The underground cathedral protecting Tokyo from floods

[deja vu]

http://www.bbc.com/future/story/2018112 ... rom-floods

Cecilia Tortajada recalls making her way down a long staircase and into of one of Japan’s engineering marvels, an enormous water tank that
crowns Tokyo’s defences against flooding. When she finally reached the tank’s ground, she stood among the dozens of 500-tonne pillars supporting the
ceiling. In the cavernous, shrine-like cistern, she felt humbled.

“You find yourself being a tiny part of this humongous system,” recalls Tortajada, a water management expert at Lee Kuan Yew School of Public Policy’s
Institute of Water Policy, in Singapore. “You realise how well prepared Tokyo is.”

I saw the TV special on this. The flood system is enourmous, but it may not be enough in the future. Some of it's low lying coastline may have to disappear
to save the city.

[CielOnTap]

Thirteen years' time to make that underground tank! What stuns beyond the vastness and tallness of the tank is the lack of any emergency flotation rafts or equipment on the pillars. I'd think that tank staff would be aware of when not to be down below during a water situation needing the tank's facility to redirect water.