Between the Sea and the Mountains, Where Does the Water Flow?: Wakayama and Tokushima Prefectures' Delayed Sewerage System Development Reflects the Region (1970s-1990s)

Between the Sea and the Mountains, Where Does the Water Flow?: Wakayama and Tokushima Prefectures' Delayed Sewerage System Development Reflects the Region (1970s-1990s)
During the 1980s and 1990s, Wakayama Prefecture's sewerage system penetration rate was only about 8%, while Tokushima Prefecture's was about 9%, among the lowest in Japan. This was due to a combination of structural conditions: geography, population distribution, and national policy policy. In Wakayama, the Kii Mountains occupy most of the prefecture's land, and small towns are scattered along the coast, so a huge investment was required to develop an urban-type surface sewage system. Tokushima also had many mountainous areas except for the Yoshino River basin, and settlements were widely dispersed. The national government's sewerage policy prioritized metropolitan areas with high population densities, and subsidies for rural areas came later, delaying the start of construction itself in municipalities with smaller finances. In addition, in both prefectures, the early spread of combined septic tanks in mountainous and rural areas made the need for sewerage system development
seem less urgent, as they functioned as a practical and effective means of treating domestic wastewater. In Wakayama, large-scale factories such as steel and chemical plants were treating industrial wastewater in dedicated facilities, and the linkage with domestic wastewater maintenance was weak. In Tokushima, too, urbanization was slow because of the textile and agricultural processing industries. Under these conditions, both prefectures opted for local water management that differed from the urban model, and the low diffusion rate was not merely a delay, but also an indication of a rational water treatment system rooted in the land.