Turnbull has given the green light for the $20 billion gas project, subject to dredging conditions.

“Strict environmental protection measures will be required to protect Commonwealth environment matters, including listed threatened and migratory species and rare vegetation on Barrow Island,” Turnbull said yesterday.

These measures include:

* development and implementation of a quarantine management plan, overseen by an expert advisory panel, to protect threatened species on Barrow Island;

* development and implementation of a protection regime for the Flatback Turtle;

* environmental management plans for the operation of the gas field and refining plant;

* annual environmental performance reports to the Department of the Environment and Water Resources.

This builds on Chevron’s existing commitment to put in place a suite of environmental protection measures including a $60 million commitment by the Gorgon joint venturers to conserve the Flatback Turtle and other endangered species.

The development will involve recovering gas from the Gorgon field near the North West Shelf gas fields off the WA coast and constructing a gas refining and liquid natural gas facility on Barrow Island.

Chevron Australia General Manager for the Greater Gorgon Area, Colin Beckett, said the Minister’s decision was a welcome outcome after four years of rigorous state and federal assessment which has produced a comprehensive environmental management regime.

“The Western Australian and Federal governments have provided an environmental management regime under which the project proponents, governments and community can continue working together to maintain the conservation values of Barrow Island while generating significant economic benefits into the future,” Beckett said.

“We will now build the detailed environmental conditions into our work. We are doing as much work as possible to ensure Australia’s largest known gas resource is developed in an effective, efficient, responsible and internationally competitive manner.”

Barrow Island contains Australia's largest onshore oil field but is also an A class nature reserve and environmentalists have argued it should be protected from further development.

It is widely agree that over the last 40 years Chevron has done an excellent job of protecting the local environment at Barrow, but there are concerns that the a project the scale of Gorgon would inevitably be harmful for the island's ecosystem.

The State Government recently gave its approval for the project subject to 36 conditions.

The Gorgon partners are Chevron Australia (operator and 50%), Shell (25%) and ExxonMobil (25%).

The approval decision and conditions are available at: www.environment.gov.au/epbc