Dam Break Analysis of Batu Dam Using Hec-Ras

In Malaysia, dams are commonly built because they benefit the local community in several ways, especially through agricultural production and flood control. Nevertheless, an unexpected containment breach could result in the loss of life and property in a populated area downstream due to its huge potential energy reservoir. Dam break event simulations are essential for identifying and mitigating risks associated with possible dam breaches. Batu Dam has the highest percentage of the population at risk (PAR) and most likely exposed to the flood disaster due to dam break. From flood boundary maps, it was estimated that 78% of residential areas would be affected if a dam break disaster occurs. From the simulation, the maximum depth can reach up to 18 m with an estimated flow speed between 0.2 m/s – 3 m/s. At these depth and flow speed, people may lose strength and unable to control themselves in flood and would cause death and injury. Flood arrival time took 15 to 22 hours for flooding to arrive downstream with a maximum flood depth of 5.07 m at Persiaran Jasa Utama and the highest depth of 12.62 m at Kampung Baru Batu Caves with flood velocity between 1.60 m/s to 1.46m/s. Analysis and simulation of embankment dam breach events and the resulting floods are crucial for distinguishing and mitigating dangers from potential dam failures. Accurate forecast of inundation levels and the time of flood wave arrival at downstream key places is required for the development of effective emergency response plans.