The final part of concrete placement for the main section of the mammoth Three Gorges Dam started at 4:00 a.m. on Friday in the middle reach of the Yangtze River, the longest in China.

The final concrete placement is due to finish on Saturday, which will mark the completion of the dam's main wall.

The 185-meter-high and 2,309-meter-long Dam, often compared to the Great Wall in its scale, is the world's largest dam of reinforced concrete, with a total of 28 million cubic meters of concrete to be poured. The last placement involves 1,017.5 cubic meters of concrete.

Actually, the completed section of the dam's main wall is 184.8 meters high, with the remaining 0.2 meters reserved for building the highway on the top of the dam.

Situated near the Xiling Gorge, the easternmost gorge of the Three Gorges, the Three Gorges Project is the largest water control project in the world.

Initially envisioned by Sun Yat-sen, the forerunner of China's democratic revolution, in 1918, the project has undergone protracted debates before it was approved by the National People's Congress, China's top legislature, in 1992.

Launched in 1993,the Three Gorges Project, with an estimated investment of 203.9 billion yuan (25.2 billion U.S.dollars), will have 26 generators with a combined generating capacity of 18.2 million kilowatts. The entire Project is scheduled for completion in 2009 and by then, it will be able to generate 84.7 billion kwh of electricity annually.

The Three Gorges, which consist of Qutang, Wuxia and Xiling Gorges, extend for about 200 km on the upper reach of the Yangtze. They have become a popular world-class tourist destination noted for beautiful natural landscape and a great number of historical and cultural relics.

Apart from generating clean energy, the landscape-altering mega project, with a designed water storage capacity of 39.3 billion cubic meters, will also function to harness flooding and benefit shipping.

A total of 1.13 million people have been relocated to make way for the project.

Editor: Yan