Public Relation

The Landmarks of Tokyo Waterworks

Tamagawa Josui

Tamagawa Josui

 Tamagawa Josui is an approximately 43km long waterway that was excavated without timbering, which stretches from Hamura to Yotsuya Okido(Yotsuya Big Wooden Water Gate). It was made for the purpose of supplying water into the city of Edo.
 In 1652, the Shogunate (Japan’s feudal government) had made a grand plan to take in the water fromTama River into Edo, and appointed Shoemon and Seiemon brothers as the construction contractors.
 TamagawaThe construction started in 1653, and it was open-cut in just 8 months. Stones and wooden gutters were installed as distribution pipes in the basement of Toranomon by June of the following year, and water was supplied to the southwest part of the city including the Edo Castle, Yotsuya, Kojimachi, the plateau area of Akasaka, Shiba, and Kyobashi area. The brothers, who served greatly for the construction, were given the surname of Tamagawa as a reward.  It was designed to make the water flow for the length of 43km by using only 92m difference in elevation. This reveals the advanced technology of that time.
 In 2003, it celebrated the 350th open-cut anniversary, and it has been designated as a national historic landmark. It functions today as a water conveyance channel for raw water supply.

General Information

Name Tamagawa Josui
Location/Access Hamura City, Fussa City, Akishima City, Tachikawa City, Kodaira City, Koganei City, Nishi-Tokyo City, Mushino City, Mitaka City, Suginami City, Setagaya City, Shibuya City
For the Walk Map please checkherePDF3.27MB)
Current Purpose
  • Upper Basin(Approx. 12km from Hamura Intake Weir to Kodaira Observation Point)
    Headrace of Raw Water Supply
  • Middle Basin(Approx. 18km from Kodaira Observation Point to Sengembashi)
    Fresh Stream Restoration Project
    (Downstream from Sakai Purification Plant)
  • Drainage
    Lower Basin(Approx. 13km from Sengembashi to Yotsuya Ookido)

●Statue of the Tamagawa Brothers

The big brother Shoemon, is holding a ”Kennawa (measuring rope)” a surveying instrument at that time, and the one sitting with the ”Kenzao (measuring rod)” is the little brother Seiemon.

Statue of the Tamagawa Brothers

PC Site