Against the Rhythm of the City--Nagoya's Water Reuse Project -April 1995

Against the Rhythm of the City--Nagoya's Water Reuse Project -April 1995

At the time of 1995, Japan was going through a period of rapid economic growth, followed by the bursting of the bubble economy, and was entering an era in which harmony between the environment and the economy was required. In urban areas in particular, the concentration of population and industrialization were putting pressure on resources, and securing water resources had become an urgent issue. Against this backdrop, the city of Nagoya in Aichi Prefecture embarked on the introduction of a sewage reuse system called "chusui" for the effective utilization of water resources.

This chusui (gray water supply) system highly treats sewage water, including domestic and industrial wastewater, and reuses it for cooling water in factories, sprinkling water in parks, cleaning water, and other purposes. Although not suitable for drinking, it was an advanced initiative to make it function as a new water source by limiting its use. Nagoya City supplied this gray water mainly to industrial areas, parks, and purification centers in Minato and Nakagawa wards, realizing its use in the order of tens of millions of liters per year.

At that time, the City of Nagoya, led by its Environment Bureau, was also engaged in educational activities to educate the public, including the establishment of a tour route to the water purification plants and chusui treatment facilities. The benefits of introducing chusui were also promoted to companies, and incentive measures such as discounted rates were introduced to encourage their use. This project is positioned at the nexus of the "sustainable development" philosophy that has been growing since the Earth Summit in 1992 and the concrete implementation of this philosophy by the government.

Furthermore, the introduction of gray water attracted nationwide interest, with Fukuoka City and Yokohama City following suit. At a time when the relationship between cities and water was being redefined, Nagoya's challenge is a symbolic example of the intersection of innovation in living infrastructure and growing environmental awareness. The challenge of balancing convenience of living with environmental preservation, an attempt to look to the future while defying the "rhythm of the city," is still highly suggestive.