Onsen Tank System
Gero Onsen is one of Japan’s leading hot spring towns. Its popularity became well-established in the 1960s when visitor numbers surged as the postwar economy flourished. Many new hot spring accommodations opened during that era, and individual establishments each tapped a separate hot spring source. This rapidly depleted the waters and led to concerns about sustainability. A conservation association was formed in 1969 to investigate the issue and find a solution.
Since 1974, the city of Gero has managed its hot springs through a centralized tank system. There are seven separate tanks in operation, each with a capacity of 200 to 300 tons. The entire system has more than 10,000 meters of piping and draws from 12 hot spring sources. Collectively, the tanks provide up to 3,400 liters of water per minute for commercial and private usage. This is a dramatic reduction in water usage compared to 1970, when 42 sources were tapped to pump more than 7,150 liters per minute.
For a small fee, individuals may visit the pump system at their local tank and obtain water from the hot springs for household needs. On average, more than a hundred residents make a trip to their nearest tank each day. The onsen tank system of Gero is an example of sustainability consciousness and collective action to conserve natural resources.
