'Dangerous dam-building race' threatening South Asia’s shared rivers: Researchers

As Bangladesh approves a vast new barrage, experts caution that unilateral river engineering is outpacing diplomacy, with potentially severe ecological and geopolitical consequences.

In a development that has raised alarm among water security experts, Bangladesh has given the green light to one of the largest river engineering projects in its history: the Padma Barrage. The massive structure, designed to restore water to the country’s drought-prone southwest, comes at a moment when upstream neighbours China and India are also accelerating their own dam-building programmes.

According to analysis published in The Conversation, the region is entering a dam-building race without the institutions needed to share its rivers peacefully. The article's authors, Professor Kenneth Bo Nielsen (University of Bergen) and Doctoral Researcher Anwesha Dutta (University of Bergen), warn that infrastructure is moving faster than diplomacy – a pattern that has already destabilised South Asia’s waterways.

“A Cycle of Unilateral Engineering”

The Padma Barrage, which will feature a dam more than two kilometres long, is intended to store monsoon water and release it during dry months. Its stated goals include reducing salinity intrusion, reviving smaller rivers in western Bangladesh, and supporting irrigation for rice and fish production.

But the project has drawn sharp scrutiny from Nielsen and Dutta. “Rather than easing regional water insecurity, the Padma Barrage risks adding to a cycle of unilateral river engineering across the subcontinent,” they write.

A key concern involves sediment. The Ganges carries exceptionally heavy loads, and dams cause rivers to lose speed, dumping sediment upstream. Nielsen and Dutta note that this problem has already displaced over a million people near India’s Farakka Barrage, built in the 1970s. “Constructing a second major barrier downstream … risks compounding these effects, potentially trapping additional sediment loads between the two structures and intensifying flooding pressure,” the researchers state.

Downstream effects could be equally serious. If the barrage diverts water into southwestern channels, reduced flows in the main river systems might not be strong enough to push back tidal seawater, “accelerating salinisation” in coastal areas rather than improving water security, according to the authors.

A Geopolitical Tinderbox

The timing of the project adds another layer of risk. China is building the world’s largest hydropower dam upstream on the Brahmaputra, and India has its own ambitious river-linking plans. Meanwhile, the 1996 Ganges Water Sharing Treaty between India and Bangladesh expires in December 2026.

“Rather than strengthening Bangladesh’s position ahead of treaty talks, the project could weaken its case for demanding more water from India by signalling that it can cope with reduced flows,” Nielsen and Dutta warn. Several rivers that the barrage aims to revive flow through both countries, meaning restoration will require genuine cooperation – not just concrete and steel.

A Diplomatic Opening?

The analysis does note one positive development: Bangladesh became the first South Asian country to accede to the UN Watercourses Convention in 2025. Nielsen and Dutta observe that this move gives Dhaka a stronger legal basis to push for equitable water-sharing, particularly as the Ganges treaty negotiations approach.

“The Padma Barrage is not an inherently misconceived project,” the researchers conclude. “Bangladesh’s water crisis is real, and the political pressure to respond is genuine.”

But they add a stark warning: “Without renewed water-sharing agreements and stronger cooperation with neighbouring countries, this new barrage risks repeating the pattern of unilateral river engineering that has already destabilised South Asia’s waterways. Infrastructure that outpaces diplomacy is a familiar reason for failure in the region.”

The challenge for Bangladesh, say Professor Nielsen and Ms Dutta, is to ensure the barrage becomes part of a strong legal and diplomatic framework – not another step in an escalating cycle of hydropolitical competition.