Chinese experts say the Zipingba dam over the Minjiang River, a tributary of the Yangtze, is structurally stable and safe. A panel of engineers led by Chinese Vice Minister of Water Resources Jiao Yong made the asessment earlier today.
The official Xinhua News Agency said 2,000 troops were sent to work on the dam yesterday.
The dam was completed in 2006, and is one of China's most modern. It sustained some damage during the quake, including cracks at the top and collapsed workshops. The earthquake, rated 7.8 on the Richter scale, has so far claimed close to 20,000 lives, although this figure is exected to rise.
Spillways at the dam were opened to discharge water downstream at 700 cubic meters per second to ensure the safety of Dujiangyan city downstream, which has a population of 600,000 and was severely damaged in the earthquake.
All the dam's power generating units were forced to stop.
An on-site quake control and relief efforts headquarters has been set-up, an official of the Ministry of Water Resources said.
The control headquarters has stepped-up monitoring water of inflows from the upper reaches of the Minjiang River, to limit reservoir water levels and expedite repairs on the damaged hydropower generator workshops.