About the Tsurumi River ・Typical urban river ・Class One river(一級河川) Tsurumi River ・Many floods in past ・ “most dirty” river in JAPAN Information Tokyo Metropolis , City Tomohiro ATSUMI Kanagawa prefecture Kota ARAKI Length 42. 5 [km] Satoshi TOKUE Drainage Tomohiro MATSUKI 235 [km2] Keitaro MATSUMOTO basin SUZUKAKE_ DAI campus History of the Tsurumi river History of the Tsurumi river Frequently Flood - Before middle of Showa era Frequently Flood - Before middle of Showa era History of the Tsurumi river History of the Tsurumi river Water pollution – Urbanization Bad landscape – After store strengthening works What is the problem? Water Master Plan Present issues of Tsurumi river ・MdMade in 2004 • Flood of river that happens many times ・ To understand issues, manage and • Water pollution because of industrialization build facilities from the viewpoint of and urbanization good water cycle • Typical urban river ・All citizen bodies cooperate with each Needfd for comprehifldhensive flood contro l measures other “Tsurumi river basin water master plan” Water Master Plan IitdfInsisted of ma il5inly 5 par ts – Protect from floods – Recover clean and big river – Protect and keep environments – Take countermeasures in case of emergency – Come in contact alota lot http://www.ktr.mlit.go.jp/keihin/tsurumi/project/masterplan/02_ritsuan/01toha_image.htm Concrete Campaign Tsurumi River • Letʼs come in contact Multipurpose Retarding Basin • Campaign to take your rubbish home • Report about Tsurumi river Information LtiLocation KdkKodukue / TiToriyama area, Kohoku-ku, Yokohama Siz e 84 [ha] Capacity 3,900,000 [m3] Amount of About 300 flood 3 control [m /sec] Facilities Nissan Stadium soccer & baseball fields tennis court Tsurumi River Tsurumi River Multipurpose Retarding Basin Multipurpose Retarding Basin When the water level of the Tsurumi River reaches very high because of heavy rain, these areas ppgerform as the retarding basin. The overflow even get into the parking areas under the NISSAN Stadium. This multipurpose retarding basin can amass about 3,900,000 [m3] of water. Typhoon No.22, 2004 date October 9th 1,250,000 [m3] Kept capacity About 1/3 of total capacity Usually, these areas are used as the Shinyokohama Park. Restraint water People can enjoy many kind of sports in these fields and facilities. level at lower 1.5 [m] reaches Mechanism of Tsurumi River Conclusion Multipurpose Retarding Basin • Tsurumi river was known as a dirty and frequently flooding river. • People made “water maste r pl an” • Reduced danger of flood • Improved water quality • Wild a nima ls come ba ck There is an overflow levee to pour water into the retarding basin areas. • Good model of River plan The gate put on the lower reaches of the river to drain off the water when it stops raining. References http://www.ktr .mlit . go. jp/keihin/tsurumi/join/fureatte/index. htm http://www.ktr.mlit.go.jp/keihin/whole/dust/index.htm http://www.ktr.mlit.go.jp/keihin/tama/project/grade/index.htm.