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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.

5–7 min

Questions you could explore

  • Why does a flood tunnel need a suitable destination as well as enough storage space?

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3–5 min
Where do Japan's giant flood tunnels send the water? | Speech Topic | speaking.app