Whatever the thinking behind the old Kosi and Gandak agreements between Nepal and India (1954 and 1959), they have left a legacy of resentment and mistrust in Nepal which has persisted despite the amendments of 1966 and 1969. The Mahakali Treaty of 1996, signed after extensive consultations, has remained a dead letter, contributing to a worsening of India-Nepal relations rather than opening a new chapter as had been hoped. The old debate has now been revived by the breach in the Kosi embankment.
The India-Nepal relationship has been badly mismanaged on both sides. Ham-handedness and insensitivity on India's part, and excessive touchiness and readiness to misunderstand on Nepal's part, have created a convoluted and volatile relationship between the two countries, which resists repair. Perhaps the best course would be to wipe the slate clean and start afresh. There is now a new government in Nepal, and a comprehensive review of the old treaties and agreements is in any case inevitable. Why not scrap the lot and explore a new relationship? But in so doing, it might be sensible to avoid excessive intimacy and aim for no more than friendliness, correctness and a reasonable distance.
Leaving aside the urgent humanitarian challenge of relief and rehabilitation, it is also important to address the matter of dams and embankments as instruments of 'flood control'. Given the natural mass wasting of the Himalayan system and the waywardness of the Kosi due to the load of sediment it carries, it was probably a mistake to build a barrage and embankments on that river. Even if the embankment had been properly maintained, it might have given way in an exceptionally heavy flood. That is the nature of embankments: even if they do not break down, they can cause various problems, such as rises in the level of the riverbed and the consequent elevation of the river above the level of the ground on either side; possible attacks by the river further downstream; and of course the emergence of waterlogging and even flooding in the areas 'protected' by the embankments, because water cannot drain from those areas into the river. While it might not be possible to rule out the construction of embankments altogether, they are in general remedies worse than the disease.
Floods are natural phenomena. They will occur from time to time, in varying magnitudes and intensities. When the floodwaters come, the river needs space to spread and accommodate them. The natural floodplain of a river must be considered an integral part of the river. If we build on it, or if we try to contain the river within its embankments, we are asking for trouble.