In Tokyo, based on the Flood Control Act, areas prone to storm surge inundation are designated along the Tokyo Bay coast (Tokyo metropolitan section) that are designated as coastal areas where water levels are notified.
Following the amendment to the Flood Control Act in July 2021, other coastal areas with protected structures such as houses have also become subject to area designation. Therefore, we would like to inform you that we have designated areas prone to storm surge inundation along the coast of the Izu and Ogasawara Islands.

1．What is a storm surge inundation area?

Article 14-3 of the Flood Control Act stipulates that, in order to facilitate smooth and rapid evacuation during storm surges, areas where flooding is expected due to the largest conceivable storm surge are designated as storm surge inundation areas.
Along with designating the area, the expected water depth and duration of flooding in the event of inundation are shown on the storm surge inundation area map.

2．Viewing location

High tide inundation area maps for the coasts of the Izu and Ogasawara Islands can be viewed at the following locations and on the following website.

• Tokyo Metropolitan Government Information Room (3rd floor, south side, Tokyo Metropolitan Government Building No. 1)
• Port Authority website

• Construction Bureau homepage

Contact: Port and Harbor Bureau, Remote Island Ports Department, Planning Division Phone: 03-5320-5660 Construction Bureau, River Department, Disaster Prevention Division Phone: 03-5320-5430