Recurrent floods: Looking through climate change and transboundary water governance lenses

The recent floods have left many people isolated and in urgent need of food, clean water, medicine, and dry clothes. Photo: Md Minhaj Uddin

There has been a lot of fuss and debate on science and politics as much of eastern Bangladesh was devastated by flash floods just weeks ago, extending from Sylhet in the north through Comilla, Feni, and Noakhali to Khagrachari in the south. 

While different groups have their own narratives, it can be stated with facts that a combination of global, regional, and national drivers has all combined to create the current record-breaking flood in the history of Bangladesh.

The global narrative outlined by weather and climate change experts concludes with three natural factors that caused the ongoing flooding. First, the impacts of the existing El Niño and a persistent monsoon low-pressure system over Bangladesh have caused continuous rainfall. 

Second, a strong Madden-Julian Oscillation, a significant component of tropical atmospheric variability, is currently active over the Bay of Bengal, causing warm, moist air to move towards the coast. 

Third, the jet stream's current position over Central Asia is causing increased rainfall in both India and Bangladesh. These factors, acting together with maximum force, caused a record-breaking rainfall of around 450 mm in 24 hours in both upstream and downstream areas, swelling the rivers. 

According to the Bangladesh Meteorological Department (BMD), as of 28 August 2024, Cumilla has recorded a cumulative precipitation of 864 mm for the month, significantly higher than the usual 347 mm for August. 

Similarly, Noakhali has experienced a staggering 1,434.9 mm of rainfall this month, compared to the normal 657 mm. Both districts have been severely affected by flooding due to this excessive rainfall. The rainfall reached a record 53-year high of 304 mm in the Parshuram upazila of Feni on August 20.

Water from the upstream mountainous terrain in Tripura reached Feni, Noakhali, and Chattogram within 5-8 hours on its way through the Gumti, Khowai, Feni, Muhuri, and other tributaries. It has been widely discussed that India, being the higher riparian country, did not share rainfall predictions and data well ahead of what turned into a disaster in its lower riparian neighbourhoods. 

It has also been questioned on what grounds India, which unilaterally controls the flow of the Gumti River via the Dumbur Dam (constructed in 1974), decided to open all its gates without any prior notification. They did not even provide any information regarding the water levels retained in the dam.

With the unprecedented rainfall, the Dumbur Dam filled up quickly, reaching its capacity, and was opened late at night on 20 August  2024, for the first time in 31 years. The sudden release of a huge volume of retained water led to a surge in velocity, causing the flood to become an extremely severe disaster. 

This high-impact event resulted in both economic and non-economic loss and damage, including the collapse of several water infrastructures, i.e, the Muchapur sluice gate in Companiganj, Noakhali, and the embankments along the Sitakunda coast in Chattogram. 

According to the Ministry of Disaster Management and Relief of Bangladesh, the floods left over 10 lakh people stranded and more than 4,00,000 people in around 3,500 shelters in the 11 flood-hit districts. At least 73 upazilas have been severely impacted. Besides, the floods have caused extensive damage to fish farms and livestock, with losses estimated at Tk411 crore, according to the government. 

The floodwaters have left many people isolated and in urgent need of food, clean water, medicine, and dry clothes, particularly in remote areas where blocked roads have hampered rescue and relief efforts. The extensive damage could have been avoided if people had been informed earlier.

While both neighbours have been affected by the floods, for many Bangladeshis, the final debate centres on the existing regional tension between Bangladesh and India. With the highly unusual heavy rain, opening the gates was inevitable. 

However, whether it was done intentionally without critical information exchange or the dam gates opened on their own, triggered by an automatic process, remains unclear. Historically, India has not been friendly in terms of water sharing, which has caused people to speculate that the decision to open the dam gates was politically motivated.

The impacts were multiplied at a national level, as people from the Gomti basin had not faced a flood incident of such scale in the last few decades. It was crucial to alert them and inform them about ways to handle the situation. Besides, in our country, much of the flood management and forecasting systems have been focused on the Padma and Jamuna basins. 

