Journal of Korean Society of Agricultural Engineers ISSN:1738-3692(Print) 2093-7709(Online) 한국농공학회논문집

Agricultural reservoirs in Korea have traditionally been managed primarily for irrigation purposes. However, the increasing frequency and intensity of extreme rainfall events driven by climate change have heightened concerns about the potential role of reservoirs in aggravating downstream flooding. In response, the Ministry of Agriculture, Food and Rural Affairs introduced the concept of flood-season managed water levels to promote integrated strategies for both flood control and irrigation supply. This study proposes a practical framework for determining operational rules and optimal management water levels for reservoirs under the jurisdiction of the Korea Rural Community Corporation (KRC) during the flood season. The concept of equivalent rainfall—defined as the maximum rainfall volume that can be fully stored in a reservoir—is applied to evaluate the adequacy of current management criteria. Representative reservoirs were grouped into upper, middle, and lower categories based on their storage-to-drainage area ratios. For each group, corresponding rainfall–storage volume–management water level (R–S–M) curves were developed. These curves were then used to analyze the effectiveness of different pre-release strategies and their implications for post-flood irrigation reliability. Based on the findings, reservoir-specific management water levels are recommended to enhance the flood-season operational efficiency while ensuring adequate irrigation supply.