The Federal Environment Minister Sussan Ley has approved the Narrabri gas project, subject to a number of conditions she said would "safeguard the biodiversity of the Pilliga forest".
The $3.6 billion project would drill up to 850 wells in the area.
Minister Ley's conditional approval includes an early warning system to "identify any potential impacts on groundwater aquifers before they occur"; cease-work provisions; and a chemical risk assessment.
Santos, the energy company behind the project, will also establish a $120 million Community Benefit Fund.
Gomeroi woman Linda Whitten told NITV News she was upset that the project had gained environmental approval from the government.
"It wasn't a surprise," she said.
"But it still doesn't make you feel good. In this day and age, why is there so much hatred, I guess, that's how it feels to me - a hatred for my people and our culture.
"Not just Gomeroi mob, but all the mobs across this Country. They're systematically eradicating every trace of us."
Ms Whitten said there have been fights against multiple mining companies on her Country, including Whitehaven and Shenhua for 15 years, and Gomeroi people need to see a win.
“I’m devastated, I’m devastated for my people," she said.
"Because now we have to continue, we have to continue the fight and when does it end.
"It really does feel like that."
'Number one fight'
Traditional Owner Polly Cutmore said Gomeroi people would continue to mobilise and fight against the project.
"These policies and procedures are just to suit white men, not us,” she said.
“This is just another example of attempted, devastating colonialism, only now instead of hiding behind the fence, we’re at the table. We are coordinating.
"Gomeroi people are coming together, the whole Gomeroi Nation are talking about the destruction of the gas mining, especially to the Great Artesian Basin.
“That’s the number one fight we have - to save the Great Artesian Basin.”
Following the federal Coalition's approval, the NSW government announced a potential Narrabri 'Special Activation Precinct', which would "leverage opportunities brought about by the Narrabri Gas Project".
NSW Deputy Premier John Barilaro said the Narrabri gas project will open up opportunities for growth in industry ranging from plastics to fertiliser and construction material.
“This is great news for the local economy, and it is why the government will now start investigating a potential Special Activation Precinct in Narrabri," he said.
“We want to create a thriving energy hub in Narrabri focused on value-added production and manufacturing to power long-term job opportunities across the region."