Abstract
Dams play a vital role in supporting agricultural productivity, water supply and flood control in Indonesia. However, their structural failure poses serious threats to human safety and regional development. This study integrates hydrological and hydraulic modelling as part of a comprehensive disaster risk mitigation strategy, focusing on the Keureuto Dam in North Aceh, Indonesia. The dam, a 74-m-high earthfill structure with a total storage capacity of 215.94 million m3, presents significant downstream flood risk in the event of structural collapse disaster risk mitigation. Using the HEC-RAS 5.0.7 model, a dam breach scenario was simulated under overtopping conditions based on Froehlich’s empirical equations. The simulation results revealed a maximum flood depth of 19.577 m, a peak flow velocity of 1.387 m/s and an inundation area of approximately 49.91 km2 affecting 84 villages across four sub-districts.
Contribution: Beyond quantifying flood characteristics, this study emphasises a decision-support tool for disaster preparedness, enabling hazard mapping, evacuation planning and the development of early warning systems.