Rio Tinto and WA Government double desalination capacity

Written by Isaac FrancisPublished Mar. 4 2026Last Updated Mar. 4 2026

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The Western Australian Government and mining titan Rio Tinto (ASX:RIO) have committed to doubling the capacity of the $1.1 billion Dampier seawater desalination plant.

The agreement marks a pivotal shift in managing the West Pilbara’s strained resources, as the region grapples with a drying climate and intensifying industrial demand.

Construction on the project’s second stage is already underway, following a rigorous period of negotiation between Rio Tinto and the Water Corporation to address long-term feasibility and cost-sharing.

The expansion comes as a direct response to mounting pressure on the Millstream and Bungaroo aquifers, which have suffered from rainfall levels consistently below the long-term average over the last five years.

The underground reserves currently anchor the West Pilbara Water Supply Scheme, servicing the communities of Karratha, Wickham, and Dampier, alongside the critical industrial hubs of the Burrup Peninsula.

With approximately 78% of the state’s potable water currently sourced from groundwater, the transition to desalination is viewed as a vital environmental safeguard.

Premier Roger Cook emphasised that this multi-million-dollar investment will "deliver billions of litres of water to local households and businesses," while Rio Tinto’s iron ore chief, Matt Holcz, reaffirmed the company's commitment to reducing its reliance on groundwater extraction.

The first 4-gigalitre phase is slated for completion in late 2026, with the newly announced second phase expected to provide an additional 4 gigalitres by 2027.

Rio Tinto and WA Government double desalination capacity

Frequently asked questions

Why did Rio Tinto (ASX:RIO) and the WA Government decide to double the Dampier desalination plant capacity?

What is the expected timeline for the Rio Tinto (ASX:RIO) desalination project?

How does this water agreement impact Rio Tinto’s (ASX:RIO) ESG profile?

What are the key industrial hubs supported by the Dampier desalination expansion?

What are the main capex and cost-sharing implications for Rio Tinto (ASX:RIO)?

Is the Dampier desalination expansion a bull or bear signal for Rio Tinto (ASX:RIO)?

How does this project change the investment thesis for Rio Tinto (ASX:RIO) in Western Australia?

What are the key risks associated with the Dampier desalination project expansion?