Learning from Nepal’s floods: Why Bangladesh’s hydro-diplomacy must be built on risk sharing

On the morning of 26 August, with no rain falling, a surge of water, ice and rock came down the mountains on Nepal's border with China and tore through the valley below. High on the frontier, the lower section of a glacier had given way, dropping debris more than a kilometre onto the valley floor and sending a flood down the stream. 

As of the afternoon of 29 August, Nepal's authorities had confirmed 734 deaths and 2498 missing. Officials described it as the worst disaster of its kind in memory. 

Bangladesh does not sit beneath a Himalayan glacier, but it does sit at the receiving end of a vast transboundary river system in which water, weather information and infrastructure decisions travel downstream, often much faster than diplomacy. 

And that's what happened when eastern Bangladesh flooded in August 2024 affecting around 5.8 million people across 11 districts. More than half a million people were displaced into thousands of shelters, according to the World Health Organization. 

For downstream Bangladesh, Nepal's catastrophe warns us that preventing the next disaster, be it natural or man-made, will require river-level readings, real-time dam data, basin-wide cooperation, and hydro-diplomacy. A glacial surge in Rasuwa and an unannounced release on the Gomti are different hazards, but both leave the downstream country reacting to a wall of water it did not see coming, and the government has to figure out the strategy to prevent such catastrophe.

What the 2024 floods revealed

When the 2024 Southern Bangladesh flash flood began on the night of 21 August, allegations quickly emerged that India had suddenly opened the Dumbur dam on the Gomti River without adequate warning.

India denied that the dam had caused the flood, saying exceptionally heavy rainfall across the catchment and water entering downstream of the dam was primarily responsible. India said it had transmitted rising water-level data until 3 pm on 21 August, but a flood-induced power outage disrupted communication three hours later. 

That distinction determines whether authorities have hours to evacuate a community or merely minutes to watch it disappear. And it was a crucial information failure on the neighbour's side. When the water reached homes, Bangladesh still lacked the data required to determine independently and immediately what upstream structures were doing. 

Mostofa Kamal Palash, a meteorologist, climate researcher and founder of the weather platform abohawa.com, points out that Bangladesh's forecasting was built for a different kind of flood. 

The Flood Forecasting and Warning Centre (FFWC) issues five and ten-day flood outlooks from a forecast model and puts out two daily bulletins giving the water level and the rising or falling trend at each station, but it is suited to the big rivers that swell over days, not to the eastern rivers that can rise in hours.

"Moreover, the water release from Tripura was not communicated to Dhaka in time. Each broken link was a chance to move people that were lost," he added. 

And it should be noted that water-level data is not dam data. 

"After what has happened in Nepal, bilateral cooperation alone will not be enough. We need a multilateral mechanism involving Nepal, Bhutan and China. We need information not only about water levels, but also about glaciers, hydropower stations, dams and barrages across the region." Sheikh Rokon, writer and river researcher

Sheikh Rokon, writer, river researcher, and founder and secretary general of Riverine People, said Bangladesh and India already exchange rainfall and river-level information through established mechanisms. Data is transmitted twice daily and communicated through email and an instant-messaging channel.

"India does not share information with Bangladesh about when those dams are releasing water and when they are closing them. What they share with Bangladesh is only the water level. But what we need is information about dam operations, specifically, when they are releasing water. We may know where some of them are, perhaps through Google, but officially, they do not provide that information. So the fundamental issue is that they do not share information relating to the operation and infrastructure of dams and barrages." 

India itself recognises the danger. Its Central Electricity Authority maintains a standard operating procedure for early-warning systems at hydropower projects. 

From sharing water to sharing risk

Mohammad Azaz, founder of the River and Delta Research Centre, argued that Bangladesh's hydro-diplomacy has traditionally been trapped inside a single question of how much water Bangladesh is entitled to receive. That remains important, particularly during the dry season. But the new politics of water is also about timing, infrastructure, energy and risk.

"What we need to do now is rethink our approach to the transboundary waters upstream of us, including the projects India has there," he said. 

He added, "For example, if an upstream country says that it needs electricity or irrigation, those are legitimate concerns. The question is what kind of assistance programme we can offer in response." 

Azaz proposed treating upstream hydropower as part of a wider regional bargain. The obvious objection is that India has little reason to trade away infrastructure it controls for a downstream neighbour's peace of mind, and that its preference for bilateral talks is itself a form of leverage that transparency would dilute. That is precisely why any such bargain has to offer India something it wants as well, be it power, grid access, a cheaper route to its own energy targets — rather than appeal to basin solidarity. 

Polash said, "I believe that all rivers that cross the Bangladesh-India border must be monitored on a sub-hourly basis by an automated rain Gauge every 15 minutes and updated through a GIS-based dashboard. The most sensitive international river crossing should be monitored with CC cameras, if possible. Specifically, Netrokona, Synamgonj, Sylhet, Feni and Cumilla districts." 

A river system too big for bilateralism

Bangladesh and India share a Joint Rivers Commission, while flood information is exchanged through bilateral arrangements. But the Ganges-Brahmaputra-Meghna system does not begin at the India-Bangladesh border.

Its headwaters, glaciers, tributaries and hydropower infrastructure stretch across China, Nepal, Bhutan and India. This has historically been difficult because India prefers bilateral river negotiations. Yet Bangladesh now possesses an opening that it did not have in 2024.

In June 2025, it became the first South Asian country to join the UN Water Convention. The convention provides a framework for joint monitoring, information exchange, warning systems, consultations and cooperation over transboundary waters. 

India, Nepal, Bhutan and China are not parties. The convention cannot compel them to share data. But Bangladesh can use its membership to place basin-wide operational transparency on the diplomatic agenda, request technical assistance and develop model protocols that neighbouring countries may join without first negotiating a grand regional water treaty.

China complicates every version of this. It sits above the entire system, shares little of its hydrological data as a matter of policy, and has used that data as leverage before. It stopped passing Brahmaputra flood readings to India during the 2017 Doklam standoff. In July 2025 it began construction of a roughly 60-gigawatt cascade of dams on the Yarlung Tsangpo, the river that becomes the Brahmaputra. And that is the gap that Sheikh Rokon kept coming back to. 

After what has happened in Nepal, he believes bilateral cooperation alone will not be enough. 

"We need a multilateral mechanism involving Nepal, Bhutan and China. Bangladesh is downstream, India is in between, and Nepal and China are upstream. We need information not only about water levels, but also about glaciers, hydropower stations, dams and barrages across the region," he said. 

The existing South Asia Hydromet Forum already brings together hydrological and meteorological agencies from Bangladesh, Bhutan, India, Nepal and other regional countries. Its forecasters meet weekly, while its knowledge platform supports regional information exchange. 

But the forum trades in rainfall and river forecasts, not in the operational data. 

Bangladesh's approach to transboundary water management will therefore need to move beyond monitoring river levels to understanding and anticipating changes in upstream water flows. That means securing timely information on the operation of dams, barrages and hydropower projects, while building channels for cooperation with the wider network of countries sharing the region's river systems. 

Mohammad Azaz said, "Hydropower diplomacy needs to go beyond simply exchanging hydrological data. Since the river is shared, we need to take a holistic approach that considers both sides' rights and interests." 

Polash added, "I would advise setting up an emergency siren along the border, extending 30 km inland. Most importantly, people living in the immediate vicinity of the border region at the international river crossing must receive cell phone-based emergency alerts in the event of life-threatening hazards such as flash floods, landslides, dam breaks, etc."