Researchers develop ‘sedimentation budget’ to guide India’s river revival efforts
Scientists unveil a first-of-its-kind “sedimentation budget” to map sediment movement in Indian rivers.
Tool could guide restoration efforts as the River Ganga faces its worst drought since the 16th century.
Climate shocks and unplanned development are accelerating erosion, bank collapses and shifting river courses.
Sediment imbalance is damaging farmland, increasing flood risks and altering river morphology.
Researchers say the model can be replicated nationwide to design targeted rejuvenation strategies.
India’s efforts to revive its ailing rivers may receive a crucial boost from a new scientific tool designed to track how sediment moves through waterways. Researchers from IIT Gandhinagar and the Prayoga Institute of Education Research have developed a “sedimentation bank” — an accounting-style system that maps where riverbed sediments originate and where they accumulate, providing planners with a clearer picture of how to manage and restore fragile river systems.
The tool arrives in a year marked by severe climate shocks across India. In 2025, catastrophic landslides in Uttarakhand and flash floods in Himachal Pradesh dominated headlines, even as slower, more insidious crises unfolded elsewhere. The Ganga — the river that sustains 600 million people and underpins an estimated 40 per cent of India’s gross domestic product — is drying at a rate scientists say has no precedent since the 16th century. Rapidly receding Himalayan glaciers have accelerated the decline.
Against this backdrop, governments have leaned on a familiar mix of mitigation measures: pollution control, urban planning reforms, afforestation and restrictions on water diversion and groundwater extraction. But researchers argue that one of the most fundamental forces shaping the river’s future is sedimentation, which has long been overlooked.
Sedimentation determines how river flow patterns change under climate stress. Altered rainfall — whether excessive or scant — can cause sediments to erode and travel unpredictably, inundating banks or stripping them bare. The consequences ripple outward, waterlogging in some places, saltwater intrusion in others, and declining soil productivity across agricultural regions.
When sediment is lost, banks weaken and collapse. Human interventions worsen the strain. Vegetation clearing, river rerouting, encroachment on riparian land and unregulated construction all magnify erosion. A stark example came from Murshidabad district, where part of the Ganga-Bhagirathi bank gave way, displacing communities and destroying farmland.
Embankments, sand mining and dredging, often promoted as flood-control or navigation solutions, can similarly disrupt the river’s natural equilibrium, increasing downstream flood risks by altering water speed.
Sediment imbalance also affects fertility. Finer sediments tend to travel further, settling downstream and depriving upstream farmlands of nutrients. Coarser materials accumulate behind dams. Over time, these shifts can force a river to change course, fragment into multiple channels or, in extreme cases, dry out entirely.
This is where the new sedimentation bank could make a difference. By tracing sediment sources and destinations, the tool creates a budget-like ledger of movement and accumulation. Researchers say this can help policymakers anticipate hazards, design restoration plans and monitor whether interventions are working.
“The sedimentation budget charts out where the sediment is coming from and where it is going. It is an account of sorts that helps us understand the direction and quantum of sediment movement and its implications for river ecosystem management,” Ajit Singh, co-author of the study, said in a statement. “The study offers a template that can be replicated for other river systems to aid targeted rejuvenation efforts.”
Manaswini Vijayakumar is Research communications professional at Prayoga Institute of Education Research. Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth