Why Rushing to Desilt Himalayan Rivers Is a Risk We Cannot Ignore

In a region like the Himalayas, sediment is not an inconvenience, rather a fundamental component of river stability.

In a region as fragile and dynamic as the Himalayas, sediment is not an inconvenience to be cleared away. It is a fundamental component of river stability that helps landscapes absorb shocks and protect downstream communities in a warming climate, writes Pratik Kad.

(Photo: The Quint)

Rising temperatures, increasingly erratic rainfall, and a growing frequency of extreme events are already reshaping Himalayan river systems. Against this backdrop, Union Minister of Power and Housing and Urban Affairs Manohar Lal Khattar's announcement that it plans to remove sediments at the Salal Power Project in Kashmir, in the name of “maximum utilisation of water resources,” deserves careful scrutiny.

The move is being framed as a technical necessity, particularly in the context of the Indus Waters Treaty being kept in abeyance.

But in a region as fragile and dynamic as the Himalayas, sediment is not an inconvenience to be cleared away. It is a fundamental component of river stability that helps landscapes absorb shocks and protect downstream communities in a warming climate.

Why Sediment Matters

Himalayan rivers are naturally heavy with sediment. This is not a failure of management; it is a consequence of where these rivers are born. They flow through one of the youngest and most seismically active mountain systems on Earth, where landslides, earthquakes, steep slopes, and intense rainfall constantly reshape the terrain.

Sediment, whether sand, gravel, or finer silt, is the material through which these rivers adjust their course, regulate their energy, and stabilise their banks.

When sediment is removed aggressively, especially over short-time scales, rivers behave differently. Water stripped of its natural sediment load flows faster and cuts deeper into the riverbed and banks. Hydrologists often describe this as “hungry water”, water that has excess energy and begins eroding everything in its path.

In a high-risk zone like Kashmir, where slopes are already unstable and infrastructure often sits close to river channels, this is not an abstract concern.

It directly increases the likelihood of bank collapse, slope failure, and downstream flooding, as seen in the floods and landslides the region experienced in 2025.

Climate change exacerbates this situation and makes it far more dangerous. The Himalayas are warming faster than the global average, and rainfall patterns are shifting in ways that amplify risk.

Extreme rainfall events are becoming shorter, sharper, and far more intense, overwhelming catchments that evolved under very different climatic conditions.

Cloudbursts now deliver large volumes of rain over small areas within hours, generating rapid runoff with little time for infiltration or gradual river adjustment.

In sediment-rich rivers, part of this energy is absorbed through channel roughness, temporary deposition, and floodplain storage. Once sediments are removed, rainfall converts far more directly into destructive flow. Water accelerates downstream with fewer natural brakes, increasing peak discharge, scouring riverbeds, undercutting banks, and triggering secondary landslides along already unstable slopes.

The recent Himalayan disasters show that it is no longer just how much rain falls that matters, but how quickly rainfall turns into runoff, and desilting shortens that pathway dangerously.

At the same time, glacial retreat across the Himalayas is accelerating, increasing the risk of glacial lake outburst floods (GLOFs). These sudden releases of stored meltwater send powerful flood waves downstream, often carrying large volumes of debris.

In such moments of extreme stress, sediment plays a crucial role. It acts as a natural buffer, slowing flow and dissipating energy across the riverbed. Sediment-rich rivers are better able to absorb shock. When this ballast is removed, floodwaves travel faster and strike downstream areas with far greater force. What might have been a damaging flood can quickly become catastrophic.

When Development Ignores the Limits of the Landscape

There is also a long-term problem that is often overlooked. Sediments trapped behind dams are not permanently “lost” to the river system.

Over time, rivers naturally redistribute this material downstream, rebuilding floodplains and reinforcing banks.

Large-scale desilting interrupts this process, simply shifting erosion elsewhere, often to locations where people live, farm, or depend on the river for their livelihoods.

The idea of “maximum utilisation” of water sounds efficient, but it reflects a narrow understanding of mountain rivers.

In the Himalayas, water cannot be separated from sediment, slope stability, and climate variability. Treating sediment as waste rather than structure applies a lowland engineering mindset to a high-mountain system where it does not fit.

This does not mean sediment management should never occur. But rushing into large-scale desilting without basin-wide studies, seismic risk assessments, and climate projections is deeply risky.

Kashmir sits at the intersection of multiple hazards: earthquakes, landslides, extreme rainfall, and rapidly changing cryospheric conditions. Intervening in such a system without respecting its internal balance can trigger consequences far beyond the project site.

As climate extremes intensify, resilience will not come from forcing Himalayan rivers to behave more efficiently. It will come from allowing them to retain the features that help them cope with extremes.

Sediment is one of those features. Removing it in the present climate is not a neutral technical choice. It is a gamble with downstream safety in an already unstable region.

In the Himalayas, development decisions must be guided not just by how much water can be extracted, but by how much risk the landscape can absorb. Ignoring that distinction is how climate disasters stop being “natural” and start becoming avoidable.

(Dr Pratik Kad is a Climate Scientist, currently working as a PostDoc at NORCE Research in Bergen, Norway. He is an affiliated member of the Bjerknes Centre for Climate Research.This is an opinion piece and views expressed are the author's own. The Quint does not endorse nor is responsible for them.)