The unprecedented heavy rainfall that occurred in western Japan in 2018 caused flooding, inundation, and sediment disasters extending over a wide area, resulting in various types of damage to lifelines, transport systems, diverse structures and so on, and exposing problems that extend across many sectors. One of the major roles of the Japan Society of Civil Engineers is to compile disaster survey data regarding the frequent occurrence of increasingly severe disasters in recent years and then share this information widely with the public. In order to contribute to the development of disaster prevention technologies and academic fields, this special issue is devoted to a collection of reports and preliminary research papers regarding the 2018 heavy rain event in western Japan. Some of the Japanese papers have been translated into English and posted on the Journal of JSCE.