This article has been updated – see below

One of Australia’s most pristine national parks could be under serious threat from Rio Tinto’s Pilbara mining operations.

The Karijini National Park is one of the most spectacular in Western Australia, with gorges, chasms and rockpools and waterfalls fed by groundwater. However, the park abuts a number of major Pilbara mining operations and their thirst for water has been causing growing problems throughout the region for well over a decade.

Now sources inside Rio Tinto have told Crikey the company’s mining operations have breached the water table beneath the national park, potentially contaminating the aquifer.


The revelations come at a sensitive time for Rio. Its subsidiary Hamersley is on the verge of securing approval from the WA government to expand its Marandoo mine — which is physically inside the national park — beneath the aquifer. Marandoo was approved in 1992 on the basis that it only operated above the aquifer.

Following hydrological testing of the aquifers in the region (there are two; the water in the national park is from the shallow one), in 2007 Hamersley began a lengthy process to obtain approval to expand the mine below the level of groundwater in the area. The WA Environmental Protection Authority in April released a report recommending Hamersley be permitted to proceed, subject to conditions. The WA Environment Minister Donna Faragher has yet to make a final decision.

Marandoo, almost in the shadow of Mt Bruce and 35 kilometres north-east of Tom Price, was carved out of Karijini National Park by the Lawrence government in 1991. A specific condition imposed by the then-government was that “there shall be no unacceptable impact on the conservation values of the Karijini National Park resulting from groundwater abstraction associated with the project, particularly the coolibah woodlands to the east of Mt Bruce”.

Mining operations in the region are heavily dependent on groundwater, both for mining use and for town water supplies. The whole region is under permanent water restrictions, and the WA government recently released a 20-year water strategy for the region. The mining boom means even greater stress on water resources already at the limit of supply. There is talk that groundwater supplies are being rapidly used up even as the region spruiks its growth credentials.

The stress caused by reliance on groundwater has been showing in the region for years. WA Greens MLC Robin Chapple told Crikey he tried to alert the then-WA government to the impact of groundwater extraction in the region in 1990s, when the floor of the Southern Fortescue valley, west of Marandoo, had sunk several metres and large, fissure-like sinkholes had started to appear. Sinkholes can occur naturally. However, more recently, the National Park itself has started to witness subsidence and sinkholes.

In 1999, the WA Department of Conservation and Land Management reported that five sinkholes had appeared in the Tom Price Bore Fields on the edge of the park. We ran a tip nearly three years ago that contractors were being dispatched by Hamersley into the park itself to erect fences around new sinkholes. The same tipster recently contacted Crikey to say that, three years on, contractors were regularly being sent into the park to fence off sinkholes up to 50 metres wide and 15 metres deep.

Rio Tinto claims it has “a framework for addressing water related business risk and improving performance, and we focus on ways to minimise the amount of water we remove from the environment”. In 2008 and 2009 it produced sustainable development reports for its iron ore operations the previous year. In neither report was Karijini mentioned other than casually.

Both reports showed rocketing water use in the company’s Pilbara operations, with freshwater per tonne railed increasing by 45% between 2005 and 2008 (to its credit, however, Rio does a far better job than Pilbara rival BHP Billiton of reporting its water usage).

Greens senator Scott Ludlam has written to Rio Tinto’s Sam Walshe asking for a response to the claims about interference with the water table.

The national park might be the short-term victim of the miner’s ever-greater thirst for water in the region, but the whole Pilbara mining industry is under threat from its own unsustainable consumption.

Rio Tinto was asked to respond on these issues but did not do so by deadline.

Update: Rio Tinto spokesman Gervase Green provided a response to Crikey’s question shortly after deadline

The company’s sustainable development reports do not discuss Karijini National Park directly but do show that the company’s iron ore-related consumption of water (even per tonne railed) has increased very significantly since 2005. What plans does the company have to curb this increase?

Water is extracted from licensed borefields across the Pilbara, and feeding into domestic use in the several towns across the area, as well as mining camps and operational use (such as dust suppression) at our mines. Certainly 2008 was a dry year, with increased town consumption and late season rains leading to higher extraction. Apart from that, our consumption per tonne has been quite flat for several years, and is currently at less than 2007/08 levels. Rio Tinto takes its responsibilities seriously and employs water conservation strategies (including maximising recycling) to reduce consumption where possible.

Can the company confirm that Hamersley Iron has sent contractors into the Karijini National Park or to locations close to the Park at various times in the last 3 years to fence off sinkholes – in which case, how often, and has the company undertaken any work to identify the causes of the sinkholes (which can occur naturally as well as as a result of groundwater depletion)?

Not recently, though prior to 2007 we did place some temporary fencing around sinkholes where we felt a safety was a concern – notably if difficult to see while driving. The modest fencing was a precautionary measure, and if near the National Park was done with the full knowledge of appropriate officials.

Have there been any recent events in the company’s Pilbara operations involving contamination or some other interference with either the lower or higher aquifer (I understand there are two) beneath or adjacent to the Karijini National Park?

No. All our borefields are monitored, and the results are followed by the Department of Water (and subject to separate verification). This level of assuredness is important, as the extracted water contributes to town domestic supply.

Peter Fray

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