Many observers linked the Sumatra flash floods in late 2025 to extreme rainfall associated with climate change. Heavy rain caused rivers to overflow and landslides to occur, destroying communities in Aceh, North Sumatra, and West Sumatra and costing many people their lives and livelihoods. Climate conditions were clearly important, but focusing only on weather misses a deeper structural issue. To explain how severe these floods have become, it is necessary to look at the long-standing institutional arrangements governing Indonesia’s forestry sector.
Forests are crucial to hydrological systems, as intact ecosystems capture rainfall, enhance infiltration, stabilize soils, and regulate river flows. Empirical studies across tropical regions consistently show that deforestation increases surface run-off, sedimentation, and the probability of flash flooding, particularly in steep upstream catchments.
In Indonesia, particularly in Sumatra, studies show that upstream watersheds have undergone decades of forest degradation. Logging – both legal and illegal – combined with plantation expansion, mining, and infrastructure development, has fragmented forest cover and compacted soils.
Intense rainfall causes runoff to move rapidly downslope, transporting soil and debris into rivers that lack the capacity to absorb sudden surges. The large amounts of timber debris seen during recent floods are not coincidental. They point to changes in land use upstream rather than unusual natural events.
Historical institutionalism is a way of understanding why certain problems persist over time. It looks at how today’s political systems and decisions are shaped by past choices, traditions, and power structures. In particular, it examines how the interests of powerful groups, shared ideas about how things should work, and the original design of government institutions influence what happens later. The approach highlights how policy choices made early on can lock countries into particular institutional paths, which reinforce themselves over time, making those systems difficult to reform.
Indonesia has long treated its forests as economic resources under state control. During the Dutch colonial period, forest regulation served the extraction of resources and the exercise of territorial control. After independence in 1945, this logic was consolidated rather than dismantled. The Basic Forestry Law of 1967 placed vast forest areas under central state authority and enabled the expansion of large-scale timber concessions as part of a national development strategy.
As it evolved, the system came to be defined by centralized authority, concession-based management, and the routine neglect of local land rights. Forestry agencies developed administrative routines oriented towards licensing and revenue generation rather than ecosystem protection. Once entrenched, these arrangements proved difficult to reverse, even as their environmental consequences became increasingly apparent.
The political changes that followed Indonesia’s transition to democracy in the late 1990s reshaped parts of forest governance, but left its overall direction largely intact. Decentralization transferred certain administrative powers to district governments, yet it also generated new incentives for forest exploitation, as local authorities sought revenue through permit issuance.
In practice, decentralization changed who participated more than how the system functioned. Extractive arrangements remained largely intact, even as additional actors entered the field. Central ministries retained significant authority, while local governments operated within overlapping and sometimes contradictory regulatory frameworks. This institutional complexity often weakened enforcement and accountability, particularly in remote upstream areas critical for watershed protection.
From a historical institutionalist perspective, this represents institutional layering rather than displacement: new rules were added without removing old ones, allowing extractive practices to persist under altered administrative arrangements.
This situation then strengthened the case for recentralization. The status quo prompted a set of laws and regulations related to the forestry sector to support this shift, including the Regional Autonomy Law of 2014, which further narrowed regional authority in this sector.
Over the past 20 years, Indonesia has launched a series of efforts to strengthen forest governance. These include social forestry programs, moratoriums on primary forest clearing, certification schemes, and participation in international climate initiatives such as Reducing Emissions from Deforestation and Forest Degradation (REDD+). Although these measures have produced important gains, their impact on flood risk has been uneven.
One of the main challenges is the clash between competing policy priorities. Conservation programs run in parallel with development policies that continue to encourage plantation growth, mining, and infrastructure projects in or around fragile watershed areas. Spatial planning often prioritizes economic growth, treating environmental considerations as secondary constraints rather than core determinants of land use.
The ability to enforce rules remains uneven across regions. Forest governance has long been shaped by political influence and regulatory capture, while local communities – despite suffering the most significant environmental impacts – often lack the authority to safeguard surrounding forests. As a result, institutional incentives continue to favor short-term extraction over long-term risk reduction.
Climate change does not operate in a vacuum. In Sumatra, rising rainfall intensity interacts with degraded landscapes to produce disproportionately severe outcomes. Forests that once moderated hydrological extremes have been removed, and river systems altered by sedimentation and land-use change now respond more violently to precipitation shocks.
In this sense, climate change functions as a threat multiplier rather than a primary cause. It exposes vulnerabilities created by decades of governance decisions and magnifies their consequences. Without institutional change, adaptation measures risk becoming increasingly reactive, costly, and insufficient to prevent future disasters.
Reducing flood risk in Sumatra requires more than technical fixes or post-disaster responses. It calls for a shift in forestry governance towards prevention and ecological resilience, moving beyond concession-based land allocation to integrated landscape management.
Forestry policy must align with spatial planning, water governance, and disaster management. Forests – especially in upstream watersheds – should be treated as public safety infrastructure, not as a separate environmental issue. Strengthening community forest management and local land rights can improve protection.
Above all, accountability must move upstream, with land-use decisions assessed for flood risk before permits are issued.
The flash floods in Sumatra are more than climate-driven disasters. They expose long-standing institutional choices in Indonesia’s forestry governance that have favored extraction over ecological resilience. How Indonesia reorients its forestry institutions will shape the way future climate extremes are experienced.
Originally published under Creative Commons by 360info™.
