Metropolitan Area Outer Underground Discharge Channel

Southern Taiwan was flooded badly due to typhoon FANAPI. I remember that I saw a TV program on Discovery channel talking about Metropolitan Area Outer Underground Discharge Channel (首都圏外郭放水路, しゅとけんがいかくほうすいろ) ), also known as the G-Cans Project under the Edogawa River Office, Japan. G-Cans project is an underground water infrastructure project in Kasukabe, Saitama, Japan built for preventing overflow of the city's major waterways and rivers during rain and typhoon seasons.





総合データ
■総貯水量 670000m3
■最大排水機量 1秒間に200m3
■トンネル延長 6300ｍ
■立坑サイズ 直径30ｍ、深さ60m
■調圧水槽サイズ 長さ177ｍ、幅78ｍ、高さ25ｍ


Many photos on official website by Edogawa River Office, Japan

Other links:
Tokyo’s flood control system
Tokyo flood tunnels – G-Cans project
Tokyo won't be able to cope with Katrina-like flooding