Climate change and effectiveness of dams in flood mitigation in India

The objective of this research is to evaluate the effectiveness of dams in mitigating floods across Indian river basins under current and future climate conditions. It aims to show how reservoir storage levels, particularly when exceeding 90% capacity, significantly influence flood risks, and emphasizes the need for improved dam operations and early warning systems in a warming climate.

The findings highlight the crucial role of antecedent reservoir storage in determining the effectiveness of dams in flood mitigation under the current and future climate. For instance, during the 2024 summer monsoon season, Krishna Raja Sagar dam on Cauvery River remained full for a record 172 days. Furthermore, the dams are projected to receive highly variable and extreme inflows attributed to the precipitation changes under the warming climate. The projected increase in the magnitude and variability of inflow has been reported for different dams across the world. The combination of extreme inflow and high storage level conditions is likely to result in more intense downstream flooding