An underground cathedral protecting Tokyo from floods
bbc.com
bbc.com
https://memorymulch.net/journal/2018/11/18/maoudc
It cost about 80 bucks all told and was a bit of an ordeal to organize (you need a fluent Japanese speaker), but was definitely an experience. It was a little disappointing in how limited our tour was. I get the sense that they've narrowed down the area you can wander since opening. Still, I've explored storm drains in the US quite a bit and this was a whole different level.
We caught a train out, and walked the remaining 2km to the facility.
Great to see you can get onto the floor now !
http://ninjito.com/2006-07-04 http://ninjito.com/images/2006-09-22/qx-pano-18.jpg
https://en.wikipedia.org/wiki/Metropolitan_Area_Outer_Underg...
The guide himself was free, a nice older gentleman who used to be some sort of government liason. He insisted on taking a taxi for the 2 miles from the train station to the tour though, which was pricey. But I didn't have much of a choice (despite a whole face-saving false choice he offered of walking vs taxi that was deeply emblematic of a certain strain of Japanese cultural weirdness).
You might also enjoy some of my other drain exploration shots from stateside:
Which is likely why it's a common backdrop for many a Tokusatsu shows[0]. Every season of Kamen Rider[1] -- and likely Super Sentai[2] as well; I'm not sure since that's too juvenile for my taste -- is all but guaranteed to have at least one episode filmed there.
[0] https://en.wikipedia.org/wiki/Tokusatsu
It’s a 60 year underground water infrastructure plan that’s been miraculously more or less on schedule and budget.
I agree that it is rather impressive for a long-running American construction project to be on-time and on-budget, but keep in mind that most of the project has been tunneling through very consistent bedrock with nothing in the way. Also, the McCook Reservoir mentioned in the wikipedia article as 13x10^9 liters is a former limestone quarry that they purchased and then connected to the system. The wikipedia article says it will be expanded to 38x10^9 liters by 2029. That's true... but what is really going on is that all they've done is sign a contract to buy the quarry on the other side of the highway once the stone company is done with it, perhaps around 2026 or so. Only then will they do any construction to connect it to the system. Don't get me wrong, it's a very smart move. But it's not an 11-year long project for which they have to maintain a schedule and budget.
Unfortunately I don't remember the tour specifics well enough to confirm the exact use case of the system.
It's an impressive system but there are definitely still storms large enough to overwhelm it. But, combined with the other flood defenses in the area, it has made flooding less common in all normal weather scenarios, which is a big win compared to the situation before it was built.
The rate given for the Edo Discharge Channel pumps in the article is 200 tons per second. At 5cm/hr, that's enough to drain a region 150km x 100 km, or the whole Tokyo metropolitan area.
There are other drains (like the Edo River itself) and other sources of rainfall, but based on that calculation 200 tons per second is a huge contributor to draining even a megacity.
The local energy company is also converting some artificial caves, originally dug for oil storage, to similar use: https://www.helen.fi/en/news/2018/Gigantic-cavern-heat-stora....
Reminds me of the cisterns underneath Istanbul (Constantinopolis), built by the romans.
I searched and could only find pictures of it empty.
I would anticipate that even just the air pressure that is expelled during a surge is probably enough to cause serious damage to people.
On the scale of G-cans, it's hard to know if it would be more dangerous or less dangerous..
... but yeah, now I want to see pictures of it in use :D