Tokyo's Shibuya Station now equipped with anti-flooding facility

A company that has been building a number of skyscrapers around Tokyo’s Shibuya Station over the past several years has completed a huge underground facility, tasked with safeguarding the major transit hub against flooding in times of torrential rain.

The water storage facility, built by Tokyu Corp. during a 10-year project, can hold some 4,000 tons of rainwater, or enough to fill nine 25-meter swimming pools, according to the major railway and real estate business group.

The facility, located about 25 meters beneath the station’s East Exit plaza, is usually empty. But when a downpour hits the area, it is designed to collect rainwater through storm drains. Once the weather gets better, the water will be discharged into the city’s sewers via pumps.

Shibuya, known as the home of Tokyo’s youth culture and one of the city’s most bustling neighborhoods, has been undergoing large-scale redevelopment. Among buildings recently constructed around the station is the 47-story east tower of the Shibuya Scramble Square commercial and office complex.

With its famous pedestrian crossing, the area has also been a popular destination for tourists.

The name Shibuya includes the Japanese word for valley, and the area has a valley-like terrain along Shibuya River. The station, positioned at the bottom of the valley, has been hit by flooding several times in the past when central Tokyo has experienced a deluge of rain.

Tokyu invited journalists to visit the rainwater storage facility on Wednesday. Despite the cooler temperature inside, the humidity was extremely high.

“We decided to take 10 years to build this,” said a Tokyu official, explaining that the presence of a bus terminal above ground meant that “the construction had to be done at night, and little by little.”

The Tokyo metropolitan government will be in charge of the facility’s operation from the end of this month.