The water level upstream of the Hong (Red) River in northern Vietnam started rising fast Sunday morning and some areas became flooded, as China had released a large amount of water from the reservoirs of its hydropower plants.
According to the Central Hydrometeorology Center, the water level of the river in Lao Cai Province surged quickly and reached its peak of 81.41 meters at 2:00 pm yesterday, before lowering to 81.34 meters an hour later.
In Yen Bai Province, some 150km from Hanoi, the water level of the Hong River was measured at 30m.
A weather forecast of the center at 9:30 pm yesterday said that floodwaters would continue inundating the areas upstream of the Hong River so its water level would rise.
Early on Monday, the water level rose to 31.7m in Yen Bai and 17.5m in Phu Tho.
At 7:00 am today, the water level of the Hong River in Hanoi reached around 3.4m. It was only 2.6m on Sunday morning.
Luu Minh Hai, director of the Hydrometeorology Center of Lao Cai Province, which borders China, said his agency and its counterpart from Yunnan Province notifies each other four times a day of any change in the water level.
However, the information exchanged is only for the water level, which does not include anything about China discharging reservoir water.
The Lao Cai agency warned that flash floods may hit many localities along the Hong River.
Dao Trong Tu, from the Vietnam River Networks, said the hydrometeorology agency of Yunnan announced that it would release water at 2,500 cubic meters per second from a reservoir in the Chinese province, some 200km upstream of Lao Cai.
The release of water started at 1:00 am on October 11.
The areas upstream of the Hong River section in China have two major hydroelectricity plants: Namsa with its reservoir able to contain 260 million cubic meters of water and Madusan, 551 million cubic meters of water.
In addition, China has around 20 dikes of different sizes upstream of the Hong River section in Vietnam.
Those reservoirs and dikes in China are capable of holding 49 percent of the water volume of the Hong River section in Vietnam, according to Tu.
The facilities can create a lot of trouble for Vietnam if they release water at the same time.
Tu noted China has rarely shared information on most of the operations of its reservoirs and dikes upstream of the Hong River with Vietnam.
“We need to set up a mechanism of coordination with China regarding this issue,” he suggested.