Assessing Dam Operations under High Water Levels by Reducing Flood Control Volume for Water Supply, Power Generation, and Flood Management

Reservoir operations primarily serve three functions: water supply, power generation, and flood control. With the increasing frequency of extreme rainfall events driven by climate change, re-evaluating storage capacity, particularly flood control volume, has become essential to optimizing multi-objective operations. This study aims to simulate changes in flood control capacities, develop an optimal operation model, and analyze trade-offs among these objectives to assess their impact on reservoir performance. The study is divided into three phases. First, the multi-objective Standard Operating Policy (SOP), based on the water mass balance equation, simulates over 30 years of historical data to benchmark water supply, power generation, and flood control. The flood control capacity is then utilized to adjust reservoir water levels within this framework. Second, the model assesses the reliability of water supply and power generation while flood risk serves as a performance metric for flood control operations. Finally, quantitative results for the three objectives are expressed in monetary terms to evaluate the impacts of flood control capacity on reservoir operations and analyze trade-offs. Results suggest that under normal conditions, raising water levels to utilize flood control storage can enhance water supply and power generation benefits while maintaining manageable flood risk. However, during critical conditions, preserving flood control capacity remains essential to mitigate potential flooding and prevent disasters. By investigating changes in reservoir operations under climate change, this study highlights how adjusting water levels influences the trade-offs and benefits of each objective. Using simulations and economic value quantification, it provides a framework for maximizing reservoir benefits under varying scenarios.