Where's the Water Going: The Reality of Water Resource Depletion and Environmental Destruction in Japan (2003-2020s)

Where's the Water Going: The Reality of Water Resource Depletion and Environmental Destruction in Japan (2003-2020s)

Japan has an annual precipitation of 660 billion m³, of which about 35% is evapotranspired, and the remaining 430 billion m³ is theoretically available water resources. However, in some regions, water resource depletion and environmental destruction are becoming increasingly serious. In the Kanto region, groundwater is being over-pumped, and land subsidence is affecting agricultural production and urban infrastructure. In particular, groundwater levels in Koto-ku, Tokyo, and Ichikawa City, Chiba Prefecture, have been declining, and measures to control subsidence since the high-growth period are once again attracting attention.

In the Shikoku region, dam management during droughts is having a serious impact on river ecosystems. In the Yoshino River system and the Dosan River, the habitat of migratory fish such as ayu (sweetfish) and eel has deteriorated due to flow adjustment by dams, and the impact on the fishing industry has also been reported. While priority is given to securing water for agriculture, there is a need to coordinate with measures to secure river flow.

Meanwhile, industrial water use is also having a significant impact on water resource management. In Nagoya and Osaka, restrictions on groundwater pumping in industrial parks have been tightened, and the use of rainwater as an alternative water source is being promoted. Companies are also actively developing technologies to address this issue. Kurita Water Industries is promoting water recycling and reuse through the development of water treatment technology, and Toyota Motor Corporation has introduced a state-of-the-art water purification system to reduce water consumption in its production processes.

The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) publishes an annual report entitled "Current Status of Water Resources in Japan" to clarify the status of water resource use and issues. The 2024 report emphasizes efforts to use water resources appropriately and to maintain the water cycle, and in particular points out the disparity in water use between urban and rural areas as an issue.

In the future, sustainable use of water resources and environmental conservation in Japan will become even more of an issue. In addition to the need for water management that is tailored to regional characteristics, there is an urgent need for companies and local governments to work together to establish a water management system based on natural cycles.

--- (Japanese only)

### Related Sources
- Ministry of the Environment "Current Status of Water Resources in Japan
- Ministry of Land, Infrastructure, Transport and Tourism "Appropriate Use of Water Resources and Water Cycle
- Kurita Water Industries "Water treatment technology and its application to industry
- Toyota Motor Corporation "Effective Use of Water Resources and Reduction of Environmental Impact
- Water resource management policies in various regions (Tokyo Metropolitan Government, Nagoya City, Osaka City, etc.)