Abstract. The implications of forecast-based reservoir operation have been considered to be innovative approaches to water management. Despite the advantages of forecast-based operations, climate-related uncertainty may discourage the utilization of forecast-based reservoir operation in water resources management. To mitigate this concern, a systematic evaluation proves helpful. This study presents an evaluation framework for reservoir management under a variety of potential climate conditions. In particular, this study uses Monte Carlo simulations to quantify the robustness of the forecast-based operation in a scenario of degraded ability of forecast skill, and demonstrates a new performance metric for robustness. This framework is described in a case study for a water supply facility in South Korea. To illustrate the framework, this study also proposes dynamic reservoir operation rules for our case study, utilizing seasonal climate information and a real-option instrument from an interconnected water system. Results provide system robustness evaluated over a wide range of defined uncertainties related to climate change. Results also suggest that the dynamic operation management adopted in this study can substantially improve reservoir performance for future climates compared to current operation management. This analysis may serve as a useful guideline to adopt dynamic management of reservoir operation for water supply systems in South Korea and other regions.