TOKYO, Jan 31 (News On Japan) - A prolonged stretch of unusually dry weather, described as a “once-in-30-years” event, has led to worsening water shortages across parts of eastern Japan, prompting local governments to urge residents to conserve water as reservoir levels fall to historic lows.
Along the Pacific coast of eastern Japan, rainfall has been scarce for weeks, and the impact is now being felt most acutely in water supply systems. Even as Tokyo endured severe midwinter cold again today, rain has been notably absent. Yoshinori Oikawa, head of the Japan Meteorological Agency’s Abnormal Weather Information Center, said the region is experiencing “a marked lack of rainfall that occurs roughly once every 30 years.”
Rainfall data from the past month shows persistently dry conditions along the Pacific side, and the effects are visible at dams that supply drinking water. At the Okutama-based Ogouchi Dam, which can store enough water to supply Tokyo for about 40 days and is often referred to as the capital’s main reservoir, water levels have dropped sharply, exposing land that is normally submerged.
Takuya Tasaki of the Tokyo Metropolitan Government’s Bureau of Waterworks said the reservoir’s storage rate has fallen to 45.3%, below 60% of the seasonal average, with water levels more than 20 meters lower than normal. Compared with footage from three years ago, today’s images show a dramatic decline, with storage volumes dropping below the lowest levels recorded since the Heisei era. In response, the Tokyo Metropolitan Government has called on residents to conserve water.
Governor Yuriko Koike urged cooperation, saying, “I ask all Tokyo residents to use water carefully.” While officials say there is no immediate risk of water outages, they are encouraging everyday conservation efforts such as turning off the shower when not in use.
In Ibaraki Prefecture’s Mito city, the prolonged dry spell is having a different effect. Although tap water appears normal, some residents have reported an unusual taste and smell. A reporter who sampled the water noted a faint, earthy flavor. By today, the city had received about 40 inquiries from residents complaining of moldy or soil-like odors in their tap water.
The Mito City Waterworks Bureau explained that when river levels drop due to prolonged dry conditions, certain types of phytoplankton can grow on riverbeds and release substances that cause musty odors. Officials say the water is safe to drink and poses no health risk, but the smell cannot be completely eliminated until substantial rainfall returns.
According to the Japan Meteorological Agency, there is little chance of significant rainfall over the coming month, suggesting that the impact on daily life from the ongoing dry conditions is likely to continue for some time.
Source: TBS














