Japan, a nation grimly accustomed to natural disasters, has invested many billions of dollars in a world-class infrastructure meant to soften nature’s wrath. But with the flooding in areas across central and northern Japan in recent days, the country has been forced to examine more deeply the assumptions that undergird its flood control system.
That is raising a difficult question, for Japan and for the world: Can even the costliest systems be future-proofed in an age of storms made more powerful by climate change?
Yasuo Nihei, a professor of river engineering at the Tokyo University of Science, said that in places around Japan, “we’re observing rain of a strength that we have never experienced. When we look at the costs, I think it’s clear that flood control programs need to be accelerated.”
Even so, he said, “realistically, there will be rains you can’t defend against.”
That has not always been the view of the Japanese government. For centuries, it has seen disaster management as a problem to be solved by engineering.
After a devastating typhoon killed more than 1,200 people in the late 1950s, Japan embarked on a series of public works projects aimed at taming its many rivers. Levees and dams sprung up on nearly every river, and civil engineers sheathed long stretches of riverbeds in concrete.
While the projects have saved countless lives, they are insufficient to meet the challenge of increasingly extreme weather patterns, said Shiro Maeno, a professor of hydraulic engineering at Okayama University.
“In the current state, it wouldn’t be strange for a flood to happen anytime, anywhere,” Mr. Maeno said. “Things we never could have considered have started happening in the last few years.”