Rio Tinto has suspended all operations at Pannawonica and Brockman/Nammuldi, and pit operations at Tom Price and Paraburdoo, as a severe low-pressure system and associated trough results in prolonged heavy rain across the west Pilbara region.
According to a company statement, many roads are impassable and all employees have been advised to exercise extreme caution.
Ten people stranded at Yarraloola station, west of Pannawonica, were evacuated safely by helicopter to Karratha as water rose.
Operations at Marandoo and the east Pilbara mines (Yandicoogina, West Angelas and Hope Downs) have not been significantly impacted at this stage.
Most rail movements have been suspended due to flooding, and a comprehensive assessment is being carried out to ensure that operations will be able to resume safely.
Track inspections and recovery plans are underway.
Coastal operations at Dampier and Cape Lambert have also been significantly impacted.