McArthur River Mine is reopening after Cyclone Megan

One of the NT’s largest mines is reopening in the wake of Cyclone Megan. Read what happened on site.

Mining operations at McArthur River Mine are gradually being restored as crews work to repair the damaged facility after it was damaged by Cyclone Megan.

Owner Glencore said crews in the mines “upper areas” were being safely brought back online “in a phased manner”.

A statement from Glencore said water remained at the bottom of the open pit from the rain that fell during the tropical low that struck the Gulf of Carpentaria last month, as well as from groundwater inflows and operational water.

MRM ceased operations on March 18 and personnel were returned to the accommodation village before a resumption of activity the following day.

Glencore said 274mm of rain fell in a 24-hour period, eclipsing the previous rainfall record of 197mm in 1974.

Borroloola was hit with record breaking flooding following Cyclone Megan on March 18, 2024. Picture: Roper River Council

Company spokesman Francis Da Rosa told the NT News the company was returning to full operation on-site.

“Following these events, MRM personnel mobilised to carry out initial assessments on all of our key operational domains and water infrastructure onsite,” the MRM statement said. “We are continuing to do these assessments on a daily basis.”

Glencore said the flood levy wall was designed to withstand a one-in-500 year event – and it did that successfully. Despite the hectic rainfall, the tailings dam also stood solid.

“At no point was the tailings storage facility at risk of releasing water into the environment,” Glencore’s statement said.

“The TSF has been extremely well managed, a testament to our processes and skilled operators. The TSF has performed as designed and its structural integrity has not been compromised.”

Testing confirmed water quality in McArthur River was “good” and MRM is discharging water offsite in accordance to its waste discharge license.

Glencore also confirmed that workers trapped by the cyclone and flood waters were forced to sleep in administrative buildings.

“As a result of rising floodwaters on Wednesday March 20, the internal road between the MRM village and operational areas was cut off,” Glencore said.

“This meant 208 workers, including the MRM management team, spent the night in administration buildings.”

Glencore said it was prepared to assist with the evacuation of Borroloola residents if required and maintained support for residents trapped in the town or evacuated to Darwin.

It provided helicopter support for multiple evacuations of families and medical emergencies as well as support to Telstra for the restart of regional tower communications. The company also undertook aerial road services to the government.

MRM and South32’s Gemco mine were both seriously interrupted by Cyclone Megan, with mining still suspended at the Groote Eylandt facility after a bulk carrier slammed into the jetty.

South 32 is expected to provide a site update on Thursday.