The Greenbushes Lithium Mine is expected to expand following the Environmental Protection Authority's recommendation to approve the project.
The recommendation to environmentally approve the expansion is subject to certain conditions including the protection of threatened black cockatoos unique to the region.
The announcement follows a four-week public review process as part of the EPA's assessment of potential environmental impacts, and additional information provided by proponent Talison Lithium Australia Pty Ltd in response to issues raised in public comments and consultation with mining and environmental regulators.
EPA chair Dr Tom Hatton said the proposal was not expected to result in an unacceptable or unsustainable impact on the fauna listed as threatened under State and Commonwealth laws.
"Habitat types within the development envelope are reported to be well-represented in the immediate vicinity and broader Blackwood district," he said.
"Clearing of 350 hectares of native vegetation on mining tenements - in State Forest used for mining since 1888, timber and some agriculture - is unavoidable for the proposal to proceed.
"The proponent reduced the size of the development envelope and, in preference to further clearing within State Forest, located proposed infrastructure in areas already disturbed."
The EPA recommended detailed management plans to protect fauna and for the proponent to fund targeted land acquisitions and research to offset impact of lost habitat for threatened species.
A new road is proposed to divert increased traffic outside the Greenbushes town, along with recommendations to manage noise, vibration, dust and visual amenity. Water collection and controls will also be incorporated to help manage impacts in the Blackwood Valley catchment.
The report is now open for a public appeal period, closing on May 22, 2018. The Minister for Environment will make the final decision on the recommendation for approval. For more visit appealsconvenor.wa.gov.au.