While the local reservoirs are aging severely, the resident's living space is increasing due to the expansion of amenity space downstream of the reservoir. Additionally, damage cases due to abnormal weather occur every year due to lack of practical disaster measures. This study categorized risk characteristics based on the elapsed years and the scale of human and facility damage downstream for 13,118 reservoirs under the jurisdiction of local governments, which can provide location and attribute information. It proposed priority management strategies for each category. 9,139(69%) of the analyzed subjects were identified as priority types for facility maintenance and management, 6,044(46%) were identified as priority types for downstream damage prevention support projects, and 3,495(26%) were identified as priority types for an EAP(Emergency Action Plan). Based on this research methodology, it is necessary to analyze the potential risk characteristics of reservoirs and derive reservoirs that are deemed to need management first, and establish basic data to establish management directions for reservoirs and downstream areas.