The flood forecasting signals are usually technical and not comprehensible to the public. Also, the DRR measures have been mostly cyclone-centric, with limited groups and NGOs working in flood management. So, consequently, the preparations were somewhat limited to tackle such a massive downpour.

The rainfall was heavy and unprecedented, yes. But was it unpredictable? Not really. 

In fact, the forecast of heavy rainfall was vivid in various weather models from 10–15 days prior to the incident. As per sources, the Flood Forecasting and warning centre of India also did not announce any such forecast. There was a forecast of a slight rise in water level from the Flood Forecasting and Warning Center (FFWC). 

However, this information was neither effectively communicated to the public nor were sufficient measures taken by the authorities. Besides, the sudden shift of power to the interim government after August 5 and the internal unrest in the meteorological department created a temporary vacuum that hampered effective monitoring and communication at the local and national levels.

However, the Bangladesh authorities' lack of effective actions, while being one of the major reasons behind the catastrophe, doesn't absolve India of its responsibility. India has unilaterally constructed numerous dams and barrages, mostly without considering their downstream impacts on Bangladesh. 

These hydrological structures reduce rivers' natural flows while allowing the rising of riverbeds, drying of adjacent tributaries and canals, and the conversion of wetlands to fish farms and urban and peri-urban settlements. Despite being a riverine country, we were not sensitive to the issues of navigability, water flow, and discharge into the sea while constructing these infrastructures.

In an extreme climatic scenario, when the risk of dam overtopping becomes real, it is essential to start releasing the stored water, even if downstream conditions are bad. In such scenarios, saving the integrity of the dam takes priority over downstream areas, questioning the legitimacy of such control structures from a social and climate justice perspective. 

As in the case of 20 August 2024, regardless of whether the dam was opened by the authority or opened on its own, the floodwater did not wait for daylight, taking the downstream country by surprise. 

For the people living in downstream areas, such hard decisions add to their compounding plight. This incident underscores the growing obsolescence of these structures in the face of changing climate dynamics. 

Historically, dams were constructed as a structural means of flood control. In present times, most dams, large and small, were constructed to withstand a range of weather events that may no longer be the norm. 

As climate change and associated risks intensify, it raises questions about the long-term viability and effectiveness of existing water infrastructure, particularly dams. This also should bring into the discussion how the loss and damages caused by both climatic factors and other triggers like big powers' control of transboundary river flows and unplanned and unjustified development stress should be compensated.

It is important to address this interdisciplinary narrative of climatic and non-climatic drivers, i.e, climate and social justice for downstream residents, regional politics, and state-of-the-art research on projected climate change impacts on dam safety.

Geographically, more than 90% of the water flow of Bangladesh originates from India. There are almost 30 dams or barrages upstream of shared rivers with India, whereas there are no treaties regarding shared water except for the Farakka Barrage. 

But India has even breached the Farakka treaty by unilaterally withdrawing water in the dry seasons. So, not only do there need to be more comprehensive bilateral treaties to manage shared water, but also, they should also be strictly followed by both parties. 

In climatic emergencies, there should be a provision for equity and agreement between the two countries. It is also necessary to receive accurate information from India on the water flow from upstream, highlighting the need for effective regional diplomacy. 

On the negotiating ground, diplomatic pressure must be created for a bilateral treaty on transboundary rivers. Our leaders have failed miserably in protecting Bangladesh's rights to its rivers over the past decades. 

We need to develop a common national manifesto on two specific aspects: first, how to keep rivers, tributaries, and wetlands alive and flowing as we live in a living delta; second, how to fight unitedly, irrespective of differences in political opinion, to claim and establish rights over transboundary river flows.

Elmee Tabassum is a Research Assistant at Center for Participatory Research & Development (CPRD). 

Sumaiya Binte Anwar is a Program Manager at Center for Participatory Research and Development (CPRD). 

Md Shamsuddoha, a climate expert and Chief Executive of Center for Participatory Research and Development (CPRD).  He is a part-time faculty member at the Institute of Disaster Management and Vulnerability Studies (IDMVS) of Dhaka University. 

Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the opinions and views of The Business Standard.