The Environmental Protection Authority approved the first stage of the federal-backed Perth Freight Link, known as Roe 8, but protest group Save Beeliar Wetlands successfully challenged it in court.
The State Government then appealed, which the full bench of the WA Court of Appeal unanimously allowed on Friday.
Premier Colin Barnett said the State Government was still committed to proceeding with Roe 8 but the project had been delayed “at least six months”.
The State Government was pursuing a second environmental approval process in parallel with the appeal.
But Mr Barnett said repeating the environmental approval process would not be necessary with the successful appeal.
A contract for the project has been finalised but the State will need to revise it now the appeal has been successful.
“We need to revisit that, we won’t rush or panic, we’ll just go about it in an orderly way,” Mr Barnett said
Environment Minister Albert Jacob also welcomed the appeal decision, saying it had clarified state and local government departments’ assessment and approval processes.
“The importance of the Court of Appeal’s decision extends beyond just Roe 8,” Mr Jacob said.
“It’s an important one for all of government because it deals with the question of when a government policy becomes a mandatory relevant consideration for decision-making.
“An appeal was necessary to clarify the administrative requirements for assessment and
approval processes undertaken by State agencies and local governments.”
The minister will direct the reassessment process he ordered in May in the wake of the Supreme Court’s decision to invalidate the initial approval to stop.
“In light of today’s Court of Appeal’s decision, the reassessment of Roe 8 will no longer be
required because the original EPA assessment and my ministerial approval remains valid,” Mr Jacob said.
Meanwhile Greens MLC and spokeswoman for biodiversity and conservation Lynn MacLaren said the Court of Appeal decision only strengthened her party’s resolve to protect the Beeliar wetlands from the proposed Roe 8 freeway extension.
“This is a devastating road to nowhere through a peaceful, well-loved area of significant conservation value,” she said.
“This road never should have been approved.
“I support the community’s wish to take this all the way to the High Court if need be.
“If this decision stands clearly, WA’s current environmental laws are too weak to actually protect biodiversity and areas of high conservation value like the Beeliar Wetlands.
“The Greens will continue to work to strengthen environmental protection for the benefit of the community.”