The water level at the Three Gorges Dam, the world's largest water control and hydropower project, dropped to 170 meters on Tuesday, the lowest level after it reached its designed highest mark of 175 meters for the first time in October last year.

Zhao Yunfa, deputy chief engineer of the Three Gorges hydro-power control communication center, said the reservoir's water discharge would continue, and its water level was scheduled to fall to 155 meters in May and further drop to 146 meters in June.

The water discharges were aimed both for alleviating droughts in the downstream of the Yangtze River and for making room to contain water from seasonal flooding of the river in summer, he said.

Water control is one of the most important functions of the gigantic hydro-power project. Yangtze River has a low water level between November and March, when the river's downstream areas including China's economic powerhouses of Wuhan and Shanghai suffer water shortage.

Zhao said since the end of last year, the Three Gorges reservoir has discharged 5 billion cubic meters of water to the river's lower reaches as its water level dropped from 175 meters to 170 meters.