Explore the huge sewer system in Tokyo

Flood drainage system in the heart of Tokyo, Japan is the largest underground sewer in the world, with huge vertical wells and more than 70 large capacity pumps.

Huge sewer system in the heart of Tokyo

The drainage system was built 50 meters deep under a football field and park on the outskirts of Tokyo.Work started in 1992, completed in 2009.

The underground sewer system consists of 5 large concrete wells, 65m high and 32m in diameter, connected by a 6.4 km long tunnel system.

In the picture is a diagram of the sewer operation system.Water from the ground flows down to 4 vertical wells, through the drain, and is pumped out.

The highlight of the project is the pressurized tower called "The underground palace" 177 m long, 78 m wide, 25.4 m high.

In the picture is "Underground Temple" consisting of 59 reinforced concrete columns, each can support 500 tons of ceiling weight.

In the picture is the No. 1 stand.

An engineer is going to check the sewer system.

The wells stand as a giant nozzle, collecting water from four large rivers that flow into Tokyo, then being drained into the Edo River.

Pump room in the sewer system.The pump system has 78 machines, 10 MW capacity, can pump 200 tons of water (203 m3) to the Edo River every second, equivalent to the water volume of a standard 25 m swimming pool.

In the picture is the No. 3 well. This work is used about every 7 years to protect Tokyo from flooding.This also becomes an interesting attraction for visitors to Tokyo.