The Three Gorges Project Development Corporation has announced that the sluice gate will be closed at the main dam on June 1 to begin storing water.
The water level at the dam is scheduled to hit an altitude of 135 meters on June 15, 55 meters higher than the current level.
The concrete dam wall now stands at an altitude of 140 meters.
The water storage process is divided into three phases. During the first phase, to be completed by June 15, the water level will be raised to 135 meters. As the construction of the dam continues, the water level is scheduled to be further elevated to 150 meters by September 2003, and to 175 meters in 2009 at the completion of the project.
To make way for increased flooding, more than 380,000 people living in the area have been relocated. A clean-up of the reservoir bottom has also been completed.
Construction of the Three Gorges Project began in 1993 and is expected to finish in 2009, when 26 power generating units with a combined capacity of 18.2 million kilowatts will be in operation.