"160 Cars Submerged" in a Flooded Underground Parking Lot: The Reality Exposed by Heavy Rain in Yokkaichi—No Coverage from Compulsory Insurance, Water Barriers Exceeded Expectations, How to Prepare

On the night of September 12, Yokkaichi City in Mie Prefecture experienced a record-breaking torrential rain with 123.5mm falling in one hour. This led to the flooding of the underground parking lot "Kusunoki Parking" near Kintetsu Yokkaichi Station. Initially, it was reported that there were "more than 160 vehicles" on the first basement level, and the second basement level was submerged up to the ceiling. Upon further inspection, it was confirmed that there were 160 vehicles on the first basement level and 114 on the second, totaling 274 affected vehicles. Drainage efforts continued throughout the night, carefully discharging water that reached a maximum depth of 5.1 meters into the sewage system. No injuries have been reported. The main issue now is compensation. Japan's compulsory automobile liability insurance covers only personal injury, excluding property damage such as vehicle flooding. Recovery from the damage hinges on optional vehicle insurance (including coverage for wind and flood damage), but coverage depends on the policy details. Additionally, the national guidelines state that flood barriers are less effective when "the flood depth exceeds the side walls of the entrance," highlighting the limitations of the facilities in extreme rain events like this one. This article organizes the facts, compensation mechanisms, facility liability issues, and preventive measures and practical responses based on primary information and official documents.