The “Act for Partial Amendment of the Act on Countermeasures against Flood Damage of Specified Rivers” was enacted in November 2021. Based on this act, the Hiroshima Prefecture designated the Honkawa River as an urban river in July 2022. The Honkawa River flows through Takehara City and is a Class B river in the Honkawa River system. Majority of the Honkawa River basin is designated for land use . Therefore, this study reports its application to a specific urban river basin and the issues encountered, such as river environment improvement and basin countermeasures.

 The following conclusions were drawn: 1) The Honkawa River flood control plan incorporated the runoff control into the inland water area (land use zone). Therefore, the river and sewerage system planning is needed in the phased future improvements. 2) In basins designated as land-use zones, we are considering land use methods from a wide range of perspectives, including the designation of storage function conservation areas and construction of control areas. Therefore, there is a need to examine countermeasures while aiming to reach a consensus with local residents and businesses.