被災地の防潮堤 地域に応じた見直しが必要だ

The Yomiuri Shimbun
Seawall plans should be amended to suit the needs of local people
被災地の防潮堤　地域に応じた見直しが必要だ

Plans to build huge seawalls along the coastal areas hit hardest by the Great East Japan Earthquake have been met with staunch opposition from local residents one after another. We urge the Iwate, Miyagi and Fukushima prefectural governments to calmly reexamine their seawall plans and alter them as necessary.
　東日本大震災の被災地で、巨大な防潮堤の建設計画に住民から異論が相次いでいる。計画を冷静に再点検し、必要に応じて見直すべきだ。

In the 2011 earthquake, 60 percent of seawalls with a total length of about 300 kilometers in the three prefectures were either seriously damaged or destroyed. The central and three prefectural governments are currently pushing a project to build 390 kilometers of new seawalls with ¥800 billion from state coffers.
　大震災では、岩手、宮城、福島の３県で、計約３００キロあった防潮堤の６割が全半壊した。政府と３県は８０００億円の国費を投じ、新たに計３９０キロに及ぶ整備を進めている。

To prepare for tsunami, adequately sized seawalls must be constructed. The problem is that many communities are opposed to the project as local residents consider the proposed walls “too high.”
“[The seawalls] will leave less land available along the coasts, adversely affecting fisheries” and “They will block ocean views” are two of the opinions expressed by local residents.
　津波に備え、適切な規模の防潮堤は必要だ。問題は、住民が「防潮堤が高すぎる」として、計画に反対する地域が少なくないことだ。「海沿いの土地が減り、漁業に支障が出る」「海が見えなくなる」といった声が出ている。

Miyagi Prefecture has yet to win approval for the project from 40 of 276 communities where the construction of new seawalls is planned.
　宮城県では県が建設を計画する２７６か所のうち、約４０か所で合意を得られていない。

Compared to the Great Hanshin Earthquake, which struck mainly urban areas, the disaster-hit regions in the three Tohoku prefectures are mostly depopulated. If the fishery and tourism industries on which local residents depend decline, their livelihood would be severely affected.
　主に都市部が被災した阪神大震災と異なり、東北３県の被災地には過疎地が多い。頼みの綱の漁業や観光が振るわなくなれば、住民の生活への影響は大きい。

Prime Minister Shinzo Abe’s wife, Akie, is among those who have questioned the advisability of building such high seawalls, saying, “I’m not sure that reconstruction should be carried out in such a way that it will block ocean views.” We completely understand their concerns.
　安倍首相の昭恵夫人らが「海が見えない復興でいいのだろうか」と、防潮堤の高さに疑問を投げかけたのは理解できる。

Study cost-effectiveness

The higher the seawall is the more effective it will be as a safeguard against tsunami. But on the other hand, higher seawalls are more expensive to construct, ruin scenic views and take a toll on the environment. Such seawalls also entail higher maintenance costs. Moreover, the life of concrete seawalls is roughly 50 years, which makes rebuilding them inevitable at some point in the future.
　防潮堤は、高いほど津波の防御効果は大きいが、一方で、建設費がかさみ、周辺の景観や環境は損なわれる。維持するための補修費もかかる。コンクリート製の堤防は耐用年数が５０年程度とされ、将来的に改築は避けられない。

Also from the viewpoint of cost-effectiveness, the project should be carefully studied.
　費用対効果の観点からも慎重な検討が必要である。

Each of the three prefectures has decided on the height of the seawalls based on guidelines compiled by an examination committee of experts at the Central Disaster Management Council. The standard of seawalls in the guidelines is to protect the lives and property of local residents in the event of a huge tsunami, which can occur once in a few decades or more than a century.
　防潮堤の高さは、中央防災会議の専門調査会が示した指針に基づき、各県が決めた。数十年から百数十年に１度の頻度で起きる大津波から、住民の生命と財産を守ることが基準となっている。

Under its plan, Miyagi Prefecture will raise the height of its seawalls from the pre-disaster average of four meters to 7.5 meters. That height, however, will be insufficient to block gigantic tsunami equivalent to those in the Great East Japan Earthquake, which are said to occur once in a millennium.
　宮城県の場合、震災前に平均４メートルだった高さを、７・５メートルにまで引き上げる計画となった。
　それでも、１０００年に１度と言われる東日本大震災級の巨大津波は防げない。

Instead, the purpose of building seawalls should be to reduce the force of tsunami, thereby securing more time for residents to flee the area. It is important to ensure the construction of seawalls is a part of comprehensive measures to minimize damage from a disaster that also include the establishment of evacuation centers and routes.
　防潮堤は、津波の勢いを抑え、住民が逃げる時間をより長く確保することを目的とすべきだろう。避難場所や経路の整備などと併せ、総合的な減災対策の一環として建設することが重要だ。

Some communities have lowered the planned height of seawalls, while taking such measures as transferring houses to higher ground and building seawalls in locations further inland.
　住宅の高台移転や防潮堤の内陸移転などを組み合わせ、防潮堤を計画より低くした地区もある。

If the prefectural governments insist on keeping the planned heights and invite a backlash from local residents as a result, it will further delay work to implement disaster management measures and scuttle efforts to rebuild communities, and placing roadblocks in the path of reconstructing people’s lives.
　県側が「高さは変えられない」と主張して住民の反発を招けば、かえって防災対策は遅れる。町づくりも進まず、住民の生活再建に支障を来す。

Bearing this in mind, the prefectural governments must listen to what local residents have to say.
　そのことを念頭に、行政は住民の声に耳を傾けてもらいたい。

(From The Yomiuri Shimbun, June 23, 201