Playback ’94] The “Drought of the Heisei Era” that Dried Up Kagawa Prefecture with “0% Water Reservoir”: The Looming Crisis in the Tokyo Metropolitan Area

In the Tokyo metropolitan area, water withdrawal restrictions of 10% will be implemented in the Tone River system from the 2nd. The reservoir level of the Yagisawa Dam in Gunma Prefecture is 19% as of the 20th, and the lake level has dropped 25 meters. The water supply for Tokyo residents is currently being supplemented by the Tama River system, which is also at 75% (as of January 20), and the Tokyo Metropolitan Government has set up a drought task force for the first time in four years.

The cause is a dry rainy season. If Tokyo were to become like Takamatsu, there have been no water trucks since the Tokyo Olympics, and we do not have much experience with droughts, so we cannot predict what kind of panic there will be” (River Coordination Division, Kanto Regional Construction Bureau).

According to the Japan Meteorological Agency, the forecast was for clear skies and low rainfall through August. There is a good chance that Tokyo will become a “desert” as well.

In the summer of 1994, water withdrawal was restricted in the Tone River system from July 22 to September 19. The Tokyo Metropolitan Government also restricted water supply by up to 15% from July 29 to September 8, but water was not cut off in the Kanto region except in some areas.

In Shikoku, Typhoon No. 7 made landfall on July 25, 1994, dumping heavy rain in the Shikoku region, which temporarily restored the dam’s water storage capacity slightly, but another heat wave finally brought the Hayamoura Dam’s water storage capacity to 0% on August 19. In Takamatsu City, the water supply was cut off until September 30. The most prolonged drought was in Fukuoka City, where the water level in the city’s dams had recovered to only about 30% by October 1994, and water was cut off for 295 days until June of the following year.

The drought is said to have been caused by an increase in the population using water and climate change due to global warming. In recent years, the effects of global warming have been more often associated with extreme heat and guerrilla downpours. In 2009, however, Hokkaido experienced a once-in-a-century drought that caused damage to crops. Japan is said to be a land of abundant rainfall, but its rivers are short and fast-flowing, making it difficult to secure water resources. One never knows when extreme weather conditions will bring another drought.