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

The coastal state of Kerala, India experienced unprecedented levels of rainfall and flooding in August 2018, resulting in huge life and property loss. Since then the impact reservoir management may have had on the severity of the 2018 Kerala floods has been in question. This study presents a novel approach to developing a reservoir model using HECHMS and HEC-ResSim models, combined with satellite remote sensing data. In order to establish a link between flood severity and reservoir management, a model of the Kakki reservoir in southern Kerala was created. Simulations were carried out for six long term, two short term, and two immediate run cases. It was found that all cases except the immediate simulation run resulted in a reduced peak flow. The long simulation run, which altered the guide curve after the heavy rainfall occurring on 14th August 2018, while constraining the outflow, was found to produce the greatest reduction in peak outflow. The significant peak outflow reduction achieved suggests that improved reservoir management could have reduced the severity of the 2018 floods.