The inhabitants of Tokyo are protected from flooding with an impressive complex of underground tunnels to discharge the water. Journalists from CNN described the system as worthy of a science fiction movie.
Tunnels demonstrates how the administration of Tokyo, located in a high risk area of flooding and tropical cyclones, is trying to keep safe the 13 million inhabitants of the metropolis.
Usually kept secret from the public, the ensemble was visited Thursday by journalists from CNN, which were accompanied by engineers on a tour of the Water Discharge Tunnel.
Lying on the outskirts of the capital of Japan, behind a small government building and beneath a football field and a skateboard park, the architectural ensemble is so little visible that anyone can pass it a dozen times the entry without even notice it.
Built between 1993 and 2006 with nearly $3 billion the complex is more impressive than its name suggests, said the journalists from the television station.
Once they went down on a series of massive spiral stairs, they reached a hall of stunning dimensions they likened to the Greek temple Parthenon, an underground version, as the environment seemed, in their opinion, “out of a science fiction movie”.
The first water tank covers more than 97 meters in length and is higher than a five-storey building. The complex is comprised of five such large tanks capable of eliminating water over a tunnel about 6,5 km long.
In this area of Saitama Prefecture, torrential rains used to flood the Naka River basin, which the authorities hope to control by the incredible drainage system located underground.
When the water comes to fill the tanks and tunnels, engineers can access the system in its heart. There is a series of four turbines powered by jet engines similar to the equipment of a Boeing 737 aircraft. Turbines will channel the flood water to another river, Edo.
This portion of the Tokyo underground can not be compared to that of New York, a labyrinth of tunnels, drainage systems and supply lines, consider journalists from CNN.
In this sense, Japanese engineers are the first to indicate that the system developed by them, though remarkable, is designed to cope with heavy rains, but a storm such as Hurricane Sandy is a challenge which is hard to defend against.
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