Water demand and supply in large cities in Japan

After WW II, water demand in Japan for municipal and industrial use has increased drastically in those large cities and industrial regions with rapid urbanization and high economic growth. This was true especially in the decades of 1950 and 1960.Water shortage continues to be serious in some large cities in summer months. The author attempts to explain the reasons for this water shortage by explaining the relation between population growth and water demand in large cities. To meet these water shortages, there has been active development of water resources including construction of dams and saline barriers in large river basins and modernization of the water use system to increase its efficiency and re-use capacity for sewage treatment etc.At the same time, water resources development projects have been encountering various environmental problems as well as increased local protest in the 1970s. The author discusses the present dimensions of these problems and also presents several ideas regarding water resources planning for the future.