Brandy Hill quarry has made Port Stephens an unlikely lightning rod for koalas and environmental activism.

It is a quarry that has been in place for decades and will expand in stages over the next 25 years, mining a rhyodacite aggregate hard rock, vital for building infrastructure.

The project came to me after the NSW government approved it, with strict environmental conditions requiring an area almost nine times the size of the expansion zone to be set aside as offsets.

I visited the site, met with quarry workers and with campaigners against the project. I went with an open mind.

Following that visit and hearing so many competing views, I commissioned an independent survey, conducted by leading koala expert Dr Stephen Phillips from Biolink. That survey showed that within that habitat area to be cleared, between one and two koalas are present.

Port Stephens is not a region where bushfires have impacted local populations or habitat and the Biolink report states that "movements across the site are largely random and comprised mostly of young dispersing males".

However, as part of my approval for its expansion, I have ensured that the company will commit to regenerating a 74-hectare corridor of high-quality koala habitat on the land it owns.

Of vital importance is the fact that the new corridor will be better quality habitat for koalas than the quarry expansion footprint. My department and I will approve the vegetation and koala management plans.

For those who see Brandy Hill Quarry as a symbol of wider campaigns, these outcomes may count for little but they are important, just as it is important to ensure that decisions are based on rigorous assessment, and that they are based on science rather than emotion.

The areas of land owned by the proponent, near where koalas have been sighted by residents, will now be the subject of a multi-million dollar regeneration effort that will establish a much-needed east-west habitat corridor across the southern end of land owned by Hansons, which has previously been used for grazing.

It will include bushfire buffer zones that will also help protect koalas from car and dog strikes, the latter of which are among the more significant threats to koalas on the edge of this rural residential area.

The Morrison government is at the same time investing $200 million in bushfire wildlife and habitat recovery which continues to benefit koalas and other species.

We have invested in koala hospitals and major zoos who's veterinary centres have played a lead role in caring for koalas through bushfires and in the face of other threats.

We are being guided by experts in the field identifying where the greatest challenges are, and these remain our focus.

The 'fight' for Brandy Hill is evidence of the passion people both here and overseas have for this iconic umbrella species.

It is right that there is a close lens applied to projects that could have negative impacts on a species that is already protected under environmental and which I have ensured is being re assessed by the Threatened Species Scientific Committee.

The decision to allow the project is one that is based on an evidence-based approach.

As a result of what has been an exhaustive and stressful process for many, koalas in the area will now have access to a new corridor, improved vegetation and the best possible protection efforts.