History of Urban Water Use in Tokyo with Focusing on Surface and Subsurface Water as Water Sources

Abstract

The purpose of this study is to organize the history of urban water use in Tokyo with focusing on two water sources: surface water and groundwater. The urban water supply-demand space in Tokyo shifted from a three-dimensional structure, including underground space, to wide-spread and two-dimensional one, excluding underground space. To foster sustainable urban water supply systems, efforts are needed to both avoid an increase in water demand and maintain local groundwater resources. Moreover, in terms of water security, at the time of disaster or water shortage, sustainable urban water supply systems should include both large-scale extensive water supply systems and locally distributed water supply systems to supplement each other.