Even if a multi-purpose dam is operated with due regard for flood control, and the flood cushion is maintained, the moderation that this can offer is very limited. The contingency of heavy floods posing a danger to the dam and compelling the opening of the gates is always present. The question is whether a limited protection under normal circumstances is worth the risk involved in non-normal circumstances. This is an inherent danger in all dams, and all the greater in the case of Himalayan rivers.

It is hoped that the expression ‘fallacy of flood control’ stands justified, though one is open to correction. What then must we do? We can learn to cope with floods, and perhaps even benefit from the silt that they bring. They could be anticipated and prepared for; there could be timely information, a state of readiness for an emergency, the minimisation of damage and prompt response by way of relief. That is what we try to do in the case of earthquakes or tsunamis: floods call for exactly the same approach.

The writer is an honorary research professor at the Centre for Policy Research