In November 2011 the Spatial Dialogues team conducted fieldwork at a number of sites in and around Tokyo including the Saitama River, Tokyo Bay and the underground water storage tanks in Saitama. All the sites are part of the social, economic and environmental uses and roles of water in Tokyo. The team collaborated with Christophe Charles and students from Musashino Arts University, Tokyo.
Sumida River, Tokyo
Tokyo has four major river systems: Tama gawa, Turumi gawa, Arakawa and Tone. Generally they collect water from the mountains in the West and drain into Tokyo bay. Flooding of these river systems was particularly common in the 1950s due to rapid urban postwar expansion. From the 1980s a program was designed to prevent the flooding of Tokyo through the design of underground river and drainage systems.The Sumida River (Sumida gawa) flows through Tokyo draining out to Tokyo Bay. The river was created after the artificial diversion of Arakawa during the Meiji period.
Saitama Underground Water Storage
The Tokyo Metropolitan Area Outer Underground Discharge Channel (shutoken gaikaku hōsuiro) in Saitama, is an undergound storage facility designed to prevent overflow and flooding during heavy rains and typhoons. See here for more details. The structure is designed to mitigate the effects of increasing urbanisation on agricultural land in the Edo gawa flood basin. The system consists of a series of network pipes and storage tanks 50m underground, and is one of the largest engineering projects of its type in the world. Fieldwork was conducted in the large concrete surge tank, which is 24.5m x 177m x 78m with 59 pillars and is designed to hold and then pump water back into the Edogawa river system.
Tokyo Bay consists of a series of artificial islands and land reclamation, some of which date from the Edo period. It is surrounded by industrial, recreational, transport and residential spaces. The topography of Tokyo has undergone a series of significant interventions starting during the Edo Tokugawa period (1603–1867), these include land reclamation around the Bay and the redirection and deepening of river channels. The changes to the river system were partly in response to the alleviation of flooding, military interests and also an expanding urbanism.