On June 1, the dam gate will close and the reservoir will start to fill. Water levels are expected to reach 135 metres by June 15.

As it fills, a 436-kilometre- long lake will form, stretching from the dam wall to Fengdu in Southwest China's Chongqing Municipality.

The 47-member expert panel confirmed the project was on track while at a construction site in Yichang, Central China's Hubei Province, after carefully evaluating the reservoir and ship lock from May 13 to 21.

As the world's biggest hydropower project, the Three Gorges Dam stands 185 metres high and stretches 3,035 metres.

Once the dam is completed, it will be able to store 22.1 billion cubic metres of water. The project will also reduce the frequency of major flooding downstream from once every 10 years to once every 100 years.

The Three Gorges Hydropower Station will generate 84.9 billion kilowatts a year, one-ninth of China's total energy production.

In addition, the project, which involves the installation of ship locks, will increase river shipping from 10 million to 50 million tons annually, cutting transport costs by 30 to 37 per cent. Shipping will also become safer because the gorges have been notoriously dangerous to navigate.

Since the ground-breaking project started in Sandouping near Yichang on December 14, 1994, construction has proceeded smoothly.

With an expected investment of 95.46 billion yuan (US$11.5 billion), the project will be completed in 2009.

A total of 102 million cubic metres of earth and stone will have been excavated and 27.1 million cubic metres of concrete poured.

Since the reservoir will inundate 28,753 hectares of land, over 1 million local farmers will be relocated and many cultural relics, including the 1,700-year-old Zhangfei Temple, will be moved to higher ground.

But the cultural treasure Baiheliang (White Crane Sill) - China's earliest hydraulic station located at Yibin, a city on Yangtze's upper reaches - will be submerged eventually.