In December 2011, based on these policies, the Act concerning the Development of Tsunami-resistant Communities (Law No. 123 of 2011) was established to promote development of Tsunami-resistant communities based on the concept of multiple defenses. Based on the principles of “Human life is most important” and “There is no upper limit to disaster” and premised on the rule of “running away,” the concept of multiple defenses, targeting Tsunami of the largest class, combines infrastructure development and other forms of measures from the perspective of disaster reduction.

In promoting development of tsunami-resistant communities based on the Act, in accordance with basic policy formulated by the Minister of Land, Infrastructure, Transport and Tourism, the governors of prefectures assume areas that may be inundated by tsunami and the level of water that may cover these areas as a basis to implement tsunami-resistant community development plans. In conducting simulations of inundation by tsunami for such assumptions, the governors are required to make calculations on the assumption that tsunami of the largest class occurs under unfavorable conditions taking into consideration examples of dykes and levees being destroyed as found in the devastation caused by the Great East Japan Earthquake.

Based on such assumptions of inundation by tsunami, the governors are then required to draw up disaster-prevention promotion plans for municipalities under their jurisdiction, which combine infrastructure development and other forms of measures, implement projects and administrative work included in the plans, apply special measures to planned areas, and manage facilities to protect residents from tsunami. They are also required to designate tsunami disaster warning areas where warning and evacuation systems should be established and tsunami disaster special warning areas where restrictions are placed on construction of certain types of structures and development projects aimed at such construction. By combining all these measures appropriately and in a comprehensive way according to the circumstances of the communities under their jurisdiction, the governors should take measures to cope with tsunami of the largest class efficiently and effectively.

In addition, the Act creates projects to improve facilities for protecting communities from tsunami, that provide subsidies when locks, parapet levees, and other structures that utilize existing roads and railways built on the raised ground to prevent areas behind them from inundation are built or improved on certain conditions (This applies only to projects included in promotion plans as stipulated in the Act).

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## A Rapidly Increasing Number of Buildings Are Designated as Tsunami Evacuation Sites

According to a survey conducted by MLIT and the Cabinet Office, a rapidly increasing number of buildings have been designated by local governments as tsunami evacuation sites since the earthquake of March 11, 2011. The number more than doubled from 1,876 at the end of June 2011 to 3,986 at the end of October of the same year, suggesting that a growing sense of crisis was shared by coastal municipalities. In particular, the rise in the number was remarkable in such prefectures as Kanagawa, Shizuoka, and Osaka, which are concerned about tsunami caused by massive earthquakes.