Indonesian Government Probes Mining Links in Deadly Sumatra Floods Amid Denials from Martabe Gold Mine

Government Launches Extensive Investigation into Sumatra Floods

The Indonesian government has initiated a comprehensive investigation into allegations that mining activities may have exacerbated the devastating floods and landslides that recently struck South Tapanuli, North Sumatra, and other parts of Sumatra. The probe comes as the operator of the Martabe gold mine, PT Agincourt Resources (PTAR), vehemently denies any links between its operations and the disaster.

Energy and Mineral Resources (ESDM) Minister Bahlil Lahadalia confirmed that authorities are reviewing the potential impacts of mining concessions across affected regions, including areas where the Martabe mine operates. He stated that strict sanctions would be imposed on any companies found violating environmental or operational regulations. Minister Lahadalia personally visited the Martabe site, noting that the river near the mine was the smallest of three major waterways in the area and not the primary source of the flooding. Operations at the Martabe gold mine have been temporarily halted, with the company instructed to support emergency response efforts.

Separately, Forestry Minister Raja Juli Antoni identified several companies potentially linked to large quantities of logs swept away by the floods, examining whether the timber originated from illegal logging, land clearing for plantations, or mining. He indicated that 12 companies are suspected of contributing to recent hydrometeorological disasters and that the ministry plans to revoke approximately 20 forest-use permits. Environment Minister Hanif Faisol Nurofiq identified plantation forestry operations, major hydropower development projects, and intensive gold mining as key factors contributing to the worsening floods in the Batang Toru Watershed.

Martabe Gold Mine Rejects Allegations, Cites Extreme Weather

PT Agincourt Resources (PTAR), the operator of the Martabe gold mine, has issued a detailed rebuttal to the allegations, describing them as 'premature and inaccurate.' The company attributes the disaster primarily to Tropical Cyclone Senyar, which brought extreme rainfall, reportedly unmatched in at least 50 years, across northern Sumatra.

PTAR emphasizes that its operations are located in the Aek Pahu watershed, which is hydrologically separate from the Garoga watershed, where the flash floods occurred. The company stated that its monitoring found no wood material in the Aek Pahu watershed that could be associated with debris found in the flooded areas. Aerial observations conducted by PTAR revealed multiple landslides along the Garoga river, including within protected forest zones, which the company suggests contributed substantial debris into the river system.

Since the onset of the disaster, PTAR has been actively involved in emergency response efforts, deploying heavy equipment, establishing emergency shelters, field kitchens, and community clinics, and assisting joint search and rescue (SAR) operations with local authorities. The company maintains that it complies with all environmental regulations and operates entirely within non-forest zones.

Environmental Groups Highlight Degradation Amidst Rising Casualties

Environmental organizations, such as the Indonesian Forum for the Environment (Walhi), have intensified scrutiny of extractive industries, warning that years of weak oversight and large-scale deforestation have magnified the scale of the ecological disaster. Walhi North Sumatra accused seven companies, including PT Agincourt Resources, of playing a significant role in the floods and landslides.

According to Walhi, approximately 1.4 million hectares of forest cover were cleared across Aceh, North Sumatra, and West Sumatra between 2016 and 2025 to make way for businesses like plantations and mining. The group highlighted that the Batang Toru watershed, which includes the flood-stricken regencies of South, Central, and North Tapanuli, lost nearly 73,000 hectares of forest between 2016 and 2024. Walhi has called for the government to halt the operations of these companies in the Batangtoru Ecosystem to prevent similar future disasters.

The floods and landslides, which began around November 25, 2025, have resulted in a significant humanitarian crisis. As of December 4, 2025, the National Disaster Mitigation Agency (BNPB) reported a death toll of 836 and 518 people missing across Aceh, North Sumatra, and West Sumatra. Earlier reports indicated 20 fatalities, 58 injured, and 6 missing in North Sumatra by November 26, 2025, with South Tapanuli District alone recording 8 fatalities, 58 injured residents, and the displacement of 2,851 people. The disaster has affected seven districts/municipalities in North Sumatra, with South Tapanuli and Central Tapanuli being among the hardest hit. Over 1.2 million people have been displaced, and 10,400 homes and hundreds of public facilities have been damaged or destroyed across the affected provinces.

Ongoing Assessments and Calls for Accountability

The Indonesian government continues its assessments in North Sumatra and Aceh to determine the full extent of mining's contribution to the disaster. Ministers have pledged to take strict action against any companies found in violation of environmental standards. The ongoing investigations underscore growing public pressure for greater accountability in the forestry and mining sectors amidst concerns over environmental mismanagement.