Largest storm drain

The G-Cans project,which began in 1992 underneath Tokyo, Japan, is designed to prevent the flooding of the city’s waterways during Japan’s typhoon season, which reaches its peak during September. It consists of five containment silos, measuring 65 x 32 m (213 x 105 ft) connected together by 64 km (40 miles) of tunnels, as well as a huge water containment tank measuring 177 x 78 m (580 x 256 ft) and 25.4 m (83 ft 4 in) high. The system is connected to turbines that can pump 200 tonnes (44,090 lb) of water per second into the Edogawa River.