In considering Eco-DRR, it is important to use resources and disaster prevention techniques that make the most of the unique ecosystems of each region. The purpose of this study was to analyze the changes in the water network and its management methods since the Meiji period in Minamikomatsu, Otsu City, located at the foot of Mt. Hira. Based on a literature survey of maps and documents stored in Minamikomatsu, interviews, and field surveys, a water network map was created for each period, and the changes in the management of the water network and issues related to disaster prevention were analyzed. As a result, we were able to confirm the traditional wisdom and techniques of water use and drainage by controlling water intake. On the other hand, the system of water network management has changed with the development of government, agriculture, tourism, and residential areas, and integrated management has become difficult. In addition, changes in the shape and flow of waterways and their disappearance have impeded and fragmented the flow in downstream areas, creating problems for disaster prevention. In the future, it will be important to secure and regenerate the continuity of water networks for watershed basin water control, and to establish a comprehensive water network management system
