The Three Gorges Dam, the world’s largest hydropower project, might lose the battle against the worst drought to hit Central China in 50 years if no rains fall by mid-June.

“If the drought continues and there is no rainfall before June 10, the dam will lose the capacity to relieve the drought,” Wang Hai, director of the transport division of the China Three Gorges Corporation, told China Daily on Friday.

The dam’s water discharge rate is expected to reach 11,000 cubic meters a second on average (about 3,000 cubic meters a second more than the water flowing in) from May 25 to June 10, and its water level had fallen to less than 151.7 meters on Friday afternoon, according to the corporation.

The hydropower project is designed with a capacity of more than 22 billion cubic meters for drought relief and flood control. Ideally, the dam’s water level will reach the 175-meter mark in flooding season (generally from June to August) until early next year, when water will be gradually discharged to 145 meters, for drought relief.

Because the bottom-line for safe water transport in the upstream of the Yangtze River, the water transport hub, is 145 meters, Wang said.

More than 22 billion cubic meters of water are left for flood control and drought relief, but that might be far from enough for the severe drought hitting the down reaches.

As of Thursday, the drought had parched more than 6.2 million hectares, leaving more than 5 million people short of drinking water across the country, especially in Hubei, Hunan and Gansu provinces, according to the latest statistics released by the Office of State Flood Control and Drought Relief Headquarters.

“Although water levels of major lakes along the Yangtze River have gone up after the dam increased water discharges, we are still worried that the drought may continue and the water level will drop when less water is discharged from the dam after June 10,” Huang Qi, head of the disaster prevention and reduction office of the Yangtze River Water Resources Committee, said on Friday.

He added that if the drought gets more severe after June 10 and there is still no rain, the Three Gorges Dam may be forced to lower its water level below 145 meters.

The water levels of the Poyang and Dongting lakes rose by more than 2 meters on Friday due to the increasing water discharges from the dam, according to statistics from the committee.

The drought hit hard on the transportation on the Yangtze River.

The waterway between Wuhan and Wuhu is likely to close if the present water level remains, about 5 meters lower than the usual, said Wang Yong, deputy director of the waterway management department of the Changjiang (Yangtze River) Waterway Bureau.

Before June 2, no rains are predicted in the middle and lower reaches of the Yangtze River, and mild to medium rains are expected in parts of the region from June 2 to 3, according to the China Meteorological Administration.

By Wang Qian