Sahat Simatupang, Jakarta – The Indonesian Forum for the Environment (Walhi) in North Sumatra has accused seven companies of playing a significant role in the flash floods and landslides that have struck the North Sumatra's Tapanuli region.
According to Walhi, and supported by data from the North Sumatra Regional Disaster Management Agency (BPBD), the disaster has been unfolding since last weekend, Thursday, November 27, 2025, after a storm from the Malacca Strait made landfall on the border of Aceh and North Sumatra.
Walhi reports that 51 villages across 42 sub-districts in eight regencies and cities have been affected, with South Tapanuli and Central Tapanuli regencies hit the hardest. Both are part of the Tapanuli Harangan, or Batangtoru, Ecosystem – one of the last remaining tropical forest areas in North Sumatra.
As part of the Bukit Barisan mountains, the Batangtoru forest is a crucial water source, helping to prevent flooding and erosion and sustaining river basins downstream.
Walhi alleges that seven companies exploiting the forest have contributed to the current floods and landslides.
"This is undeniable evidence of ecosystem damage," said Rianda Purba, Executive Director of Walhi North Sumatra.
Rianda emphasized that the recent flash floods and landslides are not solely the result of extreme rainfall from Tropical Cyclone Senyar. Satellite images show that many of the affected areas have already been deforested.
"This is evidence of human intervention through policies that allowed forest clearance, leading to these disasters," he added.
Walhi is demanding that the government halt the operations of these companies in the Batangtoru Ecosystem to prevent similar disasters. The area is also a critical habitat for endangered species, including Tapanuli orangutans, Sumatran tigers, and tapirs.
Seven Companies Accused by Walhi of Contributing to North Sumatra Floods
1. PT Agincourt Resources – Martabe Gold Mine
Between 2015 and 2024, the company reportedly cleared around 300 hectares of forest in the Batangtoru River basin.
2. PT North Sumatera Hydro Energy (NSHE) – Batangtoru Hydropower Plant
The project hasallegedly removed over 350 hectares of forest along a 13-kilometer river stretch, altered river discharge, and caused high sedimentation due to tunnel excavation and dam construction.
Timber from the site is believed to have contributed to flooding seen in a viral video of the Batangtoru River at Trikora Bridge, South Tapanuli.
3. PT Toba Pulp Lestari Tbk (TPL) – Community Timber Plantation (PKR)
Thousands of hectares of forest in the Batangtoru River basin, mainly in Sipirok District, South Tapanuli, have reportedly been converted into eucalyptus plantations, contributing to deforestation and flash floods.
Forest degradation of 1,500 hectares has occurred in the wildlife corridor connecting Dolok Sibualbuali to Batangtoru West Block over the past three years.
4. PT Pahae Julu Micro-Hydro Power (PLTMH)
A small hydropower project in Pahae Julu, North Tapanuli, reportedly affecting forested areas and river flow in the region.
5. PT SOL Geothermal Indonesia – North Tapanuli Geothermal
Geothermal operations in North Tapanuli are said to have impacted forest cover and natural drainage in the area.
6. PT Sago Nauli Plantation – Oil Palm Plantation
An oil palm operation in Central Tapanuli Regency, contributing to forest loss in sensitive watershed areas.
7. PTPN III Batangtoru Estate – Oil Palm Plantation
Oil palm activities in South Tapanuli reportedly leading to deforestation and increased vulnerability to floods and landslides.
Tempo has reached out to PT Agincourt Resources for comment but has not received a response.
PT Toba Pulp Lestari, however, strongly rejected Walhi's accusations. Salomo Sitohang, Head of Corporate Communications, stated that all of TPL's activities comply with permits, regulations, and government provisions, and that operations follow documented standard procedures with consistent monitoring.