Conservationists have declared victory in a fight over Tasmania’s Takayna/Tarkine rainforest after a judge ruled the Morrison government was wrong to approve preliminary work on a mine tailings dam.
Federal Court Judge Mark Moshinsky found then Environment Minister Sussan Ley had failed to apply the precautionary principle before allowing drilling and surveying work for a new tailings dam near the city of Rosebery, on the west coast of the state.
In a ruling on Monday afternoon, Moshinsky said a January decision by an environment department official representing Ley had failed to consider whether the works would cause serious or irreversible damage to Tasmania’s masked owl habitat , endangered.
The justice gave no immediate order, but noted that the approval will likely be set aside. This could mean that mineral company MMG’s proposal would need re-evaluation under national environmental laws.
The Bob Brown Foundation said the ruling was one of the most significant in environmental law since the Environmental Protection and Biodiversity Conservation Act was introduced in 1999, as it showed that the precautionary principle when the effects of a proposed development were unclear.
The foundation’s campaign manager Jenny Weber said the masked owl, which is listed as endangered in Tasmania and believed to be down to around 500 breeding pairs, “was not taken seriously account at all” in the approval decision.
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“This decision tells miners, loggers and other big project proponents that they can no longer profit from the uncertainty that follows a lack of quality scientific research,” he said.
Neither MMG nor the Tasmanian government, which is a staunch supporter of the development, had responded to Guardian Australia before publication.
The validity of federal approval of the drilling and roadworks was already in question after Ley agreed before the election that there were grounds for a formal reconsideration. Responsibility for this process was handed over to the new Environment Minister, Tanya Plibersek, after Labor won the election. She still has to make a decision.
Bob Brown, the former Greens leader who started the foundation, said the judgment was huge and would strengthen Plibersek’s hand “to defend threatened species from the Tarkine to Cape York to the Burrup Peninsula”.
He said the Commonwealth should compensate nearly 100 protesters who had been arrested while campaigning against the development.
In a statement Tuesday morning, Plibersek said the legal action relates to a decision made under the previous federal government, that he had been notified of the ruling and would consider it in detail.
The Chinese-owned company says a new tailings dam is needed to extend the life of its 85-year-old Rosebery zinc, copper and lead mine. If the dam is approved, the company plans to clear up to 285 hectares, roughly the equivalent of 350 football fields, of rainforest and other land for the dam and a 3.5 km pipeline that would carry waste toxics from the mine through the Pieman River.
The Bob Brown Foundation says crossing the river would place the tailings dam within the Tarkine, an environmentally diverse area that the Australian Heritage Council 10 years ago recommended should be protected. He says there are other options open to MMG.
The judge reserved his orders until a hearing scheduled for later this week.