indigenous concerns, and the ongoing demand for sustainable industry growth.
While the agreement primarily targets the West Pilbara Water Supply Scheme (WPWSS)—which services Karratha, Dampier, Wickham, Roebourne, and key industrial sites like Cape Lambert and the Burrup Peninsula—its ripple effects will be felt across WA. From ensuring long-term industrial sustainability to protecting Indigenous water rights and setting a precedent for future desalination efforts, this initiative is one of the most significant water projects in the state’s history.
Why This Matters to WA
For many Perth residents, news about Pilbara water security might seem distant. After all, we’re not turning on our taps and expecting water from Karratha or Roebourne. But what happens in the Pilbara doesn’t stay in the Pilbara—it has profound implications for WA’s economy, environment, and Indigenous relations.
The Pilbara is the heart of WA’s mining sector, producing the bulk of the state’s iron ore exports—an industry worth over $136 billion annually. This sector is heavily reliant on water, not just for dust suppression and processing but for sustaining the regional workforce and towns that keep these mines running. Ensuring reliable water access means ensuring stability in one of WA’s biggest economic engines.
At the same time, concerns from Traditional Owner groups such as the Yindjibarndi and Robe River Kuruma people highlight how water abstraction threatens sacred sites and cultural heritage. Over-extraction of groundwater from aquifers, particularly at Bungaroo and Millstream, risks permanently damaging Indigenous lands, which have already suffered from past industrial encroachments—including Rio Tinto’s infamous destruction of Juukan Gorge in 2020.
Then there’s climate change. WA’s north has faced five consecutive years of below-average rainfall, leading to reduced groundwater recharge at Millstream and Bungaroo borefields. Harding Dam, a key surface water source, has seen declining runoff, exacerbating long-term supply challenges. This pattern mirrors the broader water crisis in southern WA, where declining rainfall has already led Perth to rely on desalination plants for nearly half of its drinking water.
A Closer Look at the New Desalination Strategy
Rio Tinto’s commitment to developing a seawater desalination plant at Dampier’s Parker Point operations is a major step in reducing reliance on groundwater. Here’s how the plan is expected to unfold:
Stage 1 (Operational by 2026): Producing 4 gigalitres (GL) of desalinated water per year, significantly reducing groundwater extraction from Bungaroo borefield.
Stage 2 (Proposed for 2027): A potential second expansion adding another 4GL per year, pending feasibility assessments with Water Corporation.
Long-Term Solution (By 2030): The Water Corporation plans to construct a large-scale desalination plant, allowing Rio Tinto to phase out groundwater abstraction entirely.
Together, these projects will help ensure a climate-independent water supply for the region while mitigating environmental damage from aquifer overuse.
How This Compares to Past WA Water Projects
WA has turned to desalination before as a way to combat drying climates. Perth’s first desalination plant, the Perth Seawater Desalination Plant, was built in 2006 and now supplies 15% of the city’s water needs. The Southern Seawater Desalination Plant, operational since 2011, provides around 100GL of drinking water per year, accounting for roughly 20% of the city’s supply. Combined, desalination has allowed Perth to maintain water security despite a decline of over 20% in long-term average rainfall since the 1970s.
In the mining industry, desalination has also proven essential. Alcoa’s Wagerup refinery built a brackish water desalination plant in 2009 to reduce reliance on the Yarragadee Aquifer. Similarly, in Chile—one of the only other major iron ore producers on par with WA—mining companies have shifted toward desalination to meet their water needs while reducing ecological damage to aquifers.
However, large-scale desalination is not without its challenges.
The Challenges and Concerns
Cost and Energy Use
Desalination is expensive. Producing potable water from seawater requires about 4 kWh per kilolitre—roughly four times the energy cost of groundwater pumping. With rising electricity prices, ensuring these plants operate on renewable energy will be critical to avoiding emissions increases.
Environmental Risks
Brine disposal is one of the most significant environmental concerns. Desalination plants extract freshwater while discharging concentrated salt back into the ocean, potentially disrupting marine ecosystems. While modern desalination facilities use diffusers to minimize impact, sustained increases in brine discharge in sensitive marine environments like the Dampier Archipelago could create long-term ecological risks.
Indigenous Consultation and Cultural Protection
While reducing groundwater extraction is a positive step, many Traditional Owner groups remain skeptical of mining companies’ environmental commitments. The destruction of Juukan Gorge by Rio Tinto in 2020 severely damaged the company’s relationship with Indigenous communities. Although the company has since committed to stronger cultural heritage protections, skepticism remains. There is currently no explicit funding for Indigenous-led water monitoring programs, raising concerns that Traditional Owners may still be left out of long-term water governance discussions.
Timelines and Feasibility Risks
Large-scale infrastructure projects often face delays and cost overruns. While Stage 1 of the Dampier desalination plant is planned for 2026, its completion depends on Rio Tinto’s Parker Point upgrades, and Stage 2 remains in a feasibility phase. WA has seen major water projects face setbacks before, including delays in the expansion of the Southern Seawater Desalination Plant.
What’s Next for WA’s Water Security?
Beyond the Pilbara, WA’s reliance on desalination is set to grow. With climate change continuing to drive long-term drying trends, future water strategies will likely include:
More desalination plants: The Water Corporation has proposed a third desalination plant for Perth near Alkimos, expected to be operational by 2028.
Better water recycling: Expanding Perth’s Groundwater Replenishment Scheme, which injects treated wastewater back into underground aquifers, could further reduce reliance on desalination.
Renewable-powered desalination: As WA expands its renewable energy grid, integrating solar and wind power into desalination operations will be essential to maintaining cost-effectiveness and sustainability.
For the people of Perth and WA, this means water security will remain a critical political and economic issue in the coming decades. As mining, agriculture, and urban development continue to compete for limited resources, proactive investment in climate-independent water solutions will determine the state’s long-term resilience.
Final Thoughts
The Cook Government’s agreement with Rio Tinto represents a necessary shift in WA’s approach to industrial water use. By reducing reliance on groundwater and investing in desalination, the Pilbara’s industries and communities are positioning themselves for long-term sustainability. However, the success of this initiative will depend on transparent environmental protections, renewable energy integration, and meaningful engagement with Traditional Owners.
With WA’s future water challenges only growing, this project could set the standard for how the state manages its most precious resource in the years ahead.
