Where do Japan's giant flood tunnels send the water?
Japan's vast underground flood chambers are not simply places where water disappears. The Metropolitan Outer Area Underground Discharge Channel takes overflow from smaller rivers and carries it toward the Edogawa River, with a pressure-adjusting tank and pumping facilities along the route. Following the water makes the imposing underground rooms part of a connected drainage system.
Questions you could explore
- Why does a flood tunnel need a suitable destination as well as enough storage space?
Start reading
- Japan Ministry of Land, Infrastructure, Transport and Tourism, Edogawa River OfficeAbout the Metropolitan Outer Area Underground Discharge Channel
Identifies the contributing rivers, the Edogawa destination and the basin conditions the project addresses.
- Japan Ministry of Land, Infrastructure, Transport and Tourism, Edogawa River OfficeDraining Pump Station
Explains how water is moved from the pressure-adjusting tank into the Edogawa River and how the facilities are coordinated.
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