Pantnagar Journal of Research

Abstract

A dam is a construction designed to retain surface water, raising its level to ensure its availability for various needs. It serves multiple purposes, such as supplying water for irrigation, domestic and industrial use, aquaculture, and navigation. Additionally, dams effectively mitigate the risk of downstream flooding by securely containing excess water behind their walls, preventing potential destruction to lives, infrastructure, the environment, and the surrounding landscape. The present aim is to prepare a 2D model to carry out a dam breach analysis for overtopping failure of the Jamrani dam. The goal is to generate flood depth, velocity and breach outflow at various locations such as Kathgodam, Haldwani, Lalkuan and Kichha and generate an inundation map. To accomplish this objective, the dam breach model is developed using HEC-RAS software and RAS Mapper is utilized to produce a flood inundation map. To simulate the most extreme scenario, the unsteady flow condition incorporates the use of the probable maximum flood (PMF). Further, the flood wave is routed using the diffusion wave equation. The maximum breach flow produced at the locations downstream of the dam is 66283.22 m³ /s and the maximum area inundated is 464 km² for overtopping failure. Ultimately, this study aims to assist relevant authorities in formulating an emergency response plan and implementing effective measures to mitigate the impact of flooding.