Hans Nicholas Jong, Jakarta – The Indonesian government has announced what it describes as a sweeping, science-based effort to reassess environmental governance, zoning and corporate accountability in the wake of floods and landslides that killed more than 1,100 people across the island of Sumatra.
The disasters were triggered by extreme rainfall linked to Tropical Cyclone Senyar, but government officials, scientists and environmental researchers say the scale of the destruction can't be attributed to the weather alone.
They point instead to long-term land-use changes – including deforestation and large-scale forest conversion – that have weakened natural buffers in Sumatra's upland watersheds, leaving landscapes unable to absorb intense rainfall.
The government has acknowledged that human-driven changes to land cover have fundamentally altered Sumatra's landscapes, reducing their capacity to prevent severe flooding and landslides when extreme weather hits.
"These changes are caused both by anthropogenic factors – such as the conversion of forest cover into non-forest areas – and by heavy rainfall, combined with the geomorphological characteristics of our soils, which are unable to adapt to these pressures," Environment Minister Hanif Faisol Nurofiq said.
The acknowledgment marks a significant shift in tone.
Rather than treating the disasters solely as natural events, the government is now explicitly linking loss of life and environmental damage to development decisions, land-use planning and corporate activity – and signaling that permits and licenses may no longer shield companies from accountability.
On Dec. 23, 2025, Hanif announced a three-pronged intervention covering Aceh, North Sumatra and West Sumatra, the provinces most severely affected by the disasters.
Three tracks of intervention
The first measure is a rapid assessment of disaster impacts to guide relocation, rehabilitation and settlement planning, expected to be completed by January 2026.
"This is important so that when permanent housing is later constructed, it is located far from disaster-prone areas," Hanif said.
The second is a review of provincial zoning plans, comparing approved zoning documents with environmental assessments and real conditions on the ground. The review will assess whether existing zoning plans comply with Indonesia's Strategic Environmental Assessment (KLHS) framework, and whether, even if compliant on paper, they failed to prevent catastrophic impacts.
"If spatial planning has already been completed but the resulting disasters are still extremely severe, then clearly something is wrong in the planning," Hanif said.
The third measure is a large-scale environmental audit of more than 100 business entities across sectors including mining, energy, plantations and housing. According to Hanif, the audits are intended to establish what occurred during the disasters – and what could have been prevented.
Audits have already begun in North Sumatra, where eight companies operating in and around the ecologically fragile Batang Toru ecosystem have been ordered to cease operations pending a government investigation.
Batang Toru is home to critically endangered species, including the Tapanuli orangutan, the world's rarest great ape.
The companies under scrutiny include pulpwood producer PT Toba Pulp Lestari, hydropower developer PT North Sumatra Hydro Energy (NSHE), and gold mine operator PT Agincourt Resources.
Hanif said the full audit process is expected to take up to a year, but investigations into major cases are targeted for completion by March, allowing authorities to pursue follow-up action, "whether through criminal proceedings, civil lawsuits, or administrative sanctions," he added.
The audits will apply to all companies without exception, Hanif said, and enforcement will not distinguish between licensed and unlicensed activities.
"Even if an activity is licensed, if it causes environmental destruction and loss of life, it will be acted upon," he said. "Compliance with permits does not exempt a company if its operations violate environmental safeguards and result in serious damage."
In carrying out the audits and zoning reviews, the Ministry of Environment is working with the Ministry of Higher Education, Science and Technology and scientists from universities across Indonesia.
"Everything must be based on exact sciences, with evidence that can be verified scientifically," Hanif said. "Science will ultimately state honestly what has happened and how it should be addressed."
Given the scale of the effort, the government will mobilize large numbers of academic experts, according to Brian Yuliarto, the higher education minister. He said discussions are underway to ensure legal protections for academics involved in studies that could have legal implications, citing existing safeguards under Indonesia's environmental laws.
"There is a strong legal basis to protect them," Brian said.
Cautious optimism from civil society
Some environmental groups have cautiously welcomed the government's initiative, saying it could open the door to long-overdue reforms if followed through.
Revisiting zoning plans – documents often treated as politically fixed – could enable policy revisions that restrict future extractive or infrastructure expansion, while also challenging projects that rely on permissive planning frameworks as justification, activists say.
Leonard Simanjuntak, Indonesia country director for Greenpeace, said the zoning plans in Aceh, North Sumatra and West Sumatra are deeply flawed because they zone forested areas for development rather than conservation, providing legal cover for large-scale forest conversion.
"These spatial plans then become the basis for permits and forest conversions," Leonard told Mongabay. "If we examine this closely, legally sanctioned environmental destruction [through zoning and permit issuance] may be far greater than illegal destruction as a root cause of these disasters."
He said Jakarta has the authority to revise provincial zoning plans – but whether it will do so remains uncertain.
"Will that happen? I have my doubts," Leonard said. "But we still have to be cautiously optimistic."