In 1991, a typhoon flooded 100 km², destroying more than 30,000 homes and killing 52 people. To prevent this, Japan began creating underground channels to avoid these floods. Thus, Tokyo and some metropolises in Japan are completely protected against floods from rain, typhoons, and tsunamis. Although the city is filled with buildings and tunnels underground, they are almost invisible to those on the surface.
One of these tunnels is the Kanda River Underground Retention Basin, 4.5km in a tunnel that is 40 meters below ground. This basin can hold up to 540 thousand tons of water when Tokyo is hit by floods. In Osaka, we have the Hiranogawa reservoir, which is 1.9km long to prevent flooding. There are several other smaller underground facilities, but today we will talk about the largest in the world.
G-Cans - The Underground Temple
There are underground constructions in Tokyo that started in the 90s and have pillars weighing 500 tons. In this case, we are talking about the G-Cans Project, an underground facility to divert water from Tokyo to the Edogawa River. This facility has turbines and 78 pumps capable of draining more than 200 tons of water per second. There are 6.4 km of tunnels, 50 meters below the surface, and it cost over 3 billion to build.
The site is used a few times a year, you can visit this underground temple for free from Tuesday to Friday for an hour and a half. For this you must register in advance on the website below. We will also leave the address of the place.
- www.ktr.mlit.go.jp/edogawa/gaikaku/english/index.html
- Address: 2º Andar na recepção do Ryukyukan, 720 Kamikanasaki, cidade de Kasukabe, Saitama 344-0111
- Phone: +81 48-746-0748
