1st International Conference on Modelling and Simulation on Engineering, Science and Technology (ICOMSEST) - Kuala Lumpur - Malaysia (2019-02-24)

Flood hazard simulation of Binga Dam breach Using Hec-Ras in the Agno watershed, Benguet. Philippines
The study site is situated in barrio Binga, Itogon, Benguet Province, approximately 19 km from the Ambuklao dam, the Binga dam forms an impoundment on the Agno River. Considerable attention has been paid to Binga Dam for it is one of the oldest dams in the Philippines, having been constructed in the 1960s, and is thus susceptible to dam breaching. Binga Dam is part of the three cascading dams along Agno river, it is situated in the middle. The Binga Dam is dying and currently experiencing many problem that might result to dam failure, it is also affected by contamination of water, soil, and air from open-pit and have not been sturdy to resist or withstand currents during typhoons and earthquakes. Reservoir capacity decreases over time due to the accumulation of soil sediments upstream along Agno River. The study focused in analyzing the effects of dam overtopping and seepage or piping failure that may occur in Binga Dam and simulating the additional impact of Peak Flow from Ambuklao Dam to Binga dam. Dam breaching can highly affect the environment and the community. This is why this research study will develop a dam-break flood hazard map to Binga Dam and its vicinity by using HEC-RAS to ensure security and to be able to foresee the possible risks, like flooding, which may strike downstream communities. The usage of advanced software in dam breach analysis to determine significant data can be addressed by the technological methodologies in HEC-RAS and ArcGIS. It would be a great solution to help enhance mitigation activities in Binga Dam for disaster preparation. With the help of the different types of geographical data from ARMS(Automated Real-time Monitoring System) – Mapúa, NAMRIA (National Mapping and Resource Information Authority) and the flow data from NWRB (National Water Resources Board), the researchers produced and processed flood inundation maps considering dam breach scenario using RAS. IfSAR was used as the digital elevation model of the area. In totality, the Overtopping Failure was the most crucial type of dam failure as per the flood inundation maps produced in HEC-RAS. The additional effect of Peak Flow from Ambuklao dam was also observed and that adding its effect to the flow of water to Binga Dam during dam breach was really significant. The beneficiaries of this study are the people located near Agno River and the Dam operator itsel. The produced flood inundation map gives information to the people specifically the Local Government Units in the downstream part of Binga Dam and helped them develop emergency response to prevent catastrophic loss to human life and property.
Assist. Prof. Cris Edward Monjardin, Professor Francis Aldrine Uy, Mr. Murleif Mikhael Delos Santos, Mr. Jan Daniel Monreal, Mr. Karl Ericson Landrito, Ms. Bianca Vargas