Nearly 30 percent of residential districts developed in three northeastern Japan prefectures by relocating coastal households affected by a massive 2011 earthquake and tsunami disaster have been determined to be at risk of flooding, a survey by Kyodo News showed Thursday.
The findings are based on a new tsunami estimate released last year after the completion of the relocation project involving Iwate, Miyagi and Fukushima prefectures, which were hit by tsunami waves triggered by a magnitude 9.0 earthquake on March 11, 2011.
The survey was conducted in January and February, receiving responses from all 37 coastal municipalities in the three prefectures facing the Pacific Ocean.
A total of 26 municipalities have conducted the central government-subsidized project to relocate communities to higher ground or inland for disaster prevention. But 21 of them, covering 83 districts or about 30 percent of the total, were considered to fall in the newly estimated flood zone.
Around half of the districts would be submerged in waters up to 3 meters high, a depth that could flood the first floor of a house. Over 10 districts would see flood waters of 5 meters or more, capable of reaching the second floor.
Eight of the districts, including those in Kamaishi in Iwate Prefecture and Watari in Miyagi Prefecture, could see flood waters rise as high as 10 meters.
Regarding measures being taken or planned in response to the new tsunami risks, 16 municipalities cited evacuation drills, 13 mentioned the distribution of evacuation manuals and other guidance, and three said they were preparing evacuation roads. Respondents were allowed to select multiple answers to the question.
An official of one of the municipalities in Miyagi Prefecture expressed dissatisfaction with the late release of the flooding estimates, saying it came "after the completion of reconstruction projects and may negate all the efforts we have made so far."
The new tsunami estimate has shown that the three prefectures may see an area around 1.3 times greater than the 2011 disaster affected by flooding due to a potentially massive quake along the Japan and Chishima trenches off the country's northern Pacific coast as well as an earthquake around the same magnitude as the 2011 disaster.
