This paper discusses regional cooperation and disaster management for the prevention of water-related disasters. The importance of river basin flood control has been pointed out as a countermeasure against water-related disasters, and regional planning and cooperation for river basin areas are necessary. On the other hand, in the living area, the reorganization of urban structure based on the Compact Plus Network concept assumes the factor of population decrease. Reorganization must work in conjunction with the land-use policy, such as the arrangement of urban functions and residential guidance with inter-municipal cooperation. In order to create a sustainable region, it is necessary to link ecological and watershed areas with wide-ranging cooperation in living areas, and for this purpose it is important to revisit the watershed area concept proposed in the Third National Comprehensive Development Plan. Watershed areas have the potential to link natural spaces with social and economic spaces.
