Tokyo faced crisis last Saturday, with water levels in the Tama River quickly climbing as heavy rains and winds from Typhoon Hagibis inundated the Kanto region on an unprecedented scale.
Hakone, in Kanagawa Prefecture, saw a staggering 922.5 mm of rain that day alone — three times as much as the total for the month of October of an average year.
Levees all along the Tama, which stretches over 138 kilometers between Tokyo and Kanagawa Prefecture, were designed to withstand precipitation levels seen only once in every 200 years. But at the Ishihara observation station in the capital's Chofu area, water levels had hit their highest-ever record of 6.24 meters by 11 p.m. on Saturday, far exceeding the 5.9 meters threshold the levees were built to withstand.