Blog - Kowabunga, dude!

Kowabunga, dude!

On Sunday we went 50 meters (164 feet) underground Suginami-ku and visited a gigantic reservoir meant to drain water when it rains way too much. This is a last resource fall-back mechanism that's only activated when the sewer system is totally full.

The main reservoir, that takes the shape of a 2.2km tunnel of 8.5m of diameter (as high as a 3-story building), can hold up 120,000m², or the equivalent of "500 elementary school swimming pools". Ok.

After the rain has stopped and the sewers and Kanda-gawa are back to normal, the water is pumped back up 50 meters by huge pumps in two locations, and sent to the water processing center after which it's then put back into Kanda-gawa.

In our journey, we wore our blue hats into Wada pump facility, walking 14 floors down through a small staircase. There we walked through a smaller tunnel that led to the large reservoir. After some explanations, we went back near the bottom of the stairs and peeked up the "drop shaft", a vertical tube that has a screw design inside meant to carry the water smoothly down 30 meters, because if a lot of water would fall 30 meters straight it would be very loud and would also cause damage to the structure.
Then, we went up about 10 floors, this time we peeked down the drop shaft, peeked into two more tunnels that lead water here from the sewers.

Back outside, we were taught some more stuff and got freebies and some tea.

So here are some of my out-of-this-world photos. For more, check my Flickr.