Rain-related interest continues to be high, and a large flood protection facility in Tokyo, Japan, is making headlines online as heavy rains have caused heavy damage.
The Japanese government and Tokyo Metropolitan Government have built a number of large-scale reservoirs in the metropolitan area over the past few decades to prevent frequent flooding.
A representative facility is the “Metropolitan Outer Waterway”, a huge water tank located in Kasukabe City, Saitama Prefecture, north of Tokyo.
There are 59 concrete columns supporting the ceiling, so it is also called the underground temple.
Tokyo also has about 20 reservoirs, box-type storage facilities, and three underground tunnel-type storage facilities to prevent flooding in the city center.
Among them, the 'Kandagawa-Hwansang Line 7 Underground Water Storage Facility' is also a model for the Mokdong Rainwater Tunnel in Korea, and can temporarily store 540,000 tons of water.
In August 1993, during a heavy rain, more than 3,000 houses were submerged, but in October 2004, after the completion of the first phase of the facility, only 46 houses were submerged in a similar amount of heavy rain.