After going on the Ryukyukan tour of the G-CANS water tank and learning about flood control in Tokyo, I was surprised to learn about park being used as flood control. Several parks in and around Tokyo are designed to be flood basins. The design is meant to hold as much water as possible so that surrounding areas can either be protected or given enough time to evacuate. While not all parks are designed to be part of the flood control system, enough are designed in this way. The next time you are in a park in Tokyo, or anywhere else in Japan, look around and observe the gradient. If you feel as if the park was designed like a bowl, then chances are its secondary purpose is as flood control. The next time there is a heavy rain and you see a park flooding in Japan, realize that it just might be designed that way to protect you and the neighbourhood you are in.