Japan: ever taller and longer anti-tsunami walls since 2011

Japan: ever taller and longer anti-tsunami walls since 2011


Since the terrible tsunami of 2011 that triggered the Fukushima disaster, Japan has intensified the construction and reconstruction of protection on the most affected parts of its coastline. With the help of a gigantic budget, the country wants to protect itself more effectively against possible future devastating tsunamis.

The inhabitants thought they were safe
On March 11, 2011, a magnitude 9.1 earthquake struck in the Pacific Ocean about 300 km northeast of Tokyo. Less than an hour later, a tsunami hit the coastline with a wave estimated to be thirty meters high in places. The water will also have penetrated up to ten kilometers inland and caused the disappearance of at least 18,500 people. This terrible tsunami caused the second largest nuclear accident in history, behind Chernobyl in 1986.

If the main concern currently seems to be the future of the contaminated waters of Fukushima, another seems just as important: guarding against future devastating tsunamis. On March 5, 2021, AFP took stock of the situation ten years after the disaster. The publication cites the example of the small town of Taro in Iwate prefecture (northeast of the country). Before the terrible tsunami, residents thought they were safe. For local tour guide Kumido Motoda, it was even the perfect city to protect against natural disasters.

It must be said that since the end of the 19th century, this locality has been impacted several times by large-scale tsunamis. As early as 1934, the town therefore built concrete ramparts 10 m high over a distance of 2.4 km at the level of the coast. Authorities have also built 44 evacuation routes with solar-powered lighting. The goal? Allow residents to take shelter in just ten minutes. Unfortunately, the 2011 tsunami generated waves 16 m high. As a result, the waters destroyed the ramparts and washed away houses and vehicles. The human toll of the disaster in Taro stands at 140 deaths and 41 missing.

Better protect yourself in the future
Since then, the Japanese government has invested the equivalent of ten billion euros to build (and rebuild) the ramparts of the coastal regions. Soon, 430 km of continuous dikes should be completed in the three departments most affected in 2011, namely Fukushima, Iwate and Miyagi. In Taro, the walls now rise to a height of around 15m and again cover over 2km of coastline.

While the sea view is less obvious today, experts have justified the construction of the dikes. They spoke of a double protection: repelling the force of the waves while reducing the damage and giving more time to the inhabitants to shelter. In addition, these new dikes have wider bases and their interior has been strengthened. We also mention improved warning systems and optimization of evacuation routes.