China's Three Gorges Dam began to fill as its sluice gates started closing from 9 am on June 1.

The sluice gates at the dam in Yichang, Central China's Hubei Province, have begun blocking the flood-prone Yangtze River to form what will become a huge 600-kilometer-long reservoir.

The water level will rise from the current 100 meters to 135 meters by June 15. The water levels behind the dam will by then be 65 meters higher than those of the river downstream, laying the foundation for hydro-electric power generation.

The storing of water in the dam is a milestone in the development of the world's largest hydropower project, which will be completed in 2009.

Navigation on the Three Gorges section of the Yangtze River, which was prohibited for 52 days, will resume on June 16 as the permanent ship lock at the middle reaches of the Yangtze River begins trial operations. Larger ships will be able to traverse the dam to the river upstream.

Since construction began on the project in 1993, the multi-billion-dollar scheme has progressed on schedule, with phase two due for completion by the end of this year.

And two hydropower generating units, each with a capacity of 700,000 kilowatts, will start up in August. Another two will begin operating in October.

A total of 5.5 billion kilowatt-hours of electricity will be produced this year by the project.

The power will be delivered to energy-starved cities in Central and East China this year, including Shanghai and Wuhan, said Lu Youmei, president of the China Three Gorges Project Corp (CTGCC), which owns and is developing the scheme.

The project is due for completion in six years. Over the six years, the dam water level is expected to reach 175 meters and another 12 power generators will start work. By 2009, 26 power generating units will have a total capacity of 18.2 million kilowatts.

Lu said the project could come within its budget of 203.5 billion yuan (US$24.57 billion).