### History and current status of securing water resources in Japan (1950s-2020s)

### History and current status of securing water resources in Japan (1950s-2020s)

**1950s to early 2000s: Formation of the foundation for water resources development**.
Japan's use of water resources expanded greatly along with its postwar economic growth. In order to stabilize river flows, infrastructure such as dams and weirs were constructed from the 1950s, mainly in the Tone and Yodo river systems. This enabled a stable water supply in urban areas, but as industrialization progressed, land subsidence caused by groundwater pumping and pollution of rivers and lakes became an issue.

**2010s: Deepening Water Resources Management and Technological Innovation**.
In the 2010s, sustainable use of water resources emerged as a priority issue. In Japan, water-saving technologies were introduced in the agricultural sector; for example, in the tea-growing region of Shizuoka Prefecture, a precision irrigation system successfully reduced groundwater use by about 20%. Meanwhile, in the industrial sector, Sumitomo Chemical developed a filter to purify industrial wastewater and achieved 90% reuse of wastewater in a factory area in Yokkaichi City. Furthermore, Toray's reverse osmosis (RO) membranes were widely used in water treatment facilities in Japan and abroad.

**2020s: Sustainable Water Use and International Expansion**.
In the 2020s, Japan's annual use of water resources reached approximately 78.5 billion cubic meters (14.8 billion for domestic use, 10.3 billion for industrial use, and 53.3 billion for agricultural use). With droughts occurring frequently in various regions, there is a need to improve water use efficiency.
As a corporate initiative, METAWATER Inc. is providing ceramic membrane filtration systems, which are now being adopted in Europe and Singapore. In addition, Toshiba Infrastructure Systems Co., Ltd. is developing a sewage treatment business in the Ganges River basin in India and contributing to the improvement of the local water environment.

In addition, Torishima Seisakusho has provided high-performance pumps for seawater desalination technology, which are being used in Saudi Arabia and other countries in the Middle East. In Japan, energy-efficient water treatment facilities are becoming more widespread, and the Ministry of Land, Infrastructure, Transport and Tourism is promoting decarbonization in the sewage sector.

**Future Outlook**.
The water treatment market is expected to reach 100 trillion yen globally by 2025, and Japanese technology is becoming increasingly important in the international market. Effective utilization and sustainable management of water resources are key to solving global issues.