Half the water in the Liujiaxia Reservoir is frozen after the worst winter in 60 years, posing threat to the Liujiaxia Hydropower Station, northwest China's pivotal hydropower plant.

When the ice melt begins, the resulting flows could affect operation of the generators. The power plant was currently taking measures to prevent damaging the machines, an official of the maritime bureau of Linxia Hui Autonomous Prefecture in Gansu Province said.

"Freezing in such a large area has rarely occurred in the reservoir. This is the worst in 30 years," the spokesman added.

From mid January to early February, unusual freezing weather has gripped Gansu as the temperature around the reservoir dropped to minus 20 degrees centigrade.

The ice has also led to the suspension of the use of three piers in the reservoir areas. Local authorities have launched round-the-clock monitoring of the frozen reservoir.

The Liujiaxia Hydropower Station, on the upstream of the Yellow River, was completed in 1974 with a reserve of 5.7 billion cubic meters of water. It was the first one million kw hydropower station the country had designed and built on its own.

(Xinhua News Agency February 19, 2008)