Flood Risk Area

Tamagawa Flood Inundation Assumed Area

On May 30, 2016, the Ministry of Land, Infrastructure, Transport and Tourism designated and announced the "Flood Inundation Assumed Areas" for the Tamagawa, Asakawa, and Oguragawa rivers in the Tamagawa river system in the event of flooding.

• Tamagawa River Flood Inundation Area Map (PDF 5.0MB)

This map shows the results of a simulation of the areas that would be flooded and the depth of flooding in the event of the maximum expected rainfall (total rainfall of 588mm over 48 hours in the Tamagawa River basin) due to external water overflow.

Flood Inundation Simulation

You can view the simulation results of flood conditions in the event of heavy rain causing the levees of the Tamagawa, Asakawa, and Ogurigawa rivers to break.

• Tamagawa Flood Simulation (Keihin River Office)(External Link)

Inquiries about Flood Inundation Assumptions

Contact: Kanto Regional Development Bureau, Ministry of Land, Infrastructure, Transport and Tourism, Keihin River Office (Phone: 045-503-4000)

• Flood Inundation Assumed Area Map (Keihin River Office)(External Link)

Flood Prediction Areas of the Misawa River Basin and the Tsurumi River Basin

The Tokyo Metropolitan Government has published the flood prediction area maps for the Asakawa area, the Oguragawa and Misawa River basins (January 2020), and the flood prediction area map for the Tsurumigawa basin (October 2018).

• Flood Prediction Area Map for the Misawa River Basin and Tsurumi River Basin (PDF 1.6MB)

This map shows the areas and the extent of flooding that would occur due to external and internal flooding in the case of heavy rainfall of 690mm in 24 hours and 152mm in 1 hour in the Oguragawa and Misawa River basins, as well as 772mm in 24 hours and 163mm in 1 hour in the Tsurumigawa basin.
(This is created independently by Tokyo Metropolitan Government and is not based on the Flood Control Act.)

Inquiries about Flooding Predictions

Contact: Tokyo Metropolitan Government Construction Bureau River Department Planning Division Small Rivers Section (Phone: 03-5320-5414)

• Flood Prediction Area Map of the Asakawa Area, Ogurigawa, and Misawa River Basins (Tokyo Metropolitan Bureau of Construction)(External Link)
• Tsurumi River Basin Flood Prediction Area Map (Tokyo Metropolitan Bureau of Construction)(External Link)

You can check the flood inundation areas on the web version of the Inagi Hazard Map.

• Inagi Hazard Map (Web Version)