Severe water shortages are affecting western Japan following unusually low rainfall that began last month [1, 2].
The drought threatens regional water security and agricultural stability as dam storage rates drop to critical levels during a period of extreme heat.
Persistent high-pressure systems have suppressed precipitation across the region [1, 2]. This weather pattern has led to sharply reduced water levels in several key reservoirs. In Tottori Prefecture, the Sugawa Dam storage rate has fallen to 14.5% [1]. In Kochi Prefecture, the Saimeiura Dam reported a storage rate of 35.1% at noon on July 19 [1].
Local authorities have begun implementing water-intake restrictions in certain areas to manage the dwindling supply [1, 2]. In Saitama, restrictions have limited water intake to 10% [5].
The shortage coincides with a significant heatwave. Temperatures in Kumamoto City reached 38.7°C [1], while Hita in Oita Prefecture recorded 37.8°C [1]. The combination of high temperatures and low rainfall has accelerated the depletion of available water sources.
Visual evidence from the region underscores the severity of the crisis. At the Sugawa Dam, the water surface has dropped far below the markings on the dam wall, a reporter from TBS NEWS DIG said [3]. In other areas, the receding waters have exposed structures previously submerged, including the roof of a former town hall at the Saimeiura Dam [1].
Residents in Tottori, Kochi, Oita, and Kumamoto continue to face restrictions as authorities monitor the reservoirs [1, 2].
“The water surface has dropped far below the markings on the dam wall.”
The current crisis highlights the vulnerability of Japan's regional water infrastructure to prolonged high-pressure systems. When dam storage rates drop into the low double digits, the risk shifts from simple conservation to systemic failure in water delivery for both residential and industrial use, necessitating strict government intervention to prevent total depletion.
