Snowy Hydro 2.0 has been given final approval.
The Commonwealth on Tuesday granted the mammoth renewable energy project the final environmental approvals it was waiting on.
The green light comes with conditions around the protection of heritage and native fish species and requirements to make data on mitigation strategies public.
Snowy Hydro will spend nearly $100 million on biodiversity and environmental initiatives, including a $73.8 million offset fund for the NSW National Parks and Wildlife Service to protect threatened species.
It comes just over a month after the NSW government signed off, which led to the chair of the state's fisheries scientific committee resigning in protest, saying the move would likely result in an endangered fish becoming extinct.
The project inside the Kosciuszko National Park involves the construction of a 240-metre long pumped-hydro power station about 800 metres underground, to generate 2000MW of power.
The government says it will create 2000 jobs during the construction phase and generate billions of dollars of investment in regional NSW.