An investigation into the impact of reservoir management Kerala floods 2018: A case study of the Kakki reservoir

The paper examines the role of reservoir management in the severe flooding experienced in Kerala, India, during August 2018, focusing on the Kakki reservoir in the Pamba River basin. The study was motivated by widespread debate over whether reservoir operations exacerbated flood impacts during the event, which followed exceptionally intense monsoon rainfall. Using a case study approach, the authors aim to quantitatively assess whether improved reservoir management could have reduced downstream flood severity.

The study develops an integrated hydrological and reservoir model by combining HEC-HMS and HEC-ResSim with satellite-derived rainfall and topographic data. Multiple simulation scenarios are tested, including long-term, short-term, and immediate operational adjustments prior to peak rainfall. These scenarios evaluate changes in guide curves, release rules, and storage utilization to assess their effects on peak reservoir outflows during the flood event.

The results indicate that alternative reservoir management strategies—particularly early release of water and effective use of flood control storage—could have significantly reduced peak outflows without compromising the reservoir’s primary functions. The findings suggest that improved coordination, advance rainfall forecasting, and adaptive reservoir operation could play an important role in reducing flood risk. Overall, the paper contributes evidence to discussions on flood risk management and the role of reservoir operations in mitigating extreme hydro-meteorological events.