YICHANG - The first power unit underneath the Three Gorges Dam, the world's largest hydropower project, began generating electricity at 12 am Tuesday to better harness the water discharged during the flood season on the Yangtze River.

The 700,000 kw unit has been undergoing a test run for 72 hours and its performance is up to operating standards, said Xiang Ke with the China Three Gorges Corporation.

The construction of the underground hydropower station started in July 2001 and is expected to house six units with 700,000 kw capacity each, said Xiang.

Also, the Three Gorges Dam has begun increasing its water release to ease the severe drought plaguing downstream rice-growing areas since the Yangtze River basin received 40 percent less rainfall than the past 50-year average.

"The underground power units will be turned on and off according to the actual situation. They are built to make better use of water during the upcoming flood season," Xiang said.

The Three Gorges Project consists of a dam, a five-tier ship dock and 26 hydropower turbo-generators. The project generates electricity, controls flooding by providing storage space and adjusts shipping capacity.