The Kanto region may experience a serious drought this summer, possibly triggering a raft of restrictions, due to an “unprecedented” shortage of water in lakes and reservoirs supplying the area, officials warned Tuesday.
Although the region expects decent rainfall over the next few days, hopes remain slim that it will significantly alter the dire forecast, they said.
Officials have already imposed a 10 percent restriction on water intake for six prefectures around the Tone River, while a 20 percent restriction is in place for cities drawing from the Watarase River.
At 20 percent, fountains in parks can be temporarily switched off, while a 30 percent curb might lead to school swimming pools being closed or temporary restrictions on households.
“We have seen an unprecedented rapid drop in water reservoir levels” in eight water storage areas located along the Tone River, said Takaharu Masaki, an official in the water management division of the land ministry.
The Tone River is Japan’s second-longest river and the biggest by drainage area, passing through a swath of the Kanto region from Gunma Prefecture in the west to Chiba Prefecture in the east.
The eight reservoirs, which play a vital role in supplying water to Kanto residents, have witnessed a marked shortage of water this year due mainly to unusually low snowfall last winter and a lack of any substantial rain in the subsequent months.
“If the situation continues until August, things will be quite tough,” Masaki said.
As of Tuesday, the eight reservoirs were at 39 percent of capacity. This, according to Masaki, is 54 percent of the average for the same time in previous years and the lowest level in 25 years.
The situation has grown so dire, he said, that only severe weather events such as typhoon-driven torrential rains will arrest the trend.
Japan last experienced a water shortage this severe in summer 1996, when households in such prefectures as Chiba and Saitama faced restrictions on daily water use. During a drought in 1994, some swimming pool operators in Tokyo were instructed to conserve water.
On June 16, a committee set up to battle the water shortage, whose members include officials from the land ministry and local governments in Tokyo, Chiba, Saitama, Ibaraki, Gunma and Tochigi prefectures, agreed on a 10 percent restriction in water intake from the Tone River.
On Saturday, a separate land ministry-led committee decided on a 20 percent curb on water intake from the Watarase River, affecting some cities in Tochigi and Gunma prefectures.
Masaki said the 10 percent restriction is unlikely to have a significant impact on residents.
He said a 20 percent limit could lead to fountains in parks being temporarily switched off.
Eventually, a 30 percent restriction on water intake — equivalent to the level seen in 1994 and 1996 — could befall Kanto, possibly resulting in school pool closures and temporary restrictions on households, said Hironori Ota, an official in the land ministry.
But he added that compared with two decades ago, water suppliers have improved storage capacity and are likely to better handle the 30 percent restriction.
Nevertheless, a repeat of conditions experienced during the 1994 drought can’t be ruled out, Ota said.
“We’re far from being optimistic,” he said.
The Meteorological Agency predicts it will rain for the next few days in the Kanto region, but both Ota and Masaki said the rainfall will do little to fundamentally improve the situation.
“The best it will do is to slow down the decrease of water in the dams, but no, it won’t turn things around,” Masaki said, adding the nearby mountains will absorb the rain first before it gets caught in the lakes behind the dams.