In Chiba Prefecture, 884 residential buildings were flooded due to Typhoon No. 25, and drainage could not keep up around Inbanuma.

Due to the heavy rains caused by Typhoon No. 25, Chiba Prefecture announced on the 24th that a total of 884 homes (both above and below the floors) were flooded (tentative figure). 56 new buildings were added in Sakaemachi, which faces Inbanuma, where the embankment broke. In Sakura City, where the Takasaki River flowing into the swamp overflowed, 300 buildings were submerged in water up to the floor level. Narita City, which was extensively flooded, is not yet included in the tally, so the number of damaged buildings is expected to increase further. Drainage work has not been able to keep up with the swamp area, and there are still areas where the water has not receded.

10 dead, 4 missing, search continues for Typhoon No. 25 - Chiba, Kanagawa

Inbanuma, which is close to the Tone River, has suffered from flooding due to backflow from the river for many years. Due to reclamation projects, it was divided into north and west.

According to the Japan Water Agency, which has been managing water levels since 1968, the water level reached a record high of 5.04 meters at Nishi-Inbanuma in the early morning of the 22nd. This exceeded the height of 4.33 meters during the Chiba heavy rains in August. In Kita-Inbanuma, it was confirmed that the embankment had collapsed for about 100 meters. Part of the embankment of the Nagato River, which connects the marsh to the Tone River, also collapsed. According to the prefecture, this was the first collapse since the project was completed in 1969.

According to the organization, preliminary drainage began on the 17th in preparation for the approaching typhoon. The water level had fallen to 2 meters on the 20th, but the drainage could not keep up with the amount of rainfall that followed.