"Water Corporation's frustration with Alcoa over Perth's drinking water aired in internal documents", 13 March 2026

Perth's water provider grew frustrated with US mining giant Alcoa after facing roadblocks in accessing areas near the city's key drinking water source that it needs to keep the supply safe, internal documents reveal.

There have long been concerns about Alcoa's bauxite mining operations edging closer to Serpentine Dam, a major drinking water source for the Perth metro area.

While there is no evidence that the city's water supply has been impacted, the Water Corporation holds serious concerns and has warned of the potential for a crisis.

US mining giant Alcoa will withdraw part of its plans to expand its mining operations in the world's only jarrah forests, following community concerns around water security and environmental impacts.

Documents recently released under Freedom of Information (FOI) laws to the WA Forest Alliance, and …, reveal further tensions between Water Corporation and Alcoa.

…, Water Corporation reported Alcoa had begun fencing off mine sites in the state forest, restricting ranger access, which "significantly diminished" its ability to monitor water quality near the dam.

In the same paper, it expressed frustration at roadblocks to information access through the Department of Water and Environmental Regulation (DWER).

Water Corporation said it had repeatedly requested data from Alcoa, including reports that detail significant chemical spills, drainage failures and other events that were "pertinent" to how the agency operates its dams.

"To date, this exchange of information has been limited," the document read.

Potential impact on Perth's water

Alcoa's operations span multiple public drinking water catchments, and the company has pledged a $100 million guarantee to help fund the government's response in the event of any impact to Perth's drinking water dams.

But the Water Corporation said that money was not sufficient to remediate a major pollution incident…

It warned the expansion of Alcoa's mining posed a heightened risk to the water supply, saying there was a lack of awareness within government of the dams' importance for reliability, energy use and costs to consumers.

… document showed the Water Corporation said the limited information it had received about Alcoa's management plans was insufficient to assess the potential impacts of future operations on the city's water scheme.

… An Alcoa spokesperson said the company was committed to responsible mining operations and worked "collaboratively with DWER to ensure safe and responsible water management".

US mining giant Alcoa is forced to pay $55 million after unlawfully clearing parts of a Western Australian native forest to mine bauxite.

That included "increasing separation distances between our operations and drinking water reservoirs and significant investment in enhanced water‑management practices," they said.

"We continue to strengthen our relationship with Water Corporation and established processes are in place to enable visibility of our current and planned mining activities and Water Corporation's ability to monitor water quality."…