1. A disaster recovery powerhouse facing a new kind of urban flooding
Japan has become a disaster recovery powerhouse, with major progress in its initial response to earthquakes and in seismic retrofitting. At the same time, it is facing a new vulnerability: urban flooding caused by record-breaking rainfall. As these events exceed what existing infrastructure can handle, a fundamental rethink of countermeasures is needed, one that isn't bound by past rules of thumb.
2. "Watershed thinking" powered by IoT and AI
There is an urgent need to move away from the traditional approach of holding back water with dams and levees, toward a system that uses IoT and AI to manage water levels across entire river basins in a unified way. What's needed is a mindset that spreads rainfall across every available space in a city and works beyond municipal boundaries to keep damage to a minimum.
3. Using disaster tech and creating new industries
As maintaining infrastructure in depopulated areas becomes increasingly difficult, disaster prevention technology led by startups is gaining importance. Companies should not only build the latest technologies into their own BCPs (business continuity plans), but also take Japan's advanced disaster prevention know-how to the world and develop it into a new industry.
— The 2026 Kumamoto Earthquake, which registered a maximum seismic intensity of 7, has seen rapid recovery. Meanwhile, flooding in Chiba Prefecture, a key hub of the Tokyo metropolitan area, caused damage that went beyond what had been anticipated. What vulnerabilities do you think exist in Japan's proud disaster infrastructure?
Sasaki Toshinao (hereafter, Sasaki): As a reporter for the Mainichi Shimbun, I covered the Great Hanshin-Awaji Earthquake in 1995. I was sent to Ashiya the day after it struck and spent about a week reporting from the site where the Hanshin Expressway had toppled over.
At that point, only 14 years had passed since the "new seismic standards" took effect under the 1981 revision of the Building Standards Act, so few buildings met those standards.
At the scene, there were five-story buildings where only a middle floor, like the second or third, had been crushed, and buildings flattened down to about 30 centimeters were scattered around. Seeing specific floors crushed like that was beyond anything I could have imagined, and the old wooden houses nearby had collapsed as well.
Since that earthquake, though, buildings have increasingly been brought up to seismic standards, and cases of reinforced concrete buildings collapsing from the shaking itself have become quite rare.
On the other hand, the initial response back then was a problem, with delays in deploying the Self-Defense Forces and setting up a disaster response headquarters. Behind this was a long postwar stretch with few major disasters, as well as former Prime Minister Tanaka Kakuei's "Plan for Remodeling the Japanese Archipelago."
Tanaka, who was from Niigata Prefecture, championed building infrastructure across the country, including the Sea of Japan coast, once called "Ura-Nihon," or the "back side of Japan," and he contributed to Japan's economic growth. However, this policy created cozy ties between the construction industry and politics, leading to pork-barrel politics and political corruption. As a result, under the slogan "From concrete to people," the country shifted toward putting resources into education and welfare instead.
Later, under the Democratic Party of Japan government, the construction of the Yanba Dam became a political controversy. But when Typhoon Hagibis (Typhoon No. 19) struck in 2019, the Yanba Dam, which was undergoing test filling at the time, and the Watarase Retarding Basin held back huge amounts of water. This prevented the Tone River from breaching its banks, and urban areas downstream along the Edo River and the lower Tone River were spared from severe flooding. In the end, the benefits far outweighed the drawbacks.
