Japan opts for massive, costly sea wall to fend off tsunamis
Sendai: Four years after a towering tsunami ravaged much of Japan’s northeastern coast, efforts to fend off future disasters are focusing on a nearly 400-kilometre chain of cement sea walls, at places nearly five stories high.
Opponents of the 820 billion yen (USD 6.8 billion) plan argue that the massive concrete barriers will damage marine ecology and scenery, hinder vital fisheries and actually do little to protect residents who are mostly supposed to relocate to higher ground.
Those in favor say the sea walls are a necessary evil, and one that will provide some jobs, at least for a time.
In the northern fishing port of Osabe, Kazutoshi Musashi chafes at the 12.5-metre-high concrete barrier blocking his view of the sea.
“The reality is that it looks like the wall of a jail,” said Musashi, 46, who lived on the seaside before the tsunami struck Osabe and has moved inland since.
Pouring concrete for public works is a staple strategy for the ruling Liberal Democratic Party and its backers in big business and construction, and local officials tend to go along with such plans.
The paradox of such projects, experts say, is that while they may reduce some damage, they can foster complacency. That can be a grave risk along coastlines vulnerable to tsunamis, storm surges and other natural disasters.
At least some of the 18,500 people who died or went missing in the 2011 disasters failed to heed warnings to escape in time.
Tsuneaki Iguchi was mayor of Iwanuma, a town just south of the region’s biggest city, Sendai, when the tsunami triggered by a magnitude-9 earthquake just off the coast inundated half of its area.
A 7.2-metre-high sea wall built years earlier to help stave off erosion of Iwanuma’s beaches slowed the wall of water, as did stands of tall, thin pine trees planted along the coast.
But the tsunami still swept up to 5 kilometres inland. Passengers and staff watched from the upper floors and roof of the airport as the waves carried off cars, buildings and aircraft, smashing most homes in densely populated suburbs not far from the beach.
The city repaired the broken sea walls but doesn’t plan to make them any taller.
Instead, Iguchi was one of the first local officials to back a plan championed by former Prime Minister Morihiro Hosokawa to plant mixed forests along the coasts on tall mounds of soil or rubble, to help create a living “green wall” that would persist long after the concrete of the bigger, man-made structures has crumbled.