There could be several reasons behind Nepal’s sudden flooding. Excessive rainfall in upstream areas could be one factor, but the records available so far do not indicate rainfall of that magnitude. Another possible cause could be the accumulation of excess water in a glacial lake, leading to increased water pressure. Climate change is increasing this type of risk as glaciers melt.
At the same time, if dams associated with hydropower projects on mountain rivers are not properly maintained, they could collapse under the pressure of the water. When that happens, mud and large rocks can come rushing down with the water, multiplying the destructive power of the flow.
The question now is whether Bangladesh faces any similar threats or risks. We are completely free from such risks and there is another factor here that could potentially lead to a similar disaster.
In Bangladesh, particularly in the Chittagong Hill Tracts, there is accumulated seismic energy capable of generating earthquakes measuring between 8.2 and 9.0 on the Richter scale. In other words, the possibility of a major earthquake occurring in that region cannot be ruled out entirely.
If such an earthquake does occur, one of our biggest concerns would be Kaptai Lake and the dam of the Kaptai Hydroelectric Power Project. If the dam were damaged by an earthquake for any reason, particularly if it had a weak section that gave way under the force of the tremor, a huge volume of water could rapidly rush downstream.
The situation could be even more devastating if such an earthquake occurred during the monsoon season, when the volume of water in Kaptai Lake is much higher. If that enormous volume of water were suddenly released through a breached dam, the speed and force of the resulting flow could cause a major disaster in Kaptai town and surrounding areas.
Thus, just as we witnessed a sudden and destructive surge of water in Nepal, a similar risk could arise here too, albeit in a different context.
Since the dam was commissioned in 1962, it has not received sufficient attention as to whether regular maintenance and risk assessments have been carried out with such natural disasters in mind. Therefore, the maintenance of the Kaptai Dam should be treated as a matter of utmost importance. The dam is quite old and has been in operation for many decades. Its structural integrity should be assessed regularly, including checking for any cracks or weaknesses that may have developed over time.
The strength of the dam’s structure needs to be scientifically assessed. The water pressure, how that pressure is being exerted on the dam, and how much pressure the dam is capable of withstanding, all these factors need to be measured regularly.
The incident in Nepal can serve as a warning for us. Bangladesh and Nepal do not have the same geographical conditions. I am not saying that the same thing that happened there would happen here for exactly the same reasons. But we must also take into account the risk of a sudden, massive flow of water rushing downstream due to accumulated water in hilly areas, dams, earthquakes, and weaknesses in dam structures.