Tochigi Prefectural authorities issued a level-5 "Emergency Safety Assurance" alert for parts of Ashikaga and Sano cities on July 17 [1].
The highest alert level indicates an immediate threat to life, requiring residents to take urgent action to ensure their safety as flooding and landslides occur.
The emergency measures follow extremely heavy localized rain that occurred between July 17 and early July 18 [2]. Meteorological data showed record-high hourly rainfall, with Kiryu in Gunma Prefecture recording 72.5 mm [3] and Hachioji in Tokyo recording 64.0 mm [3].
In Tochigi, the Flag River exceeded its flood-occurrence level, contributing to widespread instability. The level-5 alert specifically covers the Keno and Tomita districts of Ashikaga City, as well as several neighborhoods in Sano City, including Kami-Hada, Shimo-Hada, Namiki, Mendori, Konaka, Murakami, and Takahashi [3].
Reports from the region indicate that the weather has already caused severe structural damage. In Ashikaga, landslides sent debris into residential areas, leading to the collapse of homes [4]. Authorities said two people are missing following the landslide [4].
"An 'Emergency Safety Assurance' of alert level 5 has been issued," the Tochigi Prefectural Government said [1].
Emergency crews are working to locate the missing residents while others in the affected districts are urged to move to the highest floors of their buildings or evacuate to designated shelters immediately. Local officials continue to monitor river levels as the region deals with the aftermath of the record-breaking precipitation.
“Two people are missing after a landslide in Ashikaga.”
The issuance of a level-5 alert is the most severe warning in Japan's disaster management system, signaling that a disaster is already occurring. The record-breaking rainfall across Tochigi, Gunma, and Tokyo suggests a high-intensity weather pattern that can overwhelm standard drainage and flood defenses, increasing the risk of sudden landslides in mountainous or residential areas.
