Environmental advocates have taken Federal Environment Minister Tanya Plibersek to court over the approval of a new Bunbury Highway that will clear 60ha of habitat critical to endangered animals.

The Friends of The Gelorup Corridor faced Perth’s Federal Court of Australia again this week to argue that Mains Roads have not shown how it will offset the environmental damage caused by constructing the 27km Bunbury Outer Ring Road (BORR).

BORR will link Forrest to Bussell Highway and is touted to improve road safety, reduce traffic and create jobs. But will also see the clearing of 60ha of tuart and banksia woodlands – habitat for critically endangered native species, such as the western ringtail possum and black cockatoo.

On Thursday, opponents said the project breaches environmental laws and Main Roads should not have been granted construction approvals before adequately showing how it would offset – or compensate – for the loss of habitt.

Ms Plibersek’s lawyer Emrys Nekvapil argued offsets are not necessary for approvals.

Mr Nekvapil said the Minister approved the road under the justification she was confident an appropriate offset plan would be found during construction.

Friends of the Gelorup Corridor lawyer Angel Aleksov said the approval of the BORR, without an appropriate offset plan, sets a dangerous precedent.

The decision to approve has been made before the conditions of the offsets are understood and Mr ALeksov says this goes against using the precautionary principle – a legal obligation in planning approvals that affect endangered species.

Mr Nekvapil said the minister had a “high degree” of confidence Main Road’s future offset plan will provide 100 per cent offset.

Carnaby’s black cockatoos are endangered and experts say habitat loss is threatening the species’ existence. Photo credit: Craig Duncan

“The nature of the condition was, ‘I (the minister) am satisfied, I am going to allow it to go ahead, and it is going to be offset later.”

But Mr Aleksov said the lack of an offset plan directly contradicts the precautionary principle.

“In our case, the precautionary principle has not been met in regard to offsets,” Mr Aleksov said.

“Once the principle is being considered, the delegate’s (Environment Minister) view might change,” Mr Aleksov said.

But Mr Nekvapil argues the precautionary principle was applied.

A spokesperson for Main Roads said the BORR has an “extensive offset package” that will rehabilitate degraded areas and protect already vegetated areas.

The spokesperson said they are committed to protecting and supporting the western ringtail possum, and other fauna impacted by the construction of the road.

Construction on the $2.1b project, which has almost doubled in cost from projections, begin in February 2021.

Mr Aleksov saidt least one possum had already died as a result of works on the road.

Greens Senator Sarah Hanson-Young labels the project a disaster for the environment.

“The Environment Minister had the opportunity to halt this project when she considered its environmental credentials in June last year, yet she chose to give the green light to the destruction of critical habitat without any guarantee of protection,” Ms Hanson-Young said.

“As argued in this Federal Court appeal, an offset plan should have been in place well before this project was given the green light.

“Yet clearing continues and this plan is still not in place.”

Member of the Friends of the Gelorup Corridor, Joanne Munro, said she knows the final decision will not save the Gelorup Corridor, but it will have wider implications in the future.

“It sets a precedent, that offsets, one of the cornerstones of environmental legislation, could be essentially rendered irrelevant,” Ms Munro said.

Federal judges Geoffrey Ross, Michael Feutrill and Darren Jackson are yet to reach a verdict.