flood control comment Takaaki Kato Okutama Town Okutama Associate Professor, Institute of Industrial Science, Ome City the University of Mitake Ome Conducts research on how cities and communities can reduce flood risk, not only in the event of an earthquake but also with an Okutama Lake To protect the city from typhoons and localized torrential rain, urban development Mizumoto Park eye on climate change. He holds a doctorate in Engineering. Sayama Lake Kiyose City is carried out to enhance safety in all areas of Tokyo by implementing flood control Hakonegasaki measures that address the circumstances of each area. Hamura City Tama Lake A city coexisting wisely with flood risk Mizuho Town Higashimurayama Shirako River Kita Ward Naka Hamura City Tokyo has a history of employing considerable technical musashino Ward River Hamura Higashikurume Kita-Senju Hinode Town Musashimurayama City Katsushika Ward skills to control flood risk, such as diverting the Intake Weir City (Shirako River Higashiyamato ( Arakawa Ward Ayase Fussa City Nobidome section) in the period, and excavating the Arakawa floodway Fussa City section) River Irrigation Canal Shakujii River Naka starting in 1911. And now, new challenges are being Musashi-itsukaichi E Nishitokyo Ikebukuro G riverside Tamagawajosui City River Akiruno City Toshima Ward taken up to manage flood risks that are certain to rise Kodaira City Myoshoji River Haijima Senkawajosui Taito Ward due to climate change. Tokyo, which has a wide swath Akishima Ring Road Kyu-naka Musashino No.7 Undergound Bunkyo Ward of built-up areas at sea level, is at high risk of inundation. Tachikawa City City Ueno River Naka Kokubunji City Otakanomichi Regulating Reservoir Nakano River Akishima City Mitaka Kichijoji Sumida At the same time, this expansive waterside space has Kokubunji Musashi-Sakai (Kanda River section) Shin-naka Koganei City River Sumida Ward Zenpukuji Nakano Ward River given rise to a rich culture for residents to enjoy. We Shinjuku Ward The Tama Area has various water resources including cliff lines and Tachikawa Kunitachi River F C Kokubunji Cliff line Kinshicho need to look anew at these waterside spaces and rethink Shinjuku Kunitachi City D Mitaka City Nihombashi springs, which are valuable local resources. Hino Irrigation A Ward River the relationship between rivers and urban areas for the B Mamashita Yotsuya- Canal Fuchu City Kanda River Okido Chiyoda Tokyo Edogawa next era. Creating a new culture that can coexist wisely Hino Spring Shibuya Ward Ward Chuo Ward with flood risk—one that strikes a balance between the Hino City Minato Ward Ward Kitazawa river Shibuya benefits and threats of rivers—is the right direction for the C Otakanomichi and Masugata Sengawa River Furukawa Koto A Hino Irrigation Canal E Tamagawa Josui Canal green path River Ward Pond Springs 浅川 Chofu City River future. This will probably be the only model in the world Hachioji for adapting to climate change. Takao Nogawa Hachioji City River Karasuyama river Furukawa Tama city green path Undergound Inagi City Komae City Setagaya Meguro Ward River Regulating Reservoir F Ring Road No. 7 Underground Meguro Ward Tama River Regulating Reservoir

Shinagawa Ward A man-made canal dug in 1653 to NO IMAGE B Mamashita Spring D Kokubunji Cliff Line alleviate chronic water shortages in Edo. Outer seawall CITY VIEW TOKYO Tachikawa Nobidome Machida City Shimotakaido Inner embankment Stream Stream Stream Floodgate Lock gate 119 m above sea level Ota Ward Pumping station Sluice 33 m above Tamagawa-Josui cross section. Elevation difference approx. 90 m sea level Nomi River Areas below high-water level (A.P.+2 m) G

0 5km Naka River Nanamagari bathed in the evening sun / 36 35 43km Areas below 5 m above low-water level (A.P.+5 m) Photo credit: “Naka River Nanamagari” ©Chunichi Shimbun