Insufficient water may make it impossible for the nation's largest hydropower project in Son La to start running at the end of this year as planned, a local weather expert said.
The Son La power plant began to receive water in mid May, but its water level was just 160 meters, below the "dead point" of 170 meters.
Nguyen Lan Chau of the Central Hydrometeorology Center said water levels have been low this year and will not improve soon due to the lack of rain. She said she was worried that Son La will not have enough water by the end of the year.
Chau also said two of the three largest hydropower reservoirs in the northern region, Hoa Binh and Tuyen Quang, have also seen water levels fall this year.
Construction of the 2,400-megawatt Son La power plant is scheduled to be completed in 2012 but its first unit is to be put on line in December.
The government in April had already forecast that lack of water in reservoirs could translate into a loss of nearly 1 billion kilowatt-hours of electricity at hydropower plants this year.
Nguyen Hong Ha, head of the Son La project, said water shortage was the "biggest difficulty" for the power plant now. However, he said he still believed that the plan to start running the plant on December 25 was viable.
The problem is that, by storing water, Son La could affect the operation of Hoa Binh power plant, which is located downstream the same river.
Hoa Binh is expected to generate 8.5 billion kilowatt-hours this year but the plant's general director, Nguyen Van Thanh, said it may have to cut the target to 7.5 billion.